Photoreceptor integrity and visual acuity in retinitis pigmentosa

Abstract

AbstractPurpose To assess the correlation between the status of the inner segment/outer segment junction (IS/OS) and visual acuity in retinitis pigmentosa.Methods One hundred and ninety‐six eyes of 100 patients with RP were examined with the spectral optical coherence tomography (3D‐OCT‐2000). The status of the inner segment/outer segment junction (IS/OS) (Grade 1: absent, Grade 2: blurred discontinuous, or Grade 3: distinct) was evaluated. Correlation between visual acuity and each of the measurements were examined.Results Of the 196 eyes, IS/OS was absent in 61 eyes (30.9%), blurred in 71 eyes (36.36%) and distinct in 64 eyes (32.74%).Total retinal thickness was not correlated with visual acuity. The mean logMAR visual acuity (VA) in the IS/OS absent group (0.65±0.12) was worse than the one seen in the IS/OS blurred (0.23±0.41) or IS/OS distinct groups (0.08±0.44) (P<0.001). But eighteen per cent of the eyes with a normal foveal IS/OS line, normal COST line and normal perifoveal layers have a bad visual acuity. While seven per cent of eyes with absent foveal IS/OS line have surprisingly a good visual acuity.Conclusion The status of photoreceptor IS/OS line is an important parameter that needs to be examined in RP patients, while perifoveal retinal layers need not be examined. The presence of the foveal photoreceptor IS/OS line is associated with better visual acuity and thicker fovea in RP patients. But, in a few cases, the foveal photoreceptor IS/OS line can be absent with a good visual acuity.