Misc Flashcards
What is the difference between orbital myositis vs thyroid eye disease?
TED never involves muscle tendon.
Both cause inflammation of the muscle (myositis)
What is a prism diopter?
1 Prism dioptre produces 1cm visible displacement at 100cm towards the prism base.
Congenital syphillis key characteristics and ophthalmic symptoms?
Saddle nosed deformity + Sabre shins + Hutchinson teeth + sensorineural deafness.
Eye involvement of the corneal stroma (via Intersitital keratitis)
Which agar is used to grow acanthamoeba keratitis?
Mccoy Agar
What is grown in the agar below?
A - Sabouraud agar
B - Lowenstein-Jensen
C - McCoy Agar
A - Fungi
B - Mycobacteria TB
C - Obligate intracellular bacteria (Chylmydia, Acanthamoeba)
When are rods depolarised and Hyperpolarised?
Depolarised - Light
Hyperpolarised -Dark
Detachement of the neurosensory retina is more common in which people?
Type A personality type
Males
Stress + Steroid use.
Which condition is characterised by
ATAXIA, OPTHALMOPLEGIA AND AREFLEXIA?
What investigation would show an abnormality?
Miller-Fisher syndrome (Variant of GBS)
Anti-GQ1b
A -Which germ layer contributes the least to ocular layer developments?
B - Name the components different germ cells contribute to?
- Surface (7) + Neural Ectoderm (6)
- Neural crest
- Mesoderm
- Endoderm
Endoerm - Does not contribute to the eye
Surface Ectoderm - Lens, corneal epithelium conjunctiva, eyelids and lashes, lacrimal gland, nasolacrimal system, Meibomian glands
Neural Ectoderm - Neurosensory retina, optic nerve, RPE, iris muscles, ciliary body epithelium, iris epithelium
Mesoderm - Vitreous, Choroid, Ciliary body, Trabecular meshwork, Schlemm’s canal, Extraocular muscle + Obicularis Oculi , Iris, Optic nerve sheath, ocular vascular endothelium
Neural crest - Vitreous, Choroid, Ciliary body, Trabecular meshwork, Schlemm’s canal, Extraocular muscles, Iris stroma, corneal stroma, scleral stroma, Corneal endothelium and Descemet’s membrane, Bony orbit.
Which muscle is first to be affected by thyroid eye disease?
Inferior rectus
IM SLOW
IR>MR>SR> Levator >LR> Obliques
Inability to look up when eye is adducted. (double elevator palsy)
Most common causative organism for neonatal conjunctivitis?
Chlamydia Trochomatis
What does Schwalbe’s line represent?
Anatomical line of the interior surface of the cornea.
TERMINATION of DESCEMET’S MEMBRANE
Name the structures seen through the Goniolens when assessing the iridocillary angle?
Scwalbe’s line, Trabecular meshwork, Scleral spur, Ciliary body
Main differences between Direct and Indirect Opthalmoscopy?
Direct Monocular view Limited field of view (10-15 deg) Have to be very close Hard to use during surgery x15 Mag Virtual and erect image Not very bright No stereoscopic vision (2D Image)
Indirect Binocular view Wide field of view (35 deg) Can be at a distance (35 cm) Can be used during surgery X5 Mag Real and inverted image Very bright Stereoscopic vision (3D Image)
What is the distribution of aqueous humour production?
Production - NPE of ciliary processes (Ciliary Body)
2/3 - Active secretion via ATPase pumps (NA/K)
1/3- Blood vessel ultrafiltration
