Take-home: Aphakic eyes that have no or inadequate capsular support can pose a significant challenge to cataract surgeons. Careful attention to the preoperative considerations, appropriate intraocular lens choices, surgical techniques, and postoperative management can ensure optimal results.
Aphakic eyes that lack or have inadequate capsular support can pose a real challenge to cataract surgeons. The approach to these eyes has changed markedly in recent years, according to David Ritterband, MD.
Surgeons are moving away from the use of aphakic contact lenses and anterior chamber lenses, Dr. Ritterband reported, and toward the use of intraocular lenses (IOLs) that are placed precisely anatomically in the posterior chamber with fixation to the iris or sclera. He discussed the preoperative considerations and surgical management of these eyes.
Careful preoperative planning is the first step to successful exchange or replacement of IOLs. These considerations include the choice of anesthesia (peribulbar, retrobulbar, or general) and the actions to be taken with the IOL (IOL exchange, reposition, and method of fixation).
The IOL power calculation requires accurate biometry. The previous IOL power, if available, is a useful starting point in the power calculations. The important questions are the choice of iris or scleral fixation of the IOL and the target refraction, he commented.
Dr. Ritterband is system director of refractive surgery, Mount Sinai Health System; assistant director, Cornea Service, New York Eye and Ear Infirmary of Mount Sinai, and professor of ophthalmology, Icahn School of Medicine at Mount Sinai, New York.
The incision can be created in the superior or temporal cornea and the size can range from 2.75 mm to 3.25 mm. The surgeon can restrict the incision to 2.75 mm if he or she is using an injector to insert the IOL
A larger incision, ranging in size from 3.0 mm to 3.25 mm, is the appropriate choice when the surgeon needs to remove or exchange an IOL. An incision as large as 6 mm to 7 mm is needed when removing a non-foldable polymethyl methacrylate (PMMA) lens, an anterior chamber IOL, or a plate haptic IOL. The location and angulation of the paracenteses depends on surgeon preference, the location of the main wound, and the type of fixation (iris vs sclera).