Prevalence of open-angle glaucoma in Greece: the Thessaloniki Eye Study

High-intensity interval training in patients with glaucoma (HIT-GLAUCOMA): protocol for a multicenter randomized controlled exercise trial

Background

Glaucoma stands as a prominent global cause of irreversible blindness and the primary treatment approach involves reducing intraocular pressure (IOP). However, around one-third of patients exhibit disease progression despite effective IOP reduction. Microvascular endothelial function, chronic inflammation, and oxidative stress are known to affect retinal neuronal networks and have been associated with disease severity and progression. Exercise training has the potential to counteract these mechanisms as add-on treatment to usual care.

Aims

The HIT-GLAUCOMA study will investigate the effects of a 6-month high-intensity interval training (HIIT) on intermediate endpoints such as local retinal microvascular and systemic large artery function, inflammation, and oxidative stress as well as clinical endpoints such as visual field indices, optic nerve rim assessment, retinal nerve fiber layer thickness, IOP, number of eye drops, vision-related quality of life and ocular surface disease symptomatology.

Methods

The study is a multi-center randomized controlled clinical trial in patients with both normal tension and high-tension primary open angle glaucoma. Across two study centers, 128 patients will be enrolled and randomized on a 1:1 basis into an exercise intervention group and a usual care control group. The primary microvascular endpoints are retinal arteriolar and venular flicker light-induced dilation at 6 months. The primary endpoint in the systemic circulation is brachial artery flow-mediated dilation at 6 months.

Anticipated results

We hypothesize that exercise therapy will improve retinal microvascular function and thus ocular blood flow in patients with glaucoma. As clinical outcomes, we will investigate the effect of exercise on visual field indices, optic nerve rim assessment, retinal nerve fiber layer thickness, IOP, number of eye drops, vision-related quality of life and ocular surface disease symptomatology.

Discussion

HIT-GLAUCOMA is a blueprint trial design to study the effect of exercise training on neurodegenerative and cardiovascular diseases. Importantly, patients are also expected to benefit from improvements in general health and cardiovascular co-morbidities. If proven effective, exercise may offer a new add-on treatment strategy to slow glaucoma progression.

Clinical Trial Registration Number

The trial is registered at Clinicaltrials.gov under the identifier NCT06058598 and is currently in the recruitment stage.

Evaluation of an offline, artificial intelligence system for referable glaucoma screening using a smartphone-based fundus camera: a prospective study

BACKGROUND/OBJECTIVES

An affordable and scalable screening model is critical for undetected glaucoma. The study evaluated the performance of an offline, smartphone-based AI system for the detection of referable glaucoma against two benchmarks: specialist diagnosis following full glaucoma workup and consensus image grading.

SUBJECTS/METHODS

This prospective study (tertiary glaucoma centre, India) included 243 subjects with varying severity of glaucoma and control group without glaucoma. Disc-centred images were captured using a validated smartphone-based fundus camera analysed by the AI system and graded by specialists. Diagnostic ability of the AI in detecting referable Glaucoma (Confirmed glaucoma) and no referable Glaucoma (Suspects and No glaucoma) when compared to a final diagnosis (comprehensive glaucoma workup) and majority grading (image grading) by Glaucoma specialists (pre-defined criteria) were evaluated.

RESULTS

The AI system demonstrated a sensitivity and specificity of 93.7% (95% CI: 87.6-96.9%) and 85.6% (95% CI:78.6-90.6%), respectively, in the detection of referable glaucoma when compared against final diagnosis following full glaucoma workup. True negative rate in definite non-glaucoma cases was 94.7% (95% CI: 87.2-97.9%). Amongst the false negatives were 4 early and 3 moderate glaucoma. When the same set of images provided to the AI was also provided to the specialists for image grading, specialists detected 60% (67/111) of true glaucoma cases versus a detection rate of 94% (104/111) by the AI.

CONCLUSION

The AI tool showed robust performance when compared against a stringent benchmark. It had modest over-referral of normal subjects despite being challenged with fundus images alone. The next step involves a population-level assessment.

Lack of Association between LOXL1 Variants and Pigment Dispersion Syndrome/Pigmentary Glaucoma: A Meta-Analysis

The phenotypic similarities between exfoliation syndrome (XFS)/exfoliation glaucoma (XFG) and pigment dispersion syndrome (PDS)/pigmentary glaucoma (PG), particularly their association with material deposition in the eye's anterior segment, have prompted investigations into genetic commonalities. This study focuses on the LOXL1 gene, conducting a comprehensive meta-analysis of three candidate gene association studies. We analyzed three single nucleotide polymorphisms (SNPs) of LOXL1: rs1048661, rs3825942, and rs2165241. Our results reveal nominal significance for the exonic SNPs rs1048661 and rs3825942 (p ≤ 0.01), but show no significant association for the intronic SNP rs2165241 (p = 0.83) with PDS/PG. There was homogeneity across study cohorts (I2 = 0), and sensitivity analyses and funnel plots confirmed a lower likelihood of bias in our findings. The lack of a statistically significant association between LOXL1 variants and PDS/PG at p < 0.05 was attributable to the insufficient statistical power of the pooled data, which ranged from 5% to 37% for the three SNPs. This study suggests no association between LOXL1 variants and PDS/PG. Further validation and exploration of XFS/XFG-associated genes in larger and more diverse cohorts would be helpful to determine the genetic correlation or distinctiveness between these conditions.

Former smoking as a risk factor for visual field progression in exfoliation glaucoma patients in Sweden

PURPOSE

The present study aimed to identify whether former smoking was a risk factor for visual field progression in exfoliation glaucoma patients.

METHODS

Prospective nonrandomised cohort study. The study included patients diagnosed with exfoliation glaucoma. All included patients were followed for three years (± three months) with reliable visual fields. At least five reliable visual fields needed to be included in the study. Exfoliation glaucoma was defined using the European Glaucoma Society Guidelines. The visual fields were tested using the 24-2 test strategy of the Humphrey Field Analyzer. Smoking was assessed through questionnaires. Outcomes: Visual field progression. Three different approaches were used: difference in mean deviation (MD), rate of progression (ROP), and guided progression analysis (GPA).

RESULTS

In total, n = 113 patients were included; among them, n = 57 were smokers. Smoking was a significant predictor for visual field progression in the three models (MD/ROP/GPA) studied (p = 0.01/p = 0.001/p ≤ 0.001), even adjusting for intraocular pressure (IOP). Other predictors were included in the MD model: IOP at diagnosis (p = 0.04) and selective laser trabeculoplasty (SLT) treatment (p = 0.01). Other predictors were in the ROP model: Visual field index (p = 0.005), number of medications (p = 0.001) and SLT treatment (p = 0.001). The number of medications was another predictor in the GPA model (p = 0.002).

CONCLUSIONS

Former smoking induced visual field deterioration in all models studied. Smoking status should be considered when establishing the glaucoma diagnosis. Increased glaucoma care should be provided to former smokers to slow the progression of the disease.

[Epidemiological and clinical features of primary open angle glaucoma in Bejaia: "The Bejaia Eye Study"]

PURPOSE

To determine the prevalence of POAG and its clinical features in a population aged 40years and over in Bejaia.

METHODS

This was a descriptive, cross-sectional survey for analytical purposes in a representative sample from the municipality of Bejaia. The target population consists of residents of the municipality aged 40 and over who were examined in basic health facilities in the municipality of Bejaia, from May 31, 2015 to July 12, 2016. The visual field, OCT, vertical C/D and intraocular pressure (IOP) criteria were used to define whether or not primary open angle glaucoma was present.

RESULTS

A total of 1484 people (99 %) participated in the study. The mean age of the study population was 57.97±10.77years, with a median of 56years and sex ratio of 1.07. The prevalence of glaucoma in our study was 5.5 %: POAG 4.6 % (95% CI=3.5-5.7); PACG 0.3 % (95 % CI=0.1, 0.7); secondary glaucoma 0.5 % (95 % CI=0.2-0.7). The prevalence of ocular hypertension was 3.0 % (95% CI=2.2-4.0). The age-adjusted prevalence was 0.8 % between 40 and 49years of age and 6.9% between 60 and 69years of age. The mean age was 66.76±9.31years for men and 67.68±12.10years for women. The mean IOP was 17.53±5.69mm Hg. The mean pachymetry was 518.3±34.3μm in the right eye and 517.4±33.9μm in the left eye. The mean cup/disc ratio was 0.7±0.2 in both eyes. Multivariate analysis of risk factors in our study showed that age and ocular hypertension were significantly associated with the presence of POAG.

DISCUSSION

The prevalence of POAG is disparate in relation to the age difference, the method of recruitment and the diagnostic criteria: in Bejaia, it is 4.6 %; in Morocco: Marrakech 2.0 %, Fez 6.4 %; in Tunisia: Bardo 2.7 %, Mahdia 2.4 %. The prevalence of POAG increases exponentially with age without significant gender difference. The inclusion of suspect cases influences the prevalence (Beaver Dam, Namil Study). We found that the prevalence of OHT in our study approximates that of the BMES, but it did not show a significant increase with age. The mean CCT in Bejaia (526.35±34.86 microns) and Fez (522.16±41.45 microns) are comparable. The mean vertical C/D ratio in Bejaia was also comparable to data in the literature. A significant difference was observed in the mean median deviation (MD) between subjects with glaucoma and normal subjects. The retinal nerve fiber layer as well as the mean ganglion cell complex thickness in glaucoma subjects was significantly thinner than in healthy subjects.

CONCLUSION

The prevalence of POAG is high, similar to that of people of African descent, but at older ages and among men. The rate of glaucoma in Bejaia rises significantly with age. Glaucoma is a major ocular health problem and will become increasingly important as the population ages.

[Use of antiglaucomatous drugs in the urban adult population : New Insights into the prevalence of glaucoma from the Hamburg City Health Study]

BACKGROUND

Glaucoma is a widespread ophthalmological disease. Knowledge about the spread of the disease in the population is necessary with respect to further questions on comorbidities, risk factors and the provision of care.

OBJECTIVE

An analysis of the use of glaucoma medications and the prevalence of glaucoma in an urban adult population was carried out.

MATERIAL AND METHODS

The Hamburg City Health Study (HCHS) is a prospective, long-term, population-based cohort study that includes a random sample of 45,000 participants aged between 45 and 79 years from the general population of Hamburg, Germany. Apart from various medical parameters, data include premedication and the medical history of the participants. The use of antiglaucomatous medication among the first 10,000 study participants was analyzed and the prevalence of glaucoma was estimated according to the use of medications as well as by the self-reported history of glaucoma. Descriptive analysis and logistic regression analysis were performed to analyze the data and to calculate correlations by age and gender.

RESULTS

In the study population 319 persons were on medication to lower the intraocular pressure (IOP, mean age 67.1 years, SD = 7.57 years), which is equivalent to an estimated prevalence of 3.35% (95% confidence interval, CI 3.00-3.70%). A positive correlation was observed between age and the use of IOP-lowering medication, which is statistically highly significant (p = < 0.001). The analysis by gender showed a slightly higher prevalence among women, which was not statistically significant. The estimated prevalence according to glaucoma medication and history were only partly congruent.

DISCUSSION

This estimated prevalence of glaucoma is comparable to other epidemiological studies. The study results cover not only patients with manifest glaucoma but also persons who were treated for ocular hypertension. The inconsistency between the prevalence of glaucoma medication and the diagnosis of glaucoma can be explained by different treatment strategies and also by information deficits.

A Systematic Review of Glaucoma Diagnosis in Prevalence Studies and Quality of Reporting

PRCIS

This systematic review has revealed that variable definitions of glaucoma continue to be used in prevalence studies, despite the introduction of the International Society of Geographic and Epidemiologic Ophthalmology (ISGEO) criteria.

PURPOSE

To systematically review diagnostic criteria and examinations performed in glaucoma prevalence studies over time and determine the quality of reporting. Accurate estimates of glaucoma prevalence are crucial to inform resource allocation. However, diagnosis of glaucoma comprises inherently subjective examinations and the cross-sectional nature of prevalence studies precludes monitoring for progression.

METHODS

A systematic review of PubMed, Embase, Web of Science, and Scopus was performed to examine diagnostic protocols used by glaucoma prevalence studies and evaluate uptake of the ISGEO criteria, introduced in 2002 to standardize glaucoma diagnosis in prevalence studies. Detection bias and compliance with the Strengthening Reporting of Observational Studies in Epidemiology (STROBE) guidelines were evaluated.

RESULTS

Ten thousand five hundred forty-four articles were identified. After deduplication, 5589 articles were screened, yielding 136 articles pertaining to 123 studies. An absence of data in many countries was identified. Ninety-two percent of studies stated diagnostic criteria, and 62% used the ISGEO criteria since their publication. Weaknesses of the ISGEO criteria were identified. Temporal variations in the performance of various examinations were observed, including heterogeneity in angle assessment. Mean STROBE compliance was 82% (range 59-100%); 72 articles had a low risk of detection bias, 4 had a high risk, and 60 had some concerns.

CONCLUSION

Heterogeneous diagnostic definitions persist in glaucoma prevalence studies, despite introduction of the ISGEO criteria. Standardization of criteria remains imperative and the development of new criteria represent a valuable opportunity to achieve this goal. In addition, methods of determining diagnoses are poorly reported, suggesting a need for improvement in study conduct and reporting. Accordingly, we propose the Reporting of quality Of GlaUcoma Epidemiological Studies (ROGUES) Checklist. We have also identified a need for further prevalence studies in regions with limited data and to update Australian angle closure glaucoma prevalence. Design and reporting of future studies can be informed by this review's insights into diagnostic protocols previously used.

A generalizable deep learning regression model for automated glaucoma screening from fundus images

A plethora of classification models for the detection of glaucoma from fundus images have been proposed in recent years. Often trained with data from a single glaucoma clinic, they report impressive performance on internal test sets, but tend to struggle in generalizing to external sets. This performance drop can be attributed to data shifts in glaucoma prevalence, fundus camera, and the definition of glaucoma ground truth. In this study, we confirm that a previously described regression network for glaucoma referral (G-RISK) obtains excellent results in a variety of challenging settings. Thirteen different data sources of labeled fundus images were utilized. The data sources include two large population cohorts (Australian Blue Mountains Eye Study, BMES and German Gutenberg Health Study, GHS) and 11 publicly available datasets (AIROGS, ORIGA, REFUGE1, LAG, ODIR, REFUGE2, GAMMA, RIM-ONEr3, RIM-ONE DL, ACRIMA, PAPILA). To minimize data shifts in input data, a standardized image processing strategy was developed to obtain 30° disc-centered images from the original data. A total of 149,455 images were included for model testing. Area under the receiver operating characteristic curve (AUC) for BMES and GHS population cohorts were at 0.976 [95% CI: 0.967-0.986] and 0.984 [95% CI: 0.980-0.991] on participant level, respectively. At a fixed specificity of 95%, sensitivities were at 87.3% and 90.3%, respectively, surpassing the minimum criteria of 85% sensitivity recommended by Prevent Blindness America. AUC values on the eleven publicly available data sets ranged from 0.854 to 0.988. These results confirm the excellent generalizability of a glaucoma risk regression model trained with homogeneous data from a single tertiary referral center. Further validation using prospective cohort studies is warranted.

The Role of Oxidative Status in the Pathogenesis of Primary Open-Angle Glaucoma, Pseudoexfolyation Syndrome and Glaucoma

PURPOSE

To investigate the role of oxidative stress and antioxidant system in the etiopathogenesis of pseudoexfoliation and progression of pseudoexfoliation syndrome to glaucoma.

MATERIAL AND METHOD

A total of 20 patients with pseudoexfoliation syndrome, 20 with pseudoexfoliation glaucoma, 20 with primary open-angle glaucoma, and 20 without pseudoexfoliation and glaucoma as a control group, who underwent cataract or glaucoma surgery between December 2020 and March 2021 in the Health Sciences University Beyoğlu Eye Training and Research Hospital, 80 patients were included in the study. Best corrected visual acuity (BCVA), intraocular pressure with applanation tonometry, detailed anterior and posterior segment examinations with biomicroscopy were performed in all patients included in the study. Approximately 0.1 cc of anterior chamber fluid was taken from all patients at the beginning of surgery. Total Oxidant Status (TOS) and Total Antioxidant Status (TAS) levels were measured by keeping the samples taken in the deep freezer of the cornea bank at -80 degrees, transferring them with cold chain transport rules, and examining them with automatic measurement method in the laboratories of the Medical Biochemistry Department of the University of Health Sciences. Oxidative Stress Index (OSI) value was calculated to measure the degree of oxidative stress.

RESULTS

TAS averages of the control and POAG groups were found to be statistically significantly higher than the PES and PEG groups (p = 0.0001, p = 0.0001). No significant difference was observed between the other groups (p > 0.05). The TOS averages of the control and POAG groups were found to be statistically significantly lower than the PES and PEG groups (p = 0.003, p = 0.0001; p = 0.01, p = 0.001), no statistically significant difference was observed between the other groups (p > 0.05). The OSI mean of the control and POAG groups was found to be statistically significantly lower than the PES and PEG groups (p = 0.001, p = 0.0001; p = 0.002, p = 0.0001), no statistically significant difference was observed between the other groups (p > 0.05).

CONCLUSION

Increased TOS and OSI and decreased TAS levels in the aqueous humour of patients with PES and PEG suggest that increased oxidative stress and decreased antioxidative defense system play a role in the etiopathogenesis of the disease.

Using deep leaning models to detect ophthalmic diseases: A comparative study

Purpose

The aim of this study was to prospectively quantify the level of agreement among the deep learning system, non-physician graders, and general ophthalmologists with different levels of clinical experience in detecting referable diabetic retinopathy, age-related macular degeneration, and glaucomatous optic neuropathy.

Methods

Deep learning systems for diabetic retinopathy, age-related macular degeneration, and glaucomatous optic neuropathy classification, with accuracy proven through internal and external validation, were established using 210,473 fundus photographs. Five trained non-physician graders and 47 general ophthalmologists from China were chosen randomly and included in the analysis. A test set of 300 fundus photographs were randomly identified from an independent dataset of 42,388 gradable images. The grading outcomes of five retinal and five glaucoma specialists were used as the reference standard that was considered achieved when ≥50% of gradings were consistent among the included specialists. The area under receiver operator characteristic curve of different groups in relation to the reference standard was used to compare agreement for referable diabetic retinopathy, age-related macular degeneration, and glaucomatous optic neuropathy.

Results

The test set included 45 images (15.0%) with referable diabetic retinopathy, 46 (15.3%) with age-related macular degeneration, 46 (15.3%) with glaucomatous optic neuropathy, and 163 (55.4%) without these diseases. The area under receiver operator characteristic curve for non-physician graders, ophthalmologists with 3-5 years of clinical practice, ophthalmologists with 5-10 years of clinical practice, ophthalmologists with >10 years of clinical practice, and the deep learning system for referable diabetic retinopathy were 0.984, 0.964, 0.965, 0.954, and 0.990 (p = 0.415), respectively. The results for referable age-related macular degeneration were 0.912, 0.933, 0.946, 0.958, and 0.945, respectively, (p = 0.145), and 0.675, 0.862, 0.894, 0.976, and 0.994 for referable glaucomatous optic neuropathy, respectively (p < 0.001).

Conclusion

The findings of this study suggest that the accuracy of this deep learning system is comparable to that of trained non-physician graders and general ophthalmologists for referable diabetic retinopathy and age-related macular degeneration, but the deep learning system performance is better than that of trained non-physician graders for the detection of referable glaucomatous optic neuropathy.

Artificial Intelligence to Aid Glaucoma Diagnosis and Monitoring: State of the Art and New Directions

Recent developments in the use of artificial intelligence in the diagnosis and monitoring of glaucoma are discussed. To set the context and fix terminology, a brief historic overview of artificial intelligence is provided, along with some fundamentals of statistical modeling. Next, recent applications of artificial intelligence techniques in glaucoma diagnosis and the monitoring of glaucoma progression are reviewed, including the classification of visual field images and the detection of glaucomatous change in retinal nerve fiber layer thickness. Current challenges in the direct application of artificial intelligence to further our understating of this disease are also outlined. The article also discusses how the combined use of mathematical modeling and artificial intelligence may help to address these challenges, along with stronger communication between data scientists and clinicians.

Clinical outcomes following selective laser trabeculoplasty in Afro-Caribbean patients with glaucoma at high risk for progression

AIM

To characterise clinical outcomes following selective laser trabeculoplasty (SLT) in eyes of Afro-Caribbean patients with open-angle glaucoma (OAG) at high risk for progression.

METHODS

In a prospective interventional case series, patients meeting high-risk criteria (advanced disease, unilateral glaucoma blindness, inadequate intraocular pressure (IOP) on >2 medications, recent progression on medications, inability to administer, afford or tolerate medications) underwent bilateral 360° SLT and managed based on their subsequent clinical course. Patient-specific indications for SLT-IOP reduction (IOP group) or reduced reliance on medical therapy (MED group)-were recorded before treatment. IOP and medication use were recorded every 3-4 months through up to 24 months of follow-up. Outcomes were analysed separately in the IOP and MED groups.

RESULTS

Among 33 right eyes (left eye outcomes were similar) in the IOP group, mean (SD) IOP was significantly reduced from 21.7 (7.5) mm Hg to 16.2-17.1 mm Hg over follow-up (p<0.0177); medication use remained unchanged (p>0.05) at all time points. Among 36 right eyes in the MED group, mean medication use was 1.9 (0.9) at baseline and ranged from 1.2 to 1.4 medications per eye through follow-up (p<0.0033), and mean IOP was significantly reduced at months 1-6 (to 13.1 (2.3) mm Hg, p=0.0013), months 13-18 (to 14.3 (2.8), p=0.0136) and unchanged at other time points. No vision-threatening adverse events occurred.

CONCLUSIONS

Afro-Caribbean patients with OAG at risk for progression can achieve clinically and statistically significant reductions in IOP or medications through up to 24 months following a single 360° SLT treatment.

TRIAL REGISTRATION NUMBER

NCT02375009.

Primary Open-angle Glaucoma Prevalence in EUROPE: A Systematic Review and Meta-analysis

PRCIS

Primary open-angle glaucoma is a neurodegenerative disease highly prevalent in the European adult population, with cases expected to increase over the next 30 years.

PURPOSE

This study aimed to evaluate the prevalence of primary open-angle glaucoma (POAG) in Europe.

METHODS

Two authors independently conducted a systematic literature search on PubMed/MedLine, Web of Science, and Google Scholar to identify papers analysing the prevalence of POAG in European countries. After removal of duplicates, title and abstract screening, and full-text analysis, data from selected articles were entered in an Excel spreadsheet. We performed risk of bias assessment using the Joanna Briggs Institute Prevalence Critical Appraisal Tool and conducted a meta-analysis using the R software (version 1.4.1106).

RESULTS

We retrieved 9,348 eligible papers from the initial electronic search and included 10 of them in the qualitative and quantitative analyses. A total of 26,993 patients were included in this meta-analysis (11,927 male and 14,556 female). We identified 755 POAG cases (397 male and 348 female), with a pooled prevalence estimate in Europe of 2.60% (95% confidence interval: 1.90-3.56%). Increasing odds for POAG were related to increasing age and some geographic differences in the disease distribution in the continent were identified. Statistically significant sex-related differences in the prevalence rate of POAG were not observed in this cohort.

CONCLUSION

POAG is a neurodegenerative disease that affects a large proportion of the older European population. In the future, the prevalence of POAG is expected to grow in Europe because of the progressive ageing populations of Western countries. Future high-quality epidemiological studies for the evaluation of POAG prevalence rate are warranted.

Association Between Dietary Salt Intake and Open Angle Glaucoma in the Thessaloniki Eye Study

PRCIS

In the Thessaloniki Eye Study (TES) incidence phase population, frequent dietary salt intake was potentially associated with increased risk of open angle glaucoma in antihypertensive users.

PURPOSE

The aim was to examine the association between dietary salt intake and glaucoma by antihypertensive use in the TES population.

MATERIALS AND METHODS

The study population included TES incidence phase participants. Dietary salt intake frequency was assessed by self-report. Outcomes included prevalence of any open angle glaucoma (OAG), primary open angle glaucoma (POAG), and pseudoexfoliation (PEX). Covariates included demographics, cardiovascular disease, migraines, diabetes, steroid use, smoking, history of cataract surgery, central corneal thickness, intraocular pressure, blood pressure, and antihypertensive use. Logistic regression was used to examine associations between frequency of salt intake and glaucoma, controlling for covariates and stratified by antihypertensive use.

RESULTS

The study included 1076 participants 80.5±4.4 years old, of whom 518 were female. There were 89/1076 (8.3%) participants with any OAG, 46/789 (5.8%) with POAG, and 287/1030 (27.9%) with PEX. In participants with antihypertensive use, frequent versus never salt intake was associated with increased risk of any OAG [adjusted odds ratio (aOR)=2.65, 95% confidence interval (CI)=1.12, 6.28; n=784] and POAG (aOR=3.59, 95% CI=1.16, 11.11; n=578) overall, and additionally in participants with diastolic blood pressure <90 mm Hg (aOR=2.42, 95% CI=1.00, 5.84; n=735) for OAG. There were no statistically significant adjusted associations between salt intake and PEX, or in participants without antihypertensive use.

CONCLUSIONS

In TES participants assessed for OAG in the prevalence and incidence phases, frequent salt intake may be associated with increased OAG in those who take antihypertensive medication. Further investigation is needed of salt intake and glaucoma in hypertensive individuals.

Investigation of the Role of Convolutional Neural Network Architectures in the Diagnosis of Glaucoma using Color Fundus Photography

Objectives:

To evaluate the performance of convolutional neural network (CNN) architectures to distinguish eyes with glaucoma from normal eyes.

Materials and Methods:

A total of 9,950 fundus photographs of 5,388 patients from the database of Eskişehir Osmangazi University Faculty of Medicine Ophthalmology Clinic were labelled as glaucoma, glaucoma suspect, or normal by three different experienced ophthalmologists. The categorized fundus photographs were evaluated using a state-of-the-art two-dimensional CNN and compared with deep residual networks (ResNet) and very deep neural networks (VGG). The accuracy, sensitivity, and specificity of glaucoma detection with the different algorithms were evaluated using a dataset of 238 normal and 320 glaucomatous fundus photographs. For the detection of suspected glaucoma, ResNet-101 architectures were tested with a data set of 170 normal, 170 glaucoma, and 167 glaucoma-suspect fundus photographs.

Results:

Accuracy, sensitivity, and specificity in detecting glaucoma were 96.2%, 99.5%, and 93.7% with ResNet-50; 97.4%, 97.8%, and 97.1% with ResNet-101; 98.9%, 100%, and 98.1% with VGG-19, and 99.4%, 100%, and 99% with the 2D CNN, respectively. Accuracy, sensitivity, and specificity values in distinguishing glaucoma suspects from normal eyes were 62%, 68%, and 56% and those for differentiating glaucoma from suspected glaucoma were 92%, 81%, and 97%, respectively. While 55 photographs could be evaluated in 2 seconds with CNN, a clinician spent an average of 24.2 seconds to evaluate a single photograph.

Conclusion:

An appropriately designed and trained CNN was able to distinguish glaucoma with high accuracy even with a small number of fundus photographs.

Opportunistic Eye Screening Among First-Degree Relatives of Glaucoma Patients at a Suburban Tertiary Center in Malaysia

Background and objective

The majority of glaucoma patients are asymptomatic and are usually diagnosed at an advanced stage of the disease. This study aimed to assess the outcomes of glaucoma screening among known first-degree relatives of primary glaucoma patients.

Materials and methods

This study involved primary angle-closure glaucoma (PACG), primary open-angle glaucoma (POAG), and juvenile open-angle glaucoma (JOAG) patients who attended the glaucoma clinic at the Hospital Universiti Sains Malaysia between January 2014 and December 2015. First-degree relatives of the patients underwent a preliminary eye-screening evaluation, including visual acuity (Snellen chart), intraocular pressure (IOP) measurement (air-puff tonometry), and non-mydriatic fundus photography. Patients with visual acuity worse than 6/12, IOP measuring more than 21 mmHg or a difference of more than 3 mmHg between the eyes, and a vertical cup-disc ratio (VCDR) of 0.7 or higher were given a comprehensive eye examination.

Results

Seventy indexed glaucoma patients were recognized, and 368 first-degree relatives were identified. Forty-five relatives underwent the preliminary screening. Of these, 29 showed normal findings (62%), one had corneal pathology (2%), and 16 (36%) underwent a complete eye examination after failing the initial screening. Among the indexed JOAG group, five relatives (11%) were diagnosed as having JOAG; two were treated medically, while the remaining three required surgical intervention.

Conclusion

Opportunistic glaucoma screening of high-risk groups, especially JOAG is a feasible and cost-effective way to detect early glaucoma and prevent irreversible blindness. However, improvement in our healthcare system, including the involvement of multicentre clinics in other states in screening initiatives, is required to promote and facilitate the response to screening opportunities.

The genetic basis for adult onset glaucoma: Recent advances and future directions

Glaucoma, a diverse group of eye disorders that results in the degeneration of retinal ganglion cells, is the world's leading cause of irreversible blindness. Apart from age and ancestry, the major risk factor for glaucoma is increased intraocular pressure (IOP). In primary open-angle glaucoma (POAG), the anterior chamber angle is open but there is resistance to aqueous outflow. In primary angle-closure glaucoma (PACG), crowding of the anterior chamber angle due to anatomical alterations impede aqueous drainage through the angle. In exfoliation syndrome and exfoliation glaucoma, deposition of white flaky material throughout the anterior chamber directly interfere with aqueous outflow. Observational studies have established that there is a strong hereditable component for glaucoma onset and progression. Indeed, a succession of genome wide association studies (GWAS) that were centered upon single nucleotide polymorphisms (SNP) have yielded more than a hundred genetic markers associated with glaucoma risk. However, a shortcoming of GWAS studies is the difficulty in identifying the actual effector genes responsible for disease pathogenesis. Building on the foundation laid by GWAS studies, research groups have recently begun to perform whole exome-sequencing to evaluate the contribution of protein-changing, coding sequence genetic variants to glaucoma risk. The adoption of this technology in both large population-based studies as well as family studies are revealing the presence of novel, protein-changing genetic variants that could enrich our understanding of the pathogenesis of glaucoma. This review will cover recent advances in the genetics of primary open-angle glaucoma, primary angle-closure glaucoma and exfoliation glaucoma, which collectively make up the vast majority of all glaucoma cases in the world today. We will discuss how recent advances in research methodology have uncovered new risk genes, and how follow up biological investigations could be undertaken in order to define how the risk encoded by a genetic sequence variant comes into play in patients. We will also hypothesise how data arising from characterising these genetic variants could be utilized to predict glaucoma risk and the manner in which new therapeutic strategies might be informed.

Influence of implantation of diffractive trifocal intraocular lenses on standard automated perimetry

Background

This prospective comparative study aimed to investigate the influence of diffractive trifocal intraocular lenses (IOLs) implantation on standard automated perimetry.

Methods

Patients with no diseases affecting the visual field had undergone cataract surgery following the implantation of trifocal or monofocal IOLs from July 2019 to August 2020 were recruited. The normality of the anterior and posterior segments and absence of glaucomatous optic nerve cupping were confirmed preoperatively by slit-lamp examination. Standard automated perimetry was performed using Humphrey Visual Field 10–2 testing, 2–3 months after cataract surgery in only one eye per patient. The mean deviation (MD) and foveal sensitivity were compared between IOLs in eyes with acceptable reliability indices and best-corrected visual acuity of 20/25 or better.

Results

Among the 83 eyes of the 83 patients included, 39 and 29 eyes eligible for perimetry analysis had trifocal and monofocal IOLs, respectively. The mean MD and foveal sensitivity in eyes with trifocal IOLs were significantly lower than those in eyes with monofocal IOLs (P < 0.021), with mean differences of 0.77 and 1.01 dB, respectively.

Conclusion

The comparison in nonglaucomatous eyes demonstrated that the influence of trifocal IOLs on standard automated perimetry was greater than that of monofocal IOLs.

Glaucoma Suspects: The Impact of Risk Factor-Driven Review Periods on Clinical Load, Diagnoses, and Healthcare Costs

Purpose

To model the healthcare impact (clinical attendance time and financial cost) and clinical outcomes (glaucoma diagnoses) of different risk factor–driven review frequencies for glaucoma suspect patients up until the point of discharge or diagnosis.

Methods

Medical records of 494 glaucoma suspects were examined to extract the clinical diagnosis. Two criteria for review periods were defined, based on contrasting stringency from established clinical guidelines: American Academy of Ophthalmology (AAO), more stringent/less frequent; and the Australian National Health and Medical Research Council (NHMRC), less stringent/more frequent. We used these data to model patient outcomes and healthcare costs using a Markov model.

Results

The less stringent/more frequent criterion resulted in more high-risk glaucoma suspects requiring more frequent review compared with the more stringent/less frequent criterion. Across the 15 Markov cycles (7.5 years), the less stringent/more frequent review criterion resulted in 6.6% more diagnoses and fewer overall clinical visits (14.7%) and reduced cost per diagnosis by 12% to 32% (P < 0.0001). The number of glaucoma diagnoses made using each criterion converged at 2.5 to 3 years.

Conclusions

The stringency of risk assessments for glaucoma suspects impacts review periods and therefore clinical load, healthcare costs, and diagnosis rates. Using current testing methods, more frequent review periods appear advantageous for diagnostic efficiency, with both lower clinic load and lower cost up until the point of discharge or glaucoma diagnosis.

Translational Relevance

A less stringent criterion for assessing the risk of developing glaucoma potentially offers a more cost-effective method for reviewing glaucoma suspects, especially within the first 2.5 years.

Distribution of intraocular pressure in a Swedish population

BACKGROUND

Increased intraocular pressure (IOP) and pseudoexfoliation (PEX) are major risk factors for open-angle glaucoma (OAG), an age-related neurodegenerative disease of significant importance for public health. There are few studies on the distribution of IOP in populations where PEX is a common finding.

METHODS

The distribution of IOP was studied in 733 subjects 65-74 years of age, examined in a population survey in the rural district of Tierp, Sweden, 1984-86. The difference between the right and left eye and the effect of which eye was measured first were examined. Odds ratios, adjusted for age and sex, according to Mantel-Haenszel (OR_MH), were calculated to estimate predictors of increased IOP, defined as a pressure ≥20 mm Hg in either eye. The pressure was measured with Goldmann applanation tonometry. Automated perimetry was used to identify OAG.

RESULTS

The distribution of IOP was close to that of other European-derived populations. The pressure in the first measured eye was higher than in the second measured eye. Increased IOP was related to OAG and PEX, OR_MH 8.97 (95% confidence interval [CI] 3.84-20.9) and 2.40 (95% CI 1.53-3.76), respectively. An IOP ≥20 mm Hg increased the risk of having been diagnosed with diabetes (OR_MH 1.83; 95% CI 1.08-3.09).

CONCLUSION

In this study of subjects 65-74-years-old in Sweden, the distribution of IOP was close to that of other European-derived populations. Although the difference was small, the pressure in the first measured eye was higher than in the second eye. Increased IOP was strongly related to untreated OAG and PEX.

Twelve-Year Incidence of Open-angle Glaucoma: The Thessaloniki Eye Study

OBJECTIVE

The objective of this study was to determine the 12-year incidence of open-angle glaucoma (OAG), with further classification into primary open-angle glaucoma (POAG) and pseudoexfoliative glaucoma (PEXG), in an elderly White population.

DESIGN

A longitudinal, population-based study in urban Northern Greece.

PARTICIPANT

Surviving cohort of the 2554 Thessaloniki Eye Study subjects 60 years and above who had the baseline examination.

METHODS

The surviving cohort was re-examined 12 years after baseline, using the same methodology and the same standard operating procedures as in the baseline examination. The definitions of glaucoma and pseudoexfoliation were consistent throughout the study. The 12-year incidences of OAG, POAG, and PEXG with corresponding 95% confidence intervals (CIs) were calculated for the whole study population, consisting of clinic-visit and home-visit participants. The population at risk was defined as those who did not meet the study criteria for the diagnosis of glaucoma in either eye at baseline.

MAIN OUTCOME MEASURES

Twelve-year incidence of OAG, with further classification into POAG and PEXG.

RESULTS

Of 1468 eligible subjects in the surviving cohort, 1092 were examined (participation rate 74%). Mean age at baseline was 68.9±4.6 years. Mean follow-up time was 11.6±1.6 years. The 12-year incidence of OAG was 4.4% (95% CI: 3.3-5.8); 0.37% per year. In the overall population the incidence of POAG and PEXG was 2.1% (95% CI: 1.3-3.2) and 2.3% (95% CI: 1.5-3.4), respectively. The corresponding incidence proportions were 2.9 (95% CI: 1.8-4.3) in those without PEX and 8.9 (95% CI: 5.8-12.9) in those with PEX at baseline and/or incidence. The latter was strongly associated with higher odds for incident glaucoma (odds ratio=3.34, 95% CI: 1.83-6.08, P<0.001). Of all incident OAG cases, 11.1% (95% CI: 4.4-24) had baseline intraocular pressure >21 mm Hg.

CONCLUSIONS

The incidence of OAG was similar or higher compared with other White populations. The incidence of glaucoma in those with PEX was higher compared with the incidence of glaucoma in those without PEX.

Prevalence of primary open angle glaucoma in the last 20 years: a meta-analysis and systematic review

Primary open-angle glaucoma (POAG) is a leading cause of irreversible blindness in the world and is influenced by various sociodemographic factors. This meta-analysis aims to determine the worldwide prevalence of POAG in the adult general population for the last 20 years, and explore variation in prevalence by age, gender and geographical location. An electronic literature search was performed using the PubMed, Embase, and Web of Science databases. Population-based cross-sectional or cohort studies published in the last 20 years (2000–2020) that reported prevalence of POAG were recruited. Relevant studies meeting defined eligibility criteria were selected and reviewed systematically by meta-analysis. The prevalence of POAG was analyzed according to various risk factors. A random effect model was used for the meta-analysis. Fifty publications with a total of 198,259 subjects were included in this meta-analysis. The worldwide overall prevalence of POAG was 2.4% (95% CI 2.0 ~ 2.8%). The prevalence increases with age. Men are found to be more susceptible to POAG than women (RR 1.28, p < 0.01). Africa is found to have the highest prevalence of POAG (4.0%) among all continents. The current estimated global population of POAG is 68.56 million (95% CI 59.99 ~ 79.98). POAG is a worldwide vision threatening disease with high prevalence for the last 20 years. The population-based prevalence of POAG varies widely across individual studies, due to variations in risk factors of age, gender, and population geographic location.

Agreement of findings of glaucoma screening between trained vision center technicians and glaucoma specialists at a tertiary hospital in South India

Purpose:

To study the agreement of findings of glaucoma screening between trained vision center (VC) technicians and glaucoma specialists in patients referred from VC to the glaucoma services of a tertiary eye care hospital in south India.

Methods:

This was a retrospective study comparing the findings of the VC technicians and the specialists of the glaucoma services in the base hospital, in patients referred from 13 VCs between January and June 2019. Medical records of 277 referred patients (out of 533 referrals) who attended the glaucoma clinic were analyzed.

Results:

Of the 277 patients, 111 (40%) were confirmed having glaucoma, 133 (48%) were suspects, 29 (10.4%) were normal, and four (1.4%) had other pathology. The mean age of the patients was 59.7 ± 13 years and 60.6% were females. There was no statistically significant difference between the mean intraocular pressure (IOP) measured (17 ± 7.2 mmHg at the VC and 18 ± 8.7 mmHg at the clinic, p = 0.16) and the cup-to-disc ratio (CDR) (0.7 ± 0.13 at the VC and 0.6 ± 0.18 at the clinic, p = 0.57). Bland–Altman plots with 95% limits of agreement supported that mean differences were close to zero, and the intraclass correlation coefficient at 95% CI showed good consistency between the measurement of IOP (0.78 [0.74 to 0.81]) and CDR (0.90 [0.88 to 0.92]) at the base hospital and vision center.

Conclusion:

There is good agreement between the findings of VC technicians and glaucoma specialists. VC technicians can help in detecting glaucoma in the community.

Agreement of Optic Nerve Head Evaluation of Primary Open-Angle Glaucoma Between General Ophthalmologists and Glaucoma Specialists

Purpose

To investigate the agreement of optic nerve head evaluations and initial diagnoses of primary open-angle glaucoma (POAG) by general ophthalmologists and glaucoma specialists in Shanghai, China.

Methods

This multicenter, cross-sectional study involved the outpatients from the general ophthalmology departments of four top eye hospitals in Shanghai. The participants underwent ocular examinations, including intraocular pressure, fundus photography, corneal thickness, refractometry, visual acuity, visual field and gonioscopy. General ophthalmologists and glaucoma specialists performed the diagnoses and classified them as non-glaucoma, POAG suspects, and POAG. The consistency of initial diagnosis between general ophthalmologists and glaucoma specialists was measured using the weighted kappa coefficient. Logistic regression analysis was used to detect the risk factors for the reliability of POAG diagnosis.

Results

In 922 participants, the initial diagnosis rates of POAG and non-glaucoma were much higher in the glaucoma specialist group than in the general ophthalmologist group, while the initial diagnosis rates of POAG suspects were higher in the general ophthalmologist group. The weighted kappa coefficient between the two groups was 0.831±0.027 (95% confidence interval, 0.779–0.884). Logistic regression analysis of the risk factors for the reliability of POAG diagnosis showed that the independent risk factors were intraocular pressure (OR 8.363, 95% CI: 4.27–16.37) and vertical cup-to-disc ratio (OR 3.459, 95% CI: 1.54–7.76).

Conclusion

The diagnosis consistency between the general ophthalmologists and the glaucoma specialists was similar among outpatients in the area of Shanghai. However, general ophthalmologists tended to classify the indefinite subjects as POAG suspects, and their accuracy in diagnosing POAG was low. By paying more attention to the risk factors of POAG diagnosis, general ophthalmologists could improve the diagnosis accuracy.

Molecular Genetics of Glaucoma: Subtype and Ethnicity Considerations

Glaucoma, the world’s leading cause of irreversible blindness, is a complex disease, with differential presentation as well as ethnic and geographic disparities. The multifactorial nature of glaucoma complicates the study of genetics and genetic involvement in the disease process. This review synthesizes the current literature on glaucoma and genetics, as stratified by glaucoma subtype and ethnicity. Primary open-angle glaucoma (POAG) is the most common cause of glaucoma worldwide, with the only treatable risk factor (RF) being the reduction of intraocular pressure (IOP). Genes associated with elevated IOP or POAG risk include: ABCA1, AFAP1, ARHGEF12, ATXN2, CAV1, CDKN2B-AS1, FOXC1, GAS7, GMDS, SIX1/SIX6, TMCO1, and TXNRD2. However, there are variations in RF and genetic factors based on ethnic and geographic differences; it is clear that unified molecular pathways accounting for POAG pathogenesis remain uncertain, although inflammation and senescence likely play an important role. There are similar ethnic and geographic complexities in primary angle closure glaucoma (PACG), but several genes have been associated with this disorder, including MMP9, HGF, HSP70, MFRP, and eNOS. In exfoliation glaucoma (XFG), genes implicated include LOXL1, CACNA1A, POMP, TMEM136, AGPAT1, RBMS3, and SEMA6A. Despite tremendous progress, major gaps remain in resolving the genetic architecture for the various glaucoma subtypes across ancestries. Large scale carefully designed studies are required to advance understanding of genetic loci as RF in glaucoma pathophysiology and to improve diagnosis and treatment options.

The prevalence and incidence of glaucoma in Norway 2004-2018: A nationwide population-based study

PURPOSE

To describe prevalence, life-time prevalence and incidence of glaucoma in Norway over a 15-year period.

MATERIALS AND METHODS

Data from The Norwegian Prescription Database was used to identify all prescriptions for glaucoma medication during the period 2004 to 2018. Population figures and lifespan data were obtained from The National Bureau of Statistics.

RESULTS

Of a population of 5.3 million, a total of 75733 patients using glaucoma eye drops were identified in 2018. The national prevalence was thus 1.4%, whilst in those over 70 years of age, 8.0%. When divided into counties, the prevalence varied between 1.1 and 1.9%. Overall, the prevalence was stable in the period 2004-2018. Life time prevalence was found to be 9.4% for men and 10.2% for women. National one-year incidence proportion per 10000 was 17.0 for the total population and a peak incidence of 93.8/10000 in the 80-89 year age group was identified.

CONCLUSIONS

Glaucoma prevalence remained stable during the period 2004-2018, while incidence decreased slightly in the elderly population.

Cohort Study of Nonmelanoma Skin Cancer and the Risk of Exfoliation Glaucoma

PRECIS

In a cohort study of 120,307 participants with 25+ years of follow-up, a history of nonmelanoma skin cancer (NMSC) was associated with a 40% higher exfoliation glaucoma (XFG) risk.

PURPOSE

The purpose of this study was to evaluate the relationship between NMSC (a marker of ultraviolet radiation exposure) and XFG.

METHODS

We performed a cohort study of US women (n=79,102; 1980-2014) and men (n=41,205; 1986-2014), aged 40+ years and at risk for glaucoma who reported eye examinations. From 1984 (women)/1988 (men), we asked about basal cell carcinoma or squamous cell carcinoma history separately; in prior years, we asked about any NMSC history in a single question. Squamous cell carcinoma was confirmed with histopathology reports while basal cell carcinoma and any early (<1984/<1988) NMSC history was self-reported. Incident XFG cases (362 women and 83 men) were confirmed with medical records. Using pooled data, we estimated multivariable-adjusted relative risks [MVRRs; 95% confidence intervals (CIs)] with Cox proportional hazards models that were stratified by age (in mo), 2-year time period at risk and average lifetime residential latitude.

RESULTS

In multivariable-adjusted analyses, we observed a 40% higher XFG risk with any NMSC history (MVRR=1.40; 95% CI=1.08-1.82); the association was observed even with 4 and 8-year lags in NMSC history. Also, the NMSC association was stronger in younger (below 65 y; MVRR=2.56; 95% CI=1.62-4.05) versus older participants (65 y and above; MVRR=1.25; 95% CI=0.94-1.66; P for interaction=0.01) and those living in the northern latitudes (≥42°N; MVRR=1.92; 95% CI=1.28-2.88) versus more southern latitudes (<42°N; MVRR=1.19; 95% CI=0.86-1.66; P for interaction=0.04).

CONCLUSION

NMSC was associated with higher XFG risk, particularly among younger participants and those living in the Northern US.

Prevalence and associated factors of glaucoma in the Russian Ural Eye and Medical Study

To assess the prevalence and associated factors of glaucoma in a Russian population. The population-based Ural Eye and Medical Study included 5899 (mean age 59.0 ± 10.7 years; range 40–94 years). Glaucomatous optic neuropathy was diagnosed using International Society of Geographical and Epidemiological Ophthalmology (ISGEO) criteria. Among 5545 participants with assessable optic disc photographs, 246 individuals [4.4%; 95% confidence interval (CI) 3.9, 5.0] had glaucoma, with open-angle glaucoma (OAG) in 177 individuals (3.2%; 95% CI 2.7, 3.7) and angle-closure glaucoma (ACG) in 69 individuals (1.2; 95% CI 1.0, 1.5), with IOP > 21 mmHg in 79 (32.1%) patients, and with 80 (32.5%) patients on glaucoma therapy. Glaucoma prevalence increased from 3/485 (0.6%; 95% CI 0.0, 1.3) in the age group of 40–45 years to 33/165 (20.0%; 95% CI 13.8, 26.2) in the group aged 80 + years. Higher OAG prevalence correlated with older age [odds ratio (OR) 1.07; 95% CI 1.04, 1.09; P < 0.001], longer axial length (OR 1.36; 95% CI 1.17, 1.58; P < 0.001), higher intraocular pressure (IOP) (OR 1.18; 95% CI 1.13, 1.23; P < 0.001), higher stage of lens pseudoexfoliation (OR 1.26; 95% CI 1.08, 1.47; P = 0.004) and lower diastolic blood pressure (OR 0.98; 95% CI 0.96, 0.99; P = 0.035). Higher ACG prevalence correlated with older age (OR 1.07; 95% CI 1.03, 1.11; P < 0.001), narrower anterior chamber angle (OR 0.81; 95% CI 0.77, 0.86; P < 0.001), and higher IOP (OR 1.30; 95% CI 1.23, 1.38; P < 0.001). Glaucoma caused moderate to severe vision impairment (MSVI) in 9 (4.9%; 95% CI 1.8, 8.1) out of 184 individuals with MSVI (OAG, n = 7; ACG, n = 2), and blindness in one (9.1%) of 11 blind individuals. In this population from Russia, two thirds of glaucoma patients were not on therapy, and in two thirds of the glaucoma patients IOP was ≤ 21 mmHg. Otherwise, glaucoma prevalence, OAG-to-ACG ratio, and glaucoma associations did not differ markedly from Caucasian and East Asian populations.

Pseudoexfoliation syndrome and relating factors in a rural Japanese population: the Kumejima Study

PURPOSE

To report the prevalence of pseudoexfoliation (PEX) syndrome and glaucoma associated with PEX (PEX-G) and their relating factors of them in a south-western island of Japan.

METHODS

A population-based survey of all residents aged ≥ 40 years was conducted in Kumejima, Okinawa, Japan, and 3762 subjects (participation rate, 81.2%) underwent detailed ophthalmic examinations. Presence of PEX material on the lens capsule, iris surface and/or pupillary margin was determined by slit-lamp biomicroscopy. Glaucoma was diagnosed according to the criteria of the International Society of Geographical and Epidemiological Ophthalmology.

RESULTS

In subjects aged ≥ 40 years, prevalence rates of PEX syndrome, PEX without glaucoma and PEX-G in at least one eye were 1.5% (95% confidence interval [CI]: 1.0-1.9%), 1.3% (95% CI: 0.9-1.7%) and 0.1% (95% CI: 0.0-0.2%), respectively, excluding eyes after cataract surgery; and 2.8% (95% CI: 2.3-3.3%), 2.2% (95% CI: 1.8-2.6 %) and 0.4% (95% CI: 0.2-0.6%), respectively, including eyes after cataract surgery. Cataract surgery had been performed in 61% of subjects with PEX in at least one eye; presence of PEX showed no significant effects on the intraocular pressure (IOP). A multivariate analysis showed that PEX was associated with older age (p < 0.0001, odds ratio: 1.10 [95% CI: 1.07-1.13]) and working outdoors (p = 0.0395, odds ratio: 2.18 [95% CI: 0.99-4.82]).

CONCLUSIONS

The prevalence rates of PEX syndrome and PEX-G in a south-western island of Japan were reported. PEX showed no significant effect on IOP, and age and working outdoors were significantly related with PEX.

Metabolomic profiling of aqueous humor from glaucoma patients - The metabolomics in surgical ophthalmological patients (MISO) study

Glaucoma is still a poorly understood disease with a clear need for new biomarkers to help in diagnosis and potentially offer new therapeutic targets. We aimed to determine if the metabolic profile of aqueous humor (AH) as determined by nuclear magnetic resonance (NMR) spectroscopy allows the distinction between primary open-angle glaucoma patients and control subjects, and to distinguish between high-tension (POAG) and normal-tension glaucoma (NTG). We analysed the AH of patients with POAG, NTG and control subjects (n = 30/group). ¹H NMR spectra were acquired using a 400 MHz spectrometer. Principle component analysis (PCA), machine learning algorithms and descriptive statistics were applied to analyse the metabolic variance between groups, identify the spectral regions, and hereby potential metabolites that can act as biomarkers for glaucoma. According to PCA, fourteen regions of the NMR spectra were significant in explaining the metabolic variance between the glaucoma and control groups, with no differences found between POAG and NTG groups. These regions were further used in building a classifier for separating glaucoma from control patients, which achieved an AUC of 0.93. Peak integration was performed on these regions and a statistical analysis, after false discovery rate correction and adjustment for the different perioperative topical drug regimen, revealed that five of them were significantly different between groups. The glaucoma group showed a higher content in regions typical for betaine and taurine, possibly linked to neuroprotective mechanisms, and also a higher content in regions that are typical for glutamate, which can indicate damaged neurons and oxidative stress. These results show how aqueous humor metabolomics based on NMR spectroscopy can distinguish glaucoma patients from controls with a high accuracy. Further studies are needed to validate these results in order to incorporate them in clinical practice.

Association between Obstructive Sleep Apnea and Exfoliation Syndrome: The Utah Project on Exfoliation Syndrome

PURPOSE

Exfoliation syndrome (XFS), the most common recognizable cause of open-angle glaucoma worldwide, is a systemic disorder with genetic predisposition due to variations in lysyl oxidase-like 1 (LOXL1) function, leading to altered elastin matrices in ocular and systemic tissues. Obstructive sleep apnea (OSA) is a highly prevalent disorder also involving elastic tissue dysfunction and is associated with glaucoma. Because of the similarities between the disorders, we sought to uncover any relationship in the prevalence of these diagnoses.

DESIGN

Case-control, retrospective cohort study.

PARTICIPANTS

A cohort of 81 735 patients diagnosed with OSA at ages 50 to 90 years was identified from medical records from 1996 to 2017 in the Utah Population Database. Case subjects were matched to random controls on sex and birth year in a 4:1 ratio.

METHODS

International Classification of Diseases, Ninth Revision (ICD-9) codes or their Tenth Revision equivalent were used to define a diagnosis of OSA (ICD-9 327.23) and a diagnosis of XFS (ICD-9 365.52 and 366.11). Conditional logistic regression odds ratios (ORs) accounting for individual matching on sex and birth year were used to estimate the risk of XFS in patients with OSA. Models included adjustment for race, obesity, tobacco use, hypertension (HTN), atrial fibrillation (AF), and chronic obstructive pulmonary disease (COPD).

MAIN OUTCOME MEASURE

Whether patients with OSA have an increased risk of diagnosis of XFS compared with controls without OSA.

RESULTS

There was an increased risk of an XFS diagnosis in patients with OSA compared with non-OSA controls (OR, 1.27; 95% confidence interval [CI], 1.02-1.59; P = 0.03). In a stratification of patients by HTN diagnosis history, patients with OSA and HTN exhibited an increased risk of XFS compared with non-OSA controls with HTN (OR, 2.67; 95% CI, 2.06-3.46; P < 0.0001).

CONCLUSIONS

Patients with OSA may be at an increased risk of XFS compared with patients without OSA, particularly in patients with a history of HTN.

Epidemiology of Exfoliation Syndrome

BACKGROUND

From a historical standpoint the epidemiology of exfoliation syndrome (XFS) is one of the most controversial subjects in ophthalmic literature. Current literature abounds with studies on the prevalence of XFS in various ethnic populations and clearly XFS is a common condition, but its true prevalence is difficult to ascertain. Overall, XFS is considered to be the most common identifiable cause of glaucoma worldwide.

PURPOSE

This review critically examines the published literature documenting the epidemiological features of XFS and attempts to provide a unified concept concerning existing controversy.

METHODS

A critical review of selected literature pertaining to the epidemiology of XFS.

RESULTS

It is well established that XFS and the ensuing exfoliative glaucoma have a worldwide prevalence and a progressively increasing age-related incidence. The prevalence of the condition is significantly underestimated. Many past studies have proposed clear geographic variations within and between ethnic groups. In contrast, there has also been some epidemiological evidence suggesting that the prevalence of XFS is similar within various ethnic groups. Published literature fails to address the potential role and impact of suspected exfoliation cases in the reported prevalence figures of the condition. Incidence figures for the condition are limited and vary extensively. Cumulative data have indicated that several, as yet partly understood genetic, ethnic, and environmental factors contribute to the varied prevalence of this condition.

CONCLUSIONS

Further understanding on XFS epidemiology is needed. Only a future large prospective study conducted by the same investigators, using similar methodologies for different ethnic populations will prove beyond doubt the hypothesis that significant geographic variations exist. Since patients with exfoliative glaucoma are at significant risk of losing vision it is vital to elucidate the causes and the risk of developing XFS. To reach this goal, it is important to better delineate the early changes of XFS and to focus research efforts on modifiable factors for XFS development.

Factors Associated With Retinal Vessel Diameters in an Elderly Population: the Thessaloniki Eye Study

Purpose

To identify the factors associated with retinal vessel diameters in the population of the Thessaloniki Eye Study.

Methods

Cross-sectional population-based study (age ≥ 60 years). Subjects with glaucoma, late age-related macular degeneration, and diabetic retinopathy were excluded from the analyses. Retinal vessel diameters were measured using the IVAN software, and measurements were summarized to central retinal artery equivalent (CRAE), central retinal vein equivalent (CRVE), and arteriole to venule ratio (AVR).

Results

The analysis included 1614 subjects. The hypertensive group showed lower values of CRAE (P = 0.033) and AVR (P = 0.0351) compared to the normal blood pressure (BP) group. On the contrary, the group having normal BP under antihypertensive treatment did not have different values compared to the normal BP group. Diastolic BP (per mm Hg) was negatively associated with CRAE (P < 0.0001) and AVR (P < 0.0001), while systolic BP (per mm Hg) was positively associated with CRAE (P = 0.001) and AVR (P = 0.0096). Other factors significantly associated included age, sex, alcohol, smoking, cardiovascular disease history, ophthalmic medication, weight, and IOP; differences were observed in a stratified analysis based on BP medication use.

Conclusions

Our study confirms previous reports about the association of age and BP with vessel diameters. The negative correlation between BP and CRAE seems to be guided by the effect of diastolic BP as higher systolic BP is independently associated with higher values of CRAE. The association of BP status with retinal vessel diameters is determined by diastolic BP status in our population. Multiple other factors are also independently associated with retinal vessel diameters.

Twelve-Year Incidence and Baseline Risk Factors for Pseudoexfoliation: The Thessaloniki Eye Study (An American Ophthalmological Society Thesis)

PURPOSE

To determine the 12-year incidence of pseudoexfoliation (PEX), baseline risk factors for incident PEX and risk factors for incident pseudoexfoliative glaucoma (PEXG) among those with PEX in an elderly white population.

METHODS

Longitudinal, population-based study in Thessaloniki, the major urban center in Northern Greece. The baseline cohort included 2554 participants ≥60 years old. The surviving cohort was re-examined 12 years later using the same methodology. PEX was defined as typical fibrillar material at the pupil margin and/or on the lens capsule. Glaucoma was defined as both structural and functional damage, irrespective of intraocular pressure (IOP).

RESULTS

Of 1468 eligible subjects in the surviving cohort, 1092 (74%) participated in the follow-up study. The mean age ± standard deviation (SD) at baseline was 68.9 ± 4.6 years. The mean follow-up time was 11.6 ± 1.6 years. The 12-year incidence of PEX was 19.6% (95% confidence interval (CI), 17.1-22.2), with women more likely to be affected than men (Fisher's exact test, P = .0197). Higher axial length was associated with lower odds of incident PEX (odds ratio [OR], 0.72 per mm; 95% CI, 0.57-0.92). PEX at baseline was not associated with an increased likelihood of major vascular disease (P = .9038). Higher baseline IOP (OR, 1.26 per mm Hg; 95% CI, 1.07-1.48) and history of heart attack at baseline (OR, 13.49; 95% CI, 2.85-63.87) were associated with a greater likelihood of developing PEXG among those with PEX. A history of alcohol consumption at baseline was protective of individuals developing PEXG if they had PEX at baseline.

CONCLUSION

This is one of the very few longitudinal population-based studies that has specifically assessed the incidence of PEX. The association with axial length was previously found only in a cross-sectional study. The associations with heart attack and alcohol consumption are new findings. In individuals with baseline PEX, higher IOP at baseline, history of heart attack at baseline, and no alcohol consumption were associated with a greater likelihood of developing glaucomatous damage approximately 12 years later. NOTE: Publication of this article is sponsored by the American Ophthalmological Society.

Prevalence of treatment with glaucoma medication in Scotland, 2010-2017

AIMS

To report the number and demographic distribution of patients receiving intraocular pressure (IOP)-lowering medications across the whole population of Scotland for the years 2010-2017 and, using national census data, show how the observed changes compare with those predicted by the increasing age of the population structure over this period.

METHODS

Data were sourced from the Prescribing Information System of the NHS Information and Statistics Division for Scotland. The number of patients dispensed any IOP-lowering medication from a community pharmacy during each calendar year was collected by gender and by 5-year age bands. National census data were used to model the expected annual increase in treatment numbers due to population ageing.

RESULTS

The number of treated patients in 2017 was 61 249 which represents 1.13% of the whole population (or 2.16% over 40 years of age). The number increased from 48 178 in 2010-an increase over this period of 27.13% (3.88% per year).Prevalence increased with age, reaching 10.67% in those over 90 years. After age adjustment, more men were treated than women (OR 1.26).The expected number treated in 2017 based on census predictions was 54 075 (an increase of 5897 (12.24%) from 2010). The observed growth of 27.13% was 2.22-fold greater than the rate expected by population changes over the period 2010-2017.

CONCLUSION

The number of patients on medication for glaucoma and ocular hypertension in Scotland is increasing. The rate of increase cannot be explained by changes in the size and age structure of the population alone.

Overdiagnosis of open-angle glaucoma in the general population: the Thessaloniki Eye Study

PURPOSE

To assess the overdiagnosis of open-angle glaucoma (OAG) and to investigate associated factors.

METHODS

This was a cross-sectional, population-based study of an urban Caucasian population in northern Greece. Randomly selected subjects ≥60 years (n = 2554) participated in the Thessaloniki Eye Study. The definition of OAG required the presence of structural and functional damage, irrespective of intraocular pressure (IOP). Non-OAG subjects were classified as overdiagnosed with OAG if they had reported at least one of the following (self-reported glaucoma): (i) prior diagnosis of glaucoma, (ii) prior laser for glaucoma, (iii) prior glaucoma surgery. Factors associated with the overdiagnosis of OAG were investigated using a logistic regression model.

RESULTS

Of 57 (2.2%) subjects with self-reported glaucoma, 34 (60%) were overdiagnosed with OAG, corresponding to a prevalence of 1.3% (34/2554). In a logistic regression model among non-OAG subjects, worse visual acuity (VA) (20/200 or worse versus 20/25 or better; odds ratio (OR) = 4.30, 95% Confidence Intervals (CI), 1.13-16.35), family history of glaucoma (OR = 8.69, 95% CI, 2.83-26.67) and history of cataract surgery (OR = 11.50, 95% CI, 3.85-34.36) were statistically significantly associated with the overdiagnosis of OAG. Age, sex, higher IOP, higher vertical cup-to-disc ratio and pseudoexfoliation were not statistically significant.

CONCLUSION

The overdiagnosis of OAG was substantial in this elderly, Caucasian population. The overdiagnosis of glaucoma has not been previously addressed in population-based studies and needs to be further explored.

Risk factors for Age-related Macular Degeneration in a Greek population: The Thessaloniki Eye Study

PURPOSE

To assess the association of potential risk factors with early and late age-related macular degeneration (AMD) in the Thessaloniki Eye Study (TES) population Design: Population-based, cross-sectional study of subjects over age of 60 living in Thessaloniki, Greece Methods: Subjects without any AMD features and subjects with early and late AMD (neovascular AMD or geographic atrophy) were identified in the TES cohort using standardized procedures and masked grading of stereo color fundus photos. Demographic, lifestyle, systemic and other ophthalmic covariates were also collected during a detailed examination process. Their association with AMD was investigated using univariate and multivariate adjusted logistic regression models.

RESULTS

Among the 2108 participants with gradable photos, the grading process identified 1204 subjects with no AMD, 848 subjects with early AMD, and 56 subjects with late AMD (24 with geographic atrophy and 32 with neovascular AMD). In multivariate analysis, compared to no AMD, late AMD was positively associated with older age (OR:1.16; 95%CI:1.10-1.22 per year of age), current smoking (smoking vs. never smoking, OR:2.34; 95%CI:1.12-4.90), prior cataract surgery (cataract surgery vs. no cataract surgery OR:2.06; 95%CI:0.96-4.40), marital status (divorced/separated vs. married, OR:3.10; 95%CI:1.08-8.93) and with 60% lower odds when sleeping in the afternoon (yes vs. no, OR:0.40; 95%CI:0.22-0.72). Early AMD was positively associated with older age (OR: 1.03; 95%CI:1.01-1.05 per year of age) and negatively with higher pulse pressure (OR:0.99; 95%CI:0.98-0.99 per mmHg).

CONCLUSIONS

In TES, apart for well-known risk factors for AMD like age, smoking, and cataract surgery, two novel behavioral risk factors for prevalent late AMD were suggested. Sleeping in the afternoon was associated with 60% decreased odds for late AMD and 67% decreased odds for neovascular AMD. Being divorced/separated compared to married was associated with 3-fold higher odds for late AMD. Large longitudinal population-based studies will be necessary to further establish the potential late AMD risk effects of these two novel factors, to demonstrate potential implications of underlying pathogenetic mechanisms, and to explore preventive measures and therapeutic targets.

Prevalence and risk factors of glaucoma in an adult population from Shahroud, Iran

Purpose

To determine the prevalence of glaucoma and its risk factors in a 40- to 64-year-old Iranian population.

Methods

In this cross-sectional study, 6311 individuals between the ages of 40–64 years old in Shahroud, a northeastern city in Iran, were selected through multistage cluster sampling. All participants underwent eye exams, optometry, and imaging. They had stereoscopic optic disc photography, visual field evaluation, and their intraocular pressure (IOP) was measured by ophthalmologists before pupil dilation. Glaucoma was defined by the standardized criteria, offered by the International Society for Geographical and Epidemiological Ophthalmology (ISGEO).

Results

Of the 5190 people who participated in the study (82.2%), data from 4637 people were used in the analysis. The prevalence of glaucoma was 1.92% [95% confidence intervals (CI): 1.53–2.31]; 1.4% (95% CI: 0.96–1.84) in women and 2.62% (95% CI: 1.95–3.28) in men. Glaucoma prevalence was 0.9% in the 40–44 years age group, and significantly increased to 3.55% in the 60–64 years age group. In the multiple logistic regression model, age [odds ratio (OR) = 1.08, 95% CI: 1.05–1.12], IOP (OR = 1.04, 95% CI: 1.01–1.06), axial length (OR = 1.34, 95% CI: 1.1–1.63), corneal radius of curvature (OR = 2.76, 95% CI: 1.26–6.06), and corneal diameter (OR = 0.63, 95% CI: 0.46–0.87) showed significant statistical association with glaucoma.

Conclusions

The prevalence of glaucoma was considerably high at older ages. Major risk factors confirmed by this study included older age and high IOP. Certain ocular biometric components such as the axial length and the corneal radius of curvature must be noted as important glaucoma risk factors at younger ages.

Genome-wide analyses identify 68 new loci associated with intraocular pressure and improve risk prediction for primary open-angle glaucoma

Glaucoma is the leading cause of irreversible blindness globally 1 . Despite its gravity, the disease is frequently undiagnosed in the community 2 . Raised intraocular pressure (IOP) is the most important risk factor for primary open-angle glaucoma (POAG)3,4. Here we present a meta-analysis of 139,555 European participants, which identified 112 genomic loci associated with IOP, 68 of which are novel. These loci suggest a strong role for angiopoietin-receptor tyrosine kinase signaling, lipid metabolism, mitochondrial function and developmental processes underlying risk for elevated IOP. In addition, 48 of these loci were nominally associated with glaucoma in an independent cohort, 14 of which were significant at a Bonferroni-corrected threshold. Regression-based glaucoma-prediction models had an area under the receiver operating characteristic curve (AUROC) of 0.76 in US NEIGHBORHOOD study participants and 0.74 in independent glaucoma cases from the UK Biobank. Genetic-prediction models for POAG offer an opportunity to target screening and timely therapy to individuals most at risk.

Prevalence of glaucoma in Germany: results from the Gutenberg Health Study

PURPOSE

To determine the prevalence of glaucoma according to the International Society for Geographical and Epidemiological Ophthalmology (ISGEO) classification in an adult German cohort.

METHODS

The Gutenberg Health Study is a population-based, prospective cohort study in the Rhine-Main Region in mid-western Germany with a total of 15,010 participants. In this study, the first 5000 subjects with an age range between 35 and 74 years were included. Optic disk pictures were obtained by a non-mydriatic fundus camera (Visucam™) and analyzed using the Visupac™ software. Glaucoma prevalence was determined in two steps. First, the ISGEO classification was applied using "hypernormal subjects" (normal visual field) as reference. In the second analysis, we additionally considered the disk area (DA) in relation to the vertical cup-to-disk ratio by quantile regression. All results are given as weighted numbers for the population of Mainz/Bingen.

RESULTS

The prevalence of definite glaucoma in our sample was 1.44% (n = 72). The prevalence adjusted for disk area was 1.34% (n = 67). The prevalence gradually increased in both models with each decade of age (from 0.9 to 2.4%, respectively). In both models, none of the glaucoma cases had a small optic disk (< 1.6 mm²). Glaucoma prevalence in medium optic disks was 1.0% (without DA adjustment) vs. 1.6% (with DA adjustment) and in large optic disks 5.6 vs. 2.5%.

CONCLUSIONS

The prevalence of definite glaucoma was similar to other European population-based cohorts, with slightly higher prevalence in younger subjects. Our analysis highlighted the influence of optic disk size in determining the diagnosis of glaucoma based on cup-to-disk ratio in epidemiological studies.

Glaucoma suspects: A practical approach

Glaucoma suspects are controversial clinical dilemmas. These individuals harbor certain risk factors or demonstrate some clinical features suggestive of an increased probability to develop glaucomatous optic atrophy in the future. These characteristics range from high intraocular pressure; optic disc, visual field, or retinal nerve fiber layer abnormalities; or abnormal angles to a positive family history of glaucoma and other risk factors. Individuals having these characteristics should be assessed diligently before a diagnosis of glaucoma is made. Glaucoma is a chronic, lifelong condition, having a negative impact on the quality of life, with an increased risk of medication-related side-effects, adverse economic impacts, and the need for lifestyle changes in the patient. Overdiagnosis and unnecessary treatment of such individuals is bereft of any advantage. This review aims to provide a practical blueprint for the proper diagnosis and management of such glaucoma suspects.

Efficacy of a Deep Learning System for Detecting Glaucomatous Optic Neuropathy Based on Color Fundus Photographs

PURPOSE

To assess the performance of a deep learning algorithm for detecting referable glaucomatous optic neuropathy (GON) based on color fundus photographs.

DESIGN

A deep learning system for the classification of GON was developed for automated classification of GON on color fundus photographs.

PARTICIPANTS

We retrospectively included 48 116 fundus photographs for the development and validation of a deep learning algorithm.

METHODS

This study recruited 21 trained ophthalmologists to classify the photographs. Referable GON was defined as vertical cup-to-disc ratio of 0.7 or more and other typical changes of GON. The reference standard was made until 3 graders achieved agreement. A separate validation dataset of 8000 fully gradable fundus photographs was used to assess the performance of this algorithm.

MAIN OUTCOME MEASURES

The area under receiver operator characteristic curve (AUC) with sensitivity and specificity was applied to evaluate the efficacy of the deep learning algorithm detecting referable GON.

RESULTS

In the validation dataset, this deep learning system achieved an AUC of 0.986 with sensitivity of 95.6% and specificity of 92.0%. The most common reasons for false-negative grading (n = 87) were GON with coexisting eye conditions (n = 44 [50.6%]), including pathologic or high myopia (n = 37 [42.6%]), diabetic retinopathy (n = 4 [4.6%]), and age-related macular degeneration (n = 3 [3.4%]). The leading reason for false-positive results (n = 480) was having other eye conditions (n = 458 [95.4%]), mainly including physiologic cupping (n = 267 [55.6%]). Misclassification as false-positive results amidst a normal-appearing fundus occurred in only 22 eyes (4.6%).

CONCLUSIONS

A deep learning system can detect referable GON with high sensitivity and specificity. Coexistence of high or pathologic myopia is the most common cause resulting in false-negative results. Physiologic cupping and pathologic myopia were the most common reasons for false-positive results.

The Prevalence of Pseudoexfoliation and the Long-term Changes in Eyes With Pseudoexfoliation in a South Indian Population

PURPOSE

To report the prevalence, long-term changes and associated factors for pseudoexfoliation (PEX) in a population aged 40 years and above from rural and urban south India.

MATERIALS AND METHODS

At baseline (the Chennai Glaucoma Study), 7774 subjects were examined. After 6 years, as a part of the incidence study, 133 of the 290 subjects diagnosed with PEX at baseline were reexamined for long-term changes. Participants had detailed examination at base hospital.

RESULTS

At baseline PEX was noted in 290 [3.73%, 95% confidence interval (CI), 3.3-4.2] subjects. It was associated with glaucoma in 24 (8.3%), ocular hypertension (OHT) in 21 (7.2%), and occludable angles in 24 (8.3%) subjects. The age-adjusted and sex-adjusted prevalence was 3.41% (95% CI, 3.39-3.43). Increasing age was a significant associated factor. Using the 40- to 49-year age group as a reference, the odds ratio increased from 8.4 (95% CI, 4.1-17.1) for the 50- to 59-year age group to 51.2 (95% CI, 25.8-101.6) for the 70 years and above age group. Other associated factors were rural residence (P<0.001), higher intraocular pressure (P<0.001), cataract (P<0.001), being underweight (P=0.01), manual labor (P=0.03), and aphakia (P<0.001). Of the 133 subjects reexamined, 8 (6.0%) subjects developed glaucoma and all had OHT at baseline. Rates of cataract surgery were (P<0.001) higher in subjects with PEX.

CONCLUSION

Prevalence of PEX was higher in rural population and baseline OHT was a significant factor for conversion to glaucoma.

Tolerable rates of visual field progression in a population-based sample of patients with glaucoma

AIMS

To provide population-based data on the maximum tolerable rate of progression to avoid visual impairment (maxTRoP_VI) and blindness (maxTRoP_BL) from open-angle glaucoma (OAG).

METHODS

Participants with OAG in the Thessaloniki Eye Study (cross-sectional, population-based study in a European population) were included in the analysis. Visual impairment was defined as mean deviation (MD) equal to or worse than -12dB and blindness as MD equal to or worse than -24dB. Additional thresholds for visual impairment were tested. For each participant maxTRoP_VI was defined as the rate of progression which would not lead to visual impairment during expected lifetime. MaxTRoP_BL was defined accordingly. Both parameters were calculated for each OAG subject using age, sex, MD and life expectancy data. The eye with the better MD per subject was included in the analysis.

RESULTS

Among 135 subjects with OAG, 123 had reliable visual fields and were included in the analysis. The mean age was 73±6 years and the median MD was -3.65±5.28dB. Among those, 69.1% would have a maxTRoP_VI slower than -1dB/year and 18.7% would have a maxTRoP_VI between -1 and -2dB/year. Also, 72.4% would have a maxTRoP_BL slower than -2dB/year. For all tested thresholds for visual impairment, approximately 86% of the OAG study participants would not be able to tolerate a rate of progression equal to or faster than -2dB/year.

CONCLUSIONS

The majority of patients with glaucoma in our study would have a maximum tolerable rate of progression slower than -1dB/year in their better eye. Patient-tailored strategies to monitor the visual field are important, but raise the issue of feasibility with regard to the number of visual field tests needed.

Glaucoma and intraocular pressure in EPIC-Norfolk Eye Study: cross sectional study

Objectives To report the distribution of intraocular pressure (IOP) by age and sex and the prevalence of glaucoma.Design Community based cross sectional observational study.Setting EPIC-Norfolk cohort in Norwich and the surrounding rural and urban areas.Participants 8623 participants aged 48-92 recruited from the community who underwent ocular examination to identify glaucoma.Main outcome measures Prevalence and characteristics of glaucoma, distribution of IOP, and the sensitivity and specificity of IOP for case finding for glaucoma.Results The mean IOP in 8401 participants was 16.3 mm Hg (95% confidence interval 16.2 mm Hg to 16.3 mm Hg; SD 3.6 mm Hg). In 363 participants (4%), glaucoma was present in either eye; 314 (87%) had primary open angle glaucoma. In the remaining participants, glaucoma was suspected in 607 (7%), and 863 (10.0%) had ocular hypertension. Two thirds (242) of those with glaucoma had previously already received the diagnosis. In 76% of patients with newly diagnosed primary open angle glaucoma (83/107), the mean IOP was under the threshold for ocular hypertension (21 mm Hg). No one IOP threshold provided adequately high sensitivity and specificity for diagnosis of glaucoma.Conclusions In this British community, cases of glaucoma, suspected glaucoma, and ocular hypertension represent a large number of potential referrals to the hospital eye service. The use of IOP for detection of those with glaucoma is inaccurate and probably not viable.

Prospective study of glaucoma referrals across Europe: are we using resources wisely?

BACKGROUND

To investigate the outcomes of glaucoma referrals across different European countries.

METHODS

250 patients newly referred to tertiary referral glaucoma specialist practices in the UK, Hungary, Slovenia, Italy and Greece were prospectively enrolled (50 consecutive patients per centre). Referral accuracy and predictive value of referral criteria for an intervention or further monitoring (positive predictive value) were analysed.

RESULTS

Same-day discharges occurred in 43% (95% CI 39% to 75%) (12/28) of optometrist-initiated referrals (UK only), 37% (95% CI 30% to 45%) (59/158) of ophthalmologist-initiated referrals (all centres) and 54% (95% CI 40% to 68%) (26/48) of self-referrals (Hungary, Italy and Greece). The percentages from all referral sources were 46% (95% CI 32% to 60%) in the UK, 56% (95% CI 44% to 70%) in Hungary, 30% (95% CI 17% to 43%) in Slovenia, 22% (95% CI 11% to 34%) in Italy and 60% (95% CI 46% to 74%) in Greece (p<0.001). Overall, the referring criterion was confirmed in 54% (95% CI 45% to 63%) (64/119) for intraocular pressure (IOP) >21 mm Hg, 56% (95% CI 43% to 69%) (33/59) for a suspicious optic disc and 61% (95% CI 45% to 77%) (22/36) for a suspicious visual field, with large between-country differences (p<0.05 for all comparisons). Of all referrals, 32% (95% CI 26% to 37%) were initiated on the basis of IOP >21 mm Hg only. By combining the IOP criterion with any other referring criterion, the positive predictive value increased from 56% (95% CI 45% to 67%) to at least 89% (95% CI 68% to 100%). In the UK, a hypothetical IOP threshold of >26 mm Hg, as a requirement for IOP-only referrals, would reduce IOP-only referrals by 44%, while not missing any definite glaucoma cases.

CONCLUSION

The accuracy of referrals was poor in the UK and the other countries. Requiring a combination of criteria and raising the IOP threshold for IOP-only referrals are needed to cut waste in clinical care.

Immunohistochemical Profiles of LOXL-1, FBN1, TGF-β1, and COX-2 in Pseudoexfoliation Syndrome

PURPOSES

To (i) determine expression patterns of lysyl oxidase-like 1 (LOXL1), fibrillin-1 (FBN1), transforming growth factor beta-1 (TGF-β1), and cyclooxygenase-2 (COX-2) in lens epithelium and anterior lens capsule in pseudoexfoliation (PEX) syndrome and (ii) delineate the roles of these proteins in the etiopathogenesis of PEX.

MATERIALS AND METHODS

Study participants, all of whom had undergone cataract surgery, comprised 47 patients with and 27 patients without (controls) PEX syndrome. Immunohistochemistry on paraffin sections of lens capsule and lens epithelium was performed.

RESULTS

Immunoexpression of LOXL1 and FBN1 on the outer surface of the lens capsule was significantly higher (p < 0.001), and nuclear immunopositivity for LOXL1 was more frequently observed (p = 0.017), in PEX patients compared with control patients. Cytoplasmic expression of LOXL1 and COX-2 was significantly lower (p = 0.015 and p = 0.042, respectively) in PEX patients compared with controls. TGF-β1 exhibited diffuse immunostaining detected in all cell layers in PEX patients (p <0.001). Significant direct correlations of cytoplasmic LOXL1 with FBN1 and TGF-β1, and of COX-2 with FBN1, TGF-β1, and LOXL-1, were observed only in PEX patients.

CONCLUSIONS

Results of our study provide valuable information vis-à-vis expression and localization of TGF-β1, LOXL1, and FBN1, as well as their associations in the lens epithelium and lens capsule. These data not only advance our knowledge of the etiopathogenesis of PEX syndrome, but also include novel findings, for example, immunostaining patterns of TGF-β1 in PEX syndrome. We suggest that COX-2 plays a role in the pathobiology of PEX syndrome and should be the subject of future investigations.