Author: Omar Ayedi (Tunisia)
Co-authors: Imen Kaibi, Mouna Rekik, Salma Gargouri, Kmar Maaloul, Dorra Sellami, Amira Trigui
Purpose
To examine and compare choroidal thickness (CT) profiles between patients with type 2 diabetes (T2D) and healthy controls based on swept source-optical coherence tomography (SS-OCT).
Setting/Venue
This prospective observational cross-sectional study was conducted at department of ophthalmology, Habib-Bourguiba University Hospital, Sfax, Tunisia. The study included 258 eyes of 151 patients followed between Mars 3, 2020, and September 28, 2020.
Methods
188 eyes of 112 T2D patients (101 with no diabetic retinopathy [NDR], 87 with different stages of diabetic retinopathy [DR]), and 70 eyes of 39 control subjects were enrolled. A macular 7 * 7 mm cube, with 256 horizontal B-scans, was scanned with SS-OCT. Segmentation of choroid was performed automatically using the segmentation algorithm of the OCT device. Three-dimensional maps were created to represent the choroid. The scanned area was divided into 9 different zones. CT of equivalent zones were compared between groups.
Results
258 CT maps were analyzed. Mean age (standard deviation) was 54.17 (± 9.12). All groups were similar regarding the prevalence of coexisting hypertension and dyslipidemia (P = 0.860 and 0.248 respectively) and regarding the sex ratio (P = 0.818). The CT pattern was similar in all the groups. The peri-foveal choroid was significantly thinner than the para-foveal choroid. The external nasal choroid was thinner than the others subfields NDR and DR groups presented a lower CT than control eyes in all ETDRS subfields (mean CT was 232.17 ± 49.24 µm in healthy controls, 203.56 ± 58.98 µm in NDR patients and 192.65 ± 59.84 in DR patients ; p=0.000). When comparing the severe NPDR to PDR group and the mild to moderate DR group, CT was reduced in the nine ETDRS sectors. Considering the presence of DME within the DR group, we detected no differences (p>0.05) in the CT between DME and non-DME patients for the nine ETDRS sectors. After adjusting for age, gender, spherical equivalent and inter-eye dependence on a multivariate analysis; central, para-foveal and peri-foveal CTs in the NDR and DR groups maintained a statistically significant difference from the control group.
Conlusions
The choroidal maps showed an overall decrease of CT in diabetic eyes even in the absence of biomicroscopic evidence of DR. CT thinning was independent of the severity of the DR and the presence of DME. The findings indicate that in diabetic eyes, choroidopathy is disease rather than retinal vasculopathy dependent. Additional investigation into the effect of diabetes on the choroid is recommended.
Financial Disclosure
-
Comments
-
