Role of Posterior Surface Corneal Astigmatism in Toric IOL Cases and Estimation for Best Refractive Outcome
Purpose
To evaluate the role of posterior surface corneal astigmatism contribution into total corneal astigmatism corrected by Toric IOL and compare the refractive outcomes depending on its estimation during IOL calculation.
Methods
Forty-two eyes of 35 patients underwent Toric IOL implantation with 2 years follow-up. Pentacam was used for corneal topography pre-op. Posterior surface astigmatism was measured and estimated for IOL calculation in 22 cases. AcrysofToric Calculator was used for all calculations. Control group included 20 eyes with Toric IOL calculated without posterior surface corneal astigmatism taken into consideration. The uncorrected visual acuity, best corrected visual acuity, residual refractive sphere, residual keratometric and refractive cylinders were measured.
Results
All eyes treated by implantation of AcrySof Toric IOL had significant improvement in best corrected and uncorrected visual acuity (BCVA, UCBA). Six eyes in control group had a postop residual refractive error which allowed the patients to wear glasses successfully. All eyes in 1st group had emmetropia postop. The mean refractive cylinder decreased significantly after surgery from – 2.40 ± 1.28D to -0.5 ±0.36 D. There was no significant complication during or after surgery.
Conclusion
Posterior surface corneal astigmatism should be taken into consideration during Toric IOL calculation to improve visual outcomes.