Study of comparison of surgically induced astigmatism after small incision cataract surgery and phacoemulsification surgery

Abstract

To compare surgically induced astigmatism after manual small incision cataract surgery and phacoemulsification surgery. 2) To know the prevalence of pre-existing astigmatism, it’s magnitude and type and patients with cataract. 3) To calculate the average astigmatism induced after manual small incision cataract surgery and also to know the type of astigmatism and change in it in first month of surgery. 4) To calculate the average astigmatism induced after phacoemulsification surgery and also to know the type of astigmatism and change in its first month of surgery. 5) To study changes in astigmatism and its effect on vision after cataract surgery. 6) To compare astigmatism induced by straight and frown incision after operation.The study was carried out in Department of Ophthalmology, P.D.U government Medical College, Rajkot under guidance of operating surgeons and patients operated in the duration of 24 months from September 2020 to October 2022.Informed consent was obtained from all the patients undergoing study. It was a prospective study and all the patients were randomly selected over the above mentioned period that had cataract with normal anterior and posterior segments. To have a more homogeneous study population all the patients underwent a similar Preoperative, Intra operative, Postoperative Surgical protocols. All eyes were operated under peribulbar anaesthesia with 2% lignocaine+bupivacain+hyalronidase. Superior sclero corneal pocket tunnel with external incision of frown configuration in manual SICS and straight incision in phacoemulsification was made. All the cases with 3.2 mm of incision in phacoemulsification and 6.5 mm incision in manual SICS were taken. Surgically induced astigmatism was then calculated by the subtraction method and vector analysis.Average SIA in SICS was 1.32 SD and in Phacoemulsification was 0.60 SD which means that larger incision size increases SIA. SIA was maximum on first post-operative day and it regressed with time as noted on first post-operative month in both the groups. It decreased from 1.66 D on first postoperative day to 1.32 D on first postoperative month in SICS Patients and from 0.63 D to 0.60 D in Phacoemulsification patient.