Ординатура / Офтальмология / Английские материалы / Clinical Ophthalmology A Systematic Approach 7th Edition_Kanski, Bowling_2011

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Fig. 8.10 Progression of scleromalacia perforans. (A) Asymptomatic necrotic patch; (B) thinning and exposure of underlying uvea

(Courtesy of R Bates – fig. A; C Barry – fig. B)

Posterior scleritis

Posterior scleritis is a serious, potentially blinding condition, which is often misdiagnosed and treated very late. The age at onset is often under the age of 40 years. The disease is bilateral in 35% of cases. It is important to remember that the inflammatory changes seen in posterior and anterior scleral disease are identical and can arise in both segments simultaneously or separately. The presence of anterior scleritis is a great help if posterior scleritis is suspected but it only occurs in a minority of cases. Patients with posterior scleritis can go blind extremely rapidly, so correct, early diagnosis is crucial. Young patients are usually healthy but about a third of those over the age of 55 years have associated systemic disease.

Diagnosis

1Presentation may be with discomfort or pain. Surprisingly pain does not correlate to the severity of orbital inflammation but tends to be more severe in those with accompanying orbital myositis. Tenderness to palpation is very common but photophobia is not a dominant feature.

2Signs

aExudative retinal detachment occurs in almost 25% of cases (see Fig. 16.59).

bUveal effusion characterized by exudative retinal detachment and choroidal detachment (Fig. 8.11A).

cChoroidal folds represent an anterior displacement of the choroid. They are usually confined to the posterior pole and run horizontally (Fig. 8.11B).

dSubretinal mass characterized by a yellowish-brown elevation which may be mistaken for a choroidal tumour.

eDisc oedema with an accompanying slight reduction of vision is common. It is caused by spread of the granulomatous process into the orbital tissue and the optic nerve. Treatment must not be delayed in these patients as vision can be lost rapidly due to ischaemia.

fMyositis is common and gives rise to diplopia, pain on eye movement, tenderness to touch and redness around a muscle insertion.

g Proptosis is usually mild and frequently associated with ptosis.

hOther features occasionally present include glaucoma, periorbital oedema, chemosis and conjunctival injection.

3Ultrasound is extremely useful in showing increased scleral thickness, scleral nodules and separation of Tenon capsule from the sclera. Fluid in Tenon's space gives rise to the characteristic ‘T’ sign in which the stem of the T is formed by the optic nerve on its side and the cross bar by the gap containing fluid (Fig. 8.12A). Ultrasonography will also show disc oedema, choroidal folds or retinal detachment.

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4MR and CT (Fig. 8.12B) may show scleral thickening and proptosis.

Fig. 8.11 Signs of posterior scleritis. (A) Uveal effusion; (B) choroidal folds

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Fig. 8.12 Special investigations in posterior scleritis. (A) B-scan shows scleral thickening and fluid in sub-Tenon space; (B) axial CTshows right scleral thickening and proptosis

Differential diagnosis

1Subretinal mass must be differentiated from a granuloma associated with some other pathology, amelanotic choroidal melanoma, choroidal metastasis and choroidal hemangioma.

2Choroidal folds, retinal striae and disc oedema may also occur in orbital tumours, orbital inflammatory disease, thyroid eye disease, papilloedema and hypotony.

3Exudative retinal detachment also occurs in Vogt–Koyanagi–Harada (VKH) syndrome and central serous retinopathy.

4Orbital cellulitis may cause proptosis and periocular oedema but unlike posterior scleritis it is associated with marked pyrexia.

Important systemic associations of scleritis

Rheumatoid arthritis

Rheumatoid arthritis (RA) is an autoimmune systemic disease characterized by a symmetrical, destructive, deforming, inflammatory polyarthropathy, in association with a spectrum of extra-articular manifestations and circulating antiglobulin antibodies, termed rheumatoid factor. It is much more common in females than males.

1 Presentation is often in the 3rd decade with joint swelling, usually of the hands.

2Signs

•Symmetrical arthritis of the small joints of the hands typically involving the proximal interphalangeal and spares the distal interphalangeal joints.

•Joint instability may result in subluxation and deformities (Fig. 8.13A), such as ulnar deviation of the metacarpophalangeal joints.

•Less frequent involvement of the feet, shoulders, elbows, hips and cervical spine.

•Skin involvement includes subcutaneous nodules over bony prominences, and vasculitis which may cause ulceration.

3Complications include pulmonary nodules and fibrosis, multifocal neuropathy, septic arthritis, secondary amyloidosis and carpal tunnel syndrome.

4Scleritis. RA is by far the most common systemic association of scleritis. Patients with non-necrotizing scleritis usually have mild joint disease whereas necrotizing disease tends to affect patients with severe long-standing rheumatoid disease with extra-articular manifestations, most notably rheumatoid nodules.

5Other ocular manifestations include KCS (secondary Sjögren syndrome), ulcerative keratitis and acquired superior oblique tendon sheath syndrome (very rare).

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Fig. 8.13 Important systemic associations of scleritis. (A) Severe deformities of the hands in rheumatoid arthritis; (B) CTshows lung cavitation in Wegener granulomatosis; (C) saddle-shaped nasal deformity in relapsing polychondritis; (D) purpura in polyarteritis nodosa

(Courtesy of M Zatouroff, from Physical Signs in General Medicine, Mosby 1996 – fig. A; JA Nerad, KD Carter and MAAlford, from Oculoplastic and Reconstructive Surgery, in Rapid Diagnosis in Ophthalmology, Mosby 2008 – fig. B; C Pavésio – fig. C)

Wegener granulomatosis

Wegener granulomatosis is an idiopathic, multisystem granulomatous disorder characterized by generalized small vessel vasculitis affecting predominantly the respiratory tract and the kidneys. It affects males more commonly than females.

1Presentation is in the 5th decade, often with pulmonary symptoms.

2Signs

•Upper respiratory tract involvement by necrotizing granulomatous inflammation may result in perforation of the nasal septum, saddle-shaped nasal deformity and nasal-paranasal fistulae.

•Lower respiratory tract involvement may result in nodular lesions, infiltrates and cavitation with fluid levels (Fig. 8.13B).

•Necrotizing glomerulonephritis.

•Cutaneous vasculitis and bullae.

•Focal vasculitis involving the spleen, heart and adrenals.

3 Diagnostic tests. Anti-neutrophil cytoplasic antibodies (c-ANCA) are found in over 90% of patients with active disease.

4Scleritis may be rapidly progressive, necrotizing and granulomatous.

5Other ocular manifestations include peripheral ulcerative keratitis, occlusive retinal vasculitis, orbital inflammatory disease, nasolacrimal obstruction, dacryocystitis and rarely tarsal-conjunctival disease.

Relapsing polychondritis

Relapsing polychondritis is a rare idiopathic condition characterized by small vessel vasculitis involving cartilage resulting in recurrent, often progressive, inflammatory episodes involving multiple organ systems.

1Presentation is most frequently in the 5th decade with swelling of cartilage.

2Signs

•Recurrent swelling of the pinnae.

•Involvement of the tracheobronchial cartilage may give rise to hoarse voice, cough and stridor.

•Collapse of the nasal cartilage resulting in a ‘saddle-shaped’ deformity (Fig. 8.13C).

•Cardiac valve dysfunction.

•Non-erosive inflammatory polyarthritis.

•Cochlear or vestibular damage resulting in neurosensory hearing loss, tinnitus, or vertigo.

3 Scleritis is often intractable and may be necrotizing or non-necrotizing.

4Other ocular manifestations include acute anterior uveitis.

Polyarteritis nodosa

Polyarteritis nodosa (PAN) is an idiopathic, potentially lethal, collagen vascular disease affecting medium-sized or small arteries. It is three times more common in males than in females. Ocular involvement may precede the systemic manifestations by several years.

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1Presentation is in the 3rd–6th decades with tachycardia, myalgia, arthralgia, fever and weight loss.

2Signs

•Cutaneous signs include purpura (Fig. 8.13D), dermal infarcts and livedo reticularis.

•Muscular weakness and tenderness.

•Renal involvement and hypertension.

•Coronary arteritis which may lead to heart failure and myocardial infarction.

•Gastrointestinal bleeding or an acute abdominal crisis.

•Stroke or multifocal neuropathy.

3 Diagnostic tests show eosinophilia, hypergammaglobulinaemia and necrotizing lesions on skin biopsy.

4Scleritis is often aggressive and necrotizing although other types may also occur.

5Other ocular manifestations include peripheral ulcerative keratitis, orbital pseudotumour and occlusive retinal periarteritis.

Treatment of immune-mediated scleritis

1Topical steroids do not affect the natural history of the scleral inflammation, but may relieve symptoms and oedema in nonnecrotizing disease.

2Systemic NSAIDs should be used only in non-necrotizing disease. There is little to choose between various agents in terms of relief of pain or regression of physical signs. It is unlikely that using them in combination will provide more effective relief than using them singly. Because there is a large variation in individual responses to NSAIDs, it is often necessary to try a number of different drugs before finding one that provides adequate relief of symptoms.

Guidelines for prescribing an NSAID:

•Use a drug with which you are familiar.

•Prescribe cheaper, established drugs.

•Prescribe only one drug at a time, in adequate dosage.

•Consider COX-2 specific drugs for elderly patients or if there is a past history of peptic ulceration, but note that there are concerns regarding their effects on the cardiovascular system.

•Prescribe for 2 weeks and review.

3Periocular steroid injections may be used in non-necrotizing and necrotizing disease but their effects are usually transient.

4Systemic steroids are used when NSAIDs are inappropriate or ineffective (necrotizing disease). The dose of prednisolone is 1.0 –1.5 mg/kg/day. If a faster effect is required the drug should be administered intravenously.

5Cytotoxic agents are usually necessary whenever disease activity is not completely controlled with steroids alone, or as a steroidsparing measure in patients requiring long-term treatment. In patients with an underlying systemic vasculitis such as Wegener granulomatosis or PAN this form of therapy may also be life-saving. The most frequently used drugs are cyclophosphamide, the drug of choice in Wegener disease, azathioprine, mycophenolate mofetil (CellCept®) and methotrexate.

6Immune modulators such as ciclosporin and tacrolimus are less useful as long-term therapy but may be considered as a shortterm measure in acute presentations before a cytotoxic agent is able to exert its action.

7Specific antibodies such as infliximab and rituximab show promise.

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Infectious scleritis

Infectious scleritis is rare but may be difficult to diagnose because the initial clinical features may be similar to those of immune-mediated disease. In some cases infection may follow surgical or accidental trauma, severe endophthalmitis, or may occur as an extension of primary corneal infection.

Causes

1Herpes zoster it the most common infective cause. Necrotizing scleritis is extremely resistant to treatment and may result in a punched-out area in the sclera (Fig. 8.14A) or a thinned scleral patch.

2Tuberculous scleritis is rare and difficult to diagnose. The sclera may be infected by direct spread from a local conjunctival or choroidal lesion, or more commonly by haematogenous spread. Clinically involvement may be nodular (Fig. 8.14B) or necrotizing.

3Leprosy. Diffuse scleritis is associated with severe recurrent reactions. Nodular scleritis may occur in lepromatous leprosy. Necrotizing disease may occur as a result of scleral infection or as part of an immune response.

4 Syphilis. Diffuse anterior scleritis may occur in secondary syphilis. Occasionally scleral nodules may be seen in tertiary syphilis. 5 Lyme disease. Scleritis is common but typically occurs long after initial infection.

6Other causes include fungi (Fig. 8.14C), P. aeruginosa and Nocardia.

Fig. 8.14 Infectious scleritis. (A) Focal necrosis due to herpes zoster; (B) nodular tuberculous disease; (C) fungal infection

(Courtesy of R Fogla – fig. B, C Barry – fig. C)

Treatment

Once the infective agent has been identified, specific antimicrobial therapy should be initiated. Topical and systemic steroids may also be used to reduce the inflammatory reaction. If appropriate, surgical debridement not only facilitates the penetration of antibiotics but also debulks the infected scleral tissue.

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Scleral discoloration

Alkaptonuria

1Inheritance is AR.

2Defect in homogentisic acid oxidase results in accumulation of homogentisic acid in collagenous tissues such as cartilage and tendon (ochronosis – Fig. 8.15A).

3Systemic features include dark urine (Fig. 8.15B), dark sweat stains, greyish pigmentation of nasal cartilage and ear lobes, spinal disc degeneration (Fig. 8.15C) and arthropathy.

4Ocular manifestations include bluish-grey or black generalized pigmentation of the sclera and the tendons of horizontal recti associated with discrete pigmented globules (Fig. 8.15D).

Fig. 8.15 Alkaptonuria. (A) Histology of scleral ochronosis; (B) dark urine with normal for comparison; (C) spinal disc degeneration; (D) pigmentation of the sclera and horizontal rectus tendons associated with pigment globules

(Courtesy of J Harry and G Misson, from Clinical Ophthalmic Pathology, Butterworth-Heinemann, 2001 – fig. A)

Haemochromatosis

1Inheritance is AR.

2Systemic features are caused by increased iron absorption and deposition in various organs. The classic triad (bronze complexion, hepatomegaly and diabetes mellitus) is unusual; more common is hypogonadism, cardiomyopathy, arthropathy and cirrhosis. Serum iron and ferritin are elevated.

3Ocular manifestations include dry eye, rusty-brown perilimbal conjunctival and scleral discoloration.

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Blue sclera

Blue discoloration is caused by thinning or transparency of scleral collagen with visualization of the underlying uvea (Fig. 8.16). Important causes include the following:

Fig. 8.16 Blue sclera

(Courtesy of M Zatouroff, from Physical Signs in General Medicine, Mosby 1996)

Osteogenesis imperfecta

Osteogenesis imperfecta is an inherited disease of connective tissue, usually caused by defects in the synthesis and structure of Type 1 collagen. There are multiple types, at least two of which have ocular features.

Type I

1Inheritance is AD.

2Systemic features include few fractures with little or no deformity, hyperextensible joints, dental hypoplasia (Fig. 8.17A), deafness and easy bruising.

3Ocular manifestations include blue sclera, megalocornea and corneal arcus.

Fig. 8.17 Osteogenesis imperfecta. (A) Dental hypoplasia; (B) multiple fractures in type IIA

(Courtesy of BJ Zitelli and HW Davis, from Atlas of Pediatric Physical Diagnosis, Mosby 2002 – fig. B)

Type IIA

1 Inheritance is AD or sporadic.

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