EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.
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EW FEATURE 44 Secondary glaucoma challenges May 2015 AT A GLANCE • Pigmentary glaucoma is a hereditary condition most often seen in younger, myopic Caucasian males. • Cataract removal may help the condition by fixing the refractive error and changing the shape of the iris. Surgeons should follow pearls to ensure a smoother surgery. • Selective laser trabeculoplasty can be performed with caution in patients with pigmentary glaucoma. Argon laser trabeculectomy is more effective in younger patients. Trabeculectomy and tube shunts are also options. • MIGS procedures are becoming more common in these patients when they can sufficiently l wer IOP. by Vanessa Caceres EyeWorld Contributing Writer and director, Montreal Glaucoma Institute, recommends that those with pigmentary glaucoma have their siblings or children examined, especially if they are myopic. Dr. Harasymowycz finds that younger, active patients are more likely to experience a "pigment storm," leading to a sudden increase in the number of pigment granules that can be associated with an IOP spike and a secondary blurring of vision. "In these patients, we some- times ask them to run up and down a flight of stairs at the office and se if we can exhibit this phenomenon, especially if present on history," he said. It is important for glaucoma specialists to distinguish between primary and secondary pigment dispersion, Dr. Harasymowycz said. "In secondary pigment dispersion, the lens must be dealt with if one wants to avoid progressive pigment shedding," he said. A careful differential diagnosis is also crucial, said Brian A. Francis, MD, professor of ophthalmology, Doheny Eye Institute, University of California, Los Angeles. Other conditions that might appear similar include pseudoexfoliation syn- drome, uveitic glaucoma, and ocular tumors, he said. "If someone has an iris melanoma, that releases pigment that can mimic pigmentary glauco- ma, especially if it is unilateral," he said. Pigmentary glaucoma and cataract surgery The need to perform cataract surgery in patients with pigmentary glaucoma may not be common, as they tend to be younger. However, medical therapy may accelerate the development of cataract, Dr. Harasymowycz said. "In some ways, with modern cataract surgery, you can argue that you'd have a lower threshold for doing cataract surgery because one, you can fix the refractive erro , and two, you can change the way the iris is contacting the lens and the struc- tures behind it," Dr. Noecker said. He sees value in performing a la- ser iridotomy and cataract surgery to stop a large amount of pigmentary dispersion. "If the patient is still in a phase where pigmentary dispersion is causing damage, it's good to alter the course of that," he said. Patients with pigmentary dis- persion syndrome may be helped by the irrigation and aspiration during cataract surgery, with the subsequent "washing out" of the trabecular meshwork pigment, Dr. Harasymowycz said. Dr. Ritch cautions against clear lens extraction in these patients as they tend to be young. If cataract surgery is necessary, Dr. Francis shares the pearl of avoid- ing reverse pupillary block during surgery by putting an instrument under the iris at the pupil and tenting it up as irrigation is turned on. This will help make the anterior chamber stable. Surgeons should also inform these patients that they are at a higher risk for retinal detachment post-cataract surgery. When Dr. Harasymowycz observes that the posterior vitreous face is still attached to the retina via optical coherence tomography or when peripheral retinal changes are noted during a preop exam, he will often send the patient to a retina colleague, who can evaluate the necessity of pretreating certain areas with a laser. "This also serves as an import- ant step in potential future medico/ legal situations that may arise if complications do occur," he said. Treating pigmentary glaucoma The treatment for pigmentary glau- coma tends to vary according to the patient and the surgeon—there is no one go-to procedure, Dr. Francis said. "In general, it's somewhat more difficult to control than open angle glaucoma, but we still use the same types of medications and surgeries," he said. Although laser trabecu- loplasty is an option, surgeons have to be mindful of pressure spikes because there is a lot of pigment in the angle, and the laser energy is taken up more easily. "You have to use a lower power and consider do- ing a lesser number of shots. Instead of doing 360 degrees, you may do 180 degrees," Dr. Francis said. Then, watch the patient and see if the procedure needs to be repeated at a later time. In the latter situation, Dr. Harasymowycz advises remeasuring the IOP 30 to 45 minutes after laser, Pearls for care in pigmentary glaucoma Subset of disease is not always easy to diagnose or treat A lthough pigmentary glau- coma is not as common as other forms of primary open angle glaucoma, specialists still tend to see it regularly and must choose the best treatment. "It's one of those things that the more you look for it, the more you find it. The trick is it can be very subtle, especially earlier on," said Robert J. Noecker, MD, clinical assistant professor, Yale University, and in private practice, Ophthalmic Consultants of Connecticut, Fairfield, Conn. Pigmentary glaucoma classically appears in younger, myopic males. It can develop as young as the late teens or early 20s, said Robert Ritch, MD, Shelley and Steven Einhorn Distinguished Chair, professor of ophthalmology, New York Eye and Ear Infirma y, New York. Dr. Ritch pioneered much of the early re- search into pigmentary glaucoma, and he has previously reported that it is seen in 2.45% of the Caucasian population. The condition is often hereditary, which is why Paul Harasymowycz, MD, chief of glaucoma, University of Montreal, continued on page 46 Krukenberg's spindle, showing pigment dispersion in a typical pattern on the corneal endothelium Source: Robert J. Noecker, MD