Posters

Correction of low corneal astigmatism (1.00-2.00D) during cataract surgery: toric intraocular lenses vs limbar relaxing incisions (LRI) - six months of follow-up comparative study

Poster Details

First Author: P.Leon ITALY

Co Author(s):    M. Pastore   A. Zanei   I. Umari   D. Tognetto     

Abstract Details

Purpose:

The aim of this study was to evaluate and compare asferical toric intraocular lens (IOL) implantation and asferical monofocal IOL implantation with limbar relaxing incisions (LRI) to manage low corneal astigmatism (<2.0D) during cataract surgery. The study compared the effectiveness, predictability and safety of both techniques. Outcomes included visual and refractive results, with specific attention to the need for spectacles and optical aberration results.

Setting:

University Eye Clinic of Trieste

Methods:

Prospective randomized comparative clinical study included patients having cataract and preoperative corneal astigmatism between 1.0 and 2.0D. 51 eyes (48 patients) with cataract associated to corneal astigmatism were randomized divided in two groups. Group A had Toric IOL implantation (AcrySof® IQ Toric IOL, Alcon Inc.) and Group B received monofocal IOL implantation (AcrySof® IQ Aspheric IOL, Alcon Inc.) with peripheral corneal relaxing incisions. The size and location of LRI was performed according to the Nichamin's normogram and based on the procedure described by Langerman. Toric IOL cylinder power and axis placement were determinate using the IOL manufacture's online calculator (Acrysof toric IOL Calculator). In all surgeries, phacoemulsification (Infiniti® Vision System Ozil, Alcon, Inc) was performed through a 2.2mm corneal incision and was followed by the implantation of foldable IOL in the posterior capsular bag with a Monarch II injector (Alcon, Inc). Outcomes considered were: visual acuity, postoperative residual astigmatism, endothelial cell count, spectacle need and patients satisfaction. To determine postoperative toric axis all patients who underwent the toric IOL implantation were further evaluated with the OPD Scan III (Nidek Co, Japan). For a misalignment more than 10 degrees of rotation repositioning of IOL was required. Follow-up lasted at 6 months.

Results:

The mean uncorrected distance visual acuity (UDVA) and the best corrected visual acuity (BCVA) demonstrated statistically significant improvement after surgery in both groups. At the end of the follow-up the UCVA was statistically higher in the toric IOLs implanted patients compared to the patient how underwent implantation of monofocal IOL plus LRI. Refractive spherical and cylindrical correction decreased significantly in both groups and the mean mean residual refractive astigmatism was of 0.5D for toric group and 1.1D for LRI gruop (p<0.01). No difference was observed in postoperative endothelial cell count between the two groups (p < 0.01).

Conclusions:

The two surgical procedures demonstrated a significant decreased of astigmatism. Despite the documented efficacy for both surgery techniques in the aim to reduce the pre-operatory astigmatism, the toric IOL implantation has been more effective e predictable compared to limbar relaxing incision. Toric IOL implantation was more effective and predictable than incision surgery, resulting in greater spectacle independence. FINANCIAL INTEREST: NONE