Opthalmology :/ Flashcards
Causes of leukocoria?
Leukocoria = white pupil
- Cataracts- most common cause
- Chorioretinal coloboma
- Coats disease (yellow tinge): accumulation of lipid/telangectasia, unilateral, M- 5-9yrs- visual disturbance/strabismus
- Retinal detachment
Malignancy
- Retinoblastoma: leukocoria <5yrs (60% presenting Sx), AD inheritance
- Leukemia
DDx- vitreous hemorrhage= pallor in optic disc (hemorrage in newborn, severe ROP, trauma, leukemia)
Causes of amblyopia?
Strabismic (50%)
- Due to a deviated eye
- Abnormal interaction between two foveas 🡪 different + unfusable images
- Visual cortex suppresses the image from one eye
Refractive/ ametropic (15-20%)
- Unequal refractive errors 🡪 one eye not focused on the fovea
- Most common in hyperopic patients, but MAY occur in myopia / astigmatism
Anisometropic - unequal need for vision correction
Derivational (<5%)
- Congenital cataracts
- Vitreous haemorrhage
- Severe refractory error
15-20% is combined
What vitamin deficiency causes night blindness (nyctalopia)?
Vitamin A deficiency
Abnormalities of pupil
- aniridia
- coloboma
- microcoria
- mydriasis
- dyscoria
- anisocoria
- corectopia
Aniridia: Hypoplastic iris tissue
- Genetic, 2/3rds AD (PAX6, WAGR)
- 75% develop glaucoma
Coloboma: hole in pupillary margin, AD, most inferior
Microcoria: small unreactive pupil, AD/sporadic
Mydriasis: dilated and do not constrict
Dyscoria = abnormal shape of pupil
Corectopia = abnormal position of pupil
Anisocoria= inequality of pupil
Abnormalities of pupil
-Dilated Fixed Pupil
-Tonic Pupil
-Paradoxical Pupil Reaction
-Persistent Pupillary Membrane
-Marcus Gunn
-Leukocoria
-Heterochromia
-Dilated Fixed Pupil
Tonic Pupil: large/no reaction to light (CMT)
Paradoxical Pupil Reaction: constriction in darkness etc- seen in albinism/retinitis pigmentosa
Persistent Pupillary Membrane: remnant of embryology, involutes but can cause vision impairement if persistent
Marcus Gunn: RAPD
Leukocoria: white pupil- cataracts, retinoblastoma, coloboma
Heterochromia: different colour iris, simple AD, Waardernburg (AD, lateral canthi, SNHL)
Horners: miosis, ptosis, anhydrosis (1st hyporthalamus, 2nd cervical chain, 3rd- CN)
Childhood glaucoma- causes/Rx?
> 50% primary- congenital open angle, abnormality of drainage of eye
- Assoc syndromes: Sturge Weber, NF, Stickler, MPS
Secondary: traumatic, Ca, steroid induced, maternal rubella, infection
Triad Sx:
1. Epiphoria (tearing/watery)
2. Photophobia (sensitivity to light)
3. Blepharospasm (eyelid squeezing)
Rx: BB, Alpha agonist, carbonic anhydrase inhibitor
Complications of Myopia
Myopia = near sightedness
- Increasing prevalence, more time on screens/indoors
Complications
- Retinal detachment
- Glaucoma (^ IOP)
- Cataracts
- Macular degeneration
Vernal keratoconjunctivitis - Sx/Cx?
- Severe bilateral chronic
inflammatory process of the upper tarsal conjunctival surface - Increased in atopic kids, M>F, Asian/African background
- Severe ocular itching/photophobia/lacrimation
Cx:
- Giant papillae
- Corneal shield ulcer
Eye abnormalities associated with: Sturge Weber?
Glaucoma, choroidal haemangiomas
Eye abnormalities associated with: OI
Blue sclera, keratoconus
Eye abnormalities associated with: Marfans
Upward lenticonus, keratoconus
Eye abnormalities associated with: Downs syndrome
strabismus, high refractive error, keratoconus, accommodative insufficiency, cataracts, nasolacrimal duct obstruction, blepharitis, and nystagmus.
Eye abnormalities associated with: JIA
Uveitis - JIA most common cause (up to 50%)
- Females
- Oligo-arthritis <4yrs onset
- ANA positive
Glaucoma, cataracts = smaller percentage
CN3 palsy
ALL 3 SO4 LR6
CN3 = oculomotor
- Superior, inferior & medial rectus, inferior oblique
- Elevation, depression, adduction, in/extorsion
- Eyelid levator
Palsy = ptosis, down and out eye
Mostly congenital
Trauma
Compression
Myasthenia may mimic
CN4 palsy
ALL 3 SO4 LR6
CN4= trochlear (dorsal exit from brainstem)
Superior oblique
- incyclotorsion
Cavernous sinus:
Vertical diplopia
