Eyeworld

EW CATARACT 30 June 2017 by Stefanie Petrou Binder, MD, EyeWorld Contributing Writer Of the 189 with-the-rule astigmatism eyes, 43.3% resulted in overcorrections of more than 0.5 D, and 11.1% resulted in overcorrec- tions of more than 1.0 D. Undercor- rections of more than 0.5 D were seen in 0.5% and undercorrections of more than 1.0 D in none of the study eyes. "There was more overcorrec- tion than undercorrection for all toric IOL powers, with the highest overcorrections occurring in eyes receiving the highest toric IOL powers. Also, less astigmatism was noted postoperatively at 0.50 ± 0.45 D, compared to preoperatively at 2.56 ± 1.09 D (P<.001). The mean correction index, calculated using vector analysis, was 1.22 ± 0.20. The correction index is the ratio between the aimed correction of the preexis- tent astigmatism and the achieved correction. Ideally, the correction index is 1.0. A ratio higher than 1.0 reflects an overcorrection, whereas a ratio below 1.0 reflects an undercor- rection. Overcorrection was associat- ed with a flipping of the astigmatism axis postoperatively," Dr. Webers said. In the 79 eyes with against-the- rule astigmatism, overcorrections of more than 0.5 D were noted in 7.6% of eyes and overcorrections of more than 1.0 D in 2.5% of these eyes. Only 2% of against-the-rule eyes had undercorrections of more than 0.5 D, and none were overcorrected more than 1.0 D. "There was less overcorrection in the against-the-rule group as com- pared to the with-the-rule group, with the highest percentage of overcorrection seen in SN6AT9 eyes. Less astigmatism was noted postop- eratively at 0.62 ± 0.68 D versus pre- operatively at 2.29 ± 0.97 D (P<.001) in these eyes. The mean correction index was 1.01 ± 0.19. In eyes with no overcorrection, the astigmatism axis did not flip," he said. Technology and biometry are key Another poster presentation at the meeting evaluated the visual and optical performance of eyes implant- ed with the trifocal IOL AT LISA tri 839MP (Carl Zeiss Meditec, Jena, Germany). "A general overcorrection was seen in with-the-rule eyes, which might be explained with the use of a first generation toric calculator neglecting the posterior corneal astigmatism," said Valentijn Webers MD, University Eye Clinic of Maas- tricht, the first author of the study, who presented his work. "Secondary treatments like IOL repositioning, additional LASEK, and IOL exchang- es were required in a small percent- age of cases." Complications and management Dr. Webers reported that 276 of the study eyes (89%) had a misalign- ment of less than 5 degrees, 20 eyes (6%) were misaligned by 5–10 degrees, and 14 eyes (5%) by more than 10 degrees. Only 13 eyes (4%) underwent a secondary surgical treatment: realignment in seven eyes (2%), IOL exchange in four eyes (1%), and laser touch-up in two eyes (1%). derwent cataract extraction and phacoemulsification followed by toric IOL implantation between June 2013 and June 2016. The study involved the VERION Image Guided System (Alcon) for toric IOL align- ment, the AcrySof Toric Calculator (first generation, Alcon) for toric IOL power determination, and implan- tation of the AcrySof IQ toric IOL SN6AT3-9 in more than 95% of the study eyes. Preoperatively, the mean anteri- or corneal astigmatism was –2.45 ± 1.16 D, and the mean posterior cor- neal astigmatism was –0.46 ± 0.27 D. Sixty-one percent of eyes had with- the-rule astigmatism, and 25% had against-the-rule astigmatism. Postoperatively, the mean residual refractive astigmatism was –0.57± 0.56 D, and the mean uncorrected distance visual acuity was 0.12 ± 0.18 logMAR. The mean postoperative misalignment was 3.3 ± 3.7 degrees. New toric IOL and trifocal IOL studies presented at the 21st Winter Meeting of the ESCRS demonstrate the benefits of cutting-edge technology T he AcrySof IQ toric IOL SN6AT3-9 (Alcon, Fort Worth, Texas) is highly effective in the treatment of preexistent corneal astigmatism in patients undergoing cataract surgery, according to the outcomes of a new Dutch study that was presented as a poster at the 21st Winter Meeting of the European Society of Cataract and Refractive Surgeons (ESCRS), in Maastricht, Holland. The study demonstrated residual astigmatism of roughly –0.5 D and postoperative misalignments of around 3 degrees. The 3-year toric IOL cohort study included 310 eyes that un- Cutting-edge technologies and better outcomes Presentation spotlight continued on page 32 The optical zone of the AT LISA tri toric 939MP. It has fewer rings on the IOL optic surface for reduced potential visual disturbances and improved night vision. The near addition is +3.33 D for comfortable reading distance. The intermediate addition is +1.66 D, which does not compromise near or distance vision. Source: Matteo Piovella, MD

• Blank Page
• Blank Page (1)