EyeWorld Asia-Pacific September 2016 Issue

September 2016 EWAP NEWS & OPINION 69 continued on page 8 the patient for his or her refractive history,” he said. “So many patients have had LASIK, and this will affect your calculation. You might want to screen the patient’s topography.” Dr. Fam further recommended a thorough clinical examination— check the anatomic ocular status, for instance in terms of media changes, retinal detachment, and macular changes. In addition to these pearls, Dr. Fam presented a comparison of various IOL formulas in atypical eyes—not eyes that have undergone prior refractive surgery but “virgin eyes” that are long, short, steep, flat, or have low/negative diopters. Through a series of cases, he demonstrated the necessity of using special constants or Koch’s axial length adjustment when using standard formula for atypical eyes. His series also demonstrated the value of using the Barrett True-K and Universal II formulas. Manual small incision cataract surgery technique, pearls, and advantages A MasterClass on manual small incision cataract surgery (MSICS) delved into each aspect of the procedure from start to finish. Attendees learned about wound construction, anterior capsulotomy, nucleus management, capsulectomy, and IOL implantation, as well as situations where this technique might be preferable to phacoemulsification surgery. Course director Sanduk Ruit, MD , Kathmandu, Nepal, led the class with faculty that included Anuchit Poonyathalang, MD , Bangkok, Thailand, Ganesh Raman, MD , Coimbatore, India, and Nikolle Tan, MD , Singapore. “Because of the backlog of cataract, cataract continues to be the most prevalent cause of blindness,” Dr. Ruit, who is credited with first developing MSICS, said in his presentation leading the MasterClass. Showing a couple of videos highlighting the technique, Dr. Ruit briefly described the process but emphasized to attendees that he and his faculty would go through the process several times so “by the time we finish our course, you’ll be quite conversed with the basic principles of small incision cataract surgery.” Dr. Tan got into more detail on MSICS in her presentation, focusing on wound construction. “We will soon realize that wound construction is the foundation of the surgery,” Dr. Tan said. “When we make the wound, first of all, we want to make it self-sealing. Other things we want to consider are the size and hardness of the nucleus and the lens we’re putting in.” Before deciding to perform MSICS, Dr. Tan noted that one has to evaluate the status of the sclera, excluding patients with scleral thinning. Dr. Tan said the external incision is relatively short with a long tunnel that ends in a large internal incision, resulting in a trapezoid-shaped wound. The external incision, which ranges between 5 and 8 mm in size, is important “because it stretches to allow for the delivery of the nucleus and allows you to insert the intraocular lens.” A frown- shaped incision results in minimal surgically induced astigmatism, but Dr. Tan said this curved shape can be difficult for those just learning the technique. She advised those starting out with MSICS use a Blumenthal incision, which is a straight incision with two oblique cuts at the end. When it comes to the scleral tunnel, Dr. Tan said the optimal scleral flap thickness is about 0.3 mm. Too thin of a flap could result in a tear or button hole, while too thick of a flap could result in premature entry. Creating continued on page 70 an optimal scleral tunnel can be aided by making sure the scleral bed is dry, using sharp crescent blades, and stabilizing the globe with toothed forceps rather than grasping the scleral flap. The internal aspect of the tunnel should be about 25% bigger than the external incision, Dr. Tan said, and the tunnel should be “uniform and complete for smooth nucleus delivery.” Dr. Tan also touched on complications that can occur with MSICS. A button hole in the scleral flap, for example, can result from superficial dissection. Such a complication can be managed by deepening the incision and finding a deeper plane, starting at the opposite side of the button hole. Dr. Tan cautioned against over cautery as it could cause wound shrinkage and scleral melt. To reduce postop astigmatism, Dr. Tan recommended creating the wound at the steepest meridian and said the wound should only be as long as necessary. A longer wound could