Scleritis is a severe ocular inflammatory condition affecting the sclera, the outer covering of the eye. It can be categorized as anterior with diffuse, nodular, or necrotizing subtypes and posterior with diffuse or nodular subtypes. Scleritis can be visually significant, depending on the severity and presentation and any associated systemic conditions.[1] The presentation can be unilateral or bilateral.
Scleritis can be idiopathic or caused by infectious or noninfectious conditions. Additionally, associations with malignancy, autoimmune diseases, and surgically induced or medication side effects are causative factors. Viruses, bacteria, fungi, and parasites can cause infectious scleritis and are reported to occur in 4% to 10% of all cases.[2] Choroidal melanomas and conjunctival tumors can create ocular inflammation that can mimic the signs and symptoms of scleritis. 50% of patients with scleritis will have an autoimmune condition, sometimes undiagnosed at the time of presentation. Rheumatoid arthritis and systemic vasculitic conditions are most commonly associated with scleritis. [3]
Surgically induced scleritis has been associated with pterygium removal and scleral buckle procedures. Medications used to treat osteoporosis such as bisphosphonates have been found to cause scleritis; however, reports of this occurrence are rare.[2]
Limited, population-based studies have reported 10,500 cases of scleritis in the United States per year or an estimated four to six cases per 100,000 persons.[3]
It affects patients in middle age, commonly between 47 to 60 years.[2] Scleritis is more common in women, with a 60% to 74% predominance.[2] Limited information is known about incidence of children besides case reports.
The exact pathophysiology of scleritis is still under investigation. The anatomical structure of the sclera includes an extracellular matrix of collagen, elastin, and proteoglycans that closely resemble the components of joints, causing it to be susceptible to inflammatory conditions such as rheumatoid arthritis.[1] Additionally, the sclera is mostly avascular and requires transport of nutrients and removal of cellular wastes on the surrounding episcleral and choroidal vascular systems.
The disease's histopathological features are similar to those seen in vasculitic conditions. Scleral biopsies from patients with severe scleritis or necrotizing scleritis demonstrated vascular occlusions and infiltration, necrosis, and evidence of macrophages and T cells.[3]
The presentation can vary depending on the location and subtype of scleritis and can be unilateral or bilateral.[4] [5]
Anterior
Diffuse
Nodular
Necrotizing
Necrotizing Without inflammation (Scleromalacia perforans)
Posterior
The diagnosis is based on the clinical presentation and ocular exam with a detailed history and review of systems, targeted laboratory tests, and imaging studies.[2]
Common Lab Tests
Imaging
The treatment and management of scleritis are designed to determine any causative factor, manage ocular inflammation, control ocular pain and symptoms, prevent sequela, and reduce recurrences.[2][4] [5]
Anterior Infectious
Treatment tailored to infectious cause
Anterior Noninfectious
First line treatments
Second line treatments
Third line treatments
Fourth line treatments
Posterior
Requiring intense and immediate treatment
First line treatments
Second line treatments
- Prescribed when oral NSAID treatment fails
- Oral prednisone of 1 mg/kg/day; 60 to 80 mg per day
Third line treatments
Fourth line treatments
The main differential diagnosis of scleritis is episcleritis. Episcleritis is defined as inflammation of the superficial episcleral tissues and blood vessels. Patients can present with mild pain, redness, foreign body sensation, and tearing. Upon installation of 2.5% topical phenylephrine in the affected eye, the blood vessels will blanch with episcleritis but will not blanch with scleritis.[2] Episcleritis is usually idiopathic and resolves without treatment.
Visual prognosis is relatively good for patients with mild or moderate scleritis that respond well to the appropriate medical treatment and management of any underlying systemic condition.[6] Necrotizing and posterior scleritis cases pose a higher risk of visual loss to the extent of the inflammation and involvement of other ocular structures.
Sequela resulting from scleritis can vary depending on the severity of presentation and any associated autoimmune conditions and can include decreased vision, cataracts, increased intraocular pressure, scleral thinning or melting, and corneal thinning. [6]
it is important to discuss the risk of associated systemic conditions with patients with scleritis. Emphasis on proper pain management and control of inflammation is essential for visual recovery and improved prognosis.
At least half of scleritis cases can be linked to an autoimmune condition. Order specific laboratory tests and imaging according to patient demographics, detailed history, and physical examination. Investigation for an associated autoimmune condition must be completed at first presentation of scleritis if the patient is unaware of any systemic health problems. Instill one drop of 2.5% topical phenylephrine to observe any vessel blanching and to distinguish between episcleritis versus scleritis.[2]
Essential communication with internal medicine, eye care providers, and medical specialists (Rheumatology) is required for proper medical management and to improve patient outcomes.
[1] | Scleritis., Okhravi N,Odufuwa B,McCluskey P,Lightman S,, Survey of ophthalmology, 2005 Jul-Aug [PubMed PMID: 15967190] |
[2] | Daniel Diaz J,Sobol EK,Gritz DC, Treatment and management of scleral disorders. Survey of ophthalmology. 2016 Nov - Dec [PubMed PMID: 27318032] |
[3] | Artifoni M,Rothschild PR,Brézin A,Guillevin L,Puéchal X, Ocular inflammatory diseases associated with rheumatoid arthritis. Nature reviews. Rheumatology. 2014 Feb [PubMed PMID: 24323074] |
[4] | Sims J, Scleritis: presentations, disease associations and management. Postgraduate medical journal. 2012 Dec [PubMed PMID: 22977282] |
[5] | Oray M,Meese H,Foster CS, Diagnosis and management of non-infectious immune-mediated scleritis: current status and future prospects. Expert review of clinical immunology. 2016 Aug [PubMed PMID: 27055583] |
[6] | Wieringa WG,Wieringa JE,ten Dam-van Loon NH,Los LI, Visual outcome, treatment results, and prognostic factors in patients with scleritis. Ophthalmology. 2013 Feb [PubMed PMID: 23177360] |