oPatientPlus articles are written by UK doctors and are based on research evidence, UK and European Guidelines. They are designed for health professionals to use, so you may find the language more technical than the condition leaflets.
Refers to the common and usually benign condition characterised by inflammation of the episclera, which lies between the conjunctiva and the sclera. It is usually an idiopathic condition but may occasionally occur in the context of underlying disease or exogenous inflammatory stimuli (see below).
The exact prevalence is unknown (as many patients probably do not present), but it occurs most frequently in younger patients: young adult to fifth decade and is thought by some to occur more often in women.
The most common form is simple episcleritis which is a recurring but self-limiting inflammation affecting part (simple sectoral episcleritis) or all (simple diffuse episcleritis) of the episclera, lasting 7-10 days before spontaneously resolving. If there are underlying systemic predisposing conditions, episodes may be more prolonged (eg two to three weeks). It often recurs at one- to three-month intervals.
Less commonly, nodular episcleritis occurs. This is more severe than simple episcleritis and takes longer to resolve. It is also much more likely to be associated with systemic disease (see 'Associated diseases', below).
Episcleritis does not progress to scleritis.
This refers to the generally much more severe inflammation that occurs throughout the entire thickness of the sclera.
This is rare, of the order of 0.1% of presentations in the emergency eye clinic, occurring very slightly more frequently in women and generally in an older age group than patients with episcleritis, with a mean age at presentation of 52 years.
It is classified according to which part of the sclera is affected. It may be anterior (90% of cases) or posterior (10% of cases) and there are four clearly recognisable groups of the anterior form:
- Diffuse anterior - this is the most common (and benign) form, characterised by widespread inflammation of the anterior sclera. It accounts for about 50% of scleritis cases. It is not usually sight-threatening and tends to resolve.
- Nodular - there are erythematous, tender, fixed nodules which, in 25% of cases, progress on to necrotising scleritis. It commonly recurs.
- Necrotising - this is less frequent (10% of cases) and is characterised by extreme pain and marked scleral damage; it is usually associated with underlying systemic disease. Where there is associated corneal inflammation, this is also known as sclerokeratitis.
- Scleromalacia perforans - (5% of cases) this is also known as necrotising anterior scleritis without inflammation and is notable for its lack of symptoms. It is bilateral and is only seen with advanced rheumatoid arthritis (usually in women).
About one third of patients with posterior scleritis have associated anterior scleritis. A grading system using photographs has recently been proposed but is not yet commonly used.
|Signs relating to presentation||
|Other ocular signs||
||The following may occur:
Episcleral vessels can be moved with a cotton bud. If you apply phenylephrine 10%, they blanch (remember that this will also dilate the pupil). Scleral vessels appear darker, follow a radial pattern, are immobile and do not blanch.
Posterior scleritis has a more extensive list of differential diagnoses including:
- Optic neuritis.
- Retinal detachment.
- Tumours of the choroid.
- Orbital inflammatory disease/mass.
- Uveal effusion syndrome.
- Harada's disease.
- Intraocular lymphoma.
A simple case of episcleritis need not be investigated once a thorough history is taken and examination is carried out to rule out the possibility of an associated systemic disease (see 'Associated diseases', below). If there is a suspicion, biochemical tests should be performed as guided by concern (eg antinuclear antibody, rheumatoid factor, serum uric acid levels, etc.). Patients who may benefit from investigation include those with nodular disease and individuals with severe recurrent episodes.
- This condition is most commonly idiopathic but 30% of cases are associated with underlying systemic disease.
- The most commonly associated systemic disorders are inflammatory bowel diseases: ulcerative colitis and Crohn's disease.
- Another common association is hyperuricemia, seen in about 11% of these patients.
- Connective tissue disease such as rheumatoid arthritis, polyarteritis nodosa, systemic lupus erythematosus and Wegener's granulomatosis have also been associated with recurring episcleritis.
- Infectious causes are less common but known, including herpes zoster virus, herpes simplex virus, Lyme disease, syphilis, hepatitis B and Brucellosis. More rarely, fungi and parasitic infestations may be associated with episcleritis.
- Miscellaneous associations include gout, rosacea, atopy, lymphoma and thyroid eye disease. A foreign body or chemicals may also cause episcleritis.
- There are some very rare but documented associations with a number of other conditions including T-cell leukaemia, paraproteinaemia, paraneoplastic syndromes, Wiskott-Aldrich syndrome, adrenal cortical insufficiency and progressive hemifacial atrophy. There has been a case report of episcleritis associated with menstruation.
- Treatment is not usually required.
- Artificial tears may provide some relief, particularly in nodular disease.
- The use of topical non-steroidal anti-inflammatory drugs (NSAIDs) such as ketorolac trometamol (Acular® 1 drop tds) can be helpful in more symptomatic individuals.
- Where the episode is more severe, a short course of topical steroids may be required (under ophthalmologist supervision) and nodular episcleritis may respond best to oral NSAIDs (eg Froben® 50 mg tds).
- It is important to review these patients (a week after initial presentation is adequate) to ensure resolution of symptoms.
- If the episode is severe, not resolving or if it recurs more than three times, it is appropriate to refer to the Eye Clinic.
Involvement of ocular structures is rare: there may occasionally be corneal involvement (in the form of inflammatory cell infiltrates or oedema) and recurrent attacks over a period of years may induce some degree of slight scleral thinning. Complications more commonly occur in those patients who have frequently and repeatedly had need to resort to topical steroid treatment over a number of years, and include cataract formation, ocular hypertension and steroid-induced glaucoma. There may also be rebound inflammation from steroid withdrawal.
This is a mild, self-limiting disease which tends to resolve fully over 1-2 weeks (5-6 weeks in nodular episcleritis) but patients should be aware that episodes may recur in the same or the fellow eye. The treatment-related complications are the commonest cause of visual impairment in these patients (hence the need to recognise the benign nature of this disease and not to overtreat).
Every effort should be made to rule out associated ocular or systemic pathology (see 'Associated diseases', below). Depending on clinical suspicion, biochemical tests (eg full blood count and inflammatory markers, rheumatoid screen, syphilis screen), urine dipstick for blood and protein, B-scan ultrasonography of the globe, plain X rays (chest and sacroiliac joints), MRI or CT imaging (sinuses and orbits) may be indicated.
The frequency of association and the severity of these associated problems means that it has to be assumed that there is an underlying cause until proven otherwise. In a patient with no previously diagnosed systemic disease, it is important to rule out systemic vasculitis as this is the least likely to have been previously diagnosed and it is a potentially life-threatening disorder.
Usually, these investigations will be carried out jointly between the ophthalmologists and other relevant hospital specialists, particularly the rheumatologists.
- At least 50% of these patients have an underlying systemic disease and, in 15% of cases, the scleritis is the first presentation of a collagen vascular disorder, preceding it by one to several months.
- Scleritis is frequently associated with connective-tissue diseases of which rheumatoid arthritis is by far the most common. Other connective-tissue diseases seen are Wegener's granulomatosis, relapsing polychondritis, systemic lupus erythematosus, Reiter's syndrome, polyarteritis nodosa and ankylosing spondylitis.
- Other common associations include gout, Churg-Strauss syndrome and syphilis.
- It may occur following ocular surgery. The aetiology is not exactly known but it tends to present as intense inflammation adjacent to the surgical site, usually within six months of the procedure. There is an association with the presence of underlying disease.
- Less common associations include tuberculosis and local infections (usually spreading from a corneal ulcer) - common culprits are Pseudomonas aeruginosa, Streptococcus pneumoniae, Staphylococcus aureus and varicella-zoster virus. It may also occur with Lyme disease. Fungal scleritis is very rare but should be suspected when the scleritis is not responding to immunosuppressive therapy (see 'Management', below).
- More unusual causes include sarcoidosis, hypertension, parasitic infestation, lymphoma and trauma or the presence of a foreign body. It has also been reported in patients taking bisphosphonates although the causality has been recently questioned.
If you suspect scleritis, make an immediate referral to the ophthalmologists.
- Management will depend on the type of scleritis and on whether there is any underlying systemic disease. These patients should all be under specialist care (usually co-managed by the ophthalmologists and rheumatologists).
- Generally, non-necrotising anterior scleritis will be treated with a progressive combination of oral NSAIDs (eg ibuprofen 400 mg qds) then oral prednisolone (eg 80 mg od) or a subconjunctival steroid injection such as triamcinolone acetonide (although this is contra-indicated in necrotising scleritis and, some say, should be contra-indicated in scleritis altogether) ± immunosuppressive therapy such as methotrexate. It may take several weeks to adjust the treatment to produce a satisfactory result.
- Surgery may be carried out for a diagnostic biopsy and can be required to address complications such as cataract formation and intractable glaucoma.
- Necrotising anterior scleritis is managed with systemic steroids and immunosuppressive therapies and may need surgical intervention if perforation is impending. Rituximab has been tried with success but only in a very small number of patients to date.
- Treatment has very limited effect in scleromalacia perforans but abundant lubrication may also be added to the regimen.
- Management of posterior scleritis is a little more controversial: young patients usually respond well to oral NSAIDs but elderly patients with associated disease or patients in whom there is a threat to vision are managed as with anterior non-necrotising scleritis.
- There are emerging treatment modalities such as infliximab but these remain the remit of sub-specialist and research centres.
- All patients with scleritis should have any underlying disease addressed urgently.
- Scleral thinning.
- Ischaemia of the anterior segment of the globe.
- Raised intraocular pressure.
- Retinal detachment.
- Phthisis (globe atrophy).
Generally, when scleritis originates from a systemic disorder, its course follows that of the underlying problem. However, anterior necrotising scleritis with inflammation is the most severe and distressing form of the disease. Most patients have an associated vascular disease. Where there is non-necrotising scleritis, the visual prognosis is usually reasonable providing that there are no ocular complications (eg uveitis). Otherwise, visual prognosis is poor. There is a mortality rate, related to the underlying condition, of ~ 25% within five years of the onset of scleritis. Posterior scleritis, in patients aged over 50, is associated with an increased risk of harbouring systemic disease and suffering visual loss.
There are no clear-cut preventative measures other than the rigorous control of the progression of any underlying disease and early treatment of the scleritis to minimise the risk of visual loss.
Further reading & references
- Roy Sr H, Episcleritis, Medscape, Oct 2010
- Denniston AKO, Murray PI; Oxford Handbook of Ophthalmology (OUP), 2009
- Gaeta TJ et al, Scleritis in Emergency Medicine, Medscape, Apr 2008
- Jackson TL; Moorfields Manual of Ophthalmology, Mosby (2008)
- Sen HN, Sangave AA, Goldstein DA, et al; A standardized grading system for scleritis. Ophthalmology. 2011 Apr;118(4):768-71. Epub 2010 Nov 20.
- The Wills Eye Manual (6th ed); 2012
- Kanski J. Clinical Ophthalmology, A Systematic Approach, 5th ed. Butterworth Heinemann (2003)
- Gungor K, Bekir NA, Namiduru M; Recurrent episcleritis associated with brucellosis. Acta Ophthalmol Scand. 2001 Feb;79(1):76-8.
- Thakker MM, Perez VL, Moulin A, et al; Multifocal nodular episcleritis and scleritis with undiagnosed Hodgkin's lymphoma. Ophthalmology. 2003 May;110(5):1057-60.
- Rajoo SG, Gandhewar J; Recurrent Episcleritis in Relation to Menstruation: A Case Report. Cornea. 2011 Mar 9.
- Williams CP, Browning AC, Sleep TJ, et al; A randomised, double-blind trial of topical ketorolac vs artificial tears for the treatment of episcleritis. Eye. 2005 Jul;19(7):739-42.
- McCluskey P: Scleritis. Fundamentals of Ophthalmology Series, BMJ books, 2001.
- Akpek EK, Thorne JE, Qazi FA, et al; Evaluation of patients with scleritis for systemic disease. Ophthalmology. 2004 Mar;111(3):501-6.
- Rich RM, Smiddy WE, Davis JL; Infectious scleritis after retinal surgery. Am J Ophthalmol. 2008 Apr;145(4):695-9. Epub 2008 Feb 1.
- Sawant SD, Biswas J; Fungal scleritis with exudative retinal detachment. Ocul Immunol Inflamm. 2010 Dec;18(6):457-8. Epub 2010 Sep 16.
- Ramirez-Ortiz MA, Vasquez-Resendis A; Isolated bilateral posterior scleritis after eye trauma. J AAPOS. 2007 Jun;11(3):284-5. Epub 2007 Jan 25.
- French DD, Margo CE; Postmarketing surveillance rates of uveitis and scleritis with bisphosphonates among a national veteran cohort. Retina. 2008 Jun;28(6):889-93.
- Onal S, Kazokoglu H, Koc A, et al; Rituximab for remission induction in a patient with relapsing necrotizing scleritis associated with limited Wegener's granulomatosis. Ocul Immunol Inflamm. 2008 Sep-Oct;16(5):230-2.
- Sassa Y, Kawano YI, Yamana T, et al; A change in treatment from etanercept to infliximab was effective to control Acta Ophthalmol. 2011 Apr 6. doi: 10.1111/j.1755-3768.2010.02090.x.
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Dr Olivia Scott
Dr Olivia Scott