Other ways to assess RP

Metrics other than visual acuity (VA) and visual field (VF) may be useful for assessing retinitis pigmentosa (RP), according to study results published in the February issue of Eye.

H Nakamura, of the Department of Ophthalmology and Visual Sciences at Kyoto University Graduate School of Medicine, Japan, and colleagues conducted a cross-sectional observational study evaluating the foveal and macular function of three groups of RP patients (n=56), which they assessed using optical coherence tomography (OCT) and focal electroretinogram (fERG) as well as VA and VF tests. The groups were divided as follows: those with no photoreceptor inner/outer segment junction (IS/OS) visible on OCT (Group 1, n=22); those with IS/OS of ≤2 mm (Group 2, n=18), and those with >2 mm IS/OS (Group 3, n=16).

Group 1 patients showed non-recordable fERG and a significantly lower average VA than Group 2 and 3 patients, who had similar VA scores and, on the whole, demonstrated recordable fERG amplitudes. The differences between the amplitudes registered by each group differed significantly, although no implicit time differences between Groups 2 and 3 were shown.

The researchers therefore concluded that, in addition to the traditional VA and VF analysis, fERG amplitudes and an OCT analysis of the IS/OS may aid in assessing foveal and macular function in RP.