Glial proliferation and atrophy: Two poles of optic disc in patients with retinitis pigmentosa

PURPOSE: To clarify the difference of retinal nerve fiber layer (RNFL) thicknesses between patients with retinitis pigmentosa (RP) and normal subjects. METHODS: The study included right eyes of 30 patients with non-late-stage RP, which had a waxy pallor in OD, attenuation in retinal arterioles, and midperipheral bone spicule pigmentary changes. To compare the RNFL analysis with normal subjects, the right eyes of 30 age- and gender-matched healthy subjects were included as a control group. RESULTS: There were no differences between the RP and control groups in terms of demographic and baseline characteristics (P > 0.05, for all). The mean temporal quadrant RNFL thickness was 102.9 ± 31.7 μm (43–222) in the RP group and 72.4 ± 11.8 μm (51–90) in the control group (P < 0.001). The mean nasal quadrant RNFL thickness was 57.6 ± 33.7 μm (21–140) in the RP and 75.0 ± 14.1 μm (56–132) in the control group (P < 0.001). There were no significant RNFL thickness differences between the groups in other sectors and globally (P > 0.05, for all). There was no significant correlation between temporal RNFL thickening and ageing (r = −0.136, P = 0.196) while there was a significant correlation between nasal RNFL thinning and ageing (r = −0.274, P = 0.047). CONCLUSIONS: RNFL is thicker in temporal quadrants and thinner in nasal quadrants in non-late stage RP. Age-related decreases in RNFL thickness occurred earlier in the nasal quadrant and RNFL thickening in the temporal quadrant occurred earlier than this global thinning.