Comparison of two individualized treatment regimens with ranibizumab for diabetic macular edema.

Purpose: To compare outcomes between an as-needed and a treat-and-extend regimen in managing diabetic macular edema with intravitreal ranibizumab.

Methods: This was a retrospective, single-centre, comparative case series on 46 treatment naive patients with diabetic macular edema. Twenty-two patients were treated following an optical coherence tomography guided treat-and-extend protocol (OCTER), and 24 patients were treated according to a visual acuity guided pro re nata regimen (VAPRN) at a tertiarry referral centre. The main outcome measures were best-corrected visual acuity, central retinal thickness, and the number of ranibizumab injections, as well as visits after 12 months of treatment.

Results: After 12 months, the mean gain in best-corrected visual acuity (± standard deviation) was 8.3 ± 6.7 versus 9.3 ± 8.9 letters in the VAPRN and OCTER group, respectively (p = 0.3). The mean decrease in central retinal thickness was 68.1 ± 88.0 μm in the VAPRN group and 117.6 ± 114.4 μm in the OCTER group (p = 0.2). The mean number of ranibizumab injections was significantly different between the VAPRN (5.9 ± 1.8) and the OCTER protocol (8.9 ± 2.0) (p < 0.001).

Conclusion: The visual acuity driven retreatment regimen resulted in a similar visual acuity outcome like optical coherence tomography guided retreatment for diabetic macular edema. Although the number of visits was similar in both groups, patients in the VAPRN group received significantly fewer intravitreal injections than patients in the OCTER group.