Temporal Relationship Between Different Measures oVisual Function in Patients With Neovascular Macular Degeneration Treated With Photodynamic Therapy

Abstract

Purpose: : Distance vision (DV), near vision (NV) and contrast sensitivity (CS) are important measures of vision used in the monitoring of patients with macular disease. The aim of this study was to determine the relationship over time in a group of patients with neovascular macular degeneration (nMD) being treated with photodynamic therapy (PDT).

Methods: : Patients attending a regional centre for treatment of nMD with PDT were recruited and followed at approximately 3 monthly intervals. Refraction protocol: best-corrected DV, NV and CS were measured by accredited testers using 2m logMAR, 25cm logMAR and 1m Pelli-Robson charts respectively using standard illumination. Patient data were represented by least squares polynomials of order 2, evaluated by interpolation over the intervals (0 2 4 6 8 10 12 14 16 18) months and summarised as ensemble averages, with weighting in local n to allow for censoring, for far, near and contrast over the interval of 0 to 12 months.

Results: : Data were available on patients commencing treatment between 1999 and 2006; DV:n=400, NV: n=363, CS: n=372. Average follow-up was 400 days. Average scores changed over the follow-up period as follows; DV: 48 to 39, NV: 1.05 to 1.20, CS: 23 to 23.2

Conclusions: : At presentation, patients with nMD are borderline visually impaired and steadily lose moderate amounts of DV during the 400 days of follow-up during a course of PDT. NV deteriorates slightly from the poor level at presentation. In contrast, CS is preserved at a fair level throughout.

Keywords: photodynamic therapy • age-related macular degeneration • low vision