Comparison of detection rates and time costs of different fundus imaging techniques for retinal neovascularization in optic disc and other area of proliferative diabetic retinopathy

Objective

To compare the detection rate and time cost of different imaging methods for retinal and optic disc neovascularization in proliferative diabetic retinopathy (PDR).

Methods

A cross-sectional study was conducted.Thirty-eight patients (48 eyes) with PDR were enrolled in Henan Eye Hospital from October 2019 to February 2021, including 22 males (28 eyes) and 16 females (20 eyes). The average age of the patients was (51.08±13.35) years.All patients underwent ultra-widefield imaging (UWFI), fundus fluorescein angiography (FFA), optical coherence tomography angiography (OCTA), en face optical coherence tomography (OCT), near-infrared fundus imaging (IR) combined with spectral domain OCT (SD-OCT). Wide field swept-source OCTA (WF-SS-OCTA) was performed in the patients who were unsuitable for FFA.The time required for each examination in one eye and the detection rate of neovascularization at the optic disc (NVD) and retinal neovascularization elsewhere (NVE) were recorded.This study adhered to the Declaration of Helsinki.The study protocol was approved by Henan Eye Hospital (No.HNEECKY-2021[22]). All patients were informed about the method and purpose of the study and voluntarily signed the informed consent form.

Results

The mean monocular examination time costs of UWFI, IR+ SD-OCT, OCTA+ en face OCT, FFA and WF-SS-OCT was (0.51±0.13), (2.08±0.57), (5.79±0.68), (17.66±1.83) and (13.38±1.23)min, respectively.There was a significant overall difference in the mean monocular examination time among the five methods (F=2 077.960, P<0.001). The detection rates of UWFI, IR+ SD-OCT, OCTA+ en face OCT, FFA+ WF-SS-OCT for NVE and NVD were 52.1%(25/48) and 12.5%(6/48), 81.3%(39/48) and 20.8%(10/48), 83.3%(40/48) and 27.1%(13/48), 93.8%(45/48) and 29.2%(14/48), respectively.There were significant differences in the detection rates of NVE (χ²=26.460, P<0.001) but not in the detection rates of NVD (χ²=4.645, P=0.200) among the various methods.Five neovascular buds were detected by OCTA in 3 eyes, but not by FFA.

Conclusions

UWFI and IR+ SD-OCT are faster and non-invasive methods for the screening of NVD and NVE in PDR eyes.Compared with FFA, OCTA and en face OCT can show the shape of neovascularization more clearly.FFA provides a wide-range retinal image, but it is time-consuming and invasive.WF-SS-OCTA extends the examination range of OCTA and detects neovascularization non-invasively and faster than FFA.

Diabetic retinopathy/examination; Optical coherence tomography angiography; Fluorescein angiography, fundus; Retinal neovascularization