Choroidal thickness measurements in young Saudi adult population: a cross-sectional study.

AIM: To determine the choroidal thickness (CT) in young healthy Saudi adults using spectral-domain optical coherence tomography (SD-OCT) with an automated CT segmentation software. METHODS: Fifty-eight young adults (total of 116 eyes), 39 males and 19 females participated in this study between the ages of 18 and 38y (mean 22.65±3.9y). All participants underwent ophthalmic screening examination, including the SD-OCT for measurements of CT in each quadrant egmented into five eccentric regions starting from the foveal region up to 4.5 mm towards the periphery. RESULTS: The choroid was thickest in the foveal region (central 1 mm, 300±60 µm) and began to progressively thinner beyond the parafovea (1.5-2.5 mm, 284±67 µm) towards the peripheral region (3.5-4.5 mm from the fovea, 254±83 µm). The superior choroid showed the thickest profile (309±57 µm), while the nasal choroid exhibited the thinnest (229±76 µm). The rate of the thinning with increasing eccentricity was more predominant in the nasal choroid, which thinned from the foveal region (294±58 µm) to the peripheral region (158±55 µm). The superior and inferior choroid did not show a statistically significant thinning with eccentricity (all P>0.05). There was no statistically significant difference in the CT between gender, age, and laterality of the eyes (all P>0.05). A significant association of myopia with thinner subfoveal choroid was observed (Pearson's, r=0.37), and regression analysis showed that a 10.3 µm choroidal thinning for each diopter increase of myopia. CONCLUSION: CT profile depends on eccentric and the quadrant. The CT profile across the measured area in the young Saudi adult population is comparable to other previous reports. Refractive error is critical for CT evaluation.

Can older adults' balance and mobility improve with visual attention training?

PURPOSE: We hypothesize that training older adults with a structured visual attention task will result in improved balance and mobility, potentially reducing their risk for falls. METHODS: Healthy older adults aged 70 + took part in the study (mean age 80.3 ± 6 years). In this randomised control trial (NCT02030743), 15 participants were randomly assigned to a visual attention training group and 15 to a control group. Visual attention training was undertaken twice a week (45 min sessions) for 3 weeks (= six sessions) using versions of a selective attention useful field of view test and attended field of view test. The outcome measures were postural sway using a force plate, the Mini-Balance Evaluation Systems Test, the One-Legged Stance test, the 5 Meter Walking test, the Sit to Stand test, the Timed Up and Go test without and with a concurrent cognitive task. RESULTS: There was a greater improvement in visual attention after training in the intervention group compared to the control group (p < 0.01). However, a mixed ANOVA (2× groups, 2× visit) showed no main effect of visit or group or any interaction for any of the force plate parameters. T tests of the changes over time between the intervention group and the control groups for the other balance and mobility assessment tools showed no improvement after the visual attention training. CONCLUSION: It was found that there was no improvement in either mobility or balance after the visual attention training and no difference between the intervention and the control groups.

Binocular Vision Disorders and Visual Attention: Associations With Balance and Mobility in Older Adults.

Understanding which aspects of vision are related to falls is important. We examine the associations between tests of balance, mobility, fear of falling (FES-1) and aspects of vision in 72 adults aged 70+. Balance and mobility were examined using the One Legged Stance test (OLST), the Sit to Stand test (STST) and the 5 Meter Walking test (5MWT). Visual measures included visual acuity (VA), contrast sensitivity, stereoacuity, binocular vision (BV) measurements, Useful field of View (UFV) and Attended Field of View (AFOV). Reduced performance on the OLST and the STST was significantly correlated with abnormal BV and poorer intermediate VA. Poorer function on the 5MWT and the FES-I was also predicted by poor intermediate VA and poorer performance on the OLST, STST and the 5MWT was associated with UFV errors. The results are of high importance as many BV disorders are treatable and visual attention is trainable.