Comparing postoperative astigmatism following toric IOL implantation VS femtosecond laser-assisted astigmatic keratotomy

Meta-analysis of nine studies revealed that toric IOLs could result in less postoperative astigmatism, though they could be contraindicated in some cases. Image credit: ©忆江 – stock.adobe.com

Taiwanese investigators compared femtosecond laser-assisted astigmatic keratotomy (FSAK) to toric intraocular lens (IOL) implantation to treat astigmatism in patients undergoing cataract surgery. The research found that both interventions were effective to that end. However, the toric IOLs offered a slight edge in that they caused less postoperative astigmatism and were associated with better postoperative uncorrected distance visual acuity (UDVA),¹ according to first author Wei-Ting Yen, MD from the Department of Ophthalmology, Tri-Service General Hospital and the National Defense Medical Center, both in Taipei City, Taiwan.

Yen and colleagues conducted a literature search that compared the two procedures. The primary outcomes were the postoperative refractive cylinder, correction index, UDVA, the proportion of patients with a residual refractive cylinder of 1.00 diopter (D) or less and the target-induced (TIA) and surgically induced astigmatism (SIA). To date, studies have compared the two procedures to correct astigmatism, but no consensus has been reached regarding which is associated with superior outcomes.

The investigators explained the rationale for the study of these popular refractive options. “While toric IOLs offer numerous benefits for astigmatism correction, there are cases in which the risk of IOL rotation could make other options more suitable. In situations in which a patient is at a higher risk of IOL rotation, such as in cases with post-traumatic eyes or eyes with long axial lengths, addressing astigmatism on the corneal surface through other methods can be an alternative choice,²” they wrote.

Arcuate keratotomy³ is performed to correct astigmatism by making precise incisions in the cornea, and it can be performed in conjunction with femtosecond laser technology, because of the precision and predictability of the corneal incisions.⁴ The increasing popularity of FSAK is influenced by the growing prevalence of femtosecond laser-assisted cataract surgery,⁴ the authors explained.

Similar meta-analyses in the past have reported that toric IOLs provide better visual acuity and less residual astigmatism compared with corneal relaxing incisions.^5,6 A recently meta-analysis also found that toric IOLs have less residual postoperative astigmatism, but there is no significant difference in the UDVA.⁷ Recently, numerous studies have provided updated information on postoperative residual astigmatism and visual outcomes between toric IOLs and FSAK after cataract surgery.^8-17 Based on the previous studies, the study under discussion focused on data to December 2023 to compare the two procedures.

Literature review

The authors identified nine studies that reported on a total of 590 patients. “The meta-analysis revealed that toric IOLs could result in less postoperative refractive cylinder and provide better UDVA compared with FSAK. The trial sequential analysis disclosed strong evidence of lower postoperative refractive cylinder in the toric IOL group compared with that of the FSAK group. FSAK showed a smaller correction index and lower mean TIA and SIA compared with toric IOLs,” Dr Yen and colleagues reported.

Based on the literature review, they concluded, “For cataract patients, both FSAK and toric IOLs are effective methods for correcting astigmatism. However, toric IOLs offer less postoperative astigmatism and result in better postoperative UDVA compared with FSAK. The vector analysis of astigmatism showed that toric IOLs can also produce higher TIA and SIA. In addition, neither method was associated with severe untreatable complications. Therefore, the conclusion is that toric IOLs are the preferred choice for astigmatism correction in cataract patients and FSAK serves as a viable alternative when toric IOLs are contraindicated.”

References

1. Yen W-T, Weng T-H, Lin T-Y, Tai M-C, Chen Y-H.Femtosecond laser-assisted astigmatic keratotomy versus toric IOL implantation for correcting astigmatism in cataract patients: a systematic review and meta-analysis with trial sequential analysis. Br J Ophthalmol. 2025;109:324–332. doi:10.1136/bjo-2024-325195

2. Rubenstein JB, Raciti M. Approaches to corneal astigmatism in cataract surgery. Curr Opin Ophthalmol. 2013;24:30. doi:10.1097/ICU.0b013e32835ac853

3. Titiyal JS, Baidya KP, Sinha R, et al. Intraoperative arcuate transverse keratotomy with phacoemulsification. J Refract Surg. 2002;18:725–30. doi:10.3928/1081-597X-20021101-10

4. Vickers LA, Gupta PK. Femtosecond laser-assisted keratotomy. Curr Opin Ophthalmol. 2016;27:277–284. doi:10.1097/ICU.0000000000000267

5. Kessel L, Andresen J, Tendal B, et al. Toric intraocular lenses in the correction of astigmatism during cataract surgery: a systematic review and meta-analysis. Ophthalmology. 2016;123:275-286.doi:10.1016/j.ophtha.2015.10.002

6. Lake JC, Victor G, Clare G, et al. Toric intraocular lens versus limbal relaxing incisions for corneal astigmatism after phacoemulsification. Cochrane Database Syst Rev. 2019;12:CD012801. doi:10.1002/14651858.CD012801.pub2

7. Zheng J, He L, Zhong J. Effect of femtosecond laser-assisted arcuate keratotomy versus toric intraocular lens implantation on correction of astigmatism in cataract surgery: a systematic review and meta-analysis.Lasers Med Sci. 2023;38:225. doi:10.1007/s10103-023-03893-0

8. Titiyal JS, Khatik M, Sharma N, et al. Toric intraocular lens implantation versus astigmatic keratotomy to correct astigmatism during phacoemulsification.J Cataract Refract Surg. 2014;40:741–747. doi:10.1016/j.jcrs.2013.10.036

9. Yoo A, Yun S, Kim JY, et al. Femtosecond laser-assisted arcuate keratotomy versus toric IOL implantation for correcting astigmatism.J Refract Surg. 2015;31:574–578.doi:10.3928/1081597X-20150820-01

10. Shaarawy AS, Elmassry AA, Elhenawy HM. Toric intraocular lens implantation in comparison to femtoassisted astigmatic keratotomy to correct astigmatism during phacoemulsification cataract surgeries.Egypt J Cataract Refract Surg. 2020;26:16–25. doi:10.21608/ejcrs.2020.193256

11. Hernandez R, Almenara C, Soriano D, et al. Toric intraocular lens implantation vs femtosecond laser-assisted arcuate keratotomy for correction of moderate astigmatism in cataract surgery. J Cataract Refract Surg. 2022;48:887–893. doi:10.1097/j.jcrs.0000000000000879

12. Kwon HJ, Lee H, Lee JA, et al. Astigmatic correction of simultaneous femtosecond laser-assisted cataract surgery (FLACS) with intrastromal arcuate keratotomy (ISAK) versus toric intraocular lens implantation with conventional phacoemulsification. BMC Ophthalmol. 2021;21:298.doi:10.1186/s12886-021-02059-2

13. Noh H, Yoo Y-S, Shin KY, et al. Comparison of penetrating femtosecond laser-assisted astigmatic keratotomy and toric intraocular lens implantation for correction of astigmatism in cataract surgery. Sci Rep. 2021;11:7340. doi:10.1038/s41598-021-86763-5

14. Lin M-Y, Shen Y-D, Tan H-Y, et al. Refractive outcomes of femtosecond laser-assisted cataract surgery with arcuate keratotomy and standard phacoemulsification with toric intraocular lens implantation. Int Ophthalmol. 2022;42:2633–2642. doi:10.1007/s10792-021-02090-8

15. Wang KY, Chen LL. Comparison of long-term efficacy of femtosecond laser arcuate keratotomy and toric intraocular lens implantation in the correction of cataract combined with low degree astigmatism. Chinese Journal of Ocular Trauma and Occupational Eye Disease. 2022;44:889–894. doi:10.1038/s41598-021-86763-5

16. Shen J, Hua Z, Zhang L, et al. n.d. Comparison of astigmatism correction and visual outcomes in mix-and-match implantations of trifocal intraocular lenses with femtosecond laser-assisted arcuate keratotomy and contralateral bifocal toric intraocular lenses.Front Med. 2023;10.doi:10.3389/fmed.2023.1237319

17. Yuan SM, Tang YR, Peng YL, et al. Effects of three methods for correction of low-degree against-the-rule corneal astigmatism during cataract surgery. Chinese J Ophthalmol. 2023;59:110–117.doi:10.3760/cma.j.cn112142-20220401-0015