Evaluation of the corneal endothelium in patients with diabetes mellitus type I and II.

BACKGROUND: The aim of the present study is to determine corneal physiology and endothelial morphology after proper image analysis technique in type I and II diabetic patients. The HbA1c level and the grade of retinopathy were also recorded and correlated with the endothelial parameters. METHODS: 41 eyes of 21 patients with type I and 59 eyes of 30 patients with type II diabetes mellitus (mean age was 40.97 ± 15.46 and 64.36 ± 10.47 years) were examined and compared to age-matched controls. Endothelial cell density (ECD), mean cell area, coefficient of variation of cell area, central corneal thickness, intraocular pressure, and grade of retinopathy were recorded. RESULTS: There was a statistically significant decreased endothelial cell density in type I disease (2428 ± 219 cell/mm2) in comparison with healthy subjects (2495 ± 191 cell/mm2, P=0.02). The diabetic corneas were thicker than normal (P=0.001). The HbA1c level was inversely correlated with the ECD (r=-0.60; P<0.0001) and correlated with the mean endothelial cell area (r=0.60, P<0.0001). Significant correlation was observed between the endothelial morphology and grade of diabetic retinopathy (r=-0.40, ECD; r=0.38, mean cell area; P=0.01 for both). In type II diabetes mellitus no significant difference was found in the evaluated values. CONCLUSIONS: The present study disclosed the alteration of the corneal endothelial morphology in type I diabetes mellitus as compared to normal subjects. The results indicated that type I diabetic corneas are more susceptible to environmental changes than type II corneas.

Comparison of central corneal thickness measurements with a new optical device and a standard ultrasonic pachymeter.

PURPOSE: To compare central corneal thickness (CCT) values obtained with ultrasonic pachymetry and a new optical method using partial coherence interferometry (PCI). SETTING: Department of Ophthalmology, Medical Health and Science Center, University of Debrecen, Debrecen, Hungary. METHODS: The study comprised 136 eyes of 70 patients whose spherical refractive error was not greater than +/-6.0 diopters (D) and whose keratometric astigmatism was not greater than 2.0 D. Central corneal thickness was measured 5 times with a new optical device (ACMaster, Zeiss) and with an ultrasonic pachymeter (AL-2000, Tomey). All measurements were obtained by the same investigator. RESULTS: Mean CCT was 531.2 microm +/- 3.9 (SD) with PCI and 547.8 +/- 36.0 microm with the ultrasonic device. The difference between groups was significant (P = .001). There was no difference between CCT values measured in right and left eyes (P = .55) with ultrasonography and PCI (P = .67). The coefficient variation was 0.73% for PCI and 6.5% for ultrasonography. Correlation between the CCT measurements with both devices was strong and statistically significant (Spearman correlation = .91, P = .001). CONCLUSIONS: Mean CCT values measured by the PCI method were significantly smaller than those measured by the ultrasonic device. Central corneal thickness measured with PCI is more reproducible and seems to be more reliable than that measured by ultrasonography.