Original article 286 The Effect of Phaco Chop Cataract Surgery on Corneal Endothelium Mostafa I. Ahmad a , Mostafa M. Bahgat b , Khaled G. Abueleinen b , Ahmed F. ElShahed c Abstract: Aim: To evaluate the effect of Phaco Chop Cataract Surgery on Corneal Endothelium. Setting: Kasr Al-Ainy, university hospital, in the period between Aug-2021 to Feb-2022. Methods: A prospective study included 30-eyes that underwent cataract surgery using Phaco- chop technique. Endothelial cell loss (ECL) was correlated to effective phaco-time in seconds (EPT), age of the patients, and their gender 3-months postoperatively using specular microscopy. Results: This study was performed on 30 patients (17-cases were males, and 13-cases were females) who underwent phacoemulsification. Their ages ranged from 55 to 80 years, with a mean of 66.5 (± 6.54) years. The mean preoperative cell density (CD) was 2236 cell/mm 2 , that decreased to 1597 cells/mm 2 , 3-months postoperatively. This drop in CD was statistically significant (p<0.001). There was a significant positive correlation (P<0.0001) between ECL and EPT. Also, there was a significant positive correlation (P<0.0001) between EPT and cataract density. However, there was no correlation (P=0.9316) between ECL and age. Also, there was no correlation between ECL and gender (P = 0.326). There was significant improvement of visual acuity in all cases (P < 0.0001). Conclusion: Phaco Chop is an effective technique for cataract surgery. However, there was a significant effect on corneal endothelium. ECL was related EPT, which in turn was related type of senile cataract. Key Words: Phaco chop , Corneal endothelium count, Cataract surgery. a Department of Ophthalmology,, Al-Agouza Hospital, Cairo, Egypt. b Department of Ophthalmology, Faculty of medicine-Cairo University, Egypt. c Department of Ophthalmology, Faculty of medicine, Helwan university, Cairo Egypt. Correspondence to: Ahmed F. Elshahed, Department of Ophthalmology Faculty of Medicine; Helwan University. Egypt. Email: dr_aelshahed@live.com Received: 25 August 2022 Accepted: 30August 2022 Print ISSN 1110-208X Online ISSN 2357-0016