Prevalence of pre-operative astigmatism using swept-source optical coherence tomography in patient undergoing cataract surgery

Abstract

Purpose: The purpose of this study was to assess the prevalence of pre-operative astigmatism in patient reporting for cataract surgery using swept-source optical coherence tomography (OCT) in a tertiary care eye hospital. Methods: Prospective cross-sectional study in patients undergoing cataract surgery with having age ≥35 years. Ophthalmic biometry was done using swept-source OCT (intraocular lens, IOL Master 700). The various parameters that were studied are axial length, anterior chamber depth, lens thickness, white-to-white measurement, and keratometry (K) (K1-flat K and K2-steep K). Corneal astigmatism was determined by the difference between K2 and K1 reading. Results: A total of 310 eyes from 155 patients were evaluated. There were 70 males (45.16%) and 85 females (54.83%). The mean age of study population was 64.43 ± 9.18 years. The mean corneal astigmatism was 0.91D ± 0.67D ranging from 0 to 4.21D. No astigmatism was present in 3 eyes (0.96%), astigmatism with-the-rule was detected in 90 eyes (29.03%), against the rule astigmatism was detected in 167 eyes (53.87%), and oblique astigmatism was found in 50 eyes (16.12%). 214 eyes (69.02%) had corneal astigmatism <1.00D and 96 eyes (30.98%) had corneal astigmatism ≥1.00D. Conclusion: The study shows that 30.98% of eyes reporting for cataract surgery had pre-existing corneal astigmatism ≥1.0D and were offered the option of astigmatism correction with toric IOL implantation. The larger majority of eyes 69.02% had corneal astigmatism <1.0D and could be managed with spherical monofocal IOL.