Ranibizumab improves vision of eyes with diabetic macular oedema, macular nonperfusion
Treatment with ranibizumab has resulted in robust visual acuity and anatomic improvement in eyes with concurrent diabetic macular oedema (DME) and baseline macular nonperfusion (MNP) despite having worse vision or increased central subfield thickness (CST), according to a posthoc analysis of RIDE and RISE, two phase III randomized controlled trials.
Eyes with best-corrected visual acuity (BCVA) or fluorescein angiogram (FA) data at baseline were included in this study. Researchers measured MNP by overlaying the Early Treatment for Diabetic Retinopathy Study (ETDRS) grid on FAs of the macula. They calculated the MNP area by estimating the percentage of capillary loss in the central, inner and outer subfields and converting into disc areas using a software algorithm.
Measured outcomes were as follows: baseline characteristics, MNP area, BCVA and CST at months 12 and 24, and incidence of study eyes with ≥2-step diabetic retinopathy improvement at months 3, 6, 12, 18 and 24.
Baseline MNP was detected in 213 (28.2 percent) of study eyes in the ranibizumab 0.3-mg arm, 225 (25.8 percent) in the ranibizumab 0.5-mg arm and 228 (26.3 percent) in the sham arm. The following characteristics were identified in patients with MNP at baseline: younger age, shorter diabetes duration, worse vision, increased CST and worse DR severity (p<0.01 vs those without MNP). [Ophthalmology 2018;125:1568-1574]
Eyes with baseline MNP in the ranibizumab 0.3-mg arm had lower mean baseline BCVA compared to those without baseline MNP (53.4 vs 57.2 ETDRS letters; p=0.05). However, mean BCVA gain at month 24 were similar between the two groups (15.6 vs 13.4 ETDRS letters; p=0.2).
CST was elevated in eyes with baseline MNP, but this was significantly reduced by month 24. In each ranibizumab arm, more eyes with vs without baseline MNP had ≥2-step DR improvement.
“In a previously published analysis that explored MNP in patients with DME from RIDE and RISE, Campochiaro [and colleagues] used the same definition of MNP as this analysis. Their focus was on whether monthly RBZ reduced the progression of MNP rather than on vision outcomes in patients with MNP at baseline,” researchers said. [Ophthalmology 2014;121:1783-1789]
Most patients in the said analysis had no MNP at baseline (73.5 percent in the sham arm vs 71.8 percent and 74.2 percent in the ranibizumab 0.3- and 0.5-mg groups, respectively). In the present analysis, the percentage of patients with MNP at baseline, month 12 and month 24, respectively, was relatively stable in the ranibizumab 0.3-mg (28 percent, 22 percent and 25 percent) and ranibizumab 0.5-mg arms (27 percent, 19 percent and 25 percent), but increased in the sham arm (26 percent, 35 percent and 43 percent). [Ophthalmology 2014;121:1783-1789]
Furthermore, no significant differences were observed in the efficacy of ranibizumab between patients with and without MNP at baseline within the scope of RIDE and RISE.
“Overall, these data contradict the belief that anti-VEGF (vascular endothelial growth factor) treatment will exacerbate MNP and instead support the commencement and continued use of ranibizumab as an effective treatment for patients presenting with DME and MNP, because they have the potential to benefit from [such] treatment and therefore should not be excluded from therapy,” researchers said.