Abstract
Purpose :
To compare two aflibercept treatment regimens and the electrophysiological outcome concerning cone and rod function in nAMD over 18 months.
Methods :
41 patients with treatment-naïve nAMD were randomized 1:1 either to arm 1 or 2. Arm 1 received three consecutive monthly aflibercept injections, followed by bimonthly treatment until week 52, thereafter treat-and-extend (TAE) regimen was applied. Arm 2 was treated according to a TAE protocol throughout the 18-month follow-up. We assessed visual acuity (VA), central retinal thickness (CRT), injection rate and interval, and evaluated cone and rod function with full-field and multifocal electroretinography (ffERG, mERG).
Results :
There was no statistically significant difference concerning mean baseline VA, lesion type, age, gender, or symptom duration between the two arms. During the 18-month follow-up, mean VA improved in arm 1 (n= 19) from 63.5 ± 10.5 to 69.1 ± 9.2 letters; p= .098; and in arm 2 (n= 20) from 66.8 ± 13.6 to 73.9 ± 9.0 letters; p= .002. Mean CRT was reduced from 327.8 ± 87.6 mm to 218.1 ± 34.4 mm in arm 1; p< .000. In arm 2, CRT decreased from 303.7 ± 92.0 mm to 226.4 ± 32.3 mm; p< .000. At month 18, we found no significant difference concerning number or injections or injection intervals between groups. Arm 1 had received 11.3 ± 1.7 injections vs. 10.9 ± 2.0 in arm 2. The mean injection interval was 9.2 ± 3.4 weeks vs. 9.5 ± 3.1, with 52% (n= 10) on the maximum twelve-week interval in arm 1, and 50% (n= 10) in arm 2. The combined rod-cone a-wave amplitude significantly decreased over time; p= .043. The isolated rod b-wave amplitude showed a statistically significant decline; p= .026. The overall mERG amplitude and implicit time remained unchanged over time; p= .878 vs. p= .922. The central ring 1 mERG amplitude improved; p= .041, with uneffected implicit time.
Conclusions :
After 18 months, both treatments arms have received similar number of injections at comparable intervals. Electrophysiological evaluation shows no signs of toxicity concerning cone function. But ffERGs for the combined and isolated rod response have declined, maybe reflecting either toxic effects of the drug to rods or the natural course of the disease itself.
This is a 2020 ARVO Annual Meeting abstract.