Correlation between aqueous flare levels and anti-VEGF treatment response in wet age-related macular degeneration

Abstract

Purpose

To analyze the association between aqueous flare and wet age-related macular degeneration (AMD) activity during anti-VEGF treatment using the treat-and-extend (T&E) protocol.

Methods

A single-centre study consisting of 84 eyes of 84 patients with wet AMD and 17 eyes of 17 patients with dry AMD at Ophthalmology Unit, Mehiläinen Hospital, Helsinki, Finland. Aqueous flare levels were recorded with a laser flare meter. Inclusion criteria was a minimum of six anti-VEGF doses given before enrollment to the study.

Results

Aqueous flare levels inversely correlated with the anti-VEGF treatment interval (R²= 0.16, P < 0.001). In the group with a 4–6-week treatment interval the aqueous flare was 13.6 ± 8.3 photon units (pu)/ms compared to 7.9 ± 2.9 pu/ms (P = 0.008), 7.8 ± 3.5 pu/ms (P = 0.006), and 7.2 ± 3.8 pu/ms (P = 0.002) among patients with 7–9-week, 10–12-week, and 13–16-week intervals, respectively. Aqueous flare was 15.4 ± 8.5 pu/ms in the group whose treatment intervals were shortened, compared to 8.6 ± 3.8 pu/ms (P = 0.003) and 7.3 ± 3.3 pu/ms (P < 0.001) in the groups where the treatment intervals were maintained or extended, respectively. Furthermore, aqueous flare levels correlated with the macular volume (R²= 0.07, P = 0.018). Regarding macular activity, the presence of intraretinal fluid associated with higher aqueous flare levels (13.8 ± 8.6 pu/ms) compared to those without it (8.0 ± 4.0 pu/ms; P < 0.001). Patient age, pseudophakia or the anti-VEGF agent did not associate with the aqueous flare levels.

Conclusions

Aqueous flare measurements correlated with wet AMD activity during anti-VEGF treatment. Aqueous flare could be used to help evaluate the state of wet AMD patients and assist in decisions regarding anti-VEGF treatment modifications.