Changes in the foveal microstructure after intravitreal bevacizumab application in patients with retinal vascular disease

Abstract

PurposeTo investigate changes in the area of the foveal avascular zone (FAZ) in patients with retinal vascular disease.Patients and methodsThis retrospective, consecutive study examined 53 eyes of 53 patients with macular edema due to branch retinal vein occlusion in 25 patients (47.2%) and nonproliferative diabetic retinopathy in 28 patients (52.8%). The macular edema was treated with an intravitreal injection of 0.05 mL equal to 1.25 mg bevacizumab. Before and 6–8 weeks after the injection, best corrected visual acuity, slit lamp biomicroscopy of the anterior segment and fundus, optical coherence tomography, and fluorescein angiography were conducted. The FAZ was manually circumscribed on early-phase angiography images and the area of the FAZ was measured.ResultsThe preoperative overall mean FAZ area was 0.327 ± 0.126 mm2 (median 0.310 mm2). At the control consultation, the overall mean area was significantly larger (0.422 ± 0.259 mm2; median 0.380 mm2; P < 0.001). In the nonproliferative diabetic retinopathy subpopulation, the mean area was 0.361 ± 0.129 mm2 (median 0.330 mm2) before bevacizumab application and 0.434 mm2 at the follow-up visit (mean increase 0.071 mm2/19.7%). In the branch retinal vein occlusion group, the baseline FAZ area was 0.290 ± 0.115 mm2 and 0.407 ± 0.350 mm2 at follow-up (median 0.330 mm2; mean increase 0.117 mm2/40.3%). No cases of severe operation-associated complications were observed.ConclusionThe results confirm the safety of intravitreal bevacizumab injection in patients with macular edema due to nonproliferative diabetic retinopathy and branch retinal vein occlusion. The enlargement of the FAZ could be equivalent to an increase in retinal ischemia. These results may be transient; a potential vascular risk, however, when applying antivascular endothelial growth factor therapy in eyes with preexistent vascular disease must be considered.

Changes in Macular Perfusion Detected by Optical Coherence Tomography Angiography Following 3 Intravitreal Monthly Bevacizumab Injections for Diabetic Macular Edema in the IMPACT Study

“…An increase in the FAZ size following intravitreal bevacizumab injections for DME has also been previously reported using FA in several noncomparative studies. 33,34 In one of these studies, there was a 19.7% increase in the FAZ area 6-8 weeks following a single bevacizumab injection for DME, 33 while another study showed a 13% increase in the FAZ area following 3 monthly bevacizumab injections which was greater in patients with milder DR. 34 This was in agreement with our results and could be due to progression of ischemia due to the underlying DR or due to VEGF inhibition or both. 34 Controlled studies are needed to further explain these findings.…”

Retinal Capillary Network and Foveal Avascular Zone in Eyes with Vein Occlusion and Fellow Eyes Analyzed With Optical Coherence Tomography Angiography

“…27,28 Further, foveal microstructure may be altered following anti-VEGF treatment in retinal vascular disease. 29 Future studies that compare treatment-naïve and previously treated eyes with RVO will help determine the effect of anti-VEGF treatment on the observed changes in the retinal microvasculature in this disease.…”

Treatment of Retinal Vein Occlusion with Ranibizumab in Clinical Practice: Longer-Term Results and Predictive Factors of Functional Outcome

“…Measurements of the area of RNP on FA have shown that enlargement of this area is common in both BRVO and CRVO [27,28]. The mechanism is unknown, but concern has been expressed that it may be exacerbated by VEGF itself [1,19], or on the contrary from its inhibition [20,21]. For this purpose, we also analyzed the changes in the FAZ area in eyes with RVO treated with IVR in the long term.…”

“…Few reports exist on this matter in RVO, and none of them evaluated the associated long-term outcomes [17,18]. Also, some debate has been raised about the role of anti-VEGF agents in promoting retinal nonperfusion (RNP) or, on the contrary, in reducing retinal ischemia by promoting retinal reperfusion [1,19,20,21]. The impact of anti-VEGF agents in the choroid is also still poorly understood [22,23].…”