General Flashcards
3 structures posterior to the septum
- palpebral lobe of lacrimal gland
- lateral canthal tendon
- trochlea of SO
Silicone oil
Band keratopthy
If emulsified: glaucoma, direct effect on endothelium.
Worse in a phakic patients.
Know that there are 2 types of viscosity to the oil (alters calculation)
If traditional a scan ultrasound moves slower and the eyeball will read longer than it is (you’ll need a higher power lens)
Others thibgs: lens choice (calculations, power spericity,
What is the arcus marginalis
Where septum fuses with peri-orbita at the orbital rim
What are the two vascular arcades of the upper lid
Marginal arcade: at the eyelid margin
Peripheral arcade: just above the top of tarsus (behind levator, in front of muller –> be careful not to hit it in ptosis repair whn you take a bite through levator!)
MRI, T1 is what colour for vitreous and orbital fat?
Vitreous dark on T1, bright on t2
Orbital fat is bright on T1, but turns dark with fat suppression (allows you to see optic nerve better)
List orbital hamartomas
Tumors of tissues NORMALLY found in that location
- nevus
- neurofibroma
- neurilemmoma = schwannoma
- glioma
- hemangioma
- lymphangioma
- CHHRPE
Where is a schwannoma on the eyelid usually?
Solitary nodule near medial canthus
List orbital choristomas
Tumors of tissues NOT normally found there
- dermoid
- dermatolipoma
- ectopic lacrimal gland
- complex conjunctival choristoma
There is a solitary nodular cyst at the lateral canthus. What is it?
Hydrocystoma
- either on lid margin or lateral canthus
- solitary nodular cyst
- lined by double row of cuboidal epithelium
5 causes of correctopia
Trauma Posterior synechiae (inflammation) ICE Axenfeld reiger Ectopia lentis et pupilae
Differential of congenital hypochromic iris
Wardenburg
Horner’s
Hirschprung
Parry Romberg hemifacial atrophy
Congenital unilateral hyperpigmented iris
Ocular or oculodermal melanocytosis
Iris pigment epithelial hamartoma
When do you see a Kayser Fleischer ring
Wilson’s disease
Chalcosis (foreign body)
Multiple myeloma
Lung carcinoma
What is the max dose of lidocaine you should use
5 mg/kg no epi , max dose 300 mg
7 mg/kg with epi, max 500 mg
DDx of intra-ocular calcium
Phthisis RB, retinocytoma ONH drusen Choroidal osteoma Choroidal hemangioma Retinal astrocytoma
