Abstract
Purpose: :
An exploratory analysis of factors affecting treatment response to selective anti-VEGF therapy with pegaptanib in patients with macular edema (ME) secondary to CRVO including eyes losing >3 lines of vision and eyes needing prolonged therapy.
Methods: :
A phase 2, prospective, multicenter, double-masked, dose-finding studyenrolled subjects with ME secondary to CRVO. CRVO must have occurred within 6 months of baseline, with best-corrected visual acuity (VA) in the study eye between 65 and 20 ETDRS letters and central retinal thickness of ≥250 µm; subjects with brisk afferent papillary defect or ocular neovascularization at baseline were excluded. Pegaptanib (0.3 or 1.0 mg) or sham injections were given every 6 weeks for 24 weeks, with the final assessment at week 30. A retrospective review of baseline demographic, clinical and imaging data of subjects who lost ≥3 lines of VA by week 30 or who required additional therapy after week 30 was conducted.
Results: :
Among the 5 pegaptanib subjects who lost ≥3 lines of VA (3 and 2 in the 0.3 and 1.0 mg groups, respectively) all had anatomic improvement at week 1, with an average decrease in center point thickness (CPT) of 405 µm (range: 162-666), but experienced a vascular event (e.g. ischemic transformation, ocular NV or arterial occlusion) that could have resulted in the VA loss. Seventeen pegaptanib subjects needed additional therapy after week 30 (9 in 0.3 and 8 in 1.0 mg groups); 8 had collaterals on the disc at baseline (4 with questionable and 4 with definitive collaterals) and 9 developed them during the study (1 and 8 with questionable and definite collaterals, respectively). Mean changes in both VA and CPT from baseline to week 30 were more pronounced in the subjects who needed additional therapy compared to those who did not.
Conclusions: :
Loss of vision despite reduction in ME with pegaptanib therapy in ME secondary to CRVO was primarily attributed to additional ischemic vascular events. Presence of or the development of collaterals did not seem to prevent the need for prolonged therapy.
Clinical Trial: :
www.clinicaltrials.gov NCT00088283
Keywords: vascular occlusion/vascular occlusive disease • vascular endothelial growth factor