Deep anterior lamellar keratoplasty versus penetrating keratoplasty for keratoconus: a clinical trial.
OBJECTIVE
To compare deep anterior lamellar keratoplasty (DALK) using the big-bubble technique to penetrating keratoplasty (PK) in patients with keratoconus.


METHODS
In this clinical trial, patients with moderate to advanced keratoconus with poor spectacle-corrected visual acuity and intolerant to contact lens wear were enrolled. DALK was performed using the big-bubble technique, and a full-thickness donor cornea without Descemet membrane was sutured to the recipient bed. PK was performed conventionally with a Hessburg-Barron suction trephine. Three types of suturing were used for both groups. Postoperative refractive errors, best-corrected visual acuity (BCVA), contrast sensitivity function (CSF), and higher order aberrations (HOAs) were compared between the study groups.


RESULTS
The study included 81 eyes of 81 patients. Forty-six eyes underwent DALK from which 4 were excluded because of failure to achieve bared Descemet membrane. Thirty-five eyes received PK. Mean patient age was 26.91 ± 7.9 versus 30.89 ± 10.3 years in the DALK and PK groups, respectively (P = 0.06). Mean follow-up period was 22.0 ± 7.9 months in the DALK group and 24.6 ± 3.5 months in the PK group (P = 0.32). Mean postoperative spherical equivalent refractive error was -3.23 ± 3.4 diopters in the DALK group versus -2.22 ± 4.6 diopters in the PK group (P = 0.28), and mean postoperative BCVA was 0.18 ± 0.08 and 0.15 ± 0.10 logarithm of the minimum angle of resolution, respectively (P = 0.12). CSF and total aberrations and HOAs were comparable in the study groups.


CONCLUSIONS
DALK is an effective alternative surgical procedure for patients with keratoconus; the outcomes are comparable to PK in terms of refractive errors, BCVA, CSF, and HOAs.
Javadi
Mohammad Ali
MA
Ophthalmic Research Center and Department of Ophthalmology, Labbafinejad Medical Center, Shahid Beheshti University, Boostan 9 St., Pasdaran Avenue, Tehran, Iran. ma_javadi@yahoo.com
Feizi
Sepehr
S
Yazdani
Shahin
S
Mirbabaee
Firooz
F
D057128:Aberrometry; D000293:Adolescent; D000328:Adult; D015350:Contrast Sensitivity / Q000502:physiology; D016039:Corneal Transplantation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007640:Keratoconus / Q000601:surgery*; D015948:Keratoplasty, Penetrating; D008297:Male; D008875:Middle Aged; D012029:Refraction, Ocular / Q000502:physiology; D012030:Refractive Errors / Q000503:physiopathology; D013536:Suture Techniques; D016896:Treatment Outcome; D014792:Visual Acuity / Q000502:physiology; D055815:Young Adult