الفهرس | Only 14 pages are availabe for public view |
Abstract Deep anterior lamellar Keratoplasty (DALK) is a surgical method that completely removes pathologic corneal stroma tissue down to the Descemet’s membrane, followed by transplantation of donor cornea without endothelium over the host bed. New techniques that use viscoelastic substance and air to directly expose Descemet’s membrane have dramatically reduced surgery time, while improving the safety of performing surgery. The indications for DALK have expanded for almost all cases of corneal opacity that have a healthy endothelial cell count, with a comparable visual outcome to penetrating Keratoplasty. Endothelial graft rejection is absent after DALK. However, stromal graft rejection, although rare, does occur. The aim of this study was to evaluate the visual outcomes and complications of deep anterior lamellar keratoplasty (DALK) using the big-bubble technique in patients with keratoconus. This non comparative interventional case study series that was carried out on 47 eyes of 46 patients presented with moderate to advanced keratoconus for DALK from December 2012 up to June 2014.Average follow up 12 months. Best spectacle-corrected visual acuity (BSCVA), refractive status, and intra- and postoperative complications were evaluated. Thirty-seven procedures (78.7%) were completed with Big-bubble formation; 6 (12.8%) required manual intrastromal dissection. Intraoperative microperforations occurred in 4 cases (8.5%). Baseline mean preoperative BSCVA was 0.036±0.017and final BSCVA at one year has a mean value of 0.38 (P < 0.001). Postoperative mean spherical equivalent refractive error and refractive astigmatism were -4.9±2.6 and -3.9±1.6 D, respectively. Main complications encountered included Loosening of the stitches observed in 11 cases (23.4%), stitches vascularization in 3 cases (6.4%), double anterior chamber occurred in two cases (4.3%), Urrets-Zavalia syndrome occurred in one case (2.1%), Stromal rejection noticed in one case (2.1%), and suture abscess in one case (2.1%). In conclusion: DALK using the big-bubble technique appears to be a safe and effective procedure in patients with keratoconus. Postoperative myopic refraction is observed in most cases. DALK has a good long-term graft survival rate, and, because it is an extraocular procedure, it is safer than PK. Further improvements in DALK techniques will likely enhance its usefulness for treatment of corneal disease in patients with noncompromised endothelium. |