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Updated: Aug 26, 2025

An Alternative and Validated Injection Method for Accessing the Subretinal Space via a Transcleral Posterior Approach
Published on: December 7, 2016
Three Monthly Injections Versus One Initial Injection of Ranibizumab for the Treatment of Macular Edema Secondary to
Wenyi Tang1,2,3, Jingli Guo4, Gezhi Xu1,2,3
1Department of Ophthalmology, Eye and ENT Hospital of Fudan University, 83 Fenyang Road, Shanghai, 200031, China.
Introduction:
To compare three monthly injections versus one initial injection of intravitreal ranibizumab (IVR) followed by pro re nata (PRN) dosing to treat macular edema secondary to branch retinal vein occlusion (BRVO).
Methods:
Seventy-four patients were randomized (1:1) to the 3 + PRN or 1 + PRN groups. Patients underwent monthly evaluations and additional IVR injections were administered if the retreatment criteria were met. The functional and anatomical outcomes were recorded. The factors associated with the improvement in best-corrected visual acuity (BCVA) were analyzed.
Results:
Sixty-nine patients (93.2%) completed the study. At 12 months, the mean gain in BCVA was 12.9 letters in the 3 + PRN group and 14.3 letters in the 1 + PRN group, which was not significant (P = 0.59). The mean reduction in central macular thickness was 297.8 μm in the 3 + PRN group and 300.2 μm in the 1 + PRN group (P = 0.96). The macular vascular density changes of the superficial and deep capillary plexuses were not significantly different between the two groups (P = 0.99 and 0.70, respectively). The mean number of IVR injections was 5.0 in the 3 + PRN group and 4.2 in the 1 + PRN group (P = 0.17). The incidence of retinal neovascularization was similar in both groups (P = 0.67). The baseline BCVA, but not the treatment regimen, was significantly associated with the change in BCVA (P < 0.01).
Conclusion:
Significant gains in BCVA and maintenance of macular perfusion were achieved in BRVO eyes treated with the 3 + PRN or 1 + PRN regimens. Baseline BCVA was a prognostic factor for the visual improvement.
Trial Registration:
A prospective randomized controlled trial to compare the 1 + PRN and 3 + PRN regimen in the treatment of macular edema secondary to branch retinal vein occlusion (ChiCTR2000038086).
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