Scleritis in Emergency Medicine

Updated: Feb 24, 2024
  • Author: Theodore J Gaeta, DO, MPH, FACEP; Chief Editor: Barry E Brenner, MD, PhD, FACEP  more...
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Overview

Practice Essentials

Scleritis is an inflammatory disease that affects the sclera; it may be localized, nodular, or diffuse. [1]  It may involve the anterior (visible segment) and/or posterior segments of the eye and manifest with redness of the eye and severe eye pain [2, 3]  Patients with isolated posterior scleritis will not present with redness of the visible portion of the eye and may or may not present with pain.

The 4 types of anterior scleritis are as follows:

  1. Diffuse anterior scleritis: This is characterized by widespread inflammation of the anterior portion of the sclera. It is the most common form of anterior scleritis as well as the most benign.

  2. Nodular anterior scleritis: This type is characterized by one or more erythematous, immovable, tender inflamed nodules on the anterior sclera. Approximately 20% of cases progress to necrotizing scleritis.

  3. Necrotizing anterior scleritis with inflammation: This form frequently accompanies serious systemic collagen vascular disorders including rheumatoid arthritis. [4]  Pain with this condition is usually extreme, and damage to the sclera is often marked. Necrotizing anterior scleritis with corneal inflammation is also known as sclerokeratitis.

  4. Necrotizing anterior scleritis without inflammation: This type most frequently occurs in patients with long-standing rheumatoid arthritis; it is due to the formation of a rheumatoid nodule in the sclera and is notable for its absence of symptoms. Necrotizing anterior scleritis without inflammation is also known as scleromalacia perforans.

Necrotizing anterior scleritis is the most severe form and most common form of scleritis with vision-threatening complications and resultant permanent visual loss. [5]  In cases of non-necrotizing scleritis, vision is often maintained unless complications such as uveitis occur. [6]

Posterior scleritis occurs much less frequently than anterior scleritis, but the two disorders may occur concurrently. [7] Posterior scleritis has been reported to mimic orbital cellulitis. [8] It is characterized by flattening of the posterior aspect of the globe, thickening of the posterior coats of the eye (choroid and sclera), and retrobulbar edema. [9]

The correct and rapid diagnosis and the appropriate systemic therapy can halt the relentless progression of both ocular and systemic processes, thus preventing destruction of the globe while prolonging survival and improving quality of life. See Treatment and Medication.

For patient education information, see Eye Pain.

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Pathophysiology

Proposed mechanisms for noninfectious scleritis include a variety of immune system effects, both cell-mediated and humoral, antibody mediated. Antigenic stimuli probably occur, and matrix metalloproteinases appear to be involved in the destruction of scleral tissue. [10]

The sclera, which consists of collagen and elastic connective tissue, provides a tough protective casing around the eye. Enzymatic degradation of collagen fibrils and invasion of inflammatory cells, including T cells and macrophages, appear to play an important role.

The thickness of the sclera varies from 0.3-1.2 mm. Healthy sclera is consistently white. Inflammation, the principal pathology affecting the sclera, is frequently part of a general inflammatory reaction associated with a systemic immune-mediated collagen vascular disease. [11, 12, 13]

Inflammation of the sclera can progress to ischemia and necrosis, eventually leading to scleral thinning and perforation of the globe. Necrotizing anterior scleritis represents a particularly destructive form of scleritis.

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Etiology

Scleritis coexists with a serious systemic disease in almost one half of cases; the underlying problem is frequently a connective tissue disorder. [12] Rheumatoid arthritis (RA) is the underlying disease for approximately one sixth of patients suffering from scleritis, and approximately 1% of patients with RA will develop scleritis at some point in the course of the disease. Scleritis associated with RA is due to the development of a rheumatoid nodule on the sclera and is associated with an increased risk of mortality. [12]

Scleritis also affects approximately 1% of patients with inflammatory bowel disease and is more likely to occur during disease remission. Individuals with Crohn's disease have a higher risk of developing scleritis and experiencing a recurrence than those with ulcerative colitis. [14]   

Other connective tissue and autoimmune diseases seen with scleritis include the following: [12]

  • Systemic lupus erythematosus (SLE)
  • Polyarteritis nodosa
  • Seronegative spondyloarthropathies - Ankylosing spondylitis, psoriatic arthritis, reactive arthritis
  • Granulomatosis with polyangiitis (Wegener granulomatosis)
  • Relapsing polychondritis [15]
  • Sarcoidosis
  • Inflammatory bowel disease [14]
  • Sjögren syndrome
  • IgG4-related disease [16]

Additional causes of scleritis include the following:

  • Syphilis [17]
  • Post–herpes zoster ophthalmicus
  • Poststreptococcal syndrome [18]
  • Tuberculosis
  • Gout
  • Lyme disease
  • Foreign body
  • Hypertension

Surgically-induced scleritis is a rare complication following ophthalmologic procedures such as the following:

  • Cataract surgery
  • Pterygium excision
  • Strabismus surgery
  • Retinal detachment repair [19]
  • Intravitreal injection [20]

A case of surgically-induced necrotizing scleritis following pars plana vitrectomy and intraocular lens replacement has been reported. [21]

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Epidemiology

Scleritis is an uncommon disease. Well-defined incidence rates are hard to find. An epidemiologic study of northern California data concluded that the overall incidence of scleritis was 3.4 per 100,000 person-years and the annual prevalence was 5.2 per 100,000 persons. [22] A population-based study from Olmsted County, Minnesota found that the annual incidence rate of scleritis was 5.54 per 100,000. The mean age at diagnosis was 48.8 years. [23]

Of patients diagnosed with scleritis, anterior scleritis is demonstrated in 94% of patients, as opposed to posterior scleritis, which is diagnosed only 6% of the time. An increased incidence of scleritis has been reported in patients taking bisphosphonates, which are commonly used in the management of osteoporosis. [19]

As scleritis is associated with systemic autoimmune diseases, it is more common in women, however, men are more likely to have infectious scleritis than women. [24]  Cases have been reported in patients ranging from 11-87 years of age but it usually occurs in the fourth to sixth decades of life. Mean age for all types of scleritis is 52 years.

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Prognosis

Necrotizing scleritis, the most destructive type of scleritis, and scleritis with extensive scleral thinning or perforation convey less favorable prognoses than other types of scleritis. Prognosis of scleritis, when originating from systemic disorders, usually conforms to the course of the underlying disease. Vergouwen et al reported the presence of anti-citrullinated peptide antibodies (ACPA) in non-infectious scleritis was associated with the development of necrosis. [25]

Morbidity arises from primary scleritis and associated systemic disease. In 15% of cases, scleritis is the presenting manifestation of collagen vascular disorder and may precede additional symptoms by one to several months. A significant percentage of patients with concurrent scleritis and collagen vascular disease die within 5 years.

One study demonstrated that spectral domain optical coherence tomography may be useful in following up on patient response to treatment. [26]

Scleral thinning leading to global perforation is the most devastating complication. Giant pigment epithelial tear and retinal detachment has been reported in a patient with scleritis. [27]  

Visual impairment is a possible complication. The cornea is affected more than 50% of time. Damage to the cornea may include uveitis, keratitis, glaucoma, and cataracts. [28]  Posterior chamber derangements may include the following:

  • Optic neuritis
  • Choroidal detachment
  • Macular edema
  • Retinal hemorrhage and/or detachment
  • Papilledema
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