Abstract
Purpose: :
Performing the central 3 mm corneal punch prior to punching the outer corneal tissue has been proposed as a method to improve centration of the optic in the Boston Type I Keratoprosthesis. To our knowledge, no quantitative analysis has been performed to evaluate this method.
Methods: :
In 7 patients who underwent implantation of the Boston Type I Keratoprosthesis, the central opening for the optical core was punched before punching the larger outer donor tissue. The distance from the margin of the corneal donor to the central optic was measured on slit lamp photography using computerized software (PixelStick Ver 2.3, Pixelated Software).
Results: :
The average diameter of the cornea carrier tissue was 8.54 mm (SD = 0.21) vertically and 8.68 mm (SD = 0.30) horizontally. The average deviation from perfect centration of the optic was 0.08 mm (SD = 0.08) vertically and 0.10 mm (SD = 0.04) horizontally. This represented an average error of 0.98% and 1.10% respectively.
Conclusions: :
Punching the 3 mm central optic prior to the outer corneal tissue is a reliable method for centering the optic in the Boston Keratoprosthesis. This may yield improvements in optic quality and ease of suturing of the device.
Keywords: keratoprostheses • transplantation • cornea: clinical science