Randomized study evaluating the efficacy of sustained-release dexamethasone with or without prompt laser for branch retinal vein occlusion-related macular edema.

Abstract

Purpose: To evaluate the combination therapy of sustained-release dexamethasone implant (DI) with/without prompt laser in patients with macular edema secondary to BRVO.

Methods: Forty eyes of 40 patients with BRVO were randomized into two groups. Group 1 received a single dose of intravitreal injection of DI, and Group 2 received a single dose of DI followed by prompt laser treatment on the 7th day. Primarily, outcome measures noted at 3, 6, 9, and 12 months' follow-up were improvement in best-corrected visual acuity (BCVA) and central macular thickness (CMT). Secondary outcome measures were change in intraocular pressure (IOP), color vision (CV), and contrast sensitivity (CS).

Results: Mean age of patients in Groups 1 and 2 was 60.30 + 11.59 years and 52.30 + 10.86, respectively. Mean BCVA (logMAR units) in Groups 1 vs. 2 was 0.72 vs. 0.67 at baseline (p=0.286), 0.38 vs. 0.34 at 3 months (p=0.99), 0.29 vs. 0.36 at 6 months (p=0.006), 0.23 vs. 0.36 at 9 months (p=0.001), and 0.19 vs. 0.38 at 12 months (p=0.001), respectively. Mean CMT (μ) in Groups 1 and 2 was 519.5 and 491.1 at baseline (p=0.33), 285.8 and 334.2 at 3 months (p=0.035), 343.1 and 328.9 at 6 months (p=0.294), 309.6 and 328.7 at 9 months (p=0.009), and 283.4 and 316.42 at 12 months (p=0.231), respectively. CS and CV were significantly better in Group 1 as compared to Group 2 at 12 months, while IOP was similar.

Discussion: Our study demonstrated that prompt addition of laser therapy to sustained-release dexamethasone implant did not confer additional benefit in BRVO-related macular edema and might, in fact, compromise long-term visual outcomes. While both groups showed comparable early improvement, monotherapy with dexamethasone resulted in superior BCVA, color vision, and contrast sensitivity at 12 months. These findings suggested that concurrent use of steroids and prompt laser might interfere with retinal healing. Differences in outcomes compared to earlier studies might relate to the timing of laser application, as deferred laser appears to be more effective. Larger trials with longer follow-up are warranted to confirm these observations.

Conclusion: Combination therapy of laser with intravitreal sustained-release DI leads to poorer visual outcomes and may indicate a negative impact of steroid therapy on healing.