Screening for Open-Angle Glaucoma and Its Effect on Blindness

Global estimates on the number of people blind or visually impaired by glaucoma: A meta-analysis from 2000 to 2020

OBJECTIVES

To estimate global and regional trends from 2000 to 2020 of the number of persons visually impaired by glaucoma and their proportion of the total number of vision-impaired individuals.

METHODS

A systematic review and meta-analysis of published population studies and grey literature from 2000 to 2020 was carried out to estimate global and regional trends in number of people with vision loss due to glaucoma. Moderate or severe vision loss (MSVI) was defined as visual acuity of 6/60 or better but <6/18 (moderate) and visual acuity of 3/60 or better but <6/60 (severe vision loss). Blindness was defined as presenting visual acuity <3/60.

RESULTS

Globally, in 2020, 3.61 million people were blind and nearly 4.14 million were visually impaired by glaucoma. Glaucoma accounted for 8.39% (95% uncertainty intervals [UIs]: 6.54, 10.29) of all blindness and 1.41% (95% UI: 1.10, 1.75) of all MSVI. Regionally, the highest proportion of blindness relating to glaucoma was found in high-income countries (26.12% [95% UI: 20.72, 32.09]), while the region with the highest age-standardized prevalence of glaucoma-related blindness and MSVI was Sub-Saharan Africa. Between 2000 and 2020, global age-standardized prevalence of glaucoma-related blindness among adults ≥50 years decreased by 26.06% among males (95% UI: 25.87, 26.24), and by 21.75% among females (95% UI: 21.54, 21.96), while MSVI due to glaucoma increased by 3.7% among males (95% UI: 3.42, 3.98), and by 7.3% in females (95% UI: 7.01, 7.59).

CONCLUSIONS

Within the last two decades, glaucoma has remained a major cause of blindness globally and regionally.

Comparison of disease severity in glaucoma patients identified by screening in the 1990s and in routine clinical care in the 2010s in Sweden

BACKGROUND AND PURPOSE

In a previous study comparing the amount of visual field damage at presentation in patients having open-angle glaucoma (OAG) identified through screening and in patients diagnosed in routine clinical practice in the 1990s, the damage was considerably worse in the clinically diagnosed patients. In the present study we compare visual field damage at presentation in the same 402 screened patients with that seen in 281 newly detected previously untreated patients clinically diagnosed in the 2010s.

METHODS

The perimetric visual field index mean deviation (MD) was compared in the two groups of patients.

RESULTS

In the clinical patients diagnosed with bilateral visual field damage the median MD was -5.1 dB in the better eye and -13.0 dB in the worse eye. In the screened patients the median MD in the better eye was -6.5 dB and -11.5 dB in the worse eye. The differences between the clinical and screened patients were non-significant, p = 0.28 and p = 0.67 respectively. More clinical patients had severe visual field loss, defined as MD less than -20 dB, in the worse eye than in the screened patients, 18.5% versus 12.7% respectively, p = 0.037.

CONCLUSION

The visual field damage at presentation in clinically diagnosed OAG patients has improved in the past 20 years, but the proportion of patients with severe visual field loss in at least one eye, almost 20%, is still unacceptably high considering that severe visual field damage at presentation is the most important risk factor for later development of glaucoma blindness.

The Finnish current care guideline for open-angle glaucoma

This article is an English translation of the 4th Finnish Current Care Guideline for diagnostics, treatment and follow-up of primary open-angle glaucoma, normal-tension glaucoma and pseudoexfoliative glaucoma. This guideline is based on systematic literature reviews and expert opinions with Finland's geographical and operational healthcare environment in mind.

Evaluation of Reporting Quality of Glaucoma Randomized Controlled Trial Abstracts: Current Status and Future Perspectives

The aim of this study was to explore adherence to the Consolidated Standards of Reporting Trials (CONSORT) reporting standards in abstracts of randomized controlled trials on glaucoma. A cross-sectional observational study was conducted on the aforementioned abstracts, indexed in MEDLINE/PubMed between the years 2017 and 2021. In total, 302 abstracts met the inclusion criteria and were further analyzed. The median score of CONSORT-A items was 8 (interquartile range, 7-10) out of 17 (47.0%). Most analyzed studies were conducted in a single center (80.5%) and the abstracts were predominantly structured (95.0%). Only 20.5% of the abstracts adequately described the trial design, while randomization and funding were described by 6.0% of the abstracts. Higher overall scores were associated with structured abstracts, a multicenter setting, statistically significant results, funding by industry, a higher number of participants, and having been published in journals with impact factors above four (p < 0.001, respectively). The results of this study indicate a suboptimal adherence to CONSORT-A reporting standards, especially in particular items such as randomization and funding. Since these factors could contribute to the overall quality of the trials and further translation of trial results into clinical practice, an improvement in glaucoma research reporting transparency is needed.

[Awareness for glaucoma in the general population]

BACKGROUND

Glaucoma is not a rare entity but because very few symptoms occur and visual field defects are frequently first recognized at a late stage, a large proportion of glaucoma diseases remain undetected. The aim of this study was to identify the proportion of undiagnosed glaucoma in German population-based cohort studies and to contextualize them in the context of the literature.

MATERIAL AND METHODS

The prevalence of glaucoma in the Gutenberg Health Study (GHS) and the age-related investigations on health of the University of Regensburg (AugUR) was evaluated based on visual field examinations and optic disc color photography according to the ISGEO criteria. Furthermore, the self-reported glaucoma diagnoses were collected and the proportion of undiagnosed glaucoma was determined.

RESULTS

The proportion of undiagnosed glaucoma was 55% in the GHS, and 53% in the AugUR study. The results correlate with results from previous studies from other countries in which the proportion of unrecognized glaucoma ranged from 33% to 78%. In the GHS and the AugUR study the proportion of undiagnosed glaucoma was higher in younger age groups and in women.

DISCUSSION

Roughly every second case of glaucoma is undetected. As the symptoms are often nonspecific or take a long time to appear, there is a risk of advanced glaucomatous visual field defects or blindness due to a lack of glaucoma awareness. Studies have shown that a systematic screening can halve this risk.

Social Deprivation and the Risk of Screening Positive for Glaucoma in the MI-SIGHT Telemedicine-Based Glaucoma Detection Program

PURPOSE

To assess whether increased poverty is associated with increased risk of screening positive for glaucoma or suspected glaucoma in a large public screening and intervention program.

DESIGN

Cross-sectional study from 2020 to 2022.

PARTICIPANTS

Adults ≥ 18 years old without acute ocular symptoms.

METHODS

Michigan Screening and Intervention for Glaucoma and eye Health through Telemedicine (MI-SIGHT) program participants' sociodemographic characteristics and area deprivation index (ADI) values were summarized from the clinical sites, which included a free clinic and a Federally Qualified Health Center (FQHC). The ADI, a composite measure of neighborhood deprivation (range, 1-10; 10 is worst deprivation), was assigned on the basis of the participants' addresses. Group comparisons were performed via 2-sample t tests or Wilcoxon Mann-Whitney tests for continuous measures and chi-square tests or Fisher exact tests with Monte Carlo simulation for categorical measures; Holm adjustment was used for multiple comparisons.

MAIN OUTCOME MEASURES

Risk factors for screening positive for glaucoma or suspected glaucoma.

RESULTS

Of the 1171 enrolled participants, 1165 (99.5%) completed the screening: 34% at the free clinic and 66% at the FQHC. Participants were on average aged 55.1 ± 14.5 years, 62% were women, 54% self-reported as Black/African-American, 34% White, 10% Hispanic or Latino, and 70% earned < $30 000 annually. The mean ADI was 7.2 ± 3.1. The FQHC had higher (worse) ADI than the free clinic (free clinic: 4.5 ± 2.9, FQHC: 8.5 ± 2.1, P < 0.0001). One-quarter (24%) of participants screened positive for glaucoma or suspected glaucoma. Screening positive for glaucoma or suspected glaucoma was associated with being older (P = 0.01), identifying as Black/African-American (P = 0.0001), having an established eyecare clinician (P = 0.0005), and not driving a personal vehicle to the appointment (P = 0.001), which is a proxy for increased poverty. Participants who screened positive had worse ADI than those who screened negative (7.7 ± 2.8 vs. 7.0 ± 3.2, P = 0.002). A larger percentage of White participants screened positive at the FQHC compared with White participants at the free clinic (21.3% vs. 12.3%, P = 0.01). FQHC White participants had worse ADI than free clinic White participants (7.5 ± 2.5 vs. 3.7 ± 2.7, P < 0.0001).

CONCLUSIONS

Personal poverty, assessed as not driving a personal vehicle to the appointment, and neighborhood-level poverty were both associated with increased rates of screening positive for glaucoma or suspected glaucoma.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

[Primary Open Angle Glaucoma]

Primary open angle glaucoma is the most frequent type among the glaucomas. It is characterized by a progressive loss of retinal ganglion cells and a corresponding visual field loss. Risk factors include older age, ethnicity, family history of glaucoma and, most important, an elevated intraocular pressure (IOP). The IOP is the only modifiable risk factor for glaucoma progression. Therapeutic approaches aim to lowering the IOP and incorporate topical pressure lowering medication, laser treatment, and different surgical approaches. Surgery aims to reducing the outflow resistance of the aqueous humor. This may be achieved by surgically opening the trabecular meshwork or Schlemm's canal. Penetrating glaucoma surgery comprises classic trabeculectomy and other draining devices.

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.

Fellow of the European board of ophthalmology glaucoma examination and diploma (FEBOS-Gl): update on 8 years of experience and future perspectives

Glaucoma is the leading cause of irreversible blindness worldwide. Early diagnosis and appropriate management of the disease are essential to avoid a significant impact on the quality of life of millions of patients and the socioeconomic impact on societies. Education is the hallmark of good medical care. The European Glaucoma Society (EGS) has dedicated significant efforts to provide means of improving education, training, and testing knowledge in the field of glaucoma. The Fellow of the European Board of Ophthalmology Subspecialty (FEBOS)-Glaucoma examination, introduced and organized yearly by the EGS since 2015 in collaboration with the European Board of Ophthalmology (EBO), has become a valuable tool for increasing overall knowledge in the field. Over the 8 years of experience, several updates and new projects have emerged around the examination to further increase the overall quality of education, training, and knowledge in the field of glaucoma in Europe, particularly in UEMS and associated countries. This article discusses in detail the various projects and measures introduced by the EGS.

Epidemiology, Translation and Clinical Research of Ophthalmology

The human eye is a complex and vital organ that plays a significant role in maintaining a high quality of human life [...].

Home Monitoring of Glaucoma Using a Home Tonometer and a Novel Virtual Reality Visual Field Device: Acceptability and Feasibility

OBJECTIVE

Our aim was to assess the acceptability and feasibility of iCare HOME tonometer (HT) and Virtual Field (VF) devices in the home monitoring of glaucoma.

DESIGN

Prospective feasibility and acceptability study.

SUBJECTS

Twenty patients (39 eyes) with primary open-angle glaucoma, open-angle glaucoma, ocular hypertension, or suspected glaucoma.

METHODS

Patients were trained and instructed to bring 2 devices home for 1 week and use the HT 4 times/day for 4 days and the VF 3 times total.

MAIN OUTCOME MEASURES

For acceptability, we conducted satisfaction surveys and semistructured, qualitative interviews with a thematic analysis. Feasibility was assessed by device usage and quality of tests.

RESULTS

Most patients (73.7%) felt that the HT was easy to use, and 100% of them found the HT useful. All patients (100%) felt that VF was easy to use, and 94.4% of them found the VF useful. All patients (100%) obtained acceptable intraocular pressure and completed a VF test at home. We identified 4 key themes, with 33 subthemes. The key themes include the following: (1) advantages of home monitoring; (2) difficulties with home monitoring; (3) future considerations in home monitoring; and (4) the experience of patients with glaucoma.

CONCLUSIONS

The HT and VF were acceptable and feasible in a small cohort of motivated subjects. Patients were able to perform these tests proficiently at home, and they were generally enthused to obtain more data about their intraocular health, as it allowed them a heightened sense of security and insight about their chronic disease, as well as a reduction in foreseeable barriers to care. Home monitoring may also improve upon glaucoma care by enhancing patient empowerment and fostering community bonds. The VF should be further evaluated to ensure validity.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.

Characteristics of a large, labeled dataset for the training of artificial intelligence for glaucoma screening with fundus photographs

Purpose

Significant visual impairment due to glaucoma is largely caused by the disease being detected too late.

Objective

To build a labeled data set for training artificial intelligence (AI) algorithms for glaucoma screening by fundus photography, to assess the accuracy of the graders, and to characterize the features of all eyes with referable glaucoma (RG).

Design

Cross-sectional study.

Subjects

Color fundus photographs (CFPs) of 113 893 eyes of 60 357 individuals were obtained from EyePACS, California, United States, from a population screening program for diabetic retinopathy.

Methods

Carefully selected graders (ophthalmologists and optometrists) graded the images. To qualify, they had to pass the European Optic Disc Assessment Trial optic disc assessment with ≥ 85% accuracy and 92% specificity. Of 90 candidates, 30 passed. Each image of the EyePACS set was then scored by varying random pairs of graders as "RG," "no referable glaucoma (NRG)," or "ungradable (UG)." In case of disagreement, a glaucoma specialist made the final grading. Referable glaucoma was scored if visual field damage was expected. In case of RG, graders were instructed to mark up to 10 relevant glaucomatous features.

Main Outcome Measures

Qualitative features in eyes with RG.

Results

The performance of each grader was monitored; if the sensitivity and specificity dropped below 80% and 95%, respectively (the final grade served as reference), they exited the study and their gradings were redone by other graders. In all, 20 graders qualified; their mean sensitivity and specificity (standard deviation [SD]) were 85.6% (5.7) and 96.1% (2.8), respectively. The 2 graders agreed in 92.45% of the images (Gwet's AC2, expressing the inter-rater reliability, was 0.917). Of all gradings, the sensitivity and specificity (95% confidence interval) were 86.0 (85.2-86.7)% and 96.4 (96.3-96.5)%, respectively. Of all gradable eyes (n = 111 183; 97.62%) the prevalence of RG was 4.38%. The most common features of RG were the appearance of the neuroretinal rim (NRR) inferiorly and superiorly.

Conclusions

A large data set of CFPs was put together of sufficient quality to develop AI screening solutions for glaucoma. The most common features of RG were the appearance of the NRR inferiorly and superiorly. Disc hemorrhages were a rare feature of RG.

Financial Disclosures

Proprietary or commercial disclosure may be found after the references.

Estimating the Length of the Preclinical Detectable Phase for Open-Angle Glaucoma

Importance

A 50% reduction of glaucoma-related blindness has previously been demonstrated in a population that was screened for open-angle glaucoma. Ongoing screening trials of high-risk populations and forthcoming low-cost screening methods suggest that such screening may become more common in the future. One would then need to estimate a key component of the natural history of chronic disease, the mean preclinical detectable phase (PCDP). Knowledge of the PCDP is essential for the planning and early evaluation of screening programs and has been estimated for several types of cancer that are screened for.

Objective

To estimate the mean PCDP for open-angle glaucoma.

Design, Setting, and Participants

A large population-based screening for open-angle glaucoma was conducted from October 1992 to January 1997 in Malmö, Sweden, including 32 918 participants aged 57 to 77 years. A retrospective medical record review was conducted to assess the prevalence of newly detected cases at the screening, incidence of new cases after the screening, and the expected clinical incidence, ie, the number of new glaucoma cases expected to be detected without a screening. The latter was derived from incident cases in the screened age cohorts before the screening started and from older cohorts not invited to the screening. A total of 2029 patients were included in the current study. Data were analyzed from March 2020 to October 2021.

Main Outcomes and Measures

The length of the mean PCDP was calculated by 2 different methods: first, by dividing the prevalence of screen-detected glaucoma with the clinical incidence, assuming that the screening sensitivity was 100% and second, by using a Markov chain Monte Carlo (MCMC) model simulation that simultaneously derived both the length of the mean PCDP and the sensitivity of the screening.

Results

Of 2029 included patients, 1352 (66.6%) were female. Of 1420 screened patients, the mean age at screening was 67.4 years (95% CI, 67.2-67.7). The mean length of the PCDP of the whole study population was 10.7 years (95% CI, 8.7-13.0) by the prevalence/incidence method and 10.1 years (95% credible interval, 8.9-11.2) by the MCMC method.

Conclusions and Relevance

The mean PCDP was similar for both methods of analysis, approximately 10 years. A mean PCDP of 10 years found in the current study allows for screening with reasonably long intervals, eg, 5 years.

Screening for Glaucoma in Adults: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force

IMPORTANCE

Two 2013 systematic reviews to inform the US Preventive Services Task Force (USPSTF) found insufficient evidence to assess benefits and harms of screening for primary open-angle glaucoma (OAG) in adults.

OBJECTIVE

To update the 2013 reviews on screening for glaucoma, to inform the USPSTF.

DATA SOURCES

Ovid MEDLINE, the Cochrane Central Register of Controlled Trials, and the Cochrane Database of Systematic Reviews (to February 2021); surveillance through January 21, 2022.

STUDY SELECTION

Randomized clinical trials (RCTs) of screening, referral, and treatment; and studies of screening test diagnostic accuracy.

DATA EXTRACTION AND SYNTHESIS

One investigator abstracted data and a second checked accuracy. Two investigators independently assessed study quality.

RESULTS

Eighty-three studies (N = 75 887) were included (30 trials and 53 diagnostic accuracy studies). One RCT (n = 616) found screening of frail elderly persons associated with no difference in vision outcomes vs no screening but with significantly greater falls risk (relative risk [RR], 1.31 [95% CI, 1.13-1.50]). No study evaluated referral to an eye health professional. For glaucoma diagnosis, spectral domain optical coherence tomography (providing high-resolution cross-sectional imaging; 15 studies, n = 4242) was associated with sensitivity of 0.79 (95% CI, 0.75-0.83) and specificity of 0.92 (95% CI, 0.87-0.96) and the Humphrey Visual Field Analyzer (for perimetry, or measurement of visual fields; 6 studies, n = 11 244) with sensitivity of 0.87 (95% CI, 0.69-0.95) and specificity 0.82 (95% CI, 0.66-0.92); tonometry (for measurement of intraocular pressure; 13 studies, n = 32 892) had low sensitivity (0.48 [95% CI, 0.31-0.66]). Medical therapy for ocular hypertension and untreated glaucoma was significantly associated with decreased intraocular pressure and decreased likelihood of glaucoma progression (7 trials, n = 3771; RR, 0.68 [95% CI, 0.49-0.96]; absolute risk difference -4.2%) vs placebo, but 1 trial (n = 461) found no differences in visual acuity, quality of life, or function. Selective laser trabeculoplasty and medical therapy had similar outcomes (4 trials, n = 957).

CONCLUSIONS AND RELEVANCE

This review found limited direct evidence on glaucoma screening, showing no association with benefits. Screening tests can identify persons with glaucoma and treatment was associated with a lower risk of glaucoma progression, but evidence of improvement in visual outcomes, quality of life, and function remains lacking.

The analysis of the glaucoma screening event results obtained during the World Glaucoma Week in Zagreb, Croatia

PURPOSE

To report the prevalence of undiagnosed glaucoma, as well as demographic characteristics and risk factors among glaucoma suspects who were detected in a publicly promoted intraocular pressure (IOP) based glaucoma screening event.

METHODS

A total of 2468 subjects older than 18 years participated in the glaucoma screening event in Zagreb, in 2014, which included a medical interview and IOP measurement using Icare tonometer. 256 subjects (10.37%) were identified as glaucoma suspects, out of which 125 (5.06%) subjects underwent further detailed ophthalmic examination and were classified into five diagnostic groups.

RESULTS

The prevalence of all types of newly diagnosed glaucoma was 1.175%, while the prevalence of ocular hypertension (OH), primary open-angle glaucoma (POAG), primary angle closure (PAC) and secondary glaucoma (SG) was 0.16%, 0.89%, 0.16% and 0.12%, respectively. The prevalence of newly diagnosed glaucoma in glaucoma suspects was 23.2%. 17.60% of glaucoma suspects were diagnosed as POAG. Older age was statistically significantly associated with POAG (p = 0.001) and PAC (p = 0.029). At the univariate level, refractive errors were a statistically significant predictor of POAG, and those with hyperopia had more than three times larger odds for POAG. At the multivariate level, none of the predictors reached statistical significance.

CONCLUSION

Successful cooperation between healthcare institutions and media can be a useful way of increasing awareness and detection of individuals at an increased risk for developing glaucoma.