Optical coherence tomography angiography measured area of retinal neovascularization is predictive of treatment response and progression of disease in patients with proliferative diabetic retinopathy

Abstract

Background The purpose of this study was to evaluate the area of retinal neovascularization in patients with treatment-naïve proliferative diabetic retinopathy (PDR) as measured by optical coherence tomography angiography (OCT-A) as a marker of subsequent treatment response after panretinal photocoagulation (PRP), and to examine if this area correlated with area of retinal neovascularization as measured by fluorescein angiography (FA). Methods En face OCT-A scans (4.5 × 4.5 mm) of neovascularizations were obtained at baseline (BL) before PRP and at month (M) 3 and M6 after treatment. Progression of PDR were defined as lesion growth (assessed by ophthalmoscopy and wide-field fundus photo) or increasing leakage by Optos ultra-widefield FA, and patients were divided into two groups; progression or non-progression. Mann–Whitney U test and Wilcoxon signed-rank test were used to analyse differences between groups and between time points. Areas of retinal neovascularizations (OCT-A and FA) were calculated by algorithms developed in Python (version 3.6.8, The Python Software Foundation, USA). Results Of 21 eyes included, 14 had progression of disease. Median OCT-A area did not differ between the two groups (progression vs. non-progression) at BL (76.40 ± 162.03 vs. 72.62 ± 94.15, p = 0.43) but were statistically significantly larger in the progression group at M6 (276.69 ± 168.78 vs. 61.30 ± 70.90, p = 0.025). Median FA area did not differ in the progression vs. the non-progression group at BL (111.42 ± 143.08 vs. 60.80 ± 54.83, p = 0.05) or at M6 (200.12 ± 91.81 vs. 123.86 ± 162.16, p = 0.62). Intraclass correlation between area by OCT-A and FA was −5.99 (95% CI: −35.28–0.993), p = 0.71. Conclusions In this study of patients with treatment-naïve PDR, we showed that increasing area of retinal neovascularizations measured by OCT-A at M6 indicated progression of disease after PRP treatment. Our results suggest that area by OCT-A reflects disease activity and that it can be used as an indicator to monitor the progression of PDR over time, and to evaluate treatment response six months after PRP. Trial registrationhttps://clinicaltrials.gov (identifier: NCT03113006). Registered April 13, 2017.

Update on Optical Coherence Tomography and Optical Coherence Tomography Angiography Imaging in Proliferative Diabetic Retinopathy

“…UWF-OCTA can also play a role in the anti-VEGF treatment of PDR by providing more supportive information for management decisions at each visit, similar to when treating DME [6,91,99,103]. Specifically, WF-OCTA may be helpful in targeted or conventional panretinal photocoagulation, as previous studies already demonstrated the non-inferiority of extended targeted PRP to conventional PRP in PDR [89][90][91]99,106]. Based on all these results comparing FA and WF-OCTA in detecting PDR, we agree with the adoption of WF-OCTA as a stand-alone imaging modality for diagnosing PDR in clinical practice without the risk of increasing false positives and overtreatment or false negatives and undertreatment [6,41,80,82,[84][85][86]91,97,99,105,106].…”

“…This group proposed a threshold of 40% reduction in both area and vascular perfusion density on OCTA as a possible biomarker for laser efficacy in PDR [89]. Vergmann et al [90] performed similar assessments and concluded that increasing areas of retinal NVCs in OCTA were associated with PDR progression after PRP. This suggests that OCTA reflects disease activity and that it can be used to monitor PDR development and treatment response after PRP.…”

A Paradigm Shift in the Management Approaches of Proliferative Diabetic Retinopathy: Role of Anti-VEGF Therapy

“…Retinal neovascularisation area measured by OCTA has been shown to be predictive of progression in PDR and to evaluate response to treatment following PRP. 99 Papayannis et al introduced an SS-OCTA cortical vitreous segmentation protocol that can be utilised for reproducible detection of neovascularisation and accurate detection of regression activity on follow-up. 100 Pereira et al conducted a comprehensive analysis of 248 studies of OCT and OCTA dine in diabetic retinopathy cases to review recent developments and potential implications of the modalities in clinical settings.…”

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

“…Recently, OCT Angiography (OCTA) has been used to further characterize NV with the aid of flow information additive to the structural OCT image [13][14][15][16][17]. Few studies have analyzed changes of NV in PDR after treatment with OCTA to date, and mainly on a short-term basis [17][18][19][20][21][22][23][24]. Significant advantages of OCTA are the practical repeatability due to its speed and noninvasiveness, the combination of flow information (similar to conventional fluorescein angiography (FA)) and structural information (OCT image), and the possibility of quantitative analysis.…”