Quantifying the impact on navigation performance in visually impaired: Auditory information loss versus information gain enabled through electronic travel aids.

This study's purpose was to analyze and quantify the impact of auditory information loss versus information gain provided by electronic travel aids (ETAs) on navigation performance in people with low vision. Navigation performance of ten subjects (age: 54.9±11.2 years) with visual acuities >1.0 LogMAR was assessed via the Graz Mobility Test (GMT). Subjects passed through a maze in three different modalities: 'Normal' with visual and auditory information available, 'Auditory Information Loss' with artificially reduced hearing (leaving only visual information), and 'ETA' with a vibrating ETA based on ultrasonic waves, thereby facilitating visual, auditory, and tactile information. Main performance measures comprised passage time and number of contacts. Additionally, head tracking was used to relate head movements to motion direction. When comparing 'Auditory Information Loss' to 'Normal', subjects needed significantly more time (p<0.001), made more contacts (p<0.001), had higher relative viewing angles (p = 0.002), and a higher percentage of orientation losses (p = 0.011). The only significant difference when comparing 'ETA' to 'Normal' was a reduced number of contacts (p<0.001). Our study provides objective, quantifiable measures of the impact of reduced hearing on the navigation performance in low vision subjects. Significant effects of 'Auditory Information Loss' were found for all measures; for example, passage time increased by 17.4%. These findings show that low vision subjects rely on auditory information for navigation. In contrast, the impact of the ETA was not significant but further analysis of head movements revealed two different coping strategies: half of the subjects used the ETA to increase speed, whereas the other half aimed at avoiding contacts.

CHANGE OF CHOROIDAL VOLUME IN UNTREATED CENTRAL SEROUS CHORIORETINOPATHY.

PURPOSE: Choroidal hyperpermeability plays a central role in the pathophysiology of central serous chorioretinopathy (CSC). In active CSC undergoing treatment, choroidal thickness decreases if subretinal fluid (SRF) resolves. This study aimed to investigate the change in choroidal thickness and volume in eyes with untreated CSC. METHODS: The authors retrospectively analyzed 27 eyes with treatment-naïve CSC (25 patients), who had a follow-up of 4 to 6 weeks. Retinal and choroidal volume and SRF were segmented manually and calculated using the Spectralis OCT built-in software (Spectralis; Heidelberg Engineering). RESULTS: In treatment-naïve eyes with CSC, an increase in SRF was significantly associated with an increase in choroidal thickness and volume (rho = 0.93, P < 0.01). Eyes with greater baseline choroidal volume showed a significantly greater decrease in SRF during follow-up (rho = -0.47, P = 0.03). CONCLUSION: In this study, an increase in SRF was associated with an increase in both choroidal thickness and volume in eyes with treatment-naïve CSC. Eyes with thicker baseline choroidal volume showed a greater reduction in SRF.

Assessment of vision-related quality of life in patients with central retinal artery occlusion.

BACKGROUND: Central retinal artery occlusion (CRAO) is a major cause for severe visual impairment. Its effect on vision-related quality of life has not yet been determined. The purpose of the present study was thus to assess vision-related quality of life in patients with CRAO using the 39-item National Eye Institute Visual Function Questionnaire. METHODS: The case-control study comprised 26 patients with unilateral CRAO and a control group consisting of 26 control subjects, matched for age and sex. Vision-related quality of life was measured using the 39-item National Eye Institute Visual Function Questionnaire. RESULTS: After Bonferroni correction, the median 39-item National Eye Institute Visual Function Questionnaire composite score was significantly lower in patients with CRAO than in those in the control group (P(corr) < 0.001). Patients with CRAO showed significantly lower median scores in 9 of 12 subscales: general vision (P(corr) < 0.001), peripheral vision (P(corr) < 0.001), difficulties with near-vision activities (P(corr) < 0.001), difficulties with distance-vision activities (P(corr) < 0.001), role difficulties as a result of vision problems (P(corr) < 0.001), dependency on others because of vision problems (P(corr) < 0.001), limitations in social functioning because of vision problems (P(corr) < 0.001), mental health symptoms because of vision problems (P(corr) < 0.001), and general health (P(corr) = 0.008). CONCLUSION: Our data suggest that vision-related quality of life is reduced in patients with CRAO.

Association of preoperative optical coherence tomography markers with residual inner limiting membrane in epiretinal membrane peeling.

PURPOSE: To identify preoperative markers on spectral domain optical coherence tomography (SD-OCT) for residual inner limiting membrane (ILM) in epiretinal membrane (ERM) peeling. METHODS: In this retrospective case series the preoperative SD-OCTs from 119 eyes of 119 consecutive patients who underwent surgery for idiopathic ERM by a single surgeon were evaluated for markers predisposing for ILM persistence after ERM removal. ILM persistence was determined via intraoperative indocyanine green staining. The main outcome measures were correlation of central foveal thickness (CFT), ERM thickness, extent of elevated ERM and retinal folding, intraretinal cysts, and discontinuation of the ERM, with ILM persistence after ERM peeling. RESULTS: The persistence of the ILM was found in 50.4% (n = 60). After Bonferroni correction for multiple testing, a greater extent of elevated ERM and thicker ERMs were associated with persistence of the ILM (p<0.005). The other parameters showed no statistically significant correlations with the persistence of the ILM (p≥0.005). CONCLUSION: Residual ILM can be found in nearly half of the eyes after ERM peeling. A loose connection between the ERM and the retinal surface predisposes for ILM persistence. Preoperative SD-OCT is helpful in identifying risk markers for the persistence of the ILM in ERM surgery.