Per-region visual field sensitivities and delays in AMD

Abstract

Purpose : To compare central vs. peripheral visual field sensitivities and delays in neovascular AMD (nAMD) and earlier-stage fellow eyes using FDA-cleared multifocal pupillographic objective perimetry (mfPOP).

Methods : We recruited 18 nAMD patients testing both eyes concurrently. Practitioner directed intravitreal anti-VEGF injection was administered monthly for 14 to 28 visits. Diagnostic procedures included mfPOP, Matrix 10-2 perimetry, and OCT. The macular mfPOP variant had 44 interleaved stimuli/eye presented from fixation to 15^o eccentricity. We examined correlations between central and peripheral mfPOP per-region sensitivities and delays within eyes, and between nAMD eyes and untreated fellow eyes.

Results : Twenty-three eyes of 18 patients were tested (14 females, 77.8%). In treated eyes central sensitivity decreased over time by -2.23 ± 0.051 dB/month (p<0.0002). Untreated fellow central sensitivity declined at -0.17 ± 0.07 dB/month (p=0.033). Treated eyes showed quicker central responses by 13.08 ± 3.77 ms than untreated eyes (p=0.001). Based on peripheral sensitivities and delays we have identified two patient categories: positive types with hypersensitivity and longer delays, and negative types with hyposensitivity and shorter delays compared to normal controls. When analysed separately mfPOP data showed an ability to predict the need for anti-VEGF injection. Among the positive eyes peripheral sensitivity increased by 9.88 ± 4.41 dB (p=0.042) before treatment, and delays increased by 3.49 ± 1.75 ms/month (p=0.049). For the negative eyes, the peripheral sensitivity dropped, and the delay was shorter a month before the treatment by 9.38 ± 3.59 (p=0.013), and a month following treatment it improved towards normal values (shorter by 8.50 ± 2.71 ms, p=0.004).

Conclusions : We observed decreased central sensitivity, and coincident peripheral hypersensitivity. In the untreated fellow eyes, the central sensitivity decreased and delay increased progressively until treatment was needed. Based on peripheral responses the eyes could be divided into positive and negative groups. The predictive value of mfPOP improved after the positive and negative eyes were analysed separately. Diagnostic sensitivity and delay changes could precede active disease by 1 to 3 months. We conclude that mfPOP may be a potential biomarker to predict the need for anti-VEGF injections in nAMD.

This is a 2021 ARVO Annual Meeting abstract.