Clinical assessment and relationship of retinal fluorophores and microvascular modifications in early diabetic retinal disease in type 1 diabetes
Stela Vujosevic, Caterina Toma, Elisa Cipponeri, Gabriele Piccoli, Vanda Bucceri, Luigi Brotto, Sofia Ginelli, Simone Caboni, Chiara Rui, Enea Poletti, Marco Brambilla, Emanuele Torti, Stefano De Cillà, Livio Luzi, Paolo NucciPurpose:
To quantify macular microvascular modifications and retinal fluorophores in early diabetic retinal disease (DRD) in type 1 diabetes mellitus (DM1), and to explore their interrelationship.
Methods:
One-hundred twenty-one subjects with DM1 and no diabetic retinopathy (noDR) or mild/moderate non-proliferative DR (NPDR) underwent optical coherence tomography (OCT), OCT-angiography (OCT-A), and spectrally resolved fundus autofluorescence (Sr-FAF). OCT-A was analyzed for perfusion/vessel density (PD/VD), fractal dimension (FD), vessel length density (VLD), geometric perfusion deficits (GPD), and foveal avascular zone metrics in the superficial and deep capillary plexuses (SCP/DCP). Sr-FAF green and red emission fluorescence component (GEFC/REFC) intensities in 9 ETDRS macular sectors were quantified. Mann-Whitney U test was used for group comparisons and Pearson’s coefficients for correlations between OCT-A and Sr-FAF.
Results:
One-hundred four eyes (50 noDR, 54 NPDR) were included. NPDR eyes showed lower PD, VD, FD, and VLD and higher GPD (p<0.001) in DCP vs noDR. GEFC intensity was higher in NPDR vs noDR in the nasal (p<0.01) and inner inferior (p=0.009) sectors and in the whole macular region(p=0.04); REFC intensity was higher in NPDR vs noDR at the fovea and in the inner nasal sector (p=0.01). In NPDR, DCP perfusion metrics correlated positively with GEFC and REFC values; in noDR, weak negative correlations were documented.
Conclusions:
Quantification of minor retinal fluorophores with Sr-FAF and microvascular assessment may provide novel insights into early DRD in DM1. Opposing correlation trends across disease stages suggest dynamic vascular-metabolic interactions. Sr-FAF may serve as a biomarker of retinal metabolic status, warranting further validation.