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

kanski 7th

Multifocal vitelliform lesions without Best disease

Occasionally multifocal vitelliform lesions (Fig. 15.28), identical to those in Best disease, may become manifest in adult life and give rise to diagnostic problems. However, in these patients the EOG is normal and the family history is negative. Occasionally Best dystrophy may present with multifocal lesions.

Fig. 15.28 Multifocal vitelliformlesions

(Courtesy of C Barry)

Pattern dystrophy

Pattern dystrophy is a generic term that encompasses several retinal dystrophies exhibiting yellow, orange or grey deposits at the macula that have a variety of morphologies. The lesions are associated with the accumulation of lipofuscin at the level of the RPE. Pattern dystrophy is usually present in isolation but has also been described in patients with myotonic dystrophy, Kjellin syndrome (spastic paraplegia and dementia) and pseudoxanthoma elasticum. The main phenotypes having the following common characteristics are discussed below: (a) AD inheritance, (b) variable expressivity, (c) bilateral symmetrical involvement, (d) relatively benign course and (e) normal ERG but occasionally abnormal EOG.

Adult-onset macular vitelliform dystrophy

In contrast to juvenile Best disease, the foveal lesions are smaller, present later and do not demonstrate similar evolutionary changes.

1Inheritance. It is caused by mutation in the RDS gene on chromosome 6p, as well as the BEST1 gene in common with juvenileonset Best dystrophy.

2Presentation is in the 4th–6th decades with mild to moderate decrease in visual acuity and sometimes metamorphopsia although often the condition is discovered by chance.

3Signs

•Bilateral, symmetrical, round or oval, slightly elevated yellowish subfoveal deposit, about one-third of a disc diameter in size, often centered by a pigmented spot (Fig. 15.29A).

•Associated macular drusen may be seen in some cases.

4 FA shows central hypofluorescence surrounded by a small irregular hyperfluorescent ring (Fig. 15.29B).

849 / 1137

kanski 7th

Fig. 15.29 (A) Adult-onset macular vitelliformdystrophy; (B) FA shows corresponding hyperfluorescence

Butterfly-shaped macular dystrophy

1Inheritance is AD.

2Presentation is in the 2nd–3rd decades usually by chance and occasionally with mild impairment of central vision.

3Signs

•Yellow pigment at the fovea arranged in a triradiate manner (Fig. 15.30A).

•Peripheral pigmentary stippling may be present.

•Atrophic maculopathy may occasionally develop with time.

4 FA shows non-fluorescence of the lesions outlined by hyperfluorescence (Fig. 15.30B).

850 / 1137

kanski 7th

Fig. 15.30 (A) Butterfly dystrophy; (B) FA shows non-fluorescence of the lesion outlined by hyperfluorescence

(Courtesy of Moorfields Eye Hospital)

Multifocal pattern dystrophy simulating fundus flavimaculatus

1Presentation is in the 4th decade with mild impairment of central vision.

2 Signs multiple, widely-scattered, irregular, yellow lesions that may be similar to those seen in fundus flavimaculatus (Fig. 15.31A). 3 FA shows hyperfluorescence of flecks but the choroid is not dark (Fig. 15.31B).

851 / 1137

kanski 7th

Fig. 15.31 (A) Multifocal pattern dystrophy simulating fundus flavimaculatus; (B) FA shows hyperfluorescence but the choroid is not dark

(Courtesy of S Milewski)

Macroreticular pattern dystrophy

1 Presentation is in early childhood.

2Signs

•Initially pigment granules at the fovea.

•Reticular pigmentation develops that spreads to the periphery.

3 FA enhances the characteristic macular changes (Fig. 15.32).

Fig. 15.32 FA of macroreticular pattern dystrophy

(Courtesy of RF Spaide, from Diseases of the Retina and Vitreous, WB Saunders, 1999)

852 / 1137

kanski 7th

North Carolina macular dystrophy

North Carolina macular dystrophy is a very rare non-progressive condition. It was first described in families living in the mountains of North Carolina and subsequently in many unrelated families in other parts of the world.

1 Inheritance is AD with complete penetrance but highly variable expressivity with the gene MCDR1 on 6q16.

2Grading and prognosis

aGrade 1 is characterized by yellow-white, drusen-like peripheral (Fig. 15.33A) and macular deposits which develop during the 1st decade and may remain asymptomatic throughout life.

bGrade 2 is characterized by deep, confluent macular deposits (Fig. 15.33B). The long-term visual prognosis is guarded because some patients develop neovascular maculopathy (Fig. 15.33C) and subretinal scarring.

cGrade 3 is characterized by coloboma-like atrophic macular lesions (Fig. 15.33D) associated with variable impairment of visual acuity.

Fig. 15.33 North Carolina macular dystrophy. (A) Peripheral flecks; (B) confluent macular flecks; (C) early neovascular maculopathy; (D) coloboma-like macular lesion

(Courtesy of P Morse)

Familial dominant drusen

Familial drusen (Doyne honeycomb choroiditis, malattia leventinese) is thought to represent an early-onset variant of age-related macular degeneration.

1Inheritance is AD with full penetrance but variable expressivity. The gene EFEMP1 is on 2p16-21.

2Signs in chronological order.

•Asymptomatic yellow-white, elongated, radially-orientated drusen at the macula develop in the 2nd decade.

•They may involve the disc margin and extend nasal to the disc.

•With age the lesions become more numerous and acquire a honeycomb pattern (Fig. 15.34A).

•Visual symptoms may occur in the 4th–5th decades due to RPE degeneration (Fig. 15.34B), geographic atrophy and occasionally CNV.

3Investigations

aFA shows hyperfluorescence of the lesions that may be more numerous (Fig. 15.35A and B) than seen clinically (Fig. 15.35C and D).

bERG is normal.

c EOG is subnormal in patients with advanced disease.

853 / 1137

kanski 7th

Fig. 15.34 (A) Familial dominant drusen; (B) with RPEdegeneration

(Courtesy of Moorfields Eye Hospital)

Fig. 15.35 Familial dominant drusen. (A and B) FA shows more numerous lesions than seen clinically (C and D)

(Courtesy of C Barry)

Sorsby pseudoinflammatory dystrophy

Sorsby pseudoinflammatory macular dystrophy, also referred to as hereditary haemorrhagic macular dystrophy, is a very rare condition that results in bilateral visual loss in the 5th decade of life.

1 Inheritance is AD with full penetrance but variable expressivity, with the gene TIMP3 is on 22q12.13.

2Presentation is in the 3rd decade with nyctalopia or sudden visual loss due to exudative maculopathy in the 5th decade.

854 / 1137

kanski 7th

3Signs in chronological order:

•Yellow-white, confluent, drusen-like deposits along the arcades, nasal to the disc and mid-periphery (Fig. 15.36A).

•Severe visual loss occurs due to exudative maculopathy secondary to CNV (Fig. 15.36B) and subretinal scarring (Fig. 15.36C).

•Peripheral chorioretinal atrophy may occur by the 7th decade and result in loss of ambulatory vision.

4 ERG is initially normal but may be subnormal in late disease.

5Prognosis is universally poor.

Fig. 15.36 Sorsby pseudoinflammatory macular dystrophy. (A) Confluent flecks nasal to the disc; (B) exudative maculopathy; (C) subretinal scarring in end-stage disease

(Courtesy of Moorfields Eye Hospital – fig. B)

Benign concentric annular macular dystrophy

1Inheritance is AD.

2Presentation is in adult life with very mild impairment of central vision.

3 Signs. Bull's eye maculopathy associated with slight vascular attenuation but a normal disc.

4VF shows a paracentral ring scotoma.

5FA shows an annular RPE window defect.

6Prognosis is good in the majority of cases although a minority develop progressive loss of visual acuity and nyctalopia.

Central areolar choroidal dystrophy

1 Inheritance is AD with the gene locus on 17p although linkage to other genes has been described.

2Presentation is in the 3rd–4th decades with gradual impairment of central vision.

3Signs in chronological order:

•Non-specific foveal granularity.

•Well-circumscribed RPE atrophy and loss of the choriocapillaris at the macula (Fig. 15.37A).

•Slowly expanding geographic atrophy with prominence of large choroidal vessels (Fig. 15.37B and C).

4 Prognosis is poor with severe visual loss occurring by the 6th or 7th decade.

855 / 1137

kanski 7th

Fig. 15.37 Progression of central areolar choroidal dystrophy. (A) Early; (B) intermediate; (C) end-stage

Dominant cystoid macular oedema

1Inheritance is AD with the gene locus on 7p.

2 Presentation is in the 1st–2nd decades with gradual impairment of central vision.

3Signs. Bilateral cystoid macular oedema.

4FA shows a flower-petal pattern of leakage at the fovea.

5Prognosis is poor because the oedema does not respond to treatment with systemic acetazolamide and geographic atrophy inevitably ensues.

Sjögren–Larsson syndrome

Sjögren–Larsson syndrome is a neurocutaneous disorder characterized by congenital ichthyosis, spasticity, convulsions and mental handicap with reduced life expectancy. The basic metabolic defect is deficient activity of fatty aldehyde dehydrogenase.

1Inheritance is AR with gene locus on 7p11.

2 Presentation is with photophobia and poor vision.

3Signs

•Bilateral, glistening yellow-white crystalline deposits at the macula (Fig. 15.38) which appear during the first 2 years of life and become more numerous with time.

•The presence of the macular lesions is thought to be a cardinal and perhaps pathognomonic sign of the syndrome.

•Other features include cataract, colobomatous microphthalmos and pigmentary retinopathy.

3VEP is abnormal.

856 / 1137

kanski 7th

Fig. 15.38 Macular crystals in Sjögren–Larsson syndrome

(Courtesy of D Taylor and C S Hoyt, from Pediatric Ophthalmology and Strabismus, Elsevier Saunders 2005)

Familial internal limiting membrane dystrophy

1Inheritance is AD.

2Presentation is in the 3rd–4th decades with visual loss.

3 Signs. The posterior pole manifests a glistening inner retinal surface (Fig. 15.39).

4ERG shows a selective diminution of the b-wave.

5Prognosis is poor with severe visual loss occurring by the 6th decade due to retinoschisis, retinal oedema and retinal folds.

Fig. 15.39 Familial internal limiting membrane dystrophy

(Courtesy of J Donald M Gass, from Stereoscopic Atlas of Macular Diseases, Mosby 1997)

Copyright © 2011 Elsevier Inc.All rights reserved. Read our Terms and Conditions of Use and our PrivacyPolicy.

If you find this useful please saythanks in your way: dramroo

857 / 1137

kanski 7th

Generalized choroidal dystrophies

Choroideremia

Choroideremia is a progressive, diffuse degeneration of the choroid, RPE and retinal photoreceptors.

1Inheritance is XLR with the locus on Xq21.2 (CHM gene).

2Female carriers show mild, patchy peripheral RPE atrophy and mottling (Fig. 15.40). However, visual acuity, peripheral fields and ERG are usually normal although some carriers may complain of nyctalopia. It is important to identify carriers because:

•50% of their sons will develop choroideremia.

•50% of their daughters will also be carriers of the disease.

3Presentation is in the 2nd–3rd decades with nyctalopia, followed some years later by loss of peripheral vision.

4Signs

•Mid-peripheral RPE abnormalities that may, on cursory examination, resemble RP.

•Atrophy of the RPE and choroid spreads peripherally and centrally (Fig. 15.40B).

•End-stage disease shows a few large choroidal vessels coursing over the bare white sclera, vascular attenuation and optic atrophy. In contrast to primary retinal dystrophies, the fovea is spared until late (Fig. 15.40C).

5ERG. Scotopic is non-recordable; photopic is severely subnormal.

6FA shows filling of the retinal and large choroidal vessels but not of the choriocapillaris. The intact fovea is hypofluorescent and is surrounded by hyperfluorescence due to an extensive window defect (Fig. 15.40D).

7Prognosis is very poor; although most patients retain useful vision until the 6th decade, very severe visual loss occurs thereafter.

Fig. 15.40 Choroideremia. (A) Female carrier; (B) advanced disease; (C) end-stage disease; (D) FA shows an intact fovea

(Courtesy of K Nischal – fig. B; S Milewski – figs C and D)

Gyrate atrophy

Gyrate atrophy is a metabolic disorder caused by a mutation of the gene encoding the main ornithine degradation enzyme, ornithine aminotransferase. Deficiency of the enzyme leads to elevated ornithine levels in the plasma, urine, CSF and aqueous humour.

1Inheritance is AR with the gene locus on 10q26.

2 Presentation is in the 1st–2nd decades with myopia and nyctalopia.

3Signs

858 / 1137