Association between optic atrophy 1 polymorphisms and primary open angle glaucoma risk: Based on a meta-analysis

BACKGROUND

Emerging evidence suggested a significant association between optic atrophy 1 (OPA1) polymorphisms and primary open angle glaucoma (POAG) risk. However, the current data are inconsistent or even contradictory. Given these, we conducted a meta-analysis to examine the precise association between OPA1 polymorphisms and POAG risk.

MATERIALS AND METHODS

Online databases were retrieved, and the related studies were reviewed from inception to December 1, 2022. Odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were calculated to examine the statistical power of each genetic model. In addition, heterogeneity, sensitivity, cumulative analysis, and publication bias were analyzed to guarantee statistical power.

RESULT

Overall, 14 studies within 11 publications (involving 2,413 POAG patients and 1,904 controls) were included and some significant association between OPA1 rs166850 C/T (T vs. C: OR = 1.24, 95%CI = 1.06-1.45, P = 0.01, I2 = 39.0%; CT vs. CC: OR = 1.37, 95%CI = 1.05-1.79, P = 0.02, I2 = 41.6%; CT + TT vs. CC: 1.37, 95%CI = 1.06-1.77, P = 0.02, I2 = 41.6%), rs10451941T/C (TC + CC vs. TT: OR = 1.79, 95%CI = 1.41-2.28, P < 0.01, I2 = 71.9%) polymorphisms and POAG susceptibility. In addition, further significant associations were also observed in the stratified analysis, especially in normal tension glaucoma groups and Caucasian descendants.

CONCLUSION

The observed evidences suggest that OPA1 polymorphisms may be associate with POAG susceptibility significantly.

The Role of Optical Coherence Tomography Angiography in Glaucoma

Glaucoma is the leading cause of irreversible vision loss and comprises a group of chronic optic neuropathies characterized by progressive retinal ganglion cell (RGC) loss. Various etiologies, including impaired blood supply to the optic nerve, have been implicated for glaucoma pathogenesis. Optical coherence tomography angiography (OCTA) is a non-invasive imaging modality for visualizing the ophthalmic microvasculature. Using blood flow as an intrinsic contrast agent, it distinguishes blood vessels from the surrounding tissue. Vessel density (VD) is mainly used as a metric for quantifying the ophthalmic microvasculature. The key anatomic regions for OCTA in glaucoma are the optic nerve head area including the peripapillary region, and the macular region. Specifically, VD of the superficial peripapillary and superficial macular microvasculature is reduced in glaucoma patients compared to unaffected subjects, and VD correlates with functional deficits measured by visual field (VF). This renders OCTA similar in diagnostic capabilities compared to structural retinal nerve fiber layer (RNFL) thickness measurements, especially in early glaucoma. Furthermore, in cases where RNFL thickness measurements are limited due to artifact or floor effect, OCTA technology can be used to evaluate and monitor glaucoma, such as in eyes with high myopia and eyes with advanced glaucoma. However, the clinical utility of OCTA in glaucoma management is limited due to the prevalence of imaging artifacts. Overall, OCTA can play a complementary role in structural OCT imaging and VF testing to aid in the diagnosis and monitoring of glaucoma.

Validation of Diagnostic Codes to Identify Glaucoma in Taiwan's Claims Data: A Multi-Institutional Study

Background

Healthcare databases play a crucial role in improving our understanding of glaucoma epidemiology, which is the leading cause of irreversible blindness globally. However, the accuracy of diagnostic codes used in these databases to detect glaucoma is still uncertain.

Aim

To assess the accuracy of ICD-9-CM and ICD-10-CM codes in identifying patients with glaucoma, including two distinct subtypes, primary open-angle glaucoma (POAG) and primary angle-closure glaucoma (PACG).

Methods

We analyzed electronic medical records data from a 2% random sample of patients who newly underwent visual field examination in Taiwan's largest multi-institutional healthcare system from 2011 to 2020. The diagnosis of glaucoma was confirmed by two ophthalmologists, based on the glaucoma diagnostic criteria. The positive predictive value (PPV), negative predictive value (NPV), sensitivity and specificity for ICD-9-CM codes 365.1X and 365.2X, and ICD-10-CM codes H4010X, H4011X, H4012X, H4020X, H4021X, H4022X, H4023X and H4024X for glaucoma were calculated.

Results

We randomly selected 821 patients (mean age: 56.9 years old; female: 50.5%) from the original cohort of 41,050 newly receiving visual field examination in the study. Among 464 cases with an ICD-9-CM glaucoma code, the sensitivity, specificity, PPV and NPV for glaucoma were 86.5, 96.5, 91.9, and 90.9%, respectively. Among 357 cases with an ICD-10-CM glaucoma code, the sensitivity, specificity, PPV and NPV for glaucoma were 87.0, 92.8, 92.2 and 87.9%, respectively. The accuracy of diagnostic codes to identify POAG and PACG remained consistent.

Conclusion

The diagnostic codes were highly reliable for identifying cases of glaucoma in Taiwan's routine healthcare practice. These results provide confidence when using ICD-9-CM and ICD-10-CM codes to define glaucoma cases in healthcare database research in Taiwan.

Successful Management of Bilateral Uncontrolled Advanced Primary Open Angle Glaucoma in a Pregnant Woman during the Restrictive COVID-19 Lockdown

COVID-19 is a viral illness that can cause severe respiratory symptoms. COVID-19 has caused a worldwide pandemic that necessitated many countries to perform a national lockdown. In Jordan, a lockdown was imposed by the government. During the lockdown, the hospitals were only dealing with outpatient emergency cases, urgent referrals from primary or secondary health institutions, and inpatients whose medical conditions required keeping them admitted. Elective clinics and surgeries were canceled. At the King Abdullah University Hospital (KAUH), which is the only tertiary center in northern Jordan, we dealt with an unusual case of uncontrolled and advanced primary open angle glaucoma in a 38-year-old pregnant female patient. The patient was presented with an intraocular pressure (IOP) of 53 mmHg in the right eye and 40 mmHg in the left eye despite using dorzolamide and timolol eye drops twice daily. The angle was opened in gonioscopy. The decision was made to implant Ahmed glaucoma valves (AGV) in each eye in one session under general anesthesia which was performed successfully. At the last follow-up visit 4 years later, the IOP was maintained at 15 mmHg.

Efficacy and safety of Usights UC100 illuminated microcatheter in microcatheter-assisted trabeculotomy

AIM

To evaluate the efficacy and safety of Usights UC100 illuminated microcatheter in microcatheter-assisted trabeculotomy (MAT).

METHODS

Totally 10 eyes of 10 patients with primary open angle glaucoma (POAG) who underwent MAT facilitated by Usights UC100 (5 eyes) or iTrack (5 eyes) were reviewed. The success of this surgery was defined as intraocular pressure (IOP) <22 mm Hg with >30% reduction, without oral glaucoma medications, or additional glaucoma surgery.

RESULTS

The mean pre-operative IOP was 25.38±10.22 mm Hg in the Usights UC100 group and 19.98±3.87 mm Hg in the iTrack group. MAT was achieved in all eyes in both groups. The success rates for the Usights UC100 group and iTrack groups were in all and 4 eyes, respectively. Both microcatheters produced a statistically significant reduction in IOP, and eyes using Usights UC100 achieved a lower IOP than the iTrack group at 3mo follow-up (12.58±1.52 and 14.84±1.89 mm Hg, respectively), but no statistical significance was there. No severe side effects were observed in either group.

CONCLUSION

MAT using Usights UC100 or iTrack both achieve significant pressure reduction in cases of POAG, and Usights UC100 is as safe as iTrack.

A highly sensitive fluorescent probe RN-NA reveals peroxynitrite as a novel biomarker for primary open angle glaucoma

AIM

To directly quantify peroxynitrite (ONOO-) using a highly sensitive fluorescence resonance energy transfer probe RN-NA, investigate the association between ONOO- and primary open angle glaucoma (POAG), and clarify whether RN-NA could be used as a potential tool for POAG diagnosis.

METHODS

Plasma and aqueous humor (AH) samples were collected from POAG patients (n=100, age: 59.70±6.87y) and age-related cataract (ARC) patients (n=100, age: 61.15±4.60y) admitted to our hospital. Next, RN-NA was used to detect ONOO- in plasma and AH samples, and the relationship between ONOO- level and POAG was analyzed using binary logistic regression. Besides, Pearson correlation analysis was applied to characterize the correlation of the levels of ONOO- with the patients' age, intraocular pressure (IOP), and mean deviation of visual field testing. The ONOO- scavenger MnTMPyP was employed to treat the 3-morpholinosyndnomine (SIN-1)-induced ocular hypertension in mice (n=7, 6-8wk). Finally, the IOP and ONOO- in both eyes were measured 30min after the last drug treatment.

RESULTS

ONOO- levels of AH and plasma were significantly higher in the POAG group than in the ARC group (P<0.01). Additionally, ONOO- levels were closely correlated with POAG in a binary logistic regression analysis [odds ratio (OR)=1.008, 95% confidence interval (CI): 1.002-1.013, P<0.01 for AH; OR=1.004, 95%CI: 1.002-1.006, P<0.001 for plasma]. Pearson correlation analysis showed that ONOO- levels in AH or plasma were positively associated with visual field defects (R=0.51, P<0.01 for AH; R=0.45, P<0.001 for plasma), and ONOO- levels in plasma and AH were correlated in the POAG group (R=0.69, P<0.001). However, administering MnTMPyP to mouse eyes reversed the elevated IOP caused by SIN-1 (P<0.05).

CONCLUSION

ONOO- levels in AH and plasma, detected by RN-NA, are significantly related to POAG and positively correlated with visual field defects in POAG patients. Hence, ONOO- is a potential biomarker of POAG, especially advanced POAG. Besides, anti-nitration compounds may be novel ocular hypotensive agents based on the animal study.

Prevalence and Characteristics of Glaucoma Among Patients Presenting to Ophthalmology Clinics in a Tertiary Hospital in the Kingdom of Bahrain

Introduction The aim of this study was to determine the prevalence and characteristics of glaucoma in patients presenting to the ophthalmology department in a tertiary hospital in Bahrain for the first time. Methods A retrospective study was conducted at the Salmaniya Medical Complex, Manama, Bahrain. The medical records of all patients who presented for the first time to an eye clinic between January and December 2019 were reviewed. Patients who were diagnosed with glaucoma were included in this study. Data regarding age, sex, ethnicity, type of glaucoma, previous treatment, best corrected visual acuity, cup-to-disc ratio, intraocular pressure, central corneal thickness, optical coherence tomography (OCT) retinal nerve fiber layer (RNFL), and visual field findings were collected. Results Of a total of 18,238 new patients in 2019, 173 patients (0.97%) had glaucoma. The mean age of patients with glaucoma was 59.6 ± 11.3 years and approximately 60% of them were males (n=103, 59.5%). In 93% of the cases, glaucoma involved both eyes (n=161). Primary open-angle glaucoma (n=97, 56.1%), normal tension glaucoma (n=28, 16.2%), and chronic angle closure glaucoma (n=15, 8.7%) were the most frequently encountered types of glaucoma. Approximately 16.76% (n=29) of the patients were blind in one or two eyes at the time of presentation. Conclusion There seems to be a low prevalence of glaucoma among the encountered cases on the first visit to ophthalmology clinics in Bahrain, with primary open-angle glaucoma being the most common type.

Ocular Pathology and Genetics: Transformative Role of Artificial Intelligence (AI) in Anterior Segment Diseases

Artificial intelligence (AI) has become a revolutionary influence in the field of ophthalmology, providing unparalleled capabilities in data analysis and pattern recognition. This narrative review delves into the crucial role that AI plays, particularly in the context of anterior segment diseases with a genetic basis. Corneal dystrophies (CDs) exhibit significant genetic diversity, manifested by irregular substance deposition in the cornea. AI-driven diagnostic tools exhibit promising accuracy in the identification and classification of corneal diseases. Importantly, chat generative pre-trained transformer (ChatGPT)-4.0 shows significant advancement over its predecessor, ChatGPT-3.5. In the realm of glaucoma, AI significantly contributes to precise diagnostics through inventive algorithms and machine learning models, surpassing conventional methods. The incorporation of AI in predicting glaucoma progression and its role in augmenting diagnostic efficiency is readily apparent. Additionally, AI-powered models prove beneficial for early identification and risk assessment in cases of congenital cataracts, characterized by diverse inheritance patterns. Machine learning models achieving exceptional discrimination in identifying congenital cataracts underscore AI's remarkable potential. The review concludes by emphasizing the promising implications of AI in managing anterior segment diseases, spanning from early detection to the tailoring of personalized treatment strategies. These advancements signal a paradigm shift in ophthalmic care, offering optimism for enhanced patient outcomes and more streamlined healthcare delivery.

Acceptance of Selective Laser Trabeculoplasty as a First-Line Treatment for Primary Open-Angle Glaucoma in Saudi Arabia

PURPOSE

Glaucoma is the second leading cause of blindness worldwide. Early detection and timely treatment are crucial to reducing disease progression. Selective laser trabeculoplasty (SLT) has proven efficacious as a primary treatment for primary open-angle glaucoma. This study aims to evaluate the acceptance among Saudi ophthalmologists of using SLT as a primary treatment for glaucoma.

METHODS

This cross-sectional study enrolled 128 ophthalmologists practicing in Saudi Arabia. Data collection was conducted using a structured online questionnaire, which evaluated sociodemographic data, current glaucoma practice, the technology acceptance model (TAM), and potential barriers to incorporating SLT as the primary treatment for glaucoma.

RESULTS

The mean age of the participants was 40 ± 9.6 years, with 65.6% being male. Almost one-third were glaucoma specialists, and 89% followed the American Academy of Ophthalmology recommendations for managing glaucoma patients. The majority (96.1%) used medical treatment as the initial therapy, 72.7% agreed that SLT is safe, and 59.4% agreed that it rapidly controls intraocular pressure. Nearly half of the participants were willing to use SLT as the primary treatment, yet only 42.2% considered themselves experienced enough to do so. The most reported barriers were inadequate training (47.7%), non-availability of SLT equipment (41.4%), and low efficacy as reported by 27.3% of participants.

CONCLUSION

Despite the good overall acceptance of SLT as a first-line treatment for glaucoma, most participants still preferred medical therapy as the primary treatment. To overcome the barriers to incorporating SLT, Saudi ophthalmologists require more training and access to equipment to effectively implement this modality in their practices.

The Evolution and Current Landscape of Minimally Invasive Glaucoma Surgeries: A Review

This review examines the evolution, current status, and future potential of minimally invasive glaucoma surgeries (MIGS), a significant advancement in the treatment of glaucoma, a leading cause of irreversible blindness. MIGS offer a less invasive alternative to traditional glaucoma surgeries, primarily aimed at reducing intraocular pressure, minimizing tissue trauma, and providing a safer profile. With the emergence of devices such as the Trabectome, iStent, and others, MIGS have expanded the surgical toolkit, allowing personalized, patient-centered care. Despite their advantages, MIGS face challenges such as efficacy in severe cases, long-term data, and accessibility. Ongoing research and technological innovations continue to refine their capabilities and applications, promising to further transform glaucoma management and patient outcomes. This paper provides an in-depth analysis of MIGS, reflecting on their impact and contemplating future directions in this dynamically evolving field.

Efficacy of preserved Tafluprost 0.0015% in lowering intraocular pressure

OBJECTIVE

To investigate the intraocular pressure (IOP) lowering effect of topical preserved tafluprost 0.0015% in a tertiary hospital setting in India.

METHODS

This is a retrospective chart review of patients with primary open-angle glaucoma (POAG) or ocular hypertension (OHT) attending regular outpatient visits in December 2019 and January 2021, and treated with topical preserved tafluprost 0.0015%. Based on their medication history, patients were divided into two groups, the "treatment naïve" group and the "switched" group, which included patients switched to tafluprost monotherapy after treatment with at least one prior drug.

RESULTS

The mean IOP of the study population reduced significantly from baseline level by 20.6% and 25.5% at 1 month and 3 months after preserved tafluprost 0.0015% treatment (P < 0.001 for both). The mean IOP in patients with only OHT reduced significantly from baseline level by 21% and 26% at 1 month and 3 months after preserved tafluprost 0.0015% treatment (P < 0.001 for both). The mean IOP in patients with POAG reduced significantly from baseline level by 19% and 24% at 1 month and 3 months after preserved tafluprost 0.0015% treatment (P < 0.001 for both). The baseline IOP ± SD in POAG treatment naïve patients was 25.3 ± 0.3 mmHg, which reduced significantly by 24% and 28% at 1 month and 3 months after preserved tafluprost 0.0015% treatment (P < 0.001 for both). The baseline IOP ± SD in POAG switched patients was 24.3 ± 0.1 mmHg, which reduced significantly by 18% and 22% at 1 month and 3 months after preserved tafluprost 0.0015% treatment (P < 0.001 for both). In the POAG switch group, the percent reduction in IOP at 3 months after preserved tafluprost 0.0015% treatment was 23% with timolol as first line, 22% with bimatoprost as first line, 20% with latanoprost as first line, and 19% with travoprost as first line (P < 0.001 for all).

CONCLUSIONS

We show significant IOP reduction with preserved tafluprost 0.0015% in a real-world setting. As first-line monotherapy in patients with OHT and in POAG-naïve patients, preserved tafluprost 0.0015% significantly reduced IOP at 3 months. Even as second-line therapy in nonresponders (POAG-Switched) to various drugs (same class [PGAs] versus different class), treatment with preserved tafluprost 0.0015% resulted in significant IOP reduction at 3 months.

Prediction of MIGS outcomes on second eyes using first eyes' response

To evaluate how well outcomes following cataract extraction and microinvasive glaucoma surgery in one eye predict outcomes in sequential second eye. Retrospective study of 78 patients who underwent cataract extraction and microinvasive glaucoma surgery in both eyes. Linear regressions using Pearson correlation coefficients were used to evaluate correlations in intraocular pressure and glaucoma medication change between eyes. Multivariable logistic regression models were used to evaluate the associations between first-eye variables and the likelihood of second-eye surgical success at 6 months. Surgical success was defined as meeting target intraocular pressure without additional medications compared to baseline or secondary surgical interventions. Baseline ocular characteristics were comparable between fellow eyes, with the majority having mild glaucoma. Intraocular pressure changes between fellow eyes at 6 months were modestly correlated between eyes (R = 0.48; P < .001). Changes in glaucoma medications were strongly correlated between eyes at all time points, and month 6 demonstrated the most significant correlation (R = 0.80; P < .001). First and second eye cohorts achieved 82% and 83% surgical success. Multivariate analysis for predictive factors of successful second eye surgery showed patients with successful first eye surgery at 6 months were significantly more likely to have successful second eye surgery (odds ratio, 20.67; P < .001). Reductions in intraocular pressure and glaucoma medications at 6 months following surgery in first eyes are correlated to second eye reductions. Successful surgical outcomes at 6 months following first eye surgeries are strongly associated with successful sequential second eye outcomes.

En face optical coherence tomography detection of Schlemm's canal in primary open angle glaucoma

Purpose: To compare the morphological characteristics of Schlemm's canal (SC) in patients with primary open-angle glaucoma (POAG) and healthy controls, using swept-source optical coherence tomography (SS-OCT) with en face reconstruction. Methods: In this Prospective comparative study, we included 100 eyes from 50 patients diagnosed with POAG and 50 healthy controls. Three-dimensional cube and line scans of the temporal and nasal quadrants of the anterior segment of the limbus were acquired using SS-OCT. SC was identified using en face and cross-sectional images. The diameter and area of SC in cross-sectional images and the visible percentage and area of SC in en face images were measured using ImageJ. Results: SC was observed in 84% of en face images and 81% of cross-sectional images in eyes with POAG but in 92% of en face images and 86% of cross-sectional images in control eyes. Significant differences between the POAG and normal control eyes were found in the en face area (0.35 ± 0.14 mm2 vs. 0.56 ± 0.22 mm2 in the temporal quadrant and 0.36 ± 0.14 mm2 vs. 0.58 ± 0.23 mm2 in the nasal quadrant; both p < 0.001) and visible percentage of SC (85.71% vs. 94.91% and 87.10% vs. 95.52% in the temporal and nasal quadrant respectively, both p < 0.001) in en face images as well as the cross-sectional area (2790.9 ± 942.2 μm2 vs. 4138.6 ± 2027.8 μm2 in the temporal quadrant and 2805.7 ± 947.2 μm2 vs. 4224.0 ± 2002.2 μm2 in the nasal quadrant, both p < 0.001) and diameter of SC (123.1 ± 25.4 μm vs. 149.5 ± 34.7 μm in the temporal quadrant and 126.3 ± 28.9 μm vs. 155.3 ± 36.0 μm in the nasal quadrant, both p < 0.001) in cross-section images. In addition, the mean intraocular pressure (IOP) significantly correlated with the en face area, visible percentage of SC, and cross-sectional area in the temporal and nasal quadrants. Conclusion: SS-OCT can obtain high-quality en face images of SC without post-acquisition processing. Eyes with POAG had a decreased en face SC area compared with normal eyes. A correlation between SC area, visible percentage of en face images, and IOP was also observed.

Primary Open Angle Glaucoma Diagnosis Using Pattern Electroretinogram Parameters

Background

Glaucoma is the most typical cause of permanent blindness. POAG, or primary open angle glaucoma, is the most common type. The pattern electroretinogram (PERG) has become a promising technique for detecting glaucoma early-on. The goal of this study was to assess the ability of PERG to diagnose POAG, especially in early, difficult-to-diagnose cases in comparison with other already established diagnostic methods.

Methods

150 participants (300 eyes) were enrolled in a cross-sectional study at ophthalmology department at Menoufia University Hospital in August 2022 to February 2023. All recruited participants underwent comprehensive ophthalmological and PERG exams. The studied eyes were divided into three groups as 100 normal eyes (Group I), 100 eyes with preperimetric glaucoma (Group II), and 100 eyes with established perimetric glaucoma (Group III).

Results

OCT-RNFL average thickness had a significant positive correlation with P50 latency (r=0.289, p=0.041) or P50 amplitude (r=0.302, p=0.018) and N95 amplitude (r=0.640, p=0.001) among group (II). Also, RNFL thickness had negative correlation with P50 amplitude (r= -0.268, p=0.043) among group (III). RNFL thickness and P50 and N95 amplitude showed highest AUC values in detecting preperimetric glaucomatous eyes vs normal eyes (AUC=0.927, 0.952, 904), and for detecting established perimetric glaucomatous eyes vs normal eyes (AUC=1.00, 0.957, 0.983 respectively) compared with VF MD which showed AUC (0.458 and 0.901 respectively).

Conclusion

Glaucoma patients exhibit PERG alterations (comparable to RNFL thickness changes) so, it could be used as an accurate diagnostic method in POAG. Because PERG alterations occur before visual field abnormalities, it could be relied on as an early diagnostic tool in preperimetric glaucoma. We can use both RNFL thickness assessment by OCT with PERG parameters as complementary tests for accurate diagnosis of preperimetric glaucoma which represents the most difficult diagnostic challenge in glaucoma diagnosis.

Relationships of Macular Functional Impairment With Structural and Vascular Changes According to Glaucoma Severity

Purpose

To determine the pointwise relationships of central visual field (VF) defects with macular ganglion cell loss and macular vessel density (VD) loss during various stages of glaucoma.

Methods

Eyes with primary open-angle glaucoma (POAG) were subjected to optical coherence tomography (OCT) and OCT angiography (OCTA) to evaluate macular ganglion cell layer (GCL) thickness and macular VD in the superficial and deep vascular complexes (SVC and DVC). OCT, OCTA, and VF locations were matched after correcting for retinal ganglion cell (RGC) displacement. Pointwise correlations of GCL thickness and VDs of the SVC and DVC with central VF sensitivity (VFS) were evaluated by Pearson's correlation analysis and compared in eyes with early and advanced POAG by Meng's test.

Results

Of the 100 eyes, 52 and 48 were classified as early and advanced POAG. Macular VD showed overall better correlation with central VFS than GCL thickness in both the early and advanced groups. SVC density showed the strongest correlation with central VFS in all groups (R = 0.327 in early group, R = 0.325 in advanced group, all P < 0.001). Although DVC density showed better correlation with VFS (R = 0.311) than GCL thickness (R = 0.212) in the early group (P < 0.001), the correlation was comparable in the advanced group (R = 0.199 and 0.176, respectively, P = 0.254).

Conclusions

After adjustment for RGC displacement, macular SVC density was better correlated with central VFS than macular GCL thickness in both early and advanced POAG. Macular DVC density showed better correlation with VFS than GCL thickness in early but not in advanced POAG, indicating that DVC loss may be involved in early central VF loss.

First-Generation iStent Bypass Implantation versus ab Externo Canaloplasty Combined with Phacoemulsification in Patients with Primary Open Angle Glaucoma-12-Month Follow-Up

This prospective, non-randomized, interventional clinical study evaluated the efficacy and safety profile of first-generation iStent bypass implantation versus ab externo canaloplasty, both combined with phacoemulsification, in patients with primary open-angle glaucoma (POAG) after 12-month follow-up. A total of 138 patients with POAG and their 138 eyes (69 phaco-iStent and 69 phacocanaloplasty) were included. Postoperatively at 12 months, the mean intraocular pressure (IOP) decreased from 18.44 ± 3.88 to 15.51 ± 2.50 mmHg and from 17.20 ± 4.04 to 14.97 ± 2.37 mmHg in the phaco-iStent (PiS) and phacocanaloplasty (PC) groups, respectively (p = 0.480). In both groups, 35.7% achieved >20% IOP reduction from baseline. A total of 86% and 71.4% of the eyes were medication-free at 12 months in the PiS and PC groups, respectively. In both groups, all eyes showed improvement in best-corrected visual acuity compared with baseline and demonstrated similar safety profiles throughout the 12-month follow-up period. This study showed equal hypotensive effects of PiS and PC. Both procedures significantly reduced the IOP and the requirement for IOP-lowering medications for at least 12 months postoperatively, with no significant differences between the groups.

Efficacy and safety of latanoprost/timolol fixed combination dosed twice daily compared to once daily in patients with primary open angle glaucoma

AIM

To evaluate whether latanoprost/timolol fixed combination (LTFC) dosed twice daily may provide further intraocular pressure (IOP) reduction and evaluate the safety profile at this dose.

METHODS

This is an open-labeled, randomized, prospective crossover study on fourty primary open angle glaucoma patients. Two weeks of washout period were followed by randomization to either once daily (OD, group A) or twice daily dosing (BD, group B) of LTFC for 4wk. After another 2-week washout period, the patients' treatment dose was crossed-over for another 4wk. IOP reduction alongside ocular and systemic side effects were evaluated.

RESULTS

Mean baseline IOP was 18.57±2.93 and 17.8±3.01 mm Hg before OD and BD dose respectively, (P=0.27). Mean IOP after BD dose was statistically lower (12.49±1.59 mm Hg) compared to OD (13.48±1.81 mm Hg, P=0.017). Although IOP reduction after BD dose was more (5.32±3.24 mm Hg, 29.89%) than after OD dosing (5.04 mm Hg, 27.14%), it did not reach statistical significance (P=0.68). Patients switched from OD to BD (group A) showed mean IOP reduction by 0.69 mm Hg [95% confidence interval (CI): -0.09 to 1.48 mm Hg, P=0.078]; but patients switched from BD to OD (group B) had significantly higher mean IOP by 1.25 mm Hg (95%CI: -2.04 to -0.46 mm Hg, P=0.006). BD dose had more ocular side effects albeit mild.

CONCLUSION

Mean IOP after LTFC dosed twice daily is statistically lower, with additional mild side effects.

The budget impact of introducing the OMNI® surgical system to a United States health plan for managing mild-to-moderate primary open-angle glaucoma

OBJECTIVES

Minimally invasive glaucoma surgery devices fill an unmet need in the treatment paradigm between topical intraocular pressure medicines and more invasive filtration procedures. This study evaluated the adoption of The OMNI® Surgical System with or without cataract surgery in primary open-angle glaucoma patients.

METHODS

A budget impact analysis estimated costs before and after adoption of OMNI® to a hypothetical US health plan with 1 million Medicare-covered lives over two years. Model input data were derived from published sources and development of the model included primary research with key opinion leaders and payers. The model compared total annual direct costs for OMNI® versus other treatment options (medications, other minimally invasive surgical procedures, selective laser trabeculoplasty) to calculate budget impact. A one-way sensitivity analysis was conducted to assess parameter uncertainty.

RESULTS

Increased adoption of OMNI® resulted in budget neutrality over the two years with a decrease in total costs of $35,362. Per member per month incremental costs were $0.00 when used without cataract surgery and yielded cost savings of -$0.01 when used with cataract surgery. Sensitivity analysis confirmed model robustness and identified surgical center fee variability as a key driver of costs.

CONCLUSION

OMNI® is budgetary efficient from a US payer perspective.

CCN2/CTGF tip the balance of growth factors towards TGF-β2 in primary open-angle glaucoma

TGF-β2 is the predominant TGF-β isoform within the eye. One function of TGF-β2 is to provide the eye with immune protection against intraocular inflammation. The beneficial function of TGF-β2 within the eye must be under tight control of a network of different factors. A disbalance of the network can result in different eye diseases. In Primary Open-Angle Glaucoma (POAG), one of the leading causes of irreversible blindness worldwide, TGF-β2 is significantly elevated in the aqueous humor and antagonistic molecules like BMPs are reduced. The changes provoke an altering of the quantity and quality of the extracellular matrix and the actin cytoskeleton in the outflow tissues, leading to an increased outflow resistance and thereby to an increased intraocular pressure (IOP), the major risk factor for primary open-angle glaucoma. The pathologic effect of TGF-β2 in primary open-angle glaucoma is mainly meditated by CCN2/CTGF. CCN2/CTGF can modulate TGF-β and BMP signaling by direct binding. The eye specific overexpression of CCN2/CTGF caused an increase in IOP and led to a loss of axons, the hallmark of primary open-angle glaucoma. CCN2/CTGF appears to play a critical role in the homeostatic balance of the eye, so we investigated if CCN2/CTGF can modulate BMP and TGF-β signaling pathways in the outflow tissues. To this end, we analyzed the direct effect of CCN2/CTGF on both signaling pathways in two transgenic mouse models with a moderate (βB1-CTGF1) and a high CCN2/CTGF (βB1-CTGF6) overexpression and in immortalized human trabecular meshwork (HTM) cells. Additionally, we investigate whether CCN2/CTGF mediates TGF-β effects via different pathways. We observed developmental malformations in the ciliary body in βB1-CTGF6 caused by an inhibition of the BMP signaling pathway. In βB1-CTGF1, we detected a dysregulation of the BMP and TGF-β signaling pathways, with reduced BMP activity and increased TGF-β signaling. A direct CCN2/CTGF effect on BMP and TGF-β signaling was shown in immortalized HTM cells. Finally, CCN2/CTGF mediated its effects on TGF-β via the RhoA/ROCK and ERK signaling in immortalized HTM cells. We conclude that CCN2/CTGF functions as a modulator of the homeostatic balance of BMP and TGF-β signaling pathways, which is shifted in primary open-angle glaucoma.

Combined Model of OCT Angiography and Structural OCT Parameters to Predict Paracentral Visual Field Loss in Primary Open-Angle Glaucoma

PURPOSE

To assess a model combining OCT angiography (OCTA) and OCT parameters to predict the severity of paracentral visual field (VF) loss in primary open-angle glaucoma (POAG).

DESIGN

Cross-sectional study.

PARTICIPANTS

Forty-four patients with POAG and 42 control subjects underwent OCTA and OCT imaging with a swept-source OCT device.

METHODS

The circumpapillary microvasculature was quantified for vessel density (cpVD) and flow (cpFlow) after delineation of Bruch's membrane opening and removal of large vessels. Retinal nerve fiber layer thickness (RNFLT) and Bruch's membrane opening-minimum rim width (BMO-MRW) were measured from structural OCT. Paracentral total deviation (PaTD) was defined as the average of the total deviation values within the central 10 degrees on Humphrey VF testing (24-2) for upper and lower hemifields. The OCT and OCTA parameters were measured in the affected hemisphere corresponding to the hemifield with lower PaTD for POAG patients. Models were created to predict affected PaTD based on RNFLT alone; RNFLT and BMO-MRW; OCTA alone; or RNFLT, BMO-MRW and OCTA parameters. The models were compared using coefficient of determination (r2) and Bayesian information criterion (BIC) score. Bayesian information criterion decrease of ≥6 indicates strong evidence for model improvement.

MAIN OUTCOME MEASURES

Performance of models containing OCT and OCTA parameters in predicting PaTD.

RESULTS

Patients with POAG and controls were similar in age and sex (65.9 ± 9.5 years and 38.4% male overall, P ≥ 0.56 for both). Average RNFLT, minimum RNFLT, average BMO-MRW, minimum BMO-MRW, cpVD, and cpFlow were all significantly lower (all P < 0.001) in the affected hemisphere in patients with POAG than in controls. In patients with POAG, the average mean deviation was -4.33 ± 3.25 dB; the PaTD of the affected hemifield averaged -4.55 ± 5.26 dB and correlated significantly with both OCTA and structural OCT parameters (r ≥ 0.43, P ≤ 0.004 for all). The model containing RNFLT, BMO-MRW, and OCTA parameters was superior in predicting affected PaTD (r2 = 0.47, BIC = 290.7), with higher r2 and lower BIC compared with all 3 other models.

CONCLUSIONS

A combined model of OCTA and structural OCT parameters can predict the severity of paracentral VF loss of the affected hemifield, supporting clinical utility of OCTA in patients with POAG with paracentral VF loss.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.

Amsler Grid Versus 10-2 Test in Primary Open Angle Glaucoma

Background

Glaucoma is the leading cause of global irreversible blindness. The goal of management in glaucoma lies in its early detection and treatment to prevent further optic neuropathy. Available equipment for early glaucoma detection is not cost-effective or readily available in resource-scarce settings such as Nigeria. Thus, there is a need for a simple cost-effective tool to detect glaucomatous central visual field (CVF) defects in all the stages of glaucoma within the community in resource scarce-settings.

Aims and Objectives

The aim of this article is to determine the validity of the Amsler grid in detecting central glaucomatous visual field defects in primary open angle glaucoma (POAG).

Materials and Methods

This was a cross-sectional study of follow-up glaucoma patients at a secondary eye care hospital in Nigeria. All patients had detailed ophthalmic examination in addition to 24-2 and 10-2 CVF tests and Amsler grid test. POAG was classified using the Hodapp-Parrish-Anderson criteria into mild, moderate, and severe on 24-2 CVF. The diagnostic validity of the Amsler grid was calculated using the 10-2 CVF as a reference standard. Regression analyses were performed between the Amsler grid scotoma area and 10-2 CVF parameters [mean deviation (MD), scotoma extent (SE), and scotoma mean depth (SMD)].

Results

A total of 150 eyes of 150 patients were enrolled. The sensitivity, specificity, and positive predictive value and negative predictive value of the Amsler grid compared with the 10-2 CVF was 49.5%, 95.9%, 96.2%, and 47.9%, respectively, with an area under curve of 0.7. Sensitivity increased with increasing severity (P < 0.001) from 20.0%, 31.0%, and 76.6% in mild, moderate, and severe POAG, respectively. The Amsler grid scotoma area had the strongest relationship with the 10-2 MD, followed by 10-2 SE and 10-2 SMD with a quadratic R2 of 0.579, 0.370, and 0.307, respectively.

Conclusion

The Amsler grid has a low sensitivity in mild-to-moderate POAG. However, it may serve as an adjunctive tool in resource-scarce settings for detection of severe POAG in the community by primary eye care providers.

Glaucoma and Myopia: Diagnostic Challenges

The rising global prevalence of myopia is a growing concern for clinicians, as it predisposes patients to severe ocular pathologies including glaucoma. High myopia can be associated with clinical features that resemble glaucomatous damage, which make an accurate glaucoma diagnosis challenging, particularly among patients with normal intraocular pressures. These patients may also present with established visual field defects which can mimic glaucoma, and standard imaging technology is less useful in disease detection and monitoring due to the lack of normative data for these anatomically unique eyes. Progression over time remains the most critical factor in facilitating the detection of early glaucomatous changes, and thus careful longitudinal follow-up of high-risk myopic patients is the most important aspect of management. Here, we review our current understanding of the complex relationship between myopia and glaucoma, and the diagnostic challenges and limitations of current testing protocols including visual field, intraocular pressure, and imaging. Furthermore, we discuss the clinical findings of two highly myopic patients with suspected glaucoma.

Efficacy and Safety of Deep Sclerectomy With the Esnoper Clip Implant for Uncontrolled Primary Open Angle Glaucoma: A 1 Year Prospective Study

PRCIS

Deep sclerectomy (DS) with the Esnoper Clip drainage implant in patients with uncontrolled primary open angle glaucoma (POAG) achieved a complete success rate of 87.2% at the 1-year follow-up.

PURPOSE

To investigate the efficacy and safety of DS followed by Esnoper Clip implantation in patients with uncontrolled POAG.

MATERIALS AND METHODS

In a prospective, consecutive, interventional study, we investigated 39 eyes of 35 patients with uncontrolled POAG who underwent DS with Esnoper Clip implantation. Complete ophthalmologic examinations including corrected visual acuity and intraocular pressure (IOP), were performed preoperatively, and at 1 day, at 1 week as well as at 1, 3, 6, 9, and 12 months postoperatively. Moreover, any goniopunctures and glaucoma medications required postoperatively were noted.

RESULTS

The mean preoperative IOP was 20.8±5.2 mm Hg and it decreased to 13.9±3.1 mm Hg at 1 year postoperatively ( P <0.001). The number of glaucoma medications decreased from 2.9±0.7 preoperatively to 0.3±0.8 after 1 year ( P <0.001). The complete success rate (IOP≤21 mm Hg without glaucoma medication) and the qualified success rate (IOP ≤21 mm Hg with or without glaucoma medication) were 87.2% and 94.9%, respectively. Goniopuncture was performed in 33.3% of cases. No significant corrected visual acuity changes were registered at the final follow-up. Perioperative complications consisted of 3 micro-perforations of the trabeculo-descemet membrane. Postoperative complications included: hyphema (6 eyes), hypotony (6 eyes), shallow anterior chamber (3 eyes), choroidal detachment (4 eyes)-all of which were resolved without surgical intervention during the first postoperative month-and conjunctival dehiscence, which required resuture (2 eyes).

CONCLUSION

Deep sclerectomy with the Esnoper Clip implant was safe and effectively lowered IOP in patients with uncontrolled POAG.

Genome-wide association study finds multiple loci associated with intraocular pressure in HS rats

Elevated intraocular pressure (IOP) is influenced by environmental and genetic factors. Increased IOP is a major risk factor for most types of glaucoma, including primary open angle glaucoma (POAG). Investigating the genetic basis of IOP may lead to a better understanding of the molecular mechanisms of POAG. The goal of this study was to identify genetic loci involved in regulating IOP using outbred heterogeneous stock (HS) rats. HS rats are a multigenerational outbred population derived from eight inbred strains that have been fully sequenced. This population is ideal for a genome-wide association study (GWAS) owing to the accumulated recombinations among well-defined haplotypes, the relatively high allele frequencies, the accessibility to a large collection of tissue samples, and the large allelic effect size compared to human studies. Both male and female HS rats (N = 1,812) were used in the study. Genotyping-by-sequencing was used to obtain ∼3.5 million single nucleotide polymorphisms (SNP) from each individual. SNP heritability for IOP in HS rats was 0.32, which agrees with other studies. We performed a GWAS for the IOP phenotype using a linear mixed model and used permutation to determine a genome-wide significance threshold. We identified three genome-wide significant loci for IOP on chromosomes 1, 5, and 16. Next, we sequenced the mRNA of 51 whole eye samples to find cis-eQTLs to aid in identification of candidate genes. We report 5 candidate genes within those loci: Tyr, Ctsc, Plekhf2, Ndufaf6 and Angpt2. Tyr, Ndufaf6 and Angpt2 genes have been previously implicated by human GWAS of IOP-related conditions. Ctsc and Plekhf2 genes represent novel findings that may provide new insight into the molecular basis of IOP. This study highlights the efficacy of HS rats for investigating the genetics of elevated IOP and identifying potential candidate genes for future functional testing.

Genetic Factors Implicated in the Investigation of Possible Connections between Alzheimer's Disease and Primary Open Angle Glaucoma

Both Alzheimer's disease (AD) and primary open angle glaucoma (POAG) are diseases of primary global neurodegeneration with complex pathophysiologies. Throughout the published literature, researchers have highlighted similarities associated with various aspects of both diseases. In light of the increasing number of findings reporting resemblance between the two neurodegenerative processes, scientists have grown interested in possible underlying connections between AD and POAG. In the search for explanations to fundamental mechanisms, a multitude of genes have been studied in each condition, with overlap in the genes of interest between AD and POAG. Greater understanding of genetic factors can drive the research process of identifying relationships and elucidating common pathways of disease. These connections can then be utilized to advance research as well as to generate new clinical applications. Notably, AD and glaucoma are currently diseases with irreversible consequences that often lack effective therapies. An established genetic connection between AD and POAG would serve as the basis for development of gene or pathway targeted strategies relevant to both diseases. Such a clinical application could be of immense benefit to researchers, clinicians, and patients alike. This paper aims to summarize the genetic associations between AD and POAG, describe common underlying mechanisms, discuss potential areas of application, and organize the findings in a review.

The Far Nasal Part of the Field of Vision - Part II. Contribution to the Timely Diagnosis of Glaucoma

AIM

The aim of this study was to examine possible changes in the conventionally undiagnosed nasal visual field in patients diagnosed with early primary open angle glaucoma.

MATERIAL AND METHODS

Examination of the far nasal part of the visual field was performed in 30 patients (60 eyes) with early stage of primary open angle glaucoma (preperimetric stage of changes). The cohort consisted of 16 women (mean age 46.5 years) and 14 men (mean age 44.7 years). In all eyes, the glaucoma program (rapid threshold program of 50 degrees nasally and 22 degrees temporally) was performed with the Medmont M700 instrument to determine the physiological visual field. Visual acuity was 1.0 with a possible correction less than or equal to ±3 diopters and they had no other ocular defect except glaucoma disease. The visual field was subsequently examined with the same instrument by moving the fixation point 40 degrees temporally (spatially adaptive program) and simultaneously turning the head 10 degrees nasally. A total of 89 examination points were included using flicker stimuli and a range of 0-120 degrees nasally.

RESULTS

The far nasal limit of the visual field reached 100° in 13.33% of eyes, 105° in 20% of eyes and up to 110° in 66.67% of eyes.

CONCLUSION

In all eyes, depression of the distal periphery of the nasal part of the visual field was found to range from 50 to 95 degrees, with a normal visual field examined by the glaucoma program.

Roles of Toric intraocular Lens implantation on visual acuity and astigmatism in glaucomatous eyes treated with iStent and cataract surgery

Background

To assess the efficacy of toric intraocular lenses (IOLs) in combined cataract and minimally invasive glaucoma surgery (MIGS), visual and refractive outcomes were compared between eyes implanted with non-toric and toric IOLs during iStent triple procedures.

Methods

In this retrospective study, open angle glaucoma eyes with preexisting corneal astigmatism of -1.5 diopter (D) or more and implanted with non-toric (n = 9) or toric (n = 9) IOLs were included. The main outcome measures were the intergroup difference in the uncorrected visual acuity (UCVA) and refractive astigmatism at 3 months postoperatively.

Results

Preoperatively, the logarithm of the minimum angle of resolution (logMAR) UCVAs and refractive astigmatism were equivalent between the groups. Postoperatively, the logMAR UCVA (non-toric, 0.45 ± 0.31; toric, 0.14 ± 0.15; P = 0.021) was significantly better and the refractive astigmatism (non-toric, -2.03 ± 0.63 D; toric, -0.67 ± 0.53 D; P = 0.0014) significantly less in the toric group. The toric group had postoperative improvements in the logMAR UCVA (-0.21, P = 0.020) and refractive astigmatism (+ 1.72 D, P = 0.0039). Vector analyses showed the postoperative centroid magnitude and confidence eclipses of refractive astigmatism was less in the toric group (0.47 D at 173°±0.73D) than the non-toric group (1.10 D at 2°±1.91D). Postoperatively, 78% of eyes in the toric group had 1.0 D or less refractive astigmatism compared with 11% in the non-toric group. Surgically induced astigmatism (non-toric, 0.18 D at 65°; toric, 0.29 D at 137°) did not differ between groups.

Conclusion

Use of toric IOLs is a reasonable option for better visual outcomes when the combined cataract and iStent surgery is performed in glaucomatous eyes with corneal astigmatism.

Intraocular Pressure Fluctuation in Primary Open-Angle Glaucoma with Canaloplasty and Microcatheter Assisted Trabeculotomy

Background: Schlemm’s canal (SC) targeted procedures constitute a promising therapy for open angle glaucoma (POAG), safer and less invasive. However, little attention was paid to the intraocular pressure (IOP) variation in patients receiving these procedures, which is the risk factor for POAG progression. This study is to evaluate the IOP variation in eyes with POAG after modified canaloplasty (MC) and microcatheter assisted trabeculotomy (MAT). (2) Methods: POAG with good IOP in office hours after MC or MAT and age-matched normal subjects were recruited in this prospective coherent study. IOP in sitting and supine positions and 24-h IOP was measured. Aqueous vein and blood reflux into the SC were examined. (3) Results: Among 20 normal subjects, 25 eyes with MC eyes and 30 eyes with MAT were recruited in this study. Aqueous veins are frequently located in the inferior nasal quadrants in all groups. No pulsatile signs were observed in an aqueous vein in the MAT group but they were observed in 68% of the MC group. Blood reflux in the SC could be seen in all the operated eyes. The IOP in the sitting position was not significant different among groups (p = 0.419). Compared to normal, the IOP increased dramatically after lying down for 5 min in the MC and MAT groups (PMC vs. normal = 0.003, PMAT vs. normal = 0.004), which is similar for IOP change after lying down for 60 min (PMC vs. normal < 0.001, PMAT vs. normal < 0.001). In terms of diurnal IOP, subjects were stable in the MAT group (p < 0.01), variable in the normal group (p = 0.002), and most fluctuant in MC group (p < 0.001). (4) Conclusions: MC and MAT reduce the IOP but present aberrant short-term IOP regulation, which should be paid attention to in clinical settings.

Personal Computer-Based Visual Field Testing as an Alternative to Standard Automated Perimetry

Introduction Standard automated perimetry (SAP) is the gold standard of visual field assessment in patients with neuro-ophthalmic conditions. Glaucoma is a progressive optic neuropathy characterized by damage to the ganglion cell complex with corresponding visual field defects and intraocular pressure (IOP) being the only modifiable ocular risk factor. Recent advances in technology have paved the way for remote screening and monitoring of visual field defects with the aid of a computer or tablet-based software. One such personal computer (PC)-based software is 'Specvis', which has shown promising reliability as compared to SAP. The primary objective of this study was to compare Specvis and Humphrey Field Analyzer (HFA) visual field reports in the graphical domain while secondary objectives were to estimate the ease of use of Specvis in comparison to HFA and comparison of test duration between Specvis and HFA.  Materials and methods This was a cross-sectional validation study performed at a tertiary care ophthalmology institute in Rawalpindi, Pakistan. Subjects presenting to the outpatient department were recruited based on consecutive sampling technique and were divided into healthy and diseased groups. Basic data collection instrument after informed consent was filled with demographic data, ophthalmic data, disease condition, and attached with analysis reports of both HFA and Specvis for assessment by three senior ophthalmology consultants independently. A total of 218 eyes of 109 subjects were included in this pilot study. SAP was done on the VF 30-2 program using HFA 3. The same patient then performed the visual field assessment on a PC with Specvis installed and settings adjusted to match the VF 30-2 program of HFA as closely as possible. Visual fields of a subject obtained from HFA and Specvis were then coupled and sent to three different senior ophthalmologists. The assessment was done by comparing the greyscale visual field printouts in the graphical domain and scored based on a 5-point Likert scale which were then analyzed for inter-observer reliability. After each test, all subjects were asked to rate the difficulty level of performing the test on HFA and Specvis based on a 5-point Likert scale. The duration of the test performed on HFA and Specvis was also noted for comparison. Results We observed male preponderance in our study participants (n=128, 58.72%). The majority of the participants were non-diseased (n=170, 77.98%) while advanced glaucoma was the commonest disease in the diseased group (n = 22, 10.09%). The mean age of the participants was 40.71 (SD=15.24). The observations for the HFA test duration had an average of 213.33 seconds (SD=33.49, Min=174.00, Max=314.00) while the Specvis test duration had an average of 267.36 seconds (SD=35.98, Min=228.00, Max=370.00). A significant positive correlation was observed between score 1, score 2, and score 3 given by the three ophthalmologists. A significant negative correlation was observed between ease of using HFA and age, with a correlation of -.28. A significant negative correlation was also observed between ease of using Specvis and age. Conclusion Specvis, a computer-based free open-source software used in our study, can give promising results in diagnosing as well as monitoring the progression of visual field defects. It can act as a significantly cost-effective and readily available bridge between visual field examination by confrontation method and SAP.

Corneal endothelium, retinal nerve fiber layer, ganglion cell complex, and perimetry measurements in normal eyes and those with primary open-angle glaucoma

Background

Corneal endothelial cell (CEC) loss in glaucoma can be attributed to the direct compressive effect of elevated intraocular pressure. Herein, we aimed to evaluate specular microscopic changes in CEC count and morphology in correlation to retinal nerve fiber layer (RNFL) changes detected by spectral-domain optical coherence tomography (SD-OCT) in early and advanced primary open-angle glaucoma (POAG).

Methods

This descriptive-analytical study involved patients with medically controlled POAG versus non-glaucomatous patients of the same age group. Specular microscopy, visual field testing, and SD-OCT of the RNFL and macular ganglion cell complex (GCC) were performed. Eyes with POAG were further subcategorized into early and advanced stages.

Results

The study included 130 eyes of 130 participants; 70 were eyes with POAG (40 eyes with early-stage POAG, 30 eyes with advanced-stage POAG), and 60 were healthy eyes. The groups were comparable regarding mean age and sex. No significant difference was found in corneal parameters between healthy eyes, eyes with early POAG, and eyes with advanced POAG (all P > 0.05). In eyes with early-stage POAG, a significant negative correlation was found between the coefficient of variation (CV) and superior RNFL thickness (r = - 0.5; P = 0.018), and between the percentage of hexagonal cells (hexagonality) and vertical cup-to-disc ratio (r = - 0.43; P = 0.035). A significant positive correlation was found between hexagonality and superior as well as inferior RNFL thickness (r = + 0.53; P = 0.008 and r = + 0.50; P = 0.015, respectively). However, in the advanced glaucomatous eyes, no significant correlation was found between RNFL thickness and CEC parameters.

Conclusions

CEC parameters were not affected in eyes with early or advanced POAG compared with healthy eyes, despite a significant thinning of RNFL and macular GCC. In eyes with early-stage POAG, a significant correlation was found between morphological characteristics of CECs, such as CV and hexagonality, with superior and inferior RNFL thickness in the optic nerve head on SD-OCT images. Future longitudinal studies with larger sample sizes are needed to verify our results.

Short-term surgical outcomes of twin-site combined phaco-emulsification and mitomycin-C augmented trabeculectomy in pseudo-exfoliation glaucoma versus primary open-angle glaucoma

Purpose

To compare the short-term outcomes of combined phaco-emulsification with posterior chamber intra-ocular lens and mitomycin augmented trabeculectomy in patients with pseudo-exfoliation glaucoma (PXFG) versus primary open-angle glaucoma (POAG).

Methods

A total of 144 eyes of 144 patients were enrolled in this prospective interventional comparative study, 72 each of which had PXFG and POAG, respectively. All patients underwent twin-site combined phaco-trabeculectomy at a tertiary eye center in India between December 2017 and December 2018 and were followed up for a period of 12 months. The main outcome measures were intra-ocular pressure (IOP), best corrected visual acuity (BCVA), total surgical time, rate of intra-operative and post-operative complications, and the number of ocular hypotensive medications needed. Success rates were determined via Kaplan-Meier survival analysis.

Results

The mean age was 63.9 ± 7.9 years in the POAG group and 66.4 ± 6.8 years in the PXFG group (P - 0.04). The baseline BCVA, IOP, and cup-disc ratio were comparable between two groups. Intra-operative complications and post-operative outcomes were comparable between the two groups. There was a significant drop in anti-glaucoma medications in both groups. Six patients, three (4.2%) in each group, were lost to follow-up after 6 months. Three patients (4.2%) in PXFG needed additional glaucoma intervention for controlling IOP, one patient needed a non-valved glaucoma drainage device, and two patients required diode cyclo-photocoagulation within the follow-up period.

Conclusion

Patients with PXFG had a longer surgical time than POAG. Similar success and complication rates were observed following combined twin-site phaco-trabeculectomy in both POAG and PXFG at 1 year. Combined glaucoma surgery resulted in good IOP control, improvement in BCVA, and lower requirement of ocular hypotensives in both the groups.

Optical coherence tomography evaluation of retinal nerve fiber layer thickness in non-arteritic anterior ischemic optic neuropathy and primary open angle glaucoma: a systematic review and Meta-analysis

AIM

To assess the differences in average and sectoral peripapillary retinal nerve fiber layer (pRNFL) thickness using spectral domain optical coherence tomography (SD-OCT) in patients with non-arteritic anterior ischemic neuropathy (NAION) compared with those with primary open angle glaucoma (POAG).

METHODS

A comprehensive literature search of the PubMed, Cochrane Library, and Embase databases were performed prior to October, 2021. Studies that compared the pRNFL thickness in NAION eyes with that in POAG eyes with matched mean deviation of the visual fields were included. The weighted mean difference (WMD) with 95% confidence interval (CI) was used to pool continuous outcomes.

RESULTS

Ten cross-sectional studies (11 datasets) comprising a total of 625 eyes (278 NAION eyes, 347 POAG eyes) were included in the qualitative and quantitative analyses. The pooled results demonstrated that the superior pRNFL was significantly thinner in NAION eyes than in POAG eyes (WMD=-6.40, 95%CI: -12.22 to -0.58, P=0.031), whereas the inferior pRNFL was significant thinner in POAG eyes than in NAION eyes (WMD=11.10, 95%CI: 7.06 to 15.14, P≤0.001). No difference was noted concerning the average, nasal, and temporal pRNFL thickness (average: WMD=1.45, 95%CI: -0.75 to 3.66, P=0.196; nasal: WMD=-2.12, 95%CI: -4.43 to 0.19, P=0.072; temporal: WMD=-1.24, 95%CI: -3.96 to 1.47, P=0.370).

CONCLUSION

SD-OCT based evaluation of inferior and superior pRNFL thickness can be potentially utilized to differentiate NAION from POAG, and help to understand the different pathophysiological mechanisms between these two diseases. Further longitudinal studies and studies using eight-quadrant or clock-hour classification method are required to validate the obtained findings.

Bioinformatic Prioritization and Functional Annotation of GWAS-Based Candidate Genes for Primary Open-Angle Glaucoma

Background: Primary open-angle glaucoma (POAG) is the most prevalent glaucoma subtype, but its exact etiology is still unknown. In this study, we aimed to prioritize the most likely ‘causal’ genes and identify functional characteristics and underlying biological pathways of POAG candidate genes. Methods: We used the results of a large POAG genome-wide association analysis study from GERA and UK Biobank cohorts. First, we performed systematic gene-prioritization analyses based on: (i) nearest genes; (ii) nonsynonymous single-nucleotide polymorphisms; (iii) co-regulation analysis; (iv) transcriptome-wide association studies; and (v) epigenomic data. Next, we performed functional enrichment analyses to find overrepresented functional pathways and tissues. Results: We identified 142 prioritized genes, of which 64 were novel for POAG. BICC1, AFAP1, and ABCA1 were the most highly prioritized genes based on four or more lines of evidence. The most significant pathways were related to extracellular matrix turnover, transforming growth factor-β, blood vessel development, and retinoic acid receptor signaling. Ocular tissues such as sclera and trabecular meshwork showed enrichment in prioritized gene expression (>1.5 fold). We found pleiotropy of POAG with intraocular pressure and optic-disc parameters, as well as genetic correlation with hypertension and diabetes-related eye disease. Conclusions: Our findings contribute to a better understanding of the molecular mechanisms underlying glaucoma pathogenesis and have prioritized many novel candidate genes for functional follow-up studies.

Detection of Intraocular Hypertension during Opportunity Screening (Check-Up Medical Inspections)

The aim of the study is the early detection of OHT (Ocular hypertension) in patients, in the activity of secondary prophylaxis (opportunity screening-medical check-up), to prevent blindness caused by POAG (Primary Open Angle Glaucoma). In Romania, medical examination of personnel with responsibilities in Transport Safety (TS) is legally regulated, being mandatory as a result of the internal transposition of European legislation in the field. The addressability of the patients for examination was determined by personal choice, depending on the accessibility of the medical service on the profile market (availability and price). The design of the study is epidemiological, observational, descriptive and retrospective. The standardized medical protocol included: personal medical history (anamnesis), physical ophthalmological examination, Intraocular pressure (IOP) measurement and Visual Field (VF) performance, with Automated Perimeter “Optopol PTS 910” through “Fast Threshold” strategy. The specialized medical research was completed with a dichotomous questionnaire entitled “Symptom Inventory”, made according to the recommendations of patients resulting from “Focus group” research. The study was carried out within the “Check-up” type medical controls upon request, only for personnel with positions in Transport Safety (TS), during January−December 2021 at S.C. ARTIMED S.R.L. Oradea, Bihor County. Health analysis was performed for 820 people, of whom 71 people (8.65%) tested positive for IOP > 21 mmHg, (suspected OHT) compared to 749 (91.35%) with normal values (Normal intraocular pressure-NIOP); the two lots being statistically significantly different (x2 = 560.590, df = 1, p = 0.000). The study involved 754 men (92.0%) and 66 women (8.0%), the sex ratio is 11.42 (Exp (B) = 0.782, Sig = 0.558, 95% CI = 0.343−1783; sex is not a significant predictor at the 5% level). The prevalence of OHT was 8.66% for the whole group, 8.48% for men and 10.60% for women. In the screening action for the whole group of patients the following was determined: IOP reference = 20.85 mmHg, Sensitivity (Se) = 91.5% and 1-Specificity (Sp) = 0.073, (Sp = 92.7%). The predictive value of the screening test was: Positive Predictive Value (PPV) = 90.1% and Negative Predictive Value (NPV) = 91.7%; Area under the ROC Curve (Receiver Operating Characteristic) = 0.986, Sig. = 0.000, CI95% = 0.979−0.993. A binary logistical model of a questionnaire was developed to determine the screening parameters which significantly predicted OHT: IOP (OR = 4.154, 95% CI: 3.155−5.469), Age < 40 years (OR = 0.408, 95% CI: 0.239−0.698) and Pattern Defect (PD) (OR = 1.475% CI: 1.130−1.925). The results of this study assess health status through regular medical examinations, and highlight their importance and usefulness in secondary prevention activity. The particularity of this “check-up” type for personnel with attributions in transport safety is based on two essential aspects: the legal obligation to perform it and the fact it is financed by the beneficiary (the employer). In patients suspected of OHT after antiglaucoma treatment, IOP statistically significantly decreased.

Asian Race and Primary Open-Angle Glaucoma: Where Do We Stand?

Primary open-angle glaucoma (POAG) is an optic neuropathy characterized by irreversible retinal ganglion cell damage and visual field loss. The global POAG prevalence is estimated to be 3.05%, and near term is expected to significantly rise, especially within aging Asian populations. Primary angle-closure glaucoma disproportionately affects Asians, with up to four times greater prevalence of normal-tension glaucoma reported compared with high-tension glaucoma. Estimates for overall POAG prevalence in Asian populations vary, with Chinese and Indian populations representing the majority of future cases. Structural characteristics associated with glaucoma progression including the optic nerve head, retina, and cornea are distinct in Asians, serving as intermediates between African and European descent populations. Patterns in IOP suggest some similarities between races, with a significant inverse relationship between age and IOP only in Asian populations. Genetic differences have been suggested to play a role in these differences, however, a clear genetic pattern is yet to be established. POAG pathogenesis differs between Asians and other ethnicities, and it may differ within the broad classification of the Asian race. Greater awareness and further research are needed to improve treatment plans and outcomes for the increasingly high prevalence of normal tension glaucoma within aging Asian populations.

A Role of Caveolae in Trabecular Meshwork Mechanosensing and Contractile Tone

Polymorphisms in the CAV1/2 gene loci impart increased risk for primary open-angle glaucoma (POAG). CAV1 encodes caveolin-1 (Cav1), which is required for biosynthesis of plasma membrane invaginations called caveolae. Cav1 knockout mice exhibit elevated intraocular pressure (IOP) and decreased outflow facility, but the mechanistic role of Cav1 in IOP homeostasis is unknown. We hypothesized that caveolae sequester/inhibit RhoA, to regulate trabecular meshwork (TM) mechanosensing and contractile tone. Using phosphorylated myosin light chain (pMLC) as a surrogate indicator for Rho/ROCK activity and contractile tone, we found that pMLC was elevated in Cav1-deficient TM cells compared to control (131 ± 10%, n = 10, p = 0.016). Elevation of pMLC levels following Cav1 knockdown occurred in cells on a soft surface (137 ± 7%, n = 24, p < 0.0001), but not on a hard surface (122 ± 17%, n = 12, p = 0.22). In Cav1-deficient TM cells where pMLC was elevated, Rho activity was also increased (123 ± 7%, n = 6, p = 0.017), suggesting activation of the Rho/ROCK pathway. Cyclic stretch reduced pMLC/MLC levels in TM cells (69 ± 7% n = 9, p = 0.002) and in Cav1-deficient TM cells, although not significantly (77 ± 11% n = 10, p = 0.059). Treatment with the Cav1 scaffolding domain mimetic, cavtratin (1 μM) caused a reduction in pMLC (70 ± 5% n = 7, p = 0.001), as did treatment with the scaffolding domain mutant cavnoxin (1 μM) (82 ± 7% n = 7, p = 0.04). Data suggest that caveolae differentially regulate RhoA signaling, and that caveolae participate in TM mechanotransduction. Cav1 regulation of these key TM functions provide evidence for underlying mechanisms linking polymorphisms in the Cav1/2 gene loci with increased POAG risk.

The RNA-binding protein and stress granule component ATAXIN-2 is expressed in mouse and human tissues associated with glaucoma pathogenesis

Polyglutamine repeat expansions in the Ataxin-2 (ATXN2) gene were first implicated in Spinocerebellar Ataxia Type 2, a disease associated with degeneration of motor neurons and Purkinje cells. Recent studies linked single nucleotide polymorphisms in the gene to elevated intraocular pressure in primary open angle glaucoma (POAG); yet, the localization of ATXN2 across glaucoma-relevant tissues of the vertebrate eye has not been thoroughly examined. This study characterizes ATXN2 expression in the mouse and human retina, and anterior eye, using an antibody validated in ATXN2^-/- retinas. ATXN2-ir was localized to cytosolic sub compartments in retinal ganglion cell (RGC) somata and proximal dendrites in addition to GABAergic, glycinergic, and cholinergic amacrine cells in the inner plexiform layer (IPL) and displaced amacrine cells. Human, but not mouse retinas showed modest immunolabeling of bipolar cells. ATXN2 immunofluorescence was prominent in the trabecular meshwork and pigmented and nonpigmented cells of the ciliary body, with analyses of primary human trabecular meshwork cells confirming the finding. The expression of ATXN2 in key POAG-relevant ocular tissues supports the potential role in autophagy and stress granule formation in response to ocular hypertension.

PRIMARY OPEN-ANGLE GLAUCOMA DUE TO MUTATIONS IN THE MYOC GENE

AIM

Mutations in the myocilin gene (MYOC) cause trabecular dysfunction and thus are involved in the pathogenesis of primary open-angle glaucoma (POAG). The aim of this study was to characterize and describe the clinical findings in two Czech families with POAG due to pathogenic variants in the MYOC gene.

MATERIAL AND METHODS

Members of the two families affected by POAG underwent complete ophthalmological examination. In the proband from the first family, a direct sequencing of the three most frequent mutations in the MYOC gene was performed, and in the proband from the second family, an exome sequencing was performed. Other family members underwent targeted tests using direct sequencing.

RESULTS

In total, 10 individuals diagnosed with POAG aged 20-70 years (mean 32.2 years, SD ±10,9 years) were examined. Eight of them showed advanced glaucomatous neuropathy with severe changes in the retinal nerve fiber layer. Clinical signs of POAG were present in six individuals in the third decade of life already; another four developed POAG during the fourth decade of life. Eight out of 10 patients had to undergo filtration surgery. Surgery was performed within 1 to 7 years of diagnosis, but mostly was performed within 2 years of glaucoma diagnosis. In the first family, MYOC variant c.1099G&gt;A p.(Gly367Arg) was shown in the affected family members; in the second family MYOC variant c.1440C&gt;A p.(Asn480Lys), both in heterozygous state. The changes were assessed as pathogenic.

CONCLUSION

Our study is the first to describe mutations in the MYOC gene causing POAG in Czech patients. Genetic testing may be recommended for this diagnosis, especially in individuals with early presentation and a positive family history. Carriers of pathogenic variants of the MYOC gene have a lifetime risk of developing POAG of more than 50% and the course of their disease is often more aggressive, requiring surgical intervention to permanently control the intraocular pressure.

The Value of Annual Glaucoma Screening for High-Risk Adults Ages 60 to 80

Glaucoma will increase in significance as a public health problem over the next three decades as the size of the aging US population grows more significant. Because glaucoma is more prevalent among African-Americans and Hispanics, and these groups will soon outnumber Caucasians. Therefore, it is even more imperative that a referral for screening protocol for high-risk groups be implemented as the standard of care. At least half of those with glaucoma do not know they have it, and the impact on the quality of life for those whose glaucoma progresses to visual impairment or blindness is significant. Without screening, glaucoma is likely to burden many families, particularly the underserved and society, unduly. Education for the public, those at increased risk, and their physicians about glaucoma, the importance of objective screening, and early treatment even for those with no symptoms will be critical toward the success of any screening protocol.

Evaluation of the Efficacy and Safety of Canaloplasty and iStent Bypass Implantation in Patients with Open-Angle Glaucoma: A Review of the Literature

The aim of the paper was to evaluate the efficacy and safety of minimally invasive antiglaucoma procedures: Canaloplasty and iStent bypass implantation with and without phacoemulsification in patients with primary open-angle glaucoma (POAG). A systematic review of the recent literature was performed based on the PubMed, Google Scholar, Web of Science and Scopus databases. The effectiveness of the procedures was evaluated based on the reduction of intraocular pressure (IOP) and the amount of antiglaucoma medication used before and after surgery. Safety of the treatments was evaluated based on the number of incidences of certain intraoperative and postoperative complications. Independent prospective randomized controlled trials (PRCTs) have demonstrated that both procedures, canaloplasty and iStent implantation, are effective in reducing IOP and the amount of antiglaucoma medication. Considering the safety profile of these procedures, both canaloplasty and iStent implantation are associated with low rates of postoperative complications and have similar safety profiles. Further studies are needed to confirm the results of our analysis, including a high-quality randomized controlled trial comparing canaloplasty and iStent bypass implantation

Fundamental Biomaterial Considerations in the Development of a 3D Model Representative of Primary Open Angle Glaucoma

Glaucoma is a leading cause of irreversible blindness globally, with primary open angle glaucoma (POAG) being the most common subset. Raised intraocular pressure is an important risk factor for POAG and is caused by a reduction in aqueous humour (AqH) outflow due to dysfunctional cellular and matrix dynamics in the eye’s main drainage site, the trabecular meshwork (TM) and Schlemm’s canal (SC). The TM/SC are highly specialised tissues that regulate AqH outflow; however, their exact mechanisms of AqH outflow control are still not fully understood. Emulating physiologically relevant 3D TM/S in vitro models poses challenges to accurately mimic the complex biophysical and biochemical cues that take place in healthy and glaucomatous TM/SC in vivo. With development of such models still in its infancy, there is a clear need for more well-defined approaches that will accurately contrast the two central regions that become dysfunctional in POAG; the juxtacanalicular tissue (JCT) region of the TM and inner wall endothelia of the Schlemm’s canal (eSC). This review will discuss the unique biological and biomechanical characteristics that are thought to influence AqH outflow and POAG progression. Further consideration into fundamental biomaterial attributes for the formation of a biomimetic POAG/AqH outflow model will also be explored for future success in pre-clinical drug discovery and disease translation.

Retrospective analysis of the comparison between carbon dioxide laser-assisted deep sclerectomy combined with phacoemulsification and conventional trabeculectomy with phacoemulsification

Purpose:

To compare outcomes of laser assisted deep sclerectomy (LADS) and conventional trabeculectomy both combined with phacoemulsification.

Methods:

We divided 36 eyes into 2 groups, one group with LADS and the other Trabeculectomy. Patients were measured post operatively at 1, 3, 6, 9 months, 1, 2, 3 years for intraocular pressure (IOP), best corrected visual acuity (BCVA) and number of medications.

Results:

In the trabeculectomy group, after 3 year follow up, IOP was 14.67 ± 3.14, 15.27 ± 4.28 and 17.00 ± 7.79, BCVA improved to 0.17 ± 0.18, 0.24 ± 0.20 and 0.24 ± 0.27 and number of medications reduced to 0.6 ± 0.6, 1.1 ± 1.2, and 1.5 ± 1.5. Complete success rate after 3 years was 100%, 80.0% & 80.0% and Qualified success rate was 100%, 88.9% & 88.9%. In the LADS group, after 3 years follow up, IOP was 14.11 ± 3.91, 16.07 ± 5.51, 15.80 ± 6.07, BCVA improved to 0.13 ± 0.11, 0.10 ± 0.15, 0.11 ± 0.13 and medications reduced to 1 ± 1.1, 1.5 ± 1.0 and 1.8 ± 1.0. Complete success after 3 years was 85.7%, 57.1% & 57.1% whereas qualified success was 92.3%, 84.6% & 84.6%.

Conclusion:

Main limitations of our study were small sample size and lack of prospective comparison. However we were able to perfom the surgery comfortably due to the relatively shorter learning curve compared to conventional NPDS.

Microcatheter-Assisted Trabeculotomy Combined With Deep Sclerectomy and Trabeculectomy in Young to Middle-Aged Adults With Advanced Primary Open-Angle Glaucoma: 1-Year Result

Objective: We aimed to evaluate the safety and clinical efficacy of ab externo microcatheter-assisted trabeculotomy combined with deep sclerectomy and trabeculectomy (MATT-DS-Trab) in the surgical management of advanced primary open-angle glaucoma (POAG).

Methods: According to the inclusion criteria, we retrospectively collected and analyzed 37 POAG cases in advanced stage who received MATT-DS-Trab. The intraocular pressure (IOP), best corrected visual acuity (BCVA), use of anti-glaucoma drugs, shape of the filtering bleb, size of the scleral lake, complications, and the surgical success rate were recorded.

Results: The mean IOP was 37.50 ± 8.11 mmHg before the operation, while it depleted to 10.08 ± 2.01 and 11.43 ± 2.07 mmHg at 1 week and 12 months after the operation, respectively (both P < 0.001 compared to preoperative IOP). From none to two kinds of anti-glaucoma drugs were used 12 months after surgery on the patients, which were significantly reduced compared with that preoperatively (P < 0.001). An L-type filtering bleb was the main form at all time points after the operation. At 12 months following surgery, an F-type filtering bleb accounted for 5.41% and no E-type filtering bleb was recorded. The length and height of the scleral lake shrunk with time, but there was no statistical significance (P > 0.05). Also, there was no correlation between the size of the scleral pool and the IOP (P > 0.05). At 12 months after the operation, the complete success rates were 94.59, 83.78, and 72.97% according to standards A (≤18 mmHg), B (≤15 mmHg), and C (≤12 mmHg), respectively. Intraoperative complications were mainly anterior chamber hemorrhage, and no complications related to the filtration bleb were observed after the operation.

Conclusion: Based on multichannel mechanisms, MATT-DS-Trab is able to effectively reduce IOP in advanced POAG patients, with few serious complications and a high success rate.

Association of MTHFR C677T polymorphism with primary open angle glaucoma: a Meta-analysis based on 18 case-control studies

AIM

To systematically understand the genetic association between methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and primary open angle glaucoma (POAG).

METHODS

A comprehensive literature search in Google Scholar, PubMed, Science Citation Index, Foreign Medical Literature Retrieval Service, Chinese National Knowledge Infrastructure and Wanfang Databases was performed to collect all eligible studies up to August 2019. Study selection, data abstraction and study quality evaluation were performed by two independent investigators. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to assess the association.

RESULTS

Eighteen case-control studies including 2156 cases and 2201 controls were identified. There was no significant difference in the terms of MTHFR C677T polymorphism and POAG in the Caucasian population (for T vs C OR=1.11, 95%CI: 0.88 to 1.39; for TT vs CC OR=1.01, 95%CI: 0.76 to 1.36; for TT+TC vs CC OR=1.15, 95%CI: 0.84 to 1.58 and for TT vs TC+CC OR=1.02, 95%CI: 0.78 to 1.33). However, a significant effect was revealed in the Asian population (for T vs C OR=1.34, 95%CI: 1.12 to 1.59; for TT+TC vs CC OR=1.41, 95%CI: 1.14 to 1.76).

CONCLUSION

Based on 18 eligible studies, we provide a correlation between MTHFR C677T polymorphism and POAG among the Asians subgroup indicating that the T allele or TT +TC genotype may play a critical role in POAG development in Asians.

Types of Glaucoma and Associated Comorbidities Among Patients at King Abdulaziz Medical City, Jeddah

Aim To identify the types of glaucoma and associated comorbidities among patients attending the ophthalmology clinic at King Abdulaziz Medical City (KAMC) in Jeddah. Methods A cross-sectional study that included all glaucoma patients at KAMC in Jeddah between June 1st, 2016 and November 30th, 2020. Data were collected through retrospective chart review from the electronic medical record system (BestCare) and utilized a structured data collection sheet. Results A total of 283 patients met the inclusion criteria. The most common type was primary open-angle glaucoma (POAG; 53%) followed by secondary glaucomas (SG; 26.5%) then childhood glaucoma and primary angle-closure glaucoma (CG, PACG; 7.4%). The majority of secondary glaucoma cases were due to neovascular glaucoma (NVG; 44.9%), followed by phacomorphic glaucoma (17.9%) and phacolytic glaucoma (10.3%). Hypertension (60.8%) and diabetes (58.3%) were the most prevalent systematic comorbidities, and cataract (49.1%) was the most prevalent ocular comorbidity. Conclusion POAG was the most common glaucoma type, followed by SG, CG, and PACG. Among secondary glaucoma types, neovascular glaucoma was found to be the most common subtype. Hypertension was the most prevalent comorbid condition.

Educational intervention to adopt selective laser trabeculoplasty as first-line glaucoma treatment: Randomized controlled trial: Educational intervention on selective laser trabeculoplasty

PURPOSE

To determine the efficacy of an educational intervention on patient adoption and attitudes toward selective laser trabeculoplasty (SLT) as first-line treatment for glaucoma.

METHODS

This study is a randomized controlled trial. Subjects include 33 patients within 1-year diagnosis of either primary open-angle glaucoma, ocular hypertension, or pseudoexfoliation syndrome. After informed consent, subjects were randomly assigned to a Usual Care or Educational Intervention group. All subjects completed a pre-intervention questionnaire. The Educational Intervention group was shown a slideshow presentation and a 3-min video and given a post-intervention questionnaire. Follow-up examinations were reviewed for 6 months to determine subject completion of SLT, the primary outcome. Secondary outcomes include assessment of attitude toward SLT before and after intervention.

RESULTS

Age, gender, and baseline characteristics between the groups did not differ. The Usual Care group had a higher proportion of African Americans (77% vs 31%, p = 0.04). At 6 months following the intervention, 63% of subjects underwent SLT compared to 35% of Usual Care subjects (p = 0.12). Older age was associated with decreased SLT uptake (OR 0.90, 95% CI 0.82-0.99, p = 0.03). Prior to the intervention, there were no differences in attitudes of both groups regarding SLT therapy. Nineteen percent of Educational Intervention subjects changed positively toward SLT (p = 0.08) and 50% scheduled an SLT appointment after intervention (p = 0.005).

CONCLUSIONS

A slideshow and video-based educational intervention may positively enhance patient adoption of SLT.Clinical trial registration name, number, URL: Educational Intervention to Adopt SLT as First-Line Glaucoma Treatment, NCT03365778, https://clinicaltrials.gov/ct2/show/NCT03365778.

Comparison of structural and functional tests in primary open angle glaucoma

Purpose:

To comparatively analyze the structural and functional tests used in the diagnosis and follow-up of glaucoma.

Methods:

Eighty eyes of 40 patients with primary open angle glaucoma (POAG) and 46 eyes of 23 healthy individuals were included in the study. Transient pattern electroretinography (PERG), steady-state PERG (ssPERG), computerized visual field (VF) screening, and examination of retinal nerve fiber layer (RNFL) and macular thickness on optical coherence tomography (OCT) were undertaken. The results were compared between the groups.

Results:

80 eyes belonging to 40 patients with a diagnosis of POAG (23 female, 17 male) (18 mild 22 moderate POAG) with a mean of 57.37 (±8.6) years, and 46 eyes of 23 healthy individuals (14 female, 9 male) with a mean age of 55.30 (±8.09) years were included in the study. PERG P50 and N95 and ssPERG latency revealed a significant delay in the POAG group. When the wave amplitudes were examined, they were found to be significantly lower in both PERG and sSPERG tests for the POAG group, but the results were more pronounced in ssPERG. The latency values of PERG and ssPERG tests were not significantly correlated with any of the parameters of the remaining tests. However, the amplitude values of these tests had a positive correlation with the mean deviation value and negative correlation with the pattern standard deviation value of VF. All associated parameters were significant for the amplitude value of the ssPERG test.

Conclusion:

For the proper management of glaucoma, rather than approaching damage simply as the loss of retinal ganglion cells or the neuroretinal rim, it is necessary to focus on the ongoing anatomical and functional relationship and evaluate structural and functional tests together. In addition, ssPERG test, which is not widely adopted in routine practice, provides valuable information and is significantly correlated with OCT parameters.

Metabolomic Profiling of Aqueous Humor and Plasma in Primary Open Angle Glaucoma Patients Points Towards Novel Diagnostic and Therapeutic Strategy

Glaucoma is the second leading cause of blindness globally characterized by progressive loss of retinal ganglion cells (RGCs) and irreversible visual deficiency. As the most common type of glaucoma, primary open angle glaucoma (POAG) is currently an unmet medical need with limited therapy by lowering intraocular pressure (IOP). However, some patients continue to progress even though their IOP are controlled. Although early diagnosis and prompt treatment are crucial in preventing irreversible visual impairment, there are currently no biomarkers for screening POAG. Metabolomics has the advantages of illustrating the final downstream products of the genome and establishing the closest link to the phenotype. So far, there is no study investigating the metabolomic profiles in both aqueous humor and plasma of POAG patients. Therefore, to explore diagnostic biomarkers, unveil underlying pathophysiology and potential therapeutic strategies, a widely targeted metabolomic approach was applied using ultrahigh-resolution mass spectrometry with C18 liquid chromatography to characterize the metabolomic profiles in both aqueous humor and plasma of 28 POAG patients and 25 controls in our study. Partial least squares-discriminant analysis (PLS-DA) was performed to determine differentially expressed metabolites (DEMs) between POAG and age-matched controls. The area under the receiver operating characteristic curve (AUC) was calculated to assess the prediction accuracy of the DEMs. The correlation of DEMs with the clinical parameters was determined by Pearson correlation, and the metabolic pathways were analyzed using MetaboAnalyst 4.0. PLS-DA significantly separated POAG from controls with 22 DEMs in the aqueous humor and 11 DEMs in the plasma. Additionally, univariate ROC analysis and correlation analysis with clinical parameters revealed cyclic AMP (AUC = 0.87), 2-methylbenzoic acid (AUC = 0.75), 3'-sialyllactose (AUC = 0.73) in the aqueous humor and N-lac-phe (AUC = 0.76) in the plasma as potential biomarkers for POAG. Moreover, the metabolic profiles pointed towards the alteration in the purine metabolism pathway. In conclusion, the study identified potential and novel biomarkers for POAG by crosslinking the metabolomic profiles in aqueous humor and plasma and correlating with the clinical parameters. These findings have important clinical implications given that no biomarkers are currently available for glaucoma in the clinic, and the study provided new insights in exploring diagnostic biomarkers and potential therapeutic strategies of POAG by targeting metabolic pathways.

Ultrasound biomicroscopy in glaucoma assessment

Ultrasound biomicroscopy (UBM) is an important tool in the diagnosis, evaluation and follow up of glaucoma patients. Even if we are dealing with a primary angle closure glaucoma (PACG) or a primary open angle glaucoma (POAG) patient, the mechanism of angle closure can be revealed by performing an UBM. The device can help differentiate between the two types of glaucoma even in patients with opaque corneas when gonioscopy cannot be performed. Knowing the type of glaucoma is vital, especially regarding an individualized treatment, since each patient is unique and needs to be treated accordingly, in order to prevent glaucomatous optic neuropathy and visual field loss. Abbreviations: AC = anterior chamber, ICE = iridocorneal endothelial syndrome, IOP = intraocular pressure, NTG = normal tension glaucoma, PACG = primary angle closure glaucoma, PC = posterior chamber, PEX = pseudoexfoliation syndrome, POAG = primary open angle glaucoma, UBM = ultrasound biomicroscopy.

Comparing posture induced intraocular pressure variations in normal subjects and glaucoma patients

AIM

To compare the posture-induced variations in intraocular pressure (IOP) between the primary open angle glaucoma (POAG) and non-glaucomatous eyes.

METHODS

A case-controlled age matched study was conducted in 55 successive newly diagnosed POAG and 56 non-glaucomatous patients seen in glaucoma clinic and general outpatient eye clinic in the Alex Ekwueme University Teaching Hospital, Abakaliki. The IOPs of eligible correspondents were measured with Perkin's hand-held tonometer in the sitting, supine flat and supine with pillow positions respectively. Measurement of IOP in each position was done after 15min of assuming such posture.

RESULTS

The IOP difference between the sitting and supine flat position was significantly higher in the POAG than non-glaucoma subjects (7.68±2.08 vs 4.03±0.13 mm Hg, P<0.001). The IOP difference between the sitting and supine with pillow positions was 2.61±1.49 mm Hg for POAG and 1.44±0.70 mm Hg in non-glaucoma (P<0.001), while difference between supine flat and supine with pillow positions was 5.07±2.24 mm Hg in POAG and 2.59±0.66 mm Hg in non-glaucomatous patients (P<0.001).

CONCLUSION

Greater variations in posture induced IOP occurred in POAG patients than non-glaucomatous. The posture induced IOP variation is lowest in the sitting position and highest in the supine flat position. Evaluation of posture induced IOP changes may be an important tool in the management of glaucoma.