Rheumatoid Arthritis
Rheumatoid arthritis (RA) is a chronic autoimmune disorder that causes the immune system to attack the body's tissues. It primarily affects the small joints such as hands and feet, causing swelling, bone erosion and joint deformity. It can, however, affect the entire body, including various structures of the eyes. Inflammation and immune system dysfunction can cause certain eye glands to stop functioning correctly, leading to a range of issues related to tear production, eye pressure and infection. In some cases, this can lead to secondary complications such as glaucoma and cataracts.
How RA Causes Dry Eyes
Rheumatoid arthritis commonly leads to dry eyes. The eye has two sets of structures that produce tears and a set of glands that help maintain moisture on the surface of the eye. Rheumatoid arthritis can cause swelling of these structures, leading to a decrease in the production of tears. Inflammation of the oil glands on the edge of the eyelid can also cause the normal tear film covering the eye to break down.
Sjogren's syndrome is an autoimmune disorder that occurs in approximately 10 to 15 percent of patients with rheumatoid arthritis. An accumulation of excess white blood cells occurs in the lacrimal glands (structures that produce tears in the eyes) and salivary glands, causing impaired secretion of tears and saliva. This dryness of the mucous membranes is called sicca complex, and dry eyes are known as keratoconjunctivitis sicca.
How RA Causes Inflammation of the Eyes
Rheumatoid arthritis can lead to a few different conditions characterized by inflammation of the eye. These conditions commonly occur among those with autoimmune disorders like rheumatoid arthritis, possibly because immune system dysfunction leads the body to attack tissues in various parts of the eye. One such condition, called uveitis, is a swelling of certain interior structures of the eye, including the iris, choroid (a layer of blood vessels lining the eye) and ciliary body (a thick ring of tissue that controls the shape of the eye's lens). Another condition called scleritis is an inflammation of the white part of the eye characterized by extreme pain and a purplish discoloration. A related condition known as episcleritis is an inflammation of the membrane covering the white part of the eye, causing redness and discomfort.
How RA Causes Vision Loss
The effects of sustained inflammation of the structures of the eye brought on by rheumatoid arthritis can lead to complications that include vision loss, cataracts or glaucoma. Glaucoma--a serious condition that can cause blindness due to damage to the optic nerve--can develop in response to poor drainage of fluids from the eye. Inflammation of eye tissues and glands can interfere with the balance of tear production and drainage, leading to high intraocular pressure. Elevated eye pressure levels can cause glaucoma and related symptoms such as blurred vision, eye pain and partial or total vision loss.
Cataracts (a clouding of the lens of the eye) may also develop as a result of long-term inflammation of the eye. The fibers on the normally clear lens of the eye may start to clump together in response to inflammation and autoimmune dysfunction, causing the lens to become "dirty" and vision to become blurred or dimmed.
