Background/aims To investigate the factors associated with macular atrophy (MA) growth rates in neovascular age-related macular degeneration treated with either ranibizumab or aflibercept.

Methods We obtained data from two identical prospective studies using ranibizumab or aflibercept under observe-and-plan variable dosing regimens. We analysed eyes that presented MA within 2 years. After applying square root transformations to MA sizes, we calculated MA growth rate from baseline to the year 2 endpoint and used univariate and multivariate analyses to detect ocular and treatment factors associated with the MA growth rate.

Results Included were 109 eyes from 101 patients (mean age 80.6 years). The mean square-root-transformed MA growth rate was 0.54±0.34 mm/year. The univariate analyses revealed that MA growth rates were significantly associated with lower baseline visual acuities (p=0.001) and thicker subretinal tissue complexes (p=0.006) and near-significantly associated with the presence of pigment epithelium detachment (p=0.057) and choroidal neovascularisation subtypes (p=0.069). Our multivariate analysis confirmed the significance of lower baseline visual acuities (p=0.008) and pigment epithelium detachments higher than 200 µm (p=0.035). Furthermore, MA growth rates in neovascular eyes significantly correlated with MA growth rates in non-neovascular fellow eyes (n=61; p=0.003).

Conclusion MA growth rates were associated with ocular factors in the study eyes and the fellow eyes but not with the drug or the number of injections within this variable dosing regimen.