Evaluation of Choroidal Thickness in Type 2 Diabetes Using Spectral-Domain Optical Coherence Tomography

Area of Science:

• Ophthalmology
• Endocrinology
• Medical Imaging

Background:

• Diabetic mellitus (DM) causes microvascular changes, leading to diabetic retinopathy (DR) and choroidopathy.
• Limited evidence exists on the relationship between diabetic retinopathy (DR) and choroidal thickness (CT).
• This study investigates the link between DR and CT in diabetic patients.

Purpose of the Study:

• To compare choroidal thickness (CT) in diabetic patients with and without diabetic retinopathy (DR) against healthy controls.
• To investigate the association between diabetic retinopathy and changes in choroidal thickness.

Main Methods:

• A prospective observational study involving 132 participants.
• Choroidal thickness (CT) measured at five points using spectral domain optical coherence tomography (SD-OCT).
• Analysis included OCT measurements, insulin use, lipid profiles, age, gender, fundus examination, and glycaemic control.

Main Results:

• Choroidal thickness (CT) showed a trend toward lower values in diabetic patients with DR compared to those without.
• A statistically significant decrease in CT was observed at 1000 μm temporal to the fovea in DR patients (p=0.05).
• No significant differences in sub-foveal choroidal thickness (SFCT) were found between diabetic subgroups or in relation to DME.

Conclusions:

• Diabetic retinopathy patients exhibited a significant decrease in CT at the 1000 μm temporal subregion compared to diabetic patients without DR.
• These findings suggest that diabetes induces pathological changes in the choroid, contributing to retinopathy.
• Atrophy and dropout of the choriocapillaris may explain the observed decrease in CT in DR patients.