Large (9 mm) Deep Anterior Lamellar Keratoplasty with Clearance of a 6-mm Optical Zone Optimizes Outcomes of Keratoconus Surgery.
To evaluate the outcomes of a 9-mm deep anterior lamellar keratoplasty (DALK) with removal of the deep stroma limited to the central 6-mm optical zone.



Prospective, noncomparative, interventional case series.



A total of 80 consecutive keratoconic eyes without deep stromal scarring, with at least 1 postoperative examination 1 month after complete suture removal.



A standardized DALK was performed, including (1) deep trephination of the recipient bed 450 to 550 μm in depth and 9 mm in diameter; (2) pneumatic dissection; (3) debulking of approximately 80% of the anterior stroma; (4) removal of the deep stroma (bubble roof) from a central 6-mm optical zone; and (5) transplantation of a 9-mm anterior corneal lamella cut by microkeratome-assisted dissection (400-μm head) and sutured with a double running 10-0 nylon suture.



Success rate and type of pneumatic dissection obtained; best spectacle-corrected visual acuity (BSCVA), refractive astigmatism (RA), and topographic astigmatism (TA), central corneal thickness (CCT) and endothelial cell density 12 months postoperatively; and intraoperative and postoperative complications.



Pneumatic dissection created a "big bubble" in 67 of 80 eyes (83.7%), all of them but 1 (1.5%) being of type 1 according to the classification by Dua et al. After complete suture removal, BSCVA averaged 0.09±0.72 logarithm of the minimum angle of resolution (logMAR) and was ≥20/20 in 28 eyes (35%), ≥20/25 in 54 eyes (67.5%), and ≥20/40 in 76 eyes (95%); RA averaged 3.10±1.30 diopters (D), with 73 eyes (91%) within 4.5 D and none above 6 D; regular TA was detected in 72 eyes (90%); mean CCT was 492±62.10 μm; postoperative endothelial cell density averaged 2026±397cells/mm2with a mean cell loss of 11.2%. Intraoperative complications included loss of suction (n = 1) and perforation (n = 4). No conversion to penetrating keratoplasty was necessary. After surgery, double anterior chamber was observed in 2 cases (2.5%), both managed successfully by air filling of the anterior chamber. Stromal rejection was observed in 6 eyes (7.5%) and was reversed with topical steroids in all cases.



In keratoconic eyes without deep stromal scars, the combination of a graft larger than conventional ones with limited removal of deep stroma can improve visual and refractive outcomes of DALK, while minimizing the rate of complications.
Ospedale Privato "Villa Igea," Department of Ophthalmology, Forlì, Italy; Istituto Internazionale per la Ricerca e Formazione in Oftalmologia, Forlì, Italy. Electronic address: mbusin@yahoo.com.
Massimo
M
Busin
Ospedale Privato "Villa Igea," Department of Ophthalmology, Forlì, Italy; Istituto Internazionale per la Ricerca e Formazione in Oftalmologia, Forlì, Italy; Ospedale "SS. Giovanni e Paolo," Department of Ophthalmology, Venezia, Italy.
Pia
P
Leon
Ospedale Privato "Villa Igea," Department of Ophthalmology, Forlì, Italy; Istituto Internazionale per la Ricerca e Formazione in Oftalmologia, Forlì, Italy; Rabin Medical Center, Department of Ophthalmology, Petah Tikva, Israel; Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
Yoav
Y
Nahum
Ospedale Privato "Villa Igea," Department of Ophthalmology, Forlì, Italy; Istituto Internazionale per la Ricerca e Formazione in Oftalmologia, Forlì, Italy; University of "Magna Graecia," Department of Ophthalmology, Catanzaro, Italy.
Vincenzo
V
Scorcia
D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D003315:Cornea / Q000473:pathology / Q000601:surgery*; D019781:Corneal Topography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007640:Keratoconus / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D015948:Keratoplasty, Penetrating / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012029:Refraction, Ocular / Q000502:physiology*; D013997:Time Factors; D016896:Treatment Outcome; D014792:Visual Acuity; D055815:Young Adult