Wide-field swept-source optical coherence tomography angiography (SS OCT-A) can help physicians confirm clinically relevant features of diabetic tractional retinal detachments in patients with diabetic retinopathy before and after pars plana vitrectomy, according to study findings published in Retina.
Due to the fragility of ischemic retina and fibrovascular membranes, surgical repair of tractional retinal detachments remains one of the most technically challenging surgeries in ophthalmology. Fluorescein angiography is typically used to assess retinal ischemia, however, it is time consuming and requires intravenous access, which is not optimal for patients with severe diabetes. In addition, fluorescein angiography is time consuming and may not provide clear margins between fibrovascular membranes and their elevation from the retinal surface, according to the study.
Investigators conducted a prospective, observational study to review the use of wide-field SS OCT-A to characterize diabetic tractional retinal detachments before and after surgery.
A total of 31 eyes with diabetic tractional retinal detachments from 21 patients (mean age, 49.3 years) were included in the study. The majority (76%) of patients had type 2 diabetes. The average level of glycated hemoglobin among the 71% of patients with recent readings was 8.8. Of the 31 eyes, 39% underwent SS OCT-A but not surgery, and 61% underwent surgery; 7 eyes had preoperative media opacity or poor fixation that precluded preoperative SS OCT-A, and 2 eyes were lost to follow-up before postoperative imaging.
Among the 10 eyes that underwent both pre- and postoperative evaluation, the mean interval to postoperative imaging was 4.6 months after surgery.
At baseline, retinal topography was depicted throughout the posterior pole with en face depth-encoded wide-field SS OCT-A, which allowed for rapid evaluation of retinal traction and tractional retinal detachment. The findings were consistent with those from fundus examination and ultrawide field imaging.
In contrast, WF SS OCT-A scans taken postoperatively were able to show areas of retinal nonperfusion in places where retinal vessels were not visible preoperatively due to overlying neovascularization. On postoperative imaging, enlargement or increased capillary dropout was not seen in areas of retinal ischemia that were visible preoperatively. Areas that were fully perfused preoperatively did not become ischemic postoperatively.
“Current SS OCT-A instruments are limited by poor fixation or severe media opacity,” the investigators note. “Because of this, we were unable to obtain high-quality preoperative SS OCT-A images in diabetic [tractional retinal detachment] eyes with preoperative [best-corrected visual acuity] worse than 20/400 and/or with dense cataract or [vitreous hemorrhage].”
“Retinal perfusion did not change appreciably after [pars plana vitrectomy] for these eyes with diabetic [tractional retinal detachment]. For posterior pole disease, if the media are clear and fixation is adequate, [wide-field] SS OCT-A is likely the only imaging modality needed for the diagnosis and longitudinal evaluation of diabetic [tractional retinal detachments] and may be useful to guide surgical decision making and postoperative management,” report the investigators.
Disclosure: Multiple study authors declared affiliations with the biotech, pharmaceutical, and/or device companies. This research was supported by Carl Zeiss Meditec, Inc. Please see the original reference for a full list of authors’ disclosures.
Russell JF, Scott NL, Townsend JH, et al. Wide-field swept-source optical coherence tomography angiography of diabetic tractional retinal detachments before and after surgical repair. Retina. 2021;41(8):1587-1596. doi:10.1097/IAE.0000000000003146