Ординатура / Офтальмология / Английские материалы / Moorfields Manual of Ophthalmology_Jackson_2007

Central Serous Retinopathy

Symptoms Patients with central serous retinopathy (CSR) may complain of blurred central vision, slow recovery from bright light, scotomata and distortion. Symptoms are usually unilateral. The typical patient is male, 30–50 years old, with a type A personality.

Signs These include serous detachment of the sensory retina in the macular area, sometimes with pigment epithelial detachment (Fig. 10.44). Detachment may be difficult to detect in chronic disease.

Classification Acute, chronic, and recurrent.

History and examination Ask about previous episodes, refractive change (increased hyperopia from retinal elevation) and risk factors (pregnancy; local or systemic corticosteroid use; hypertension; emotional stress; allergic respiratory disease). An Amsler grid appears distorted. Previous episodes may leave bilateral atrophic RPE changes in either eye and in chronic disease VA may be poor. Choroidal neovascularization occurs in 3–4%.

Differential diagnosis Consider idiopathic polypoidal choroidal vasculopathy (IPCV), pigment epithelial detachment, optic disc pit, peripheral choroidal tumour, rhegmatogenous retinal detachment, age-related macular degeneration, choroidal inflammation, and idiopathic choroidal effusion.

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Central serous retinopathy

Investigations Fluorescein angiography shows ‘smokestack’ (Fig. 10.45) or more commonly ‘ink-blot’ leakage (Fig. 10.4); test refraction; measure ocular length (A-scan ultrasound); consider cortisol level in some cases. In chronic CSR, angiography

A

B

shows diffuse hyperfluorescence. If the diagnosis is in doubt, ICG angiography may help by showing choroidal hyperfluorescence at a site of normality on fluorescein angiography, and also excludes IPCV.

Treatment Most acute cases resolve spontaneously within 4 months, so observe. Approximately 85% of acute cases retain 6/6 VA, but 30–50% recur. Recurrent or chronic cases have a worse prognosis. Advise against corticosteroid use if possible. Argon laser treatment of a single leaking focus reduces the interval to recovery but does not change the long-term visual prognosis and may risk choroidal neovascularization. Chronic CSR has been treated with macular grid laser and photodynamic therapy although the benefit is unproven at present.

Follow–up 3–6 monthly until resolved.

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Retinitis pigmentosa

Retinitis Pigmentosa

Background Retinitis pigmentosa (RP) is a group of rod–cone dystrophies with heterogeneous modes of inheritance and variable clinical phenotypes, age of onset and severity. Key features are night-blindness (nyctalopia), visual field loss, and bone-spicule retinal pigmentation.

Classification

■By inheritance.

1. Autosomal recessive (AR): 60% of cases.

2. Autosomal dominant (AD): 10–25% of cases. 3. X-linked (XL): 5–18% of cases.

■By phenotype: e.g. sector RP, paravenous, adult onset.

History Ask about: nyctalopia; VA; glare; field loss; visual requirements (driving); consanguinity and associated systemic disorders, especially congenital deafness (Usher’s syndrome), anosmia (Refsum’s syndrome), and polydactyly (Bardet-Biedl syndrome).

Examination Exclude associated changes: myopia; cataracts; glaucoma; vitreous cells; macular oedema; cellophane maculopathy; peripheral telangiectasia. Localized loss of the red colour of the fundus occurs in early disease. Bone-spicules occur in well-established disease. Unlike most fundal pigment changes, they are intraretinal; confirm that they obscure the underlying retinal vessels. Also note their topographical distribution or photograph. Advanced disease shows retinal vessel attenuation, RPE atrophy, and disc pallor (Fig. 10.46).

Examine family members to determine the inheritance pattern. Draw a family pedigree (p. 412). Consider AR inheritance if both parents are normal, more than one sibling is affected (particularly a female), or there is consanguinity. X-linked female carriers may show bone-spicules, altered (tapetal) retinal reflex, and ERG changes. Isolated cases (simplex or sporadic RP)

occur in approximately 40% but many are probably unconfirmed AR.

Retinitis pigmentosa

hypoparathyroidism. Regular cardiac review is recommended.

■Oxalosis : A metabolic AR disorder that produces oxalate deposition with optic atrophy, RPE changes, retinal vascular obstruction, renal, bone, and vascular disease.

■Refsum’s disease : AR elevation of phytanic acid with cataract, anosmia, ectopia lentis, glaucoma, polyneuritis, and ataxia.

Investigations

■Electroretinography : usually shows a markedly reduced or extinguished response. Scotopic amplitudes ≥100 mV suggest a better prognosis.

■Goldmann visual field test: initial field loss is variable, but classically bilateral, symmetric, and midperipheral, with central vision preserved until late.

■Estermann driving fields : for legal requirements see page 688.

■Fluorescein angiography : avoid if possible, as extremely uncomfortable.

■OCT: may confirm macular oedema.

■Fundus autofluorescence : quantifies macular atrophy if it is clinically uncertain.

■Syphilis serology : in doubtful cases.

■Genetic testing : is available for a growing number of inherited diseases.

Management RP requires specialized support. Advise drivers of their obligation to inform the licensing authority (p. 710). Consider:

■Low-vision aids and sunglasses.

■Blind or partial sight registration.

■Cataract surgery. Use low illumination and an IOL with a low risk of posterior capsular opacification and phimosis.

■Acetazolamide sometimes reduces macular oedema. Try

250 mg modified release once daily for 2 weeks and increase to 250 mg b.d. if no improvement. Discontinue treatment if there is still no effect after a further 2 weeks.

has a better prognosis than AR or XL RP. For patient information see, http://www.rcophth.ac.uk/scientific/ publications.html

■Provide contact details of support groups, e.g. British RP Society (p. 710).

■The future role of gene therapy and retinal/RPE transplantation is uncertain.

■Arrange yearly review.

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Cone dystrophy

Cone Dystrophy

Classification

■Stationary : may show only subtle alteration in colour vision, anomalous trichromacy, or rod monochromacy.

■Progressive : includes several conditions: blue cone monochromacy; pure cone degeneration; cone–rod degenerations; benign concentric annular dystrophy; cone dystrophy with supernormal ERG.

■Systemic disease : may coexist with several systemic disorders, including many of the metabolic diseases associated with retinitis pigmentosa (p. 496).

■Toxic : chloroquine, digoxin.

History and examination Ask about VA, colour vision, and problems with bright light. Some forms show mendelian inheritance (usually autosomal recessive), so examine family members and draw a family pedigree (p. 412). Check colour vision with Ishihara plates and, if abnormal, consider Farnsworth-Munsell 100-hue test. Fundoscopy may be normal, but the characteristic finding is macular atrophy or bull’s-eye maculopathy (p. 450).

Investigations Electrophysiology shows cone dysfunction with absent or mild rod involvement.

Management Offer counselling with senior staff, low-vision aids, sunglasses or tinted contact lenses, and blind or partial sight registration, as appropriate. No treatment exists at present.

Follow–up Yearly if patient wishes.

Gyrate Atrophy

Background An autosomal recessive defect of the mitochondrial enzyme ornithine aminotransferase produces hyperornithaemia. Extraocular features tend to be absent or subtle.

Symptoms Typically, night blindness (nyctalopia) occurs in childhood or teens, with loss of visual field and central acuity in later life.

Signs Chorioretinal atrophy with a scalloped border (Fig. 10.47).

History and examination Draw a family pedigree

(p. 412). Exclude associated high myopia and presenile cataract.

Differential diagnosis Consider choroideremia, high myopia, and thioridazine retinopathy.

Investigations Measure serum ornithine, monocular and Estermann driving fields. The ERG and EOG are both abnormal. Fluorescein angiography is not required but shows hyperfluorescence in the affected areas, with leakage at the borders of unaffected retina.

Management Offer counselling with a senior clinician, yearly review, low-vision aids, and blind or partial sight registration as required. Pyridoxine (vitamin B6 ) supplementation and reduced dietary protein may lower serum ornithine levels. The impact on visual function is not certain.

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Choroideremia

Choroideremia

Background X-linked chorioretinal degeneration due to mutations in geranylgeranyl transferase Rab escort protein I.

Symptoms Night blindness (nyctalopia) and visual field loss in young males.

Signs Midperipheral atrophy of the RPE and choriocapillaris with resulting prominence of the choroidal vessels and sclera. Retinal blood vessels are less affected than in retinitis pigmentosa (Fig. 10.48).

History and examination Examine family members and draw a family pedigree (p. 412). Female carriers are generally asymptomatic, but almost invariably show regional irregular fundal pigmentation and patchy RPE atrophy in later life.

Differential diagnosis Consider retinitis pigmentosa, gyrate atrophy, albinism and thioridazine retinopathy.

Investigations Arrange Estermann driving fields if relevant. Fluorescein angiography is rarely needed, but shows reduced background fluorescence and prominent choroidal vessels caused by RPE and choriocapillaris atrophy. Electrophysiology may initially be normal, but marked abnormalities usually develop.

Management Offer genetic counselling with an experienced clinician, annual review, low-vision aids and blind or partial sight registration. No treatment is currently available. The condition is usually slowly progressive with late macular involvement.