Blindness and Glaucoma: A Multicenter Data Review from 7 Academic Eye Clinics

RNFLT2Vec: Artifact-corrected representation learning for retinal nerve fiber layer thickness maps

Optical coherence tomography imaging provides a crucial clinical measurement for diagnosing and monitoring glaucoma through the two-dimensional retinal nerve fiber layer (RNFL) thickness (RNFLT) map. Researchers have been increasingly using neural models to extract meaningful features from the RNFLT map, aiming to identify biomarkers for glaucoma and its progression. However, accurately representing the RNFLT map features relevant to glaucoma is challenging due to significant variations in retinal anatomy among individuals, which confound the pathological thinning of the RNFL. Moreover, the presence of artifacts in the RNFLT map, caused by segmentation errors in the context of degraded image quality and defective imaging procedures, further complicates the task. In this paper, we propose a general framework called RNFLT2Vec for unsupervised learning of vectorized feature representations from RNFLT maps. Our method includes an artifact correction component that learns to rectify RNFLT values at artifact locations, producing a representation reflecting the RNFLT map without artifacts. Additionally, we incorporate two regularization techniques to encourage discriminative representation learning. Firstly, we introduce a contrastive learning-based regularization to capture the similarities and dissimilarities between RNFLT maps. Secondly, we employ a consistency learning-based regularization to align pairwise distances of RNFLT maps with their corresponding thickness distributions. Through extensive experiments on a large-scale real-world dataset, we demonstrate the superiority of RNFLT2Vec in three different clinical tasks: RNFLT pattern discovery, glaucoma detection, and visual field prediction. Our results validate the effectiveness of our framework and its potential to contribute to a better understanding and diagnosis of glaucoma.

Cost-effectiveness analysis of prophylactic laser peripheral iridotomy for primary angle-closure suspect in Japan

BACKGROUND/OBJECTIVES

This study aimed to compare the cost-effectiveness of prophylactic laser peripheral iridotomy (LPI) with that of observation for primary angle-closure suspect (PACS) in Japan.

SUBJECTS/METHODS

A Markov model was developed to compare the costs and utilities of prophylactic LPI with those of observation of 40-year-old patients with PACS. In the model with a yearly cycle over a 20-year time horizon, the disease was postulated to irreversibly progress from PACS to primary angle closure, followed by primary angle-closure glaucoma, unilateral blindness, and bilateral blindness. The parameters were estimated mainly based on a recent randomised controlled trial and analyses of Japanese claims data. The incremental cost-effectiveness ratio was estimated from the healthcare payer's perspective and evaluated at the willingness-to-pay 5 million Japanese Yen per quality-adjusted life-year. The observation period and the age at entry into the cohort was changed to account for a variety of clinical courses in sensitivity analyses. We conducted one-way deterministic sensitivity analysis and probabilistic sensitivity analysis with Monte Carlo simulations with 10 000 iterations.

RESULTS

The incremental cost-effectiveness ratio of LPI was 2,287,662 Japanese Yen (14,298 pounds sterling) per quality-adjusted life-year, which was below the willingness-to-pay threshold. The ratios were approximately 4 and 8 million in the 15-year and 10-year time horizons, respectively. Increasing the age at entry had little influence on the incremental cost-effectiveness ratio. The deterministic and probabilistic sensitivity analyses indicated that the results were robust.

CONCLUSIONS

Our results indicate that prophylactic LPI for middle-aged patients with PACS is cost-effective in Japan.

Clinical risk stratification in glaucoma

Glaucoma is the leading cause of preventable sight loss in the United Kingdom and the provision of timely glaucoma care has been highlighted as a significant challenge in recent years. Following a recent high-profile investigation, The Healthcare Safety Investigation Branch recommended the validation of risk stratification models to safeguard the vision-related quality of life of glaucoma patients. There continues to be no nationally agreed evidence-based risk stratification model for glaucoma care across the United Kingdom. Some models have used simple measures of disease staging such as visual field mean deviation as surrogates for risk, but more refined, individualised risk stratification models should include factors related to both visual impairment and visual disability. Candidate tools should also incorporate both ocular and systemic co-morbidities, rate of disease progression, visual needs and driving status and undergo clinical refinement and validation to justify implementation. The disruption to routine glaucoma care caused by the COVID-19 pandemic has only highlighted the importance of such risk stratification models and has accelerated their development, application and evaluation. This review aims to critically appraise the available evidence underpinning current approaches for glaucoma risk stratification and to discuss how these may be applied to contemporary glaucoma care within the United Kingdom. Further research will be essential to justify and validate the utility of glaucoma risk stratification models in everyday clinical practice.

Immunomodulatory and Antioxidant Drugs in Glaucoma Treatment

Glaucoma, a group of diseases characterized by progressive retinal ganglion cell loss, cupping of the optic disc, and a typical pattern of visual field defects, is a leading cause of severe visual impairment and blindness worldwide. Elevated intraocular pressure (IOP) is the leading risk factor for glaucoma development. However, glaucoma can also develop at normal pressure levels. An increased susceptibility of retinal ganglion cells to IOP, systemic vascular dysregulation, endothelial dysfunction, and autoimmune imbalances have been suggested as playing a role in the pathophysiology of normal-tension glaucoma. Since inflammation and oxidative stress play a role in all forms of glaucoma, the goal of this review article is to present an overview of the inflammatory and pro-oxidant mechanisms in the pathophysiology of glaucoma and to discuss immunomodulatory and antioxidant treatment approaches.

Comparison between the Recommendations of Glaucoma Specialists and OCT Report Specialists for Further Ophthalmic Evaluation in a Community-Based Screening Study

PURPOSE

To compare glaucoma referral patterns between glaucoma and OCT report specialists and to determine what influence, if any, a designated OCT reading could have on a glaucoma specialist's judgments.

DESIGN

Retrospective, exploratory study.

SUBJECTS

We included 483 eyes (243 individuals) from high-risk New York City neighborhoods screened as part of a mobile van glaucoma screening study from July 2017 to October 2017.

METHODS

All participants underwent comprehensive testing, including visual acuity, commercial OCT imaging, gonioscopy, intraocular pressure, frequency-doubling testing, and funduscopic assessment. Three glaucoma specialists independently evaluated all the collected data to determine whether a further glaucoma workup referral was recommended. Two OCT report specialists evaluated only the OCT image for each eye using the commercial report as well as a specialized, customized report. In phase II, the glaucoma specialists then re-evaluated a subset of these eyes, this time with an OCT report specialist's judgments made available.

MAIN OUTCOME MEASURES

Comparison of glaucoma specialist referrals made by glaucoma specialists versus OCT report specialists.

RESULTS

Intergrader agreement between glaucoma specialists was 60% (κ = 0.43) and between report specialists was 95% (κ = 0.77). There was an agreement between a single OCT report specialist and the consensus (2 of 3) of glaucoma specialists in 74% of eyes (κ= 0.32). Of the eyes studied, 25% were referred for further glaucoma evaluation by the glaucoma specialists alone and 1% were referred for further glaucoma workup by only the report specialist. With the addition of the report specialist's judgments, referral pattern changes varied by glaucoma specialist but overall agreement increased to 85% (κ = 0.53).

CONCLUSIONS

There was a fair level of agreement regarding glaucoma referral recommendations between glaucoma specialists with access to comprehensive screening data and OCT report specialists with access to only OCT data. Overall agreement increased when the designated OCT evaluation was made available to the glaucoma specialists. These results may aid in the design of future large-scale glaucoma screening studies.

Heat Shock Protein Upregulation Supplemental to Complex mRNA Alterations in Autoimmune Glaucoma

Glaucomatous optic neuropathy is a common cause for blindness. An elevated intraocular pressure is the main risk factor, but also a contribution of the immune system seems likely. In the experimental autoimmune glaucoma model used here, systemic immunization with an optic nerve homogenate antigen (ONA) leads to retinal ganglion cell (RGC) and optic nerve degeneration. We processed retinae for quantitative real-time PCR and immunohistology 28 days after immunization. Furthermore, we performed mRNA profiling in this model for the first time. We detected a significant RGC loss in the ONA retinae. This was accompanied by an upregulation of mRNA expression of genes belonging to the heat shock protein family. Furthermore, mRNA expression levels of the genes of the immune system, such as C1qa, C1qb, Il18, and Nfkb1, were upregulated in ONA animals. After laser microdissection, inner retinal layers were used for mRNA microarrays. Nine of these probes were significantly upregulated in ONA animals (p < 0.05), including Hba-a1 and Cxcl10, while fifteen probes were significantly downregulated in ONA animals (p < 0.05), such as Gdf15 and Wwox. Taken together, these findings provide further insights into the pivotal role of the immune response in glaucomatous optic neuropathy and could help to identify novel diagnostic or therapeutic strategies.

Rho Kinase Inhibitors as a Neuroprotective Pharmacological Intervention for the Treatment of Glaucoma

Glaucoma is a leading cause of irreversible blindness, and its prevalence has led to research into treatment modalities for glaucoma to prevent the progression of the disease. The primary treatment for glaucoma that has been extensively used is ocular hypotensives to reduce raised intraocular pressure. This treatment has its drawbacks due to the existence of other variants of glaucoma, such as normal-tension glaucoma, where the intraocular pressure is measured to be within regular levels. Hence, there is a need for new treatment interventions which can deliver a better prognosis for glaucoma. Neuroprotection is a new concept studied recently, and neuroprotective agents are being developed for glaucoma therapy. Rho kinase inhibitors are one such neuroprotective agent, and the most recent addition to the class of ocular hypotensives, where they function by reducing raised intraocular pressure. Its neuroprotective capabilities, such as cell survival and axon regeneration, are yet to be determined in detail. This literature review article aims to look into the need for new treatments such as neuroprotection to prevent the progression of glaucoma and the efficacy of rho kinase inhibitors in the treatment of glaucoma, with particular emphasis on its neuroprotective abilities. It also aims to identify the limitations that can occur while approaching neuroprotective therapy, as well as how it can enable future treatment modalities. By exploring this field, blindness caused by progressive glaucoma can be halted and managed by glaucoma therapy.

Study to Identify and Evaluate Predictor Factors for Primary Open-Angle Glaucoma in Tertiary Prophylactic Actions

The aim of this study is to develop a predictive model with several explanatory variables that can guide ophthalmologists to make a more objective assessment of the evolution of open-angle glaucoma (OAG) during tertiary prevention. Objectives: The evaluation of risk factors and different predictors of symptom progression between patients with POAG and non-glaucoma patients (NG), as well as between primary open-angle glaucoma with high intraocular pressure (POAG) and primary open-angle glaucoma with normal intraocular pressure (NTG), in tertiary prophylactic activities. Methods: This research is an analytical epidemiological study of a prospective cohort. For the study, we took into account personal medical history, physical ophthalmological examination, intraocular pressure (IOP) values, and visual field (VF) parameters, examined with the Opto AP-300 Automated Perimeter using the “fast threshold” strategy. The results of gonioscopy were inconsistently recorded; they were not considered in the study due to missing values, the processing of which would have seriously distorted the statistical analysis. Ophthalmological examination was completed with a dichotomous questionnaire entitled “Symptom Inventory”, made according to the accusations of patients resulting from a “focus group” study. The study was carried out in the ophthalmology office within the Integrated Outpatient Clinic of the Emergency Clinical Hospital of Oradea, Bihor County (IOCECHO) between January−December 2021. The threshold of statistical significance was defined for p value < 0.05. The obtained results were statistically processed with specialized software SPSS 22. Results: The study included 110 people, of which 71 (64.54%) had POAG (IOP > 21 mmHg) and 39 people (35.46%) had NTG (IOP < 21 mmHg), the two groups being statistically significantly different (χ2 = 9.309, df = 1, p = 0.002). For the POAG group, glaucomatous loss was early, AD < −6 dB, according to the staging of glaucomatous disease, HODAPP classification. In addition, the groups of POAG and NTG patients was compared with a group of 110 NG patients, these three groups being statistically significantly different (χ2 = 34.482, df = 2, p = 0.000). Analysis of confounding factors (age, sex, residence, marital status) shows a statistically significant relationship only for age (F = 2.381, df = 40, p = 0.000). Sex ratio for the study groups = 5.11 for OAG and =5.87 for NG. After treatment (prostaglandin analogues and neuroprotective drugs) IOP decreased statistically significantly for both POAG and NTG. Conclusions: this study identified possible predictors of OAG, at the 5% level (risk factors and symptoms as independent variables) using a dichotomous questionnaire tool with a complementary role in tertiary prophylactic activities. The implementation of the focus group interview results as a socio-human research technique will be supportive to clinicians.

Investigation of Biomedical Students' Knowledge on Glaucoma Reveals a Need for Education: A Cross-Sectional Study

Background: Glaucoma has been recognized as one of the leading global causes of irreversible blindness. Patients with primary open-angle glaucoma rarely present with visual symptoms, at least early in the course of the disease. It is important to recognize and treat the disease before there are irreversible changes. Methods: This cross-sectional study was conducted at the University of Split School of Medicine from October to November 2021. Participants were biomedical students who completed a questionnaire. Results: In total, 312 students participated in this study. Interestingly, only 12.2% of students identified that primary open-angle glaucoma was asymptomatic. Only 42.6% of all students recognized glaucoma as being the main cause of irreversible blindness. Pharmacy students less frequently recognized high blood pressure and diabetes mellitus as risk factors for glaucoma. Students who completed an ophthalmology course more frequently recognized that successful glaucoma treatment prevents blindness, compared to students who did not complete the course, 79.1% vs. 48.7%, p < 0.001. Conclusion: The results showed that students’ knowledge on the subject is low, even after they passed their ophthalmology course. However, knowledge of glaucoma is crucial for early disease identification and the prevention of blindness. Therefore, it is important that all future health care professionals acquire adequate education.

Modeling Time to Blindness of Glaucoma Patients: A Case Study at Jimma University Medical Center

BACKGROUND

Glaucoma is a significant public health problem due to its substantial increase in the projected number of glaucoma cases. In Ethiopia, glaucoma accounts for 5.2% of irreversible blindness and is the fifth main cause of blindness. The main objective of this study was to modeling time to blindness of left and right eyes of glaucoma patients.

STUDY DESIGN

An institution-based retrospective cohort study.

METHODS

This study was conducted among 315 glaucoma patients admitted to the Ophthalmology Department of Jimma University Medical Center (JUMC), Southwest Ethiopia, from January 1, 2016, to August 30, 2020. Kaplan-Meier survival analysis and semiparametric and parametric copula models were applied to identify factors that affect time to the blindness in glaucoma patients and the dependence between time to the blindness of the left and right eyes, respectively. An Akaike information criterion (AIC) was used to select the best non-nested model.

RESULTS

In total, 211 (66.9%) out of 315 glaucoma patients were blind, whereas 104 (33.1%) patients were censored. The median time to the blindness of the left and right eyes was determined to be 12 months. The result suggested that the risk of the blindness in male patients was 1.005 (P = 0.01) times higher than that in female patients, and the risk of the blindness in patients who had early, moderate, and advanced glaucoma was estimated to be 0.582 (P = 0.002), 0.485 (P = 0.001) and 0.887 (P = 0.003) times less than that in the patients with absolute glaucoma, respectively.

CONCLUSIONS

Age, place of residence, gender, type of medication, diabetes disease, stage of glaucoma, duration of treatment, intraocular pressure (IOP), and cup-disk ratio were significantly associated with and affected by the time to the blindness of left and right eyes in glaucoma patients. Awareness should be given to the community to reduce the burden of glaucoma.

The Cost-Effectiveness of a Telemedicine Screening Program for Diabetic Retinopathy in New York City

Background

A telemedicine screening initiative was implemented by the Montefiore Health System to improve access to eyecare for a multi-ethnic, at-risk population of diabetic patients in a largely underserved urban community in the Bronx, New York. This retrospective, cross-sectional analysis evaluates the societal benefit and financial sustainability of this program by analyzing both cost and revenue generation based on current standard Medicare reimbursement rates.

Methods

Non-mydriatic fundus cameras were placed in collaboration with a vendor in eight outpatient primary care sites throughout the Montefiore Health Care System, and data was collected between June 2014 and July 2016. Fundus photos were electronically transmitted to a central reading center to be systematically reviewed and coded by faculty ophthalmologists, and patients were subsequently scheduled for ophthalmic evaluation based upon a predetermined treatment algorithm. A retrospective chart review of 2251 patients was performed utilizing our electronic medical record system (Epic Systems, Verona WI). Revenue was projected utilizing standard Medicare rates for our region while societal benefit was calculated using quality adjusted life years (QALY).

Results

Of the 2251 patient charts reviewed, 791 patients (35.1%) were seen by Montefiore ophthalmologists within a year of the original screening date. Estimated revenue generated by these visits was $276,800, with the majority from the treatment of retinal disease ($208,535), and the remainder from other ophthalmic conditions detected in the fundus photos ($68,265). There was a societal benefit of 14.66 quality adjusted life years (QALYs) with an estimated value of $35,471/QALY.

Conclusion

This telemedicine initiative was successful in identifying many patients with diabetic retinopathy and other ophthalmic conditions who may otherwise not have been formally evaluated. Our analysis demonstrates the program to generate a downstream revenue of nearly $280K with a cost benefit below <50% of the threshold of $100,000/QALY, and therefore cost-effective in marginalized communities.

Clinical Practice Management of Primary Open-Angle Glaucoma in the United States: An Analysis of Real-World Evidence

PURPOSE

To investigate clinical management of primary open-angle glaucoma (POAG) in the United States using real-world evidence and to examine healthcare resource utilization (HCRU), medication adherence/persistence, and procedure use.

DESIGN

A cross-sectional, retrospective analysis of Optum's de-identified Market Clarity Dataset (July 1, 2013-December 31, 2019).

PATIENTS AND METHODS

Patients ≥18 years with POAG diagnosis and continuous enrollment for 1-year pre- and post-index were eligible and categorized into four mutually exclusive cohorts: CH1, treated with antiglaucoma medication(s) only; CH2, underwent glaucoma procedure(s) only; CH3, treated with antiglaucoma medication(s) and underwent procedure(s); and CH4, received no treatment for POAG. Adherence and persistence with antiglaucoma medications, and disease-specific HCRU were analyzed. Pairwise two-sample comparisons and multivariate regressions were conducted.

RESULTS

Examined 232,572 eligible patients (CH1=60,895; CH2=4330; CH3=6027; CH4=161,320). Prostaglandin analogs were most prescribed antiglaucoma medications (CH1: 69.7%; CH3: 62.7%), of which latanoprost was most common (CH1: 51.3%; CH3: 46.1%). Disease-specific office visits occurred in 26.3%, 78.2%, 75.0%, 23.8%, and surgical services visits occurred in 3.8%, 36.3%, 42.5%, 3.3%, in CH1-CH4, respectively. Adherence was higher (medication possession ratio: 47.1% vs 39.4%; P<0.0001), and more patients remained persistent across 1-year post-index period in CH1 vs CH3 (25.4% vs 16.1%; P<0.0001). Positive predictors of medication persistence included being female, ≥55 years, and history of dyslipidemia or thyroid disease (all P≤0.0003).

CONCLUSION

Overall, 70% POAG patients might not have received antiglaucoma treatment. Since POAG is a slowly progressive blinding disease, the lack of antiglaucoma treatment and suboptimal adherence/persistence with medications are of major concerns. Targeted screening and educational approaches are needed to improve POAG management.

The connection of polymorphism and diurnal changes of the biological clock gene expression with the risk of progression of primary open-angle glaucoma

The purpose of this work is to study the connection betweengenetic factors (polymorphism and expression of key genes of the biological clock (KGBC), key genes controlled by KGBC, melatonin receptors) and the diurnal oscillation of melatonin in patients with stable and progressing primary open-angle glaucoma. Materials and methods. The study involved 115 patients aged 53–86 (averagely, 68.8 ± 7.9 years) with stable and progressive glaucoma. All patients underwent primary ophthalmological examination, tested for diurnal body temperature profile, intraocular pressure (IOP), melatonin (by the DLMO protocol) and were typed for key genes of the biological clock using the real-time polymerase chain reaction. We studied the sleep phase shift to later hours in carriers of the G-allele of the melatonin receptor gene during the progression of glaucoma. Results. The study of the clinical and genotypic features of the POAG course revealed phasal shifts of the circadian rhythms of body temperature, IOP, salivary melatonin levels and sleep phases which contributed to the progression of glaucomatous optic neuropathy. Certain polymorphic variants of genes contribute to individual frequent manifestations of desynchronosis. The clock rs1801260 and MTNR1B rs10830963 gene polymorphism was found to be related to disturbances in melatonin production and sleep phase. Conclusion. Complex manifestations of circadian desynchronization accompanying the progressive course of glaucoma are the late phase of rhythms and a decrease in sleep duration, body temperature, salivary melatonin and IOP, internal desynchronization between IOP and body temperature, IOP and sleep, evening dyslipidemia. The revealed patterns open up prospects for future studies of the relationship between polymorphism and daily changes of the expression of key genes in the biological clock with the risk of progression of primary open angle glaucoma.

Differences in clinical presentation of primary open-angle glaucoma between African and European populations

Purpose

Primary open‐angle glaucoma (POAG) has been reported to occur more frequently in Africans, and to follow a more severe course compared to Europeans. We aimed to describe characteristics of POAG presentation and treatment across three ethnic groups from Africa and one from Europe.

Methods

We ascertained 151 POAG patients from South African Coloured (SAC) and 94 South African Black (SAB) ethnicity from a university hospital in South Africa. In Tanzania, 310 patients were recruited from a university hospital and a referral hospital. In the Netherlands, 241 patients of European ancestry were included. All patients were over 35 years old and had undergone an extensive ophthalmic examination. Patients were diagnosed according to the ISGEO criteria. A biogeographic ancestry analysis was performed to estimate the proportion of genetic African ancestry (GAA).

Results

The biogeographic ancestry analysis showed that the median proportion of GAA was 97.6% in Tanzanian, 100% in SAB, 34.2% in SAC and 1.5% in Dutch participants. Clinical characteristics at presentation for Tanzanians, SAB, SAC and Dutch participants, respectively: mean age: 63, 57, 66, 70 years (p < 0.001); visual acuity in the worse eye: 1.78, 1.78, 0.3, 0.3 LogMAR (p < 0.001); maximum intraocular pressure of both eyes: 36, 34, 29, 29 mmHg (p_anova < 0.001); maximum vertical cup to disc ratio (VCDR) of both eyes: 0.90, 0.90, 0.84, 0.83 (p < 0.001); mean central corneal thickness: 506, 487, 511, 528 μm (p < 0.001). Fourteen percent of Tanzanian patients presented with blindness (<3/60 Snellen) in the better eye in contrast to only 1% in the Dutch.

Conclusion

In this multi‐ethnic comparative study, Sub‐Saharan Africans present at a younger age with lower visual acuity, higher IOP, larger VCDR, than SAC and Dutch participants. This indicates the more progressive and destructive course in Sub‐Saharan Africans.

Determinants of Intraocular Pressure and Time to Blindness for Glaucoma Patients at Felege Hiwot Referral Hospital, Bahir Bar, Ethiopia: A Comparison of Separate and Joint Models

Background:

Due to the substantial increase in the number of glaucoma cases within the next several decades, glaucoma is a significant public health issue. The main objective of this study was to investigate the determinant factors of intraocular pressure and time to blindness of glaucoma patients under treatment at Felege Hiwot Referral Hospital, Bahir Dar, Ethiopia.

Methods:

A retrospective study design was conducted on 328 randomly selected glaucoma patients using simple random sampling based on the identification number of patients in an ophthalmology clinic at the hospital under the follow-up period from January 2014 to December 2018. A linear mixed effects model for intraocular pressure data, a semi-parametric survival model for the time-to-blindness data and joint modeling of the 2 responses were used for data analysis. However, the primary outcome was survival time of glaucoma patients.

Results:

The comparison of joint and separate models revealed that joint model was more adequate and efficient inferences because of its smaller standard errors in parameter estimations. This was also approved using AIC, BIC, and based on a significant likelihood ratio test as well. The estimated association parameter (α) in the joint model was .0160 and statistically significant (P-value = .0349). This indicated that there was strong evidence for positive association between the effects of intraocular pressure and the risk of blindness. The result indicated that the higher value of intraocular pressure was associated with the higher risk of blindness. Age, hypertension, type of medication, cup-disk ratio significantly affects both average intraocular pressure and survival time of glaucoma patients (P-value < .05).

Conclusion:

The predictors; age, hypertension, type of medication, and cup-disk ratio were significantly associated with the 2 responses of glaucoma patients. Health professionals give more attention to patients who have blood pressure and cup-disk ratio greater than 0.7 during the follow-up time to reduce the risk of blindness of glaucoma patients.

Comparison of Compass Suprathreshold Screening Strategies

Screening programs may be useful to reduce the rate of undetected glaucoma. Compass (CMP, CenterVue, Padova, Italy) Standard Suprathreshold strategy (SST) analyses the visual function at 52 retinal locations. A new Quick Suprathreshold strategy (QST) reduces the number of tested locations to 24. With both tests, the CMP also provides an image of the central retina and a detail of the optic nerve head. The aim of this paper is to measure the performances of SST and QST compared with clinical diagnosis. 63 consecutive healthy subjects and 60 consecutive patients with perimetric defects from glaucoma in both eyes were recruited. They received one test per eye (SST or QST in randomized order); results were classified into normal, suspect and abnormal according to a global index provided in the report and called SupraThreshold Response (STR). Agreement between clinical diagnosis and test output were calculated, and test time was also measured. The agreement with the clinical diagnosis was 95.7% for SST and 95.1% for QST. When two suspect tests were excluded, agreement for QST increased to 96.7%. Test duration was 164 ± 82 s for SST and 71 ± 41 s for QST (p < 0.0001). Such a difference was similar in both glaucoma patients (respectively 231 ± 65 s vs. 105 ± 33 s, p < 0.0001) and normal subjects (98 ± 17 and 39 ± 9 s, p < 0.0001). In conclusion, SST and QST showed similar, high agreement with clinical judgement. Morphological analysis is potentially helpful in further improving the clinical usefulness of suprathreshold tests. QST is characterized by a strong time saving compared with SST.

Determinants of Intraocular Pressure (IOP) of Glaucoma Patients at Felege Hiwot Referral Hospital, Bahir Dar, Ethiopia

Background. Glaucoma is a leading cause of irreversible blindness in the world associated with characteristic damage to the optic nerve and patterns of visual field loss due to retinal ganglion cell degeneration. The main objective of this study was to investigate determinants for the variation of intraocular pressure of glaucoma patients under treatment at Felege Hiwot Referral Hospital, Bahir Dar, Ethiopia. Methods. A retrospective cohort study design was conducted on 328 randomly selected glaucoma patients in the ophthalmology clinic at the hospital under the follow-up period from January 2014 to December 2018. Glaucoma patients who have two and more than two visits in the study period were included in the study, but patients who are attending medications less than two visits were excluded from the study. A linear mixed-effects model for intraocular pressure change was used for data analysis. Result. The estimated coefficient of fixed effect intercept was 25.1829, which indicates that the average IOP of the patients was 25.1829 mmHg at baseline time by excluding all covariates in the model ( $p$ value <0.0001), age ( $\beta$ =0.07, 95%CI 0.03, 0.11), urban residence ( $\beta$  = −1.60, 95%CI −2.84, −0.36), family history of glaucoma ( $\beta$  = 4.90, 95%CI 3.38–6.43), timolol and pilocarpine medication ( $\beta$  = −2.02, 95%CI −4.01, −0.03), cup-disk ratio >0.7 ( $\beta$  = 2.60, 95% CI 1.24–3.96), and follow-up time ( $\beta$  = −0.34, 95%CI −0.47, −0.21) were significantly associated with intraocular pressure of glaucoma patients. Conclusion. The predictor age, residence, family history of glaucoma, type of medication, cup-disk ratio, and follow-up time were significantly associated with the intraocular pressure of glaucoma patients. Therefore, healthcare providers give more attention and prioritize those identified factors and give frequent counseling about reducing intraocular pressure of glaucoma patients.

Health care cost and benefits of artificial intelligence-assisted population-based glaucoma screening for the elderly in remote areas of China: a cost-offset analysis

Background

Population-based screening was essential for glaucoma management. Although various studies have investigated the cost-effectiveness of glaucoma screening, policymakers facing with uncontrollably growing total health expenses were deeply concerned about the potential financial consequences of glaucoma screening. This present study was aimed to explore the impact of glaucoma screening with artificial intelligence (AI) automated diagnosis from a budgetary standpoint in Changjiang county, China.

Methods

A Markov model based on health care system’s perspective was adapted from previously published studies to predict disease progression and healthcare costs. A cohort of 19,395 individuals aged 65 and above were simulated over a 15-year timeframe. Fur illustrative purpose, we only considered primary angle-closure glaucoma (PACG) in this study. Prevalence, disease progression risks between stages, compliance rates were obtained from publish studies. We did a meta-analysis to estimate diagnostic performance of AI automated diagnosis system from fundus image. Screening costs were provided by the Changjiang screening programme, whereas treatment costs were derived from electronic medical records from two county hospitals. Main outcomes included the number of PACG patients and health care costs. Cost-offset analysis was employed to compare projected health outcomes and medical care costs under the screening with what they would have been without screening. One-way sensitivity analysis was conducted to quantify uncertainties around model results.

Results

Among people aged 65 and above in Changjiang county, it was predicted that there were 1940 PACG patients under the AI-assisted screening scenario, compared with 2104 patients without screening in 15 years’ time. Specifically, the screening would reduce patients with primary angle closure suspect by 7.7%, primary angle closure by 8.8%, PACG by 16.7%, and visual blindness by 33.3%. Due to early diagnosis and treatment under the screening, healthcare costs surged dramatically to $107,761.4 dollar in the first year and then were constantly declining over time, while without screening costs grew from $14,759.8 in the second year until peaking at $17,900.9 in the 9th year. However, cost-offset analysis revealed that additional healthcare costs resulted from the screening could not be offset by decreased disease progression. The 5-, 10-, and 15-year accumulated incremental costs of screening versus no screening were estimated to be $396,362.8, $424,907.9, and $434,903.2, respectively. As a result, the incremental cost per PACG of any stages prevented was $1464.3.

Conclusions

This study represented the first attempt to address decision-maker’s budgetary concerns when adopting glaucoma screening by developing a Markov prediction model to project health outcomes and costs. Population screening combined with AI automated diagnosis for PACG in China were able to reduce disease progression risks. However, the excess costs of screening could never be offset by reduction in disease progression. Further studies examining the cost-effectiveness or cost-utility of AI-assisted glaucoma screening were needed.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-11097-w.

EffUnet-SpaGen: An Efficient and Spatial Generative Approach to Glaucoma Detection

Current research in automated disease detection focuses on making algorithms “slimmer” reducing the need for large training datasets and accelerating recalibration for new data while achieving high accuracy. The development of slimmer models has become a hot research topic in medical imaging. In this work, we develop a two-phase model for glaucoma detection, identifying and exploiting a redundancy in fundus image data relating particularly to the geometry. We propose a novel algorithm for the cup and disc segmentation “EffUnet” with an efficient convolution block and combine this with an extended spatial generative approach for geometry modelling and classification, termed “SpaGen” We demonstrate the high accuracy achievable by EffUnet in detecting the optic disc and cup boundaries and show how our algorithm can be quickly trained with new data by recalibrating the EffUnet layer only. Our resulting glaucoma detection algorithm, “EffUnet-SpaGen”, is optimized to significantly reduce the computational burden while at the same time surpassing the current state-of-art in glaucoma detection algorithms with AUROC 0.997 and 0.969 in the benchmark online datasets ORIGA and DRISHTI, respectively. Our algorithm also allows deformed areas of the optic rim to be displayed and investigated, providing explainability, which is crucial to successful adoption and implementation in clinical settings.

Advances in the discovery of novel agents for the treatment of glaucoma

INTRODUCTION

Glaucoma, a neuropathy characterized by increased intraocular pressure (IOP), is the major cause of blindness worldwide and its treatment aims at reducing IOP.

AREAS COVERED

The authors review the design of the main classes of anti-glaucoma agents. Drugs which interfere with the aqueous humor secretion (adrenergic agonists/antagonists, carbonic anhydrase inhibitors) and with its outflow, by means of both conventional and non-conventional pathways (prostaglandin (PG) analogs, rho kinase inhibitors, nitric oxide (NO) donors) as well as new agents (adenosine receptors modulators, melatonin - fatty acid amide hydrolase hybrids, tyrosine kinase activators, natriuretic peptide analogs) are considered.

EXPERT OPINION

The anti-glaucoma drug field has undergone several developments in recent years with the approval of at least three new drugs belonging to novel pharmacological classes, the rho kinase inhibitors ripasudil and netarsudil, and the PG-NO donor hybrid latanoprostene bunod. Eye drops with combinations of two different drugs are also available, allowing for effective IOP control, with once daily administration for some of them, which assures a better patient compliance and ease of administration. Overall, after more than a decade without new anti-glaucoma drugs, the last year afforded interesting new pharmacological opportunities for the management of this disease.

Using Social Media in Tourist Sentiment Analysis: A Case Study of Andalusia during the Covid-19 Pandemic

This paper explores the role of social media in tourist sentiment analysis. To do this, it describes previous studies that have carried out tourist sentiment analysis using social media data, before analyzing changes in tourists’ sentiments and behaviors during the COVID-19 pandemic. In the case study, which focuses on Andalusia, the changes experienced by the tourism sector in the southern Spanish region as a result of the COVID-19 pandemic are assessed using the Andalusian Tourism Situation Survey (ECTA). This information is then compared with data obtained from a sentiment analysis based on the social network Twitter. On the basis of this comparative analysis, the paper concludes that it is possible to identify and classify tourists’ perceptions using sentiment analysis on a mass scale with the help of statistical software (RStudio and Knime). The sentiment analysis using Twitter data correlates with and is supplemented by information from the ECTA survey, with both analyses showing that tourists placed greater value on safety and preferred to travel individually to nearby, less crowded destinations since the pandemic began. Of the two analytical tools, sentiment analysis can be carried out on social media on a continuous basis and offers cost savings.

BrdU Positive Cells Induced in a Genetic Mouse Model of Glaucoma

Previous studies have shown that eye drop application of the selective α7 nicotinic acetylcholine receptor agonist, PNU-282987, induces neurogenesis of RGCs in adult wild-type rodents. This study was designed to test the hypothesis that PNU-282987 reverses the loss of RGCs associated with glaucoma. A DBA/2J mouse model that auto-induces a glaucoma-like condition in adulthood was used for these studies. Short-term effects using PNU-282987 and BrdU eye drop treatments were examined, as well as the effects of early treatment and the effects in a chronic early treatment group in DBA/2J mice aged 3, 6 and 10 months. With and without treatment, retinas were removed, fixed, immunostained and RGC counts were assessed. IOP measurements were obtained weekly using a Tonolab tonometer. Results showed an average typical loss of BrdU positive RGCs by 29% by 10 months of age in this DBA/2J colony corresponding with a significant increase in IOP. However, the two-week short term application of PNU-282987 and BrdU induced a significant 21% increase in RGCs for DBA/2J mice at all ages. Chronic early PNU-282987 treatment produced a similarly significant increase in RGCs, while acute early treatment had no effect on RGC numbers. IOP measurements were not affected with PNU-282987 treatment. These studies demonstrated that 2-week treatment with PNU-282987, as well as chronic long-term treatment, induced a significant increase in the number of RGCs in the DBA/2J retina, counteracting the effects of the DBA/2J genetic glaucoma-like condition. These results suggest a potential future treatment of degenerative retinal diseases with PNU-282987.

Uptake, Persistence, and Performance of Weekly Home Monitoring of Visual Field in a Large Cohort of Patients With Glaucoma

PURPOSE

This study examines the short-term uptake, compliance, and performance of a tablet device used for home monitoring of visual field (VF-Home) by glaucoma patients.

DESIGN

Single-center, observational, longitudinal, compliance study.

METHODS

Participants who were glaucoma suspects or had stable glaucoma in at least one eye were recruited during a regular clinic review. Baseline in-clinic visual field (VF) was recorded with the Humphrey Field Analyser (HFA, SITA standard) and repeated at 6 months. Participants were tasked with performing 6 VF examinations from home, at weekly intervals, using a loaned iPad tablet. Uptake was defined as returning at least 1 test from home. Reliability and global indices from VF-Home were compared to in-clinic outcomes. Data are shown as either mean ± [standard deviation] or median [quartile 1-3 range], and group comparisons were achieved with bootstrap.

RESULTS

We recruited 186 eyes of 101 participants. VF-Home uptake was excellent, with 88% of participants successfully completing ≥1 home examination and 69% completing all 6 examinations. The median duration between tests was 7.0 [7.0-8.0] days. Barriers to uptake and compliance involved information technology (IT) logistical reasons, lack of motivation, or competing life demands. VF-Home gave greater fixation loss but a similar level of False Positives (FP) as the HFA. A high correlation was found for the mean defect between in-clinic and at-home outcomes (R = 0.85).

CONCLUSIONS

VF-Home can return a high level of short-term compliance and results comparable to those found by in-clinic testing. IT logistical reasons and lack of motivation are barriers to uptake and compliance.

The Role of Neuroinflammation in Glaucoma: An Update on Molecular Mechanisms and New Therapeutic Options

Glaucoma is a multifactorial optic neuropathy characterized by the continuous loss of retinal ganglion cells, leading to progressive and irreversible visual impairment. In this minireview, we report the results of the most recent experimental studies concerning cells, molecular mechanisms, genes, and microbiome involved in neuroinflammation processes correlated to glaucoma neurodegeneration. The identification of cellular mechanisms and molecular pathways related to retinal ganglion cell death is the first step toward the discovery of new therapeutic strategies. Recent experimental studies identified the following possible targets: adenosine A_2A receptor, sterile alpha and TIR motif containing 1 (neurofilament light chain), toll-like receptors (TLRs) 2 and 4, phosphodiesterase type 4 (PDE4), and FasL-Fas signaling (in particular ONL1204, a small peptide antagonist of Fas receptors), and therapies directed against them. The continuous progress in knowledge provides interesting data, although the total lack of human studies remains an important limitation. Further research is required to better define the role of neuroinflammation in the neurodegeneration processes that occur in glaucomatous disease and to discover neuroprotective treatments amenable to clinical trials. The hereinafter reviewed studies are reported and evaluated according to their translational relevance.

Rates of Glaucomatous Structural and Functional Change From a Large Clinical Population: The Duke Glaucoma Registry Study

PURPOSE

To investigate rates of structural and functional change in a large clinical population of glaucoma and glaucoma suspect patients.

DESIGN

Retrospective cohort.

METHODS

Twenty-nine thousand five hundred forty-eight spectral-domain optical coherence tomography (OCT) and 19,812 standard automated perimetry (SAP) tests from 6138 eyes of 3669 patients with ≥6 months of follow-up, 2 good quality spectral-domain OCT peripapillary retinal nerve fiber layer scans, and 2 reliable SAP tests were included. Data were extracted from the Duke Glaucoma Registry, a large database of electronic health records of patients from the Duke Eye Center and satellite clinics. Rates of change for the 2 metrics were obtained using linear mixed models, categorized according to pre-established cutoffs, and analyzed according to the severity of the disease.

RESULTS

Average rates of change were -0.73 ± 0.80 μm per year for global retinal nerve fiber layer thickness and -0.09 ± 0.36 dB per year for SAP mean deviation. More than one quarter (26.6%) of eyes were classified as having at least a moderate rate of change by spectral-domain OCT vs 9.1% by SAP (P < .001). In eyes with severe disease, 31.6% were classified as progressing at moderate or faster rates by SAP vs 26.5% by spectral-domain OCT (P = .055). Most eyes classified as fast by spectral-domain OCT were classified as slow by SAP and vice versa.

CONCLUSION

Although most patients under routine care had slow rates of progression, a substantial proportion had rates that could potentially result in major losses if sustained over time. Both structural and functional tests should be used to monitor glaucoma, and spectral-domain OCT still has a relevant role in detecting fast progressors in advanced disease.

Cannabinoids in Glaucoma Patients: The Never-Ending Story

Glaucoma is one of the principal causes of irreversible blindness worldwide. Yet, intraocular pressure (IOP) is the main modifiable risk factor for disease progression. In the never-ending challenge to develop new and effective drugs, several molecules have been tested as anti-glaucoma agents thanks to their pressure-lowering capabilities. Among these molecules, the cannabinoids have been investigated as possible anti-glaucoma drugs since the early 1970s. Cannabinoids are a large class of chemical compounds that exploit their effects by interaction with cannabinoid receptors 1 and 2. These receptors are widely expressed in the human retina where they may influence important functions such as photo-transduction, amacrine cell network maintenance, and IOP regulation. Therefore, in past years several studies have been conducted in order to assess the IOP lowering effects of cannabinoids. PRISMA guidelines have been used to perform a literature search on Pubmed and Scopus aiming to investigate the mechanism of IOP lowering effects and the potential benefits of orally administered, inhaled, topical, and intravenous cannabinoids in the treatment of glaucoma patients.

Cost-effectiveness and budget impact analysis of a patient visit support system for blindness reduction in Japanese patients with glaucoma

AIM

To evaluate the cost-effectiveness (CE) and budget impact (BI) of introducing a patient visit support system (ACT Pack) along with standard of care (SoC), in glaucoma treatment in Japan.

METHODS

A Markov model was designed to estimate the CE and BI of introducing the support system from Japanese payer and governmental perspective, respectively. Inputted data for CE and BI analysis were referred from published literature and based on medical specialists' inputs. Base case scenario for CE considered the support system cost of 30,000 yen per patient per year and a time horizon of 45 years. BI analysis compared the financial impact due to introduction of support system with SoC compared to SoC alone scenario on Japanese healthcare system with a time horizon of 20 years.

RESULTS

The base case of CE analysis showed the incremental cost per quality-adjusted life years (QALYs) gained with the support system was 3,241,729 yen/QALY (29,470 USD/QALY). The sensitivity analysis showed that the probability of this support system being cost-effective at a threshold of 5 million yen/QALY (45,455 USD/QALY) was 53.26%. Blindness reduction after introduction of this support system was 8.68%. The BI analysis showed that the introduction of support system will lead to a cumulative cost savings of 1,132 billion yen (10 billion US dollars) for Japanese healthcare system over 20 years of time horizon.

LIMITATION

Due to paucity of similar comparative studies, some assumptions were made based on medical specialists' inputs. Death status was not considered in the analysis.

CONCLUSION

Introduction of this support system with SoC is cost-effective and will lead to blindness reduction in Japanese patients with glaucoma. Over a 20 year period, it will lead to an overall cost savings of 1,132 billion yen (10 billion US dollars) for the Japanese healthcare system.

Point-wise correlations between 10-2 Humphrey visual field and OCT data in open angle glaucoma

PURPOSE

Optical Coherence Tomography (OCT) is a powerful instrument for helping clinicians detect and monitor glaucoma. The aim of this study was to provide a detailed mapping of the relationships between visual field (VF) sensitivities and measures of retinal structure provided by a commercial Spectral Domain (SD)-OCT system (RTvue-100 Optovue).

METHODS

Sixty-three eyes of open angle glaucoma patients (17 males, 16 females, and mean age 71 ± 7.5 years) were included in this retrospective, observational clinical study. Thickness values for superior and inferior retina, as well as average values, were recorded for the full retina, the outer retina, the ganglion cell complex, and the peripapillary retinal nerve fiber layer (RNFL). RNFL thickness was further evaluated along eight separate sectors (temporal lower, temporal upper, superior temporal, superior nasal, nasal upper, nasal lower, inferior nasal, and inferior temporal). Point-wise correlations were then computed between each of these OCT measures and the visual sensitivities at all VF locations assessed via Humphrey 10-2 and 24-2 perimetry. Lastly, OCT data were fit to VF data to predict glaucoma stage.

RESULTS

The relationship between retinal thickness and visual sensitivities reflects the known topography of the retina. Spatial correlation patterns between visual sensitivities and RNFL thickness along different sectors broadly agree with previously hypothesized structure-function maps, yet suggest that structure-function maps still require more precise characterizations. Given these relationships, we find that OCT data can predict glaucoma stage.

CONCLUSION

Ganglion cell complex and RNFL thickness measurements are highlighted as the most promising candidate metrics for glaucoma detection and monitoring.

Visual impairment in pseudoexfoliation from four tertiary centres in India

Purpose

To analyse the disease burden of pseudoexfoliation (PXF) disease stages from East and South India.

Design

Prospective hospital based study of patients seen at 4 tertiary centres.

Subjects, participants, and/or controls

Consecutive old and new patients of pseudoexfoliation with normal intraocular pressure (IOP), raised IOP (PXF with Ocular hypertension, OHT) and irreversible disc/field changes (pseudoexfoliation glaucoma, PXG) seen from April 2016-March 2017 at a tertiary centre in Odisha, East India and 3 centres in Andhra Pradesh and Telangana, South India, recruited into the prospective study were screened for baseline characteristics.

Methods

The clinical and demographic details including visual acuity, laterality, intraocular pressure (IOP) with details of medical/surgical therapy at presentation were collected from the hospital database at all 4 centres.

Intervention or exposure

The World Health Organization WHO visual criteria were used for defining visual impairment/absolute blindness in different disease stages.

Outcome measures

The visual impairment/blindness rates with comorbidities in the anterior/posterior segment in PXF, OHT and PXG at baseline were compared and the influence of age, IOP fluctuations and laterality was analysed using multivariate logistic regression.

Results

Of 6284 PXF eyes (of 3142 patients) included from all centres, OHT and PXG was seen in 2.1% and 29% respectively which included 3676 (>50%) bilateral PXF eyes. Reversible visual impairment rates caused by PXF associated co-morbidities in PXF and OHT were 33% and 26% respectively with cataract being the major cause (67% in PXF and 74% in OHT). Irreversible blindness rate was higher in bilateral PXG eyes (30.5%) compared to bilateral PXF (23.2%) or bilateral OHT (21.6%) with overall absolute blindness rates of 28.2% at presentation. Older age (p<0.001), bilaterality and higher baseline IOP were significantly associated with higher rates of blindness in PXF eyes.

Conclusion and relevance

Pseudoexfoliation is associated with ≥30% visual impairment across all stages and 28% absolute blindness rate which is a huge hidden burden of glaucoma. Adequate disease staging and assessment of comorbidities is required for accurate prognostication at baseline and reducing avoidable pseudoexfoliation blindness.

Progression to blindness in 20 years among patients with glaucomatous visual field loss in a tertiary hospital in the Philippines

Objective

To determine visual field (VF) rates of change among patients with glaucomatous VF loss and proportion of those becoming blind based on residual life expectancy and factors associated with fast progression.

Methods and analysis

This was a retrospective study of the VFs of patients with glaucomatous VF defects in at least one eye. Baseline and final VFs were reviewed. Rates of VF change (decibels (dB)/year) for each eye, together with the residual life expectancy based on age and sex, were used to predict mean deviation/defect (MD) at the end of expected lifetime. Blindness was defined if computed MD was 22 dB (Octopus) or −22 dB (Humphrey) or worse in the better eye. Factors associated with fast progression (>1 dB/year for Octopus or <−1 dB/year for Humphrey) and blindness were determined.

Results

There were 1016 eyes of 583 patients eligible. There was decline in VF MD/year in 613/1016 (60.3%), 95% CI (57.3% to 63.3%) of eyes; however, only 98/1016 (9.7%), 95% CI (7.9% to 11.5%) of eyes showed fast progression. Among patients with bilateral VFs, 43/433 (9.9%), 95% CI (7.1 to 12.8) of eyes were predicted to progress to blindness. In multivariate analysis, factors associated with fast progression were baseline MD (p<0.001) and male sex (p=0.041). Factors associated with blindness were age <60 years (p=0.003), baseline MD (p=0.022), bilateral glaucomatous VF defects (p=<0.001) and fast progression (p<0.001).

Conclusion

Patients reaching blindness in a routine clinical setting was 10%. Because of association of age and baseline MD on blindness, early disease detection is important. VF progression rates and residual life expectancy must be incorporated in glaucoma care.

Adreno-melatonin receptor complexes control ion homeostasis and intraocular pressure - their disruption contributes to hypertensive glaucoma

BACKGROUND AND PURPOSE

Often, glaucoma presents with elevated eye hydrostatic pressure, which is regulated by endogenous melatonin. Phenylephrine increases cytoplasmic [Ca²⁺ ], via α₁ -adrenoceptor activation, that is detrimental in glaucoma. The aims of this study were (a) to elucidate the role of melatonin receptors in humour production and intraocular pressure (IOP) maintenance and (b) to identify glaucoma-relevant melatonin-adrenoceptor interactions.

EXPERIMENTAL APPROACH

Biophysical and proximity ligation assays were performed to identify interactions in heterologous expression systems, in cell lines and in human eyes. G_s /G_i /G_q signalling was investigated in these systems and in cells producing aqueous humour. IOP was determined in a mice model of glaucoma. Retinography and topically pharmacological treatment were performed in control and in glaucomatous mice.

KEY RESULTS

α₁ -adreno- and melatonin receptors form functional complexes in which the C-terminal tail of the adrenoceptor plays a role. Remarkably, activation of α₁ -adrenoceptors in these complexes did not lead to cytosolic Ca²⁺ increases, suggesting G_s instead of G_q coupling is involved. The number of these complexes significantly decreased in models of glaucoma and, importantly, in human samples from glaucoma patients. This has led to hypothesize that melatonin, a hypotensive agent, plus blockade of α₁ -adrenoceptors could normalize pressure in glaucoma. Remarkably, co-instillation of melatonin and prazosin, an α₁ -adrenoceptor antagonist, resulted in long-term decreases in IOP in a well-established animal model of glaucoma.

CONCLUSIONS AND IMPLICATIONS

The findings are instrumental to understand the physiological function of melatonin in the eye and its potential to address eye pathologies by targeting melatonin receptors and their complexes.

Stimulation of Retinal Pigment Epithelium With an α7 nAChR Agonist Leads to Müller Glia Dependent Neurogenesis in the Adult Mammalian Retina

Purpose

The adult mammalian retina is typically incapable of regeneration when damaged by disease or trauma. Restoration of function would require generation of new adult neurons, something that until recently, mammals were thought to be incapable of doing. However, previous studies from this laboratory have shown that the α7 nicotinic acetylcholine receptor (α7 nAChR) agonist, PNU-282987, induces cell cycle reentry of Müller glia and generation of mature retinal neurons in adult rats, in the absence of detectible injury. This study analyzes how PNU-282987 treatment in RPE leads to robust BrdU incorporation in Müller glia in adult mice and leads to generation of Müller-derived retinal progenitors and neuronal differentiation.

Methods

Retinal BrdU incorporation was examined after eye drop application of PNU-282987 in adult wild-type and transgenic mice that contain tamoxifen-inducible tdTomato Müller glia, or after intraocular injection of conditioned medium from PNU-282987–treated cultured RPE cells.

Results

PNU-282987 induced robust incorporation of BrdU in all layers of the adult mouse retina. The α7 nAChR agonist was found to stimulate cell cycle reentry of Müller glia and their generation of new retinal progenitors indirectly, via the RPE, in an α7 nAChR-dependent fashion.

Conclusions

The results from this study point to RPE as a contributor to Müller glial neurogenic responses. The manipulation of the RPE to stimulate retinal neurogenesis offers a new direction for developing novel and potentially transformative treatments to reverse the loss of neurons associated with neurodegenerative disease, traumatic injury, or aging.

Precision medicine to prevent glaucoma-related blindness

PURPOSE OF REVIEW

Approximately 10% of patients become blind despite using evidence-based guidelines developed from clinical trials and epidemiology studies. Our purpose is to review opportunities to decrease glaucoma-related blindness using the emerging principles of precision medicine.

RECENT FINDINGS

The current review focuses on three topics: first, candidate biomarkers for angle-based surgeries, second, head-mounted display (HMD) technology for vision and testing, and third, glaucoma risk alleles discovered by genome-wide association studies. First, in angle-based surgeries, tracers injected into the anterior chamber or Schlemm's canal have allowed visualization of aqueous veins. We describe an innovative use of optical coherence tomography angiography to visualize aqueous veins in a case with 6-year successful outcome following catheter-based trabeculotomy. Second, HMD technology can augment perceived vision and can be used for perimetry testing. Third, developing genetic risk scores that characterize patients who are at highest risk for blindness is a priority. Such biomarker risk scores will integrate genome-wide association study-based risk alleles for glaucoma along with well known demographic and clinical risk factors.

SUMMARY

As we gain more knowledge, precision medicine will enable clinicians to decrease glaucoma-related blindness by providing more timely interventions to those patients who are at highest risk for progression to blindness. VIDEO ABSTRACT: http://links.lww.com/COOP/A29.

Twenty-year outcomes in patients with newly diagnosed glaucoma: mortality and visual function

Background/aims

To determine the mortality within 20 years of diagnosis of chronic open-angle glaucoma (COAG) and visual acuity and visual field progression of a cohort followed for 20 years.

Methods

Twenty years following the diagnosis of COAG in 68 of 436 (16%) patients seen in a glaucoma case-finding clinic, visual and mortality outcomes were audited from medical records. Causes of death were obtained from general practitioner records and death certificates. Probability of death was calculated using a Kaplan-Meier survival curve. The visual field of each eye of survivors was graded using a nine-stage severity scale. Visual outcome was analysed at the 20-year follow-up visit.

Results

From 68, 14 (21%) were lost to follow-up. In the remaining 54, 20 (37%) were alive 20 years after diagnosis. Of 63% who died, mean age of death was 84 years, most commonly due to vascular disease. Mean age at presentation of those who died was 73.7 years versus 63.2 years for survivors (P=0.001). The median time to death was 16 years. On visual field analysis, nearly half (48.9%) of eyes did not deteriorate, but 28.3% eyes deteriorated by more than two stages. Those who died had worse final visual acuity than survivors (P<0.001). Three who died were registered severely visually impaired mainly from macular disease, but no survivors were registered (P<0.001).

Conclusion

In this cohort, approximately two-thirds of patients with glaucoma died within 20 years of diagnosis. In most older patients with glaucoma, the overall goal of preventing visual handicap and blindness is achievable 20 years after diagnosis.

[Glaucoma in inpatient care in Germany in 2015]

AIM

Analysis of structural characteristics of inpatient treatment of glaucoma in clinical units run by affiliated physicians and those run by hospital physicians in Germany are described. The frequency and distribution of glaucoma diagnoses as the main and secondary diagnosis at different departments and glaucoma diagnoses, number of cases, surgeries and procedures and patient characteristics of the four glaucoma-specific diagnosis-related groups (DRG) are presented.

METHOD

Secondary data analysis using the G‑DRG browser from 2015/2016 provided by the German Institute for Remuneration Systems in Hospitals.

RESULTS

In 30% of the 156,524 cases glaucoma was classified as the main diagnosis, in 24% as secondary diagnosis in ophthalmological departments and 46% as secondary diagnosis in other departments. Primary open angle glaucoma was reported most frequently (40%), whilst non-ophthalmological departments mainly coded as "other" or "unspecified types of glaucoma". Glaucoma was coded in 20 DRGs as the main diagnosis and in all ophthalmic DRGs as secondary diagnosis. The number of cases and procedures differed among the four glaucoma-specific DRGs (C06Z, C07A, C07B, C64Z), the diagnostic spectrum, however, was similar. Patients were mainly women, older and with few comorbidities or complications. The C64Z was mainly characterized by cases with "suspected glaucoma" and only conservative procedures. Only 6% of the glaucoma patients were treated in clinical units run by affiliated physicians. In contrast to units run by hospital physicians surgical DRGs and operations prevailed but the diagnostic spectrum and patient characteristics were not different.

DISCUSSION AND CONCLUSION

With 20% of the main diagnoses, glaucoma was highly relevant for inpatient ophthalmological care. Glaucoma as a secondary diagnosis was also common in other medical specialties, though no diagnostic differentiation was made here. Patients with glaucoma are mainly treated in clinical units run by hospital physicians. Nevertheless, patients of affiliated physicians showed the same characteristics.

Identifying risk factors for blindness from primary open-angle glaucoma by race: a case-control study

Purpose

To examine the factors associated with blindness from primary open-angle glaucoma (POAG) among black and white patients at our institution.

Patients and methods

For this retrospective, case-control study, patients legally blind from POAG ("cases") were matched on age, race, and gender with non-blind POAG patients ("controls"). Thirty-seven black case-control pairs and 19 white case-control pairs were included in this study. Clinical variables were compared at initial presentation and over the course of follow-up.

Results

Black case-control pairs and white case-control pairs had similar characteristics at presentation, including cup-to-disc ratio and number of glaucoma medications. However, over the course of follow-up, black cases underwent significantly more glaucoma surgeries than matched controls (2.4 versus 1.2, p=0.001), whereas white cases and controls had no significant difference in glaucoma operations (0.9 versus 0.6, p=0.139). Our analysis found that glaucoma surgery is associated with blindness in black patients (odds ratio [OR] 1.6, 95% CI 1.1-2.2) but not in white patients (OR 1.5, 95% CI 0.7-3.2).

Conclusion

Black and white case-control pairs with POAG shared similar risk factors for blindness at presentation. However, over the follow-up period, black cases required significantly more glaucoma surgeries compared to black controls, whereas there was no significant difference in surgery between white cases and controls. There was no difference in medication changes in either case-control set.

Impact of Natural Blind Spot Location on Perimetry

We study the spatial distribution of natural blind spot location (NBSL) and its impact on perimetry. Pattern deviation (PD) values of 11,449 reliable visual fields (VFs) that are defined as clinically unaffected based on summary indices were extracted from 11,449 glaucoma patients. We modeled NBSL distribution using a two-dimensional non-linear regression approach and correlated NBSL with spherical equivalent (SE). Additionally, we compared PD values of groups with longer and shorter distances than median, and larger and smaller angles than median between NBSL and fixation. Mean and standard deviation of horizontal and vertical NBSL were 14.33° ± 1.37° and −2.06° ± 1.27°, respectively. SE decreased with increasing NBSL (correlation: r = −0.14, p < 0.001). For NBSL distances longer than median distance (14.32°), average PD values decreased in the upper central (average difference for significant points (ADSP): −0.18 dB) and increased in the lower nasal VF region (ADSP: 0.14 dB). For angles in the direction of upper hemifield relative to the median angle (−8.13°), PD values decreased in lower nasal (ADSP: −0.11 dB) and increased in upper temporal VF areas (ADSP: 0.19 dB). In conclusion, we demonstrate that NBSL has a systematic effect on the spatial distribution of VF sensitivity.

Relationship Between Central Retinal Vessel Trunk Location and Visual Field Loss in Glaucoma

PURPOSE

To study the relationship between horizontal central retinal vessel trunk location (CRVTL) on glaucomatous optic discs and sector-specific visual field (VF) loss.

DESIGN

Retrospective cross-sectional study.

METHODS

CRVTL of 421 eyes from 421 patients was manually tracked on the horizontal optic disc axis on fundus images. Focal circumpapillary retinal nerve fiber layer thickness (cpRNFLT) measurements were extracted from optical coherence tomography (OCT). The relationship between focal visual field (VF) loss and CRVTL and focal cpRNFLT was studied by linear regression models. Furthermore, we related central VF loss to CRVTL and focal cpRNFLT separately for mild (VF mean deviation [MD] ≥-6 dB), moderate (-12 dB ≤ MD <-6 dB), and severe (MD <-12 dB) glaucoma.

RESULTS

CRVTL nasalization was significantly correlated only to central VF loss (Garway-Heath scheme [central 6 locations, C6]: correlation: r = -0.16, P < .001; macular vulnerability zone [central 2 locations, C2]: r = -0.14, P = .003; central 4 locations [C4]: r = -0.17, P < .001). While focal cpRNFLT at the sectors corresponding to C2 and C6 was significantly correlated to the respective VF sectors as well (C2: r = 0.15, P = .002; C6: r = 0.10, P = .03), multivariate models combining cpRNFLT and CRVTL substantially improved structure-function models compared with cpRNFLT alone (likelihood ratio tests, C2 and C6: P < .001). The correlations between CRVTL and central VF loss of C4 were -0.11 (P = .04), -0.39 (P = .01), and -0.63 (P = .002) for mild, moderate, and severe glaucoma, respectively.

CONCLUSIONS

CRVTL nasalization is significantly and exclusively correlated to central VF loss for all glaucoma severities independent of cpRNFLT, and thus might be a structural biomarker of central VF loss.

Evidence of BrdU-positive retinal neurons after application of an Alpha7 nicotinic acetylcholine receptor agonist

Irreversible vision loss due to disease or age is responsible for a reduced quality of life. The experiments in this study test the hypothesis that the α7 nicotinic acetylcholine receptor agonist, PNU-282987, leads to the generation of retinal neurons in an adult mammalian retina in the absence of retinal injury or exogenous growth factors. Using antibodies against BrdU, retinal ganglion cells, progenitor cells and Müller glia, the results of this study demonstrate that multiple types of retinal cells and neurons are generated after eye drop application of PNU-282987 in adult Long Evans rats in a dose-dependent manner. The results of this study provide evidence that progenitor cells, derived from Müller glia after treatment with PNU-282987, differentiate and migrate to the photoreceptor and retinal ganglion cell layers. If retinas were treated with the alpha7 nAChR antagonist, methyllycaconitine, before agonist treatment, BrdU-positive cells were significantly reduced. As adult mammalian neurons do not typically regenerate or proliferate, these results have implications for reversing vision loss due to neurodegenerative disease or the aging process to improve the quality of life for millions of patients.

Impact of Age and Myopia on the Rate of Visual Field Progression in Glaucoma Patients

Myopia is rapidly increasing in young populations and patients with glaucoma associated with myopia are reported to be young aged in East Asia. These young patients have a longer life expectancy, which increases their risk of end-of-life visual disabilities. There is a need to understand the clinical course of myopic glaucoma patients, which may be important for the care of these myopic populations. In this study, we evaluated the relationship between the age at presentation and the rate of glaucoma progression in the visual field (VF) according to the presence of myopia. The study was conducted as a prospective observational study including 179 patients with open-angle glaucoma who had undergone at least 5 VF examinations with a follow-up of at least 5 years. The progression rate of the mean deviation (MD) and the pattern standard deviation (PSD) are expressed as change in decibels (dB) per year. The slopes of the MD and PSD were calculated by linear regression analyses. Factors related to the slope of VF MD changes were analyzed with correlation and regression analyses. The slope of the linear fit line plotted against age at presentation and the rate of change in the VF MD was -0.026 (P < 0.001) in the myopic group and -0.008 (P = 0.167) in the nonmyopic group; the relationship was more prominent in the myopic group than the nonmyopic group. In the myopic group, age (β = -0.417; 95% confidence intervals (CI), -0.651 to -0.200; P = 0.050) and baseline untreated intraocular pressure (β = -0.179; 95% CI, -0.331 to -0.028; P = 0.022) were significantly related to the rate of change in the MD, which was only the presence of disc hemorrhage (β = -0.335; 95% CI, -0.568 to -0.018; P = 0.022) in the nonmyopic group. Age at presentation was significantly related to the rate of change in the VF in glaucomatous eyes with myopia compared to eyes without myopia. Older age was significantly related to the rate of change in the VF only in myopic glaucomatous eyes.