EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.
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EW FEATURE 80 Complex cataract cases October 2014 • Dislocated natural lenses or IOLs can have a number of causes, including trauma, congenital conditions, high myopia, hypermature cataracts, or older 10-0 Prolene suture use. • Surgeons may see more dislocated IOLs as patients with pseudoexfoliation live longer. • The surgical approach to fix a dislocated lens or IOL can vary greatly depending on the exact problem and surgeon's preference. • Some familiarity and training with a pars plana approach is helpful for anterior segment surgeons. by Vanessa Caceres EyeWorld Contributing Writer Fixing dislocated lenses and IOLs AT A GLANCE Anterior segment surgeons need tools, techniques to tackle this challenge D islocated natural lenses and IOLs require constantly evolving tools and surgical approaches. The causes behind a dislocated natural lens or IOL can vary, said Minu Mathen, MD, senior consultant, cataract and re- fractive surgery services, Chaithanya Eye Hospital & Research Institute, Trivandrum, Kerala, India. "In my experience, the common causes of dislocated or subluxated natural lenses are congenital causes, pseudoexfoliation, trauma, and hypermature cataracts," Dr. Mathen said. "With IOLs, the causes are im- plantation without adequate capsule support, placement of haptics into the area of zonular dehiscence, pseudoexfoliation, trauma, high myopia, retinitis pigmentosa, and in post-vitrectomized eyes." Other causes include a hyper- mature cataract, megalophthalmos, and any other cause of preoperative phacodonesis, said Soosan Jacob, MS, FRCS, DNB, senior consultant ophthalmologist, Dr. Agarwal's Eye Hospital, Chennai, India. Surgeons also see cases where 10-0 Prolene was used as the suture to keep a prosthetic element at- tached to the sclera, said Richard S. Hoffman, MD, clinical associate professor of ophthalmology, Casey Eye Institute, Oregon Health & Science University, Eugene, Ore. Fast forward 7 to 10 years later, subluxation occurs. "We now use Gore-Tex or 9-0 Prolene. Gore-Tex won't break, and no one has report- ed 9-0 Prolene breaking yet," Dr. Hoffman said. A study published last year involving 61 eyes found that high myopia was a common cause of late in-the-bag IOL dislocation. 1 Anterior segment surgeons may see dislocation more frequently in the future. "I think we'll see more of these cases as patients with pseudo- exfoliation live longer. Not everyone has this happen, but the longer they live, the greater the chance of the lenses coming loose," Dr. Hoffman said. Surgical approaches The surgical approach to a dislocat- ed natural lens or IOL depends on what has happened in the eye and the surgeon's preference. Here's how Drs. Mathen, Hoffman, and Jacob handle these cases. For an IOL completely dislo- cated into the vitreous, Dr. Mathen calls an in-house vitreoretinal surgeon to perform a pars plana vitrectomy and bring up the IOL. When there is good capsule support and a multi-piece IOL, he places the IOL in the ciliary sulcus. With no capsular support, he places the haptics exteriorly via sclerotomies placed under a partial- thickness scleral flap and tucks them into scleral pockets. He then remains sutureless by closing the scleral flaps with fibrin glue For a single-piece IOL, Dr. Mathen will bisect and explant the IOL and then perform sutureless scleral fixation as described above. "If there's a single or multi-piece IOL and the whole capsular bag with or without a capsular tension ring Figure 1: CTR and IOL in the bag subluxated Figure 3: Capsular bag stripped off the IOL Figure 2: CTR explant after snipping bag near eyelet Figure 4: Optic captured above iris