Aim : To evaluate the visual , refractive , topographic outcomes and potential complications of penetrating keratoplasty versus deep anterior lamellar keratoplasty in treatment of keratoconus cases. Patients and Methods : In this prospective interventional comparative clinical study, 40 eyes of patients with keratoconus needing keratoplasty either DALK or PKP were enrolled . The primary outcome measure after both groups was the BSCVA 12 months postoperatively .The secondary outcome measures included UCVA , mean spherical equivalent, mean manifest refractive cylinder ,mean keratometric readings, mean topographic astigmatism ,endothelial cell count and endothelial cell loss . Results : 40 eyes of 35 patients with keratoconus were enrolled : 20 eyes had undergone DALK , and 20 eyes had undergone PKP . The follow up period for both groups was 12 months. Both study groups demonstrated a comparable outcome in terms of the BSCVA: 0.545±0.095 and 0.55±0.095 (P =0.868),UCVA: 0.335±0.093 and 0.306±0.112(P = 0.379),mean manifest refractive cylinder : -3.08±0.494 and -3.35±1.339 (P = 0.394) , mean K: 45.26±1.473D and 45.07±1.755D (P = 0.713)and topographic astigmatism: 3.725±1.017 and 4.095±1.466 (P = 0.359) in DALK and PKP respectively . However, the postoperative endothelial cell density in DALK (2768.6±213.101) differs significantly from it in PKP (2375.65±192.25) (P <0.001) and the percentage of endothelial cell loss was statistically significant higher in PKP 14.206±2.278 compared to DALK 1.533±0.792 (P<0.001). Also, there was a statistically significant difference in mean spherical equivalent between both groups with myopic shift in DALK group -4.663±0.915 and-3.413±2.049 P =0.013. The endothelial graft rejection rate in PKP was 15 % while in DALK it was 0 %. Conclusion: Deep anterior lamellar keratoplasty is an effective and safe alternative surgical technique to the standard penetrating keratoplasty in treatment of keratoconus. Keywords Penetrating keratoplasty; Deep anterior lamellar keratoplasty; big bubble and Keratoconus Statistics Article View: 49 PDF Download: 36