Author: Beatrice Tombolini (Italy)
Co-authors: Riccardo Sacconi, Domenico Grosso, Paolo Forte, Enrico Borrelli, Francesco Bandello, Giuseppe Querques
Type 3 macular neovascularization (MNV) is an aggressive and often bilateral form of neovascular age-related macular degeneration (nAMD). Although the anti-vascular endothelial growth factor (VEGF) injections therapy has changed the natural history of nAMD, the treatment of type 3 MNV remains tedious with overall worse functional outcomes. In this way, identifying type 3 patterns featuring less favorable prognosis is of paramount importance. The aim of this study is to identify baseline optical coherence tomography (OCT) predictors of the 3-year visual outcome for type 3 MNV secondary to AMD treated by anti-VEGF therapy.
This is a longitudinal study of patients enrolled in Medical Retina and Imaging Unit of the Department of Ophthalmology, San Raffaele Scientific Institute in Milan, Italy.
Patients affected by exudative treatment-naïve T3 MNV were enrolled. The following baseline OCT features were analyzed: AMD phenotype (presence of drusen, reticular pseudodrusen, or both), presence of atrophy of retinal pigment epithelium, T3 stage, foveal involvement of exudation, AMD stage in the fellow-eye (dry AMD or nAMD), number of active T3 lesions, central macular thickness (CMT), subfoveal choroidal thickness (ChT), mean ChT, sublesion ChT, presence of hyperreflective dots (HRD), presence of intraretinal fluid (IRF), subretinal fluid (SRF), subretinal hyperreflective material (SHRM), pigment epithelium detachment, and neuroretinal thickness above the lesion. Univariate and multivariate analyses served to identify risk factors associated with the 3-year BCVA. Factors included in the multivariate model needed a p-value<0.3 in the univariate analysis.
40 eyes of 30 patients (mean age 79±6 years old) were enrolled. Mean baseline best-corrected visual acuity (BCVA) was 0.34±0.28 LogMAR and significantly decreased to 0.52±0.37 LogMAR at the end of 3-year follow-up (p=0.002). Nineteen eyes were classified as Stage 2 T3 MNV, whereas 21 eyes as Stage 3. All patients displayed HRD and IRF at the baseline. In the univariate analysis, the following baseline features were associated with the 3-year BCVA outcome: baseline BCVA (p=0.007), AMD phenotype (p=0.041), foveal involvement of exudation (p=0.014), and presence of SRF (p=0.019). In the multivariate model, baseline BCVA (B=0.373, p=0.017), CMT (B=-0.363, p=0.045), number of active T3 lesions (B=-0.290, p=0.042), and presence of SRF (B=0.467, p=0.005) were associated with the 3-year BCVA outcome. Interestingly, 3-year BCVA was significantly lower in 19 eyes with SRF at the baseline (0.69±0.42 LogMAR) in comparison to 21 eyes without SRF (0.37±0.24 LogMAR, p=0.004).
The identification of biomarkers is of paramount importance in order to predict outcomes. In this study, we identified structural OCT features associated with the BCVA outcome after 3-year treatment with anti-VEGF injections. Differently from previous studies on nAMD, in our series the presence of SRF at the baseline was the most significant independent negative predictor of functional outcomes. Current findings may be employed to identify less favorable T3 patterns potentially deserving a more intensive treatment.