Correlation Between Mesopic Retinal Sensitivity and Optical Coherence Tomographic Metrics of the Outer Retina in Patients With Non-Atrophic Dry Age-Related Macular Degeneration.

BACKGROUND AND OBJECTIVE: To determine the correlation between mesopic retinal sensitivity and optical coherence tomographic metrics of the outer retina in patients with intermediate age-related macular degeneration (AMD).

PATIENTS AND METHODS: Participants with nonatrophic dry AMD underwent mesopic MP-3 microperimetry (Nidek, Padova, Italy) and both Nidek and Cirrus (Carl Zeiss Meditec, Dublin, CA) spectral-domain optical coherence tomography (SD-OCT). The volume of the outer retinal layers was measured on the Nidek SD-OCT scans using the automatic segmentation algorithm of Navis-EX software. In addition, drusen area and volume within a 5-mm circle centered on the fovea were determined using the Cirrus Advanced RPE Analysis Tool. The mean retinal sensitivity at 8° and 10° of fixation (5-mm and 6-mm circles) was calculated for every eye. The correlation between retinal sensitivity and patient age, outer retinal layer volume, drusen area, and drusen volume was assessed.

RESULTS: Thirty-seven eyes from 25 patients with non-atrophic dry AMD were included in the study. The mean age of the patients was 76 years ± 9 years. The mean sensitivity across the whole tested retinal area was 24.9 dB ± 2.4 dB, with a sensitivity of 25.1 dB ± 2.4 dB within the central 5-mm circle. Drusen area within the central 5-mm circle was 0.7 mm2 ± 0.89 mm2 with a drusen volume of 0.03 mm3 ± 0.04 mm3 . Retinal pigment epithelium and photoreceptor outer segment (RPE + OS) volume was 1.96 mm3 ± 0.1 mm3 , and outer nuclear layer (ONL) volume was 1.91 mm3 ± 0.17 mm3 . There was a significant correlation between RPE + OS volume and retinal sensitivity, as well as between patients' age and retinal sensitivity. There was no significant correlation between drusen area or volume and retinal sensitivity, nor between ONL volume and retinal sensitivity.

CONCLUSION: In eyes with nonatrophic AMD, retinal sensitivity is correlated with the RPE + OS volume, but not the ONL volume or the area or volume of drusen. [Ophthalmic Surg Lasers Imaging Retina. 2017;48:312-318.].