Amyloidosis is a rare condition characterized by the accumulation of abnormal protein deposits, called amyloid fibrils, within various organs and tissues throughout the body. This buildup can impair the normal function of affected organs. The eyes are among the areas where these protein deposits can form, leading to ocular symptoms and vision problems. Ocular amyloidosis can manifest as a localized issue confined to the eyes or as part of a broader systemic disease affecting multiple organs.
Recognizing Eye Symptoms
Eye symptoms of amyloidosis vary depending on where amyloid proteins accumulate. People may experience blurry vision, ranging from mild to severe. Dry eyes and irritation are common, sometimes feeling like a foreign body. Double vision (diplopia) can occur, along with impaired eye movement.
Light sensitivity (photophobia) is another symptom. Visible deposits may appear in the eyelids or on the conjunctiva (the membrane lining the inside of the eyelids and covering the white part of the eye). These deposits can appear as waxy, yellowish masses or small lumps. Drooping of the upper eyelid (ptosis) is a common symptom, and purplish patches around the eyes may also be noticed, especially after rubbing. Glaucoma, which can damage the optic nerve and lead to vision loss, is also linked to ocular amyloidosis.
How Amyloid Deposits Affect Vision
Amyloid proteins can accumulate in nearly any part of the eye, disrupting its normal function. When deposits form in the vitreous humor, the clear, gel-like substance in the center of the eye, they can cause cloudiness. This cloudiness, often described as cobwebs, sheets, or pearls in vision, obstructs light to the retina, causing blurred or distorted vision. In the retina, the light-sensitive membrane at the back of the eye, amyloid proteins can alter how the eye detects light, leading to discolorations or distortions.
Accumulation in the optic nerve can impair nerve signals from the eye to the brain. In the eyelids and extraocular muscles, which control eye movement, amyloid deposits can lead to lumps, swelling, drooping eyelids, and double vision by restricting muscle function. When amyloid accumulates in the cornea, the clear outer layer of the eye, it can cause haziness or form patterns like branching white lines, affecting light entry and vision clarity. If deposits collect in the trabecular meshwork, the eye’s drainage canals, they can block the outflow of fluid, increasing intraocular pressure and potentially leading to glaucoma.
Diagnosing Ocular Amyloidosis
Diagnosing ocular amyloidosis involves a thorough eye examination to identify any signs or impairments. A slit-lamp examination allows an eye care professional to view the front eye structures, such as the cornea, iris, and lens, in magnified detail. Ophthalmoscopy, examining the back of the eye, assesses the retina and optic nerve for any abnormalities. Specialized imaging techniques, such as optical coherence tomography (OCT) or ultrasound, provide more detailed views of internal eye structures and help detect amyloid deposits.
To confirm amyloid deposits, a tissue biopsy is often necessary. This might involve a conjunctival biopsy (a small sample from the conjunctiva) or a fat pad biopsy, which can help detect systemic amyloidosis. The collected tissue is then examined under a microscope for amyloid features. Since ocular amyloidosis can be localized or part of a systemic disease, a comprehensive systemic evaluation is usually performed to determine the type of amyloidosis and assess if other organs are affected. This evaluation helps guide management and treatment strategies.
Managing Eye-Related Amyloidosis
Managing eye symptoms caused by amyloidosis involves symptomatic treatments and more definitive interventions. For symptoms like dry eyes, artificial tears or lubricating gels can provide relief. If glaucoma develops due to amyloid deposits, eye drops may be prescribed to lower intraocular pressure.
For significant visual impairment from amyloid accumulation in the vitreous humor, pars plana vitrectomy (PPV) is frequently performed. This surgery removes the cloudy, amyloid-filled vitreous gel, clearing the light path to the retina and improving vision. While effective, new deposits can form over time, sometimes requiring repeat procedures. Treatment decisions are influenced by whether ocular amyloidosis is localized or part of a systemic condition. When systemic amyloidosis is present, managing the underlying systemic disease, often with collaboration among specialists, can also help address eye symptoms.