Ocular Media Properties and Short Wavelength Automated Perimetry

Abstract

Abstract: : Purpose: To identify ocular media properties influencing the increased between-subject normal variability of SWAP compared with conventional white-on-white (W-W) automated perimetry. Methods: One eye of 25 subjects (mean age=66.5 yrs; range 42-82) with varying degrees of media opacity (LOCS III mean 0.66, SD 0.92, range 0.0-4.0) was examined over three visits. At the initial visit, the Van den Berg straylight meter was used to obtain values for forward light scatter; disability glare was measured using the Brightness Acuity Tester (BAT) and the Early Treatment of Diabetic Retinopathy Study (ETDRS) chart at 96% and 10% contrast; 3 training visual field examinations were undertaken (2 SWAP, 1 W-W) using the Humphrey Field Analyzer 750, the results of which were discarded. The second visit consisted of ocular media absorption (OMA) measurement and 2 visual field examinations (1 SWAP, 1 W-W) utilising Program 24-2. The final visit involved lens assessment, using LOCS III and fundus examination after pupil dilation and IOP measurement. Results: Little relationship was found between SWAP Mean Sensitivity (MS), SWAP Mean Deviation (MD), and OMA (R²=0.023: R²=0.053); forward light scatter (R²=0.039: R² =0.006); disability glare at 96% contrast (R²=0.002: R² =0.0042) and at 10% contrast (R² =0.074: R² =0.008). The correlation between SWAP MS and age was markedly higher (R² =0.3146). Little correlation was present between W-W MS, W-W MD and OMA (R² =0.042: R² =0.001); disability glare at 96% contrast (R² =0.072:R² =0.096) and at 10% contrast (R² =0.051: R² =0.031). The relationships between W-W MS and age (R ²=0.4508) and straylight was stronger (R² = 0.3043). Conclusions: None of the measured ocular media properties were strongly associated with SWAP MS and therefore will not assist in the indentification of those individuals who have increased variability on SWAP.

Keywords: visual fields