San Francisco -- Understanding the cause of elevated IOP in patients with uveitis is the basis for developing a rational treatment plan, said Emmett Cunningham Jr., MD, PhD, MPH, at Glaucoma Symposium 2012.
Dr. Cunningham explained that there are four mechanisms underlying uveitic ocular hypertension/glaucoma: 1) inflammatory ocular hypertension syndrome (IOHS); 2) acute uveitic angle closure; 3) corticosteroid-induced; and 4) a mixed mechanism involving structural changes from chronic inflammation. Clinical clues, including recognition of the unique temporal relationship between the inflammation and IOP for each condition, helps guide the diagnosis.
In IOHS, IOP becomes elevated at the onset of inflammation and decreases as the inflammation resolves.
"Infection often underlies IOHS, and it's not clear whether the elevated IOP in these cases is the direct result of inflammation of the trabecular meshwork or infection-induced elevation of some intrinsic hypertensive factor(s), such as rho-kinases," noted Dr. Cunningham, director, uveitis service, California Pacific Medical Center, and adjunct clinical professor of ophthalmology, Stanford University School of Medicine.
Herpetic infection caused by herpes simplex virus (HSV), varicella zoster virus (VZV), or cytomegalovirus (CMV), is the prototypical cause of IOHS, and so it is important to look for signs of herpetic disease in patients who present with acute anterior uveitis. Clues include characteristic corneal findings and skin changes along with sector iris atrophy. Clinicians should also be aware of emerging reports, predominantly from Asia, of CMV infection as a cause of anterior uveitis in immunocompetent...