Abstract
Purpose: :
To compare the outcomes of two treatment protocols for neovascular age related macular degeneration: Loading dose (3+PRN) versus PRN dosing from baseline.
Methods: :
This retrospective study assessed 78 consecutive patients (78 eyes) with visual acuity between 24 and 73 letters due to all subtypes of neovascular age related macular degeneration treated with ranibizumab and followed up for twelve months. The patients were divided into two treatment groups: I) 3+PRN consisting of three initial injections at monthly intervals followed by OCT guided retreatment and II) a pro re nata-PRN dosing schedule with OCT guided retreatment criteria from start of therapy. The main outcome measures compared in the two treatment groups were change in visual acuity (VA) and central macular thickness (CMT).
Results: :
The mean VA at baseline was 48± 15.25 and 44.48 ± 15.41 ETDRS letters in the 3+prn and prn group respectively. In the 3+ prn group (n=47), 89.01% and in the prn group(n=31) 93.1% maintained stable vision. However 29% had more than 15 letter improvements in the 3+prn group compared with 12.9% in prn group (p=0.04). The mean change in VA at 12 month of +6.4 in the 3+prn and +3.9 in the prn group (p=0.35). The mean change in CMT at 12 months was -37.5 in the 3+prn and-43.5 prn group respectively (p=0.6).The mean number of ranibizumab injections was 6.0 in the 3+prn group and 4.5 in the prn group.
Conclusions: :
More patients achieved visual improvement in the 3+prn group compared to the prn group, even though there was no significant difference in the CMT. This suggests the superiority of the 3+prn schedule over the prn group.
Keywords: age-related macular degeneration • visual acuity • choroid: neovascularization