Eyeworld

EW CATARACT 27 December 2018 tunnel incision, dissecting it ante- riorly into clear cornea with a cres- cent blade. He finds the can-opener capsulotomy useful after staining, especially because of the comor- bidities generally associated with these cases. Dr. Chang hydrodissects the nucleus with irrigation from a Simcoe I/A tip, which he also uses to help extract the nucleus and remove cortex. Dr. Chang will usually im- plant a large optic PMMA IOL, such as the CZ70BD (Alcon, Fort Worth, Texas), and will often close the inci- sion with a single interrupted 10-0 nylon suture. Dr. Oliva finds that if the wound is carefully constructed, there is typically no need for a suture, though one can be placed if the surgeon is worried about induc- ing excessive astigmatism, especially with superior incisions. Using a dia- mond crescent blade, which he said makes the smoothest tunnels and improves wound closure, Dr. Oliva creates a straight partial thickness groove 1 mm posterior to the lim- bus approximately 7 mm in length. Dissection is then carried out within the sclera into clear cornea for 1–2 mm before entering the eye. He said the internal diameter of the incision should be created with a keratome and measure close to 10 mm to give the wound a funnel shape. For the capsulotomy, Dr. Oliva said he finds the V-capsulotomy best suited for dense cataract cases with small pupils. "Early in training, I advise vis- coelevation of the nucleus into the anterior chamber prior to delivery from the eye," Dr. Oliva said. "Make sure it is above the iris, especially inferiorly, and make sure the wound is large enough. Always protect the endothelium with viscoelastic prior to delivering the nucleus. An irrigat- ing lens loupe can be helpful early in the learning curve." If he's dealing with a case of very small pupils, Dr. Oliva will often create several microsphincter- otomies with Vannas scissors, which he said can facilitate the delivery of a large nucleus through a smaller pupil with minimal cosmetic effect postop. In a case of inadequate dilation, Dr. Schallhorn cautioned against using a Malyugin ring in favor of hooks instead. "A ring will prevent you from prolapsing the lens up and can get caught on the lens loop," she said. At the end of the case, Dr. Oliva closes the conjunctiva with a tem- poral incision using cautery; with a superior incision there is generally no need to close the conjunctiva as it covers the incision naturally, he added. Dr. Schallhorn said it is import- ant to make the internal dimensions of your incision wider than external dimensions; this creates a funnel to help mold the lens as you remove it. Dr. Schallhorn places the apex of the frown 1 mm posterior to the limbus with the tails of the frown 2 mm posterior to the limbus for a total incision that is 8 mm long. After creating the frown incision she tunnels forward just into the clear cornea, fanning out the in- ternal portion of the wound until it is about 11 mm wide. Once the tunnel is complete, she opens the central portion with a keratome and creates a can-opener capsulorhexis before opening the entire incision, maintaining a stable chamber. At the end of the case, after placing a three-piece IOL, Dr. Schallhorn will put in one figure-of-eight suture, even though the tunnel should be self-sealing. She closes the conjunc- tiva with a Vicryl suture (Ethicon, Bridgewater, New Jersey) or with forceps cautery. Converting from phaco to MSICS mid-case, cases to avoid, and beyond As previously mentioned, MSICS can be a valuable technique if phaco is not working for a case, such as if there appears to be zonular weak- ness or risk of the nucleus dropping. Dr. Schallhorn said the switch is pretty easy and starts with anesthe- sia. If you're using topical anesthe- sia, you'll want to give the patient a block, she said. Then, suture the main wound and move your micro- scope superiorly, while there is some viscoelastic in the eye to prevent hypotony. Dr. Oliva said it is possible to re- main sitting temporally and create a scleral tunnel beneath and posterior to the 2.2-mm clear corneal tempo- ral phaco incision, but the trick is to not join the two wounds. There are also cases where MSICS should be avoided. Dr. Oliva said he avoids this technique in those who have had glaucoma sur- gery and those who need combined surgery, such as a cataract DSAEK case. Dr. Schallhorn said patients with gross phacodonesis are general- ly not good candidates as well. In general, Dr. Schallhorn said she thinks "there is definitely a place for MSICS" in training pro- grams as well as in practice, even in developed countries. "We are fortunate in the U.S. to have a hugely diverse patient population, both medically and geo- graphically," she said. "We see many recent immigrants with extremely dense lenses who are good MSICS candidates, and also many patients with complex medical problems that have led them to be good can- didates for MSICS," Dr. Schallhorn said. EW References 1. Chen CK, et al. A survey of the current role of manual extracapsular cataract extraction. J Cataract Refract Surg. 2010;36:692–3. 2. Lynds R, et al. Supervised resident manual small-incision cataract surgery outcomes at large urban United States residency training program. J Cataract Refract Surg. 2018;44:34–38. Editors' note: The physicians have no financial interests related to their comments. Contact information Chang: dceye@earthlink.net Oliva: moliva@cureblindness.org Schallhorn: jschallhorn@gmail.com Extracted nucleus following sphincterotomies, can-opener capsulotomy, and MSICS through a scleral pocket temporal incision Incision closed with a single 10-0 nylon suture Source (all): David Chang, MD

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