EyeWorld India March 2019 Issue

14 EWAP FEATURE • September can be better than the manual LRIs but this is only up to 1.0 D of astigmatism. After that, the toric IOLs are far better than femto AKs.” Dr. Donnenfeld noted that intrastromal incisions performed with a femtosecond laser are not painful and do not require postop antibiotics. Dr. Devgan avoids using AKs if the cornea is thin or irregular. He also avoids them with eyes that have asymmetric astigmatism. Dr. Donnenfeld urged caution in using AKs in patients with irregular astigmatism, as well as those with ectasia or dry eye disease. Effective treatment range The degree of astigmatism AKs can correct include high levels of astigmatism, but in such eyes, the incisions also induce irregular astigmatism and dry eye, Dr. Donnenfeld said. “In the past, it was routine to correct 3 D of cylinder or more with an AK,” Dr. Donnenfeld said. “Today, toric IOLs and excimer laser ablation are better options for high levels of astigmatism, and we generally perform astigmatic keratotomies for 1.5 D or less of cylinder.” Dr. Devgan has found about 0.5–1.0 D to be the ideal treatment range for AKs. “More can be done but it is less accurate and less predictable,” Dr. Devgan said. Normal healing time for AKs include epithelial closure within 48 hours, but stromal remodeling may take several months, Dr. Donnenfeld said. Dr. Devgan has also found the epithelium closes within a day or two for both AKs and LRIs. “The effect starts immediately but may take a week or two to stabilize,” Dr. Devgan said. Regression possible? In general, astigmatic incisions do not regress, Dr. Donnenfeld said. “In fact, they may progress over time,” Dr. Donnenfeld said. “Progression is much more common with larger incisions, and for incisions of 1.5 D or less, it is generally minimal.” Dr. Devgan has found that at larger attempted corrections, regression is more common. “But at 1.0 D or less, it is fairly stable over years,” Dr. Devgan said. EWAP Editors’ note: Dr. Devgan has financial interests with LensGen (Irvine, California), IOLcalc.com, and CataractCoach. com. Dr. Donnenfeld has financial interests with Alcon (Fort Worth, Texas), Johnson & Johnson Vision (Santa Ana, California), Katena (Denville, New Jersey), and Bausch + Lomb (Bridgewater, New Jersey). Contact information Devgan: devgan@gmail.com Donnenfeld: ericdonnenfeld@gmail.com A patient undergoes a manual LRI in the OR. A patient undergoes a manual LRI at the slit lamp. Source (all): Eric Donnenfeld, MD Greenwood said. “I also like torics in the lower astigmatism range (1.0–1.5 D) because we are less dependent on patient healing and the response of the cornea to the incisions,” he said. “The other great thing about toric IOLs is with the intraoperative aberrometry I can take a measurement after I have made my cataract incisions and get real time feedback from the aberrometry to show me the steep axis and exactly where to place the IOL.” Physicians have learned that for each degree they are off axis, they lose 3% of the power of the toric, Dr. Greenwood said, adding that this may not be much on a lower powered toric, but in a high powered toric, that can be a big difference if off just a few degrees. EWAP Editors’ note: Dr. Greenwood has financial interests with Alcon. Dr. Baartman, Dr. Miller, and Dr. Yeu have no financial interests related to their comments. Contact information Baartman: brandon.baartman@vancethompsonvision.com Greenwood: michael.greenwood@vancethompsonvision.com Miller: kmiller@ucla.edu Yeu: eyeulin@gmail.com Correcting corneal - from page 12 Views on astigmatism – from page 13 March 2019