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According to 3x3 mm and 6x6 mm OCTA scans, there were no significant changes in mean macular intercapillary area measures for all tested regions.
A new study found that 3-6 consecutive monthly injections of anti-VEGFs for diabetic macular edema (DME) were not associated with significant changes in macular intercapillary area (ICA).
An investigative team, led Osama Sorour, MD, of Tufts University, conducted a multicenter retrospective study where they collected 6x6 and 3x3 mm OCTA images from DME patients treated with anti-VEGF injections.
“Recent reports suggest that intercapillary area is a valid OCTA metric that is more sensitive than vessel-based metrics like vessel density in quantifying retinal ischemia,” they wrote.
“In this study, the effect of repeated anti-VEGF injections on macular perfusion in DME eyes using ICA was evaluated."
Sorour and team enrolled treatment naive patients with either type 1 or type 2 diabetes. Further, all patients had received at least 3 monthly consecutive intravitreal injections of anti-VEGFs.
The investigators then collected medical histories from chart reviews, including type of diabetes, duration of diabetes diagnosis, insulin or medical management, the most recently measured HbA1c, as well as diagnosis of associated hypertension.
Ophthalmology data from examinations and color fundus photography were recorded at clinic visit.
“Measurements were done in concentric regions centered on the fovea—with the exclusion of foveal avascular zone (FAZ)—in 0.5 mm diameter increments as well as within the intervening rings,” they wrote.
They quantified the changes in ICA post-treatment using MATLAB software to process the en-face OCTA images.
As such, 6x6 mm OCTA images were gathered from 46 eyes representing 29 patients, and 3x3 mm images were collected from 23 eyes of 15 patients. The mean age of the population was 58.2 years.
According to pre- and post-treatment assessments, 3x3 mm and 6x6 OCTA scans revealed no significant change in mean ICA measures for all tested regions.
“There was no association between baseline mean ICA in any measurement region from 6x6 mm OCTA scans with patients' sex, HbA1c level, diabetes type, the treatment method (insulin or hypoglycemic drugs), diabetic retinopathy severity grade, and associated hypertension,” Sorour’s team reported.
“However, there was a significant association between [diabetes mellitus] duration and ICA at the inner 1 mm circle surrounding the FAZ (P = .018).”
They also noted an association between age and pre-treatment measurements in 5, 5.5 mm circles, as well as similar outer rings. Pre- and post-treatment BCVA was also associated with ICA in some measurements, while pre-treatment central retinal thickness measurements were not associated with baseline mean ICA measurements.
According to multivariate analysis, baseline BCVA was significantly correlated with the visual outcome (P = .039).
Following adjustment for age, baseline central retinal thickness, baseline BCVA, and retinopathy severity, the investigators found that mean ICA in the 1.5 mm circle was a strong predictor of of post-treatment central retinal thickness (P = .006).
“This suggests that anti-VEGF drugs do not impair macular circulation, and these drugs can be used in patients with pre-existing macular non-perfusion without exacerbation of the non-perfusion,” Sorour and colleagues wrote.
“However, further prospective studies with more prolonged longitudinal follow up and the use of wide field OCTA are necessary to confirm our results and to rule out the progression of ischemia in more peripheral regions," they indicated.
The study, “Mean macular intercapillary area in eyes with diabetic macular oedema after anti-VEGF therapy and its association with treatment response,” was published online in Clinical & Experimental Ophthalmology.