Scleromalacia Perforans: Types and Complications

Scleromalacia perforans is a rare yet serious form of scleritis, an inflammatory disease that affects the white outer coating of the eye, called the sclera. Also known as necrotizing scleritis without inflammation, scleromalacia perforans is generally asymptomatic (without symptoms), but may cause painless eye irritation and redness. Over time, however, scleromalacia perforans can cause the inner eye pressure to increase abnormally, leading to visual disturbances and, on very rare occasions, the spontaneous rupture of the eye.

Scleromalacia perforans is most commonly seen in older people with long-standing autoimmune diseases, such as rheumatoid arthritis. If spotted early, scleromalacia perforans can be treated with immunosuppressants and anti-inflammatory drugs, although the response to treatment is variable at best.

Symptoms

In most people, scleromalacia perforans is entirely asymptomatic and is only recognized by the development of yellowish or graying patches or nodules on the sclera (typically in both eyes). People with the disease often complain of eye redness, dryness, and irritation but otherwise experience no loss of vision.

As the disease progresses, however, the nodules can cause underlying tissues to die, a condition referred to as scleral necrosis. In time, the sclera tissues will begin to separate and shed, leaving the underlying vascular layer of the eye (called the uveal tissue) exposed.

When this occurs, scleromalacia perforans can manifest with a cascade of eye problems, including:

• Astigmatism (changes in the eye shape)
• Staphyloma (bulging at the weak point in the eyeball)
• Anterior uveitis (inflammation of the middle layer of the eye, called the uvea)
• Cataract (clouding of the eye)
• Glaucoma (increased inner eye pressure)

Some of these complications, such as cataracts and glaucoma, occur as a result of long-term corticosteroid use in people with autoimmune diseases.

On extremely rare occasions, the thinning of the eye layers can cause the spontaneous rupture of the eyeball, referred to as global perforation. Although this is most commonly seen in people with severe glaucoma, it can also very rarely occur with only minor trauma due to the vulnerability of the thinning eye tissues.

If not treated appropriately, global perforation in people with scleromalacia perforans may not only result in blindness but a loss of the eye itself.

Causes

Scleromalacia perforans is most commonly seen in older women with long-standing rheumatoid arthritis (an autoimmune form of arthritis). Other autoimmune conditions closely linked to the disease include ankylosing spondylitis, lupus, gout, and granulomatosis with polyangiitis.

The cause of scleromalacia is still unknown, but is hypothesized to be the result of the gradual accumulation of immune complexes in the eye. Immune complexes are abnormal clusters of molecules caused by the binding of autoimmune antibodies to antigens in tissues (in this case, scleral tissues).

The buildup of immune complexes can cause structural changes to the sclera as well as the gradual obstruction of tiny blood vessels in the underlying choroid. It is the permanent obstruction of these vessels that causes tissue death.

Although scleromalacia perforans is largely considered to be an older person's disease, the slow progression of the disorder paired with the lack of notable symptoms suggests that it may start well before the age of 50.

Less commonly, scleromalacia perforans is linked to infections and conditions that directly damage the sclera, including herpes zoster ophthalmicus, ocular syphilis, and graft-versus-host disease (GvHD).

Diagnosis

Scleromalacia perforans is most commonly spotted by a family member, when looking at oneself in the mirror, or during a routine eye examination. The yellowish or grayish patches can sometimes give way to a bluish-black bulge as the sloughing (shedding) of scleral tissues reveals the underlying choroidal layer.

Scleromalacia perforans can be diagnosed by an ophthalmologist with the combination of a physical examination of the eye and a slit lamp (a microscope that visualizes the interior of the eye with a high-intensity light beam). The slit lamp will generally reveal a reduction in the number and size of blood vessels at the back of the eye, giving the tissues an almost porcelain-white appearance.

Lab Tests

If the cause is uncertain, blood tests may be performed to rule out other possible causes. These include a white blood cell count, C-reactive protein testing, and erythrocyte sedimentation rate (ESR). Elevated levels of any of these suggest that an infection or inflammatory process is involved, neither of which are inherently associated with scleromalacia perforans.

On the other hand, if a person with symptoms of scleromalacia perforans has no history of autoimmune disease, a serum autoantibody screen should be performed to determine if an undiagnosed autoimmune disorder is involved.

There are no blood tests that can diagnose scleromalacia perforans.

Imaging Studies

On occasion, a computed tomography (CT) scan may be ordered if an eye exam does not provide enough evidence of the disease. The scan will usually reveal areas of calcification (calcium deposits) where scleral tissues have been shed and thinned.

Fluorescein angiography, a technique used to map blood vessels with an injected fluorescent dye, can help determine if there is permanent vascular obstruction or if the condition is only temporary.

Treatment

The treatment of scleromalacia perforans can be challenging, particularly since it is usually only diagnosed when the disease is advanced and irreparable injury to the eyes has already occurred. Even so, certain treatments may slow or stop the progression of the disease.

Treatments and procedures commonly used include the following.

• Nonsteroidal anti-inflammatory drugs (NSAIDs): Although scleromalacia perforans is non-inflammatory, many of the causes and complications of the disease are inflammatory. NSAIDs like Advil (ibuprofen), Ocufen (flurbiprofen), and Tivorbex (indomethacin) are among the drug options commonly used.
• Immunomodulators: Because scleromalacia perforans is largely driven by autoimmunity, immunomodulators can be used to tamp down the autoimmune response and prevent disease progression. Options include Cytoxan (cyclophosphamide), methotrexate, Imuran (azathioprine), and CellCept (mycophenolate mofetil) as well as biologic drugs such as Enbrel (etanercept), Remicade (infliximab), Rituxan (rituximab), and Kineret (anakinra).
• Topical agents: Scleromalacia perforans is characterized by eye dryness, redness, and irritation and generally benefits from lubricating eye drops. Some doctors will prescribe sodium versenate eye drops to prevent the deterioration of collagen in the sclera and slow shedding (although the actual benefits of treatment remain unknown). The same applies to topical cyclosporin A.
• Scleral graft surgery: In the rare instance where global perforation occurs, surgery may be performed to patch the ruptured area with scleral tissues from a transplant donor. The benefits of the surgery need to be weighed against possible consequences given the increased risk of further necrosis and thinning.

Prognosis

As with the treatment of scleromalacia perforans, the prognosis of the disease can vary enormously, informed by everything from a person's age and general health to the multitude of risk factors that influence astigmatism, cataracts, glaucoma, and other eye conditions. Most people with later-stage complications will experience a gradual reduction in vision due to astigmatism.

Arguably, the greater concern is the underlying autoimmune disorder driving the disease. Oftentimes, the progression of scleromalacia perforans is a signal that the underlying disease is also progressing.

One such example is rheumatoid arthritis, in which the accumulation of immune complexes throughout the body can lead to rheumatoid vasculitis (the inflammation and narrowing of blood vessels). Symptomatic scleromalacia perforans often precedes rheumatoid vasculitis and can serve as a red flag for severe disease.

A Word From Verywell

Scleromalacia perforans is a rare but serious condition, particularly in older adults who are already at an increased risk of vision loss. As with most diseases, early detection of scleromalacia perforans is associated with better outcomes.

As such, you should never ignore the discoloration of the whites of the eyes or consider them a "normal part of aging." Have them checked out by an ophthalmologist (rather than an optician or optometrist) even if you don't have any risk factors for the disease, such as older age, female sex, or autoimmune disease.