DALK effective for numerous corneal pathologies, longitudinal study finds

Deep anterior lamellar keratoplasty, performed as described by Gerrit Melles, MD, can be used to effectively manage a variety of corneal lesions, a longitudinal study found. However, graft rejection remains a significant complication, although surgeons reversed all cases experienced in the study, the authors said.

Bruce A. Noble, FRCS, FRCOphth, of Yorkshire Eye Hospital, England, and colleagues reviewed the visual outcomes and complications of deep anterior lamellar keratoplasty (DALK) performed in 80 eyes of 68 consecutive patients who averaged 34.2 years of age. Their results are published in the January issue of Cornea.

Most cases — 58 eyes — had keratoconus, while six eyes had herpes simplex keratitis, five had corneal stromal dystrophy, two had stem cell failure with scarring, one had a corneal dermoid and one eye had corneal opacity, according to the study.

Surgeons used the Melles technique in all cases. The researchers found that patients' mean central corneal thickness increased from 0.42 mm at baseline to 0.62 mm postop. At 21.2 months mean follow-up, 24.7% of patients had best corrected visual acuity of 6/6, and BCVA was 6/9 or better in 69.9% of patients and 6/12 or better in 84.9%, according to the study authors.

Postoperatively, refractive cylinder averaged 3.31 D and spherical equivalent averaged –2.54 D. Overall, 52.2% of eyes had a refractive cylinder less than ±3 D and 49.3% had a spherical equivalent less than ±3 D, the authors said.

In 11 eyes, surgeons encountered Descemet's membrane perforations and chose to extract and replace the full-thickness corneal button in seven of these cases.

The researchers excluded these eyes from the data analysis, the authors noted.

Graft rejection episodes were experienced in 9.6% of eyes, but surgeons successfully reversed the rejection in all cases. Only one eye with severe stem cell deficiency experienced graft failure, they said.

"Our results confirm the usefulness and safety of this procedure in conditions with no endothelial involvement. Graft rejection remains a significant complication but is associated with good recovery because the endothelium is spared," the authors said.