Abstract
Purpose: :
To develop and validate a method of predicting at one month post–intravitreous injection whether subjects receiving Vitrase® (lyophilized ovine hyaluronidase for injection) will achieve at least a three–line improvement in best corrected visual acuity (BCVA) without vitrectomy by three months post–intravitreous injection.
Methods: :
A statistical training set drawn from subjects with diabetes mellitus (N = 269 of 812) 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 at least a 3–line BCVA improvement by three months without vitrectomy. THPS was compared for subjects in the saline, 55 IU and 75 IU Vitrase treatment groups.
Results: :
For the ROC analysis, the area under the curve was 0.676 (p <0.0001), indicating high predictive value. Subjects in the 55 IU and 75 IU Vitrase groups had considerably greater median improvement in THPS at one month compared with 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), which allows prediction of BCVA by 3 months.
Conclusions: :
The change in a relatively simple measurement for the density of vitreous hemorrhage, THPS, by one month post– intravitreous injection of Vitrase, allows prediction of treatment success as measured by BCVA at 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, since it provides evaluative information by one month post–injection.
Keywords: diabetic retinopathy • injection • vitreous