EyeWorld India December 2018 Issue

14 EWAP FEATURE September 2017 sue, so living tissue can change,” Dr. Doane said. “From everything we can tell with long-term results, in our centers and long-term data outside the U.S., the IOL remains stable.” He added that the cornea can change its astigmatism over time, and this will likely be what could change and alter the patients’ unaided vision. “My contention is that if the cornea doesn’t change then the result will be stable long term,” he said. Approved corrections Currently in the U.S., the LAL is approved for myopia, hyperopia, and astigmatism, alone or in com- bination, up to 2 D, Dr. Maloney said. In the future, the LAL can do as many corrections as there are patterns of light. At present, Dr. Doane said that ±2 D of sphere and 0.75–2 D of astigmatism are approved in the U.S. Outside the U.S., the treatments can be done to 3 D of sphere (plus or minus) and 3 D of astigmatism. Looking ahead, he said that any pattern could be possible. “My guess is that an extended depth of focus or multifocal pattern to resolve presbyopic complaints would be the next order of interest from surgeons and the company,” he said. The FDA approval was for postoperative adjustment of sphere and cylinder, Dr. Chang said. “This means that the [LAL] should become the ideal toric IOL for low to moderate astig- matism in my opinion,” he said. “Although we get excellent results currently, we still must estimate posterior corneal astigmatism and surgically induced astigmatism.” He added that low power toric IOLs are not available in the U.S. A study by Inoue et al. showed that 28% of the net mean toric IOL axis misalignment at 1 year was from surgical misalignment. 2 Dr. Chang added that even when using digital surgical alignment, a study from his practice showed that postop rotation of more than 5 degrees occurs between 8–18% of the time, depending on the IOL model. 3 Correcting the astigma- tism after several weeks postop- eratively circumvents all of these issues, he said. Dr. Chang thinks this new technology will help change the patient experience. “We will all welcome the improvement in refractive accuracy,” he said. “However, the biggest benefit will be the ability for patients to ‘try’ different pseudophakic refractive options postoperatively as a better way to decide what they want.” Having to decide whether they want better uncorrected distance, mid-range, or near vision preop- eratively is confusing and stress- ful for patients, he said. Without an IOL already in their eye, how can patients understand the dif- ference between being plano or –1.00? Or if they want to read without glasses, how can they decide between wanting –2.00 or –3.00? “Adjustable IOLs will allow patients to use trial lenses or even trial soft contact lenses to make this decision postoperatively,” Dr. Chang said. “We all know that mini-monovision is extremely popular for contact lens wearing presbyopes, largely because the anisometropia can be adjusted and can be reversed if it is not toler- ated.” He added that adjustable IOLs will give patients the ability to try out different amounts of pseudophakic anisometropia be- fore the cataract surgeon delivers this result with confidence. “For patients, so much of the stressful preoperative decision making will shift to the postoperative period, when an optometrist can explain and demonstrate the options in- stead of the cataract surgeon,” he said. “I think that patients, their referring optometrist, and their cataract surgeon will all be hap- pier with this arrangement.” EWAP References 1. Lundstrom M, et al. Risk factors for refractive error after cataract surgery: analysis of 282,811 cataract extractions reported to the European Registry of Quality Outcomes for Cataract and Refractive Surgery. J Cataract Refract Surg. 2018:44;447–452. 2. Inoue Y, et al. Axis misalignment of toric intraocular lens: placement error and postoperative rotation. Ophthalmol. 2017;124:1424–1425. 3. Lee BS, Chang DF. Comparison of the rotational stability of two toric intraocular lenses in 1273 consecutive eyes. Ophthalmol. March 2018. Epub ahead of print. Editors’ note: Dr. Chang and Dr. Maloney have financial interests with RxSight. Dr. Waltz and Dr. Doane have no financial interests related to their comments. Contact information Chang: dceye@earthlink.net Doane: jdoane@discovervision.com Maloney: info@maloneyvision.com Waltz: kwaltz56@gmail.com What to know – from page 13 D ce er 2018