ESCRS - PP20.01 - Refractive Cylinder Following Toric Intraocular Lens Implantation: To Flip Or Not To Flip?

Refractive Cylinder Following Toric Intraocular Lens Implantation: To Flip Or Not To Flip?

Published 2023 - 41st Congress of the ESCRS

Reference: PP20.01 | DOI: 10.82333/xg38-ve96

Authors: Khayam Naderi* 1 , Ashmal Jameel 2 , Chris Hull 3 , David O'Brart 1

1Ophthalmology ,St.Thomas' Hospital,London,United Kingdom;Ophthalmology ,King's College London,London,United Kingdom, 2Ophthalmology ,St.Thomas' Hospital,London,United Kingdom, 33. School of Health Sciences, Optometry and Visual Sciences,City University ,London,United Kingdom;Ophthalmology ,King's College London,London,United Kingdom

Toric Intraocular lens (TIOL) implantation in patients with high astigmatism can lead to superior uncorrected distance visual acuity (UDVA) and better quality of life (QOL) outcomes compared to spherical IOLs. Full correction of a patient’s cylinder with a TIOL can potentially lead to a ‘flip’ in the cylindrical axis, which may compromise quality of vision. We analysed the effects of post-operative cylinder axis ‘flip’ on vision and QOL scores in two groups of patients receiving TIOLs as part of a prospective randomised control trial. This was a post-hoc analysis of 6-month follow-up data.

University Teaching Hospital 

43 eyes of 43 patients with a corneal astigmatism of 1.50D or more was randomised to receive ‘off-the-shelf’ (OTS) TIOLs of 2.0D or 4.0D cylinder power combined with opposite clear corneal incisions where appropriate, and 41 eyes of 41 patients was randomised to receive fully tailored (FT) TIOLs. The refractive aim in each patient was to fully correct the pre-operative astigmatism, aiming for emmetropia. Flipping the cylinder was defined as a change in axis of 900 +/- 22.50 from the baseline biometric steep axis. Uncorrected distance visual acuity (UDVA), best-corrected distance visual acuity (BDVA), residual refractive cylinder (RC), and CATPROM-5 QOL scores was collected at 6 months post-operatively. 

Mean (standard deviation) UDVA was 0.16 (0.15) in OTS and 0.10 (0.13) in FT (p=0.075); mean BDVA was 0.01 (0.10) in OTS and -0.01 (0.09) in FT (p=0.34, -0.063, 0.022); mean RC was 0.89D (0.50) in OTS and 0.84D (0.42) in FT (p=0.59). There was an axis flip in 16/43 eyes in the OTS group and in 12/41 eyes in the FT group (p=0.49). There were no statistically significant differences in the CATPROM-5 scores between the ‘flipped’ (-6.26 (2.66)) and ‘unflipped’ (-6.09 (3.28)) cases in the OTS group (p=0.86), or between the ‘flipped’ (-5.71 (3.53)) and ‘unflipped’ (-4.98 (2.65)) cases in the FT group (p=0.47). There were no statistically significant differences in the UDVA, BDVA, or RC between the ‘flipped’ and ‘unflipped’ cases in either group.

Based on the findings in our cohort of patients with age-related cataract, patients appear to have a reasonable amount of tolerance to ‘flipping’ of the cylinder following TIOL implantation, with no difference in the post-operative CATPROM-5 scores at 6 months following surgery.