Trisomy

Trisomy 21 – Down syndrome

* 人類最常見的chromosal disorder
* 約有5%為translocation異常

眼表現：

* 合併keratoconus, cataract, myopia（不是hyperopia）
* upslant(mongoloid) palpebral fissure (不是downslant/anti-mongoloid
* Almond-shaped palpebral fissures
* strabismus，通常esotropia（不是exotropia）
* Brushfield's spot
* iris stromal hypoplasia
* optic atrophy
* prominent epicanthal folds
* blepharitis (chronic, cicatricial)

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Trisomy 18 (Edwards syndrome)

* prominent epicanthal folds, ptosis
* blepharophimosis with small or oblique palpebral fissures
* thick lower lid
* hypertelorism (hypotelorism)
* hypoplastic supraorbital ridges
* congenital glaucoma
* conreal opacities
* microphthalmos
* iris and uveal colobomas

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Trisomy 13 (Patau syndrome)

* hypotelorism (有時會是 hypertelorism)
* shallow supraorbital ridges
* absent eyebrow （眉毛不見了？小貓咪叨走了 …）
* epicanthal folds
* cyclopia (rarely)
* corneal couding
* introcular connective tissue, including cartilage
* 多半為microphthalmos, clinical anophthalmos (少見）
* PHPV
* catarct
* uveal coloboma
* retinal dysplasia
* optic nerve hypoplasia, atrophy, colobomas
* anterior "cleavage" syndrome