Abstract
Purpose :
Our earlier study showed that the width of the intact ellipsoid zone (EZ) of the photoreceptors was significantly but weakly correlated with the amplitudes of the focal macular electroretinograms (FMERGs). The aim of this study was to determine a microstructure of the photoreceptors in the spectral domain optical coherence tomographic (SD-OCT) images that was more strongly correlated with the FMERG parameters in eyes with retinitis pigmentosa (RP).
Methods :
This was a retrospective, observational study. The medical records of 65 patients with RP were reviewed. FMERGs were elicited by a 15 degrees stimulus spot. The width of the EZ and the outer segment (OS) area surrounded by EZ and retinal pigment epithelium in the SD-OCT images within 15 degrees of the fovea were evaluated. Spearman correlation tests and multiple stepwise regression analyses were performed.
Results :
There was a strong correlation between the amplitudes of FMERGs and the EZ width (r=0.68 for a-wave amplitude; r=0.64 for b-wave amplitude), and also between the amplitudes of the FMERGs and the OS area (r=0.69 for a-wave amplitude; r=0.67 for b-wave amplitude). However, some patients had long EZ widths but had severely reduced FMERGs. Multiple stepwise regression analyses showed that the OS area was the only significant independent predictor of the amplitudes of FMERGs (P<0.001).
Conclusions :
The OS area might be a better morphological structure to use to predict the physiological function of the macula in the early stage of RP.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.