Eyeworld

EW GLAUCOMA 62 May 2016 by Maxine Lipner EyeWorld Senior Contributing Writer The second case involved a patient who had allergies to 1 of his glaucoma medications—something his initial physician hadn't recog- nized. "The doctor gave the patient a prescription for a steroid eye drop, and the patient didn't come back for 4 or 5 months," Dr. Robin said. When he did return, his pressure was at 60 mm Hg and he had lost most of his vision. He stressed the importance of making sure patients understand that if they are taking steroids, they have to return for follow-up because Important considerations to keep in mind when treating glaucoma patients who may be steroid responders I t's one of those concerns practi- tioners have for their glaucoma patients—a steroid response that results in heightened intra- ocular pressure. EyeWorld honed in on what to remember when treat- ing glaucoma patients whose IOP may rise in response to steroids. While the connection between steroid use and the rise in intraoc- ular pressure in some patients is clear, what practitioners don't know is why this sometimes happens, ac- cording to Alan L. Robin, MD, pro- fessor of ophthalmology, University of Maryland, Baltimore, University of Michigan, Ann Arbor, Michi- gan, and associate professor, Johns Hopkins University, Baltimore. "We don't know the total answer, but we think that the steroids change the way the trabecular meshwork functions, and by doing that, they block the trabecular meshwork so that the egress of aqueous humor is more difficult," Dr. Robin said. The belief is, in part, that extracellular matrix materials are produced and that these in turn block the trabecu- lar meshwork, he explained. Barbara Smit, MD, clinical instructor, University of Washing- ton, Seattle, agreed that the mecha- nism for this all-too-common issue remains unclear. "About one-third of the population, whether they have glaucoma or not, is at risk of having a pressure elevation with exposure to steroids," she said. "The mecha- nism of that is not well understood." There are a number of theories about genes that are turned on and how this may result in changes in the turnover of cells in the materials of the trabecular meshwork. What's more, those with glaucoma seem predisposed to a steroid response. Dr. Smit thinks that more than one- third of the glaucoma population is at risk for such a steroid response. While Dr. Robin concurs that this is more common in glaucoma patients, it is something that could affect anyone, he stressed. "My guess would be that almost anyone given enough steroids in the right route would get a steroid response." If a patient is found to have a steroid response in 1 eye, he or she will usually develop the same thing in the other, Dr. Robin finds. "It's usually a person response, not an eye response," he said. Likewise, the patient is apt to develop a steroid response again in the eye if chal- lenged again at a later point. Still, Dr. Robin said that practitioners need to be sure that it is indeed a steroid response they are seeing. He cited patients who have uveitis who are treated with steroids because these reduce inflammation in the eye. "Often one isn't sure if it's the underlying uveitis that caused the pressure to elevate or whether it was the secondary steroid they were given that caused the pressure to ele- vate," he said. One trick here would be to treat the fellow eye, which is not inflamed, with steroids and if the pressure goes up, the physician knows it's a steroid response, Dr. Robin noted. While he finds that the steroid response goes away, care is needed with such a tactic. "You have to tell patients what you're doing and follow them carefully because you don't want to give them a ste- roid response that will cause them to lose vision," he said. The same is true for patients who are put on steroids for a chron- ic condition such as blepharitis. Dr. Robin recalled a couple of cases he came across early in practice where patients on steroids were not effectively monitored. "One was a gentleman with blepharitis who was given a prescription for a steroid antibiotic combination," he said. "The patient was lost to follow-up and 6 months later came back with a pressure in the 40s and had lost half of the vision in his eye because of the glaucoma." High IOP anxiety Practitioners should closely follow glaucoma patients who are taking steroids, with good baseline documentation of their IOP and optic nerve appearance. Source: Alan L. Robin, MD continued on page 64 Pharmaceutical focus Dr. Robin stressed that steroids have good and bad attributes. " You have to make sure that patients understand the reason that you use them. "

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