Rotational Stability, Residual Astigmatism, and Ocular Aberrations of 2 Aspheric IOLs
Narrative Responses:
Purpose
To compare astigmatic correction, rotational stability and higher order aberrations after implantation of Tecnis toric intraocular lens (IOL) (Abbott Medical Optics) with Acrysof IQ toric IOL (Alcon Laboratories Inc) to correct astigmatism during cataract surgery.
Methods
Prospective randomized controlled study. Patients with senile cataract and regular corneal astigmatism from 1 to 3 diopters (D) were included. Patients were randomized into two groups: one group received Tecnis toric IOL (A) while the other group received Acrysof IQ toric IOL (B). Study parameters included residual refractive astigmatism, rotational stability. Higher order aberrations included spherical aberration, coma, trefoil and Strehl ration measured by optical path difference scanning system (OPD scan III, NIDEK Co Ltd) through mesopic pupil. All measurements were documented 3 months postoperatively
Results
A total of 46 eyes were included and divided equally into groups (A & B). Mean mesopic pupil diametere was 5.03±0.27mm in group A and 5.11±0.32mm in group B, p >0.05. Average residual refractive astigmatism was 0.32±19 and 0.38±21 diopter in groups A & B respectively (p >0.05). Absolute IOL rotation was 3.17±2.92 degrees in group A while was 3.12±2.71 degrees in group B. Total spherical aberration was -0.006±0.07μ in group A, and 0.11±0.06 μ in group B, P<0.05. Total ocular coma and trefoil were higher in group B without statistical significant difference. Strehl ratio was higher in group A without statistical significant difference.
Conclusion
Both IOLs showed promising astigmatic correction with excellent postoperative rotational stability and centration within the capsular bag. Although in group A, total spherical aberration was significantly lower and Strehl ratio was higher, further studies to include subjective contrast sensitivity (CS) are warranted to compare visual quality of both lenses.