Photoreceptor integrity and visual acuity in cystoid macular oedema associated with retinitis pigmentosa

Central Serous Chorioretinopathy: An Update on the Current State of Management

Central serous chorioretinopathy (CSCR) is a relatively common retinal disorder that leads to central vision impairment, often with a high recurrence rate. The exact etiology and pathogenetic mechanisms have not been fully elucidated but are likely to be associated with hyperpermeability of the choroidal capillaries and failure of the retinal pigment epithelium (RPE), leading to serous detachment of the neurosensory retina. Multimodal imaging plays a critical role in the diagnostic approach and monitoring of CSCR. Fortunately, the natural course of the disease is usually self-limiting, with spontaneous resolution and total fluid reabsorption. However, some patients may exhibit recurrences or persistent subretinal fluid (chronic CSCR), leading to progressive and irreversible RPE atrophy or photoreceptor damage. Thus, to prevent permanent visual loss, individualized treatment should be considered. Recent developments in the diagnostic and therapeutic approach have contributed to better outcomes in patients with CSCR. More studies are required to improve our understanding of epidemiology, pathogenesis, diagnosis, and treatment, with a significant impact on the management of this challenging clinical entity. The purpose of this review is to summarize the current knowledge about the clinical features, diagnostic workup, and therapeutic approach of CSCR.

Characterizing macular edema in retinitis pigmentosa through a combined structural and microvascular optical coherence tomography investigation

The aim of the study was to characterize macular edema (ME) in retinitis pigmentosa (RP) by means of quantitative optical coherence tomography (OCT)-based imaging. The study was designed as observational, prospective case series, with 1-year follow-up. All RP patients underwent complete ophthalmologic assessment, including structural OCT, OCT angiography, and microperimetry (MP). The primary outcome was the characterization through quantitative OCT-based imaging of RP eyes complicated by ME. A total of 68 RP patients' eyes (68 patients) and 68 eyes of 68 healthy controls were recruited. Mean BCVA was 0.14 ± 0.17 LogMAR at baseline and 0.18 ± 0.23 LogMAR at 1-year follow-up (p > 0.05). Thirty-four eyes (17 patients; 25%) showed ME, with a mean ME duration of 8 ± 2 months. Most of the eyes were characterized by recurrent ME. The ME was mainly localized in the inner nuclear layer in all eyes. LogMAR BCVA was similar in all RP eyes, whether with or without ME, although those with ME were associated with higher vessel density values, as well as thicker choroidal layers, than those without ME. In conclusion, the inner retina is closely involved in the pathogenesis of ME. The impairment of retinal-choroidal exchanges and Müller cell disruption might be a major pathogenic factor leading to the onset of ME in RP.

Anatomical and functional correlates of cystic macular edema in retinitis pigmentosa

Cystoid macular edema (CME) is a major cause of central visual deterioration in retinitis pigmentosa. The exact reason for CME and its prognostic significance in this patient population is unknown. We seek to find clues to answer these questions by examining the anatomical correlations between retinal cysts and retinal morphometric parameters in a cohort of patients with retinitis pigmentosa and CME. For this reason, 103 patients (196 eyes) with untreated cystoid macular edema (CME) were identified from a pool of 578 genotyped patients with retinitis pigmentosa. Image analyses were conducted using three central horizontal OCT scans of these patients to calculate cross-sectional areas of the retinal nerve fiber layer, outer retinal, inner retinal, cysts, and total retinal areas. Lengths of the ellipsoid zone and outer limiting membrane were also measured. Best-fit curves were derived for analyzing the factors playing a role in the size of the retinal cysts and the patients’ visual acuity. Generalized Estimating Equation and multivariate linear regression analyses were conducted to determine the correlations between visual acuity, morphometric and clinical data, and the significant cyst size and visual acuity determinants. Twenty-five percent of the screened patients (103/578) had CME. Patients with autosomal dominant retinitis pigmentosa had the highest incidence of CME (43.6%, p<0.001) but also had the best visual acuity (20/34±20/30, p = 0.02). The total cyst area was 0.14±0.18 mm². Outer retinal area (B = 0.214; p = 0.008), age (B = -0.003; p<0.001) and retinal nerve fiber area (B = 0.411; p = 0.005) were main determinants of the (r = 0.44; p<0.001) cyst size. Cysts resolved with progressing retinal degeneration. Length of the intact ellipsoid zone (B = -5.16E-5; p<0.001), the inheritance pattern (B = 0.04; p = 0.028) and retinal nerve fiber area (B = 0.751; p<0.001) were the main determinants of visual acuity. In patients with retinitis pigmentosa and cystoid macular edema, retinal nerve fiber layer thickness is associated with decreasing visual acuity and cyst size. This finding suggests that intraretinal cysts may compress retinal axons and cause subsequent visual loss in retinitis pigmentosa.

Non-vasogenic cystoid maculopathies

Besides cystoid macular edema due to a blood-retinal barrier breakdown, another type of macular cystoid spaces referred to as non-vasogenic cystoid maculopathies (NVCM) may be detected on optical coherence tomography but not on fluorescein angiography. Various causes may disrupt retinal cell cohesion or impair retinal pigment epithelium (RPE) and Müller cell functions in the maintenance of retinal dehydration, resulting in cystoid spaces formation. Tractional causes include vitreomacular traction, epiretinal membranes and myopic foveoschisis. Surgical treatment does not always allow cystoid space resorption. In inherited retinal dystrophies, cystoid spaces may be part of the disease as in X-linked retinoschisis or enhanced S-cone syndrome, or occur occasionally as in bestrophinopathies, retinitis pigmentosa and allied diseases, congenital microphthalmia, choroideremia, gyrate atrophy and Bietti crystalline dystrophy. In macular telangiectasia type 2, cystoid spaces and cavitations do not depend on the fluid leakage from telangiectasia. Various causes affecting RPE function may result in NVCM such as chronic central serous chorioretinopathy and paraneoplastic syndromes. Non-exudative age macular degeneration may also be complicated by intraretinal cystoid spaces in the absence of fluorescein leakage. In these diseases, cystoid spaces occur in a context of retinal cell loss. Various causes of optic atrophy, including open-angle glaucoma, result in microcystoid spaces in the inner nuclear layer due to a retrograde transsynaptic degeneration. Lastly, drug toxicity may also induce cystoid maculopathy. Identifying NVCM on multimodal imaging, including fluorescein angiography if needed, allows guiding the diagnosis of the causative disease and choosing adequate treatment when available.

Prevalence and associated relating factors in patients with hereditary retinal dystrophy: a nationwide population-based study in Taiwan

OBJECTIVE

To investigate the prevalence, incidence and relating factors that are associated with hereditary retinal dystrophy (HRD) in Taiwan from 2000 to 2013.

DESIGN, SETTING AND PARTICIPANTS

This is a nationwide, population-based, retrospective case-control study using National Health Insurance Database. Study groups are patients with HRD as case group; age-matched patients without any diagnosis of HRD as control group. We enrolled 2418 study subjects, of which 403 were HRD patients. Important relating factors such as hypertension, diabetes, coronary artery disease, autoimmune disease, cancer, liver cirrhosis, chronic kidney disease, stroke, hyperlipidaemia, asthma, depression and dementia are also included.

EXPOSURE

Patients diagnosed with HRD were retrieved from National Health Insurance Database.

MAIN OUTCOMES AND MEASURES

OR calculated between the relating factors and HRD for objects and stratified by age and sex group between 2000 and 2013.

RESULTS

Four hundred and three patients were included in the study group and 2015 in the control group. The incidence of HRD was 3.29/100 000, and the prevalence of HRD was 40.5/100 000 persons. The tendency of study group to have more cataract, cystoid macula oedema (CME) as compared with the control group. Among the subgroup with comorbidities, the relating factors such as hypertension, diabetes and chronic kidney disease was significantly higher among HRD patients with age 55 and above.

CONCLUSIONS

74% of the diagnosed HRD are retinitis pigmentosa. Population-based data suggested an increased incidence of cataract in younger patients, whereas older HRD patients are more susceptible to develop CME. Further work is needed to elucidate the mechanism between these ophthalmological disorders and HRD.

Long-term Outcomes of Cataract Surgery in Patients with Retinitis Pigmentosa

PURPOSE

To investigate the long-term outcomes of cataract surgery in patients with retinitis pigmentosa (RP).

DESIGN

Retrospective, observational study.

PARTICIPANTS

Sixty-four patients with typical RP (22 males, 42 females, average age 62.8 ± 10.1 years) who underwent cataract surgery at Kyushu University Hospital between May 2007 and October 2015 and who were followed up for ≥3 years post-surgery.

METHODS

Differences between pre- and post-surgery visual function, including best-corrected visual acuity (BCVA) and parameters in the Humphrey Field Analyzer (HFA) examinations using the central 10-2 program were investigated. The pre-surgery conditions of the foveal ellipsoid zone (EZ) were classified into three grades (grade 1: invisible; grade 2: abnormal; grade 3: normal) based on optical coherence tomography findings.

MAIN OUTCOME MEASURES

BCVA, the retinal sensitivity in HFA 10-2 tests.

RESULTS

Cataract surgery was performed in 96 eyes, with an average follow-up period of 5.8 ± 2.4 years. The mean pre-surgery BCVA was 0.64 ± 0.52 logarithm of the minimum angle of resolution (logMAR), and the final post-surgery BCVA was 0.61 ± 0.67 logMAR (p=0.57). Significant improvement of post-surgery BCVA was observed only in the eyes with preserved foveal EZ (grade 3) (p<0.01). In 62 eyes of the 45 patients who received HFA 10-2 tests, the mean values of deviation, macular sensitivity and foveal sensitivity at the final visit were significantly decreased compared with preoperative values (p<0.01), while those in the grade 3 eyes did not change significantly post-surgery (p=0.13).

CONCLUSIONS

In the long-term course after cataract surgery in RP patients, many cases experienced vision loss with progression of the disease. A preoperative finding of preserved foveal EZ was associated with a better visual prognosis, suggesting that EZ evaluation is useful to predict the long-term visual outcome after cataract surgery in RP patients.

Genetic Profile and Associated Characteristics of 150 Korean Patients with Retinitis Pigmentosa

PURPOSE

Retinitis pigmentosa (RP) shows great diversity between genotypes and phenotypes, and it is important to identify the causative genes. This study aimed to analyze the molecular profiles, associated ocular characteristics, and progression of RP in Korean patients.

METHODS

All the genetic variants in patients with RP, identified using targeted next-generation sequencing (NGS) with a panel of 88 RP-related genes between November 2018 and November 2019, were retrospectively reviewed. All the patients underwent comprehensive ophthalmological evaluations, and their clinical and family histories were recorded. The best-corrected visual acuity (BCVA) deterioration and photoreceptor disruption progression rates were determined based on the major causative mutational genes using nonlinear mixed models, and the differences among them were investigated using the interaction effect.

RESULTS

Among the 144 probands, 82 variants in 24 causative genes were identified in 77 families (53.5%). Most of the RP cases were associated with autosomal recessive variants (N = 64 (44.4%)), followed by autosomal dominant (N = 10 (6.9%)) and X-linked variants (N = 3 (2.1%)). The four most frequently affected genes were EYS (N = 15 (10.4%)), USH2A (N = 12 (8.3%)), PDE6B (N = 9 (6.3%)), and RP1 (N = 8 (5.6%)). Epiretinal membranes and cystoid macular edema were frequently noted in the patients with USH2A (75.0%) and PDE6B (50.0%) variants, respectively. During the follow-up period, the BCVA and photoreceptor disruption changes were significantly different among the patients carrying the four common causative genes (P=0.014 and 0.034, resp.). Patients with PDE6B variants showed faster BCVA changes (0.2 LogMAR/10 years), and those with USH2A variants showed the fastest ellipsoid zone disruptions (-170.4 µm/year).

CONCLUSION

In conclusion, our genetic analysis using targeted NGS provides information about the prevalence of RP-associated mutations in Korean patients. Delineating clinical characteristics according to genetic variations may help clinicians identify subtype features and predict the clinical course of RP.

Detection Sensitivity of Retinitis Pigmentosa Progression Using Static Perimetry and Optical Coherence Tomography

Purpose

To compare the detection sensitivities of the progression of retinitis pigmentosa (RP) by automated perimetry to obtain the mean deviation (MD) and total point score and by optical coherence tomography (OCT) to determine the residual ellipsoid zone (EZ) length and thickness of retinal layers.

Methods

Twenty-two eyes of 22 patients with RP who underwent annual automated perimetry (Humphrey Field Analyzer 10-2) and OCT examinations during the same period more than four times were included. Disease progression was evaluated using linear regression analysis with the least-squares method. The disease progression speed and interinspection fluctuations for the different examinations were compared using standardized values. The progression detection ability factor, defined as the average of the least squares divided by the square of annual change, was used to compare the sensitivities of the examinations for detecting the progression of RP.

Results

EZ length showed a high correlation with MD (R = 0.87; P = 1.12E-07) at baseline. Disease progression was detected more frequently using EZ length (12/22 eyes) than using MD (3/22 eyes; P = 0.004) or central retinal thickness (1/11 eyes; P = 0.012). Linear regression using standardized values showed that the EZ length had the fastest annual change, with the smallest least absolute values. EZ length was more sensitive for detecting RP progression than MD, total point score, visual acuity, or central retinal thickness.

Conclusions

EZ measurement was sensitive for detecting RP progression, and the results of this study indicate that EZ length is appropriate for end points in clinical trials.

Translational Relevance

The study provides a basis for conducting future clinical trials.

Swept-source optical coherence tomography changes and visual acuity among Palestinian retinitis Pigmentosa patients: a cross-sectional study

BACKGROUND

Retinitis pigmentosa (RP) is a heterogeneous group of inherited ocular diseases that result in progressive retinal degeneration. This study aims to describe different Swept-source Optical Coherence Tomographic (SS-OCT) changes in Palestinian RP patients and to explore possible correlations with Visual Acuity (VA).

METHODS

A cross-sectional observational study was conducted on Retinitis Pigmentosa patients diagnosed with RP in a tertiary eye hospital. Full history and ocular examination were made. SS-OCT imaging was done for all eyes assessing the presence of cystoid macular edema, epiretinal membrane, macular holes, and external limiting membrane, ellipsoid zone status. Also, central macular thickness and choroidal vascular thickness were measured.

RESULTS

The study was run on 161 eyes of 81 patients; 53 males and 28 females. The average age at examination was 26.1 (6-78) years. Twenty-six eyes (16.1%) were of syndromic RP patients, mostly Usher syndrome; 20 eyes (12.4%). The mean Logaritmic minimal angle of resolution (LogMAR) of Best Corrected Visual Acuity (BCVA)of the study sample was 0.66 ± 0.7. The most prevalent change was cystoid macular edema [28 eyes, (17.4%)], followed by epiretinal membrane [17eye, (10.6%)]. A macular hole was noted only in one eye (0.6%). Ellipsoid zone and external limiting membrane were absent in 55 eyes (35.0%) and 60 eyes 37.5%. Vitreous hyperreflective foci were found in 35 eyes (43.8%). LogMAR of BCVA was associated significantly with cystoid macular edema (p = 0.001), ellipsoid zone(p = 0.001), and external limiting membrane (p = 0.001).

CONCLUSIONS

Detailed SS-OCT assessment in Palestinian patients diagnosed with RP identified different morphologies from other populations. Cystoid macular edema and vitreous hyperreflective foci may reflect signs of early or intermediate stages of the disease. Disease progression can be monitored by measuring the length/width (area) of ellipsoid zone +/- external limiting membrane and choroidal vascular thickness, which should be evaluated serially using high-resolution OCT.

Linking the Presence of Macular Oedema to Structural and Functional Alterations in Retinitis Pigmentosa

OBJECTIVE

To investigate the association between the central retinal thickness (CRT), the retinal nerve fibre layer thickness (RNFL), and the functional alterations in retinitis pigmentosa (RP) patients.

METHODS

Forty-three patients with typical RP and nineteen age-matched controls, who underwent SD-OCT (macular and optic disc OCT protocols) and electrophysiology, were included. The RP group was divided into two subgroups: with clinical appearance of macular oedema (ME-RP; 30 eyes) and without macular oedema (no-ME; 44 eyes). Central retinal thickness OCT data were averaged in three zones (zone 1 [0°-3°], zone 2 [3°-8°], and zone 3 [8°-15°]) and were evaluated in relation to the RNFL thickness and electrophysiological data.

RESULTS

The ME-RP group showed increased CRT (zone 1) and RNFL thickness compared to the controls and no-ME-RP (p ≤ 0.002). The no-ME-RP group had reduced CRT thickness (all zones; p ≤ 0.018) compared to the controls and ME-RP, whereas the RNFL thickness in the no-ME-RP group was reduced only compared to the ME-RP group (p < 0.001). The ME-RP group showed significantly more attenuated functional responses than the no-ME-RP patients. A significant positive interaction was found between the CRT (zones 1 and 2) and the RNFL thickness within ME-RP (p ≤ 0.010). Significant negative interactions were found between CRT, RNFL thickness, and functional findings within ME-RP (p ≤ 0.049).

CONCLUSION

The presence of macular oedema correlated well with increased RNFL thickness and residual function in RP patients. Such association provides evidence of an underlying transneuronal mechanism of retinal degeneration. Simultaneous monitoring of CRT and RNFL thickness may help in the future to evaluate the progression of the disease and the efficacy of treatments in RP patients.

Impacts of intravitreal anti-VEGF therapy on retinal anatomy and neurophysiology in diabetic macular edema

PURPOSE

To evaluate anatomical and neuroretinal functional aspects in patients with diabetic macular edema (DME) after intravitreal anti-vascular endothelial growth factor (VEGF) therapy, in particular aflibercept.

MATERIALS AND METHODS

This prospective single-centered interventional study was performed at Afyonkarahisar Health Science University Faculty of Medicine, Department of Ophthalmology, where 32 eyes of 32 patients with DME were investigated. All patients received five intravitreal aflibercept injections on a monthly basis and were followed up for ≥ 6 months. After a comprehensive ophthalmological examination, including the measurements of visual acuity and intraocular pressure, and an antero-posterior segment slit-lamp biomicroscopy before and after full pupil dilation, fundus fluorescein angiography and optical coherence tomography were performed at baseline and during the third and sixth months post-therapy. Microperimetry and multifocal electroretinography were also performed at baseline and during the sixth months.

RESULTS

Mean visual acuity increased from 0.73 to 0.57 and 0.33 logarithm of the minimum angle of resolution (logMAR) during the third and sixth months, respectively (p < 0.001). Changes in intraocular pressure were not statistically significant (p = 0.472). There was statistically significantly decreased mean central macular thickness from 390.2 μm to 242.6 and 289.7 μm during the third and sixth months, respectively (p < 0.001). Significantly improved fixation patterns during the sixth month, along with significantly increased macular sensitivity from 8.2 to 14.2 dB (p < 0.001) and significantly decreased local deficit from - 10.3 to 5.5 dB (p < 0.001) were observed. Further, there was a significantly increased N1 amplitude in the first ring and significantly increased P1 amplitude in all rings (p for each parameter < 0.05). There was also significantly decreased N1 wave implicit time in all rings and significantly decreased P1 wave in the second, third, fourth and fifth rings (p for each parameter < 0.05).

CONCLUSIONS

Patients with DME showed profound improvement in the retinal neurophysiological function, which was also accompanied by anatomical and ultrastructural integrity recovery after intravitreal aflibercept therapy. In the pathogenesis of DME, the influence of neurodegeneration has been increasingly gaining significant attention. Consequently, the need to assess neurophysiological effects of anti-VEGF therapy using a variety of diagnostic measures like electrophysiological studies and multimodal imaging technologies is undeniably growing.

Optical coherence tomography in the evaluation of retinitis pigmentosa

BACKGROUND

Optical coherence tomography (OCT) is a non-invasive imaging test that provides easily obtainable and highly reproducible cross-sectional images of the retina. Improved modalities of the OCT that are capable of providing high quality images of not only the retina, but also the deeper structures and vasculature have been developed, including swept-source OCTs and OCT angiography.

MATERIALS AND METHODS

Review.

RESULTS

The use of OCT in the monitoring of retinitis pigmentosa has been well described and numerous signs of disease progression have been studied. Notably among them are the detection of changes to retinal thickness, the ellipsoid zone, the vasculature on OCT angiography, and cystoid macular edema.

CONCLUSION

In this review, we discuss the multiple applications of OCT as a tool in the monitoring of retinitis pigmentosa and its potential use as an outcome measurement in current and future therapeutic endeavors.

Short-term outcomes of subtenon triamcinolone acetonide injections in patients with retinitis pigmentosa-associated cystoid macular edema unresponsive to carbonic anhydrase inhibitors

PURPOSE

To investigate the functional and anatomical results of subtenon triamcinolone acetonide injection (TA) in eyes with retinitis pigmentosa (RP) that had cystoid macular edema (CME) unresponsive to carbonic anhydrase inhibitors (CAIs).

MATERIALS AND METHODS

This is a prospective, interventional study. Forty-eight consecutive eyes that underwent subtenon TA for CME due to RP were recorded. Central macular thickness (CMT), best-corrected visual acuities (BCVAs) and intraocular pressures (IOPs) were evaluated before and after injection at 2nd week, 1st month, 2nd month and 3rd month, respectively. Spectral-domain optical coherence tomography (SD-OCT) was used to show anatomic findings. Complications such as cataract and glaucoma were recorded.

RESULTS

A total of 48 eyes of 42 patients with a mean age of 36.25 ± 15.59 years (range 13 to 63 years) and a mean follow-up of 4.45 ± 0.74 months (range 4 to 6 months) were recorded in the study. The mean initial BCVA increased from 1.09 ± 0.52 to 0.54 ± 0.29 logarithmic minimum angle of resolution (log MAR) (p < 0.001) at 3 months after injection and the mean central macular thickness decreased from 591.45 ± 209.55 µm to 270.83 ± 95.48 µm (p < 0.001). The mean iOP increased from 13.58 ± 2.87 mmHg to 15.91 ± 2.47 mmHg (p < 0.001). Multiple injections (3 injections) in 1 eye, 2 injections in 4 eyes and 1 injection in rest of the eyes were performed at 3-month intervals. Complications such as glaucoma and cataract were not observed in any patient during and after the treatment.

CONCLUSION

In the present study, a significant improvement in visual acuity and CMT were observed in eyes with subtenon TA for CME due to RP unresponsive to CAIS. Further studies with a long follow-up period of the population are required to investigate the role of subtenon TA of CME due to RP.

Outer Retinal Healing After Internal Limiting Membrane Peeling in Diabetic Macular Oedema with Vitreomacular Interface Abnormality Using Three Different Dyes

Purpose: To evaluate the difference in ellipsoid zone and external limiting membrane (EZ/ELM) restoration after vitrectomy with internal limiting membrane (ILM) peeling in diabetic macular oedema with vitreomacular interface abnormalities (VMA DME) patients using 3 different dyes.Methods: Patients with type 2 diabetes mellitus and VMA DME indicated for ILM peelings were included. Disruption of the EZ/ELM was graded and compared among groups (preoperative and 6 months postoperative). Patients were divided into 3 groups according to the dye used: group A: indocyanine green (ICG); group B: trypan blue (TB); and group C: brilliant blue G(BBG).Results: Twenty-six eyes were included in group A, 29 eyes were included in group B, and 28 eyes were included in group C. Improvement in EZ/ELM integrity was observed in 34.6% of group A, 27.6% of group B, and 32.1 % of group C (p = .84). Deterioration of EZ/ELM integrity was observed in 19.2% of group A, 6.9% of group B and 0% of group C (p = .03).Conclusion: ICG resulted in a greater percentage of deteriorated EZ/ELM integrity at 6 months after surgery in cases with pre-treatment ELM interruption. Therefore, ICG should be used with caution in cases with ELM disruption, yet, further studies are recommended.

Phenotypic Characteristics of a French Cohort of Patients with X-Linked Retinoschisis

PURPOSE

To analyze the retinal structure in patients with X-linked retinoschisis (XLRS) using spectral-domain OCT and to correlate the morphologic findings with visual acuity, electroretinographic results, and patient age.

DESIGN

Retrospective, observational study.

PARTICIPANTS

Data from 52 consecutive male patients with molecularly confirmed XLRS were collected retrospectively.

METHODS

Complete clinical evaluation included best-corrected visual acuity, full-field electroretinography, fundus photography, spectral-domain OCT, and fundus autofluorescence. Spectral-domain OCT images were analyzed to determine full thickness of the retina and tomographic structural changes.

MAIN OUTCOME MEASURES

Relationships between age, OCT, and visual acuity were assessed.

RESULTS

One hundred four eyes of 52 patients were included. The mean age at inclusion was 24±15 years (range, 3-57 years). The best-corrected visual acuity ranged from no light perception to 0.1 logarithm of the minimum angle of resolution (mean, 0.6±0.38 logarithm of the minimum angle of resolution). Macular schisis was found in 88% of eyes and macular atrophy was found in 11% of eyes, whereas peripheral schisis was present in 30% of eyes. A spoke-wheel pattern of high and low intensity was the most frequently observed fundus autofluorescence abnormality (51/94 eyes [54%]). The b-to-a amplitude ratio on bright-flash dark-adapted electroretinography was reduced significantly in 45 of 64 eyes (70%). Spectral-domain OCT was available for 97 eyes and showed foveoschisis in 76 of 97 eyes (78%), parafoveal schisis in 10 of 97 eyes (10%), and foveal atrophy in 11 of 97 eyes (11%). Mean central macular thickness (CMT) was of 373.6±140 μm. Cystoid changes were localized mainly in the inner nuclear layer (85/97 eyes [88%]). Qualitative defects in photoreceptor structures were found in most eyes (79/97 eyes [81%]), and the most frequent abnormality was an interruption of the photoreceptor cell outer segment tips (79/79 eyes [100%]). Older age correlated well with lower CMT (correlation coefficient [CC], -0.44; P < 0.001) and with lower photoreceptor outer segment (PROS) length (CC, -0.42; P < 0.001). Lower visual acuity correlated strongly with lower PROS length (CC, -0.53; P < 0.001).

CONCLUSIONS

This study underlined the wide variety of clinical features of XLRS. It highlighted the correlation between visual acuity, patient age, and OCT features, emphasizing the relevance of the latter as potential outcome measure in clinical trials.

Retrospective cohort study exploring whether an association exists between spatial distribution of cystoid spaces in cystoid macular oedema secondary to retinitis pigmentosa and response to treatment with carbonic anhydrase inhibitors

BACKGROUND

Carbonic anhydrase inhibitors (CAIs) are frequently used as an initial step to treat retinitis pigmentosa-associated cystoid macular oedema (RP-CMO). Interestingly, it has been postulated that CAIs might reduce outer nuclear layer (ONL) fluid more effectively than inner nuclear layer (INL) fluid due to better access to retinal pigment epithelium basolateral membrane than neurosensory retina. This retrospective cohort study explores if an association between spatial distribution of cystoid spaces in RP-CMO and CAI response exists.

METHODS

Two independent graders reviewed pretreatment and post-treatment optical coherence tomography (OCT) images of 25 patients (43 eyes) initiated on topical and/or oral CAIs between January 2013 and December 2014. Documentation included the presence/absence of fluid (and layer(s) involved), external limiting membrane, epiretinal membrane (ERM), vitreomacular adhesion/traction, lamellar/full-thickness macular hole and central macular thickness (CMT)/volume.

RESULTS

INL fluid was found in all study eyes. All 13 'responders' (at least 11% reduction of CMT after treatment) demonstrated pretreatment ONL fluid. In seven patients (four responders and three non-responders), complete clearance of ONL fluid was achieved despite persistence of INL fluid. ERM presence was similar in responders and non-responders.

CONCLUSION

In this study, INL fluid was found to be the most common spatial distribution of RP-CMO. However, patients who were classed as a 'responder' to CAI treatment all demonstrated coexisting ONL fluid on their pretreatment OCT scans. This may be explained by CAIs having better access to retinal pigment epithelium basolateral membrane than neurosensory retina. Our study also suggests a minimal impact on response to CAIs by ERM.

Efficacy of additional topical betamethasone in persistent cystoid macular oedema after carbonic anhydrase inhibitor treatments in retinitis pigmentosa

Objective

We investigated the efficacy of additional topical betamethasone in persistent cystoid macular oedema (CMO) after carbonic anhydrase inhibitors (CAIs) therapy.

Methods and analysis

This retrospective cohort study included 16 eyes of 10 patients with retinitis pigmentosa (RP). All patients were previously administered CAI for at least 3 months to treat CMO secondary to RP and lacking an effective reduction (≥11%) of central foveal thickness (CFT). We administered topical 0.1% betamethasone daily in each affected eye following a preceding course of the CAI medication as a first treatment. CMO was diagnosed using spectral-domain optical coherence tomography. CFT was regarded as the average of vertical and horizontal foveal thickness. Best-corrected visual acuity (BCVA) and intraocular pressure (IOP) were obtained from patient medical records. We compared the CFT and BCVA between baseline and the average of 1-3, 5-7, 10-14 and 16-20 months period.

Results

In treatments with brinzolamide in 14 eyes, dorzolamide in 2 eyes and bromfenac in 2 eyes, CFT effectively decreased in 12 of 16 eyes (81%). CFT decreased significantly in 1-3 months (326±102 µm; n=16; P=0.029) and 5-7 months (297±102 µm; n=12; P=0.022) compared with baseline but not within 10-14 months (271±96 µm; n=9; P=0.485) or 16-20 months (281±134 µm; n=9; P=0.289). There were no significant intergroup differences in BCVA throughout the study. Betamethasone treatment was stopped in three patients because of IOP elevation.

Conclusion

Our data suggested that additional betamethasone might improve treatments for persistent CMO. Topical steroids could be an alternative option for managing persistent CMO in RP.

Factors associated with visual acuity in patients with cystoid macular oedema and Retinitis Pigmentosa

PURPOSE

Retinitis pigmentosa is the most common inherited retinal dystrophy. The factors associated with visual acuity in patients with other retinal diseases are well known, but are poorly understood in patients with retinitis pigmentosa. This knowledge is useful for prognosis and to support secondary endpoints in clinical trials.

METHODS

We conducted a cross-sectional study of consecutive patients recruited from the inherited retinal disease service from January 2012 to December 2012. Central macular thickness (CMT) was measured using spectral domain optical coherence tomography.

RESULTS

Data were available for 81 patients and 162 eyes. After multivariable analyses, older age, earlier age of onset of symptoms, and thicker CMT were associated with lower visual acuity. Gender and inheritance pattern were not associated with visual acuity. Each decade older age, younger age of onset, and thicker CMT was associated with 0.12, 0.10, and 0.11 worse logarithm of the minimal angle of resolution units of visual acuity, respectively (p < 0.05 for all).

CONCLUSIONS

Age, age of onset, and CMT are associated with visual acuity and important factors to measure in studies of retinitis pigmentosa.

Retinitis pigmentosa-associated cystoid macular oedema: pathogenesis and avenues of intervention

Hereditary retinal diseases are now the leading cause of blindness certification in the working age population (age 16–64 years) in England and Wales, of which retinitis pigmentosa (RP) is the most common disorder. RP may be complicated by cystoid macular oedema (CMO), causing a reduction of central vision. The underlying pathogenesis of RP-associated CMO (RP-CMO) remains uncertain, however, several mechanisms have been proposed, including: (1) breakdown of the blood-retinal barrier, (2) failure (or dysfunction) of the pumping mechanism in the retinal pigment epithelial, (3) Müller cell oedema and dysfunction, (4) antiretinal antibodies and (5) vitreous traction. There are limited data on efficacy of treatments for RP-CMO. Treatments attempted to date include oral and topical carbonic anhydrase inhibitors, oral, topical, intravitreal and periocular steroids, topical non-steroidal anti-inflammatory medications, photocoagulation, vitrectomy with internal limiting membrane peel, oral lutein and intravitreal antivascular endothelial growth factor injections. This review summarises the evidence supporting these treatment modalities. Successful management of RP-CMO should aim to improve both quality and quantity of vision in the short term and may also slow central vision loss over time.

Radial fundus autofluorescence in the periphery in patients with X-linked retinitis pigmentosa

Purpose

To describe the peripheral autofluorescence images and clinical features of patients with retinal dystrophy who showed radial fundus autofluorescence (FAF) at the posterior pole.

Methods

The authors retrospectively reviewed pooled wide-field FAF images of 711 patients with retinal dystrophy and 56 family members.

Results

Eleven eyes of seven women exhibited radial FAF at the posterior pole. Wide-field FAF showed extension of the radial pattern to the periphery in all eyes except one. One woman showed radial hyper-FAF only in the periphery, not at the posterior pole. These eight individuals were X-linked retinitis pigmentosa patients or carriers. The tapetal-like reflex was not observed in their color fundus photographs. The peripheral visual field showed wedge-shaped restriction in some individuals.

Conclusion

Wide-field FAF imaging can depict radial FAF not only at the posterior pole but also in the periphery in X-linked retinitis pigmentosa carriers. The authors therefore agree with previous reports that radial FAF may be a hallmark of X-linked retinitis pigmentosa.

Macular hole in retinitis pigmentosa patients: microincision vitrectomy with polydimethylsiloxane as possible treatment

PURPOSE

To investigate long-term retinal changes after microincision pars plana vitrectomy surgery (MIVS) for macular hole (MH) in retinitis pigmentosa (RP) patients-retrospective and observational study.

METHODS

Three RP patients suffering from MH were evaluated by means of best corrected visual acuity, anterior and posterior binocular examination, spectralis high-resolution optical coherence tomography, MP-1 microperimetry (MP-1), and full-field electroretinogram (ERG), before MIVS and during the 36-month follow-up. Patients underwent simultaneous MIVS and microincision cataract surgery; IOL was positioned in capsular bag. Patients were hospitalised for 2 days after the surgery. Surgical procedure was performed according the following schedule: surgical removal of crystalline lens, MIVS with 23-gauge sutureless system trocars, core vitreous body removal, peeling of the inner limiting membrane, and balanced sterile saline solution-air-micro-structured polydimethylsiloxane (PDMS) exchange. PDMS tamponade, after 6 months starting from MIVS, was removed.

RESULTS

In all patients visual acuity increased after vitrectomy as a consequence of complete MH closure and restoration of retinal architecture. None of the patients developed ocular hypertension, or re-opening of MH during the 3-year follow-up. MP-1 bivariate contour ellipse area was reduced in its dimensions and improved in all patients demonstrating a better fixation.

CONCLUSIONS

MIVS could be an effective treatment in RP patients with MH if medical therapy is not applicable or not sufficient. Finally more studies will be needed to improve knowledge about this genetic disease.

Photoreceptor inner segment ellipsoid band integrity on spectral domain optical coherence tomography

Spectral domain optical coherence tomography cross-sectional imaging of the macula has conventionally been resolved into four bands. However, some doubts were raised regarding authentication of the existence of these bands. Recently, a number of studies have suggested that the second band appeared to originate from the inner segment ellipsoids of the foveal cone photoreceptors, and therefore the previously called inner segment-outer segment junction is now referred to as inner segment ellipsoidband. Photoreceptor dysfunction may be a significant predictor of visual acuity in a spectrum of surgical and medical retinal diseases. This review aims to provide an overview and summarizes the role of the photoreceptor inner segment ellipsoid band in the management and prognostication of various vitreoretinal diseases.

Comparison of topical dorzolamide and ketorolac treatment for cystoid macular edema in retinitis pigmentosa and Usher's syndrome

PURPOSE

To investigate the topical effect of dorzolamide versus ketorolac on retinitis pigmentosa (RP) and Usher's syndrome (US) macular edema.

METHODS

Prospective, randomized and interventional study. A total of 28 eyes of 18 patients were included. Five eyes had US, 23 had RP. Fifteen eyes were allocated to ketorolac tromethamine 0.5% (4 drops daily regimen) and 13 eyes to dorzolamide hydrochloride 2% (3 drops daily regimen) treatment groups. Snellen's best-corrected visual acuity (BCVA), foveal thickness (FT) and foveal zone thickness (FZT) measured by Stratus® optical coherence tomography (OCT) were evaluated at baseline, 1, 3, 6 and 12 months after treatment.

RESULTS

Patients assigned to ketorolac had a baseline BCVA of 0.37 ± 0.17 logMAR which improved at the end of 1 year to 0.28 ± 0.16 (p = 0.02). Three eyes (20%) of 2 patients improved by 7 letters or more. Mean FT and FZT did not change significantly during the study follow-up. After 1 year of treatment, 4 eyes (27%) of 3 patients showed an improvement of at least 16% of FT and 11% of FZT. Patients assigned to dorzolamide had a baseline BCVA of 0.48 ± 0.34 logMAR which improved in the first 6 months (0.40 ± 0.30; p = 0.01), with a decrease at 1 year (0.42 ± 0.27; p = 0.20). Seven eyes (54%) of 5 patients had an improvement of 7 letters or more. Mean FT and FZT did not change significantly either. After 1 year of treatment, 3 eyes (23%) of 2 patients showed an improvement of at least 16% on FT and 11% on FZT.

CONCLUSIONS

RESULTS suggest that dorzolamide and ketorolac might improve visual acuity and therefore be of interest in selected cases. No relationship between retinal thickness fluctuation and visual acuity was found. Sample size was a limitation to the study.

What is new in central serous chorioretinopathy?

Central serous chorioretinopathy (CSCR) is considered a benign, self-limiting disease. However, as many as third of the patients have recurrent episodes or chronic disease that may cause significant functional impairment. New diagnostic tools and new treatment modalities are emerging in order to improve the functional outcomes of these patients. Spectral domain optical coherence tomography (SD-OCT) has the ability to image individual layers of the retina and choroid. SD-OCT images in CSCR patients have demonstrated increased subfoveal thickness measurements, high reflective deposits in areas of subretinal precipitates and changes in the Retinal pigment epithelium layers of the asymptomatic eyes of patients with supposedly unilateral CSCR. A positive correlation was found between the level of distribution to the layer of inner segment/outer segment junction of the photoreceptors and the visual impairment. Fundus autoflouresence images show a wide variety during different stages of the disease in CSCR patients. Minimal abnormalities during the early stages are followed by hyperautofluoresence in the detached area in later stages, often in a manner of inferior gravitation and at the borders of the detachments. The chronic phase is characterized by varying degrees of atrophy and areas of decreased autofluorescence surrounding areas of chronic leaks. These changes help differentiate an active disease from an inactive state. Multifocal electroretinography (mfERG) has the ability to demonstrate a persistent depression despite the resolution of subretinal detachments. It is therefore being investigated as a follow up tool for patients with chronic CSCR. An excellent correlation was found between changes in mfERG and visual function. Macular microperimetry, measuring retinal sensitivity within the central visual field, is intended to compensate for the underestimation of visual impairment in patients with macular diseases. Reduced retinal sensitivity was found in areas of previous subretinal fluids in CSCR patients. The device can also serve as a follow up tool in these patients. Regarding treatment in CSCR patients, focal argon laser photocoagulation treatment may be applied to small extrafoveal leaks. However, the main purpose of this treatment is to shorten disease duration, with no advantage over observation regarding final visual outcome, rate of progression to chronic CSCR or number of recurrences. Photodynamic therapy (PDT) with verteporfin has been shown to completely resolve serous detachment in 60%-80% of patients and to have a partial affect in the remaining patients. Reduced-fluence treatment is replacing full-fluence therapy in order to minimize side effects with no accompanying reduced effectiveness. Visual acuity is also improved following reduced-fluence PDT compared to placebo. It has also been found that patients with intense hyperfluorescence are more likely to show resolution of accumulating fluid compared to patients with mild or no leakage observed on indocyanine-green angiography prior to treatment. Regarding newer treatment modalities, intravitreal injections of anti-vascular endothelial growth factor agents have a limited effect in patients with CSCR. Recent reports have not demonstrated an advantage for this treatment in regards to anatomic and functional outcome. Micropulse diode laser was not proven to be safer or more effective than argon laser or PDT. Corticosteroid antagonists, not tested in controlled trials, may have a beneficial effect in patients with CSCR. Aspirin may also play a role in treating these patients, with rapid recovery of visual acuity and reduced number of recurrences observed. In conclusion, imaging is evolving rapidly while the clinical implications of these new imaging modalities are less clear. Large randomized trials investigating different treatment modalities are still lacking.

Cellular responses following retinal injuries and therapeutic approaches for neurodegenerative diseases

Retinal neurodegenerative diseases like age-related macular degeneration, glaucoma, diabetic retinopathy and retinitis pigmentosa each have a different etiology and pathogenesis. However, at the cellular and molecular level, the response to retinal injury is similar in all of them, and results in morphological and functional impairment of retinal cells. This retinal degeneration may be triggered by gene defects, increased intraocular pressure, high levels of blood glucose, other types of stress or aging, but they all frequently induce a set of cell signals that lead to well-established and similar morphological and functional changes, including controlled cell death and retinal remodeling. Interestingly, an inflammatory response, oxidative stress and activation of apoptotic pathways are common features in all these diseases. Furthermore, it is important to note the relevant role of glial cells, including astrocytes, Müller cells and microglia, because their response to injury is decisive for maintaining the health of the retina or its degeneration. Several therapeutic approaches have been developed to preserve retinal function or restore eyesight in pathological conditions. In this context, neuroprotective compounds, gene therapy, cell transplantation or artificial devices should be applied at the appropriate stage of retinal degeneration to obtain successful results. This review provides an overview of the common and distinctive features of retinal neurodegenerative diseases, including the molecular, anatomical and functional changes caused by the cellular response to damage, in order to establish appropriate treatments for these pathologies.

Contrast visual acuity in patients with retinitis pigmentosa assessed by a contrast sensitivity tester

Purpose:

To assess contrast visual acuity (CVA) in patients with retinitis pigmentosa (RP) and compare the result with standard visual acuity (VA), retinal thickness, status of inner segment/outer segment junction, and central visual field.

Materials and Methods:

Thirty-nine eyes of 39 patients with RP and 39 eyes of 39 healthy individuals were studied. To see the difference in CVA between RP patients and normal controls, only subjects with standard VA of 1.0 (20/20) or better were included. This was a cross-sectional study. CVA in various light conditions was measured with CAT-2000 and was compared between patients and controls. CVA of patients was further analyzed for association with other parameters including foveal retinal thickness, outer nuclear layer thickness, the status of inner segment/outer segment junction measured with optical coherence tomography (OCT), and visual field mean deviation (MD) measured with Humphrey field analyzer 10-2 program.

Results:

CVA impairment was evident in RP patients compared to controls (P < 0.01, in all measurement conditions). Multivariate analysis showed association of logarithm of the minimum angle of resolution (logMAR) with CVAs in several conditions. None of the OCT measurements was associated with CVA. When patients were divided into three groups based on MD, the most advanced group (MD worse than or equal to –20 dB) showed impairment of mesopic CVA (P < 0.05, under mesopic condition of 100% without glare, with glare, and 25% without glare).

Conclusion:

CVA impairment was confirmed in RP patients, especially in advanced cases. CVA measured with CAT-2000 may be a useful tool for assessing foveal function in RP patients.

Influence of cataract surgery on optical coherence tomography and neurophysiology measurements in patients with retinitis pigmentosa

PURPOSE

To evaluate the effect of uncomplicated cataract phacoemulsification on the measurements of visual evoked potentials (VEP), pattern electroretinogram (PERG), and macular and retinal nerve fiber layer (RNFL) using 2 spectral-domain optical coherence tomography (OCT) instruments, the Cirrus OCT (Carl Zeiss Meditech) and Spectralis OCT (Heidelberg Engineering), in patients with retinitis pigmentosa (RP), and to assess the reliability of the OCT measurements before and after cataract surgery.

DESIGN

Observational cross-sectional study.

METHODS

Thirty-five eyes of 35 patients with RP (20 men and 15 women, 45-66 years) who underwent cataract phacoemulsification were studied. At 1 month before and 1 month after surgery, visual acuity, VEP, PERG, and 3 repetitions of scans using the RNFL and macular analysis protocols of the Cirrus and Spectralis OCT instruments were performed. The differences in measurements between the 2 visits were analyzed. Repeatability of OCT measurements was evaluated by calculating the coefficients of variation.

RESULTS

VEP amplitude, RNFL thicknesses provided by Cirrus and Spectralis, and macular measurements provided by Cirrus OCT differed between the 2 visits. VEP latency, PERG measurements, and macular thicknesses provided by the Spectralis OCT before surgery did not differ significantly from those after surgery. The OCT repeatability was better after surgery, with lower coefficients of variation for scans performed after surgical removal of the cataract. The nuclear, cortical, and posterior subcapsular types of cataracts did not show different repeatability.

CONCLUSIONS

The presence of cataracts affects VEP amplitude, RNFL, and macular measurements performed with OCT in eyes with RP. Image repeatability significantly improves after cataract phacoemulsification.

Central serous chorioretinopathy: update on pathophysiology and treatment

Recent technological advances--new pathophysiological insights, new imaging techniques for diagnosis and management, and new treatments--have led to an improved understanding of central serous chorioretinopathy (CSC). The primary role of the choroid has become more widely accepted with widespread use of indocyanine green angiography. Optical coherence tomography (OCT), and particularly enhanced depth imaging OCT, demonstrate a thickened and engorged choroid. Adaptive optics, fundus autofluorescence, multifocal electroretinography, microperimetry, and contrast sensitivity testing reveal that patients with even a mild course suffer previously undetected anatomic and functional loss. Although focal laser and photodynamic therapy are the current standard of care for persistent subretinal fluid in CSC, they are not appropriate in all cases, and the optimal timing of intervention remains unclear.

Macular cone abnormalities in retinitis pigmentosa with preserved central vision using adaptive optics scanning laser ophthalmoscopy

PURPOSE

To assess macular photoreceptor abnormalities in eyes with retinitis pigmentosa (RP) with preserved central vision using adaptive optics scanning laser ophthalmoscopy (AO-SLO).

METHODS

Fourteen eyes of 14 patients with RP (best-corrected visual acuity 20/20 or better) and 12 eyes of 12 volunteers underwent a full ophthalmologic examination, fundus autofluorescence, spectral-domain optical coherence tomography (SD-OCT), and imaging with a prototype AO-SLO system. Cone density and spatial organization of the cone mosaic were assessed using AO-SLO images.

RESULTS

In 3 eyes with RP and preserved central vision, cones formed a mostly regular mosaic pattern with small patchy dark areas, and in 10 eyes, the cone mosaic patterns were less regular, and large dark regions with missing cones were apparent. Only one eye with RP demonstrated a normal, regular cone mosaic pattern. In eyes with RP, cone density was significantly lower at 0.5 mm and 1.0 mm from the center of the fovea compared to normal eyes (P<0.001 and 0.021, respectively). At 0.5 mm and 1.0 mm from the center of the fovea, a decreased number of cones had 6 neighbors in eyes with RP (P = 0.002 for both). Greater decrease in cone density was related to disruption of the photoreceptor inner segment (IS) ellipsoid band on SD-OCT images (P = 0.044); however, dark regions were seen on AO-SLO even in areas of continuous IS ellipsoid on SD-OCT. Decreased cone density correlated thinner outer nuclear layer (P = 0.029) and thinner inner segment and outer segment thickness (P = 0.011) on SD-OCT.

CONCLUSIONS

Cone density is decreased and the regularity of the cone mosaic spatial arrangement is disrupted in eyes with RP, even when visual acuity and foveal sensitivity are good. AO-SLO imaging is a sensitive quantitative tool for detecting photoreceptor abnormalities in eyes with RP.

Optical coherence tomography in retinitis pigmentosa: reproducibility and capacity to detect macular and retinal nerve fiber layer thickness alterations

PURPOSE

To evaluate the ability of time-domain and Fourier-domain optical coherence tomographies (OCTs) to detect macular and retinal nerve fiber layer atrophies in retinitis pigmentosa (RP). To test the intrasession reproducibility using three OCT instruments (Stratus, Cirrus, and Spectralis).

METHODS

Eighty eyes of 80 subjects (40 RP patients and 40 healthy subjects) underwent a visual field examination, together with 3 macular scans and 3 optic disk evaluations by the same experienced examiner using 3 OCT instruments. Differences between healthy and RP eyes were compared. The relationship between measurements with each OCT instrument was evaluated. Repeatability was studied by intraclass correlation coefficients and coefficients of variation.

RESULTS

Macular and retinal nerve fiber layer atrophies were detected in RP patients for all OCT parameters. Macular and retinal nerve fiber layer thicknesses, as determined by the different OCTs, were correlated but significantly different (P < 0.05). Reproducibility was moderately high using Stratus, good using Cirrus and Spectralis, and excellent using the Tru-track technology of Spectralis. In RP eyes, measurements showed higher variability compared with healthy eyes.

CONCLUSION

Differences in thickness measurements existed between OCT instruments, despite there being a high degree of correlation. Fourier-domain OCT can be considered a valid and repeatability technique to detect retinal nerve fiber layer atrophy in RP patients.

Predictive Factors in OCT Analysis for Visual Outcome in Exudative AMD

Background. Reliable predictive factors for therapy outcome may enable treating physicians to counsel their patients more efficiently concerning probability of improvement or time point of discontinuation of a certain therapy. Methods. This is a retrospective analysis of 87 patients with exudative age-related macular degeneration who received three monthly intravitreal ranibizumab injections. Visual acuity before initiation of intravitreal therapy and 4–6 weeks after last intravitreal injection was compared and related to the preoperative visualisation of continuity of the outer retinal layers as assessed by OCT: external limiting membrane (ELM), inner photoreceptor segments (IPS), junction between inner and outer segments (IS/OS), and outer photoreceptor segments (OPS). Results. Visual acuity increased in 40 of 87 (46.0%) patients, it remained stable in 25 (28.7%), and 22 (25.3%) patients had decreased visual acuity four to six weeks after triple intravitreal ranibizumab injections. No statistically significant predictive value could be demonstrated for grade of continuity of outer retinal layers concerning visual acuity development. Conclusions. In our series of AMD patients, grade of continuity of outer retinal layers was not a significant predictive value for visual acuity development after triple ranibizumab injections.

Qualitative and quantitative OCT response of diffuse diabetic macular oedema to macular laser photocoagulation

PURPOSE

To assess the quantitative and morphological changes of the macula in response to macular grid laser for diabetic macular oedema (DMO) using optical coherence tomography (OCT).

PATIENTS AND METHODS

Cirrus OCT macular cube scans of 30 eyes of 25 patients were retrospectively analysed before and 4 months after macular grid laser for diffuse DMO. The oedema was quantified and response evaluated in the nine early-treatment diabetic retinopathy study (ETDRS) zones of the macula. Post-laser OCT changes were compared with the baseline features, including morphology patterns, changes in both logarithmic transformed (logOCT) and standardised average macular thickness (AMT), total macular volume, number of parafoveal quadrants involved, and the presence of intact 3rd hyper-reflective band (HRB).

RESULTS

The rate of change of retinal thickness in response to laser was maximum in the central (8.17%) and perifoveal inferior quadrants (0.04%). Diffuse retinal thickening on OCT responded best to treatment. The AMT of 300-350 μm had the worst response (+0.94%). Eyes with less than four quadrants of oedema showed good response. Disrupted HRB was associated with poor visual gain (-0.33 ETDRS letters).

CONCLUSION

The topographic location of oedema on the retinal map and the morphological patterns of the oedema on OCT are useful predictors of treatment response in diffuse DMO.

Method for deriving visual field boundaries from OCT scans of patients with retinitis pigmentosa

The location of the loss of the inner segment (IS)/outer segment (OS) border, as seen with frequency domain optical coherence tomography (fdOCT), was determined on fdOCT scans from patients with retinitis pigmentosa. A comparison to visual field loss supported the hypothesis, based upon previous work, that the point at which the IS/OS border disappears provides a structural marker for the edge of the visual field. Repeat fdOCT measures showed good within day reproducibility, while data obtained on average 22.5 months later showed signs of progression. The IS/OS contour shows promise as a measure for following changes in patients undergoing treatment.

The significance of external limiting membrane status for visual acuity in age-related macular degeneration

PURPOSE

To evaluate status of the external limiting membrane (ELM) as a contributor of visual acuity (VA) in age-related macular degeneration (AMD).

DESIGN

Hospital-based, cross-sectional study.

METHODS

We retrospectively reviewed spectral-domain optical coherence tomography images of 158 patients with AMD who had undergone photodynamic therapy and classified them based on the status of the ELM: absent, discontinuous, or complete. We simultaneously assessed foveal thickness, presence or absence of subretinal fluid/mass, presence or absence of subretinal pigment epithelium fluid/mass, status of the inner segment/outer segment (IS/OS) junction, and status of the intermediate line between the IS/OS junction and retinal pigment epithelium. Correlation coefficients between each parameter and VA were analyzed.

RESULTS

There was a strong correlation between ELM status and VA (r = -0.75, P < .001), and that was higher than that of the IS/OS (r = -0.69, P < .001). Multivariate analysis showed that ELM status is the most important factor for VA. Other parameters that correlated with VA included age, status of the intermediate line, and presence of subretinal or subretinal pigment epithelium fibrosis. Foveal thickness showed V-shaped correlation, with the dividing line around 200 mum.

CONCLUSION

ELM status may be more useful than is IS/OS status in evaluation of retinal morphology and function in patients with AMD.

Relationship between optical coherence tomography retinal parameters and visual acuity in diabetic macular edema

PURPOSE

To investigate the relationship between optical coherence tomography (OCT)-derived measurements of retinal morphology and visual acuity in patients with diabetic macular edema.

DESIGN

Retrospective cross-sectional study.

PARTICIPANTS

A total of 67 consecutive patients (67 eyes) with diabetic macular edema (DME) who underwent Stratus OCT imaging (Carl Zeiss Meditec, Inc., Dublin, CA).

METHODS

Best-corrected Snellen visual acuity was recorded for each patient. Raw exported Stratus OCT images for each patient were analyzed using custom software entitled "OCTOR," which allows the precise positioning of prespecified boundaries on individual B-scans. Thickness, volume, and intensity were calculated for neurosensory retina and subretinal fluid. In addition, photoreceptor outer segment (POS) thickness was quantified.

MAIN OUTCOME MEASURES

Optical coherence tomography-derived measurements of retinal morphology and visual acuity.

RESULTS

The Spearman coefficient values (r) of the correlation between OCTOR-derived measurements of central subfield thickness, intensity, subretinal fluid volume, and POS thickness and the logarithm of the minimum angle of resolution visual acuities were 0.3428 (P = 0.005), -0.2658 (P = 0.03), -0.2683 (P = 0.38), and -0.3703 (P = 0.002), respectively. Multivariate models with stepwise selection revealed a cumulative R(2) of 0.4305 in the total study population, with R(2) of 0.4999 and 0.7628 in the untreated and prior focal laser groups, respectively.

CONCLUSIONS

Subanalysis and quantification of OCT features in eyes with DME seem to be of value. In particular, POS thickness seems to be an important predictor of function and visual acuity in patients with DME.

A comparison of visual field sensitivity to photoreceptor thickness in retinitis pigmentosa

PURPOSE

To explore the relationship between visual field sensitivity and photoreceptor layer thickness in patients with retinitis pigmentosa (RP).

METHODS

Static automated perimetry (central 30-2 threshold program with spot size III; Humphrey Field Analyzer; Carl Zeiss Meditec, Inc., Dublin, CA) and frequency domain optical coherence tomography (Fd-OCT) scans (Spectralis HRA+OCT; Heidelberg Engineering, Vista, CA) were obtained from 10 age-matched normal control subjects and 20 patients with RP who had retained good central vision (better than 20/32). The outer segment (OS+) thickness (the distance between retinal pigment epithelium [RPE])/Bruch's membrane [BM] to the photoreceptor inner-outer segment junction), outer nuclear layer (ONL), and total retinal thickness were measured at locations corresponding to visual field test loci up to 21 degrees eccentricity.

RESULTS

The average OS+ thickness in the control eyes was 63.1 +/- 5.2 microm, varying from approximately 69 microm in the foveal center to 56 microm at 21 degrees eccentricity. In patients with RP, OS+ thickness was below normal limits outside the fovea, and thickness decreased with loss in local field sensitivity, reaching an asymptotic value of 21.5 microm at approximately -10 dB. The ONL thickness also decreased with local field sensitivity loss. Although relative OS thickness was linearly related to visual field loss at all locations examined, a slightly better correlation was found between the product of OS and ONL thickness and visual field loss.

CONCLUSIONS

In patients with RP with good foveal sensitivity, the OS thickness and the product of OS thickness and ONL thickness (assumed to represent the number of photoreceptors) decreases linearly with loss of local field sensitivity. In general, in regions where perimetric sensitivity loss is -10 dB or worse, the OS+ thickness approaches the thickness of the RPE/BM complex.

Relationship between photoreceptor outer segment length and visual acuity in diabetic macular edema. Retina. 2010;30:63-70. [PMID: 19952996 DOI: 10.1097/iae.0b013e3181bd2c5a]

PURPOSE

The purpose of this study was to quantify photoreceptor outer segment (PROS) length in 27 consecutive patients (30 eyes) with diabetic macular edema using spectral domain optical coherence tomography and to describe the correlation between PROS length and visual acuity.

METHODS

Three spectral domain-optical coherence tomography scans were performed on all eyes during each session using Cirrus HD-OCT. A prototype algorithm was developed for quantitative assessment of PROS length. Retinal thicknesses and PROS lengths were calculated for 3 parameters: macular grid (6 x 6 mm), central subfield (1 mm), and center foveal point (0.33 mm). Intrasession repeatability was assessed using coefficient of variation and intraclass correlation coefficient. The association between retinal thickness and PROS length with visual acuity was assessed using linear regression and Pearson correlation analyses. The main outcome measures include intrasession repeatability of macular parameters and correlation of these parameters with visual acuity.

RESULTS

Mean retinal thickness and PROS length were 298 mum to 381 microm and 30 microm to 32 mum, respectively, for macular parameters assessed in this study. Coefficient of variation values were 0.75% to 4.13% for retinal thickness and 1.97% to 14.01% for PROS length. Intraclass correlation coefficient values were 0.96 to 0.99 and 0.73 to 0.98 for retinal thickness and PROS length, respectively. Slopes from linear regression analyses assessing the association of retinal thickness and visual acuity were not significantly different from 0 (P > 0.20), whereas the slopes of PROS length and visual acuity were significantly different from 0 (P < 0.0005). Correlation coefficients for macular thickness and visual acuity ranged from 0.13 to 0.22, whereas coefficients for PROS length and visual acuity ranged from -0.61 to -0.81.

CONCLUSION

Photoreceptor outer segment length can be quantitatively assessed using Cirrus HD-OCT. Although the intrasession repeatability of PROS measurements was less than that of macular thickness measurements, the stronger correlation of PROS length with visual acuity suggests that the PROS measures may be more directly related to visual function. Photoreceptor outer segment length may be a useful physiologic outcome measure, both clinically and as a direct assessment of treatment effects.