Abstract
Purpose:
Diabetic macular edema (DME) is often treated with the delivery of anti-VEGF agents through intravitreal injection creating a reservoir of the drug in the vitreous cavity. Previous studies have shown that intravitreal injections may increase the rate of formation of PVD. However, the effect of a posterior vitreous detachment (PVD) on the response to anti-VEGF therapy is yet unknown. This study seeks to address this issue.
Methods:
We identified 61 patients with a total of 77 eyes receiving treatment for diabetic macular edema with bevacizumab between 2008-2012 at a single university-based county hospital. Retrospective review of serial Stratus OCT imaging of the macula and patient charts was performed to determine the position of the posterior hyaloid face and patient response to treatment by visual acuity and change in central macular thickness.
Results:
The posterior hyaloid face could be definitively identified at baseline in 13 eyes (16.8%). Five of these 13 eyes (6.4% of all enrolled eyes) showed progression of PVD during the course of treatment with intravitreal bevacizumab injections as evidenced by increased distance of the hyaloid face from the macula (mean 0.34mm after mean of 2.4 injections) on OCT imaging, however, in 2 of these cases the posterior hyaloid face appeared to have moved beyond the range of the imaged area as time-domain OCT provides an image with depth of 2mm and inferior quality to spectral-domain OCT.
Conclusions:
Some eyes receiving intravitreal injections demonstrated a progression of posterior vitreous detachment (PVD), however with this small sample size no conclusions could be drawn regarding the effect of PVD on response of diabetic macular edema to anti-VEGF therapy. One limitation to time-domain OCT is the inability to identify the posterior hyaloid face in all cases. Further studies to examine this effect using spectral-domain OCT imaging in conjunction with more objective clinical and B-scan evidence of a PVD are underway.
Keywords: 763 vitreous •
499 diabetic retinopathy •
561 injection