Aspheric toric IOL implantation and LRI in eyes with cataracts and astigmatism
Reviewed by Jonathan Chan

This is a prospective study from a single unit to compare the visual outcome of aspheric toric intraocular lens (IOL) implantation and limbal relaxing incisions (LRI) for management of coexisting age-related cataracts and astigmatism. Sixty eyes of 60 patients with visual significant cataracts and coexisting corneal astigmatism ≤3 dioptres were randomised to undergo phacoemulsification with either aspheric toric IOL or aspheric monofocal IOL with LRI. The main outcome measures were postoperative three month uncorrected visual acuity (UCVA), contrast sensitivity, rotational stability of the toric IOL and spectacle independence. Both groups achieved significantly better than baseline measurements for postoperative UCVA, contrast sensitivity and refractive astigmatism (p≤0.001). There was no significant difference detected for these parameters between LRI and toric IOL groups postoperatively. At both postoperative month one and three, the percentages of eyes in need of spectacles were lower in the toric group than the LRI group (p≤0.030). IOL misalignment was noted in three eyes in the toric group (mean misalignment 7.67±4.04°). On the vector analysis, magnitude of error (ME) was negative in the LRI group indicating undercorrection, whereas the ME was close to zero for toric group. There were no IOL misaligned more than 10° axis of rotation. None of the eyes required any extra surgical intervention. The authors conclude that both toric IOL implantation and LRI were effective in correcting corneal astigmatism ≤3 dioptres during phacoemulsification, while LRI tended to undercorrect astigmatism. The authors also conclude that the limitations of the study related to the sample size, which was relatively small. Post hoc power analysis showed that this study had a power of 34.8% to detect a significant difference of postoperative astigmatism at three months between toric IOL and LRI. Another limitation of this study was short follow-up period.

Comparative evaluation of aspheric toric intraocular lens implantation and limbal relaxing incisions in eyes with cataracts and ≤3 dioptres of astigmatism.
Lam DKT, Chow VWS, Ye C, et al.
BRITISH JOURNAL OF OPTHALMOLOGY
2016;100:258-62.