Abstract
Purpose: :
to assess functional and structural retinal changes in patients with choroidal neovascular membrane secondary to age related macular degeneration (AMD) treated with intravitreal Ranibizumab 0.5 mg.
Methods: :
Eighteen consecutive patients with neovascular AMD were included in this retrospective follow-up study. All patients have been treated with three consecutive injections of Ranibizumab 0.5 mg 1 month apart. Patients showing either a decrease of visual acuity (VA) > 5 letters or a 100 µm increase in macular thickness or evidence of subretinal fluid or new subretinal hemorrage have been retreated according to a predefined treatment protocol. At baseline all subjects performed VA measurement (ETDRS charts), fluorescein angiography, MP1 Microperimetry and Optical Coherence Tomography (OCT Stratus). Follow up visits were scheduled at 1, 7, 28±2 days after each injection. ETDRS measurement, MP1 and OCT Stratus evaluations were repeated 28±2 days after each injection. Primary endpoint was defined as an improvement of MP1 retinal sensitivity at 24 weeks from baseline and secondary endpoints included improvement of number of ETDRS letters and thinning of macular thickness.
Results: :
MP1 mean retinal sensitivity significantly improved from 3.89±3.0 dB to 6.61±3.4 dB at 24 weeks (p=0.044). Fifty percent (n 9) of patients showed an improvement of retinal sensitivity ≥ 2.5 dB (mean 4.69±1.63 dB, IC 95% 3.43-5.94) and 50% (n 9) presented a retinal sensitivity improvement < 2.5 dB (mean 0.73±0.92 dB, IC 95% 0.02-1.44). The number of ETDRS letters improved from 48.67±8.58 at baseline to 60.72±16.09 at 24 weeks (p=0.026); VA improved in 44.4% of patients ≥15 letters, while 38.9% of patients improved <15 letters and 16.7% lost <15 letters. Central macular thickness significantly decreased form 310.5±85.7 to 217.3±46.8 µm at 24 weeks (p<0.001). While the mean retinal thickness measured by OCT resulted to be significantly influenced by the baseline retinal thickness (R2=0.71, p<.0001), with best results expected in thicker maculas, the mean retinal sensitivity and VA at 24 week seemed not to be influenced by the baseline conditions (R2=0.07, p=0.27 and R2<.0001, p=0.99) even after adjusting for the type of AMD lesion (R2= 0.22, p=0.34 and R2=0.03, p=0.76).
Conclusions: :
After six months of treatment with Ranibizumab 0.5 mg patients with neovascular AMD showed a significant retinal functional improvement as shown by increased mean retinal sensitivity and visual acuity associated with a significant decrease of central macular thickness.
Keywords: age-related macular degeneration • vascular endothelial growth factor • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)