Evaluation of the Effect of Repeated Intravitreal Bevacizumab Injections on the Macular Microvasculature of a Diabetic Patient Using Optical Coherence Tomography Angiography

Abstract

A 53-year-old female patient with center-involving diabetic macular edema affecting the left eye was imaged using optical coherence tomography angiography (OCTA) in both eyes. She underwent three monthly intravitreal bevacizumab injections in the left eye only and OCTA was repeated in both eyes one month following the last injection and showed decreased vascular density (VD) in the treated left eye but not in the untreated right eye compared to baseline. No further injections were required in either eye, and OCTA was done in both eyes 4 months following the last injection which showed improved VD of the left eye with stable VD in the right. Three monthly intravitreal bevacizumab injections were then required in both eyes; then OCTA was repeated following the last injection and revealed decreased VD in both eyes compared to previous scan. OCTA could be a useful tool for detecting VD changes following bevacizumab injections in diabetics.

Figures

Figure 1

Fundus photography and fluorescein angiography of both eyes. Fundus photography showed retinal hemorrhages affecting the posterior pole in both eyes with clinically significant macular edema in the left eye (a and b). Fluorescein angiography revealed microaneurysms and areas of blocked fluorescence due to retinal hemorrhages in both eyes with leakage of fluorescein in the left macula (c and d).

Figure 2

Structural OCT of the left macula. (a) At presentation, there were multiple intraretinal cystic spaces with mild subfoveal neurosensory detachment and diffuse retinal thickening. (b) Following 3 monthly intravitreal bevacizumab injections, there was improvement of the retinal edema and neurosensory detachment. (c) Follow-up 4 months following the last injection showed increased intraretinal cystic spaces and retinal thickness with recurrence of neurosensory detachment. (d) Following another 3 intravitreal injections, there was improvement of the neurosensory detachment and retinal thickness.

Figure 3

OCTA of the SCP of the right (top row) and left (bottom row) maculae. At presentation, there were areas of capillary nonperfusion detected in the SCP of both eyes especially temporally (a and e). Following three months of no intervention in the right eye and three monthly intravitreal injections in the left eye, there was increased vascular density (VD) in the right eye (b) and decreased VD in the left (f). After four months of no interventions in either eye, there was no change in the VD in the right eye (c) and increased VD in the left (g). Finally, following three monthly intravitreal injections in both eyes, there was decreased VD in both eyes (d and h). Scan quality was 6/10 or higher in all images and there were no significant segmentation errors detected. Whole image vascular density (WIVD), as measured by the built-in machine software, is shown at each visit.