Retinal functional changes measured by microperimetry in neovascular age-related macular degeneration treated with...

The purpose of this study was to assess long-term functional and structural retinal changes in patients with neovascular age-related macular degeneration treated with intravitreal 0.5 mg ranibizumab.

Eighteen patients with neovascular age-related macular degeneration have been evaluated in this retrospective 24-month follow-up study. All patients have been treated with 3 injections of 0.5 mg ranibizumab 1 month apart and retreated according to predefined criteria. At baseline, all patients were subjected to visual acuity, fluorescein angiography, MP1 microperimetry, and Stratus optical coherence tomography. Although visual acuity and optical coherence tomography were repeated 28 +/- 2 days after each injection, MP1 was performed at 6, 12, and 24 months.

Seventeen of 18 and 14 of 18 patients completed 12 and 24 months of follow-up, respectively. Mean retinal sensitivity significantly improved from 3.89 +/- 3.0 dB to 7.33 +/- 4.11 dB at 24 months (P = 0.024). Mean visual acuity improved from 48.67 +/- 8.59 to 59.17 +/- 16.45 at 24 months (P = 0.049). Visual acuity improved to >or=15 letters in 33.3% (6 of 18) of patients and <15 letters in 44.4% (8 of 18); 22.2% (4 of 18) of patients lost <15 letters at 24 months. Five of 13 patients (38.5%) with either an instable or relatively instable fixation at baseline showed improvement of fixation stability at 24 months. Central retinal thickness significantly decreased from 310.5 +/- 85.7 to 232.9 +/- 60.1 at 24 months (P = 0.0001).

Intravitreal injections of 0.5 mg ranibizumab determine progressive improvement of retinal sensitivity until 24 months, although visual acuity levels off after 6 months, suggesting that microperimetry may give additional information about macular function not given by visual acuity alone.