Uveitic glaucoma a challenge

Orlando, FL-Uveitic glaucoma in children is a common complication of anterior uveitis that often coexists with cataract and band keratopathy.

Modern management can preserve vision and the patients' quality of life, noted Sharon F. Freedman, MD, who delivered the Marshall M. Parks Lecture during the annual meeting of the American Academy of Ophthalmology.

Thanks to the use of systemic non ster oid drugs, JIA no longer is a crippling and blinding disease in most cases. Some children with chronic anterior uveitis do well with no treatment, and others become blind despite treatment. Visual loss in these children results most commonly from cataract, band keratopathy, glaucoma (occurring in 25% to 40%), macular disease, amblyopia, and hypotony/phthisis, she explained.

Dr. Freedman recounted one study of elevated IOP and glaucoma secondary to chronic uveitis in children; researchers retrospectively studied 147 patients in which uveitis developed before age 16. Most patients (74%) had bilateral uveitis and were followed for 5 years, during which time 39% had elevated IOP and in 66% the elevated IOP developed less than 2 years after the onset of the uveitis. By 5 years, 20% of patients in the study had glaucoma, and ocular hypertension progressed to glaucoma in 59% by 5 years.

The study found that glaucoma was more common in association with JIA compared with other types of uveitis.

"The prevalence of secondary glaucoma in chronic anterior uveitis increases with the severity and duration of the uveitis," Dr. Freedman said. "The etiology of the glaucoma is multifactorial; the disease can be difficult to treat and often coexists with cataract and band keratopathy. Visual loss is common.

"Decreased aqueous outflow causes uveitic glaucoma rather than increased production," she said.

Less commonly, elevated IOP results from angle closure because of anterior or posterior synechiae.

"More commonly," she added, "the angle is open and almost normal in appearance. IOP becomes elevated from acute increased resistance in the trabecular meshwork, ster oid-related, or permanent changes in the meshwork."

Diagnosis and assessment

Measuring IOP is the most important step in recognizing uveitis-related glaucoma.

Identifying cells in the anterior chamber is the next step, as well as identifying other ocular effects of inflammation (such as band keratopathy, posterior synechiae, cataract, and keratic precipitates), Dr. Freedman noted.

When possible, she also recommended evaluating the angle using gonioscopy and checking the optic nerve for damage using slit lamp biomicroscopy or direct ophthalmoscopy rather than indirect ophthalmoscopy.

Importantly, she said, IOP may or may not be elevated in uveitis.

"With uncontrolled inflammation and decreased aqueous production, IOP tends to be low," Dr. Freedman said. "The initial treatment is usually topical ster oid. When the inflammation comes under better control, the eye will produce more aqueous and IOP will increase."

Elevation of IOP with topical ster oid treatment may be a so-called "ster oid response" or actual uveitic glaucoma. In children, a study by Ohji and colleagues found that nine of 11 children with normal eyes had a response to ster oids with IOP elevation. A later study by Fan et al. found that the IOP increased in many children even with a mild ster oid. Finally, Lam et al. conducted a large randomized trial of dexamethasone administered twice or four times daily and showed that 33% of children had IOP elevated 15 to 30 mm Hg above baseline, and 36% had an IOP more than 30 mm Hg and required timolol treatment. The peak IOP was 50 mm Hg in the group receiving treatment four times daily, and 41 mm Hg in the twice-daily group. IOP in these normal eyes returned to normal when the ster oids were stopped.