Toric intraocular lenses (IOLs) have become an increasingly common technique due to their advantage of predictably, stably, and safely correcting a preexisting astigmatism. Significant postoperative astigmatism might affect both vision quality and spectacle independence, leading to unsatisfactory outcomes. Corneal astigmatism management has become crucial in modern cataract and refractive surgery practices. Also, 21.3–22.4% of patients with cataracts have 1.0–1.5 D of corneal astigmatism with 10.6–12.4% of patients having 1.5–2.0 D and 8.2–13.0% of patients having 2.0 D or more.
#Itrace toric lens alignment trial
Trial registrationĬurrent Controlled Trials ISRCTN94956424, Retrospectively registered (Date of registration: 05 February 2020).Īn estimated 40–50% of the population aged over 60 years has more than 1.0 diopter (D) of keratometric astigmatism. The findings show that use of iTrace built-in toric calculator is safe and effective for planning toric IOL surgery for wavefront keratometric astigmatism. This is the first study on evaluation of clinical outcomes of toric IOL implantation in corneal astigmatism patients using iTrace wavefront keratometric readings. The proportion of astigmatism ≤0.50 D increased from 0 to 71.8% postoperatively. Surgical induced astigmatism was 1.73 D ± 0.77 and the mean correction index was 0.89 ± 0.22, showing a slight undercorrection. Postoperative mean refractive astigmatism decreased significantly to 0.48 D ± 0.34. Preoperative mean corneal topographic astigmatism was 1.91 diopters (D) ± 0.69 (standard deviation). Astigmatic changes were assessed using Alpins vector method over a 3-month follow-up period.
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The IOL power and cylinders were chosen with the help of the iTrace toric planning program using wavefront keratometric astigmatism. The study included 85 eyes of 63 patients undergoing phacoemulsification and toric IOL implantation. Setting: Single site in China, Shanxi Eye Hospital, Shanxi, China. This aim of this study was to evaluate visual outcomes and rotational stability after toric intraocular lens (IOL) implantation using the wavefront aberrometry of the cornea with iTrace. It was supposed to be more accurate than iTrace simulated keratometry which was calculated based on only 4 points on the circle of 3 mm. The iTrace wavefront aberrometry of cornea calculated steep power and axis based on the best Zernike mathematical fit from all topo data within 4 mm circle.
#Itrace toric lens alignment manual
It can eliminate the potential systematic errors resulting from varying head positions during the preoperative keratometry measurement and from manual marking.Currently, there is no standard technique for determining corneal astigmatism. The mean toric IOL misalignment was lesser but without significance in the TRP marking group than in the SHM marking group after 3 postoperative months (2.66° ± 1.42° versus 3.29° ± 1.67° P =0.295).Ĭonclusion: The TRP marking method using the iTrace aberrometer is simple and accurate for preoperative marking of toric IOLs.
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There was no statistically significant difference in BCVA, UDVA, preexisting corneal astigmatism, or residual astigmatism between the groups before or after surgery ( P > 0.05). Results: Fifteen eyes of 15 patients were in the TRP marking group and 15 eyes of 15 patients in the SHM marking group. The follow-up duration was 3 months after cataract surgery. TRP marking involved marking three points randomly in the corneal limbus of the patients and accurately marking the horizontal meridian was not required. All patients were prospectively randomized into the TRP marking group or slit-lamp horizontal meridian (SHM) marking group. Method: Thirty eyes of 30 patients undergoing cataract surgery with coexisting corneal astigmatism of over 1.0 D were included in this study. Department of Ophthalmology, Guangdong Eye Institute, Guangdong Academy of Medical Sciences, Guangdong Provincial People's Hospital, Guangzhou, China.ĭesign: Prospective, randomized comparative trial. Purpose: To evaluate the clinical outcome of the three-random-point (TRP) marking method for toric intraocular lens (IOL) alignment using the iTrace aberrometer (Tracey Technologies Corp., Houston, TX).