PURPOSE: To compare the anterior segment parameters including precorneal tear film thickness (PTFT) using Pentacam(R) (Oculus, Wetzlar, Germany) between normal control and dry eye groups and to examine the relationships between the PTFT and other parameters for dry eye. METHODS: The present study included 23 normal controls (31 eyes) and 25 patients with dry eyes (31 eyes). We compared measurements including PTFT, corneal thickness and astigmatism using Pentacam(R) and analyzed the correlations among the PTFT and fluorescein tear break-up time (FBUT), Schirmer I test (without anesthesia), and ocular surface disease index (OSDI). RESULTS: The mean PTFT in dry eyes (21.1 +/- 2.0 microm) was significantly thinner than in normal eyes (37.6 +/- 2.0 microm; p < 0.01). In the dry eye group, the corneal thickness was thicker than in the normal eye group but there were no clinically significant differences. The dry eye group experienced more frequent and severe corneal astigmatism compared with the normal group. OSDI scores showed a weak negative correlation with objective clinical measures of dry eye (FBUT, Schirmer I test) but was not statistically significant. However, OSDI was statistically significantly negatively correlated with PTFT (r = -0.46, p < 0.01). The PTFT showed a weak positive correlation with FBUT and Schirmer I test without statistical significance. CONCLUSIONS: The mean PTFT using Pentacam(R) in the dry eye group was thinner than in the normal group. Additionally, the PTFT was correlated with subjective symptoms. Therefore, the PTFT measurement using Pentacam(R) could be considered a useful method for diagnosis and treatment of dry eye.
Astigmatism ; Diagnosis ; Fluorescein ; Humans ; Tears*

PURPOSE: In this study, we examined the changes in corneal biomechanical parameters in patients with diabetes mellitus (DM). METHODS: Fifty patients with DM were divided into 2 subgroups, 25 diabetic patients with glycated hemoglobin (HbA1c < or = 7% and 25 diabetic patients with HbA1c > 7%) and compared with the eyes of 80 healthy subjects. Corneal biomechanical parameters were measured using ocular response analyzer (ORA). Differences in corneal biomechanical properties between healthy subjects and diabetic patients were compared. Additionally, differences in corneal biomechanical properties between diabetic patients with HbA1c < or = 7% and diabetic patients with HbA1c > 7% were compared. RESULTS: Corneal hysteresis, corneal resistance factor and central corneal thickness (CCT) were statistically significantly higher in patients with diabetes compared to healthy subjects. Goldmann tonometer, non-contact tonometer and Goldmann-correlated intraocular pressure (IOPg) were statistically significantly higher in patients with DM compared to healthy subjects, but corneal compensated IOP (IOPcc) was not statistically significantly different between healthy subjects and diabetic patients. However, corneal biomechanical parameters, which were statistically significantly different between healthy subjects and DM patients, were not statistically significantly different between diabetic patients with HbA1c < or = 7% and diabetic patients with HbA1c > 7%. CONCLUSIONS: Considering that corneal properties are different between diabetic patients and healthy subject, IOPcc measured with ORA is considered clinically useful for measuring IOP as it reflects CCT and biomechanical properties that should be revised. In diabetes, changes in corneal biomechanical properties depend on long-term glucose control rather than short-term glucose control.
Diabetes Mellitus* ; Glucose ; Hemoglobin A, Glycosylated ; Humans ; Intraocular Pressure