Clinical evaluation of Deep Anterior Lamellar Keratoplasty (DALK)

Background:Keratoconus is a progressive, non-inflammatory corneal ectasia with central thinning. The aim of this work was to evaluate intra and post-operative complications and final visual outcome of deep anterior lamellar keratoplasty (DALK).Methods: This prospective cohort interventional study was carried out on 20 patients aged from 20 to 65 years old with superficial corneal stromal opacities based on clinical examination and AS-OCT (anterior segment optical coherence tomography), advanced keratoconus with central corneal thickness below 400 microns or the presence of scarring in the visual axis. Results: Descemet's membrane (DM) perforation was encountered in 7 eyes attempted DALK (35%). Early epithelial defect happened in 13eyes post operatively mostly due to surgical manipulation of the grafts, 2 of them (10%) continue to the 3 months post operatively. Five eyes developed DM folds, three eyes (15%) developed Urrets-Zavalia syndrome, one eye 5% developed anterior cortical cataract, four eyes (20%) had interface haze. Best corrected visual acuity (BCVA) was affected in one case and improved in all cases with 85% of eyes achieved 0.5 or more after one year postoperative. Double anterior chamber (AC) was found in five eyes (25%). two eyes were successfully managed with single air injection.one eye needed DM Endothelial Keratoplasty. The mean recipient bed thickness was 42.850±8.869 um. Average K decreased significantly postoperatively. A low myopia was encountered at 6 months postoperatively. Conclusions: DALK led to reasonable postoperative visual and refractive outcome, patient age, peripheral descemet's fold, failed pneumatic dissection has no significant impact on postoperative visual acuity. Risk of DM detachment, interface haze and double AC and hemorrhage during trephination are the main complications.