Fourier-domain optical coherence tomography and microperimetry findings in retinitis pigmentosa

Purpose: To investigate the relation between the optical coherence tomography (OCT) findings and retinal sensitivity in patients with retinitis pigmentosa (RP) by assessing the retinal thickness and retinal function using Fourier-domain OCT (FD-OCT) and microperimetry, respectively.

Design: Observational case series.

Methods: Fifty-nine patients (118 eyes) were enrolled, mean age 47 ± 14.8 years. Thirty-two healthy subjects (HS) were enrolled as a control group. Patients were assessed by means of FD-OCT and microperimetry. We analyzed the average foveal thickness (diameter of 1 mm centered on the point of fixation), the value of the retinal sensitivities corresponding to the 4 degrees centered on the fixation point, and logMAR visual acuity for regression analysis converted from Snellen chart.

Results: We distinguished 4 groups of RP patients according to the macular pattern seen on OCT images. The first group of 36 eyes, mean age of 33.5 ± 7.4 years, had no macular changes, mean best-corrected visual acuity (BCVA) of 0.95 ± 0.07, mean foveal thickness of 256.3 ± 9.14 μm, and mean retinal sensitivities inside the central 4 degrees of 19.27 ± 0.87 dB (P > .05 for all the values). The second group of 28 eyes, mean age 35.4 ± 6.3 years, showed clinical macular edema (CME) on OCT images with mean BCVA of 0.72 ± 0.22, mean foveal thickness of 363.5 ± 93.45 μm, and mean retinal sensitivity inside the central 4 degrees of 15.94 ± 3.6 dB (P < .01 for all the values). The third group of 26 eyes, mean age 50.8 ± 8.7 years, showed macular vitreoretinal traction on OCT images with a mean BCVA of 0.5 ± 0.2, mean foveal thickness of 337.1 ± 71.7 μm, and mean retinal sensitivity inside the central 4 degrees of 11.78 ± 3.09 dB (P < .01 for all the values). The last group of 28 eyes, mean age 52.1 ± 13.6 years, showed macular retinal thinning on OCT images with mean BCVA of 0.36 ± 0.15, mean foveal thickness of 174.2 ± 24.40 μm, and mean retinal sensitivity inside the central 4 degrees of 10.22 ± 3.82 dB (P < .01 for all the values).

Conclusions: MP-1 and FD-OCT showed high sensitivity for identifying functional and structural macular abnormalities, respectively. Future studies should investigate the relationships among photoreceptor cell loss, retinal sensitivity, and fixation in patients with RP.