B-Scan ultrasonography of vitreous dynamics during intravitreal administration of antiangiogenics

Abstract

Purpose: To study the distribution of angiogenesis inhibitors (anti-Vascular Endothelial Growth Factor) injected into the vitreous cavity by means of simultaneous ultrasonography. Methods: Three hundred and thirty-two B-scan ultrasound sequences of 121 eyes from 95 patients were recorded simultaneously to the intravitreal anti-Vascular Endothelial Growth Factor administration. The dynamics of the injected substance and the presence of reflux were studied, associating them with the presence/absence of total posterior vitreous detachment.

Results: Three well-defined patterns were distinguished. Pattern A: the medication penetrates the vitreous in a linear manner until reaching the retina (3.6%, n = 12). Pattern B: the medication adopts a globular shape and then moves down reaching the retrohyaloid space (37%, n = 123). Pattern C: the medication remains in a globular form (54%, n = 180). The pattern was not identified in 17 (5.1%) injections. Pattern A was only observed in vitrectomized eyes. The reflux (7.8%) was exclusive in eyes showing a C pattern. A relationship (P < 0.001) was observed between the presence/absence of total posterior vitreous detachment, the patterns, and the presence of reflux. Conclusion: This study document for the first time the behavior of antiangiogenic medication injected into the vitreous cavity and how its distribution and the presence of reflux is conditioned by the previous state of the vitreous body.