AIMS: To investigate relationships between retinal morphology and retinal function in patients with retinitis pigmentosa (RP) using optical coherence tomography (OCT) and multifocal electroretinography (mfERG). METHODS: In all, 14 patients with RP who had visual acuities of 0.2 logMAR or better and Humphrey central fields of 10 degrees or larger participated in the study along with 16 normal control subjects. The amplitudes and timings of the mfERG responses were compared with spatially corresponding measures of retinal layer thickness from OCT within the macula region (central 12 degrees ). RESULTS: Eyes with RP showed thinning of the photoreceptor retinal (PR) layer and thickening of mid-inner retinal (MIR) layers beyond the fovea. mfERG amplitude was reduced in all regions, whereas mfERG timing was only significantly delayed at a retinal eccentricity of 6-12 degrees and was otherwise preserved within the foveal and parafoveal retina (0-6 degrees). PR layer thickness was correlated with mfERG amplitude across the macula region. mfERG timing was correlated with the total change in retinal thickness (combined PR thinning and MIR thickening) at an eccentricity of 6-12 degrees. CONCLUSIONS: The relationship between mfERG timing and retinal thickness in RP is dependent on the retinal eccentricity. Preserved timing in the central retina (0-6 degrees ), despite significant disruption to retinal laminar structure, could be suggestive of inner retinal remodelling or functional redundancy. Cone system activity derived from mfERG amplitude appears to be related to the thickness of the photoreceptor layer in the macula region.
|Journal||Eye (London, England)|
|Publication status||Published - 2009|