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Jordi Mones, Brighter and Crystal; Evaluation of ranibizumab for macular ischemia in retinal vein occlusion: evidence from the BRIGHTER and CRYSTAL studies. Invest. Ophthalmol. Vis. Sci. 2015;56(7 ):5803.
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© ARVO (1962-2015); The Authors (2016-present)
Retinal vein occlusion (RVO) is commonly associated with retinal ischemia, which may have an impact on prognosis and disease management. Whilst interventional RVO studies have typically included assessments of retinal perfusion, the criteria frequently differ between studies. Here, we report the grading criteria for ischemia and the best-corrected visual acuity (BCVA) outcomes based on patient’s baseline ischemic status from the BRIGHTER and CRYSTAL studies.
BRIGHTER and CRYSTAL are two ongoing 24-month (M) studies assessing the long-term efficacy and safety of a stabilization criteria-driven pro re nata ranibizumab 0.5 mg (RBZ) dosing regimen in patients with branch and central RVO (BRVO and CRVO). In BRIGHTER, patients with BRVO (N=455) were randomized (2:2:1) to RBZ (n=183), RBZ+laser (n=180) or laser (n=92) alone. In CRYSTAL, all patients with CRVO (N=357) were assigned to RBZ treatment. In both studies, retinal ischemia (assessed by Central Reading Centre) was defined as capillary loss (mild, moderate, severe or completely destroyed) in at least one location of the center, inner or outer subfield based on Early Treatment Diabetic Retinopathy Study (ETDRS) grading. The endpoint was mean BCVA from baseline to M6 (BRIGHTER) and M12 (CRYSTAL) based on baseline ischemic status.
In BRIGHTER, at baseline for the RBZ, RBZ+laser and laser arms, the mean BCVA was 60.7, 58.7, and 56.8 letters (ischemic) and 60.6, 60.3, and 60.6 letters (non-ischemic), respectively. Ischemia was present in 40-48.1% of patients across treatment groups (Table 1). At M6, significant BCVA gains were observed with RBZ or RBZ+laser vs laser, regardless of ischemic status (ischemic: 74.9 or 73.1 vs 64.7; non-ischemic: 72.5 or 72.2 vs 63.3, Fig.1). In CRYSTAL, 30% of patients had ischemia at baseline and the mean baseline BCVA was 54.5 (ischemic) and 55.5 (non-ischemic) letters. The mean BCVA improved to 66.1 and 67.7 letters at M12 in ischemic and non-ischemic patients, respectively (Fig.1).
The BRIGHTER and CRYSTAL studies demonstrated that the flexible administration of RBZ is an effective therapy for BRVO and CRVO patients regardless of baseline ischemic status. Greater alignment on grading and reporting of retinal perfusion status in clinical studies should be considered.
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