Fifty-six patients participated in the study. The LTP group consisted of 28 patients (6men) with a mean age±SD of 58.79±1.65 years (range, 42-75 years). The control group consisted of 28 patients (9men) with a mean age±SD of 59.79±1.35 years (range, 41-80years). There were no significant differences in age, gender or eye.