What Is Rheumatoid Arthritis?
Rheumatoid arthritis (RA) is a chronic autoimmune inflammatory condition of the joints. It is characterized by damage to the cartilaginous part and erosion of the bony part of the joint. Apart from the joints, it also affects the heart, kidneys, and blood vessels.
What Is the Cause of Rheumatoid Arthritis?
Rheumatoid arthritis is considered an autoimmune disease in which the body's defense cells start acting against one's body itself.
What Is the Mechanism in the Formation of Rheumatoid Arthritis?
The exact mechanism involved in the development of rheumatoid arthritis is not known. Though, transformation of the body's immune cells against its own cells is the most accepted theory.
Can Rheumatoid Arthritis Affect Eyes?
Rheumatoid arthritis can also affect the eyes. The ocular manifestations of the disease are often the primary clinical presentations and appear before any other signs and symptoms.
What Are the Different Ocular Diseases Associated With Rheumatoid Arthritis?
Any part of the eye may be involved in the case of rheumatoid arthritis, the most common being the anterior segment of the eye.
The most common eye lesions associated with RA are:
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Keratoconjunctivitis sicca. It is the dryness of the loose tissue covering the eyeball (conjunctiva) and the outermost transparent layer of the eye (cornea).
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Inflammation of the episcleral tissue is present between the conjunctiva and white part of the eye (sclera), also known as episcleritis.
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Inflammation of the sclera (scleritis).
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A peripheral ulcerative keratitis is a group of inflammatory conditions characterized ultimately by corneal thinning.
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Inflammation of the middle layer of the eye consisting of the uvea and the pigmented part of the eye (iris) is called anterior uveitis.
What Is the Mechanism Involved Behind the Various Ocular Manifestations of RA?
The basal mechanism involved is the autoimmune action of the body’s defense cells.
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In the case of keratoconjunctivitis sicca, the immune cells destroy the epithelium of the lacrimal gland by oxidative stress. This results in a decrease in the production of tears.
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Episcleritis and scleritis are caused by the chronic granulomatous inflammation of the blood vessels supplying the episclera and sclera, leading to the activation of the immune cells against the tissue and its destruction.
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Infiltration and deposition of the immune complex in the periphery of the corneal blood vessels result in the perforation of the cornea and ultimately cause blindness.
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The anterior segment of the eye is already rich with immune cells, which suppress the immune reaction. In RA, the suppression mechanism is disturbed, which leads to inflammation and anterior uveitis.
What Are the Clinical Signs and Symptoms of Various Ocular Diseases of RA?
The ocular diseases in RA present with the following signs and symptoms:
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The most common feature of patients suffering from keratoconjunctivitis sicca is dry eyes, along with grittiness of the eyes and a burning sensation.
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Episcleritis is more prevalent in females, especially in the age group of forty-five to sixty-four. The disease, when present with RA, shows bilateral eye involvement. Patients with episcleritis present with tearing, redness of the eye, and mild pain.
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Scleritis is also twice more common in females. Nodular and diffuse forms are most commonly detected. It is characterized by the presence of red eyes with severe pain, which is stabbing in character.
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Peripheral ulcerative keratitis is associated with systemic inflammation of the blood vessels. It is rarer than other diseases and shows a male predominance, especially in males with a previous history of ocular surgery. Patients suffer from severe pain along with tearing and blurry vision.
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Anterior uveitis is a common ocular disease in patients with RA. It is clinically characterized by pain, decrease in vision, tearing, sensitivity to light, and redness with discharge.
How Are the Ocular Diseases of the RA Diagnosed?
The diagnosis of the various ocular disease associated with RA is mainly done by clinical examination of the eye along with history. Imaging and laboratory tests are used as an adjunct to help form a confirmatory diagnosis.
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There are no gold-standard diagnostic tests for diagnosing keratoconjunctivitis sicca. The amount of tears produced is measured by Schrimers test, and fluorescence staining. Questionnaires are also used to assess the quality of life in patients with the disease. Fluorescence staining helps in detecting the disease at an early stage.
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Episcleritis and scleritis are diagnosed clinically with the help of slit-lamp technique. Difference between episcleritis and scleritis is established by administering phenylepinephrine. The eye appears normal if the inflammation is limited to the episclera, this is because of the blanching of the vascular episclera.
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Slit-lamp techniques show thinning of the sclera and ulcerations of the cornea, while the ultrasound is used to investigate the thickening of episcleral tissues in case of scleritis.
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Clinical examination with slit-lamp technique for peripheral ulcerative keratitis shows the presence of a crescent-shaped corneal ulcer.
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Anterior uveitis is mainly diagnosed clinically.
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Apart from the above investigations, tests for rheumatoid factor, erythrocyte sedimentation rate, antinuclear antibodies, etc., are conducted to detect the underlying disease.
How Are the Ocular Diseases of RA Managed?
The various treatment modalities used for managing the ocular diseases linked to RA include:
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Keratoconjunctivitis sicca is treated symptomatically with the use of artificial tears, moisture chamber goggles, secretagogues, night ointments, and topical steroids. Since inflammation is the cause of ocular presentations, antiinflammatory drugs like Cyclosporine, corticosteroids, and anti-rheumatoid drugs are prescribed along with the conventional therapy.
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Episcleritis has a higher recurrence rate when it occurs with RA. Hence the underlying disease is controlled. Artificial tears are prescribed for symptomatic relief.
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Mild scleritis is treated with oral non-steroidal anti-inflammatory drugs, while severe cases require corticosteroids and immunosuppressive agents like Methotrexate, Cyclophosphamide, and Mofetil. Tumor necrosis factor inhibitors are used in long-standing cases.
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Peripheral ulcerative keratitis is best managed by the application of artificial tears, bandage contact lenses, and topical antibiotics. Biologics and immunosuppressive drugs help stabilize the disease and prevent further deterioration. Surgery in severe cases involves tissue adhesive contacts with corneal grafting.
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Anterior uveitis is treated with topical glucocorticoids. Immunosuppressive therapy and biologics are considered in the early phase of the disease for better results.
What Are the Complications Linked to the Ocular Diseases in RA?
The ocular diseases of RA, if left untreated can cause the following complications:
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Keratoconjunctivitis sicca leads to opacification of the cornea, and in severe cases, results in vision loss.
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Episcleritis and scleritis can result in cataracts, glaucoma, and ocular hypertension. Scleral thinning and retinal swelling can also occur in scleritis.
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Peripheral ulcerative keratitis causes corneal scarring, perforations, thinning, and vision loss.
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Anterior results in retinal swelling, damage to the optic nerve, retinal detachment, and permanent blindness.
What Is the Prognosis of the Eye Lesions Associated With RA?
Eye lesions of RA are immune-modulated inflammatory conditions that can only be stabilized and inhibited from further deterioration with the use of antiinflammatory and immunosuppressive drugs. Complete remission of the condition is not easy.
Conclusion
RA presents itself with extra-articular signs, including ocular signs. The eye lesions are often a precedent of an underlying systemic disease. Rheumatologists and ophthalmologists should be aware of the ocular presentations of RA to manage the lesions at an early stage and avoid complications.
