Comparative treatment study on macular edema secondary to branch retinal vein occlusion by intravitreal ranibizumab with and without selective retina therapy.

Abstract

Purpose : Selective retina therapy (SRT) was developed as unique laser procedure in which the RPE is selectively disintegrated by microbubble formation within RPE cells, without affecting the neural retina, Bruch’s membrane and the choroid. Several reports have shown SRT to be effective for macular diseases, but there have been no reports to date for macular edema (ME) associated with branch retinal vein occlusion (BRVO). The purpose of this study was thus to compare the efficacy of combination therapy of intravitreal ranibizumab (IVR) and SRT with IVR monotherapy in patients with ME secondary to BRVO.

Methods : This trial was a 12-month single-center, randomized, single-masked prospective study. The SRT laser (Medical Laser Center Lübeck, Germany) applies a train of 30 pulses, each 1.7 µs in duration, with a rate of 100 Hz at a wavelength of 527 nm onto a spot diameter of 200 µm. Eligible patients were randomized (1:1) to IVR with SRT (IVR+SRT group), or IVR with sham SRT (IVR+sham group). After initial IVR, all participants received ME resolution criteria-driven pro re nata treatment. SRT or sham SRT were always applied one day after IVR. Primary outcome measure of this study was mean change in central macular thickness (CMT), and secondary outcome measures were mean change in visual acuity and the number of IVR treatments.

Results : A total number of 24 patients completed the study, among which 13 patients were in IVR+SRT group and 11 in IVR+sham group. Mean CMTs for the IVR+SRT and IVR+sham groups were 534 ± 92 mm and 479 ± 138 mm at baseline, 237 ± 83 mm and 249 ± 78 mm at 52 weeks, respectively, with significant difference between baseline and at 52 weeks for both groups (p < 0.01), but no difference between groups (p = 0.26). Mean BCVA (logMAR) for the IVR+SRT and IVR+sham groups were 0.28 ± 0.14 and 0.32 ± 0.31 at baseline, 0.03 ± 0.13 and 0.13 ± 0.26 at 52 weeks, respectively, with significant difference between baseline and at 52 weeks in both groups (p < 0.01), but no difference between groups (p = 0.10). Mean total number of IVR for the IVR+SRT group was 2.85 ± 1.52 and it was significantly fewer than the one for the IVR+sham group 4.73 ± 2.33 (p < 0.05).

Conclusions : IVR combined with SRT may significantly decrease the number of IVR treatments while maintaining visual and anatomical improvement effect of IVR monotherapy.

This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.