Abstract
Purpose: :
It is reported that 15-20% of cataracts patients have preexisting corneal astigmatism greater than 1.5D. Since its FDA approval in 2005, AcrySof Toric intraocular lens have been selectively used to correct pre-existing corneal astigmatism at the time of cataract surgeries. The purpose of our study is to evaluate the results of AcrySof Toric lens implantation by a single surgeon and to share the author’s peri-operative experiences with the Toric Lens Implantation.
Methods: :
A non-randomized retrospective chart review was conducted on 71 eyes which underwent cataract surgeries with AcrySof Toric Lens implantation by a single surgeon at the University Of British Columbia/Vancouver General Hospital Eye Care Center between 2008 and 2009. These patients had a complete preoperative ophthalmic exam, including measurement of Snellen uncorrected visual acuity (UCVA), Snellen best corrected visual acuity (BCVA), autorefractometry (Nidek ARK 900A), corneal topography (Zeiss Altas 9000), and keratometry measured by the IOL-Master (Carl Zeiss Meditec AG). Pre-operative measurement of these different modalities are compared. Subgroup (SN60T3 = T3, n=30; SN60T4 = T4, n=20, SN60T5 = T5, n=21) analysis was performed. Surgically induced astigmatism(SIA) was also calculated using 10 step Holladay method.
Results: :
The cumulative preoperative cylinder K (n=58) measured by autorefractometry, corneal topography and IOL-Master were 110.50D, 103.30D, and 126.95D respectively. Average pre-operative UCVA was 20/103 and the average post-operative UCVA was 20/31. The postoperative mean UCVA for T3, T4 and T5 groups were 20/27, 20/30, and 20/38 respectively. The Average SIA using standard 2.75mm keratome was 0.485(n=13).
Conclusions: :
Corneal cylinder measured by IOL-Master tended to yield highest K values. Our calculation confirmed that the default SIA built into Alcon Toric IOL calculator was accurate. AlconSof Toric lens are reliable and effective in correcting pre-existing corneal astigmatism in cataract patients.
Keywords: astigmatism • cataract • intraocular lens