The structure-function relationship measured with optical coherence tomography and a microperimeter with auto-tracking: the MP-3, in patients with retinitis pigmentosa

The purpose of the current study was to investigate the structure-function relationship in patients with retinitis pigmentosa (RP) using optical coherence tomography and the MP-3 microperimeter. Visual field (VF) measurements were carried out using MP-3 microperimetry and the Humphrey Field Analyzer (HFA, Carl-Zeiss, CA), 22 eyes of 11 patients with a clinical diagnosis of RP, both with the 10-2 test grid pattern. Optical coherence tomography (OCT, Spectralis, Heidelberg, Germany) was also performed and the ellipsoid zone (EZ) was identified in the OCT image. The mean (±SD) number of test points located within the EZ edge was 11.6 (±5.9). There was a significant relationship between mean retinal sensitivity measured with MP-3 and the area surrounded by the EZ circular line: AEZ (p < 0.05), but this was not the case with HFA (p > 0.05). The difference between retinal sensitivity inside and outside the EZ edge was significantly larger with MP-3 than with HFA (p < 0.001). Our findings suggest that retinal sensitivity measured with MP-3 better reflects the magnitude of structural damage observed with OCT, compared with HFA. Further, the difference in retinal sensitivity between the inside and outside EZ edge is significantly larger for the MP-3 test, compared with the HFA.