Online circular contrast perimetry via a web-application: optimising parameters and establishing a normative database.

PURPOSE: To establish a normative database and optimise parameters for personal-computer based perimetry via a web-application using circular contrast targets. METHODS: Online 24-degree 52-loci perimetry was delivered through a web-application using circular flickering contrast targets. Embedding contrast differentials within targets allows calculation of relative decibel (rdB) per 256-bit greyscale level differential. Target light-band maximum brightness colour was fixed, while the dark-band varied to achieve the desired rdB level. A staircase system was used with two reversals ranging from 0 to 36 rdB levels. Blind spot localisation at the start of the test was used to optimise viewing distance and subsequently count fixation losses. Gaze was maintained on a spinning golden star which moves mid-test to maximise sampling area. Patients performed the test to each eye separately using a computer in a darkened room at 40-45 cm. RESULTS: 158 eyes of 101 patients completed the Online Circular Contrast Perimetry (OCCP) test. Mean age was 62.9 ± 14.3 years old. Mean sensitivity reduced with age, at 1.0 relative decibel per decade. Mean sensitivity per locus correlated with standard automated perimetry (SAP) in a physiological hill of vision, with an average difference of 4.02 decibels (95% confidence interval (CI) = 3.77-4.27, p < 0.001) and good agreement between tests. CONCLUSIONS: Online circular contract perimetry provides accurate perimetric testing with comparable results to standard automated perimetry.

Comparison of perimetric Glaucoma Staging Systems in Asians with primary glaucoma.

BACKGROUND: To compare functional staging classifications in Vietnamese patients with primary open angle glaucoma (POAG) and chronic primary angle closure glaucoma (PACG). METHODS: A retrospective cross-section study was conducted at a national setting. Two hundred seven eyes of 207 patients were recruited. Patients were tested with standard automated perimetry. Field loss was generally classified in four stages (normal, early, moderate, and severe), using four classification strategies: (1) Hodapp-Parrish-Anderson (HPA), (2) enhanced Glaucoma Staging System (eGSS), (3) modified Glaucoma Staging System (mGSS) and (4) the Advanced Glaucoma Intervention Study (AGIS). AGIS as a standard method was used to judge the staging performance of the other three classifications in terms of agreement (Cohen Kappa-K) and association (Chi-Square Test-Cramer's V). RESULTS: The agreement between AGIS and mGSS (K = 0.687; p < 0.001) and HPA (K = 0.686; p < 0.001) was substantial while that between AGIS and eGSS was slight (K = 0.103; p < 0.001). The association between AGIS and mGSS (V = 0.748; p < 0.001) and HPA (V = 0.748; p < 0.001) was greater than eGSS (V = 0.594; p < 0.001). CONCLUSIONS: MGSS and HPA showed stronger agreement and closer association with AGIS than eGSS. We recommend mGSS should be used in managing a glaucoma clinic because of its simplicity and convenience over HPA and AGIS.

The Computerized Glaucoma Visual Function Test: A Pilot Study Evaluating Computer-Screen Based Tests of Visual Function in Glaucoma.

Purpose: We aimed to develop and evaluate the Computerized Glaucoma Visual Function Test (CoGVFT), among a cohort of glaucoma patients, and identify potential new items to optimize the test. Method: A cross-sectional study involving 84 patients with open-angle glaucoma of varying severity and 18 controls without glaucoma were recruited. Better and worse eye visual field parameters, visual acuity, contrast sensitivity, 6-Part Cognitive Impairment Test (6CIT) and Glaucoma Activity Limitation-9 (GAL-9) questionnaire responses were recorded. The CoGVFT was administered to all participants. Rasch analysis was used to assess the psychometric properties of the CoGVFT, which was then evaluated with criterion, convergent, and divergent validity tests. Regression modeling determined factors predictive of CoGVFT performance. Results: The 38-item CoGVFT demonstrated convergent validity with statistically significant differences in glaucoma severity groups (P < 0.001, analysis of variance). The correlation coefficient for CoGVFT person measures (logits) with GAL-9 person measures (logits) and better eye (BE) mean deviation was 0.528 (P < 0.001) and 0.762 (P < 0.001), respectively, demonstrating convergent validity. Divergent validity was suboptimal as the 6CIT score demonstrated moderate correlation (r = 0.463, P < 0.001) with CoGVFT person measures (logits). Multivariable analysis revealed that better BE contrast sensitivity, lower age, and better BE visual acuity were associated with better CoGVFT performance (P < 0.001). Conclusions: The CoGVFT retains most of the features of its predecessor to estimate vision-based activity limitation related to glaucoma. Translational Relevance: The CoGVFT is an easily accessible tool that can potentially be used in the community to help detect undiagnosed glaucoma in the population.

Drug-induced Myopia and Bilateral Angle Closure Secondary to Zolmitriptan.

PURPOSE: To describe a unique case of drug-induced transient myopia with angle-closure glaucoma in a patient being treated with zolmitriptan for migraines. METHODS: A 42-year-old woman who had been using increasing amounts of zolmitriptan over the previous 12 months presented with an acute myopic shift and raised intraocular pressures (IOP) with anterior chamber shallowing. Clinical examination findings at presentation and at follow-up visits were reviewed. RESULTS: Initial examination revealed unaided visual acuities of 20/100 in the right eye and 20/125 in the left, with IOP measuring 34 mm Hg bilaterally. Zolmitriptan was ceased and the patient was commenced on topical antiglaucoma medication. Within 2 weeks, IOP had normalized, with deepening of the anterior chambers and complete resolution of her myopia. Her final recorded unaided visual acuities were 20/12.5 in the right eye and 20/16 in the left. When topical antiglaucoma medication was ceased the patient developed pressure-related headaches and selective laser trabeculoplasty was performed to minimize the need for long-term topical medication use. CONCLUSION: Idiosyncratic drug reactions resulting in ciliochoroidal effusion, secondary angle closure, and transient myopia are well described, but they have not been previously reported with zolmitriptan use. An awareness of the various potential causative agents is important, as findings are generally reversible if recognized early and if the offending drug is discontinued.