History

Fact Explanation
Eye pain. Due to inflammation of the scleral tissue resulting in stretching of its short posterior and long ciliary nerve supply [1].
Tearing and photophobia. It indicates the presence of a necrotizing process [2].
Decreased vision. Scleritis can lead to uveitis which is known to be associated with macular oedema [3].
Red eye. Due to scleral edema and dilatation of deep episcleral vessels [1].
History of joint pain and morning stiffness of joints. Scleritis is known to be associated with rheumatoid arthritis [4].
History of ocular surgery or trauma. The release of scleral tissue components after injury or surgical trauma may start an immunological reaction against scleral antigens resulting in scleral inflammation [5].
References
  1. GALOR ANAT, THORNE JENNIFER E.. Scleritis and Peripheral Ulcerative Keratitis. Rheumatic Disease Clinics of North America [online] 2007 November, 33(4):835-854 [viewed 09 July 2014] Available from: doi:10.1016/j.rdc.2007.08.002
  2. WATSON P. G., HAYREH S. S.. Scleritis and episcleritis.. British Journal of Ophthalmology [online] 1976 March, 60(3):163-191 [viewed 09 July 2014] Available from: doi:10.1136/bjo.60.3.163
  3. ROTHOVA A, SUTTORP-VAN SCHULTEN M S, FRITS TREFFERS W, KIJLSTRA A. Causes and frequency of blindness in patients with intraocular inflammatory disease.. British Journal of Ophthalmology [online] 1996 April, 80(4):332-336 [viewed 09 July 2014] Available from: doi:10.1136/bjo.80.4.332
  4. MCGAVIN DD, WILLIAMSON J, FORRESTER JV, FOULDS WS, BUCHANAN WW, DICK WC, LEE P, MACSWEEN RN, WHALEY K. Episcleritis and scleritis. A study of their clinical manifestations and association with rheumatoid arthritis. Br J Ophthalmol [online] 1976 Mar, 60(3):192-226 [viewed 09 July 2014] Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1042707
  5. RAMIREZ-ORTIZ MARCO A., VASQUEZ-RESENDIS ALEJANDRO. Isolated bilateral posterior scleritis after eye trauma. Journal of American Association for Pediatric Ophthalmology and Strabismus [online] 2007 June, 11(3):284-285 [viewed 09 July 2014] Available from: doi:10.1016/j.jaapos.2006.09.019

Examination

Fact Explanation
Deep bluish red or violaceous appearance of the sclera. Due to the inflamed scleral tissue associated with a congested scleral vascular plexus that is deep purple in color [1].
Apearance of a sclera with a greyish tinge to it. After recurrent attacks of scleral inflammation the sclera may become more transparent and is sometimes thinner, and as a consequence the grey choroid may be seen through the sclera [2].
Scleral edema and dilatation of scleral vessels, seen on slit lamp examination of the eye. It is used to distinguish scleritis from episcleritis. In episcleritis there will be no scleral edema [2]. It should be noted that on examination any corneal changes and evidence of uveitis could also be identified.
References
  1. LACHMANN SM, HAZLEMAN BL, WATSON PG. Scleritis and associated disease. Br Med J [online] 1978 Jan 14, 1(6105):88-90 [viewed 09 July 2014] Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1602644
  2. WATSON P. G., HAYREH S. S.. Scleritis and episcleritis.. British Journal of Ophthalmology [online] 1976 March, 60(3):163-191 [viewed 09 July 2014] Available from: doi:10.1136/bjo.60.3.163

Differential Diagnoses

Fact Explanation
Episcleritis. It also presents with red eye but pain is not a prominent feature and the sclera has a bright fiery redness to it [1].
Viral conjunctivitis. It also presents with red eye, but the patient will usually complain of irritation beginning in one eye and spreading to the other a few days later [2].
Anterior uveitis. It also presents with red eye and reduced vision, but photophobia is a common feature as well [3].
References
  1. LACHMANN SM, HAZLEMAN BL, WATSON PG. Scleritis and associated disease. Br Med J [online] 1978 Jan 14, 1(6105):88-90 [viewed 09 July 2014] Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1602644
  2. MAHMOOD AHMED R., NARANG ANEESH T.. Diagnosis and Management of the Acute Red Eye. Emergency Medicine Clinics of North America [online] 2008 February, 26(1):35-55 [viewed 09 July 2014] Available from: doi:10.1016/j.emc.2007.10.002
  3. SMITH JUSTINE R, HART PRUE H, WILLIAMS KERYN A. Basic pathogenic mechanisms operating in experimental models of acute anterior uveitis. Immunol Cell Biol [online] 1998 December, 76(6):497-512 [viewed 09 July 2014] Available from: doi:10.1046/j.1440-1711.1998.00783.x

Investigations - for Diagnosis

Fact Explanation
Ultrasonography/ CT/ MRI scan to detect flattening of the posterior aspect of the globe, thickening of the posterior coats of the eye (choroid and sclera), and retrobulbar edema. It occurs in posterior scleritis, misdiagnosis of which is very common and occurs due to its variable presentations. In addition, several inflammatory and non-inflammatory ocular diseases such as posterior uveitis, Vogt-Koyanagi-Harada syndrome, pseudotumor of the orbit, and central serous chorioretinopathy can closely mimic this condition, all of which can be identified with the various scans. Early diagnosis is important because prompt treatment often leads to complete resolution with excellent visual recovery [1].
References
  1. BISWAS J, MITTAL S, GANESH SK, SHETTY NS, GOPAL L. Posterior scleritis: clinical profile and imaging characteristics. Indian J Ophthalmol [online] 1998 Dec, 46(4):195-202 [viewed 09 July 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/10218301

Investigations - Screening/Staging

Fact Explanation
Rheumatoid factor levels in blood. Scleritis is commonly associated with rheumatoid arthritis [1].
Anti nuclear antibody levels in blood. Scleritis is associated with sysystemic lupus erythematosus [2].
Serum uric acid levels. Scleritis is commonly associated with gout [3].
Antineutrophil cytoplasmic antibodies in blood. Scleritis is commonly associated with Wegener’s granulomatosis [2].
Chest radiography. Scleritis is associated with Tuberculosis [3].
References
  1. MCGAVIN DD, WILLIAMSON J, FORRESTER JV, FOULDS WS, BUCHANAN WW, DICK WC, LEE P, MACSWEEN RN, WHALEY K. Episcleritis and scleritis. A study of their clinical manifestations and association with rheumatoid arthritis. Br J Ophthalmol [online] 1976 Mar, 60(3):192-226 [viewed 09 July 2014] Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1042707
  2. GALOR ANAT, THORNE JENNIFER E.. Scleritis and Peripheral Ulcerative Keratitis. Rheumatic Disease Clinics of North America [online] 2007 November, 33(4):835-854 [viewed 09 July 2014] Available from: doi:10.1016/j.rdc.2007.08.002
  3. WATSON P. G., HAYREH S. S.. Scleritis and episcleritis.. British Journal of Ophthalmology [online] 1976 March, 60(3):163-191 [viewed 09 July 2014] Available from: doi:10.1136/bjo.60.3.163

Management - Specific Treatments

Fact Explanation
Non steroidal anti-inflammatory drugs- first line. Eg: Ibuprofen Dose: 400-800 mg 6-8 hourly given orally. NSAIDs inhibit cyclooxygenase-2 enzyme, thereby inhibiting the production of prostaglandins which are involved in the inflammatory process [1] The initial therapy consists of such agent. In case of failure to respond to treatment, 2 different NSAIDs should be considered.
Corticosteroids. Prednisolone. Dose: 1 mg/kg/day (maximum of 60 mg/daily) followed by a tapering schedule. They are used when there is no response to NSAIDs. The most important action of corticosteroids is switching off multiple activated inflammatory genes. In addition, corticosteroids may activate several anti-inflammatory genes and increase the degradation of mRNA encoding certain inflammatory proteins [2].
Immunosuppressive drugs. Eg: Methotrexate Dose: 25 mg/week. These are used when the above treatment options fail and in the case of necrotizing scleritis. Low dose weekly therapy leads to intracellular accumulation of 5-aminoimidazole-4-carboxamide ribonucleotide, which promptes increased adenosine release at sites of inflammation. This increase in extracellular adenosine diminishes both the accumulation and function of leukocytes in inflamed sites [3].
References
  1. VANE J. R.. Introduction: Mechanism of Action of NSAIDs. Rheumatology [online] 1996 April, 35(suppl 1):1-3 [viewed 10 July 2014] Available from: doi:10.1093/rheumatology/35.suppl_1.1
  2. BARNES PETER J. How corticosteroids control inflammation: Quintiles Prize Lecture 2005. [online] 2009 January, 148(3):245-254 [viewed 10 July 2014] Available from: doi:10.1038/sj.bjp.0706736
  3. CRONSTEIN BN, NAIME D, OSTAD E. The antiinflammatory mechanism of methotrexate. Increased adenosine release at inflamed sites diminishes leukocyte accumulation in an in vivo model of inflammation. J Clin Invest [online] 1993 Dec, 92(6):2675-2682 [viewed 10 July 2014] Available from: doi:10.1172/JCI116884