Navigated perilesional transcranial magnetic stimulation can improve post-stroke visual field defect: A double-blind sham-controlled study

Background: Visual field defects (VFD) usually do not show improvement beyond 12 weeks from their onset. It has been shown that repetitive presentation of a stimulus to areas of residual vision in cases of visual field defect can improve vision. The counterpart of these areas in the brain are the partially damaged brain regions at the perilesional areas where plasticity can be enhanced. Objective: We aimed to study the effect of navigated repetitive transcranial magnetic stimulation (rTMS) applied to perilesional areas on the recovery of patients with cortical VFD. Methods: Thirty-two patients with cortical VFD secondary to stroke of more than 3 months duration received 16 sessions of either active or sham high frequency navigated perilesional rTMS. Automated perimetry and visual functioning questionnaire (VFQ-25) were performed at baseline and after completion of the sessions. Results: The active group showed significant improvement after intervention, compared to the sham group, in both mean deviation (MD), visual field index (VFI) and in the VFQ-25 scores. Conclusions: Navigated rTMS is a new treatment option for post-stroke VFD as it can selectively stimulate areas of residual vision around the infarcted tissue, improving the threshold of visual stimulus detection which could be used alone or in combination with existing therapies.

Visual Cortex Transcranial Direct Current Stimulation for Proliferative Diabetic Retinopathy Patients: A Double-Blinded Randomized Exploratory Trial

Proliferative diabetic retinopathy (PDR) is a severe complication of diabetes. PDR-related retinal hemorrhages often lead to severe vision loss. The main goals of management are to prevent visual impairment progression and improve residual vision. We explored the potential of transcranial direct current stimulation (tDCS) to enhance residual vision. tDCS applied to the primary visual cortex (V1) may improve visual input processing from PDR patients’ retinas. Eleven PDR patients received cathodal tDCS stimulation of V1 (1 mA for 10 min), and another eleven patients received sham stimulation (1 mA for 30 s). Visual acuity (logarithm of the minimum angle of resolution (LogMAR) scores) and number acuity (reaction times (RTs) and accuracy rates (ARs)) were measured before and immediately after stimulation. The LogMAR scores and the RTs of patients who received cathodal tDCS decreased significantly after stimulation. Cathodal tDCS has no significant effect on ARs. There were no significant changes in the LogMAR scores, RTs, and ARs of PDR patients who received sham stimulation. The results are compatible with our proposal that neuronal noise aggravates impaired visual function in PDR. The therapeutic effect indicates the potential of tDCS as a safe and effective vision rehabilitation tool for PDR patients.

Clinical Outcomes of Use of Low Vision Aids for Enhancement of Residual Vision in Diabetic Retinopathy

Purpose: To investigate clinical outcomes of use of low vision aids for enhancement of residual vision in people with Diabetic Retinopathy (DR). Study Design: Cross-sectional study. Place and Duration of Study: Hayatabad Medical Complex Peshawar, from January 2018 to December 2019. Methods: Eighty-one consecutive patients with DR were assessed in a low vision clinic for vision rehabilitation. Data regarding distance and near visual acuity (VA), refractive error, types of low vision aids (LVAs), VA with best correction and with LVAs were collected and analyzed. Results: A total of 81 people with DR, 63% were male. Mean age was 58.48 ± 13.54 years. With mean duration of 12.6 years of diabetes, 29.6% had Insulin dependent while 70.4% had non-Insulin dependent diabetes. At presentation, 63% had moderate vision impairment (0.5 > VA > 1.0), 14.8% had severe vision impairment (1.0 > VA > 1.3) and 22.2% had blindness (VA < 1.3).With LVAs, 97.5% achieved distance VA of Log MAR 0.4 or better. Mean improvement in distance VA with LVAs was Log MAR 0.95 ± 0.19 (P = 0.000; 95% CI). Near VA improved significantly with LVAs and the number of participants who could see 1M or better with their own glasses increased from 7.4% to 97.5% (p < 0.001). Binocular telescopes 2.1X were the most preferred low vision device for distance vision and prismatic magnifying spectacles for near vision. Conclusion: Visual rehabilitation through the use of LVAs was helpful in patients with low vision caused by diabetic retinopathy. Hence, improving the quality of life. Key Words: Diabetic retinopathy, blindness, visual rehabilitation, low vision aids, Pakistan.

Teaching Braille Literacy To Blind Primary Schoolchildren And Those With Residual Vision

Nowadays one of the main issues of pedagogy is teaching to primary school children who are blind and those with residual vision. Among those schoolchildren writing disorders are quite common and have a negative effect on their learning progress. The quality and acquisition of school curriculum slows down, and in general negatively affects the learning process of these children. The relevance of the study depends on the fact that sufficient methods, approaches related to teaching Braille literacy have not yet been thoroughly studied and developed.There are insufficient typhlotechnical, typhographic techniques to help promote literacy through the Braille system. The study of the above-mentioned and other similar issues will help to fully implement the Braille system thus improving the writing abilities of children with visual impairments.

Outcome of Endoscopic Optic Nerve Decompression for Traumatic Optic Neuropathy

Objective: This study aimed to evaluate the outcomes of endoscopic optic nerve decompression (EOND) for adults with traumatic optic neuropathy (TON) and seek factors that might affect surgery outcomes. Methods: From January 2016 to June 2019, 16 adults diagnosed with TON, who underwent endoscopic trans-ethmosphenoid optic canal decompression, were reviewed. All the patients were treated with steroids before the surgery. The main outcome measure was an improvement in visual acuity (VA) after treatment. Results: Eight (50.0%) patients had residual vision before the surgery, while eight (50.0%) had no light perception. After surgical decompression, partial recovery of VA was achieved in three (18.75%) patients who were operated within 10 days and had residual vision before the surgery. However, no improvement in VA was observed for the remaining patients (81.25%) who were operated more than 10 days after injuries. Conclusions: EOND is beneficial for TON not responding to steroid therapy and can prevent permanent disability if earlier intervention is done prior to irreversible damage to the nerve. Endoscopic optic nerve surgery can decompress the traumatic and edematous optic nerve with proper exposure of optic canal and orbital apex without any major complications. The operation timing and residual vision are important factors affecting outcomes.

Augmented Reality for People with Low Vision: Symbolic and Alphanumeric Representation of Information

Many individuals with visual impairments have residual vision that often remains underused by assistive technologies. Head-mounted augmented reality (AR) devices can provide assistance, by recoding difficult-to-perceive information into a visual format that is more accessible. Here, we evaluate symbolic and alphanumeric information representations for their efficiency and usability in two prototypical AR applications: namely, recognizing facial expressions of conversational partners and reading the time. We find that while AR provides a general benefit, the complexity of the visual representations has to be matched to the user’s visual acuity.