Craig JE, Han X, Qassim A, Hassall M, Cooke Bailey JN, Kinzy TG, Khawaja AP, An J, Marshall H, Gharahkhani P, Igo RP, Graham SL, Healey PR, Ong J-S, Zhou T, Siggs O, Law MH, Souzeau E, Ridge B, Hysi PG, Burdon KP, Mills RA, Landers J, Ruddle JB, Agar A, Galanopoulos A, White AJR, Willoughby CE, Andrew NH, Best S, Vincent AL, Goldberg I, Radford-Smith G, Martin NG, Montgomery GW, Vitart V, Hoehn R, Wojciechowski R, Jonas JB, Aung T, Pasquale LR, Cree AJ, Sivaprasad S, Vallabh NA, Vallabh NA, and Consortium UKBEV, Viswanathan AC, Pasutto F, Haines JL, Klaver CCW, van Duijn CM, Casson RJ, Foster PJ, Khaw PT, Hammond CJ, Mackey DA, Mitchell P, Lotery AJ, Wiggs JL, Hewitt AW, Macgregor S. Multitrait analysis of glaucoma identifies new risk loci and enables polygenic prediction of disease susceptibility and progression. Nat Genet 2020;52(2):160-166.Abstract
Glaucoma, a disease characterized by progressive optic nerve degeneration, can be prevented through timely diagnosis and treatment. We characterize optic nerve photographs of 67,040 UK Biobank participants and use a multitrait genetic model to identify risk loci for glaucoma. A glaucoma polygenic risk score (PRS) enables effective risk stratification in unselected glaucoma cases and modifies penetrance of the MYOC variant encoding p.Gln368Ter, the most common glaucoma-associated myocilin variant. In the unselected glaucoma population, individuals in the top PRS decile reach an absolute risk for glaucoma 10 years earlier than the bottom decile and are at 15-fold increased risk of developing advanced glaucoma (top 10% versus remaining 90%, odds ratio = 4.20). The PRS predicts glaucoma progression in prospectively monitored, early manifest glaucoma cases (P = 0.004) and surgical intervention in advanced disease (P = 3.6 × 10). This glaucoma PRS will facilitate the development of a personalized approach for earlier treatment of high-risk individuals, with less intensive monitoring and treatment being possible for lower-risk groups.
Di Zazzo A, Roberti G, Mashaghi A, Abud TB, Pavese D, Bonini S. Use of Topical Cannabinomimetic Palmitoylethanolamide in Ocular Surface Disease Associated with Antiglaucoma Medications. J Ocul Pharmacol Ther 2017;33(9):670-677.Abstract
PURPOSE: Chronic use of topical hypotensive therapies in glaucoma patients leads to chronic inflammation of the ocular surface, which decreases the success rate of long-term glaucoma management. The aim of this study is to evaluate the effect of topical palmitoylethanolamide (PEA) (Defluxa©), a well-known anti-inflammatory and analgesic agent, in suppressing the ocular surface inflammation associated with the use of hypotensive eye drops. METHODS: In a pilot clinical trial, we enrolled 15 glaucomatous patients who received topical PEA (Defluxa) in addition to the current antiglaucoma drugs, while 15 glaucomatous patients did not receive any additional treatment. At 3 different time points (day 0, 15, and 30), signs of ocular surface involvement, adverse events, visual acuity, and intraocular pressure were assessed. RESULTS: Topical PEA (Defluxa) was effective in increasing the Schirmer test (P < 0.05) and the tear film breakup time (T-BUT) (P < 0.0001), and improving the conjunctival hyperemia (P < 0.0001) by day 30, compared to baseline. Compared to control, by day 15, the conjunctival hyperemia score was significantly decreased in the PEA (Defluxa) group (P < 0.01), while the T-BUT and the Schirmer Test achieved a significant improvement by day 30 (P < 0.05; P < 0.01). DISCUSSION: Our data suggests that topical PEA (Defluxa) is a safe, effective, and generally well-tolerated treatment to prevent or suppress ocular surface inflammation attributable to chronic glaucoma treatment.
Dixit A, Yohannan J, Boland MV. Assessing Glaucoma Progression Using Machine Learning Trained on Longitudinal Visual Field and Clinical Data. Ophthalmology 2021;128(7):1016-1026.Abstract
PURPOSE: Rule-based approaches to determining glaucoma progression from visual fields (VFs) alone are discordant and have tradeoffs. To detect better when glaucoma progression is occurring, we used a longitudinal data set of merged VF and clinical data to assess the performance of a convolutional long short-term memory (LSTM) neural network. DESIGN: Retrospective analysis of longitudinal clinical and VF data. PARTICIPANTS: From 2 initial datasets of 672 123 VF results from 213 254 eyes and 350 437 samples of clinical data, persons at the intersection of both datasets with 4 or more VF results and corresponding baseline clinical data (cup-to-disc ratio, central corneal thickness, and intraocular pressure) were included. After exclusion criteria-specifically the removal of VFs with high false-positive and false-negative rates and entries with missing data-were applied to ensure reliable data, 11 242 eyes remained. METHODS: Three commonly used glaucoma progression algorithms (VF index slope, mean deviation slope, and pointwise linear regression) were used to define eyes as stable or progressing. Two machine learning models, one exclusively trained on VF data and another trained on both VF and clinical data, were tested. MAIN OUTCOME MEASURES: Area under the receiver operating characteristic curve (AUC) and area under the precision-recall curve (AUPRC) calculated on a held-out test set and mean accuracies from threefold cross-validation were used to compare the performance of the machine learning models. RESULTS: The convolutional LSTM network demonstrated 91% to 93% accuracy with respect to the different conventional glaucoma progression algorithms given 4 consecutive VF results for each participant. The model that was trained on both VF and clinical data (AUC, 0.89-0.93) showed better diagnostic ability than a model exclusively trained on VF results (AUC, 0.79-0.82; P < 0.001). CONCLUSIONS: A convolutional LSTM architecture can capture local and global trends in VFs over time. It is well suited to assessing glaucoma progression because of its ability to extract spatiotemporal features that other algorithms cannot. Supplementing VF results with clinical data improves the model's ability to assess glaucoma progression and better reflects the way clinicians manage data when managing glaucoma.
Dordea AC, Bray M-A, Allen K, Logan DJ, Fei F, Malhotra R, Gregory MS, Carpenter AE, Buys ES. An open-source computational tool to automatically quantify immunolabeled retinal ganglion cells. Exp Eye Res 2016;147:50-6.Abstract

A fully automated and robust method was developed to quantify β-III-tubulin-stained retinal ganglion cells, combining computational recognition of individual cells by CellProfiler and a machine-learning tool to teach phenotypic classification of the retinal ganglion cells by CellProfiler Analyst. In animal models of glaucoma, quantification of immunolabeled retinal ganglion cells is currently performed manually and remains time-consuming. Using this automated method, quantifications of retinal ganglion cell images were accelerated tenfold: 1800 images were counted in 3 h using our automated method, while manual counting of the same images took 72 h. This new method was validated in an established murine model of microbead-induced optic neuropathy. The use of the publicly available software and the method's user-friendly design allows this technique to be easily implemented in any laboratory.

Doshi H, Solli E, Elze T, Pasquale LR, Wall M, Kupersmith MJ. Unsupervised Machine Learning Identifies Quantifiable Patterns of Visual Field Loss in Idiopathic Intracranial Hypertension. Transl Vis Sci Technol 2021;10(9):37.Abstract
Purpose: Archetypal analysis, a form of unsupervised machine learning, identifies archetypal patterns within a visual field (VF) dataset such that any VF is described as a weighted sum of its archetypes (ATs) and has been used to quantify VF defects in glaucoma. We applied archetypal analysis to VFs affected by nonglaucomatous optic neuropathy caused by idiopathic intracranial hypertension (IIH). Methods: We created an AT model from 2862 VFs prospectively collected from 330 eyes in the IIH Treatment Trial (IIHTT). We compared baseline IIH AT patterns with their descriptive VF classifications from the IIHTT. Results: The optimum IIH AT model yielded 14 ATs resembling VF patterns reported in the IIHTT. Baseline VFs contained four or fewer meaningful ATs in 147 (89%) of study eyes. AT2 (mild general VF depression pattern) demonstrated the greatest number of study eyes with meaningful AT weight at baseline (n = 114), followed by AT1 (n = 91). Other ATs captured patterns of blind spot enlargement, hemianopia, arcuate, nasal defects, and more nonspecific patterns of general VF depression. Of all ATs, AT1 (normal pattern) had the strongest correlation with mean deviation (r = 0.69, P < 0.001). For 65 of the 93 VFs with a dominant AT, this AT matched the expert classification. Conclusions: Archetypal analysis identifies quantifiable, archetypal VF defects that resemble those commonly seen in IIH. Translational Relevance: Archetypal analysis provides a quantitative, objective method of measuring and monitoring disease-specific regional VF defects in IIH.
E J-Y, Mihailovic A, Garzon C, Schrack JA, Li T, West SK, Friedman DS, Gitlin LN, Ramulu PY. Importance and severity dependence of physical activity by GPS-tracked location in glaucoma patients: GPS-tracked physical activity in glaucoma. Am J Ophthalmol 2021;Abstract
PURPOSE: To quantify the association of visual field (VF) damage on physical activity away-from-home, per away-from-home excursion, and at home. DESIGN: Prospective cohort study. METHODS: Among 229 participants with glaucoma or suspected glaucoma, severity of VF damage was defined as average sensitivity within the integrated VF (IVF). Participants wore accelerometers and GPS trackers for seven days to measure physical activity and characterize activity location. Multivariable negative binomial regressions were used to test whether away-from-home activity per day, physical activity per away-from-home excursion, and at home activity per day varied by severity of VF damage. RESULTS: Each 5-dB decrement in IVF sensitivity was associated with a lower amount of away-from-home activities per day [18% less Moderate & Vigorous Physical Activity (MVPA) minutes/day, 95% CI, 0.69 to 0.97], and physical activities per away-from-home excursion (20% less MVPA minutes/excursion, 95% CI, 0.65, 0.98). Similar findings were noted for other away-from-home activity measures (including active minutes/steps per day, or active minutes/steps per excursion). However, worse IVF sensitivity was not associated with measures of at home activities (MVPA minutes/day, active minutes/day, and steps/day), time spent at or away from home, or excursions/week (p>0.1 for all). CONCLUSIONS: Restriction of physical activity in more severe glaucoma patients results mostly from activity restriction outside home environment. These findings highlight the importance of maintaining a safe home environment (where activity is less restricted) and increasing confidence to perform activity, particular high intensity activity, when leaving the home amongst patients with glaucoma.
E J-Y, Schrack JA, Mihailovic A, Wanigatunga AA, West SK, Friedman DS, Gitlin LN, Li T, Ramulu PY. Patterns of Daily Physical Activity across the Spectrum of Visual Field Damage in Glaucoma Patients. Ophthalmology 2021;128(1):70-77.Abstract
PURPOSE: To define and quantify patterns of objectively measured daily physical activity by level of visual field (VF) damage in glaucoma patients including: (1) activity fragmentation, a metric of health and physiologic decline, and (2) diurnal patterns of activity, a measure of rest and activity rhythms. DESIGN: Prospective cohort study. PARTICIPANTS: Older adults diagnosed with glaucoma or suspected glaucoma. METHODS: Degree of VF damage was defined by the average VF sensitivity within the integrated VF (IVF). Each participant wore a hip accelerometer for 1 week to measure daily minute-by-minute activity for 7 consecutive days. Activity fragmentation was calculated as the reciprocal of the average activity bout duration in minutes, with higher fragmentation indicating more transient, rather than sustained, activity. Multivariate linear regression was used to test for cross-sectional associations between VF damage and activity fragmentation. Multivariate linear mixed-effects models were used to assess the associations between VF damage and accumulation of activity across 6 3-hour intervals from 5 am to 11 pm. MAIN OUTCOME MEASURES: Activity fragmentation and amount of activity (steps) over the course of the day. RESULTS: Each 5-dB decrement in IVF sensitivity was associated with 16.3 fewer active minutes/day (P < 0.05) and 2% higher activity fragmentation (P < 0.05), but not with the number of active bouts per day (P = 0.30). In time-of-day analyses, lower IVF sensitivity was associated with fewer steps over the 11 am to 2 pm, 2 pm to 5 pm, and 5 pm to 8 pm periods (106.6, 93.1, and 89.2 fewer steps, respectively; P < 0.05 for all), but not over other periods. The activity midpoint (the time at which half of the daily activity is completed) did not vary across level of VF damage. CONCLUSIONS: At worse levels of VF damage, glaucoma patients demonstrate shorter, more fragmented bouts of physical activity throughout the day and lower activity levels during typical waking hours, reflecting low physiologic functioning. Further work is needed to establish the temporality of this association and whether glaucoma patients with such activity patterns are at a greater risk of adverse health outcomes associated with activity fragmentation.
E J-Y, Mihailovic A, Kuo P-L, West SK, Friedman DS, Gitlin LN, Li T, Schrack JA, Ramulu PY. Characterizing the Impact of Fear of Falling on Activity and Falls in Older Adults with Glaucoma. J Am Geriatr Soc 2020;68(8):1847-1851.Abstract
OBJECTIVE: Fear of falling (FoF) may alter mobility in older adults, especially among those with visual impairment. Using a longitudinal prospective cohort of older glaucoma patients, we investigated whether and how FoF is associated with future falls and physical activity. DESIGN: Prospective observational cohort study. SETTING: Hospital-based single-center recruitment. PARTICIPANTS: Individuals with glaucoma or suspected glaucoma. MEASUREMENTS: FoF was measured annually over a 3-year period using the University of Illinois at Chicago FoF Questionnaire, with lower Rasch-analyzed FoF scores (in logit units) indicating less fear. Participants recorded falls prospectively over the 3-year period using monthly mail-in calendars. Daily steps were collected annually over 7 days using an accelerometer. Visual field (VF) sensitivity was derived by combining sensitivities from monocular VF results. Participants completed questionnaires to determine other demographic/health characteristics. Multivariate random effects models evaluated within-participant changes in fall rates and physical activity across study years. RESULTS: At lower FoF levels (FoF≤0), each one-unit worsening in FoF score across study years was associated with 2.73 times higher odds of reporting at least one fall in the next year (95% confidence interval [CI] = 1.55-4.81) but was not associated with average daily steps (P = .44). Similar results were seen when fall rates were normalized by number of steps taken (P = .97). At higher FoF levels (FoF > 0), inter-year changes in FoF scores were not significantly associated with reporting a fall in the following year (P = .78) but were associated with 407 fewer average daily steps per one-unit change in FoF (95% CI = -743 to -71). CONCLUSION: FoF is an important psychological factor associated with mobility in glaucoma patients, although specific aspects of mobility (fall rates vs activity levels) affected vary by the degree of FoF. Our findings suggest that customizing behavioral interventions for older adults based on their levels of FoF may be an important strategy for fall prevention and activity promotion. J Am Geriatr Soc 68:1847-1851, 2020.
E J-Y, Mihailovic A, Schrack JA, Li T, Friedman DS, West SK, Gitlin LN, Ramulu PY. Characterizing Longitudinal Changes in Physical Activity and Fear of Falling after Falls in Glaucoma. J Am Geriatr Soc 2021;69(5):1249-1256.Abstract
BACKGROUND: Older adults with visual impairments experience a higher risk of falling, and are more vulnerable to adverse health consequences associated with falls than those with normal vision. This study characterizes longitudinal changes in objectively measured physical activity and fear of falling (FoF) occurring after various types of falls in visually impaired older adults. DESIGN: Prospective cohort study. SETTING: Hospital-based enrollment. PARTICIPANTS: People with glaucoma or suspected glaucoma. MEASUREMENTS: Falls were defined as unintentionally coming to rest on the ground or a lower level, and injurious falls were determined though follow-up calls. Study participants were categorized into three groups-fallers with injurious consequences, fallers without injurious consequences, and non-fallers based on fall status in the first year. Physical activity was assessed by waist-bound accelerometer. FoF was evaluated by questionnaire, with Rasch modeling generating FoF scores where higher scores reflected worse FoF. The 3-year longitudinal changes of physical activity and FoF were modeled using mixed-effects models. RESULTS: In linear models fully adjusted for visual field damage and other covariates, physical activity among injurious fallers showed greater annual (per year) declines in daily steps (-425 steps/d, 95% confidence interval (CI) = -793, -57), daily active minutes (-13 min/d, 95% CI = -21, -6), and daily moderate and vigorous physical activity (MVPA) minutes (-3 MVPA minutes/d, 95% CI = -5, 0) over the 3-year period as compared to non-fallers; however, physical activity did not significantly decline among non-injurious fallers. No longitudinal increases in FoF scores were observed in injurious or non-injurious fallers when compared to non-fallers. CONCLUSION: Among visually impaired older adults, injurious falls identified prospectively over 12 months contributed to a significant decline in physical activity over a 3-year period, while minimal changes were observed in FoF.
E J-Y, Mihailovic A, Garzon C, Schrack JA, Li T, West SK, Gitlin LN, Friedman DS, Ramulu PY. Association Between Visual Field Damage and Gait Dysfunction in Patients With Glaucoma. JAMA Ophthalmol 2021;Abstract
Importance: Gait dysfunction is common in older people with visual impairment and is a major cause of falls. Objective: To compare 3-year longitudinal changes in gait measures across the spectrum of baseline visual field (VF) damage in glaucoma. Design, Setting, and Participants: A post hoc analysis was designed on September 1, 2018, following a prospective cohort study, which enrolled older adults with glaucoma or suspected glaucoma from September 2013 to March 2015 and followed up for up to 3 years. Baseline VF damage was defined by integrated VF (IVF) sensitivity and categorized as normal/mild (IVF >28 dB), moderate (IVF, 23-28 dB), and severe (IVF, <23 dB). Each participant walked on an electronic walkway back and forth twice at normal pace each study year. Linear mixed-effects models evaluated longitudinal change in gait outcomes (1) stratified within each VF severity category and (2) across the range of IVF sensitivity. Analysis took place from October 2019 to October 2020. Main Outcomes and Measures: Three-year changes in 7 gait assessments under usual-pace walking, including base support and its coefficient of variation, stride length and its coefficient of variation, stride velocity and its coefficient of variation, and cadence. Results: Of 241 participants, the mean (SD) age was 70.8 (7.7) years, 116 (48.2%) were women, and 70 (29.0%) were African American. When comparing longitudinal gait changes over 3 years across the spectrum of IVF sensitivity, each 5-unit (dB) decrement was associated with more rapid declines in stride velocity (-0.05 z score unit/y; 95% CI, -0.09 to -0.01; P = .01) and cadence (-0.07 z score unit/y; 95% CI, -0.10 to -0.03; P < .001). When evaluating gait changes within each glaucoma severity group, shorter stride length was associated with persons with normal/mild (-0.06 z score unit/y; 95% CI, -0.10 to -0.03; P = .001), moderate (-0.08 z score unit/y; 95% CI, -0.12 to -0.04; P < .001), and severe VF damage (-0.16 z score unit/y; 95% CI, -0.24 to -0.07; P < .001), while stride velocity (-0.18 z score unit; 95% CI, -0.28 to -0.07; P = .002) and slower cadence (-0.15 z score unit; 95% CI, -0.25 to -0.04; P = .006) were associated with those with severe VF damage. Conclusions and Relevance: At worse levels of baseline VF damage, patients with glaucoma in this study demonstrated an exacerbated decline in walking speeds (ie, stride velocity and cadence), indicating that mobility speeds decrease faster over time in older adults with glaucoma.
Elhusseiny AM, Jamerson EC, Menshawey R, Tam EK, El Sayed YM. Collector Channels: Role and Evaluation in Schlemm's Canal Surgery. Curr Eye Res 2020;45(10):1181-1187.Abstract
OBJECTIVES: 1) To elucidate the role of collector channels in the aqueous humor outflow pathway 2) To suggest anatomic and functional methods of imaging collector channels in-vitro and in-vivo and 3) To discuss the role of such imaging modalities in the surgical management of glaucoma. METHODS: A thorough literature search was conducted on databases for studies published in English regarding the available methods to determine the role of collecting channels in normal and glaucomatous patients and to assess their patency. RESULTS: Intraocular pressure (IOP) exists as a balance between aqueous humor production and aqueous humor outflow. Collector channels are an essential anatomical constituent of the distal portion of the conventional aqueous humor outflow pathway. There are different surgical options for glaucoma management and with the recent advances in Schlemm's canal-based surgeries, collector channel's patency became a key factor in determining the optimum management for the glaucomatous eye. The advent of anatomic imaging methods has improved the ability to visualize collector channel morphology in-vitro, including swept-source optical coherence tomography (SS-OCT), spectral domain optical coherence tomography (SD-OCT), micro-computed tomography (micro CT), new immunohistochemistry techniques and scanning electron microscopy. The recent advent of real-time assessment of collector channel patency (including evaluation of episcleral venous outflow, observation of episcleral venous fluid wave, and tracer studies utilizing fluorescein, indocyanine green, and trypan blue) has been validated by the aforementioned anatomic imaging modalities. CONCLUSIONS: New modalities of in-vitro and in-vivo studies of collector channels provide promise to aid in the assessment of collector channel patency and individualization of surgical management for glaucoma patients.
Elhusseiny AM, VanderVeen DK. Early Experience With Ahmed Clear Path Glaucoma Drainage Device in Childhood Glaucoma. J Glaucoma 2021;30(7):575-578.Abstract
PURPOSE: The aim was to evaluate the short-term outcomes of Ahmed clear path (ACP) valveless glaucoma drainage device in childhood glaucoma. METHODS: Retrospective chart review of all patients 16 years or below with childhood glaucoma who had ACP implantation at Boston Children's Hospital from December 2019 to June 2020 with at least 6 months follow-up period. RESULTS: The study included 7 eyes of 5 patients implanted by a single surgeon. The median follow-up was 12 months. The mean intraocular pressure (IOP) was reduced from 36±3.5 mm Hg on a mean of 2.7±0.6 glaucoma medications preoperatively to a mean IOP of 12.4±2.8 mm Hg (P<0.001) on a mean of 0.7±0.8 medications postoperatively at final follow-up (P=0.0009). Complete success was achieved in 4 eyes while qualified success was achieved in 3 eyes. CONCLUSION: The ACP glaucoma drainage device provided good short-term IOP control and technical advantages for implantation for pediatric eyes were observed.
Elhusseiny AM, VanderVeen DK. Optical coherence tomography in the setting of optic nerve head cupping reversal in secondary childhood glaucoma. J AAPOS 2021;Abstract
Reversal of optic nerve head (ONH) cupping has been considered an important clinical observation that signals surgical success and control of intraocular pressure (IOP) in childhood glaucoma. Many theories based on elasticity of pediatric eyes have been proposed, including anterior movement of the elastic lamina cribrosa or shrinkage of the scleral canal. The relationship between these factors and axonal loss is unclear when reversal of cupping has been observed. Retinal nerve fiber layer (RNFL) optical coherence tomography (OCT) can help to clarify this. We present a case series of 4 pediatric patients with secondary glaucoma that demonstrated ONH cupping reversal with pre- and postoperative clinical images and RNFL OCT.
Elhusseiny AM, VanderVeen DK. Outcomes of Glaucoma Drainage Devices in Childhood Glaucoma. Semin Ophthalmol 2020;:1-11.Abstract
PURPOSE: Angle surgery is the gold standard for the management of many types of childhood glaucoma, yet glaucoma drainage devices (GDD) are effective tools for refractory advanced cases or secondary childhood glaucomas. The purpose of this article is to review recently published literature focused on the use of GDDs for pediatric glaucoma, including GDD general principles and surgical outcomes. METHODS: Literature review of various electronic databases was performed. RESULTS: 71 papers were reviewed for outcomes of GDD in childhood glaucomas. Success rates were usually defined by intraocular pressure (IOP) of 5-22 mmHg, with or without medications. Success rates were typically higher for non-valved GDDs but varied by length of follow-up. Non-valved GDDs afford lower and longer-lasting IOP control in pediatric eyes than valved GDD, however, no randomized controlled trials exist in childhood glaucoma. CONCLUSION: Various designs of GDDs are available for management of childhood glaucoma with good short-term success rates; individual patient factors should be taken into consideration when selecting a specific device.
Fan KC, Tsikata E, Khoueir Z, Simavli H, Guo R, A de Luna R, Pandit S, Que CJ, de Boer JF, Chen TC. Enhanced Diagnostic Capability for Glaucoma of 3-Dimensional Versus 2-Dimensional Neuroretinal Rim Parameters Using Spectral Domain Optical Coherence Tomography. J Glaucoma 2017;26(5):450-458.Abstract
PURPOSE: To compare the diagnostic capability of 3-dimensional (3D) neuroretinal rim parameters with existing 2-dimensional (2D) neuroretinal and retinal nerve fiber layer (RNFL) thickness rim parameters using spectral domain optical coherence tomography (SD-OCT) volume scans. MATERIALS AND METHODS: Design: Institutional prospective pilot study. STUDY POPULATION: 65 subjects (35 open-angle glaucoma patients, 30 normal patients). OBSERVATION PROCEDURES: One eye of each subject was included. SD-OCT was used to obtain 2D RNFL thickness values and 5 neuroretinal rim parameters [ie, 3D minimum distance band (MDB) thickness, 3D Bruch's membrane opening-minimum rim width (BMO-MRW), 3D rim volume, 2D rim area, and 2D rim thickness]. MAIN OUTCOME MEASURES: Area under the receiver operating characteristic curve values, sensitivity, and specificity. RESULTS: Comparing all 3D with all 2D parameters, 3D rim parameters (MDB, BMO-MRW, rim volume) generally had higher area under the receiver operating characteristic curve values (range, 0.770 to 0.946) compared with 2D parameters (RNFL thickness, rim area, rim thickness; range, 0.678 to 0.911). For global region analyses, all 3D rim parameters (BMO-MRW, rim volume, MDB) were equal to or better than 2D parameters (RNFL thickness, rim area, rim thickness; P-values from 0.023 to 1.0). Among the three 3D rim parameters (MDB, BMO-MRW, and rim volume), there were no significant differences in diagnostic capability (false discovery rate >0.05 at 95% specificity). CONCLUSIONS: 3D neuroretinal rim parameters (MDB, BMO-MRW, and rim volume) demonstrated better diagnostic capability for primary and secondary open-angle glaucomas compared with 2D neuroretinal parameters (rim area, rim thickness). Compared with 2D RNFL thickness, 3D neuroretinal rim parameters have the same or better diagnostic capability.
Fan BJ, Bailey JC, Igo RP, Kang JH, Boumenna T, Brilliant MH, Budenz DL, Fingert JH, Gaasterland T, Gaasterland D, Hauser MA, Kraft P, Lee RK, Lichter PR, Liu Y, Moroi SE, Myers JS, Pericak-Vance MA, Realini A, Rhee DJ, Richards JE, Ritch R, Schuman JS, Scott WK, Singh K, Sit AJ, Vollrath D, Weinreb RN, Wollstein G, Zack DJ, Haines JL, Pasquale LR, Wiggs JL. Association of a Primary Open-Angle Glaucoma Genetic Risk Score With Earlier Age at Diagnosis. JAMA Ophthalmol 2019;Abstract
Importance: Genetic variants associated with primary open-angle glaucoma (POAG) are known to influence disease risk. However, the clinical effect of associated variants individually or in aggregate is not known. Genetic risk scores (GRS) examine the cumulative genetic load by combining individual genetic variants into a single measure, which is assumed to have a larger effect and increased power to detect relevant disease-related associations. Objective: To investigate if a GRS that comprised 12 POAG genetic risk variants is associated with age at disease diagnosis. Design, Setting, and Participants: A cross-sectional study included individuals with POAG and controls from the Glaucoma Genes and Environment (GLAUGEN) study and the National Eye Institute Glaucoma Human Genetics Collaboration (NEIGHBOR) study. A GRS was formulated using 12 variants known to be associated with POAG, and the alleles associated with increasing risk of POAG were aligned in the case-control sets. In case-only analyses, the association of the GRS with age at diagnosis was analyzed as an estimate of disease onset. Results from cohort-specific analyses were combined with meta-analysis. Data collection started in August 2012 for the NEIGHBOR cohort and in July 2008 for the GLAUGEN cohort and were analyzed starting in March 2018. Main Outcomes and Measures: Association of a 12 single-nucleotide polymorphism POAG GRS with age at diagnosis in individuals with POAG using linear regression. Results: The GLAUGEN study included 976 individuals with POAG and 1140 controls. The NEIGHBOR study included 2132 individuals with POAG and 2290 controls. For individuals with POAG, the mean (SD) age at diagnosis was 63.6 (9.8) years in the GLAUGEN cohort and 66.0 (13.7) years in the NEIGHBOR cohort. For controls, the mean (SD) age at enrollment was 65.5 (9.2) years in the GLAUGEN cohort and 68.9 (11.4) years in the NEIGHBOR cohort. All study participants were European white. The GRS was strongly associated with POAG risk in case-control analysis (odds ratio per 1-point increase in score = 1.24; 95% CI, 1.21-1.27; P = 3.4 × 10-66). In case-only analyses, each higher GRS unit was associated with a 0.36-year earlier age at diagnosis (β = -0.36; 95% CI, -0.56 to -0.16; P = 4.0 × 10-4). Individuals in the top 5% of the GRS had a mean (SD) age at diagnosis of 5.2 (12.8) years earlier than those in the bottom 5% GRS (61.4 [12.7] vs 66.6 [12.9] years; P = 5.0 × 10-4). Conclusions and Relevance: A higher dose of POAG risk alleles was associated with an earlier age at glaucoma diagnosis. On average, individuals with POAG with the highest GRS had 5.2-year earlier age at diagnosis of disease. These results suggest that a GRS that comprised genetic variants associated with POAG could help identify patients with risk of earlier disease onset impacting screening and therapeutic strategies.
Fan BJ, Pasquale LR, Kang JH, Levkovitch-Verbin H, Haines JL, Wiggs JL. Association of clusterin (CLU) variants and exfoliation syndrome: An analysis in two Caucasian studies and a meta-analysis. Exp Eye Res 2015;139:115-22.Abstract

Exfoliation syndrome (XFS) is an important risk factor for glaucoma (XFG) worldwide. LOXL1 variants are highly associated with XFS in most populations; however, the high frequency of risk alleles in normal individuals and the reversal of risk alleles in different ethnic populations suggest that other factors contribute to XFS pathogenesis. Clusterin (CLU) is an extracellular matrix chaperone that prevents protein aggregation and is highly expressed in ocular tissues affected by XFS. Studies examining common CLU variants for association with XFS have been inconsistent. The purpose of this study was to evaluate CLU variants for association with XFS in two independent datasets from the United States (222 cases and 344 controls) and Israel (92 cases and 102 controls). Seven tag SNPs that captured >95% of alleles at r(2) greater than 0.8 across the CLU genomic region were genotyped using TaqMan assays. Genotypes for an additional SNP, rs2279590, were imputed using phased haplotypes of HapMap reference CEU samples. Of the 8 CLU SNPs selected for the study, none were significantly associated with XFS in either case-control group (age and sex adjusted P > 0.14 and 0.36, respectively, in the US and Israeli datasets), or when they were meta-analyzed together (age and sex adjusted P > 0.13). Haplotype analysis using all 8 SNPs or only the promoter region SNPs also did not show significant associations of CLU with XFS in the combined US and Israeli dataset (P > 0.28). Meta-analysis of the data from this study and previous studies in Caucasian populations (1184 cases and 978 controls) resulted in statistically significant association of rs2279590 with XFS (summary OR = 1.18, 95% CI: 1.03-1.33, P = 0.01). Significant association between rs2279590 and XFS was also found in Indian populations (summary OR = 0.76, 95% CI: 0.61-0.96; P = 0.02); however, significant heterogeneity between the Caucasian and Indian populations possibly due to reversal of the risk allele precluded an overall meta-analysis for rs2279590 (Q = 0.001, I(2) = 91%). No significant association was identified for rs3087554 in either Caucasian populations (summary OR = 0.90, 95% CI: 0.77-1.05, P = 0.17) or Indian populations (summary OR = 0.89, 95% CI: 0.72-1.10, P = 0.28), or in both populations combined (1705 cases and 3713 controls; summary OR = 0.90, 95% CI: 0.79-1.01, P = 0.08). Significant heterogeneity precluded the addition of the Japanese data to the meta-analysis for rs3087554 (Q = 0.006, I(2) = 87%). Our results suggest that common CLU variants may contribute to modest XFS risk but even larger datasets are required to confirm these findings.

Feinstein M, Moussa K, Han Y. Ab Interno Tube Occlusion for Postoperative Hypotony in a Patient With an Ahmed Glaucoma Drainage Device. J Glaucoma 2018;27(3):e61-e63.Abstract
PURPOSE: To report a case of Ahmed glaucoma valve-induced hypotony that was successfully managed with postoperative intraluminal stenting of the aqueous shunt tube. PATIENT AND METHODS: We describe a 68-year-old man with advanced uveitic glaucoma with an intraocular pressure (IOP) of 25 mm Hg in the left eye. The patient initially responded well to an Ahmed glaucoma valve implant, but at 10 weeks postimplantation, the patient underwent cataract surgery and developed persistent hypotony, choroidal folds, and decreased vision. RESULTS: Before partial occlusion of the aqueous shunt tube, the patient had an IOP of 3 mm Hg and a best-corrected visual acuity (BCVA) of 20/60. Following intraluminal stenting of the aqueous shunt tube with 4-0 polypropylene suture (Prolene; Ethican), IOP rose from 7 to 10 mm Hg, BCVA improved to 20/30, and the choroidal folds resolved; IOP and BCVA remained stable through 1 year of follow-up and no additional surgical or pharmacological interventions were required. CONCLUSIONS: Aqueous shunt-induced hypotony can be successfully managed with intraluminal stenting and should be considered before tubal ligation or shunt removal.
Feke GT, Rhee DJ, Turalba AV, Pasquale LR. Effects of dorzolamide-timolol and brimonidine-timolol on retinal vascular autoregulation and ocular perfusion pressure in primary open angle glaucoma. J Ocul Pharmacol Ther 2013;29(7):639-45.Abstract
PURPOSE: To assess whether dorzolamide 2%-timolol 0.5% (D/T) and/or brimonidine 0.2%-timolol 0.5% (B/T) alters retinal vascular autoregulation (RVA) and seated ocular perfusion pressure (sOPP) in primary open angle glaucoma (POAG) patients who demonstrate retinal vascular dysregulation (RVD) on timolol 0.5% alone. METHODS: In this prospective, observer-masked, crossover study, 21 POAG patients with untreated intraocular pressure (IOP) >21 mmHg were treated for 6 weeks with timolol 0.5%. Subsequently, we measured inferior temporal retinal artery blood flow in the left eye with subjects seated and then while reclined for 30 min using the Canon Laser Blood Flowmeter. Subjects with a change in retinal blood flow in response to posture change outside of the range previously found in healthy subjects were designated as having RVD and randomized to either D/T or B/T for 6 weeks and re-tested. This was followed by treatment with the opposite medication. RESULTS: Seven of the 21 subjects demonstrated RVD in response to posture change following timolol 0.5%. Multiple linear regression analysis indicated that lower sOPP was the main determinant of RVD (P=0.033). After treatment with D/T, all 7 converted from RVD to normal RVA status (P=0.001). Four of 6 subjects showed a similar return to normal RVA following B/T (P=0.066). Mid-morning sOPP was 41.1±5.5 mmHg post-timolol, 46.3±6.5 mmHg post-D/T, and 38.6±6.0 mmHg post-B/T (D/T vs. B/T, P=0.026). CONCLUSIONS: D/T significantly improved RVA in POAG patients exhibiting RVD while on timolol 0.5% alone. D/T also increased sOPP compared to B/T. There was no significant difference (P=0.37) between D/T and B/T in improving RVA.
Feke GT, Bex PJ, Taylor CP, Rhee DJ, Turalba AV, Chen TC, Wand M, Pasquale LR. Effect of brimonidine on retinal vascular autoregulation and short-term visual function in normal tension glaucoma. Am J Ophthalmol 2014;158(1):105-112.e1.Abstract

PURPOSE: To assess whether brimonidine 0.15% alters retinal vascular autoregulation and short-term visual function in normal tension glaucoma patients who demonstrate retinal vascular dysregulation. DESIGN: Nonrandomized clinical trial. METHODS: In this prospective study, 46 normal tension glaucoma patients not previously treated with brimonidine underwent retinal vascular autoregulation testing and visual function assessment using frequency doubling technology perimetry and equivalent noise motion sensitivity testing. We measured blood flow in a major temporal retinal artery with subjects seated and then while reclined for 30 minutes. Patients having a change in retinal blood flow with posture change outside the range previously found in healthy subjects were classified as having retinal vascular dysregulation. They were treated with brimonidine 0.15% for 8 weeks and designated for retesting. RESULTS: Twenty-three patients demonstrated retinal vascular dysregulation at the initial visit. Younger age (P = .050) and diabetes (P = .055) were marginally significant risk factors for retinal vascular dysregulation. After the 8-week course with brimonidine, 14 of the 17 patients who completed the study showed a return of posture-induced retinal blood flow changes to levels consistent with normal retinal vascular autoregulation (P < .0001). We found no significant changes in frequency doubling technology perimetry or in motion detection parameters following treatment with brimondine (P > .09 for all tests performed). CONCLUSIONS: Brimonidine significantly improved impaired retinal vascular autoregulation in normal tension glaucoma patients, but short-term alteration in visual function could not be demonstrated.