Clinical outcomes after deep anterior lamellar keratoplasty using the big-bubble technique in patients with keratoconus

Am J Ophthalmol. 2007 Jan;143(1):117-124. doi: 10.1016/j.ajo.2006.09.025. Epub 2006 Oct 20.


Purpose: To report clinical outcomes of deep anterior lamellar keratoplasty (DALK) using the big-bubble technique in patients with keratoconus.

Design: Prospective noncomparative interventional study.

Setting: Single hospital.

Patients: Eighty-one unselected consecutive patients with moderate to advanced keratoconus intolerant to contact lenses and with poor spectacle-corrected visual acuity.

Intervention: DALK big-bubble technique.

Main outcome measures: Intraoperative and postoperative complications, postoperative uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), manifest refraction, corneal topography, and endothelial cell density.

Results: Seventy-eight procedures (96%) were completed as DALK. Big-bubble was achieved in 50 cases (64%); 28 (36%) required manual intrastromal dissection. Intraoperative microperforations occurred in 11 cases (13%). Baseline mean uncorrected visual acuity was 20/500 and 20/60 two years after surgery. Average preoperative BSCVA, was 20/100 and 20/30 at the end of follow-up. Final BSCVA was better in patients in whom big-bubble with exposure of the Descemet membrane was achieved (P < .05). Average keratometry and SD (standard deviation) refraction changed from 62.1 +/- 6.7 diopters and -10.76 +/- 5 diopters to 47.51 +/- 4.73 diopters and -1.81 +/- 3.2 diopters, respectively after surgery. Mean preoperative endothelial cell density was 2202.29 +/- 392.35 cells/mm(2) and 2034 +/- 438.39 cells/mm(2) two years after surgery. Two patients developed stromal rejection.

Conclusions: The DALK big-bubble technique is a valuable treatment in patients with keratoconus. Visual outcome is comparable to standard penetrating keratoplasty (PK) when formation of big-bubble with exposure of the Descemet membrane (DM) was achieved. Clinically important graft-host interface developed in some cases after manual intrastromal dissection. Stromal rejection is a rare complication.

MeSH terms

  • Adult
  • Cell Count
  • Corneal Topography
  • Corneal Transplantation / methods*
  • Endothelium, Corneal / pathology
  • Female
  • Humans
  • Intraoperative Complications
  • Keratoconus / physiopathology
  • Keratoconus / surgery*
  • Male
  • Postoperative Complications
  • Prospective Studies
  • Treatment Outcome
  • Visual Acuity / physiology