Chromatic Full-Field Stimulus Thresholds in Patients with Treatment-Naive Age-Related Macular Degeneration

To evaluate retinal sensitivity using chromatic full-field stimulus thresholds (FST) in patients with treatment naive exudative age-related macular degeneration (e-ARMD) before and during the first intravitreal anti-vascular endothelial growth factor (anti-VEGF) treatment.

After general ophthalmological examinations to diagnose patients with e-ARMD the FST, the central foveal thickness (FCt) and the visual acuity were assessed in 20 eyes of 20 patients during this prospective study. Examinations were performed before and during the first treatment series with three intravitreal anti-VEGF injections. Normal values for FST were assessed in 19 eyes of 19 healthy subjects. Results were analyzed using Student's two-tailed t-test and Pearson's correlation coefficients between all functional parameters.

At baseline and before the 1st intravitreal anti-VEGF treatment, a moderately significant negative correlation between VA and FCt was found in the e-ARMD group (p = 0.02, r = -0.45 and p = 0.03, r = -0.45), respectively. After the 2nd intravitreal anti-VEGF injection, no significant correlation between VA and FCt was found (p = 0.12). However, a significant correlation between FCt and blue FST was evident (p = 0.04, r = 0.4). After the 3rd intravitreal anti-VEGF treatment, there was no correlation evident between VA and FCt (p = 0.31) but a high significant correlation between FCt and FST using red (p = 0.01, r = 0.53), green (p = 0.002, r = 0.6) and blue light (p = 0.007, r = 0.66).

During anti-VEGF treatment in patients with e-ARMD, the FST test showed higher significant correlations with the morphology measured by FCt, as it is the case for VA. These findings support that the FST test might serve as a valuable diagnostic tool for monitoring patients with e-ARMD and enhance functional assessment of retinal function under treatment with anti-VEGF.