Astigmatism induced by manual small-incision cataract surgery at the Chad-China friendship university teaching hospital in N'djamena (CHU-ATC)

Introduction:The aim of our study was to evaluate the characteristics of surgically induced astigmatism following manual small-incision cataract surgery (MSICS) at the Ophthalmology Department of the Chad-China Friendship University Teaching Hospital in N'Djamena. Methodology:This was a cross-sectional, descriptive study with prospective data collection conducted from September 2024 to August 2025. Inclusion criteria comprised all patients aged 40 and over who underwent cataract surgery and were followed up until day 45. Congenital, post-traumatic, and cataracts associated with astigmatic corneal pathologies were excluded. Socio-demographic, clinical, therapeutic, and outcome variables were analysed using SPSS 18.0. Results:In total, 280 eyes from 224 patients were operated on. The mean age of patients was 60.7 +- 9.9 years, with a sex ratio of 1.3. Housewives represented 34.8% of the cohort, with the majority of patients coming from N'Djamena (86.6%). Preoperative visual acuity was <1/10 in 96.4% of cases. All patients underwent MSICS under local anaesthesia. The mean power of the emmetropising intraocular lens was 21.4 +- 3.3D. Intraoperative complications were dominated by posterior capsule rupture with vitreous loss (9.8%). Corneal oedema (9.6%) and secondary cataracts (4.5%) were the main early and late postoperative complications, respectively. Postoperative unaided distance visual acuity was >= 3/10 in 77% of cases and 82% with correction. Preoperative astigmatism for all patients was 1.3 +- 0.97D [0 to -3.50D]. The postoperative mean was 2.68 +- 1.18D [-0.50 to -6.00D], representing a mean surgically induced astigmatism of -1.38D. Conclusion:Cataract surgery by MSICS with a superior linear incision induces against-the-rule astigmatism. Keywords:astigmatism, cataract, MSICS, N'Djamena - Chad.