Purchase this article with an account.
F. Rufer, S. Sander, A. Frimpong-Boateng, C. Erb; Comparison of the Thinnest Point of the Cornea and the Central Corneal Thickness in 390 Normal Subjects. Invest. Ophthalmol. Vis. Sci. 2008;49(13):1025. doi: https://doi.org/.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Knowledge on the residual corneal layer thickness is important for planning laser refractive surgery. The aim was to characterize the thinnest point of the cornea compared to the central corneal thickness in normal subjects and to investigate whether there is an influence of gender, age, refraction and intraocular pressure.
The central corneal thickness and the thinnest point of the cornea were determined with the Orbscan II in 390 Caucasian normal 10 - 80-year-old subjects (mean 41 ± 16 years). Autorefraction, visual acuity testing and Goldmann applanation tonometry were carried out. Difference between the two sides, influence of gender and measuring repetition accuracy were tested for statistical significance with t tests, the influence of age with non-parametrical test methods.
On the right side, the mean central corneal thickness was 595 ± 40 µm, the thinnest point 584 ± 40 µm. On the left side, the mean corneal thickness was 594 ± 40 µm, the thinnest point 581 ± 42 µm. The differences in both eyes were statistically significant (p < 0.001). The mean distance from the thinnest point to the corneal center was 559 µm ± 422 µm in the right eyes and 692 µm ± 450 µm in the left eyes. In the right eyes, the thinnest point was located in the inferior temporal quadrant in 59.2% of the cases, compared to 66.6% in the left eyes. No influence of gender, refraction and intraocular pressure on the thickness of the thinnest point of the cornea could be observed. The difference between central corneal thickness and thickness at the thinnest point was not subject to a statistically significant influence of age.
The thinnest point of the cornea directly neighbors the optical axis. In the calculation of the residual corneal layer thickness in laser refractive surgery, the thinnest point of the cornea should form the basis.
This PDF is available to Subscribers Only