lens and cats Flashcards
mittendorf dot is from what embryonic structure
hyaloid artery
epicapsular star is from what embryonic structure?
tunica vasculosa lentis
Peter’s anomaly via what mechanism?
anterior segment dysgenesis/ failure of lens vesicle and surface ectoderm (cornea)at around 33 weeks
Pete’s anomaly is associate with what gene defects
PAX6, PITX2, FOXC1
Peter’s anomaly is associated with what defects?
- central/paracentral leukoma (corneal opacity)
- thinning/absent endothelium/descemet’s
- Iris sticks to cornea (type 1); iris sticks to lens (type 2)
- anterior cortical cataracts
- microspherophakia
- anteriorly displaced lens
What is microspherophakia? It’s associated with what condition(s)?
whole equator of lens can be seen when fully dilated… leading to high refractive power thus high myopia
- primarily Weill-Marchesani syndrome
- Peter’s anomaly
- Alport’s syndrome
- Lowe’s syndrome
- Marfan’s syndrome
what is a feared complication of microspherophakia? what can exacerbate this? what can treat this complication?
Acute angle closure glaucoma.
- Exacerbated by miotics
- Treat with cycloplegics–>to pull the lens posteriorly
Congenital aphakia:
what is primary aphakia vs secondary aphakia?
Primary aphakia is when lens placode does not form
Secondary aphakia is when the forming lens is absorbed.
What is aniridia? unilat or bilat?
no iris (partial or whole) almost always bilateral
nonhereditary aniridia… what two conditions do you have to worry about?
what’s a common complication of aniridia?
Wilm’s tumor
WAGR complex– wilm’s, aniridia, genitourinary, mental Retardation
-early cataract formation
Definition of congenital (aka infantile) cataracts
seen at birth or within 1 year of birth
Most common type of congenital cataract? what are its features? usual pattern of inheritance?
also called zonular.
It has layer of opacification surrounding the nucleus and itself is surrounded by clear cortex.
May have adjacent horseshoe shaped opacity called “riders”
-autosomal dominant
Types of congenital cataracts
lamellar, polar, sutural, cerulean, membranous, coronary, nuclear, capsular, complete
features of anterior polar cataracts. Mode of inheritance. Clinical significance?
-Anterior polar–aka subcapsule and involving cortex.
-autosomal dominant
-usually bilateral, non progressive, no impairment of vision
but could cause anisometropia. sometimes seen with anterior lenticonus, persistent pupillary membranes, microophthalmia
sutural cataracts are also called what?
Stellate cataracts
features of posterior polar cataracts?
Mode of inheritance.
Features of hereditary vs sporadic.
Usually larger and more clinically significant than anterior polar cataracts.
- Associated with capsular fragility
- Autosomal dominant. Inherited is usually bilateral versus sporadic can be unilateral and associated with persistent tunica vasculosa lentil and lenticonus
Sutural cataracts.
Features?
Mode of inheritance?
Clinical relevance?
opacities along the fetal suture lines.
Autosomal dominant
Usually not of clinical significance
Features of coronary cataracts?
a club shaped cortical opacity usually at the periphery and can’t be seen unless dilated.
-autosomal dominant inheritance
Cerulean cataracts are also called what? Features of cerulean cataracts?
Blue dot cataracts.
small bluish opacities on the lens CORTEX.
usually not clinically significant and non progressive
Medical indications for cataract surgery. (4)
- obscured view to back of eye in order to assess for other conditions such as AMD, DR…etc
- dislocated lens
- phacolytic glaucoma, pharmacomorphic glaucoma (due to intumescent lens –rapid thickened–
- phacoantigenic uveitis
Most common indication for cataract surgery?
elective desire to improve vision
What is the key clinical association with congenital nuclear cataracts?
What is a feared complications?
congenital nuclear cataracts tend to be associated with micro-ophthalmic eyes.
Increased risk of aphasic glaucoma (which is the most common long term complication s/p congenital CE)
Capsular cataracts.
features?
clinical significance
involves the anterior lens capsule and epithelium. DOES NOT involve the cortex. Protrudes in to the AC?
Generally not clinically significant
What is it called when the entire lens is opacified in a <1 year old?
Complete cataract