98th Annual Meeting DOG 2000

K 827

Central corneal thickness under therapy with topical Latanoprost and Dorzolamide

R. Stodtmeister, M. Kron

Introduction: According to.animal experimental results the pressure lowering effect of Latanoprost eye drops may be caused by a reduction of the collagen part within the uveoscleral outflow pathway. We maintained the hypothesis that topically applied Latanoprost reduces the collagen of the cornea and thus leads to a thinning of the cornea, which could be assessed by ultrasound pachometry. We checked this hypothesis in a retrospective study in glaucoma patients treated with topical Latanoprost and for a comparison with topical Dorzolamide. We had already measured the corneal thickness for the correction of the Goldmann applanation tonometry readings, since central corneal thickness may influence these readings to a clinical relevant degree.

Patients and methods: Latanoprost group: 21 males, 21 females. Age: (minimum-median-maximum) 50-67-89 years; follow-up time: 5-21-26 months. Dorzolamide group: 21 males, 21 females. Age: 44-69-87 years; follow-up time: 7-20-27 months. Ultrasound pachometry unit used: Pachette (DGH Technology/Technomed); location of measurement: 1,5 mm lateral of the fixation light reflex. Statistical evaluation was made by multiple linear regression.

Results: Latanoprost group: Decrease of corneal thickness in females by -1.0 µm/month (p=0.001) and in males by -0.57 µm/month (p=0.055). Dorzolamide group: Increase of corneal thickness in females by 0.16 µm/month (p=0.547) and in males by 0.51 µm/month (p=0.061).

Discussion: By comparison of two treatment groups methodological influences should be excluded as far as possible. These data show that during Latanoprost treatment corneal thickness decreases, which according to animal experimental obsevations may be caused by a reduction of collagen. The difference in the decrease of corneal thickness between males and females is interesting. From this fact it may be concluded that the pressure lowering effect should be more pronounced in females than in males. The increase of corneal thickness during Dorzolamide treatment in males was not observed in previous studies.

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