๐๐ก๐จ๐ซ๐จ๐ข๐๐๐ซ๐๐ฆ๐ข๐โฃ
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โ X linked recessive chorioretinal dystrophyโฃ
โ Diffuse, progressive degeneration of the RPE, photoreceptors and choriocapillariesโฃ
โ Mutation in CHM gene codes for REP-1 ( Rab escort protein) , Xq21โฃ
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๐๐๐ญ๐ก๐จ๐ ๐๐ง๐๐ฌ๐ข๐ฌโฃ
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โ Primarily degeneration of RPE cells or choroid or both with secondary degeneration of rods and then conesโฃ
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๐๐ฅ๐ข๐ง๐ข๐๐๐ฅ ๐ ๐๐๐ญ๐ฎ๐ซ๐๐ฌโฃ
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โ Symptomatic during 1st decade of lifeโฃ
โ Nyctalopia/night blindnessโฃ
โ Progresses to peripheral vision in teenage yearsโฃ
โ Spares central vision until 50-70 yearsโฃ
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๐ ๐ฎ๐ง๐๐ฎ๐ฌโฃ
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โ Initial changes begin in midperipheral retinaโฃ
โ Clumping/mottling of pigments at RPEโฃ
โ Well defined areas of hypopigmentation/atrophy with underlying sclera and large choroidal vessels visibleโฃ
โ Post equatorial region just outside vascular arcadesโฃ
โ Advances centripetallyโฃ
โ Associated with PSC, macular edema, CNVโฃ
โ Female carriers asymptomatic - fundus can be normal to full blown choroideremiaโฃ
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๐๐ฅ๐๐๐ญ๐ซ๐จ๐ซ๐๐ญ๐ข๐ง๐จ๐ ๐ซ๐๐ฆโฃ
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โ Reduced scotopic before photopicโฃ
โ Reduction in amplitude of full field ERG and delay in b wave implicit time with minimallyโฃ
increased dark adaptation thresholdsโฃ
โ Extinguished by midlifeโฃ
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๐๐ซ๐๐๐ญ๐ฆ๐๐ง๐ญโฃ
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โ At present, no treatmentโฃ
โ Macular edema - 2% dorzolamideโฃ
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