Abstract
Purpose :
Visual acuity recorded with photopic standard black letter charts or contrasted sinusoidal gratings previously have correlated poorly against measures of functional vision such as patient report outcomes in patients with macular disease. The Central Vision Analyzer (CVA) and Omnifield purport to threshold resolution capability at fixation and throughout the central 20-degree diameter visual field under photopic and mesopic conditions mimicking daily encountered tasks.
Methods :
A retrospective study was conducted in 190 patients with ARMD of varying severity without comorbidities, analyzing the correlation of NEI VFQ-25 patient reported functional vision assessments with habitual spectacle acuity, measured with the ETDRS chart, CVA thresholded central acuity under three photopic conditions at 99% (G1), 10% (G2), and 8% MC (G3) and three mesopic at 99% (M1), 65% (M2), and 43% (M3), and Omnifield parameters at 99% MC of central acuity (CA), best acuity at any intercept within 6 degrees(BA6), global macular acuity (GMA), and resolution area and volume field measures ≥20/40, ≥20/80, and ≥20/160. VFQ responses were grouped into four categories evaluating distance and near-vision tasks (DT and NT, respectively) in either well-lit (WL) or dimly-lit (DL) settings and compared (Pearson correlation coefficients) with estimates of binocular vision from the value measured with the better seeing eye and differences between the two eyes. Although correlations were calculated for both DT and NT, the primary focus of this abstract will be DTs.
Results :
Visual function for DT/WL tasks correlated with chart acuity with Pearson r=0.49. The Pearson coefficients varied among the CVA (M1-3 and G1-3), ranging from 0.19 to 0.33 as well as the Omnifield parameters, ranging from 0.14 to 0.32. Correlations also varied in DT/DL tasks where the CVA and Omnifield demonstrated Pearson correlations that ranged from 0.14 to 0.38, and 0.21 to 0.27, respectively. This is compared to the Pearson correlation of chart acuity with DT/DL, of 0.52.
Conclusions :
The wide disparities of correlations of the various vision measures with VFQ functionality suggest the influence of chronic adaptation that allows persons to manage many vision tasks after prolonged periods even with very poor vision. This indicates the need for VFQ PRO assessments to evaluate the influence of adaptive periods and methods on functionality.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.