Author: Pasquale Viggiano (Italy)
Co-authors: Pasquale Viggiano, Eliana Costanzo, Daniela Giannini, Serena Fragiotta, Daniele De Geronimo, Mariacristina Parravano
To explore the potential relationships between macular vascular network and different adaptive optics (AO) metrics in patients with type 1 diabetes mellitus with no or early signs of non proliferative diabetic retinopathy (NPDR).
observational cross-sectional study
Consecutive DM1 patients with no or early signs of NPDR and healthy age matched control subjects were enrolled at the Department of Ophthalmology of IRCCS-Fondazione Bietti, Rome. All patients and controls were imaged by using AO retinal camera (rtx1; Imagine Eyes, Orsay, France) and PLEX Elite 9000 OCT angiography (OCTA, Carl Zeiss Meditec Inc., Dublin, CA, USA). The main AO outcome measures to evaluate cone mosaic characteristics were: i) Cone density (CD), ii) linear dispension index (LDi), and iii) heterogeneity packing index (HPi). The main OCTA outcome measures were: i) SCP perfusion (PD) and vessel length densities (VLD) (ii) DCP PD and VLD (iii) SCP and DCP vessel diameter index (VDI) (iv) the CC flow deficit (FD).
The multiple regression analysis revealed that the NPDR group was characterized by a close relationship between cone metrics and CC FD. Notably, there was a positive relationship between FD and LDi (P= .035). On the contrary, a negative relationship was found between FD with both the CD (P= .042) and the HPi (P= .017). The OCTA parameters for retinal circulation, including PD and VLD, displayed a significant negative correlation with CD. In the analysis investigating the parafoveal subfields, the NPDR temporal sector was characterized by a higher negative correlation between AO metrics and OCTA variables.
In conclusion, using a combination of SS-OCTA and AO, our study assessed the relationship between macular perfusion (both retinal and choroidal) and AO metrics in patients with DM1 diabetes. In particular, in NPDR eyes photoreceptor damage was strongly associated with choriocapillaris insufficiency even in the early stage of the disease.