Objective Evaluation of Proliferative Diabetic Retinopathy Using OCT

Abstract

To present the routine use of optical coherence tomography (OCT) and OCT angiography (OCTA) for the objective diagnosis and monitoring of proliferative diabetic retinopathy (PDR).Design: Retrospective observational case series. Subjects:Patients with diabetic retinopathy imaged using a standardized PDR-protocol Methods: Patients routinely imaged with a standardized PDR-protocol between March 2017 and January 2019 were included. This included a 12x9 mm structural OCT volume centered on the macula and a 6x6 mm OCTA scan centered on the optic nerve head obtained using a Topcon swept-source system (DRI OCT-1 Triton, Topcon, Tokyo, Japan). Ultra-widefield fluorescein angiography (FA) was also performed when clinically indicated. The ground truth for each case was determined by merging the findings from biomicroscopy and imaging modalities to generate the maximum level of detection for each finding.Main outcome measures: Detection rates of new-onset, regression and reactivation of neovascularization of the disc (NVD) and neovascularization elsewhere (NVE) using different modalities (biomicroscopy/color photography, structural OCT, B-scan OCTA, en face OCTA). Detection of progression of tractional retinal detachment (TRD).Results: 383 eyes of 204 patients were evaluated. After excluding patients without PDR or with insufficient image quality, 47 eyes of 35 patients were included. For the detection of new-onset NVD and NVE, structural OCT had the highest detection rate (100%) of all modalities. However, for the detection of regression or reactivation of neovascularization, B-scan OCTA had the highest detection rate (100%), as structural OCT detected regression only in 45.5% of cases, resulting in a low detection rate of reactivation (12.5%). Among 10 eyes with TRD, OCT detected fovea-threatening TRD during follow-up in 7 eyes, resulting in vitrectomy. Conclusion:This study demonstrates the utility of novel multimodal imaging in the daily management of patients with PDR. Posterior pole structural OCT had the best detection rate for neovascularization, while B-scan OCTA showed the most potential for objective monitoring of disease following treatment.

Diabetic retinopathy and diabetic macular oedema pathways and management: UK Consensus Working Group

“…Most NVE and NVD will be detected on careful clinical examination and are usually clearly visible on FFA. OCT examination can also be very helpful to determine if NV are present (at the posterior pole, where such imaging is possible) in doubtful cases by the presence of pre-retinal hyperreflective material [188]. OCT-A can also be very helpful in assessing areas of capillary non-perfusion and show flow within the new vessels.…”

Widefield optical coherence tomography angiography for early detection and objective evaluation of proliferative diabetic retinopathy

“…The highest rate of detection of NVDs was on OCT (100%), as expected given its highest detection rate, as we have previously shown. (18) This was followed by B-scan OCTA (79.5%), en face OCTA (71,8%), and clinical examination (51.3%). Interestingly, the different NVD anatomical subtypes detected on OCTA can explain the lower detection rate on fundoscopy, as we found that most of the clinically undetectable NVD resulted from subtypes 1 and 2.…”

Characterizing Flow and Structure of Diabetic Retinal Neovascularization after Intravitreal Anti-VEGF Using Optical Coherence Tomography Angiography: A Pilot Study

“…ese studies in principle have highlighted the comparability of OCTA with ultrawidefield FA in diagnosis and follow-up of PDR. On the other hand, Schwartz et al have found B-Scan OCTA to be the most sensitive tool assessing detection rate in NV reactivation [31]. ese results highlight the importance of taking into account both planes-en face and B-Scans when using OCTA for follow-up measurements of NV.…”