Key points 2 Flashcards
What is the maximum advisable resection of MR and LR in esotropia
medial recession: 6 mm
lateral resection: 9 mm
What is the maximum advisable resection of MR and LR in exotropia
medial resection: 10 mm
lateral recession: 10 mm
What are the features of myogenic congenital ptosis?
dysgenesis of the levator muscle complex
the levator complex is atrophic with replacement of muscle fibers by fibrous or adipose tissue
How to treat uveal effusion syndrome?
placement of partial thickness scleral windows near the vortex vein exit sites in at least three quadrants of the eye.
differential diagnosis for posterior ischemic optic neuropathy (PION)
radiation optic neuropathy
status post-coronary artery bypass graft
anaemia
acute systemic hypotension
giant cell arteritis
Features of malignant hypertension
produces posterior segment features such as AV nipping, exudates and haemorrhages
What is incomplete penetrance
In an autosomal dominant (AD) condition, gene carriers may sometimes have few or no signs of the disorder
What is variable expression
The degree or extent to which a disorder manifests in an affected individual
Ultrasound features of a sinus mucocoele with orbital extension
a rounded extraconal lesion with well-defined, smooth borders and very low internal reflectivity.
Ultrasound features of Neurofibromas in the orbit
Well-defined with smooth borders but will have high reflectivity.
Ultrasound features of Lymphangioma in the orbit
irregular borders
Ultrasound features of Metastatic cancer and pseudotumour in the orbit
have irregular borders and high reflectivity.
characteristic features of early-onset (infantile) exotropia
presentation at birth or soon thereafter
normal refraction
large angle
DVD
neurological anomalies frequently present (unlike infantile eso)
Rx: mainly surgery, e.g. LR recess/MR resect
Culture medium for Chlamydia trachomitis
McCoy agar
Facts about the use of topical beta blockers
IOP reduction is better in combination with prostaglandins than CA-inhibitors
they act primarily by reducing aqueous secretion
their IOP-lowering effect is less during sleep
Features of Miller Fisher syndrome
ophthalmoplegia
areflexia
ataxia
Antibodies seen in Miller Fisher syndrome
anti-GQ1b IgG antibodies.
Examples of conditions with Mitochondrial mutation implications?
Leber’s hereditary optic atrophy (LHON) - painless subacute visual loss, with central field defects, abnormal colour vision and optic atrophy
MELAS (mitochondrial encephalomyopathy, lactic acidosis, and stroke like episodes)
Kearns-Sayre syndrome (KSS)
MERRF (myoclonic epilepsy with ragged red fibres)
MIDD (maternally inherited diabetes mellitus and deafness)
Positive antibodies in MG
anti-muscle-specific receptor tyrosine kinase antibodies
anti-acetycholine receptor antibodies
anti-striated muscle antibodies
Positive antibodies in Lambert Eaton syndrome
anti-calcium-channel antibodies
Features of Mooren’s ulcer
ulceration of the peripheral cornea
circumferential spread and later may spread centrally
undermined leading edge
conjunctival injection
pain may be severe and accompanied by photophobia
autoimmune process likely: immunoglobulin, complement, and plasma cells in conjunctiva
Which part of the brain controls the slow pursuit component?
the parieto-occipital lobe
Which part of the brain controls the saccadic component?
Frontal lobe
Which clinical features of newly diagnosed idiopathic pars planitis is most predictive of the future development of multiple sclerosis (MS)?
The risk of future multiple sclerosis (MS) following a diagnosis of pars planitis exceeds 16%. The risk in studies is greater among patients presenting with retinal vascular sheathing.