ESCRS - PP03.14 - Avoiding A Mixed Astigmatism Phenotype With Non-Toric Monofocal Intraocular Lenses In Eyes With Corneal Astigmatism: An Ambispective Comparative Study

Avoiding A Mixed Astigmatism Phenotype With Non-Toric Monofocal Intraocular Lenses In Eyes With Corneal Astigmatism: An Ambispective Comparative Study

Published 2026 - 44th Congress of the ESCRS

Reference: PP03.14 | Type: Free paper | DOI: 10.82333/zgjt-yw97

Authors: Dr Raksheeth Nathan Rajagopal* 1 , Dr Bhoomika Nisar 2 , Dr Shreyas Ramamurthy 1 , Dr Ramamurthy Dandapani 3

1Cornea, Cataract & Refractive Services,The Eye Foundation ,Coimbatore,India, 2Comprehensive Ophthalmology,The Eye Foundation ,Coimbatore,India, 3Cataract & Refractive Services,The Eye Foundation ,Coimbatore,India

Purpose

To evaluate whether selecting a higher-power non-toric monofocal intraocular lens (IOL) to target a myopic spherical equivalent (SE) reduces postoperative mixed astigmatism in eyes with corneal astigmatism undergoing phacoemulsification.

Setting

This mixed retrospective-prospective (ambispective) comparative cohort study was conducted in a tertiary eye care centre in southern India.

Methods

Consecutive eyes with keratometric corneal astigmatism implanted with a non-toric monofocal IOL were analyzed. In the correction-factor group (n=70), IOL power was selected to target a postoperative SE approximately equal to half the magnitude of the preoperative corneal cylinder (i.e. a myopic SE) rather than emmetropic SE. The comparator group targeted emmetropic SE (n=50). Postoperative outcomes were assessed at 2 weeks using manifest refraction, logMAR uncorrected distance visual acuity (UDVA), and corrected distance visual acuity (CDVA). Refractions were classified into postoperative refractive phenotypes based on the signs of the 2 principal meridians (emmetropia, myopic astigmatism, or mixed astigmatism)

Results

The correction-factor group implanted a median IOL power 1 diopter (0.50-1.50) higher than the emmetropic biometry suggestion. Mixed astigmatism occurred in 6/70 eyes (8.6%) versus 26/50 eyes (52.0%) (P<0.001). Myopic astigmatism occurred in 61/70 (87.1%) versus 14/50 (28.0%).
Median postoperative UDVA was 0.30 (IQR 0.17–0.47) logMAR in the correction-factor group versus 0.17 (0.17–0.39) logMAR in the no-correction group (P=0.178). Median postoperative CDVA was 0.00 (0.00–0.10) logMAR versus 0.10 (0.00–0.10) logMAR (P=0.080).
Median postoperative manifest SE was −0.56 D (IQR −0.84 to −0.41) in the correction-factor group versus 0 D (−0.38 to +0.13) in the no-correction group (P<0.001)

Conclusions

Selecting a slightly higher-power non-toric monofocal IOL to target a myopic SE substantially reduced postoperative mixed astigmatism without reducing mean CDVA. This strategy may be useful when toric IOLs are not feasible, particularly in eyes with higher corneal astigmatism.