treatment plan

Differentiating the Red Eye (Part I): When it's Not Episcleritis

BY BRUCE E. ONOFREY, RPH, OD
SEPTEMBER 1999

If you say the words "sectoral injection" to a group of eyecare practitioners, you'll invariably hear the response, "episcleritis." But before you begin to manage this common condition, make sure you know how to differentiate episcleritis from scleritis.

Scleritis is an uncommon disease, only representing 0.08 percent of eye clinic referrals. It affects women more frequently than men (with a ratio of 8:5), and occurs in individuals over the age of 40. Unilateral cases are more common than bilateral ones, and 50 percent of the time, it's associated with underlying systemic disorders (Table 1).

Circulating antibody complexes lodge in the basement membrane of scleral vessels and initiate a local vasculitis. This may trigger the migration of macrophages and T-cells, which produce a granulomatous inflammatory response. Local tissue damage and ischemia can be profound. Early diagnosis and treatment is critical to decrease the risk of vision loss, perforation of the globe and loss of the eye.

Important Differences

Unlike episcleritis, scleritis generally causes significant pain, which can be localized or diffuse and is characterized as a dull ache that gradually increases over time. Unlike the bright redness seen in episcleritis, in scleritis, the eye exhibits a bluish-red color. When topically anesthetized, the area of the eye will exhibit pain when probed with a sterile cotton swab.

The Four Forms of Scleritis

1 Diffuse anterior scleritis represents 80 percent of all scleritis cases. In this form, there is dilation and tortuosity of the deep scleral vessels.

2 Nodular scleritis, the second most common form, produces one or more raised nodules with scleral thinning.

3 Necrotizing scleritis without inflammation is deceiving because perforation rarely occurs. Thinning, however, does occur, which makes visualization of the underlying choroid possible.

Necrotizing scleritis with inflammation is the most destructive form and can lead to the most serious consequences.

4 Posterior scleritis, the rarest type, is difficult to diagnose and can result in a fundus mass, annular choroidal detachments, exudative retinal detachment and cystoid macular edema.

Treatment in the non-necrotizing forms may involve topical steroids in non-necrotizing disease and oral anti-inflammatory agents. Immunosuppressive therapy may also be necessary.

It's critical that any underlying systemic disease be detected and managed by an internist or rheumatologist.

Dr. Onofrey, editor and author of ophthalmic texts, practices in Albuquerque, New Mexico.