Eyeworld

EW REFRACTIVE 52 June 2018 may be something to think about. Intrastromal femtosecond astigmatic keratotomy leaves the epithelium and Bowman's layer intact. There is less risk of infection and wound problems, and minimal discomfort," he said. EW References 1. Taban M, et al. Acute endophthalmitis following cataract surgery: a systematic review of the literature. Arch Ophthalmol. 2005;123:613–20. 2. Simsek S, et al. Effect of superior and temporal clear corneal incisions on astigma- tism after sutureless phacoemulsification. J Cataract Refract Surg. 1998;24:515–8. 3. Fine IH, et al. Profile of clear corneal incisions demonstrated by ocular coher- ence tomography. J Cataract Refract Surg. 2007;33:94–7. Editors' note: Dr. Muftuoglu has no financial interests related to his comments. Contact information Muftuoglu: orkun.muftuoglu@gmail.com shoulder width, among other char- acteristics. He prefers blades with a minimal front-end resistance, for easy penetration but with resistance that increases gradually with tissue passage, giving the surgeon more control. Incision shape The best wound healing results from an incision with a good configura- tion. A square incision will poten- tially cause less astigmatism than a rectangular incision. CCI tunnels that are too short may leak, allow iris prolapse, may need extra stromal hydration or sutures, and even take longer to heal. A longer tunnel, on the other hand, may cause striae, less maneuverability, and sometimes wound burn. Proper incision archi- tecture increases the stability and safety of the wound and reduces the possibility of induced astigmatism. Incisions in the corneal plane with a chord length of at least 2 mm pro- vide an advantageous architecture for adequate self-healing, according to study outcomes. 3 "Pressures can affect our wounds. Endothelial gaping can result from low IOP, which often leads to anterior chamber contami- nation. The IOP should not be low at the end of surgery," Dr. Muftuog- lu said. "Multiplanar incisions allow the wound to automatically adjust to high or low IOP. With low IOP, the vertical walls of the incision may collapse and promote wound seal- ing. With higher IOP, the horizontal walls stick together, securing the wound." Astigmatic correction When needed, additional corneal in- cisions can be strategically placed at the time of cataract surgery to help reduce astigmatism. "Astigmatic correction can be achieved through the placement of incisions on the steep meridian, like relaxing inci- sions (astigmatic keratotomy, limbal relaxing incisions), with toric IOLs, and bioptics (excimer laser or other keratorefractive modality)," Dr. Muf- tuoglu said. "Astigmatic keratotomy has made a comeback after femto- second technology. They are placed closer to the center, which has a higher effect, however, may also cause irregular astigmatism, especial- ly if done manually. Limbal relaxing incisions are placed more peripheral- ly and are less likely to cause a shift in the resultant cylinder axis. They are easier to perform, technically, and patients generally report less discomfort. Also, the coupling ratio is negligible, so you don't need to adjust the IOL power." Dr. Muftuoglu observed from his own studies that undercorrection was frequent with limbal relaxing incisions and regression possible, especially if very vascularized. LRIs are best reserved for low astigmatism correction, under 1.5 D, otherwise predictability tends to drop. LRI complications can include infection, weakening of the globe, perforation, decreased corneal sensation, dry eye, and induction of irregular astigma- tism and axis shift. Dr. Muftuoglu thinks that femtosecond laser incisions are a promising new modality for the cor- rection of astigmatism during cata- ract surgery. "The femtosecond laser has changed the standard. Femto astigmatic keratotomy, for instance, allows greater precision in incision length, depth, and angle. The cost Incisions continued from page 50

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