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

To investigate changes in indocyanine green angiography (ICGA) features of occult choroidal neovascularization (CNV) after intravitreal ranibizumab injections.

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.

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 mm² at baseline vs 4.60 ± 3.5 mm² 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).

ICGA suggests that functional outcomes after intravitreal ranibizumab is related to CMT reduction rather than CNV regression.