Analysis of corneal optic density in patients with type Ⅱ diabetes

Abstract

Abstract Purpose: To investigate the changes in corneal optic density (COD) in patients with type II diabetes and explore the possible influencing factors. Methods: Central corneal thickness (CCT) and corneal optic density (COD) were measured in 52 patients (104 eyes) with type II diabetes mellitus (DM) and 23 age-matched healthy controls (46 eyes). COD values of the anterior, middle, and posterior layers and four annulus regions (0–2, 2–6, 6–10, and 10–12 mm) were collected. Patients with DM were divided into the non-diabetic retinopathy (NDR) and diabetic retinopathy (DR) groups. Results: Patients with DM had higher COD values than the controls; the differences were significant in the total (P=0.011), anterior layer (P=0.002), middle layer (P=0.019), and 0–6 mm central region (0–2 mm, P=0.008; 2–6 mm, P=0.007). The 0–6 mm central region COD was higher in the NDR group and highest in the DR group compared with controls; the 6–12 mm peripheral COD value was highest in the NDR group. The correlation between age and COD values was lower in patients with DM than in controls. CCT was positively correlated with the total COD value (r=0.26, P=0.008) in the DM group. Conclusion: The corneal clarity of patients with DM decreased in general and altered before the appearance of DR. COD values increased in early diabetes without DR. As DR emerged, the central and peripheral COD changed differently. In addition toretinal condition, age and CCT may also affect corneal transparency of patients with DM.