Anatomic response of occult choroidal neovascularization to intravitreal ranibizumab: a study by indocyanine green angiography.

Background: To investigate changes in indocyanine green angiography (ICGA) features of occult choroidal neovascularization (CNV) after intravitreal ranibizumab injections.
Methods: We reviewed the charts of all consecutive patients with newly diagnosed occult CNV secondary to age-related macular degeneration (AMD) treated by intravitreal ranibizumab. In all patients, optical coherence tomography (OCT) and ICGA were performed at baseline, after 3 months and 12 months.
Results: Fifty-one eyes of 44 patients (ten males, 34 females, mean age 77.8 ± 7.3 years) were included. Mean follow-up was 20.3 ± 6.2 months. During the first 12 months, patients received 5.5 ± 2.7 intravitreal ranibizumab injections. When compared with baseline, best-corrected visual acuity (BCVA) significantly improved at the 3-month follow-up visit (60.5 ±22.0 vs 50.9 ±20.7 letters, p = 0.04), and stabilized at 12-month visit (55.7 ±18.2 letters; p = 0.05). Central macular thickness (CMT) significantly improved during follow-up (229.0 ±54.7 μm vs 281.0 ±61.3 μm at baseline, p = 0.003). An overall stabilization was observed on ICGA in both the lesion area (5.27 ± 3.9 mm(2) at baseline vs 4.60 ± 3.5 mm(2) at month 12, p = 0.4), and greatest linear dimension (GLD 2.66 ± 1.2 mm at baseline vs 2.55 ± 1.0 mm at month 12, p = 0.3). Eight eyes (15.7%) showed CNV growth on ICGA (lesion area 3.98 ± 3.2 mm2 at baseline vs 4.3 ± 2.7 mm2 at month-12, p = 0.6; GLD 2.11 ± 1.0 mm at baseline vs 2.70 ± 0.8 mm at month-12, p = 0.05).
Conclusion: ICGA suggests that functional outcomes after intravitreal ranibizumab is related to CMT reduction rather than CNV regression.