Quantification of the Visual Field Loss in Retinitis Pigmentosa Using Semi-Automated Kinetic Perimetry

Abstract

ABSTRACT Purpose: To assess quantitatively the natural course of the visual field (VF) loss in patients with retinitis pigmentosa (RP) during 2-year period of observation. Methods: VFs were obtained by semi-automated kinetic perimetry (SKP) during four examinations of 16 patients suffering from RP. Three stimulus conditions (V4e, III4e and I4e) with a constant stimulus angular velocity of 3°/s were used to assess the hill of vision in both eyes of each patient. The area of each isopter was measured in square degrees and corrected for the individual reaction time (RT). Results: There were four patients with mild restriction of VF, six with ring scotomas and six with advanced concentric constrictions of VF. Only I4e isopter area decreased significantly from the first to the last session (p = 0.006), the difference was 154 deg2 being 13% of initial isopter area. The difference was not significant for V4e and III4e isopters. RT values did not differ significantly between four sessions. Conclusions: Only I4e isopter’s area was decreased significantly during two years of observation. SKP provides a method of assessment of progression of the VF loss in patients suffering from RP by measurement of the isopters’ area over time.