Scleritis


Fig. 14.1

Scleritis with characteristic blue hue



The most widely used classification system for scleritis was published by Watson and Heyreh in 1976 and divides the disease into anterior and posterior subtypes, based on whether the inflammation affects the sclera anterior or posterior to the insertion of the rectus muscles (Watson and Hayreh 1976). Anterior scleritis is subdivided into diffuse nodular, necrotizing with inflammation and necrotizing without inflammation (scleromalacia perforans). Posterior scleritis can be subdivided into diffuse, nodular and necrotizing variants.


Posterior scleritis is defined by the involvement of the sclera posterior to the insertion of the rectus muscles (Accorinti et al. 2013). It is a severe form of scleritis and is frequently associated with complications such as uveitis, serous retinal detachment, optic disc oedema, peripheral choroiditis and multifocal subretinal exudates that can be a significant threat to vision (Albini et al. 2005a) (Fig. 14.2). Posterior scleritis has been reported in 2–11% of scleritis cases (Sainz de la Maza et al. 2012; Keino et al. 2010; Lavric et al. 2016). The diagnosis of posterior scleritis is often difficult. In an Indian study, 8.5% of the 94 cases of scleritis seen in a tertiary referral clinic were diagnosed as posterior scleritis; however, each of these cases were initially misdiagnosed by the referring ophthalmologist prior to evaluation in the tertiary clinic (Gonzalez-Gonzalez et al. 2014).

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Fig. 14.2

Subretinal granuloma with posterior scleritis


A scleritis severity grading scale for anterior scleritis was proposed and tested by McCluskey and Wakefield in 1991, using parameters of tenderness, area of inflammation, presence of nodules, necrosis, corneal involvement, vitreous cells and retinal detachment (McCluskey and Wakefield 1991). A score of 11 or higher carries a high chance of visual loss, associated disease, scleral necrosis, a diminished response to systemic steroids and a higher requirement for the use of immunomodulatory drugs. The scoring system uses some of the clinical signs seen in patients with posterior scleritis, but it is not specifically designed to assess posterior scleritis.


Clinical Features


The mean age of onset of scleritis is in the fifth decade, with females accounting for 56–71% of patients. Initially, scleritis is frequently unilateral, but bilateral disease develops in 35–51% of patients (McCluskey et al. 1999; Raiji et al. 2009; Jabs et al. 2000). In Watson’s study, posterior scleritis was found to be predominantly unilateral (McCluskey et al. 1999; Watson and Hayreh 1976). A correlation between bilateral posterior scleritis and higher anti-nuclear antibodies (ANA) titres has been reported, although the ANA titre is usually not a good measure of disease severity in other autoimmune diseases, such as SLE (Gonzalez-Lopez et al. 2016).


The characteristic feature of scleritis is the subacute onset of deep, boring, periocular pain, which may radiate to the temple and jaw. The pain is typically worse at night, interfering with sleep and waking the patient early in the morning. It may be exacerbated by eye movement or accommodation and can be so severe as to interfere with normal activities—particularly in patients with necrotizing scleritis with inflammation. Pain is not always a prominent feature, particularly patients with posterior scleritis or those taking anti-inflammatory or immunosuppressive medications for an associated systemic disease, such as rheumatoid arthritis. Approximately, 30% of patients with posterior scleritis present with reduced vision (McCluskey et al. 1999).


The clinical signs of scleritis vary according to the location of the inflammation and its severity. Additionally, complications of scleritis, such as macula oedema, subretinal mass lesions, uveitis, raised intraocular pressure, cataract, uveal effusion, exudative retinal detachment and optic disc oedema, may be evident due to spillover of the scleral inflammation into adjacent structures and are often the clinical manifestations that lead to the patient seeking medical attention.


Posterior scleritis is commoner than previously recognized. It may occur in association with anterior scleritis, in which case the hallmark features of scleral oedema and congestion of the deep episcleral vascular plexus will be present. If it occurs in isolation, the eye may appear white although inflamed posterior sclera may sometimes be detected at the extremes of gaze (Okhravi et al. 2005). In a large series of patients with posterior scleritis (McCluskey et al. 1999), serous retinal detachment was the most common posterior segment finding (Table 14.1). In 17% of cases, there were no signs. B-scan ultrasonography is the key to diagnosis and demonstrates increased thickness of the ocular coats (greater than 2.0 mm is considered abnormal), fluid in Tenon’s capsule (T-sign) (Fig. 14.3), optic disc swelling, retinal detachment and scleral nodules (McCluskey et al. 1999).


Table 14.1

Common symptoms and signs of posterior scleritis


















































Symptoms

Clinical signs

Periocular pain

Conjunctival chemosis


Blurred vision

Conjunctival hyperemia


Headache

Choroidal folds


Photophobia

Serous retinal detachment


Floaters

Anterior chamber reaction (cell or flare)

 

Macula oedema

 

Associated anterior scleritis

 

Optic nerve swelling

 

Vitreous cells

 

Proptosis

 

Ocular hypertension

 

Vasculitis

 

Peripheral keratitis


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Fig. 14.3

33-year-old female with idiopathic posterior scleritis. She had a history of intermittently red (temporal), painful eye for 2–3 weeks. Visual acuities were 6/18 in right eye 6/6 in left eye, and IOP was normal. (a) Colour fundus image showing choroidal folds and temporal detachment with fluid tracking through macula. (b) OCT images of patient showing serous detachment and choroidal folds. (c) B scan of the right eye showing increased thickness of sclera and T sign


Aetiology


Posterior scleritis may be idiopathic in origin (Fig. 14.3), although it is critical to exclude local or systemic infection, systemic vasculitis or associated systemic autoimmune disorder. Other causes include surgically induced scleral infection following ocular surgery (Fig. 14.4), physical trauma, and drug induced, in particular due to bisphosphonate therapy. It can also be associated with intraocular and orbital neoplasms. In many cases, a presentation of scleritis can be the first clinical sign of a severe systemic disease. Between 36 and 57% (Berchicci et al. 2014; Akpek et al. 2004; Lavric et al. 2016) cases of posterior scleritis are associated with systemic disease. In contrast, 5–15% of cases are due to infection (Accorinti et al. 2013; Albini et al. 2005a).

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Fig. 14.4

Surgically induced necrotizing scleritis (SINS)


Associated systemic disease in patients with posterior scleritis are either inflammatory disorders, such as rheumatoid arthritis, psoriatic arthritis and reactive arthritis, systemic autoimmune disease, such as systemic lupus erythematosus, and Sjogren’s syndrome or systemic vasculitis, such as the anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (Artifoni et al. 2014) (Fig. 14.5). One review (Hakin and Watson 1991) reported that over 50% of patients had an associated systemic disease, whereas others have found a range of between 29 and 37.7% (Lavric et al. 2016; McCluskey et al. 1999).

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Fig. 14.5

(a) Bilateral cANCA necrotizing scleritis with associated anterior uveitis in a 68-year-old man. (b, c) CT scan of chest in the same patient shows multiple cavitating lesions throughout the lung


Systemic Autoimmune Disease Associations


In a large series of patients with both anterior and posterior scleritis and an associated systemic disease, 78% had a pre-existing diagnosis, 14% were diagnosed as a result of the initial evaluation and 8.4% developed a systemic disease during follow-up. Systemic vasculitis was less likely to have been previously diagnosed than other rheumatic diseases (59% vs. 84%) and more likely to be diagnosed as a result of the initial evaluation (27% vs. 9%) (Akpek et al. 2004). Subsequent studies have reported similar results and have recommended a workup to exclude primary vasculitic disease even in patients with scleritis and a known non-vasculitic systemic disease (Raiji et al. 2009).


A UK tertiary referral centre series of patients with posterior scleritis reported that 29% of patients had an associated systemic disease. Patients older than age 50 years and those who developed an associated anterior scleritis had a significantly increased risk of associated systemic autoimmune disease (McCluskey et al. 1999). In a study by Lavric et al., rheumatoid polyarthritis (12.28%), systemic lupus erythematous (4.38%) and pANCA(+) systemic vasculitis (5.26%) were the most frequent systemic associations of posterior scleritis (Lavric et al. 2016). Uncommon and rare associations include: relapsing polychondritis, polyarteritis nodosa, Takayasu disease, giant cell arteritis, juvenile idiopathic arthritis, Vogt-Koyanagi-Harada disease, sarcoidosis, lymphoma, carcinoma of the lung, Cogan syndrome, congenital erythropoietic porphyria and graft-versus-host disease following allogenic bone marrow transplantation (Okhravi et al. 2005).


Scleritis occurs in 0.15–6.3% of patients with RA; conversely up to 30% of patients presenting with scleritis will have RA (Hakin and Watson 1991). The most common phenotype is diffuse anterior scleritis; however, there are no clinical features to distinguish the scleritis seen in patients with RA from that in other conditions, except that scleromalacia perforans only occurs in patients with advanced vasculitic RA. Patients with RA-related scleritis tend to be older and are more likely to develop necrotizing scleritis, decreased vision and peripheral ulcerative keratitis, compared with patients with idiopathic scleritis (Sainz de la Maza et al. 1994). The advent of effective biological therapy of RA has resulted in a dramatic decrease in the incidence of RA-related posterior scleritis (Artifoni et al. 2014).


Scleritis (both anterior and posterior) occurs in approximately 10% of patients with granulomatous polyangiitis (GPA) (Hoffman et al. 1992). The clinical features of scleritis can be helpful in pointing to a diagnosis of GPA; there may be a raised granulomatous mass and the inflammatory changes involve conjunctiva, episclera and sclera. Patients with GPA-related scleritis are more likely to develop necrotizing scleritis, decreased vision and peripheral ulcerative keratitis compared with patients with scleritis associated with any other systemic vasculitic disease (Sainz de la Maza et al. 1995).


Scleritis occurs in approximately 40% of patients with relapsing polychondritis (Hoang-Xaun et al. 1990). The most common phenotype is diffuse anterior scleritis but it can be of any type. Along with RA-related scleritis, it is considered a disease of intermediate severity (Sainz de la Maza et al. 1995). Although the inflammation rarely causes destruction of the globe or decreased vision, the pain may be very severe and resistant to treatment (Hakin and Watson 1991). Scleritis occurs uncommonly in patients with systemic lupus erythematosus. It is usually diffuse or nodular and considered relatively mild. Scleritis associated with the spondyloarthropathies is similar. It can be quite resistant to treatment until the systemic disease is brought under control (Hakin and Watson 1991).


Infectious Scleritis


It is critical not to miss a diagnosis of infectious posterior scleritis. Infectious scleritis should be suspected in patients with a history of ocular trauma or ocular surgery such as scleral buckling procedures, recurrent attacks of herpes zoster or simplex and systemic review consistent with infection or progression of disease whilst on immunomodulatory therapy (Bhat et al. 2009) (Fig. 14.6). Unifocal or multifocal scleral abscesses and contiguous corneal infiltration may be present (Jain et al. 2009). Viruses, bacteria, fungi and parasites can all cause infectious scleritis, either by direct invasion of organisms or via an immune response induced by the organism (Okhravi et al. 2005). The most common causative pathogens include: varicella zoster virus (VZV), herpes simplex virus (HSV), Treponema pallidum, Mycobacterium spp., Pseudomonas aeruginosa, Acanthamoeba and Aspergillus spp. (Okhravi et al. 2005).

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Fig. 14.6

36-year-old male with herpes zoster ophthalmicus. He had no visual symptoms or pain, and visual acuities were 6/6 in both eyes. (a, b) Note right optic disc swelling in funds photo. B scan of ultrasonography of the right eye (c) with posterior scleritis compared to left eye (d). (e) Colour fundus photo of the right eye showing partially resolved optic disc swelling with some exudation around the macula. (f) HVFs showing right optic nerve damage secondary to posterior scleritis. (g) Right optic neuropathy after resolution of the posterior scleritis


Posterior scleritis occurs in around 0.87% of cases and up to 8% of all scleritis in patients with a history of herpes zoster ophthalmicus. It often manifests months after an episode (Liesegang 1991; Lavric et al. 2016) (Fig. 14.7). Active herpetic scleral disease is typically diffuse or nodular in subtype; whereas immune-mediated is usually of the necrotizing subtype (Liesegang 1991). There is a high risk of scleral thinning, staphyloma formation and globe perforation (Bhat et al. 2009). HSV-related scleritis is an under recognized clinical entity. It presents as a chronic or recurrent scleritis refractory to conventional therapy.

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Mar 22, 2020 | Posted by in OPHTHALMOLOGY | Comments Off on Scleritis

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