Abstract
Purpose:
CRVO Patients with macular edema completing the 1-year prospective CoRaLa trial evaluating the effect of combination of intravitreal ranibizumab injections with laser photocoagulation of peripheral non-perfused retina were followed for additional 12 months.
Methods:
In the CoRaLa trial (Combination of Ranibizumab and Laser) 22 patients were randomized. The experimental arm (n=10) was treated with ranibizumab and additional laser photocoagulation; the control arm (n=12) received ranibizumab only. Due to small sample size the 1-year results (end of study) showed obvious but non-significant differences in the gain of 14.1 ETDRS letters in the laser arm compared with 8.0 letters in the control arm. We followed the patients over further 12 months after completing the study and evaluated the changes in the best corrected visual acuity and central retinal thickness (CRT). The medians of the group differences from these retrospective analyses were evaluated. Further, the need of further treatment, and the proportion of subjects developing the neovascularizations were evaluated.
Results:
Patients treated with ranibizumab and laser gained between baseline and month 24 in median 13.3±4.7 ETDRS letters. The gain in control arm was 6.1±9.7 ETDRS letters. The median of CRT-reduction was on month 24 in the laser group 328±131.4 µm and in the control arm 397±214 µm. During the second year (follow-up period) 7 (70%) of laser treated patients did not required any further treatment compared with 4 (33%) patients in the control group. In patients with need for retreatment in mean 1.6 ranibizumab injections in the laser arm, and 3.6 Injection in the control arm were applicated. In 5 patients from control group and 1 in laser arm the dexamethason implant was additionally given. No patient in the laser group and 2 patients in the control arm developed neovascularizations of retina requiring the rescue scatter laser treatment.
Conclusions:
The selective laser photocoagulation of peripheral areas of non-perfusion seems to lead to sustain reduction of macular edema with additional visual improvement and reduction of the need for retreatment in the second year of ranibizumab therapy in CRVO. Further larger trial is needed to confirm these results of this pilot study.