Changes in visual acuity using low vision devices in patients with Leber hereditary optic neuropathy: A retrospective study.

Purpose: This study was conducted to estimate the visual acuity improvement in patients with Leber hereditary optic neuropathy (LHON) with the help of low vision devices (LVDs) and to analyze the types of distant and near LVDs prescribed to the patients with LHON. Methods: A retrospective case review of 74 subjects with LHON who were referred to a low vision care clinic at a tertiary eye center from 2016 to 2019 were recruited. The reason for referral was assessed from the patients' electronic medical records (EMR). Demographic data of the patients, visual acuity status, type of LVD prescribed, and visual acuity improvement with LVD were documented. Results: Out of 74 patients, 91.9% (n = 68) were male, and the median age of patients was 21 (16) years. A 4× monocular telescope was prescribed for 2.7% of patients (n = 2) and SEETV binocular telescope for 1.4% (n = 1) was advised for distance. The most commonly prescribed near LVD was the 6× cutaway stand magnifier for 22 patients (29.7%). Four patients (5.4%) were prescribed with Notex, the most commonly prescribed non-optical LVD. Niki CCTV (12.2%, n=9) was the most commonly prescribed assistive device. The subjects were divided into three groups based on age: group I consisted of those <18 years of age, group II 18-40 years, and group III >40 years for the interpretation of visual improvement. There was a statistically significant improvement (group I: P < 0.001, group II: P < 0.0001, group III: P < 0.003) in near vision with help of LVDs in all three groups. Conclusion: The use of LVDs and rehabilitation can help patients with LHON to lead a better life and will be more beneficial.

Use of augmented reality technology for improving visual acuity of individuals with low vision.

Purpose: The objective of this study was to analyze the visual acuity improvement in patients with low vision using augmented reality device who presented to the low vision care (LVC) clinic at a tertiary eye care center. Methods: A prospective study of 100 patients with low vision who were referred to the LVC clinic between July and December 2018 was done. Demographic data and visual acuity improvement assessed using augmented reality (AR) technology paired with Samsung Gear headset were documented. Results: Out of 100 patients, 74 were male and 26 were female. The median age of the overall patients was 36 (25.5) years. In 100 patients, 21% patients were found to have central field loss (CFL), 35% patients have peripheral field loss (PFL), and 44% patients were found to have overall blurred vision (OBV). Majority of the subjects with CFL (47%) and OBV (37%) has a moderate visual impairment and in PFL group (26%), severe visual impairment was more. Cone dystrophy (9%) was found to be the major cause of CFL group, retinitis pigmentosa (22%) in the case of PFL group, and optic atrophy (10%) in the case of OBV group. The median distance visual acuity 0.9 log MAR improved to 0.2 log MAR (P < 0.0001) and median near visual acuity 0.4 log MAR improved to 0.1 log MAR with a P value of < 0.0001 using AR device. Conclusion: The use of an AR device can help patients with low vision to improve their residual vision for better visual performance.