RATES OF CHANGE DIFFER AMONG MEASURES OF VISUAL FUNCTION IN PATIENTS WITH RETINITIS-PIGMENTOSA

Purpose: To assess changes in measures of visual function in patients with retinitis pigmentosa (RP) over time. Methods: Patients with RP an d visual acuity of 20/40 or better and central visual fields of 10 deg rees or larger were enrolled in a 9-year prospective study. The follow ing measures of visual function were obtained annually over the follow -up period: visual acuity, Goldmann visual fields (V4e target), focal electroretinograms, and hue discrimination. Results: Over the follow-u p period, the averaged group data showed changes in all measures of vi sual function. The smallest amount of change occurred for visual acuit y and hue discrimination, and the greatest amount of change occurred f or visual field area. Examination of individual patient data over the follow-up period indicated that the rates of change varied among patie nts and that losses in function for one measure did not correlate well with losses on other measures. Conclusions: These results stress that although visual function deteriorated over time for this group of pat ients with RP, there were differences among our measures of visual fun ction. Measures that primarily assess central retinal function change relatively slowly compared with measures that assess more peripheral r etinal function.