Microkeratome-Assisted Lamellar Keratoplasty for the Surgical Treatment of Keratoconus
Presented in part at: American Academy of Ophthalmology Annual Meeting, November 15–18, 2003; Anaheim, California.
Received 14 October 2004; accepted 5 January 2005. published online 09 May 2005.
Purpose
To evaluate the visual and refractive results of microkeratome-assisted lamellar keratoplasty (LK) performed on keratoconus patients intolerant to spectacles and contact lenses.
A microkeratome-assisted LK procedure was performed on 50 eyes of 50 keratoconus patients. All patients were spectacle and contact lens intolerant.
Intervention
All patients included in this study underwent a standard surgical procedure involving removal of a lamella (9 mm in diameter cut with the 250-μm microkeratome head) from the recipient cornea by means of a hand-driven microkeratome and suturing of a donor lamella (0.5 mm smaller in diameter than the removed corneal lamella, cut with the 350-μm microkeratome head) obtained from a cornea mounted on an artificial anterior chamber. Each patient was examined preoperatively and at different postoperative times (1 and 6 months and 1, 2, 3, and 4 years).
Main Outcome Measures
Uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), 1-year best contact lens-corrected visual acuity (BCLCVA), refraction, and computerized analysis of corneal topography.
Results
After suture removal was completed, both UCVA and best-corrected visual acuity were significantly improved over properative values at all examination times. One year postoperatively, when follow-up was still available for all patients, UCVA was better than 20/200 in 8 of 50 (16%) patients and BSCVA was ≥20/40 in 44 of 50 (88%) patients, whereas BCLCVA was ≥20/40 in all 50 patients. Refractive astigmatism within 4 diopters was seen in 43 of 50 (86%) patients. Corneal topographic patterns were classified as regularly astigmatic in 39 of 50 (78%) patients. The 1-year values did not change substantially at later postoperative examination times. Complications included preparation of donor grafts of poor quality that needed to be discarded (8 cases [16%]), irregular astigmatism of various degrees (11 cases [22%]), high-degree astigmatism requiring secondary intervention (6 cases [12%]), epithelial interface ingrowth (1 case [2%]), and cataract formation (1 case [2%]).
Conclusions
Microkeratome-assisted LK can be performed on corneas with moderate to advanced keratoconus with a minimal corneal thickness of >380 μm. The procedure is relatively simple, may be standardized in most of its parts, and does not involve time-consuming maneuvers. All complications recorded did not threaten vision and were dealt with successfully. Our results indicate that microkeratome-assisted LK is as efficacious as conventional penetrating keratoplasty for the surgical treatment of keratoconus. However, the time necessary to achieve stable results is considerably shorter.
1Department of Ophthalmology, Villa Serena Hospital, Forlì, Italy.
2University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania.
Correspondence and reprint requests to Prof Massimo Busin, Via Sisa 33, 47100 Forlì, Italy.
Manuscript no. 2004-186.
None of the authors has any financial interest to disclose.
ABSTRACT