Values of macular ganglion cell-inner plexiform layer and 10-2 visual field measurements in detecting and evaluating glaucoma

AIM

To assess the performance of macular ganglion cell-inner plexiform layer thickness (mGCIPLT) and 10-2 visual field (VF) parameters in detecting early glaucoma and evaluating the severity of advanced glaucoma.

METHODS

Totally 127 eyes from 89 participants (36 eyes of 19 healthy participants, 45 eyes of 31 early glaucoma patients and 46 eyes of 39 advanced glaucoma patients) were included. The relationships between the optical coherence tomography (OCT)-derived parameters and VF sensitivity were determined. Patients with early glaucoma were divided into eyes with or without central 10° of the VF damages (CVFDs), and the diagnostic performances of OCT-derived parameters were assessed.

RESULTS

In early glaucoma, the mGCIPLT was significantly correlated with 10-2 VF pattern standard deviation (PSD; with average mGCIPLT: β=-0.046, 95%CI, -0.067 to -0.024, P<0.001). In advanced glaucoma, the mGCIPLT was related to the 24-2 VF mean deviation (MD; with average mGCIPLT: β=0.397, 95%CI, 0.199 to 0.595, P<0.001), 10-2 VF MD (with average mGCIPLT: β=0.762, 95%CI, 0.485 to 1.038, P<0.001) and 24-2 VF PSD (with average mGCIPLT: β=0.244, 95%CI, 0.124 to 0.364, P<0.001). Except for the minimum and superotemporal mGCIPLT, the decrease of mGCIPLT in early glaucomatous eyes with CVFDs was more severe than that of early glaucomatous eyes without CVFDs. The area under the curve (AUC) of the average mGCIPLT (AUC=0.949, 95%CI, 0.868 to 0.982) was greater than that of the average circumpapillary retinal nerve fiber layer thickness (cpRNFLT; AUC=0.827, 95%CI, 0.674 to 0.918) and rim area (AUC=0.799, 95%CI, 0.610 to 0.907) in early glaucomatous eyes with CVFDs versus normal eyes.

CONCLUSION

The 10-2 VF and mGCIPLT parameters are complementary to 24-2 VF, cpRNFLT and ONH parameters, especially in detecting early glaucoma with CVFDs and evaluating the severity of advanced glaucoma in group level.

Changes in retinal nerve fiber layer thickness may be the cause of post-COVID-19 headaches

OBJECTIVE

The prevalence of post-COVID headaches is not low. The eye can be affected by this infection, but it is not clear yet what the relationship is between persistent headaches and the thickness of the retinal nerve fiber layer (RNFL) after COVID-19 infection this study aims to investigate the relationship between these subjects.

METHODS

In this retrospective study, in patients who have had a persistent headache, SD-OCT analysis of RNFL was obtained, and RNLF thickness values before and after COVID-19 infection were analyzed.

RESULTS

A total of 26 eyes from 13 patients (nine (69.2%) females, four (30.8%) males) with persistent headaches after COVID-19 infection were studied. The average age was 47,35 years for females and 63 years for males. The mean RNFL thickness of both eyes between before and after COVID-19 infection decreased, which was statistically significant.

CONCLUSION

In this study, a correlation between headache and changes in RNLF after COVID-19 infection was found. It may have wider ramifications to look into the COVID-19-associated headache phenotype of people with a history of migraines, contributing to a more comprehensive understanding of migraine pathogenesis. This relationship can provide further insight into this infection.

Anti-vascular endothelial growth factor drugs combined with laser photocoagulation maintain retinal ganglion cell integrity in patients with diabetic macular edema: study protocol for a prospective, non-randomized, controlled clinical trial

The integrity of retinal ganglion cells is tightly associated with diabetic macular degeneration that leads to damage and death of retinal ganglion cells, affecting vision. The major clinical treatments for diabetic macular edema are anti-vascular endothelial growth factor drugs and laser photocoagulation. However, although the macular thickness can be normalized with each of these two therapies used alone, the vision does not improve in many patients. This might result from the incomplete recovery of retinal ganglion cell injury. Therefore, a prospective, non-randomized, controlled clinical trial was designed to investigate the effect of anti-vascular endothelial growth factor drugs combined with laser photocoagulation on the integrity of retinal ganglion cells in patients with diabetic macular edema and its relationship with vision recovery. In this trial, 150 patients with diabetic macular edema will be equally divided into three groups according to therapeutic methods, followed by treatment with anti-vascular endothelial growth factor drugs, laser photocoagulation therapy, and their combination. All patients will be followed up for 12 months. The primary outcome measure is retinal ganglion cell-inner plexiform layer thickness at 12 months after treatment. The secondary outcome measures include retinal ganglion cell-inner plexiform layer thickness before and 1, 3, 6, and 9 months after treatment, retinal nerve fiber layer thickness, best-corrected visual acuity, macular area thickness, and choroidal thickness before and 1, 3, 6, 9, and 12 months after treatment. Safety measure is the incidence of adverse events at 1, 3, 6, 9, and 12 months after treatment. The study protocol hopes to validate the better efficacy and safety of the combined treatment in patients with diabetic macula compared with the other two monotherapies alone during the 12-month follow-up period. The trial is designed to focus on clarifying the time-effect relationship between imaging measures related to the integrity of retinal ganglion cells and best-corrected visual acuity. The trial protocol was approved by the Medical Ethics Committee of the Affiliated Hospital of Beihua University with approval No. (2023)(26) on April 25, 2023, and was registered with the Chinese Clinical Trial Registry (registration number: ChiCTR2300072478, June 14, 2023, protocol version: 2.0).

Quantitative measurement of retinal nerve fiber layer thickness and its correlation with optical coherence tomography angiography vascular biomarker changes in preclinical diabetic retinopathy

PURPOSE

The present study was done to assess the use of optical coherence tomography angiography (OCTA) in detecting earlier stages of diabetic retinopathy and for the early management and effective blood glucose control in preclinical diabetic patients for preventing retinal nerve fiber layer (RNFL) thinning.

METHODS

A tertiary care center-based prospective observational study was conducted from the year 2021 to 2022 in the Department of Ophthalmology. The study included 50 cases and 50 controls. The parameters analyzed by using OCTA (Topcon 3D OCT-1 Maestro2) were RNFL thickness and peripapillary vessel density.

RESULTS

We found that the RNFL thickness in the temporal and superior disc in patients with preclinical diabetic retinopathy was significantly (0.041 and 0.044, respectively) decreased. The duration of diabetes and glycated hemoglobin (HbA1c) were the risk factors for peripapillary vessel density reduction in patients with preclinical diabetic retinopathy (P < 0.001).

CONCLUSION

RNFL thinning is an early sign of retinal neurodegeneration and is associated with peripapillary vessel density reduction. Early management and effective blood glucose control in diabetes patients may be beneficial for preventing RNFL thinning in superior and temporal disc.

Effect of Repeated Intravitreal Injections in Glaucoma Spectrum Diseases

Purpose

To evaluate whether repeated intravitreal injections (IVI) with an anti-vascular endothelial growth factor (anti-VEGF) agent are associated with glaucomatous progression in eyes with glaucoma spectrum diseases (GSD).

Methods

Single-center, retrospective, longitudinal study of patients with bilateral and similar GSD who: (1) received ≥8 IVI in only one eye during the study period; (2) had ≥2 retinal nerve fiber layer thickness (RNFL) measurements obtained by spectral-domain optical coherence tomography (SD-OCT) at least 12 months apart. The primary outcome was the absolute RNFL thickness change, comparing injected and fellow uninjected eyes. Linear mixed effects models were constructed, including a multivariable model.

Results

Sixty-eight eyes from 34 patients were included, 34 injected and 34 fellow uninjected eyes. Average baseline age was 67.68±21.77 years with a follow-up of 3.66±1.89 years and 25.12±14.49 IVI. RNFL thickness decreased significantly from 80.92±15.78 to 77.20±17.35 μm (p<0.001; -1.18±1.93 μm/year) in injected eyes and from 79.95±17.91 to 76.61±17.97 μm (p<0.001; -1.07±0.98 μm/year) in uninjected eyes. In a multivariable linear mixed model of injected eyes, only higher baseline RNFL thickness (p < 0.001) significantly predicted higher absolute RNFL thickness loss. Neither absolute RNFL thickness variation (p=0.716) nor RNFL rate (p=0.779) was significantly different between paired injected and uninjected eyes. Absolute IOP variation was not significantly different between groups (16.62±4.77 to 15.09±4.34 mmHg in injected eyes and 17.68±5.01 to 14.50±3.39 mmHg in fellow uninjected eyes; p=0.248). The proportion of eyes receiving glaucoma medical treatment increased significantly in both groups (55.9% to 76.5% in injected eyes; p=0.039; 58.8% to 76.5% in uninjected eyes; p = 0.031). The number of glaucoma medications also increased significantly in both groups (1.03±1.11 to 1.59±1.18 glaucoma medications in injected eyes; p=0.003; 1.09±1.11 to 1.56±1.19 glaucoma medications in uninjected eyes; p=0.003).

Conclusion

Repeated IVI do not seem to accelerate glaucomatous progression. Future studies with a longer follow-up are needed.

Artifact Correction in Retinal Nerve Fiber Layer Thickness Maps Using Deep Learning and Its Clinical Utility in Glaucoma

Purpose

Correcting retinal nerve fiber layer thickness (RNFLT) artifacts in glaucoma with deep learning and evaluate its clinical usefulness.

Methods

We included 24,257 patients with optical coherence tomography and reliable visual field (VF) measurements within 30 days and 3,233 patients with reliable VF series of at least five measurements over ≥4 years. The artifacts are defined as RNFLT less than the known floor value of 50 µm. We selected 27,319 high-quality RNFLT maps with an artifact ratio (AR) of <2% as the ground truth. We created pseudo-artifacts from 21,722 low-quality RNFLT maps with AR of >5% and superimposed them on high-quality RNFLT maps to predict the artifact-free ground truth. We evaluated the impact of artifact correction on the structure-function relationship and progression forecasting.

Results

The mean absolute error and Pearson correlation of the artifact correction were 9.89 µm and 0.90 (P < 0.001), respectively. Artifact correction improved R2 for VF prediction in RNFLT maps with AR of >10% and AR of >20% up to 0.03 and 0.04 (P < 0.001), respectively. Artifact correction improved (P < 0.05) the AUC for progression prediction in RNFLT maps with AR of ≤10%, >10%, and >20%: (1) total deviation pointwise progression: 0.68 to 0.69, 0.62 to 0.63, and 0.62 to 0.64; and (2) mean deviation fast progression: 0.67 to 0.68, 0.54 to 0.60, and 0.45 to 0.56.

Conclusions

Artifact correction for RNFLTs improves VF and progression prediction in glaucoma.

Translational Relevance

Our model improves clinical usability of RNFLT maps with artifacts.

Segmentation Errors and Off-Center Artifacts in SS-OCT: Insight from a Population-Based Imaging Study

PURPOSE

To evaluate the frequency and associated factors of artifacts in swept-source optical coherence tomography (SS-OCT) imaging.

METHODS

This was a population-based cross-sectional study. Individuals aged 35 years or older, residing in the Yuexiu district of Guangzhou, China, were recruited by random cluster sampling. Nearly half of the participants were randomly selected for SS-OCT imaging centered on the optic nerve head. Six types of artifacts in the peripapillary choroidal layer and retinal nerve fiber layer (RNFL) were graded and identified. Univariate and multivariate logistic regression analyses were used to investigate the association between the presence of artifacts and clinical characteristics.

RESULTS

Out of the 616 eligible individuals who underwent SS-OCT imaging, 18.3% and 13.6% of subjects exhibited at least one artifact in peripapillary RNFL (pRNFL) and peripapillary choroidal thickness (pCT) measurements, respectively, with posterior segmentation error and off-center artifact ranked as the most common artifacts. The presence of artifacts was significantly associated with age (odds ratio [OR], 1.03; 95% confidence interval [CI], 1.01-1.06; p = .003), refractive error (OR, 0.80; 95% CI, 0.71-0.89; p < .001), and signal strength (OR, 0.95; 95% CI, 0.90-0.997; p = .039) in pRNFL thickness measurement. Similarly, the presence of artifacts in pCT measurement was significantly associated with age (OR, 1.05; 95% CI, 1.03-1.08; p < .001), and refractive error (OR, 0.76; 95% CI, 0.68-0.86; p < .001).

CONCLUSION

Nearly one-fifth of the eyes were noted with at least one artifact in the population-scale SS-OCT study. Age was a risk factor for the presence of artifacts and should be considered in clinical settings.

Correlation between degree of sagittal suture fusion and surrogates of elevated intracranial pressure in sagittal craniosynostosis

OBJECTIVE

Sagittal craniosynostosis constricts transverse skull growth, with possible neurocognitive sequelae. While the degree of sagittal suture fusion has been shown to influence the degree of dysmorphology, it is unknown if it impacts functional findings, including elevated intracranial pressure (ICP). The purpose of this study was to determine associations between the degree of sagittal suture fusion and optical coherence tomography (OCT) surrogates suggestive of increased ICP in patients with nonsyndromic sagittal craniosynostosis.

METHODS

Three-dimensional CT head images of patients with sagittal craniosynostosis were analyzed in Materialise Mimics and parietal bones were manually isolated to determine the percentage fusion of the sagittal suture. Retinal OCT was performed prior to the cranial vault procedure with analysis for thresholds that correlate with elevated ICP. The degree of sagittal suture fusion was compared with OCT retinal parameter measurements using Mann-Whitney U-tests, Spearman's correlations, and multivariate logistic regression models controlled for age.

RESULTS

Forty patients (31 males) with nonsyndromic sagittal craniosynostosis at a mean (± SD) age of 3.4 ± 0.4 months were included in this study. OCT surrogates of elevated ICP (maximal retinal nerve fiber layer [RNFL] thickness and maximal anterior projection [MAP]) were not associated with total sagittal suture fusion (p > 0.05). Maximal RNFL thickness was positively associated with increased percentage of posterior one-half (rho = 0.410, p = 0.022) and posterior one-third (rho = 0.417, p = 0.020) sagittal suture fusion. MAP was also positively associated with increased percentage of posterior one-half (rho = 0.596, p < 0.001) and posterior one-third (rho = 0.599, p < 0.001) sagittal suture fusion. Multivariate logistic regression models revealed increased percentage of posterior one-half (p = 0.048) and posterior one-third (p = 0.039) sagittal suture fusion predicted ICP > 20 mm Hg.

CONCLUSIONS

Increased percentage fusion of the posterior sagittal suture, but not total suture, was positively associated with retinal changes indicative of increased ICP. These findings suggest suture fusion leading to increased ICP may be region specific.

Effect of nutritional-deficiency anemia on peripapillary retinal nerve fiber layer: A North Indian study

PURPOSE

The purpose of this study was to evaluate the effect of nutritional-deficiency anemia (NDA) on peripapillary retinal nerve fiber layer thickness (PPRNFLT) using spectral-domain optical coherence tomography and to determine any correlation arising thereof. This was a single-center, cross-sectional, observational study.

MATERIALS AND METHODS

A total 115 eyes of 115 NDA patients (50 of each with iron-deficiency anemia [IDA] and Vitamin B12-deficiency anemia [BDA], and 15 with folic acid-deficiency anemia [FDA]) aged 18-65 years were compared with a total 100 eyes of 50 age- and sex-matched healthy controls. All subjects underwent comprehensive clinical, ophthalmic, and hematological evaluation, followed by PPRNFLT assessment for the mean total, superior, inferior, nasal, and temporal quadrants.

RESULTS

PPRNFLT for the mean total and all four quadrants in IDA patients, for the mean total, inferior, nasal, and temporal quadrants in BDA patients, and for the mean total, inferior, and nasal quadrants, in FDA patients, was significantly lower as compared to the controls (P < 0.05). The mean total PPRNFLT of all NDA patients correlated significantly (P < 0.05) with their relevant hematological parameters with Pearson's coefficient (r) value of 0.613, 0.610, 0.336, 0.295, 0.337, 0.374, and - 0.509, respectively, for serum haemoglobin (Hb), iron, ferritin, mean corpuscular volume (MCV), mean cell hemoglobin, mean corpuscular hemoglobin concentration, and total iron binding capacity in IDA; 0.310, 0.435, and - 0.386, respectively, for serum Hb%, Vitamin B12, and MCV in BDA; and 0.557, 0.358, and - 0.294 for Hb%, folate, and MCV, respectively, in FDA cases. Mean total retinal nerve fiber layer thinning of all NDA patients showed progression with the increasing severity grades of anemia, except in very severe BDA where an inverse relationship was documented.

CONCLUSION

Our study revealed that PPRNFLT is significantly thinner in all NDA patients (total and all four quadrants in IDA; total, inferior, nasal, and temporal in BDA; and total, inferior, and nasal in FDA) correlating well with their relevant hematological parameters. Early detection of this may be crucial in preventing potential blinding sequelae and differentiating glaucomatous and other neuro-ophthalmic disorders.

A cross-sectional study analyzing the correlation between the mean retinal nerve fiber layer and ganglion cell layer thickness with axial length and refractive errors among children aged 5-15 years

Purpose

To analyze the correlation between the mean retinal nerve fiber layer (RNFL) and ganglion cell layer (GCL) thickness with axial length and refractive errors among children aged 5-15 years.

Methods

This cross-sectional, observational study was done on 130 eyes of 65 consecutive subjects with refractive errors. The patients were evaluated for RNFL thickness and macular GCL thickness using spectral domain- optical coherence tomography.

Results

One hundred and thirty eyes of 65 subjects aged between 5 and 15 years were divided into three groups based on their spherical equivalent in diopters (D). The children with a spherical equivalent of ≤-0.50 D were considered myopic, ≥-0.5 to ≤+0.5 D were considered emmetropic, and ≥+0.50 D were considered hypermetropic. RNFL thickness and GCL thickness were correlated with age, gender, spherical equivalent, and axial length. The mean global RNFL thickness was 104.58 μm ± 7.567.

Conclusion

There exists a negative correlation between RNFL thickness and macular GCL thickness with increasing severity of myopia and increase in axial length, and the possible reason could be stretching of the sclera, which further leads to stretching of the retina, resulting in thinner RNFL and macular GCL thickness.

OCT Findings in Patients with Methamphetamine Use Disorder

PURPOSE

In the present study, the purpose was to examine the results of optical coherence tomography (OCT) measurements in patients diagnosed with methamphetamine use disorder (MUD) by comparing them with healthy controls.

MATERIALS AND METHODS

A total of 114 eyes were evaluated in this study (27 patients and 30 control group participants). After detailed biomicroscopic examinations of all participants by the same ophthalmologist, both eyes were evaluated by OCT. The retinal nerve fiber layer thickness (RNFL) and macular thickness were calculated from OCT.

RESULTS

No statistically significant differences were detected between the demographic data of the patient and control groups (p > 0.05). When OCT findings were evaluated, macular thickness and volume were not different between the groups (p > 0.05). With respect to RNFL, the left eye superior, inferior, temporal, and nasal quadrants, as well as the left eye's total measurements were found to be thicker than those of controls (p < 0.05). In both eyes, the left eye nasal quadrant and APIS total score were negatively correlated, the total RNLF measurement of the right eye and APIS motivation subscale score were negatively correlated, central macular thickness and the APIS motivation subscale score were positively correlated, and the APIS substance use characteristics subscale score and left eye temporal quadrant RNLF measurement were positively correlated.

CONCLUSION

Our study is the first to evaluate addiction severity and OCT findings in MUD. However, this study needs to be supported by further studies so that OCT findings, which can be used as an effective method for demonstrating possible neurodegeneration in methamphetamine use disorder, gain importance.

Baseline retinal nerve fiber layer thickness as a predictor of multiple sclerosis progression: New insights from the FREEDOMS II study

BACKGROUND AND PURPOSE

The aim was to evaluate the potential of retinal nerve fiber layer thickness (RNFLT) measured with optical coherence tomography in predicting disease progression in relapsing-remitting multiple sclerosis (RRMS).

METHODS

Analyses were conducted post hoc of this 24-month, phase III, double-blind study, in which RRMS patients were randomized (1:1:1) to once daily oral fingolimod 0.5 mg, 1.25 mg or placebo. The key outcomes were the association between baseline RNFLT and baseline clinical characteristics and clinical/imaging outcomes up to 24 months. Change of RNFLT with fingolimod versus placebo within 24 months and time to retinal nerve fiber layer (RNFL) thinning were evaluated.

RESULTS

Altogether 885 patients were included. At baseline, lower RNFLT was correlated with higher Expanded Disability Status Scale score (r = -1.085, p = 0.018), lower brain volume (r = 0.025, p = 0.006) and deep gray matter volume (r = 0.731, p < 0.0001), worse visual acuity (r = -19.846, p < 0.0001) and longer duration since diagnosis (r = -0.258, p = 0.018). At month 12, low baseline RNFLT (<86 μm) versus high baseline RNFLT (≥99 μm) was associated with a greater brain volume loss (percentage change -0.605% vs. -0.315%, p = 0.035) in patients without optic neuritis history. At month 24, low baseline RNFLT versus high baseline RNFLT was associated with a higher number of new or newly enlarged T2 lesions (mean number 4.0 vs. 2.8, p = 0.014) and a higher risk of subsequent RNFL thinning (hazard ratio 2.55; 95% confidence interval 1.84-3.53; p < 0.001). The atrophy of the RNFL in the inferior quadrant was alleviated with fingolimod 0.5 mg versus placebo at month 24 (Δ(least squares mean) = 1.8, p = 0.047).

CONCLUSION

Retinal nerve fiber layer thickness could predict disease progression in RRMS.

TRIAL REGISTRATION

Clinicaltrials.gov identifier: NCT00355134, https://clinicaltrials.gov/ct2/show/NCT00355134.

Optical Coherence Tomography Retinal Nerve Fibre Layer and Ganglion Cell Complex Measurements in Normal Southern Nigerian Eyes

Introduction Glaucoma is the leading cause of irreversible blindness worldwide. It is more severe in people with African heritage, and intraocular pressure remains the only modifiable risk factor in managing glaucoma. Attempts to improve the diagnosis and monitoring of glaucoma are ongoing. One of those attempts is the development of optical coherence tomography (OCT). However, there is a theoretical possibility of a delayed or wrong diagnosis of glaucoma using the OCT because of racial, age, and sex differences in the RNFL (retina nerve fibre layer), GCL (ganglion cell layer), and GCL+IPL (ganglion cell layer and inner plexiform layer) thickness. Objective This study aims to provide the measurements of RNFL, GCL, and GCL+IPL in normal eyes of southern Nigerian patients and specifically to evaluate the relationship of these measurements to gender, age, intra-eye variability, and the Topcon SD-OCT normative database. Method Three hundred and four eyes of 152 patients who had normal OCT scans using the 6x6 RNFL (four sectors) and Macula scans of the Topcon OCT-1 3D Maestro OCT machine were included for analysis. Parametric tests were used to interrogate the relationship between normally distributed parameters and gender, age, and the Topcon reference database. Non-parametric tests were used for non-normally distributed data. Results The male-to-female ratio was 1:1, and ages ranged between 18 and 71 for both genders. The average RNFL values were 111.49 ± 10.44 (right eye - RE) and 111.96 ± 9.66 (left eye - LE). For the GCL, average values were 66.23 ± 4.4 (RE) and 66.34 ± 4.19 (LE). GCL+IPL values were 104.02 ± 6.71 (RE) and 103.89 ± 6.66 (LE). There was no difference between genders (X² = 56.467; df = 46; p = 0.160), and RNFL, GCL, and GCL+IPL values showed a significant reduction as the age of the respondents increased. There was a significant difference between RNFL, GCL, and GCL+IPL values and the Topcon reference database, p < 0.001. Conclusion Significant differences exist between the Southern Nigerian eyes' RNFL, GCL, and GCL+ IPL values and the Topcon OCT-1 3D Maestro reference database. While randomised control trials and extensive multi-centre studies have not been conducted to determine the possible effects of these differences between measured values and reference databases of the OCTs, they need to be considered while diagnosing and managing glaucoma with the OCT.

Ganglion cell complex and retinal nerve fiber layer thickness in gestational diabetes mellitus

PURPOSE

The purpose of this study was to compare ganglion cell complex and peripapillary retinal nerve fiber layer (RNFL) thickness between pregnant females with gestational diabetes mellitus (GDM) and healthy pregnant females.

MATERIALS AND METHODS

This was a single-center, prospective, analytical cross-sectional study including pregnant females with a gestational age of 24 weeks or more in the GDM and control groups. The GDM group included 162 pregnant females with GDM, and the control group included 162 healthy pregnant females. Peripapillary RNFL (pRNFL), macular RNFL (mRNFL), GCL+ (ganglion cell layer [GCL] + inner plexiform layer [IPL]), and GCL++ (mRNFL + GCL + IPL) thickness were analyzed using spectral-domain optical coherence tomography (OCT), and comparisons were made between the groups.

RESULTS

Both the groups had similar mean age (P = 0.219), intraocular pressure (P = 0.186), central corneal thickness (P = 0.689), Schirmer test value (P = 0.931), and tear breakup time (P = 0.651). The mean pRNFL thickness of the GDM and control groups was 100.75 ± 8.36 μm and 106.77 ± 8.44 μm (P < 0.0001). pRNFL was significantly thinner in all four quadrants (P < 0.05) in the GDM compared to the control group. We observed that the mean mRNFL, GCL+, and GCL++ thickness were significantly reduced in GDM in comparison to the control group (P < 0.05).

CONCLUSION

Our study showed that OCT plays an indispensable role in determining initial retinal changes caused by GDM before the development of diabetic retinopathy.

Analysis of retinal vasculature changes in indirect traumatic optic neuropathy using optic coherence tomography angiography

AIM

To assess the retinal vasculature alterations in indirect traumatic optic neuropathy (ITON) patients following craniofacial trauma by optic coherence tomography angiography (OCTA).

METHODS

Patients diagnosed of monocular ITON were recruited from August 2016 to May 2020. OCTA was performed using the AngioVue OCT-A system for two cube scans centered at the optic nerve head and fovea. OCTA data included thicknesses of peripapillary retinal nerve fiber layer (RNFL) and macular ganglion cell complex (GCC), as well as proportion of capillary perfusion and data were analyzed for correlation with post-injury timepoints: within 7, 8-30, 31-90, and 91-365d.

RESULTS

A total of 73 ITON patients were studied. Significant thinning of RNFL and GCC layers and attenuation of microvascular perfusion were observed in ITON eyes as compared to contralateral unaffected eyes (for most of the analyzed sectors and quadrants, P<0.05). Without respect to surgical intervention and vision recovery, the decrease in retinal layer thicknesses and microvascular perfusion was time-dependent, and most significant within three months (P<0.001).

CONCLUSION

ITON presents with time-dependent thinning of retinal layers and attenuation of microvasculature, indicating possible degeneration of retinal ganglion cells due to reduced retinal blood supply.

Machine learning classification of multiple sclerosis in children using optical coherence tomography

BACKGROUND

In children, multiple sclerosis (MS) is the ultimate diagnosis in only 1/5 to 1/3 of cases after a first episode of central nervous system (CNS) demyelination. As the visual pathway is frequently affected in MS and other CNS demyelinating disorders (DDs), structural retinal imaging such as optical coherence tomography (OCT) can be used to differentiate MS.

OBJECTIVE

This study aimed to investigate the utility of machine learning (ML) based on OCT features to identify distinct structural retinal features in children with DDs.

METHODS

This study included 512 eyes from 187 (n_eyes = 374) children with demyelinating diseases and 69 (n_eyes = 138) controls. Input features of the analysis comprised of 24 auto-segmented OCT features.

RESULTS

Random Forest classifier with recursive feature elimination yielded the highest predictive values and identified DDs with 75% and MS with 80% accuracy, while multiclass distinction between MS and monophasic DD was performed with 64% accuracy. A set of eight retinal features were identified as the most important features in this classification.

CONCLUSION

This study demonstrates that ML based on OCT features can be used to support a diagnosis of MS in children.

Choroidal vascularity index and thickness in sarcoidosis

Sarcoidosis is a multisystem granulomatous disease which is observed worldwide. Sarcoidosis is one of the common causes of ocular inflammation. The choroidal vascularity index, defined as the ratio of the luminal area to the total choroidal area, is used as one of the biomarkers for assessing the choroid vascular state. We aimed to compare choroidal vascularity index and thickness measurements between sarcoidosis patients and healthy controls.Thirty-one patients with sarcoidosis and 31 age-gender matched healthy participants were recruited in this cross-sectional and comparative study. Choroidal vascularity index was defined as the ratio of luminal area to total choroidal area after binarization on optical coherence tomography images. Anterior segment examinations included central corneal thickness, corneal volume, anterior chamber depth, anterior chamber volume, and iridocorneal angle. Spectral-domain optical coherence tomography was used to measure peripapillary retinal nerve fiber layer thickness, choroidal thickness, and retinal vessel caliber.The mean choroidal vascularity index value was 61.6% in sarcoidosis patients and 62.4% in healthy controls (P = .69). The choroidal vascularity index and thickness were significantly correlated in both sarcoidosis (r = 0.41, P = .026) and control groups (r = 0.51, P = .006). Both the sarcoidosis and control groups had similar measured values for central corneal thickness, corneal volume, anterior chamber depth, anterior chamber volume, and iridocorneal angle (P > .05). Mean retinal nerve fiber layer, retinal arteriole and venule caliber, and choroidal thickness measurements did not differ significantly between the groups (P > .05).Sarcoidosis patients in quiescent period have similar choroidal vascularity index and thickness with healthy controls.

Optical Coherence Tomography Angiography Compared With Optical Coherence Tomography for Detection of Early Glaucoma With High Myopia

Purpose: To investigate the diagnostic abilities of the perfusion density (PD) and structural thickness parameters in the peripapillary and macular regions measured by optical coherence tomography angiography (OCTA) and optical coherence tomography (OCT) and to test if their diagnostic abilities of early glaucoma are different between highly myopic (HM) and non-highly myopic (NHM) patients. Methods: A total of 75 glaucoma patients and 65 controls were included in the analyses. The glaucoma detection abilities of macular PD and peripapillary PD, along with macular ganglion cell-inner plexiform layer (mGCIPL) thickness and peripapillary retinal nerve fiber layer (pRNFL) thicknesses were compared between the HM and NHM group. Diagnostic ability was assessed by area under the receiver operating characteristics (AUC) curves, adjusted by age, axial length, and signal strength. Results: The diagnostic ability of macular PD and mGCIPL thickness had no significant difference in both HM and NHM groups. However, the diagnostic ability of peripapillary PD except in the temporal section was significantly lower in the HM group than in the NHM group (all p < 0.05). The diagnostic ability of the superior, nasal, and average pRNFL thickness was also significantly lower in the HM group than in the NHM group (all p < 0.05). Conclusion: This study demonstrated that although peripapillary PD and macular PD were both significantly reduced in patients with highly myopia, the diagnostic ability of peripapillary PD in HM patients was significantly lower than that in NHM patients, while macular PD was not. Macular OCTA along with OCT imaging should be included in the imaging algorithm in early glaucoma diagnosis in highly myopic patients.

Retinal nerve fiber layer thickness and retinal vascular caliber alterations in coal miners in northern China: a community-based observational study

AIM

To evaluate retinal nerve fiber layer thickness and retinal vascular caliber alterations in coal mine workers.

METHODS

The community-based observational cross-sectional study included 4004 participants of a sub-population of the Kailuan Study. All the study participants underwent structured interviews with a standardized questionnaire, fundus photography and spectral-domain optical coherence tomography (OCT) examinations performed by trained doctors.

RESULTS

The retinal nerve fiber layer thickness was significantly higher (P=0.006) and the central macular thickness was lower in coal miners (n=659, 51.0±7.8y) as compared to the control (working above the ground; n=477, 51.8±7.5y; P=0.032). Additionally, the downhole workers showed a significantly thicker retinal artery (P=0.012) and vein diameters (P<0.001). In multivariable regression, a thicker retinal nerve fiber layer was associated with a higher cumulative silica dust exposure (P=0.005) after adjusting for younger age and larger spherical equivalent. In a reverse pattern, a higher cumulative silica dust exposure (P=0.004) was significantly associated with a thicker retinal nerve fiber layer after adjusting for age, high-density lipoproteins and uric acid. Wider retinal vein diameters were associated with higher cumulative silica dust exposure (P=0.036) after adjusting for younger age and larger spherical equivalent.

CONCLUSION

The retinal vessels diameters and retinal nerve fiber layer thickness are significantly thicker in long term of coal mining. The results of our study indicate that underground working environment may lead to retinal vessel dilation and inflammation. Thus, ocular examination might be needed within coal miners in order to monitor the occupational eye health as well as the incidence and progression of eye diseases.

Assessment of Optical Coherence Tomography Findings in Adults with Attention Deficit Hyperactivity Disorder: A Case-Control Study

Background

To assess retinal nerve fiber layer and ganglion cell-inner plexiform layer thickness using optical coherence tomography in attention deficit hyperactivity disorder adults on regular methylphenidate treatment, comparing them to healthy controls.

Methods

A total of 33 attention deficit hyperactivity disorder adults and 31 healthy subjects, matched for age, gender, and education (control group), were included in this study. Retinal nerve fiber layer and ganglion cell-inner plexiform layer thickness of both eyes were measured using optical coherence tomography, and symptom severity was evaluated using Adult Attention Deficit Hyperactivity Disorder Self-Report Scale and Wender Utah Rating Scale.

Results

There was no significant difference in retinal nerve fiber layer thickness between the attention deficit hyperactivity disorder and control groups (P > .05). Thinner ganglion cell-inner plexiform layer total (P = .044), inferior (P = .012), and inferior nasal quadrant thickness (P = .049) were observed in attention deficit hyperactivity disorder patients as compared to the controls.

Conclusion

Findings detected thinner ganglion cell-inner plexiform layer in some quadrants of attention deficit hyperactivity disorder adults, indicating an early disorder in retinal structure development. Whether retinal structures are sensitive attention deficit hyperactivity disorder biomarkers should be supported and investigated in future multimodal studies.

Multifocal visual evoked potential for evaluation of open-angle glaucoma

Background

To correlate multifocal visual evoked potential (mfVEP) findings with static automated perimetry (SAP) and spectral-domain optical coherence tomography (SD-OCT) in eyes with primary open- angle glaucoma (POAG).

Methods

This cross-sectional study included a consecutive sample of 40 eyes of 40 patients with POAG. The participants underwent a complete ophthalmologic assessment, axial length (AL) measurement, and assessments with SAP, SD-OCT, and mfVEP.

Results

POAG cases were aged 49.70 (14.16) years (mean [SD]) and most were females (n = 24, 60%). For eyes of patients with POAG, the mfVEP upper-ring signal-to-noise ratio (SNR) showed a significant negative correlation with best-corrected logMAR visual acuity (r = - 0.33; P = 0.038), and a significant positive correlation with the superior hemifield of the visual field (VF) and the inferior-quadrant retinal nerve fiber layer (RNFL) thickness (r = + 0.34; P = 0.030; r = + 0.51; P < 0.001, respectively). Similarly, the mfVEP lower-ring SNR showed a significant negative correlation with best-corrected logMAR visual acuity (r = - 0.36; P = 0.024) and a significant positive correlation with the inferior hemifield of the VF and superior quadrant RNFL thickness (r = + 0.55; P < 0.001 and r = + 0.70; P < 0.001, respectively).

Conclusions

mfVEP is a promising tool for objective assessment of the VF in patients with POAG, as it is positively correlated with the VF and OCT RNFL thickness. Future longitudinal studies with a larger sample size and a specific glaucoma subtype, along with multiple follow-up evaluations, are warranted to confirm our preliminary results.

Examination of optical coherence tomography findings in patients with methamphetamine use disorder

OBJECTIVE

In our study, we aimed to examine Optical Coherence Tomography (OCT) findings in patients diagnosed with methamphetamine use disorder (MUD) by comparing them with healthy controls.

METHODS

Sixty-five people were included in our study and 130 eyes were evaluated; 33 cases were included in the patient group with MUD according to DSM-5 diagnostic criteria and 32 as the healthy control group. Detailed biomicroscopic examinations and then both eyes were evaluated through OCT by the same ophthalmologist.

RESULTS

There was no statistically significant difference between the patient and control groups in terms of gender and age (p > 0.05). When the OCT findings were evaluated, the measurements of the patients in any quadrant for retinal nerve fiber layer (RNFL) were not statistically different from the control group (p > 0.05). Macula and choroidal layer thickness did not differ between the groups (p > 0.05). Only right intraocular pressure was found to be decreased in the patient group (p = 0.026).

CONCLUSIONS

There are a limited number of studies examining OCT findings in patients with MUD. Visual symptoms and intraocular pressure should be considered when evaluating patients with MUD and planning their treatment. In addition; in order for OCT findings to gain importance, which can be used as an effective method to show the possible neurodegeneration that may occur in substance use disorder, it should be supported with further research.

Evaluation of Macular Thickness, Retinal Nerve Fiber Layer and Ganglion Cell Layer Thickness in Patients among Type 2 Diabetes Mellitus Using Optical Coherence Tomography

BACKGROUND

Vascular abnormalities and microvasculopathy are one of the widely accepted factors of diabetic retinopathy (DR). Retinal Neuronal dysfunction and neurodegeneration are also important components in the pathogenesis of DR. However recent investigations show neurodegenerative alterations before the appearance of microvascular changes in patients having DR.

AIMS AND OBJECTIVES

(1) To measure the macular thickness, retinal nerve fiber layer thickness, and ganglion cell complex thickness among patients with type 2 diabetes mellitus using optical coherence tomography. (2) To compare the macular thickness, retinal nerve fiber layer thickness and ganglion cell complex thickness in type 2 diabetic patients with and without DR with normal controls using optical coherence tomography.

MATERIALS AND METHODS

Thirty Patients with type 2 diabetes mellitus without DR, 30 having mild and moderate DR and 30 healthy normals are taken considering the inclusion and exclusion criteria. Macular thickness, retinal nerve fiber layer (RNFL) thickness, ganglion cell layer-inner plexiform layer (GCL-IPL) thickness was measured in each individual and it was compared using one way ANOVA test, post hoc test and Pearson correlation was performed to evaluate the linear correlation between variables and calculated P < 0.05 was regarded as its significance.

RESULTS

The average RNFL thickness was 90.27 ± 5.57 and 107.7 ± 5.32 um in diabetic patients and controls respectively (P < 0.001). Furthermore, for two different groups of diabetic patients, the average RNFL thickness was 89.92 ± 6.62 um in the no DR group and 78.6 ± 3.93 in the DR group (P = 0.339). The average GCL-IPL thickness was 82.65 ± 2.25 um and 92.10 ± 2.41 um in diabetic patients and controls, respectively (P < 0.001). Furthermore, for two different groups of diabetic patients, the average GCL-IPL thickness was 82.22 ± 2.11 um in the no DR group and 71.55 ± 2.34 in the DR group (P = 0.535). The average macular thickness was 238.03 ± 4.42 and 277.9 ± 5.85 um in diabetic patients and controls, respectively (P < 0.001). Furthermore, for two different groups of diabetic patients, the average macular thickness was 236.56 ± 4.10 um in the no DR group and 242.8 ± 4.95 um in the DR group (P = 0.585).

CONCLUSION

There was a statistically significant reduction of mean RNFL, GCL-IPL and macular thickness in type 2 diabetic patients with no DR compared with a homogenous control group indicating neuroretinal changes occur before vascular changes of DR.

Change of Retinal Vessels in Different Sectors of the Parapapillary Area in Primary Open-Angle Glaucoma

Purpose: To investigate the changes in the retinal vessels (RVs) in different sectors in patients with primary open-angle glaucoma (POAG), and their possible correlations with retinal nerve fiber layer thickness (RNFLT) and visual-field defects in the temporal parapapillary region.

Methods: The RV diameters, RNFLTs, and visual-field parameters were measured. The temporal parapapillary region was divided into the temporal (T, 315°-45°), temporal superior (TS, 45°-90°), and temporal inferior sectors (TI, 270°-315°). The changes in the RV diameters in each sector were determined, and their relationships with RNFLT, the mean deviation (MD), and visual field sensitivity (VFS) were examined.

Results: Fifty POAG patients (50 eyes) and 50 healthy subjects (50 eyes) were included. Compared with the healthy subjects, the POAG group had a significantly smaller accumulated parapapillary RV diameter (P < 0.001), which was positively correlated with the MD and RNFLT. When the different temporal sectors were examined, the accumulated RV diameters were significantly smaller in the POAG group than in the healthy controls in the TI and T sectors, but not in the TS sector. The accumulated diameters in the TI and T sectors were correlated with the corresponding RNFLTs (all P < 0.05), but only the accumulated diameter in the TI sector was correlated with the VFS.

Conclusions: In POAG, the changes in the RVs differed between different temporal sectors, with the most prominent changes occurring in the TI and T sectors.

Correlation between retinal nerve fibre layer thickness and white matter lesions in Alzheimer's disease

OBJECTIVES

Early diagnosis in Alzheimer's disease (AD) is crucial in order to implement new therapeutic strategies. The retina is embryologically related to the brain. Thus, the possible usefulness of optical coherence tomography (OCT) in the early detection of AD is currently being studied. Our aim was to study the relationship between retinal nerve fiber layer (RNFL) thickness and AD.

METHODS

We undertook an observational, analytical, cross-sectional study with consecutive sampling of 32 patients with AD or mild cognitive impairment and a group of healthy controls (C). The total number of eyes studied was 64. An ophthalmological and a comprehensive neuropsychological evaluation were performed in all participants. Quantification of white matter lesions and study of atrophy of the hippocampus by cerebral magnetic resonance were also performed.

RESULTS

We observed a significant linear trend towards a thinning of RNFL as the degree of cognitive deterioration increased, in the superior and temporal quadrants of the retina. A significant correlation was also noted between the mean thickness of the RNFL of the left temporal quadrant and occipital white matter lesions (r = -0.579, p = 0.038).

CONCLUSIONS

OCT could be a safe, rapid noninvasive tool providing useful biomarkers in the early detection of cognitive deterioration and AD.

Dry eye disease and retinal nerve fiber layer changes in chronic smokers

Purpose:

To study the effect of smoking on tear film parameters and retinal nerve fiber layer thickness (RNFL) in chronic smokers.

Methods:

This was a cross-sectional study, which included 60 (120 eyes) smokers who have smoked at least 10 pack-year and an equal number of healthy subjects as a control for comparison. In addition to history, a detailed slit-lamp examination was done to evaluate the anterior and posterior segments. All patients underwent Schirmer’s I test (SIT) with Whatman-41 filter paper, tear meniscus height (TMH), and RNFL with a Fourier-domain optical coherence tomography (OCT) and tear film breakup time (TBUT) with 2% fluorescein and cobalt blue filter using slit-lamp biomicroscopy.

Results:

The (mean ± SD) age of the participants was 56.48 ± 10.38 years. There was a statistically significant reduction in tear film parameters in smokers compared to nonsmokers (P = 0.000). The incidence of MGD was found to be higher in smokers when compared to nonsmokers with a P value of 0.000. RNFL in all four quadrants was also significantly reduced in smokers compared to nonsmokers (P = 0.00).

Conclusion:

This study shows that chronic smoking leads to an increased incidence of dry eye disease and is associated with RNFL thinning. Smoking can result in cumulative RNFL loss in patients with ocular neurodegenerative disorder and OCT of these patients may have to be interpreted keeping this in mind.

Neutrophil-to-lymphocyte and platelet-to-lymphocyte ratios as inflammation markers in patients with papilledema due to idiopathic intracranial hypertension

Purpose:

The aim of this study was to investigate the role of inflammation in the pathogenesis of idiopathic intracranial hypertension (IIH) using the neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) as inflammation markers.

Methods:

The files of 33 IIH patients and 33 controls were screened for this retrospective study. For each patient, the NLR and PLR values were calculated using a single fasting blood sample. For both eyes, papilledema (PE) grades, best-corrected visual acuity (BCVA), retinal nerve fiber layer thickness (RNFLT), and ganglion cell layer thickness (GCLT) measurements were recorded along with the demographic data, including body mass index (BMI), and complete neurological and ophthalmological findings. Comparisons between the two groups and between the IIH patients with and without PE were made. The associations of NLR and PLR with all other parameters were analyzed independently from age, gender, and BMI.

Results:

NLR and PLR were higher in patients with IIH than controls (P < 0.05). They were also higher in patients with PE (P < 0.05) in the IIH group. NLR and PLR were found to be associated with BCVA (P < 0.001 and P = 0.023, respectively), global RNFLT (P = 0.004 and 0.012, respectively), RNFLT of the temporal quadrant (P < 0.001 and P = 0.042, respectively) and PE grade (P < 0.001 and P = 0.035, respectively).

Conclusion:

The NLR and PLR values and their associations with BCVA, RNFLT, and PE support the hypothesis that inflammation is a very important component of the pathogenesis of IIH.

Evaluation of the choroidal thickness and retinal nerve fiber layer and visual fields in morbid obesity: Does bariatric surgery affect retinal structure and function?

Purpose

The study aimed to investigate the changes in choroidal thickness (CT), retinal nerve fiber layer thickness (RNFL), and visual field parameters in morbidly obese patients following bariatric surgery.

Methods

The study included 40 morbidly obese patients with body mass indexes (BMI) ≥40 who had undergone bariatric surgery (Group 1) and 40 age-and sex-matched healthy subjects with normal BMI values (Group 2). RNFL and CT measurements by optical coherence tomography (OCT) and visual field test were performed preoperatively and the 1^st, 6^th, and 12th months postoperatively. CT measurements were obtained from the subfoveal, nasal (N), and temporal (T) regions at distances of 500 μm and 1,000 μm from the fovea.

Results

No significant pathology was detected during ophthalmological examinations following bariatric surgery. The BMIs were found to be significantly lower in all of the periods after bariatric surgery (P < 0.0001). The CT measurements decreased significantly in all periods after bariatric surgery (P < 0.0001). No differences were found in terms of the mean RNFL thicknesses in all postoperative periods (P = 0.125). Visual field tests showed no significant changes during scheduled visits. (P = 0.877). No visual field defect was detected in any patient during the follow-up periods after bariatric surgery.

Conclusion

These results have suggested that CT is positively correlated with BMI and decreased with a reduction in BMI progressively. Nutritional disorders resulting from malabsorption have not caused any nutritional optic neuropathy and visual field defect for at least the first postoperative year after bariatric surgery.

Ocular Findings Among Patients With Vitamin D Deficiency

Objective The aim of this study was to evaluate the ocular findings in patients with low vitamin D levels. Methods All patients who attended the Internal Medicine Clinic between March 2018 and February 2020 with vitamin low D levels but had been untreated for the same were included in our study. The exclusion criteria were as follows:history of intraocular surgery, trauma, steroid use, secondary glaucoma, and history of rheumatologic diseases. The patients were classified into three groups: group 1 had severe deficiency with vitamin D levels below 10 µg/L; group 2 had vitamin deficiency with levels of 10-20 µg/L; and group 3 had vitamin D insufficiency with levels of 20-30 µg/L. A comparison among groups was performed in terms of intraocular pressure (IOP), retinal nerve fiber layer (RNFL) thickness, central macular thickness (CMT), dry eyes, cataract, glaucoma, macular degeneration, and refractive error. The evaluation of statistical data was performed with the SPSS Statistics software version 22 (IBM, Armonk, NY). Results There were a total of 98 patients and 196 eyes, who were classified into three groups. There were 41 patients in group 1, 45 in group 2, and 12 in group 3. Groups were similar in terms of age (p=0.25) and gender (p=0.46). The average age among the cohort was 51 ± 13.08 years; 65 (66.3%) of the patients were female and 33 (33.7%) were male. There was no statistically significant difference in terms of IOP (p=0.55), dry eyes (p=0.35), cataract (p=0.22), glaucoma (p=0.50), macular degeneration (p=0.64), and refractive error (p=0.46) among the groups. There was a statistically significant difference in CMT between group 1 and other groups (p=0.002 and p=0.002, respectively). Also, there was a statistically significant difference in RNFL thickness between group 1 and group 2 (p=0.01). When compared in terms of quadrants, a significant difference was found only with regard to the nasal quadrant. Conclusion Based on our findings, lower levels of 25-hydroxyvitamin D might be related to thinning in CMT. Regarding RNFL thickness, while there was a significant difference between groups 1 and 2, there was no difference between groups 1 and 3, and hence the association between lower levels of 25-hydroxyvitamin D and thinning in RNFL thickness could not be clearly established. Hence, we have assumed that lower levels of 25-hydroxyvitamin D might cause thinning in the macula and nasal quadrant of RNFL, and vitamin D deficiency might affect the nasal quadrant of RNFL primarily. Further long-term studies with a larger number of patients might clarify the relationship between vitamin D deficiency and the thinning in CMT, RNFL quadrants, and RNFL thickness.

Neural Network-Based Retinal Nerve Fiber Layer Profile Compensation for Glaucoma Diagnosis in Myopia: Model Development and Validation

Background

Due to the axial elongation–associated changes in the optic nerve and retina in high myopia, traditional methods like optic disc evaluation and visual field are not able to correctly differentiate glaucomatous lesions. It has been clinically challenging to detect glaucoma in highly myopic eyes.

Objective

This study aimed to develop a neural network to adjust for the dependence of the peripapillary retinal nerve fiber layer (RNFL) thickness (RNFLT) profile on age, gender, and ocular biometric parameters and to evaluate the network’s performance for glaucoma diagnosis, especially in high myopia.

Methods

RNFLT with 768 points on the circumferential 3.4-mm scan was measured using spectral-domain optical coherence tomography. A fully connected network and a radial basis function network were trained for vertical (scaling) and horizontal (shift) transformation of the RNFLT profile with adjustment for age, axial length (AL), disc-fovea angle, and distance in a test group of 2223 nonglaucomatous eyes. The performance of RNFLT compensation was evaluated in an independent group of 254 glaucoma patients and 254 nonglaucomatous participants.

Results

By applying the RNFL compensation algorithm, the area under the receiver operating characteristic curve for detecting glaucoma increased from 0.70 to 0.84, from 0.75 to 0.89, from 0.77 to 0.89, and from 0.78 to 0.87 for eyes in the highest 10% percentile subgroup of the AL distribution (mean 26.0, SD 0.9 mm), highest 20% percentile subgroup of the AL distribution (mean 25.3, SD 1.0 mm), highest 30% percentile subgroup of the AL distribution (mean 24.9, SD 1.0 mm), and any AL (mean 23.5, SD 1.2 mm), respectively, in comparison with unadjusted RNFLT. The difference between uncompensated and compensated RNFLT values increased with longer axial length, with enlargement of 19.8%, 18.9%, 16.2%, and 11.3% in the highest 10% percentile subgroup, highest 20% percentile subgroup, highest 30% percentile subgroup, and all eyes, respectively.

Conclusions

In a population-based study sample, an algorithm-based adjustment for age, gender, and ocular biometric parameters improved the diagnostic precision of the RNFLT profile for glaucoma detection particularly in myopic and highly myopic eyes.

Optical coherence tomography measurements in patients with systemic hypertension

AIM

To evaluate the effect of systemic arterial hypertension (SAH) on retinal optical coherence tomography (OCT) parameters and investigate whether a correlation exists between ambulatory blood pressure monitoring (ABPM) and OCT measurements.Material-methods: 115 SAH patients (225 eyes) and 123 healthy control cases (234 eyes) were included. ABPM was performed on 89 of 115 SAH patients. All patients underwent detailed ophthalmologic examination including imaging with OCT. SAH patients were divided into two groups (dippers, non-dippers) according to their nocturnal blood pressure (BP) reduction, and OCT measurements were compared.

RESULTS

Average and superior retinal nerve fiber layer (RNFL) quadrants were significantly thin in hypertensive cases (p:0.002, p < 0.001, respectively). Cup area, cup/disk (c/d) area, and c/d horizontal ratios were wider; the rim area was smaller in hypertensive cases (respectively: p:0.024, p:0.017, p:0.003, p < 0.001). Total macular volume (TMV), the thicknesses in 1-3 and 1-6 mm of the macula were less in hypertensives (p < 0.001). There was no significant difference between dippers and non-dippers in RNFL thickness, macula and optic nerve head (ONH) parameters.

CONCLUSION

There were statistically significant differences between healthy cases and patients with SAH in terms of RNFL, macula thicknesses and ONH parameters.

An Analysis of Retinal Nerve Fiber Layer Thickness before and after Pituitary Adenoma Surgery and its Correlation with Visual Acuity

Introduction

Pituitary adenomas comprise approximately 10% of all intracranial tumors. Initially, subtle changes occur in the field of vision, which are difficult to assess clinically. It has been seen that following surgery of pituitary macroadenoma, total recovery of normal vision occurs in 35% of the patients, improvement of vision occurs in 60%, and in the rest there is no change in vision. Retinal nerve fiber layer thickness (RNFLT) undergoes retrograde degeneration following compression of optic apparatus by pituitary tumor. We planned a study to evaluate RNFLT before and after pituitary adenoma surgery and its correlation with visual acuity.

Material and Methods

Twenty patients (40 eyes) with diagnosed pituitary adenoma were included in the study. Preoperative visual acuity, fundus and RNFL thickness were calculated using spectral-domain OCT Optovue, Heidelberg Engineering, Heidelberg, Germany (RT 100 version 5.1), and postoperative measurement was done after 1 and 3 months. Four-quadrant mean of RNFLT was calculated. Results were tabulated and analyzed.

Statistical Analysis

Results of the study were analyzed using IBM SPSS Statistics version 19.0.

Results

There was no significant change in RNFLT after pituitary adenoma surgery, and it was found that patients with RNFLT within normal range preoperatively showed improvement in visual acuity after pituitary surgery. On the other hand, patients who had thinned-out RNFLT preoperatively showed no improvement in visual acuity. It was also found that once optic disc pallor sets due to chronic compression, then chances of its reversion to normal depend on its grading: only mild pallor disc has some chance to revert to normal, whereas moderate and severe pallor do not revert to normal.

Conclusion

RNFLT and optic disc can be used as prognostic factors for evaluation of visual outcome in pituitary adenoma surgery.

The Relationship Between Retinal Nerve Fiber Layer Thickness and Clinical Symptoms of Alzheimer's Disease

Background/Aim: Retinal nerve fiber layer (RNFL) thickness (RT), which can reflect the status of the retinal optic nerve cells, may be affected in patients with Alzheimer's disease (AD). There are few studies on the correlation of RT of patients with AD (AD-RT) with clinical symptoms of various cognitive domains, neuropsychiatric symptoms, and activities of daily living (ADL). This study is to investigate the relationships between RT and the abovementioned clinical symptoms of AD.

Methods: A total of 96 patients with AD were included in this study. RT was measured in these patients using optical coherence tomography (OCT). Demographic variables, RT, and clinical symptoms were compared between the normal and the abnormal AD-RT groups. Clinical symptoms, including cognitive symptoms, neuropsychiatric symptoms, and ADL, were evaluated using a series of rating scales.

Results: The relationships between RT and cognitive symptoms scores were analyzed in patients with AD. Reduced RT was found in 54.4% of patients with AD. The average RT, RT of the superior 1/2 quadrant, and RT of the inferior 1/2 quadrant of both eyes were all significantly decreased in the abnormal AD-RT group (p < 0.001). Overall cognitive function and performance in multiple cognitive domains, including memory, language, attention, and executive function, were also significantly impaired in the abnormal AD-RT group (p < 0.05). For lower RT value, the global cognitive function and the performance in multiple cognitive domains were worse. ADL was significantly compromised in patients with AD having lower RT values (p < 0.05).

Conclusions: Lower RT value appear to be correlated with cognitive impairment, and RT may be an indicator of cognitive decline in patients with AD. Further studies are required to confirm our findings.

Choroidal Thickness Evaluation in a Transfusion-Dependent Beta-Thalassemia Greek Population

Purpose

To evaluate choroidal thickness in a group of beta-thalassemia patients as assessed by enhanced depth imaging optical coherence tomography.

Patients and Methods

This single-center, observational study involved transfusion-dependent beta-thalassemia (TD-β-thal) patients and healthy controls. One eye of each participant was included in the study. Submacular and peripapillary choroidal thickness, as well as central macular thickness and retinal nerve fiber layer thickness, were evaluated.

Results

Thirty-eight TD-β-thal patients (mean age 42 ± 10.7 years) and 22 healthy controls (mean age 40.3 ± 10.2 years) were included in the study. Subfoveal choroidal thickness was 297.4 ± 74.5 μm in the patient group and 358.4 ± 71.4 μm in the control group (p=0.003). Overall, in the submacular area, the choroid was found to be significantly thinner in the beta-thalassemia population compared to controls in all evaluated points, except for the spot located 1500 μm nasally to the fovea (p=0.093). In the peripapillary area, choroidal thickness was also significantly lower in the thalassemic population compared to the controls (nasal p=0.033, temporal p=0.01, superior p=0.01), except for the inferior quadrant (p= 0.191). We did not observe statistically significant differences in the retinal nerve fiber layer thickness and the central macular thickness between the two groups (p=0.658 and p=0.276, respectively). No correlations with hemoglobin, serum ferritin or iron levels emerged. Patients with the intermediate subtype appeared to have significantly thinner choroids than the ones with thalassemia major.

Conclusion

Our findings suggest that choroidal thickness in the submacular and peripapillary area is significantly reduced in thalassemic patients, compared to healthy individuals. Choroidal thinning in beta-thalassemia possibly reflects the effect of chronic anemia and underlying hemodynamic changes on choroidal tissue.

Diagnostic ability of spectral-domain optical coherence tomography peripapillary retinal nerve fiber layer thickness to discriminate glaucoma patients from controls in an elderly population (The MONTRACHET study)

PURPOSE

To evaluate the capacity of retinal nerve fibre layer (RNFL) thickness measured by SD-OCT to discriminate glaucoma patients from controls in an elderly population.

METHODS

The MONTRACHET (Maculopathy, Optic Nerve, nuTRition, neurovAsCular and HEarT diseases) Study is a population-based study including participants aged 75 years and over. All participants underwent a complete eye examination with optic nerve photographs, visual field testing and OCT peripapillary RNFL thickness measurement. Glaucoma was defined according to the ISGEO (International Society for Epidemiologic and Geographical Ophthalmology) classification. Performance indicators were calculated including area under the receiver operating characteristics curves (AUC), likelihood ratios (LR) and diagnostic odds ratios (DOR).

RESULTS

In total, 1061 participants were included in the study, of whom 89 were classified as having glaucoma and 972 were classified as normal. The mean (SD) age of the population was 82.3 (3.7) years. The average RNFL thickness was significantly lower in the glaucoma group than in controls 64.0 (14.9) µm versus 88.9 (12.4) µm, respectively, p < 0.001) and in all sectors compared with controls. The average RNFL thickness had the highest AUC (0.901) followed by the temporal-inferior (0.879) and temporal-superior sectors (0.862). When RNFL thickness was classified as abnormal by SD-OCT, the average RNFL thickness had the best sensitivity (83.75%) followed by the temporal-inferior sector (75.64%). The specificity for these two parameters was 87.34% and 91.08%, respectively. The highest DOR was 28.70 for average RNFL thickness and reached 34.84 when using the reference database of the OCT manufacturer.

CONCLUSION

This study confirms that SD-OCT could be useful as an additional test to discriminate glaucoma patients from controls in an elderly population.

Infliximab therapy provides beneficial effects for choroidal thickness increase in patients with active ankylosing spondylitis: A possible mechanism mediating the suppressing of uveitis attacks

Objectives

This study aims to quantitatively assess the profile of the choroidal thickness (ChT) in patients with ankylosing spondylitis (AS) using optical coherence tomography (OCT), and to examine whether the posterior eye segment abnormalities in active AS patients are reversible by infliximab therapy.

Patients and methods

October 2014 and March 2016 Thirty-one patients with AS (22 males, 9 females; mean age 39.6±12.3 years; range, 22 to 68 years) and 24 healthy controls (16 males, 8 females; mean age 40.8±8.9 years; range, 35 to 61 years) were enrolled. Patients' clinical and demographic characteristics were recorded. Using OCT, we performed retinal nerve fiber layer (RNFL) thickness, ganglion cell complex, and ChT measurements in AS patients before and six months after the initiation of infliximab therapy, and in healthy controls.

Results

At baseline, patients with AS had higher ChT (mean±standard deviation: 347.5±114.4 μm) compared to healthy controls (322.1±62.8 μm), although this did not reach statistical significance level (p=0.283). At six months after the first measurement, the mean ChT was significantly decreased (under infliximab therapy: 326.5±99.7 μm vs. before: 347.5±114.4 μm, p=0.018) in AS group, while no significant change was observed in the control group (p=0.102). RNFL thickness in the AS group was significantly decreased after six months of treatment with infliximab (p=0.008).

Conclusion

By evaluating the posterior eye segment of patients with AS using OCT, this study has demonstrated that active AS patients had higher ChT. The significant reduction in this ChT after infliximab therapy may be mediating the established effective suppressing action of infliximab on uveitis attacks.

Norms of Interocular Circumpapillary Retinal Nerve Fiber Layer Thickness Differences at 768 Retinal Locations

Purpose

The onset and progression of optic neuropathies like glaucoma often occurs asymmetrically between the two eyes of a patient. Interocular circumpapillary retinal nerve fiber layer thickness (cpRNFLT) differences could detect disease earlier. To apply such differences diagnostically, detailed location specific norms are necessary.

Methods

Spectral-domain optical coherence tomography cpRNFLT circle scans from the population-based Leipzig Research Centre for Civilization Diseases-Adult study were selected. At each of the 768 radial scanning locations, normative interocular cpRNFLT difference distributions were calculated based on age and interocular radius difference.

Results

A total of 8966 cpRNFLT scans of healthy eyes (4483 patients; 55% female; age range, 20-79 years) were selected. Global cpRNFLT average was 1.53 µm thicker in right eyes (P < 2.2 × 10-16). On 96% of the 768 locations, left minus right eye differences were significant (P < 0.05), varying between +11.6 µm (superonasal location) and -11.8 µm (nasal location). Increased age and difference in interocular scanning radii were associated with an increased mean and variance of interocular cpRNFLT difference at most retinal locations, apart from the area temporal to the inferior RNF bundle where cpRNFLT becomes more similar between eyes with age.

Conclusions

We provide pointwise normative distributions of interocular cpRNFLT differences at an unprecedentedly high spatial resolution of 768 A-scans and reveal considerable location specific asymmetries as well as their associations with age and scanning radius differences between eyes.

Translational Relevance

To facilitate clinical application, we implement these age- and radius-specific norms across all 768 locations in an open-source software to generate patient-specific normative color plots.

Retinal Nerve Fibre Layer Thickness Change After CO2 Laser-Assisted Deep Sclerectomy Surgery

Purpose

The goal of our study was to investigate changes in intraocular pressure (IOP), best-corrected visual acuity (BCVA), and retinal nerve fibre layer thickness (RNFLT) after CO2 laser-assisted deep sclerectomy (CLASS).

Methods

We carried out uncomplicated CLASS surgeries and a 12-month follow-up on 22 open-angle glaucomatous (OAG) eyes of 22 patients. IOP, BCVA, and RNFLT with spectral-domain optical coherence tomography (SD OCT) were recorded before and 1, 3, 6, 12 months after surgery.

Results

Mean age of patients was 68.1 years. IOP decreased from preoperative 28.45±5.99 SD mmHg (mean±standard deviation) to 15.09±2.40 mmHg (p=0.00039) at 12 months after surgery. BCVA-change from preoperative 0.34±0.38 SD (LogMAR) to 0.37±0.41 SD (LogMAR) was not significant (p=0.2456). RNFLT-change from preoperative 60.50±18.15µm to 59.63±17.52 µm at 12 months postoperatively was not significant (p=0.056). Qualified success rate of CLASS surgery was 72.7%, whereas complete success rate was 64% at 1 year postoperatively.

Conclusion

Successful CLASS surgery efficiently reduced IOP. At postoperative 12 months, RNFLT and BCVA were not reduced significantly. There was no significant glaucomatous progression after surgery encountered in respect of investigated parameters.

Evaluation of retinal nerve fiber layer thickness and optic nerve functions in fellow eye of neuromyelitis optica with unilateral optic neuritis

Purpose

Peripapillary retinal nerve fibre layer (RNFL) thickness might be useful in monitoring ongoing subclinical structural damage especially in eyes with no history of optic neuritis (ON) in neuromyelitis optica (NMO).

Objective

To evaluate the peripapillary RNFL thickness and optic nerve functions in fellow eye of NMO with unilateral optic neuritis.

Materials and Methods

A comparative cross-sectional study was conducted in 2 tertiary hospitals from August 2017 to May 2019. RNFL thickness and optic nerve functions were evaluated. Statistical analysis was performed using Statistical Package for Social Science version 24.

Results

A total of 26 NMO patients and 26 controls were involved in this study. The median age (IQR) of NMO patients was 32.5 (12) years old. The RNFL thickness was significantly reduced in NMO patients with non-ON eyes as compared to control group. Best corrected visual acuity between the 2 groups were comparable (0.20 vs 0.00, p=0.071). Contrast sensitivity was also reduced in NMO patients (non-ON eyes) at all 5 spatial frequencies. In NMO group, 34.6% have normal colour vision. The mean deviation (MD) of Humphrey visual field (HVF) was higher in NMO group (p<0.001). There was a moderate correlation between RNFL thickness and contrast sensitivity. Weak correlation was found between the RNFL thickness with visual acuity and mean deviation of visual field test.

Conclusion

Our study showed that the fellow eye of NMO patients with unilateral ON revealed a significant reduction in RNFL thickness and all the optic nerve functions have subtle early changes that signify a subclinical retinal damage.

Peripapillary choroidal thickness in patients with vitamin D deficiency

AIM

To investigate the effects of vitamin D deficiency on peripapillary choroidal thickness and retinal nerve fiber layer thickness.

MATERIALS AND METHODS

Patients diagnosed with vitamin D deficiency but not yet treated for it (Group 1) and patients with normal vitamin D levels (Group 2) were included in this study. Subjects with any kind of eye disease and/or systemic disease were excluded from this study. Demographic characteristics of the patients were collected, and the subfoveal choroidal thickness, central foveal thickness, retinal nerve fiber layer thickness, and peripapillary choroidal thickness were measured using optical coherence tomography.

RESULTS

The mean ages in Groups 1 and 2 were 30.5 ± 6.7 and 28 ± 5.78 years (p = 0.12), respectively, and female to male ratios were 19/11 and 17/13, respectively (p = 0.59). The mean vitamin D levels were 8.2 ± 2.5 and 28 ± 4.9 ng/mL in Groups 1 and 2, respectively (p <0.001). In Group 1, subfoveal choroidal thickness and nasal and inferior peripapillary choroidal thicknesses at 500 µm were 327.5 ± 81.4, 142.9 ± 40, and 140.66 ± 38.74 µm, respectively. For Group 2, these values were 407.1 ± 85.5, 189.3 0 ± 57.18, and 195.93 ± 67.58 µm, respectively (p <0.001, p = 0.001, and p <0.001, respectively). In addition, a positive correlation was found between vitamin D levels and the subfoveal choroidal thickness and nasal and inferior peripapillary choroidal thicknesses in all patients (r = 0.365, p = 0.005; r = 0.341, p = 0.008; and r = 0.370, p = 0.004, respectively).

CONCLUSION

Subfoveal choroidal thickness and inferior and nasal peripapillary choroidal thicknesses decreased in patients with vitamin D deficiency.

Retinal Nerve Fiber Layer Thickness and Total Macular Volume in Multiple Sclerosis Subtypes and Their Relationship with Severity of Disease, a Cross-Sectional Study

Background

Optic neuritis (ON) is an inflammatory demyelinating lesion in the optic nerve, which is strongly associated with multiple sclerosis (MS). Optical coherence tomography (OCT) is a noninvasive technique for the evaluation of the retinal layers. Our aim was to examine OCT metrics including retinal nerve fiber layer thickness (RNFLT), and total macular volume (TMV), in MS subtypes and their relationship with duration, first manifestation, and severity of disease.

Material and Methods

In this cross-sectional study, patients with a definite diagnosis of MS underwent complete ophthalmic and neurologic examination. OCT parameters including TMV and RNFLT were compared between MS subtypes and different first manifestations of MS. Their relationships were also studied with the duration and severity of disease based on the Expanded Disability Status Scale (EDSS) score.

Results

A total of 240 eyes were examined in 120 enrolled MS patients. The differences in RNFLT were not analytically meaningful between the subtypes of MS, but the differences in TMV values were statistically significant between the subtypes of MS (P: 0.39 and P: 0.04, respectively). The differences between RNFLT and TMV of eyes with and without ON were statistically significant between these two groups (P<0.001 and P<0.001). There was also an inverse correlation between EDSS disability score and RNFLT and TMV values (P: 0.00, r: −0.33 and P: 0.034, r: −0.11, respectively) and a significant inverse correlation between the duration of MS and RNFLT (P: 0.00, r: −0.47). The differences in RNFLT and TMV values were analytically meaningful between the categories of first manifestations of MS (P: 0.000 and P: 0.027, respectively).

Conclusion

RNFLT and TMV represent noninvasive parameters for assessment of neuroaxonal degeneration in the anterior visual pathway that correlate with the severity and duration of multiple sclerosis. The lowest RNFLT and TMV values were also seen in the perceptual category between the first manifestations of MS. Therefore, they may be useful in the evaluation of MS patients.

A Meta-analysis of Retinal Cytoarchitectural Abnormalities in Schizophrenia and Bipolar Disorder

BACKGROUND

Schizophrenia (SZ) and bipolar disorder (BD) are characterized by reductions in gray matter and white matter. Limitations in brain imaging have led researchers to use optical coherence tomography (OCT) to explore retinal imaging biomarkers of brain pathology. We examine the retinal layers that may be associated with SZ or BD.

METHODS

Articles identified using PubMed, Web of Science, Cochrane Database. Twelve studies met inclusion for acutely/chronically ill patients. We used fixed or random effects meta-analysis for probands (SZ and BD), SZ or BD eyes vs healthy control (HC) eyes. We adjusted for sources of bias, cross-validated results, and report standardized mean differences (SMD). Statistical analysis performed using meta package in R.

RESULTS

Data from 820 proband eyes (SZ = 541, BD = 279) and 904 HC eyes were suitable for meta-analysis. The peripapillary retinal nerve fiber layer (RNFL) showed significant thinning in SZ and BD eyes compared to HC eyes (n = 12, SMD = -0.74, -0.51, -1.06, respectively). RNFL thinning was greatest in the nasal, temporal, and superior regions. The combined peripapillary ganglion cell layer and inner plexiform layer (GCL-IPL) showed significant thinning in SZ and BD eyes compared to HC eyes (n = 4, SMD = -0.39, -0.44, -0.28, respectively). No statistically significant differences were identified in other retinal or choroidal regions. Clinical variables were unrelated to the RNFL or GCL-IPL thickness by meta-regression.

CONCLUSION

The observed retinal layer thinning is consistent with the classic gray- and white-matter atrophy observed on neuroimaging in SZ and BD patients. OCT may be a useful biomarker tool in studying the neurobiology of psychosis.

A meta-analysis to study the effect of pan retinal photocoagulation on retinal nerve fiber layer thickness in diabetic retinopathy patients

Background. Diabetic retinopathy is a microvascular disease, it is associated with changes in peripapillary retinal nerve fiber layer thickness, these changes being more pronounced in PDR (Proliferative diabetic retinopathy) patients undergoing laser photocoagulation. Objective. To assess changes in peripapillary retinal nerve fiber layer thickness in proliferative diabetic retinopathy patients using optical coherence tomogram (OCT). Methods. The database search was conducted in June 2018 and continued until October 2018. The search engines used included Pubmed, Medline, OVID and Google Scholar. A meta-analysis of weighted mean difference and standard deviation was conducted. Results. A total of 10 studies containing 377 eyes of PDR patients were selected. The analysis of the included studies revealed no significant effect of PRP on average retinal nerve fiber layer thickness (0.249, 95% CI: -0.985 to 1.483) using OCT. Conclusion. Hence, to conclude, our meta-analysis revealed that there was no significant effect of PRP on RNFL thickness and the impact of PRP could vary. Measurement of peripapillary RNFL thickness may yield erroneous and unpredictable results in this subgroup of patients, further confounding the evaluation of nerve fiber layer damage and its progression.

Optical coherence tomography and neurodegeneration in epilepsy

PURPOSE

To compare optical coherence tomography measurements; central macular thickness, ganglion cell complex, and retinal nerve fiber layer thickness in patients with epilepsy versus healthy controls.

METHODS

We evaluated 28 eyes of 28 patients with epilepsy and 34 eyes of 34 healthy subjects. Central macular thickness, ganglion cell complex, and retinal nerve fiber layer thickness measurements were performed by spectral-domain optical coherence tomography.

RESULTS

Superior and superotemporal quadrant ganglion cell complex, average, and superior quadrant retinal nerve fiber layer thickness measurements were significantly lower in epilepsy group compared to healthy control subjects. Central macular thickness was significantly lower in polytherapy group compared to monotherapy group. Ganglion cell complex and retinal nerve fiber layer thickness measurements were not significantly different between polytherapy and monotherapy groups.

CONCLUSION

The present study shows that epileptic patients taking antiepileptic drugs have reduced ganglion cell complex and retinal nerve fiber layer thickness compared to healthy controls. This can be related to the epileptic process in the brain. Optical coherence tomography may be a useful tool for showing the neurodegeneration in patients with epilepsy.

Effect of Trabeculectomy on OCT Measurements of the Optic Nerve Head Neuroretinal Rim Tissue

Purpose

Ophthalmologists commonly perform glaucoma surgery to treat progressive glaucoma. Few studies have examined the stability of OCT neuroretinal rim parameters after glaucoma surgery for ongoing detection of glaucoma progression.

Design

Longitudinal cohort study.

Participants

20 eyes (16 subjects) with primary open angle glaucoma who had undergone a trabeculectomy.

Methods

We calculated the change in OCT parameters (minimum rim area (MRA), minimum rim width (MRW), Bruch's membrane opening (BMO) area, mean cup depth (MCD), anterior lamina cribrosa surface depth (ALCSD), prelaminar tissue thickness (PLTT), retinal nerve fiber layer thickness (RFNLT) during an interval from the visit before the surgery to the visit after the surgery, a span of approximately 6-months. We also calculated changes in the same eyes over two separate 6-month intervals that did not contain trabeculectomy to serve as control. We compared these intervals using a generalized linear model (with compound symmetry correlation structure), accounting for the correlation between time intervals for the same eye.

Main outcomes measures

MRW, MRA, angle above the reference plane for MRW and MRA, BMO area, MCD, mean ALCSD, PLTT, RNFLT and visual field parameters (mean deviation (MD), pattern standard deviation (PSD), and visual field index (VFI)).

Results

The intervals containing trabeculectomy showed a significant decrease in intraocular pressure (-9.2 mmHg, p<.001) when compared to control intervals. Likewise, the following neuroretinal rim parameters showed significant changes with trabeculectomy: increased MRW (+6.04μm, p=.001), increased MRA (+0.014mm², p=.024), increased angle above reference plane of MRW (+2.64°, p<.001), decreased MCD (-11.6μm, p=.007), and decreased mean ALCSD (-18.91μm, p=.006). This is consistent with an increase in rim tissue thickness and a more anterior position of the ILM and ALCS relative to the BMO plane. Conversely, RNFLT change was not significantly different between trabeculectomy and control intervals (p=.37).

Conclusion

Trabeculectomy resulted in anatomical changes to the ONH rim associated with reduced glaucomatous cupping. The RNFL thickness may be a more stable measure of disease progression that clinicians can use to monitor across time intervals containing glaucoma surgery.

Clinical Observation of Patients with Leber's Hereditary Optic Neuropathy Before Gene Therapy

BACKGROUND

Leber's hereditary optic neuropathy is a hereditary mitochondrial disease. No effective treatment has so far been established, with gene therapy currently being the most promising. Because of the possibility of spontaneous visual acuity recovery in this disease, we screened patients before gene therapy, excluding those with spontaneous visual acuity improvement, and prepared for the subsequent gene therapy.

OBJECTIVE

To clinically observe the course of Leber's hereditary optic neuropathy for 6 months prior to gene therapy.

METHODS

Sixty-six patients with Leber's hereditary optic neuropathy were enrolled in the study. Patients were classified based on the duration of disease: less than 24 months and over 24 months. Three clinical follow-up examinations were conducted over 1 year. We assessed intraocular pressure, visual acuity, visual field, retinal nerve fiber layer thickness, fundus photographs, and visual evoked potential.

RESULTS

Eighty-two eyes displayed stable visual acuity, including both eyes in 34 patients and one eye in 14 patients; 33 eyes of 22 patients displayed decrease in visual acuity (less than 24 months: 24 eyes; over 24 months: nine eyes); and 17 eyes of 12 patients showed improvement in visual acuity (less than 24 months: four eyes; over 24 months: 13 eyes). Visual acuity and visual field indices decreased over 24 months from disease onset and appeared stable after 24 months.

CONCLUSION

Most patients with Leber's hereditary optic neuropathy gradually stabilize visual function with prolonged onset time, and the lower possibility of spontaneous vision recovery provides a basis for future evaluation of the effectiveness of gene therapy.

Comparative Effect of Feeding Human Milk as Opposed to Formula on Visual Function and Ocular Anatomy

Background/Objective: Performance of ocular examinations on children who were breastfed, fed with formula, and combination of the two for the first 6 months of age. Subsequently, refractive errors, allergic conjunctivitis, and retinal nerve fiber layer (RNFL) thickness were evaluated. Materials and Methods: The present study included a total of 242 eyes of 121 children (aged 60-84 months, 65 males, 56 females) admitted to the outpatient clinic of our institution. The patients were divided into three groups according to their feeding pattern during their first 6 months postdelivery: breastfed children (Group 1, n = 40), children fed with a combination of breast and formula milk (Group 2, n = 41), and children exclusively fed with formula-milk (Group 3, n = 40). All patients underwent detailed ophthalmologic examinations, and measurements of the RNFLs were recorded. Results: No significant difference was observed between the groups in terms of refractive error. In Group 3, we found that allergic conjunctivitis was significantly higher than in the other groups. In addition, in Group 3, the thickness of the RNFL was found to be significantly higher in the superior quadrants of both the eyes of children than in Groups 1 and 2 (p < 0.05). Conclusions: We found that the type of feeding experienced by infants in their first 6 months has no effect on refractive error but has significant effects on both allergic conjunctivitis and RNFL. To determine the cause of this difference in the RNFL and to further validate the present study, future studies with larger patient groups and animal experiments are needed.

Retinal Morphometric Markers of Crystallized and Fluid Intelligence Among Adults With Overweight and Obesity

Objective: To investigate the relationship between retinal morphometric measures and intellectual abilities among adults with overweight and obesity. Methods: Adults between 25 and 45 years (N = 55, 38 females) with overweight or obesity (BMI ≥ 25.0 kg/m2) underwent an optical coherence tomography (OCT) scan to assess retinal nerve fiber layer (RNFL) volume, ganglion cell layer (GCL) volume, macular volume, and central foveal thickness. Dual-Energy X-ray absorptiometry was used to assess whole-body adiposity (% Fat). The Kaufman Brief Intelligence Test-2 was used to assess general intelligence (IQ), fluid, and crystallized intelligence. Hierarchical linear regression analyses were performed to examine relationships between adiposity and intelligence measures following adjustment of relevant demographic characteristics and degree of adiposity (i.e., % Fat). Results: Although initial bivariate correlations indicated that % Fat was inversely related to fluid intelligence, this relationship was mitigated by inclusion of other demographic factors, including age, sex, and education level. Regression analyses for primary outcomes revealed that RNFL was positively related to IQ and fluid intelligence. However, only GCL was positively related to crystallized intelligence. Conclusion: This work provides novel data linking specific retinal morphometric measures - assessed using OCT - to intellectual abilities among adults with overweight and obesity. Clinical Trial Registration: www.clinicaltrials.gov, identifier NCT02740439.

Evaluation of macular ganglion cell analysis compared to retinal nerve fiber layer thickness for preperimetric glaucoma diagnosis

Purpose:

To compare the diagnostic ability of the ganglion cell analysis (GCA) and retinal nerve fiber layer (RNFL) protocol on optical coherence tomography (OCT), to diagnose preperimetric glaucoma.

Methods:

A prospective, cross-sectional study of 275 adult patients including 47 early glaucoma (mean deviation better than -6.0 D), 150 glaucoma suspects (106 with suspicious discs and 44 ocular hypertensive (OHT), and 78 normal controls was done. Eligible participants were scanned with the spectral domain Cirrus™ OCT (Carl Zeiss Meditec, Dublin, CA). Average peripapillary RNFL thickness and GCA measurements were obtained. Area under receiver operating characteristic (AROC) curves were used to evaluate discriminant value of both protocols to diagnose likely preperimetric glaucoma among glaucoma suspects.

Results:

Average RNFL and GCA were significantly thinner in glaucoma patients compared to glaucoma suspects and normal controls (P < 0.001). The RNFL was 92.26 ± 8.8 μ in normal controls, 87.9 ± 12.12 μ in glaucoma suspects and significantly thinner in POAG (70.29 ± 10.18 μ; P < 0.001). The GCA was 81.94 ± 6.17 μ in normal controls, 77.69 ± 9.03 μ in glaucoma suspects, and significantly thinner in POAG (69.36 ± 11.06 μ; P < 0.001). AROCs for discriminating glaucoma suspects from normal were modest, with no difference in AROC of average RNFL or GCA measurements (DeLong; P = 0.93). Average RNFL thickness had significantly greater AROC values than average GCA for discriminating glaucoma suspects (both suspicious discs and OHT) from glaucoma (P = 0.03 and 0.05, respectively. AROC for diagnosing glaucoma was significantly better (P = 0.02) for RNFL (0.88 ± 0.03) than GCA (0.77 ± 0.04).

Conclusion:

In the present time, GCA measurements, as provided by the SD-OCT, do not appear to outperform RNFL measurements in the diagnosis of preperimetric glaucoma.

Peripapillary choroidal thickness in untreated normal-tension glaucoma eyes with a single-hemifield retinal nerve fiber layer defect

The aim of this study was to evaluate the regional variations of peripapillary choroidal thickness (PCT) in normal-tension glaucoma (NTG) patients with a retinal nerve fiber layer (RNFL) defect localized to a single superior or inferior hemifield. This is a retrospective, cross-sectional study.Ninety-five NTG patients and 53 normal subjects were divided into 3 groups: 34 eyes with a superior RNFL defect (group A), 61 eyes with an inferior RNFL defect (group B), and 53 normal eyes (group C). The average, quadrant, and clock-hour RNFL thickness (RNFLT) and PCT were measured using spectral-domain optical coherence tomography. Choroidal thickness ratio (CTR) was defined as the ratio of the measured PCT at a quadrant or a clock-hour position to the average PCT of an individual. The PCT, CTR, and RNFLT were compared among 3 groups.The average PCT of NTG patients was thinner compared to that of healthy subjects (154.17 vs. 180.65 μm, P < .001). Although the average, quadrant, and clock-hour PCTs were not different between groups A and B, the CTR at 11 o'clock was significantly lower in group A compared to that of group B. The 11 o'clock CTR was an independent factor for the initial location of a RNFL defect (P = .03).Eyes with NTG showed regional differences in CTR according to the hemisphere location of their initial RNFL damage. Therefore, CTR may be more useful than the absolute PCT value to assess regional PCT differences in eyes with NTG.