Contrast Sensitivity (CS) in Age-Related Macular Degeneration (ARMD) with Choroidal Neovascularization (CNV)

Purpose. Contrast sensitivity was tested in patients enrolled in a prospective study in order to follow CS changes over time. Measures with the Vistech grating chart and the Pelli-Robson (PR) letter chart were compared. Methods. Twenty nine patients with active CNV secondary to ARMD underwent CS testing with the Vistech grating chart and PR letter chart. Data have been obtained at baseline, 3 weeks , 6 weeks, and 12 weeks after enrollment. Paired t tests were used to assess differences between the Vistech and PR charts with respect to CS threshold and its change over time. Pearson correlations were used to test the relationship between the CS measures and visual acuity (VA) at both distance and near, as well as for changes over time. Results. Average log CS with the PR chart was significantly lower than normal, but there was a trend towards improvement from 0.80 to 1.02 at baseline, 3 weeks, 6 weeks and 12 weeks follow-up. For the Vistech chart, CS at 1.5 cycle per degree was closely correlated to measures with the PR chart. There was no correlation between VA and CS with either method. Conclusions. CS testing did not correlate with VA in patients with active CNV secondary to ARMD. Correlation between the Vistech 1.5 cycle per degree and Pelli-Robson charts reflects the loss of CS at high spatial frequency due to the pronounced macular dysfunction in these patients.