Modified deep lamellar keratoplasty for the treatment of advanced-stage keratoconus with steep curvature

Abstract

Purpose: To determine the clinical efficacy of modified deep lamellar keratoplasty for the treatment of advanced-stage keratoconus with steep curvature.

Design: Retrospective, noncomparative clinical trial.

Participants: Fifty-nine keratoconus patients with a curvature of more than 60 diopters (D) in 65 eyes were studied. All affected eyes were in the advanced stage with typical clinical characteristics, and 31 of the eyes had midstromal scars in the central cornea.

Methods: All patients were treated with modified deep lamellar keratoplasty. Briefly, four-fifths thickness of the corneal lamellae was cut using a Hessburg-Barron vacuum trephine (with a diameter of 7.75 mm). The incisal edge of the cornea was drawn using toothed forceps, and the lamellae were cut with a diamond knife along the stromal fibers. At the top of the cone, 2 mm (in diameter) of Descemet's membrane was left. A corneal graft (8.0 mm in diameter) was sutured to the recipient using a gradual pressure technique to decrease the occurrence of folds in the central cornea. Complications during and after the surgery were recorded. The transparency of the graft, eye vision, and cornea curvature were monitored during follow-ups.

Main outcome measures: Surgical effect and visual acuity after modified deep lamellar keratoplasty in patients with keratoconus.

Results: No corneal perforation occurred during the operations. Nine patients had mild liquid accumulation underneath the graft, but it disappeared 1 to 2 days after the surgery. The corneal graft attached to the patient's eye well, and there was no obvious fold in the center. The average best-corrected visual acuity was 20/32 between 3 months and 1 year after surgery and reached 20/25 at 1 year after the operation. There was no detectable corneal graft rejection during the follow-ups.

Conclusions: This modified deep lamellar keratoplasty procedure for the treatment of keratoconus in patients with advanced-stage disease and steep curvature seems to provide similar efficacy to penetrating keratoplasty and may decrease the risk of immune rejection when compared with historical outcomes.