Rotational stability of a single-piece toric acrylic intraocular lens

PURPOSE: To assess the rotational stability of a single-piece toric hydrophobic acrylic intraocular lens (IOL) during the first 6 postoperative months. SETTING: Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom. DESIGN: Prospective case series. METHOD: Eyes with age-related cataract and corneal astigmatism (1.00 to 3.00 D diopter [D]) were measured by partial coherence interferometry (IOLMaster). Preoperatively, the horizontal axis was marked. Surgical technique included a standardized temporal clear corneal incision, phacoemulsification, and in-the-bag implantation of a toric IOL (AcrySof SN60TT). Rotational stability of the IOL was assessed using retroillumination photographs postoperatively at 1 hour and at 1 and 6 months. Uncorrected (UDVA) and corrected distance visual acuities, residual refractive error, and keratometric and refractive cylinders were measured. RESULTS: The study enrolled 30 eyes (30 patients). The mean absolute IOL rotation was 2.44 degrees +/- 1.84 (SD) at 1 month and 2.66 +/- 1.99 degrees at 6 months. The photographic technique had high reproducibility of axis measurement, with consecutive measurements varying by less than 2.0 degrees. The mean UDVA was 0.16 logMAR (range 0.42 to -0.18 logMAR) at 1 month and 0.20 logMAR (range 0.60 to -0.20 logMAR) at 6 months. The residual refractive cylinder by autorefraction was -0.84 D (range -2.00 to 0.00 D) and -0.80 D (range -1.75 to 0.00 D), respectively. CONCLUSIONS: The acrylic toric IOL was rotationally stable within the first 6 months postoperatively. The photographic and axis analysis method to evaluate stability had high reproducibility and detected small changes in rotation.