Choroidal Thickness in Diabetic Patients Without Diabetic Retinopathy: A Meta-analysis

To evaluate the relationship between diabetic eyes without diabetic retinopathy and healthy eyes in subfoveal choroidal thickness.

Systematic review and meta-analysis.

An independent retrospective or prospective clinical study comparing diabetic eyes without diabetic retinopathy and healthy control eyes in the subfoveal choroidal thickness was selected. This study compiled data from publications in PubMed and Web of Science between January 1, 2008, and November 15, 2019. Heterogeneity was statistically quantified by I2 statistics, and meta-analysis was performed using a random-effects model.

Seventeen related studies were identified, including a total of 4,213 eyes, which consisted of 1,197 diabetic eyes without diabetic retinopathy and 3,016 healthy eyes. Meta-analysis clearly showed that the subfoveal choroidal thickness of diabetic eyes without retinopathy was significantly thinner than that of healthy control eyes (weighted mean difference = -14.34 μm; 95% confidence interval: -24.37 to -4.32 μm; P < .005). Similar results were obtained in sub-analysis based on the adjustment of the axial length.

This study suggests that the subfoveal choroidal thickness was thin in diabetic eyes without retinopathy compared to healthy eyes. Subfoveal choroidal thickness might be an important parameter for the development of diabetic retinopathy in diabetic eyes without retinopathy.