Abstract
Purpose :
Emerging evidence indicates that macular optical coherence tomography angiography (OCTA) fractal parameters are related to the presence of peripheral retinal non-perfusion areas (NPAs), on fluorescein angiography (FA), in numerous retinal diseases.
Therefore, the aim of the present study was to evaluate macular OCTA fractal parameters, such Fractal dimension (FD) and Lacunarity (LAC), in treatment naïve DME, in order to investigate their correlation with the presence of peripheral retinal NPAs, on FA.
Methods :
This was a multicenter prospective observational study based on a pool of treatment-naïve DME eyes enrolled at 7 high-volume referral centers, members of the FOVEA study group, between February 2017 and March 2018.
All patients underwent an extensive ophthalmic examination and retinal imaging, including measurement of best corrected visual acuity (BCVA) using Early Treatment Diabetic Retinopathy Study (ETDRS) charts, spectral-domain OCT (SD-OCT; Spectralis; Heidelberg Engineering, Heidelberg, Germany) and FA (Spectralis HRA + OCT; Heidelberg Engineering, Heidelberg, Germany). FA was performed using a 55° lens for the detection of retinal peripheral NPAs in the 4 peripheral quadrants (superior, inferior, nasal and temporal). Macular OCTA images of superficial and deep capillary plexuses (SCP and DCP) were obtained using the in-built software of SD-OCTA (SP-X2001 Update 3, based on Heyex Software Version 1.9.215.0H, Heidelberg Engineering, Heidelberg, Germany). Thereafter, SCP and DCP macular slabs were exported into a previously validated software in order to estimate fractal parameters such as FD and LAC.
Results :
Fifty eyes of 50 DME patients were included in the present study. Thirty (60%) eyes with FA evidence of peripheral retinal NPAs in at least one quadrant showed significantly lower FD and higher LAC in both SCP and DCP, when compared with eyes presenting a well-perfused peripheral retina. Furthermore, macular FD and LAC values of both SCP and DCP were found to be significantly associated to the extent of retinal NPAs (all p<0.05).
Conclusions :
Macular FD and LAC of both SCP and DCP seem to be strongly associated to the extent of peripheral retinal NPAs, thus suggesting that may be useful predictive biomarkers of peripheral ischemia in treatment-naïve DME eyes.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.