Ординатура / Офтальмология / Английские материалы / Moorfields Manual of Ophthalmology_Jackson_2007

Acute Anterior Uveitis

Background Acute anterior uveitis (AAU) is the commonest form of acute uveitis accounting for ≈75% of all cases of intraocular inflammation. It is often recurrent, has numerous causes, and is associated with HLA-B27 in 60% of cases.

Symptoms Onset over hours or days of redness, pain, and photophobia. Usually unilateral but may be simultaneously or sequentially bilateral.

Signs

Ocular: Conjunctival (predominately perilimbal) injection and anterior chamber flare and cells are the hallmarks of AAU. Cells are graded by the number observed in an oblique

1 × 1 mm slit beam:

0( – ) 10–20 cells (2+)

Flare is graded as 0–4, with grade 4 representing fibrin deposition. The cornea may show epithelial or stromal changes consistent with herpes zoster virus or less commonly herpes simplex virus infection. Keratic precipitates (KPs) may be large and greasy looking (‘mutton fat’) or fine and small (Fig. 8.1).

Fibrin, hypopyon, iris abnormalities (posterior synechiae [PS], peripheral anterior synechiae [PAS], atrophy, nodules), and raised or low IOP, are variable findings. Posterior segment signs are restricted to a few anterior vitreous cells (spillover) and cystoid macular oedema (CMO). CMO is uncommon, but the most important cause of visual loss.

Systemic : variable, dependent upon any associated disease.

History and examination Ask about the pattern of anterior uveitis (unilateral, bilateral, recurrent) and associated systemic disease, particularly back and joint pain, skin lesions, and gastrointestinal and urinary tract symptoms linked with HLAB27 disorders. Occupational and travel history may suggest brucellosis (abattoir workers, vets), leptospirosis (farmers and sewage workers), or Lyme disease (USA, Scandinavia, Eastern and Middle Europe). Record VA and grade cells and flare. The pattern of signs provides clues to the aetiology:

■Hypopyon : HLA-B27, Behçet’s disease, rarely candida infection, and malignancy.

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■Masquerade syndromes (p. 371).

■Idiopathic

If VA is worse than 6/9 seek posterior segment disease, and if the fundal view is inadequate to exclude intraocular infection refer directly to a uveitis clinic.

Investigations Investigate in clinic, not casualty. Unilateral disease with unremarkable history and examination requires no investigation at first presentation. For recurrent, bilateral, or poorly responsive disease and no suggestive aetiology, restrict initial investigations to CXR, serum ACE, and syphilis serology. Confirmation of HLA-B27 status in a fit person may spare further investigation. Consider additional investigations, e.g. Lyme, Brucella, and Leptospira serology, but only if specifically suggested by the history and signs. If VA is worse than 6/9 and no cause is found, arrange fluorescein angiography or OCT to exclude CMO. If there are symptoms of associated systemic disease, refer for appropriate medical evaluation.

Treatment Attacks of AAU typically last from several days to 6 weeks, but less than 3 months by definition.

■Casualty : The majority of patients can be managed with cycloplegia (G. cyclopentolate 1% t.d.s.), and intensive topical steroid therapy, initially G. prednisolone 1% or G. dexamethasone 0.1% hourly for week 1, 2-hourly for week 2, 6 times daily week 3, q.d.s. for week 4, then reduced every week by one drop/day until clinic review at 6 weeks. Add steroid ointment nocte if inflammation is more marked. Subconjunctival Mydricaine II (0.3 mL) may break new PS. Reserve

subconjunctival betamethasone (4 mg in 1 mL) for severe AAU, usually 4+ cells or fibrin/hypopyon. Tissue plasminogen activator (TPA) is rarely required but has a rapid effect in breaking down fibrin in cases with severe fibrinous response refractory to topical and subconjunctival steroids. Instil povidone-iodine 5% and topical anaesthetic into the conjunctival sac then inject 12.5 mcg in 0.1 mL directly into the anterior chamber using an insulin syringe and needle This can be performed either on the slit lamp or with the patient lying down. No paracentesis is required and the injection can be repeated if necessary. Instruct patients to return quickly if there is a deterioration of vision and persistent pain. For the treatment of uveitic glaucoma see page 309. If an exact aetiology is determined, alternative or additional treatment may be required. Anterior uveitis following trauma is typically relatively mild and usually settles rapidly with less-intensive treatment, e.g. G. dexamethasone 0.1% q.d.s. tapered off over 2–3 weeks.

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Acute anterior uveitis

■Clinic : If the inflammation is settling, continue to slowly taper off topical steroids. Reintroduce hourly steroids and above regimen for exacerbations during the tapering period. Rarely, oral steroids are required for very severe cases resistant to subconjunctival and maximal topical treatment, or CMO unresponsive to local steroid injection (p. 343).

Follow–up All children, patients with severe inflammation (fibrin, hypopyon), raised IOP, known steroid responders, and definite or suspected CMO with reduced VA, should be seen within 1 week. Otherwise, arrange clinic review within 6 weeks and then discharge those with uncomplicated and resolved AAU. Advise patients that recurrences are common and to attend casualty if they are symptomatic.

Chronic Anterior Uveitis

Background Arbitrarily defined as anterior uveitis persisting for >3 months. Unlike acute anterior uveitis, it is not associated with HLA-B27.

Symptoms May be asymptomatic or present with only blurred vision.

Signs As for acute anterior uveitis, but the eye may be white and there is a higher incidence of complications (posterior synechiae; peripheral anterior synechiae; raised IOP; cataract; cystoid macular oedema, CMO).

Differential diagnosis

■Systemic disease : juvenile idiopathic arthritis; sarcoidosis.

■Ocular syndromes : Fuchs’ heterochromic cyclitis.

■Infective : herpes zoster ophthalmicus (HZO), herpes simplex virus (HSV), syphilis.

■Chronic idiopathic anterior uveitis : accounts for ≈50% of cases.

■Postoperative inflammation : especially cataract surgery.

Clinical features Patients may have anterior vitreous cells and CMO but no other posterior segment signs. Two wellrecognized types of chronic anterior uveitis are Fuchs’ heterochromic cyclitis (FHC) and herpetic uveitis.

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Chronic anterior uveitis

■Fuchs’ heterochromic cyclitis (FHC): features include white eye; characteristic translucent round or stellate keratic precipitates (KPs) scattered over the whole endothelium (Fig. 8.2); heterochromia (variable); iris stromal atrophy is typically diffuse; PS are absent; cataract is common; raised IOP (25%); vitreous cells and floaters may be considerable; CMO is rare.

■Herpetic uveitis : seek a history of vesicles of HSV or HZO rash, corneal changes (p. 178, p. 182), Sectorial iris atrophy is common. Assess for complications at each visit.

Investigations Arrange CXR, sACE, and syphilis serology if no suggestive aetiology.

Treatment

■Casualty : Treat acute exacerbations and refer to clinic as for AAU (p. 333). Use a weaker steroid (G. prednisolone 0.5% q.d.s.) covered with Oc. aciclovir five times daily for HSV uveitis, even if there is no active epithelial disease.

■Clinic : Taper steroids slowly over months and attempt to stop. In steroid responders, G. rimexolone 1% (Vexol) may control inflammation without raising IOP. Add topical apraclonidine 0.5% t.d.s. and dexamethasone 0.1% if inflammation recurs. FHC does not require topical steroids.

Follow–up Assess and manage complications as they arise. Review after several weeks if topical steroids are stopped to exclude recurrence as this may be asymptomatic. For patients with FHC and normal IOP, arrange baseline disc imaging (photo or HRT) then annual glaucoma screening with an optometrist. Monitor those with elevated IOP in clinic.

Intermediate Uveitis

Background Intermediate uveitis is inflammation centred on the pars plana and peripheral retina. Pars planitis is defined as intermediate uveitis with ‘snowbanking’ and no systemic association. There is no racial or sex bias, with onset typically in childhood or young adult life. Pars planitis rarely presents over the age of 40 years.

Symptoms Bilateral in >80%, although asymmetry is not uncommon and about one-third present with unilateral disease. The history is frequently vague, but floaters from vitreous opacification or blurred vision from cystoid macular oedema (CMO) are common.

Signs The eye is white and the anterior segment usually quiet, or it may demonstrate slight flare, a few cells, and several small keratic precipitates (KPs). Vitreous signs predominate. Cells and opacities are invariable and may aggregate to form ‘snowballs’ concentrated over the inferior peripheral retina (Fig. 8.3). ‘Snowbanking’ is the appearance of a white plaque, typically overlying the inferior pars plana and retina but it can encompass the entire peripheral fundus (Fig. 8.4).

CMO occurs in 25% and is the most important threat to vision. Other findings include mild vasculitis and sheathing of peripheral retinal venules, diffuse retinal oedema, optic disc or peripapillary swelling, and neovascularization of the disc or ‘snowbank’.

History and examination The diagnosis is made by recognizing vitreous signs, an absence of focal choroidal and retinal lesions, or the presence of systemic diseases associated with pars planitis (see differential diagnosis below). Sarcoidosis

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the acuity and presence of CMO (p. 343). In pars planitis, neovascularization is secondary to inflammation, whereas in intermediate uveitis it may be secondary to inflammation, ischaemic retinal vasculitis, or a combination of both. Fluorescein angiography helps with the distinction. Steroids (oral or consider periocular injection in unilateral disease) are used to treat neovascularization secondary to inflammation, and argon laser is used if there is an ischaemic drive to new vessel formation. It may be appropriate to use oral prednisolone for 2 weeks prior to panretinal photocoagulation to dampen the inflammatory response.

Follow–up The majority have a chronic course lasting years with subacute exacerbations and low-grade remissions requiring long-term, periodic follow-up.

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Posterior uveitis

Posterior Uveitis

Background Posterior uveitis may reduce vision in several ways:

■Reversible : cystoid macular oedema (CMO); retinal or disc neovascularization, choroid neovascular membrane, disc swelling, cataract, epiretinal membranes, vitreous changes and retinal detachment.

■Irreversible : macular ischaemia, optic atrophy, glaucoma, and retinal scars.

History and examination Exclude anterior uveitis and its sequelae (p. 333) with slit lamp examination. Dilate and assess vitreous involvement. Use an indirect ophthalmoscope to look for peripheral vitreous condensations (‘snowballs’), ‘snowbanking’, and any associated neovascularization. Define the primary site of inflammation: choroiditis, chorioretinitis, retinitis, or retinochoroiditis. Establish the pattern of vascular involvement. Venous vasculitis is a common and non-specific sign, it may be ischaemic, and sheathing may persist after inflammation subsides. Arterial involvement is less common but associated with serious systemic diseases such as collagen/vascular disease (systemic lupus erythematosus, Wegener’s granulomatosis, polyarteritis nodosa) and Behçet’s syndrome. A combination of arterial and venous vasculitis occurs in Behçet’s syndrome, toxoplasmosis, syphilis, and acute retinal necrosis. Scars are associated with toxoplasmosis, sarcoidosis, presumed ocular histoplasmosis syndrome, punctuate inner choroidopathy, multifocal choroiditis, or may represent Dalen-Fuch’s nodules (sympathetic ophthalmia, Vogt-Koyanagi-Harada syndrome, sarcoidosis). Determine the cause(s) of any visual loss.

Treatment

■Casualty : Exclude infection (e.g. varicella-zoster virus, metastatic endophthalmitis), treat anterior uveitis, and refer urgently to a uveitis clinic, the same day if vision is threatened.

■Clinic : Treat anterior uveitis accompanying posterior uveitis with topical steroids and mydriatics (p. 333). Regardless of the aetiology, the treatment of posterior uveitis is similar, once infection and neoplasia (such as lymphoma) are excluded. Not all patients require treatment; treat only if the eye is being damaged or the vision threatened. The most common