Abstract
Purpose: :
To develop and validate a method of predicting by one month post–intravitreous injection whether subjects receiving Vitrase® (lyophilized, ovine hyaluronidase for injection), will receive adequate laser photocoagulation without vitrectomy by three months post–injection.
Methods: :
A statistical training set drawn from subjects with diabetes mellitus (N = 350 of 813) from the Vitrase for Vitreous Hemorrhage phase III clinical trials was retrospectively analyzed. At baseline and at one month post–injection, vitreous hemorrhage density was scored on a well–defined 0–4 scale, in each of twelve radial segments within the eye ("clock hours"). Using receiver–operating–characteristic (ROC) analysis, the change in the sum of the twelve measurements ("Total Hemorrhage Point Score", THPS) was evaluated as a predictor of treatment success, defined as completion of panretinal laser photocoagulation (at least 6 clock hours for subjects with PDR or 3 clock hours for subjects with BRVO) by three months without vitrectomy. THPS was compared for treatment groups receiving injections of saline, 55 IU and 75 IU Vitrase.
Results: :
For the ROC analysis, the area under the curve was 0.865 (p <0.0001), indicating high predictive value. Subjects in the 55 IU and 75 IU Vitrase treatment groups had considerably greater median improvement in THPS at one month compared to saline (8.0 and 6.0 vs. 2.0, p < 0.0001 and p = 0.0003, respectively by the one–sided Wilcoxon rank–sum test), with corresponding trends in completion of laser among the three groups.
Conclusions: :
The change in a relatively simple measurement of the density of vitreous hemorrhage, THPS, by one month post–intravitreous injection of Vitrase, allows prediction of treatment success, defined using diagnosis–based criteria for the amount of panretinal laser photocoagulation completed by three months. Subjects with diabetes who were treated with Vitrase had significantly higher predicted success rates than subjects treated with saline. This finding can allow physicians to more effectively manage patients with vitreous hemorrhage treated with Vitrase by one month post–injection.
Keywords: diabetic retinopathy • injection • vitreous