Improvement of central retinal sensitivity six months after topical isopropyl unoprostone in patients with retinitis pigmentosa

AIMS: Isopropyl unoprostone (IU), a maxi-K channel activator, is used topically to treat glaucoma, and has been reported to have neuroprotective effects on retinal neurons in vitro and in vivo. The purpose of this non-comparative pilot study was to determine whether topical IU will alter the sensitivity of the central retina in patients with retinitis pigmentosa (RP). SETTINGS AND DESIGN: Non-comparative pilot study. MATERIALS AND METHODS: IU was given topically twice a day for 6 months to both eyes of 30 patients with typical RP. The visual acuity was measured with a Japanese Snellen chart, and the mean retinal sensitivities were obtained by fundus-related microperimetry (MP-1). The mean deviation (MD) of the visual field was determined with a Humphrey field analyzer (HFA). All measurements were made before and 6 months after the treatment. STATISTICAL ANALYSIS USED: Wilcoxon and the Mann-Whitney U tests (SPSS, SPSS Inc., Chicago, IL). RESULTS: After the treatment, the mean retinal sensitivity within the central 2° and 10° improved significantly from 12.3 ± 4.8 dB to 14.7 ± 5.5 dB (P = 0.001) and from 9.1 ± 5.4 dB to 11.0 ± 6.2 dB (P = 0.001), respectively. CONCLUSIONS: These short-term results suggest topical IU can improve the central retinal sensitivity in RP patients. It will be necessary to examine longer treatment periods in a controlled study to determine the effectiveness of topical IU in RP patients.