Selective reduction of the light peak-to-dark trough ratio in reticular macular disease: an electrooculography study

To compare electrooculogram (EOG) parameters between eyes with reticular macular disease (RMD) and eyes with early-to-intermediate age-related macular degeneration (AMD) without reticular pseudodrusen (RPD), and to assess whether RMD is associated with generalized RPE-photoreceptor complex dysfunction.

In this observational cross-sectional study, 42 eyes from 21 patients were analyzed (without-RPD group: 28 eyes; RMD group: 14 eyes). RMD was diagnosed using multimodal imaging (infrared reflectance and SD-OCT). EOGs were recorded with the RETI-port/scan 21 system according to ISCEV standards. Extracted parameters included dark trough (DT), light peak (LP), light rise time (Light Rise), and the LP:DT ratio. Group comparisons used the Wilcoxon rank-sum test. Linear regression evaluated the association between RMD and LP:DT ratio with and without adjustment for age.

Age did not differ between groups (median 69 vs. 72 years; P = 0.5). Absolute standing potentials were similar (DT: 598 vs. 681 μV, P = 0.2; LP: 1,092 vs. 1,150 μV, P = 0.8). Light rise time was also similar (8.00 [IQR 7.50-9.00] vs. 8.00 [IQR 7.00-9.00] min; P = 0.6). In contrast, the LP:DT ratio was significantly reduced in RMD (1.65 [1.50-1.80]) compared with without-RPD controls (1.90 [1.80-2.10]; P = 0.0043). RMD was independently associated with a lower LP:DT ratio (β = -0.25, 95% CI [-0.41 to -0.09]; P = 0.004).

Compared with AMD eyes without RPD, RMD eyes demonstrate a selectively reduced LP:DT ratio without a change in absolute standing potentials or light rise timing. This EOG pattern supports attenuated light response consistent with generalized dysfunction of the RPE-photoreceptor complex in RMD.