A Health-Related Quality of Life Measure for Patients Who Undergo Minimally Invasive Glaucoma Surgery.

PURPOSE: To develop a standardized patient-reported outcome measure to assess the impact of glaucoma and treatment, including minimally invasive glaucoma surgery (MIGS), on health-related quality of life (HRQOL). DESIGN: Observational study before and after concomitant cataract and FDA-approved implantable MIGS device surgery to provide information on the measure's performance in assessing HRQOL. METHODS SETTING: Survey administration was done by electronic patient-reported outcomes (ePRO) application to patients at multiple sites on a computer, iPad, or similar device. PATIENT POPULATION: One hundred eighty-four adults completed a baseline survey, 124 completed a survey 3 months after surgery, and 106 completed the 1-month test-retest reliability survey. The age range was 37-89, and the average age was 72. Most of the respondents were female (57%), non-Hispanic White (81%), and had a college degree (56%). MAIN OUTCOME MEASURES: The Glaucoma Outcomes Survey (GOS) includes 42 questions assessing functional limitations (27 items), vision-related symptoms (7 items), psychosocial issues (7 items) and satisfaction with microinvasive glaucoma surgery (1 item). The three multiple-item scales were scored on a 0-100 range, with a higher score indicating worse health. RESULTS: Internal consistency reliability estimates ranged from 0.75 (vision-related symptoms) to 0.93 (functional limitations) and one-month test-retest intraclass correlations ranged from 0.65 (PROMIS global mental health) to 0.92 (functional limitations). Product-moment correlations among the GOS scales ranged from 0.56 to 0.60. Improvement in visual acuity in the study eye from baseline to the 3-month follow-up was significantly related to improvements in GOS functional limitations (r =0.18, p =0.0485), vision-related symptoms (r = 0.19, p = 0.0386), and psychosocial concerns (r = 0.18, p =0.0503). The highest proportion of responders to treatment was seen for the GOS functional limitations scale (48%), followed by GOS psychosocial issues (21%) and GOS vision-related symptoms (17%). CONCLUSIONS: This study provides initial support for using the GOS instrument in ophthalmic procedures such as MIGS. Further evaluation of the GOS in other samples, including different patient subgroups and clinical settings, will be valuable. The instrument may be useful for evaluations of other treatments for glaucoma.

The TsiogkaSpaeth grid for detection of neurological visual field defects: a validation study.

BACKGROUND: The TsiogkaSpaeth (TS) grid is a new, low-cost, and easy to access portable test for visual field (VF) screening which could be used by clinicians in everyday clinical practice. Our study aimed to determine the validity of an innovative screening grid test for identifying neurological disease-associated VF defects. METHODS: We enrolled two groups of participants: We assessed the one eye of ten consecutive adult patients with different types of neurological disease associated VF defects and ten eyes of controls in each group. The TS grid test was performed in each group. Sensitivity, specificity, and positive and negative predictive values of the TS grid scotoma area were assessed using the 24-2 VF Humphrey field analyzer (HFA) as the reference standard. RESULTS: Sensitivity and specificity of the TS grid test were 100% and 90.91%, respectively. The area under curve was 0.9545 with 95% CI 0.87-1.00. There was a significant correlation between the number of missed locations on the TS grid test and the visual field index of the HFA 24-2 (r = 0.9436, P < .0001). CONCLUSION: The sensitivity and specificity of the TS grid test were high in detecting VF defects in neurological disease. The TS grid test appears to be a reliable, low-cost, and easily accessed alternative to traditional VF tests in diagnosing typical neurological patterns of visual field defects. It would be useful in screening subjects for neurologically derived ocular morbidity in everyday clinical practice and in remote areas deprived of specialized health care services.

European Glaucoma Society - A guide on surgical innovation for glaucoma.

PROLOGUE: Glaucoma surgery has been, for many decades now, dominated by the universal gold standard which is trabeculectomy augmented with antimetabolites. Tubes also came into the scene to complement what we use to call conventional or traditional glaucoma surgery. More recently we experienced a changing glaucoma surgery environment with the "advent" of what we have become used to calling Minimally Invasive Glaucoma Surgery (MIGS). What is the unmet need, what is the gap that these newcomers aim to fill? Hippocrates taught us "bring benefit, not harm" and new glaucoma techniques and devices aim to provide safer surgery compared to conventional surgery. For the patient, but also for the clinician, safety is important. Is more safety achieved with new glaucoma surgery and, if so, is it associated with better, equivalent, or worse efficacy? Is new glaucoma surgery intended to replace conventional surgery or to complement it as an 'add-on' to what clinicians already have in their hands to manage glaucoma? Which surgery should be chosen for which patient? What are the options? Are they equivalent? These are too many questions for the clinician! What are the answers to the questions? What is the evidence to support answers? Do we need more evidence and how can we produce high-quality evidence? This EGS Guide explores the changing and challenging glaucoma surgery environment aiming to provide answers to these questions. The EGS uses four words to highlight a continuum: Innovation, Education, Communication, and Implementation. Translating innovation to successful implementation is crucially important and requires high-quality evidence to ensure steps forward to a positive impact on health care when it comes to implementation. The vision of EGS is to provide the best possible well-being and minimal glaucomainduced visual disability in individuals with glaucoma within an affordable healthcare system. In this regard, assessing the changes in glaucoma surgery is a pivotal contribution to better care. As mentioned, this Guide aims to provide answers to the crucial questions above. However, every clinician is aware that answers may differ for every person: an individualised approach is needed. Therefore, there will be no uniform answer for all situations and all patients. Clinicians would need, through the clinical method and possibly some algorithm, to reach answers and decisions at the individual level. In this regard, evidence is needed to support clinicians to make decisions. Of key importance in this Guide is to provide an overview of existing evidence on glaucoma surgery and specifically on recent innovations and novel devices, but also to set standards in surgical design and reporting for future studies on glaucoma surgical innovation. Designing studies in surgery is particularly challenging because of many subtle variations inherent to surgery and hence multiple factors involved in the outcome, but even more because one needs to define carefully outcomes relevant to the research question but also to the future translation into clinical practice. In addition this Guide aims to provide clinical recommendations on novel procedures already in use when insufficient evidence exists. EGS has a long tradition to provide guidance to the ophthalmic community in Europe and worldwide through the EGS Guidelines (now in their 5th Edition). The EGS leadership recognized that the changing environment in glaucoma surgery currently represents a major challenge for the clinician, needing specific guidance. Therefore, the decision was made to issue this Guide on Glaucoma Surgery in order to help clinicians to make appropriate decisions for their patients and also to provide the framework and guidance for researchers to improve the quality of evidence in future studies. Ultimately this Guide will support better Glaucoma Care in accordance with EGS's Vision and Mission. Fotis Topouzis EGS President

Correlation between Central Visual Field Defects and Stereopsis in Patients with Early-to-Moderate Visual Field Loss.

PURPOSE: To investigate the association between stereoacuity and the presence of central visual field defects (CVFDs) due to glaucoma. DESIGN: A prospective, cross-sectional cohort study. PARTICIPANTS: Participants with early-to-moderate glaucoma with a visual acuity better than 20/40, less than a 2-line difference in visual acuity between eyes, and 2 reliable Humphrey visual fields (VFs) (24-2 SITA standard) with mean deviation (MD) in the worse eye better than - 12 dB. METHODS: Stereoacuity was measured using the Titmus stereo test. Participants with a significant field defect (P < 0.005) in any 1 of the central 4 points in the 24-2 SITA standard total deviation map in either eye were classified as having a CVFD. Vision-related quality of life (VR-QOL) was measured using 25-item National Eye Institute Visual Function Questionnaire scores. Logistic regression was used to determine the associations between the level of stereoacuity and age, sex, race, glaucoma type, presence of CVFDs, visual acuity, contrast sensitivity, and VF MD. MAIN OUTCOME MEASURES: Stereoacuity in the CVFD and non-CVFD groups. RESULTS: Sixty-five participants met the inclusion criteria. The mean age of the participants was 64.3 ± 8.0 years, and 64.6% were women. The median stereoacuity was 60 arc seconds (interquartile range [IQR], 40-120 arc seconds). Forty-two (65%) patients had CVFDs, and 23 (35%) patients did not. The median stereoacuity of the CVFD group was worse than that of the non-CVFD group (60 arc seconds [IQR, 50-140 arc seconds] vs. 40 arc seconds [IQR, 40-80 arc seconds], respectively; P = 0.001). The non-CVFD group had a higher percentage of participants with normal stereopsis than the non-CVFD group (61% vs. 21%, respectively; P = 0.001). A multivariable analysis found that the presence of CVFDs was associated with worse stereopsis levels (odds ratio, 4.49; P = 0.021). The CVFD group had a lower Visual Functioning Questionnaire-25 (VFQ-25) composite score (84.0 vs. 91.4; P = 0.004) and lower VFQ-25 subscale scores for general vision, near activities, and mental health (P < 0.05). CONCLUSIONS: Central visual field defects were associated with increased odds of poor stereoacuity in patients with early-to-moderate glaucomatous VF loss. Specifically, patients without CVFDs are more likely to have normal stereopsis and higher VR-QOL than those with CVFDs. Patients with CVFDs should be counseled regarding how depth perception difficulties may affect daily living. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Comparison of Central and Peripheral Contrast Sensitivity Between Healthy and Refractive Surgery Patients Using the Spaeth/Richman Contrast Sensitivity (SPARCS) Test.

PURPOSE: To assess contrast sensitivity of central and peripheral vision with a newly developed, internet-based Spaeth/Richman Contrast Sensitivity (SPARCS) test in patients who underwent myopic photorefractive keratectomy (PRK) or femtosecond laser-assisted laser in situ keratomileusis (FSLASIK) refractive surgery in comparison with controls. METHODS: In a retrospective study, a total of 186 eyes from 93 patients were analyzed: 62 eyes from 31 patients for each of the three groups under comparison. Patients who underwent a refractive surgery procedure and controls were evaluated using the SPARCS test. SPARCS scores were obtained for central and four peripheral areas (right upper, right lower, left upper, and left lower quadrants). Total, central, and peripheral SPARCS scores in patients with refractive surgery were compared with controls, adjusting for possible confounders. Multivariate and mixed linear regression models were used. RESULTS: Patients who had PRK had a lower score in all categories compared with the control group: by 5.9 points (95% CI: -9 to -2.8) in the total score, by 1.6 points (95% CI: -3 to -0.3) in the central score, and by 5.5 points (95% CI: -9.4 to -1.6) in the peripheral score. Patients who had FS-LASIK had non-statistically significant lower scores than the control group. CONCLUSIONS: PRK causes a decrease in central and peripheral contrast sensitivity. [J Refract Surg. 2022;38(2):128-133.].

Vision-Targeted Health-Related Quality-of-Life Survey for Evaluating Minimally Invasive Glaucoma Surgery.

PURPOSE: To develop a vision-targeted health-related quality-of-life instrument for patients with glaucoma who are candidates for minimally invasive glaucoma surgery (MIGS). DESIGN: Development of a health-related quality-of-life instrument. PARTICIPANTS: Twelve practicing ophthalmologists and 41 glaucoma patients. METHODS: A questionnaire was constructed to assess functional limitations, vision-related symptoms, aesthetics, psychosocial issues, and surgical satisfaction for MIGS candidates. Questions were drafted after a review of the literature and subsequently refined based upon input from 1 physician and 4 patient focus groups. Nineteen cognitive interviews were used to ensure that questions were understandable to respondents. RESULTS: The focus group identified the following key issues and concerns as being important to glaucoma patients: functional limitations (eg, driving), bodily discomfort (eg, stinging from drops), changes in appearance (eg, drooping eyelid), and psychosocial concerns (eg, mental burden associated with a diagnosis of glaucoma, financial burden of treatment). Cognitive interviews resulted in the following improvements to the questionnaire: changes in wording to clarify lighting conditions, and additional questions addressing psychosocial issues, such as job loss, severity of disease, and perception of MIGS. CONCLUSIONS: A patient-reported outcomes instrument, the Glaucoma Outcomes Survey, was developed to evaluate MIGS for patients with mild to moderate glaucoma. Next steps include electronic administration to patients selected from the American Academy of Ophthalmology Intelligent Research in Sight (IRIS) registry. An electronic patient-reported outcomes platform will be used to administer the questionnaire before and after MIGS. The questionnaire will improve understanding of how surgical interventions such as MIGS impact vision-targeted health-related quality-of-life in glaucoma patients.

Improvement in structure and visual function in patients with glaucoma: the possible key to better treatment?

Glaucoma is characterized by retinal ganglion cell loss that can lead to permanent visual loss. Current clinical management practice assumes that glaucomatous visual loss is irreversible; however, there is increasing evidence that permanent vision loss and cell death are preceded by reversible functional and structural changes. We propose that these changes should be considered by glaucoma specialists when treating their patients. We discuss the neurobiological basis of this phenomenon and provide clinical evidence of reversibility in both structure and function. Specifically, we review the findings of visual field testing, contrast sensitivity, electroretinography, and imaging of the optic nerve and their correlation with functional changes. We then discuss the clinical value of these observations in helping guide approaches toward the diagnosis and treatment of patients with glaucoma.

Cataract Surgery (Phacoemulsification with Intraocular Lens Implantation) Combined with Endoscopic Goniosynechialysis for Advanced Primary Angle-Closure Glaucoma.

PURPOSE: To evaluate the efficacy and risk of cataract surgery (phacoemulsification with intraocular lens [IOL] implantation) combined with endoscopic goniosynechialysis (EGSL) for advanced primary angle-closure glaucoma (PACG). DESIGN: Retrospective, continuous case series. PARTICIPANTS: A total of 16 patients (18 eyes) with advanced PACG were enrolled in this study between February 2014 and March 2016. Advanced glaucoma inclusion criteria were based on the method proposed in the Advanced Glaucoma Intervention Study, with a visual field score of 18 points or more. METHODS: All patients underwent cataract surgery with EGSL by the same experienced surgeon. Paired t test and generalized estimating equation analyses were performed. MAIN OUTCOME MEASURES: The extent of peripheral anterior synechiae (PAS), number of intraocular pressure (IOP)-lowering drugs, IOP, best-corrected visual acuity (BCVA), and visual fields before and after surgery. The incidence of complications was recorded. RESULTS: The mean follow-up duration was 13.8 months (standard deviation, 2.7 months). The mean difference (preoperative minus postoperative) in PAS was 202.7° (95% confidence interval [CI], 43.5°). The mean difference (preoperative minus postoperative) in the number of IOP-lowering drugs and IOP was 2.0 (95% CI, ±0.5), and 9.4 mmHg (95% CI, ±2.1 mmHg) respectively. The mean improvement in BCVA was 0.29 logMAR (95% CI, ±0.14). A positive correlation was found between the extent of postoperative PAS and postoperative IOP (B = 8.2; P < 0.001) and also between postoperative PAS and postoperative number of IOP-lowering drugs (B = 28.9; P < 0.001). Anterior chamber hemorrhage and exudation occurred in 4 patients and 2 patients, respectively, after surgery. Posterior capsular opacification occurred in 5 patients after surgery. CONCLUSIONS: Cataract surgery with EGSL could be an effective surgical method for the treatment of advanced PACG.

Keratoconus with Central Serous Chorioretinopathy: A Rare Combination.

Keratoconus and central serous chorioretinopathy are two rare diseases. They can occur together in some individuals. We report a case of a 48-year-old man, who presented to our clinic with decreased visual acuity on his left eye. Physical examination, biomicroscopy, corneal topography, and optical coherence tomography revealed keratoconus and central serous chorioretinopathy. We discuss the possible connection between these two conditions.

Patient-reported outcomes measures and patient preferences for minimally invasive glaucoma surgical devices.

BACKGROUND: Many therapeutic options are available to glaucoma patients. One recent therapeutic option is minimally invasive glaucoma surgical (MIGS) devices. It is unclear how patients view different treatments and which patient-reported outcomes would be most relevant in patients with mild to moderate glaucoma. We developed a questionnaire for patients eligible for MIGS devices and a patient preference study to examine the value patients place on certain outcomes associated with glaucoma and its therapies. OBJECTIVES: To summarize the progress to date. METHODS: Questionnaire development: We drafted the questionnaire items based on input from one physician and four patient focus groups, and a review of the literature. We tested item clarity with six cognitive interviews. These items were further refined. Patient preference study: We identified important benefit and risk outcomes qualitatively using semi-structured, one-on-one interviews with patients who were eligible for MIGS devices. We then prioritized these outcomes quantitatively using best-worst scaling methods. RESULTS: Questionnaire testing: Three concepts were deemed relevant for the questionnaire: functional limitations, symptoms, and psychosocial factors. We will evaluate the reliability and validity of the 52-item draft questionnaire in an upcoming field test. Patient preference study: We identified 13 outcomes that participants perceived as important. Outcomes with the largest relative importance weights were "adequate IOP control" and "drive a car during the day." CONCLUSIONS: Patients have the potential to steer clinical research towards outcomes that are important to them. Incorporating patients' perspectives into the MIGS device development and evaluation process may expedite innovation and availability of these devices.

Contrast Sensitivity and Glaucoma.

Spatial contrast sensitivity decline occurs in different types and stages of glaucoma. In this short review we discuss methods of assessing contrast sensitivity, the role of contrast sensitivity in the pathogenesis of glaucoma and its practical application in clinical practice.

Glaucoma-Associated Visual Task Performance and Vision-Related Quality of Life in South India.

Objective/Purpose: Performance-based measures may provide an objective assessment of how glaucoma affects daily functioning. We sought to validate a clinically-applicable performance-based measure of visual ability for patients with glaucoma in south India and to describe its relationship to clinical and patient-reported outcomes. Design: Cross-sectional validation study. Subjects/Participants/Controls: 145 participants with glaucoma were recruited at Aravind Eye Hospital. Methods/Intervention/Testing: We modified the compressed assessment of activities related to vision (CAARV), a performance-based measure validated in the U.S., to be culturally relevant in south India. Participants underwent a series of tests, including the Indian CAARV (I-CAARV), Indian Visual Functioning Questionnaire (IND-VFQ), Spaeth/Richman Contrast Sensitivity (SPARCS) test, standard automated perimetry, and visual acuity (VA). Factor analysis and Rasch modeling were used to validate the I-CAARV. Correlations between the I-CAARV and other outcomes were evaluated. Main Outcome Measure: Psychometric properties of the I-CAARV for individuals with glaucoma in south India. Results: The study included 142 participants (51.7% female, mean age 56.4 years). Average presenting visual acuity and visual field mean deviation (MD) in the better-seeing eye were 0.26 logMAR and -6.57 dB, respectively. The four tasks of the I-CAARV were found to measure a single underlying construct. Rasch analysis of the I-CAARV revealed that the outcome measure had moderate reliability, good construct and content validity, and fair measurement precision. Tasks were well-targeted to the study sample. Rasch-calibrated scores on the I-CAARV were significantly correlated with Rasch-calibrated IND-VFQ scores (r=-0.54) and with visual field MD, presenting VA, best-corrected VA, and SPARCS contrast sensitivity in both the better-seeing eye (r=0.60, -0.51, -0.53, 0.76, respectively) and worse-seeing eye (r=0.48, -0.61, -0.46, 0.69, respectively). Conclusions: The I-CAARV is a valid performance-based measure of vision-dependent functioning in glaucoma in south India. This study also found that I-CAARV task performance was strongly correlated with contrast sensitivity and suggests that performance-based and patient-reported outcomes are related but distinct measures of the impact of glaucoma on functioning and vision-related quality of life. Future studies are needed to determine the sensitivity of the I-CAARV to detect changes due to disease progression that are relevant to functioning and vision-related quality of life.

Association of Preoperative Disclosure of Resident Roles With Informed Consent for Cataract Surgery in a Teaching Program.

IMPORTANCE: Cataract surgery is the most commonly performed intraocular surgery. Academic centers have mandates to train the next surgeon generation, but resident roles are often hidden in the consent process. OBJECTIVE: To investigate associations of full preoperative disclosure of the resident role with patient consent rates and subjective experience of the consent process. DESIGN, SETTING, AND PARTICIPANTS: Full scripted disclosure of residents' roles in cataract surgery was delivered by the attending surgeon. Qualitative analysis was conducted from recorded interviews of patients postoperatively regarding consent process experience and choice of whether to allow resident participation. Associations were sought regarding demographic characteristics and consent rates. Patients were recruited though a private community office. Surgery was performed at a single hospital where resident training was routinely conducted. The study included systemically well patients older than 18 years with surgical cataract. They had no previous eye surgery, English fluency, and ability to engage in informed consent decision-making and postsurgery interview. Patients were ineligible if they had monocular cataracts, required additional simultaneous procedures, had history of ocular trauma, or had cataracts that were surgically technically challenging beyond the usual resident skill level. INTERVENTIONS: Eligible patients received an informed consent conversation by the attending physician in accordance with a script describing projected resident involvement in their cataract surgery. Postoperatively, patients were interviewed and responses were analyzed with a quantitative and thematic qualitative approach. MAIN OUTCOMES AND MEASURES: Consent rates to resident participation and qualitative experience of full disclosure process. RESULTS: Ninety-six patients participated. Participants were between ages 50 and 88 years, 53 were men (55.2%), and 75 were white (85.2%). A total of 54 of 96 participants (56.3%; 95% CI, 45.7%-66.4%) agreed to resident involvement. There were no associations between baseline characteristics and consent to resident involvement identified with any confidence, including race/ethnicity (60% [45 of 75] in white patients vs 30.8% [4 of 13] in nonwhite patients; difference, 29.2%; 95% CI, -0.7% to 57.3%; Fisher exact P = .07). Thematically, those who agreed to resident involvement listed trust in the attending surgeon, contributing to education, and supervision as contributing factors. Patients who declined stated fear and perceived risk as reasons. CONCLUSIONS AND RELEVANCE: Our results suggest 45.7% to 66.4% of community private practice patients would consent to resident surgery. Consent rates were not associated with demographic factors. Because residents are less often offered the opportunity to do surgery on private practice patients vs academic center patients, this may represent a resource for resident education.

Measuring Contrast Sensitivity in Specific Areas of Vision - A Meaningful Way to Assess Quality of Life and Ability to Perform Daily Activities in Glaucoma.

Purpose: To investigate: 1) the impact of reduced contrast sensitivity (CS) in specific areas of vision on subjective assessment of vision-related quality of life (VRQoL) and objective performance-based measures in patients with primary open-angle, primary angle-closure, and pseudoexfoliation glaucoma; and 2) correlations between measurements of contrast sensitivity (CS) in specific areas of vision and visual field (VF) tests. Methods: The Spaeth/Richman Contrast Sensitivity Test (SPARCS) measured CS in the inferior, superior, and central areas, while the Pelli-Robson test measured central CS. Visual fields were tested in participants using standard-automated perimetry. The National Eye Institute Visual Function Questionnaire (NEI-VFQ-25) assessed VRQoL, and the Compressed Assessment of Ability Related to Vision (CAARV) assessed vision-related performance. Results: Three hundred and twenty-two eyes of 161 participants were included in our analysis. Significant correlations were found between CS and VF scores in the inferior, central, and superior areas (P < .0001 for all). Significant correlations were found between SPARCS scores in the inferior areas in both eyes and most CAARV scores (P < .05). Significant correlations were also found between SPARCS scores in the inferior and superior areas in the worse eye and most NEI-VFQ -25 scores (P < .05). Conclusion: Contrast sensitivity and VF scores significantly correlated in all tested areas. Reduced CS in the inferior areas of both eyes affected most performance-based measures. Measurement of CS areas using SPARCS is a meaningful way to assess VRQoL and ability to perform daily activities in participants with glaucoma.

Correction: Accurate, fast, data efficient and interpretable glaucoma diagnosis with automated spatial analysis of the whole cup to disc profile.

[This corrects the article DOI: 10.1371/journal.pone.0209409.].

Accurate, fast, data efficient and interpretable glaucoma diagnosis with automated spatial analysis of the whole cup to disc profile.

BACKGROUND: Glaucoma is the leading cause of irreversible blindness worldwide. It is a heterogeneous group of conditions with a common optic neuropathy and associated loss of peripheral vision. Both over and under-diagnosis carry high costs in terms of healthcare spending and preventable blindness. The characteristic clinical feature of glaucoma is asymmetrical optic nerve rim narrowing, which is difficult for humans to quantify reliably. Strategies to improve and automate optic disc assessment are therefore needed to prevent sight loss. METHODS: We developed a novel glaucoma detection algorithm that segments and analyses colour photographs to quantify optic nerve rim consistency around the whole disc at 15-degree intervals. This provides a profile of the cup/disc ratio, in contrast to the vertical cup/disc ratio in common use. We introduce a spatial probabilistic model, to account for the optic nerve shape, we then use this model to derive a disc deformation index and a decision rule for glaucoma. We tested our algorithm on two separate image datasets (ORIGA and RIM-ONE). RESULTS: The spatial algorithm accurately distinguished glaucomatous and healthy discs on internal and external validation (AUROC 99.6% and 91.0% respectively). It achieves this using a dataset 100-times smaller than that required for deep learning algorithms, is flexible to the type of cup and disc segmentation (automated or semi-automated), utilises images with missing data, and is correlated with the disc size (p = 0.02) and the rim-to-disc at the narrowest rim (p<0.001, in external validation). DISCUSSION: The spatial probabilistic algorithm is highly accurate, highly data efficient and it extends to any imaging hardware in which the boundaries of cup and disc can be segmented, thus making the algorithm particularly applicable to research into disease mechanisms, and also glaucoma screening in low resource settings.

Is primary open-angle glaucoma an ocular manifestation of systemic disease?

Primary open-angle glaucoma is currently characterized by a pattern of progressive retinal ganglion cell loss that stems from a complex underlying pathophysiology that remains poorly elucidated. The roles of blood flow and intraocular pressure (IOP) in glaucoma pathogenesis have been extensively studied. Further, it has been established that lowering IOP can slow the progression of glaucoma. In addition, a number of influential factors have emerged and gained momentum over the years. Increasing evidence implicates the contributions of low cerebrospinal fluid pressure, autoimmunity, neurodegeneration, and impaired autoregulation towards glaucoma pathophysiology. We aggregate and explore these different camps of thought that have garnered attention over the last few decades, and, in doing so, aim to challenge the long-standing view of glaucoma as a primary disease of the eye. A shift in our perspective towards understanding glaucoma as an ocular manifestation of systemic dysregulation may lead ultimately to better clinical management of the disease.