Surgical induced astigmatism and associated factors in manual small incision cataract surgeries done at the Saint Paul’s Hospital Millennium Medical College, Addis Ababa, Ethiopia

Abstract

Background: Cataract surgery is a popular ophthalmic procedure with a high success rate for restoring vision.
Its goal is to minimize astigmatism after surgery and achieve desired refractive outcomes. This study examines Surgically Induced Astigmatism (SIA) at Saint Paul’s Hospital Millennium Medical College (SPHMMC), providing valuable insights for developing practical cataract surgery guidelines.
Objective: The objective of the study was to determine the level of post-operation astigmatism and its associated factors in manual small incision cataract surgery (MSICS) at Saint Paul’s Hospital Millennium Medical College, Addis Ababa, Ethiopia.
Design: A prospective analytical study was conducted at SPHMMC, Addis Ababa, Ethiopia.
Setting: The study included all patients who underwent MSICS cataract surgery in the SPHMMC eye clinic during the study period and agreed to participate.
Methods: The hospital-based prospective study analyzed MSICS patients at SPHMMC hospital in Ethiopia for ten months (2019/2020), excluding those with previous intraocular surgery or complications. Using convenience non-probability sampling, a structured questionnaire collected data on independent variables like age, sex, and incision details. SPSS version 23 was used to analyze the data, focusing on the dependent variable, surgically induced astigmatism. Descriptive and logistic regression analyses were performed to determine the association between factors.
Results: A total of 240 subjects aged 40-85 years with a mean age of 63.1 (SD±9.89) years and pre-operative visual acuity ranging from 6/60-LP were studied. Clinically significant surgically induced astigmatism ranged from 0 to 5.62D, with a mean SIA of 1.38D (SD±0.92D) and axis of 88.12 (SD±56.74). Multivariable logistic regression showed significant associations between surgically induced astigmatism and tunnel size (P=0.000) and suture presence (P=0.005).
Conclusion: Scleral tunnel size and wound sutures are critical factors associated with significant SIA. Whenever it is necessary to put a suture at the end of the surgery, removing it at the third postoperative visit is always important.
Recommendation: It is recommended to measure tunnel size with a caliper, especially during the beginning periods of doing MSICS, and to minimize it.