Comparison of Refractive Stability After Nontoric IOL With Limbal Relaxing Incisions Toric Iris-Claw Phakic IOL
Purpose
To compare refractive state changes in eyes implanted with non-toric and limbal relaxing incisions (LRI) versus toric iris claw phakic IOLs.
Methods
535 eyes with with-the-rule astigmatism up to 3.0 D underwent iris claw phakic IOL implantation with either non-toric IOLs and LRIs or toric IOLs. The spherical value, cylindrical value, spherical equivalent (SE) of refractive error, polar conversion of net astigmatism and visual acuity were measured preoperatively, 1, and 4 months after surgery. Main outcome measures were the pattern of changes of spherical, cylindrical, net astigmatism converted to polar values and SE values between different IOL types.
Results
263 and 272 eyes were implanted with toric and non-toric IOLs, respectively. There were no differences in spherocylinder refraction between the 2 groups prior to surgery. The mean pre-operative cylindrical error changed from -2.62 ± 0.26(D) and -2.57 ± 0.28(D) to -0.63 ± 0.38(D) and -0.94 ± 0.43(D) (p<0.05), in the toric and LRI groups, respectively. Mean pre-operative net astigmatism changed in the toric group from KP(90)0.14 ± 1.88 to KP(90) 0.03 ± 0.51 and from KP(135) -0.04 ± 1.87 to K(135) -0.08 ± 0.53. In the LRI group, net astigmatism changed from KP(90) 0.34 ± 1.90 to -0.09 ± 0.79 and KP(135) from 0.34 ± 1.72 to -0.06 ± 0.66 at post-operative 4 months. There was no significant difference in net astigmatism between the 2 groups (KP(90);p=0.292 and KP(135);p=0.818).
Conclusion
Non-toric iris claw phakic IOL implantations with LRIs are safe, efficacious and have comparable refractive and cylinder correction compared to toric iris claw phakic IOLs for cylinders of up to 3.0 Diopters at 4 months after surgery.