Abstract
Purpose: :
DSAEK grafts are usually cut by a micro-keratome or a femto-second laser after the epithelial side of the donor cornea has been applanated. This approach often results in variable central graft thickness in different grafts and an increase in graft thickness towards the periphery in every graft. The purpose of this study was to evaluate if DSAEK grafts can be prepared from the endothelial side by a femto-second laser, resulting in reproducible, thin grafts of even thickness.
Methods: :
A CZM 500 kHz Visumax femto-second laser was used. Organ cultured donor grafts were mounted in an artificial anterior chamber with the endothelial side up and out. Posterior grafts of 8 mm diameter and 130 micron thickness were prepared by femto-second laser cutting. A standard DSAEK procedure was performed in 10 patients with Fuchs’ endothelial dystrophy. Patients were followed-up regularly for one-year and evaluated by measurement of complications, visual acuity, corneal thickness (Pentacam HR), and endothelial cell density. The group of femto-second laser cut DSAEK grafts were compared with 20 patients with Fuchs’ dystrophy treated with conventional DSAEK (Moria ALK microkeratome system).
Results: :
Femto-laser cutting of grafts and surgery was uncomplicated. All grafts were attached and cleared up during the first few weeks. After one year, the average visual acuity (decimal) was 0.30 (range: 0.16 to 0.50), corneal thickness was 0.57 mm (range 0.50 to 0.63), and endothelial cell density was 1.744 per sq. mm (range: 1.100 to 2.400 cells per sq. mm). The grafts were of uniform thickness, but substantial interface haze was present in most grafts. In the 20 eyes treated with conventional microkeratome cut DSAEK grafts average visual acuity (decimal) after one year was 0.53 (range 0.2 to 0.8), corneal thickness was 0.60 (range 0.52 to 0.71), and endothelial cell density was 1.340 (range 800 to 2.200).
Conclusions: :
DSAEK grafts can be prepared from the endothelial side using a femto-second laser. All grafts were clear after one year with satisfying endothelial cell counts and normal corneal hydration. Visual acuity was lower than in patients treated with DSAEK grafts cut with a conventional microkeratome. The inferior visual outcome is possible caused by interface scatter. Femto-second laser cutting parameters needs to be optimised to enable smooth cutting of the posterior corneal stroma.
Keywords: cornea: clinical science • cornea: endothelium • transplantation