Key Points 3 Flashcards
What percentage of patients with Bell’s palsy will experience complete spontaneous recovery?
Approximately 85% of patients with Bell’s palsy spontaneously recover, although some will have a degree of aberrant regeneration. Recovery usually begins within 3 weeks of diagnosis and usually becomes complete by 2 to 3 months.
Features of Mittendorf Dot
Mittendorf’s dot is a remnant of the posterior tunica vasculosa lentis. It is a white dot typically located on the infero-nasal posterior lens capsule. It is visually innocuous.
Which cataract can be found in a patient with deafness and haemorrhagic nephritis?
The clinical features suggest Alport’s syndrome, which is associated with anterior lenticonus and anterior polar cataracts
A patient presents with blepharospasm, irritated eyes and gradual reduced vision. On examination, you discover conjunctivitis, keratitis, polychromatic cataracts and disc swelling. You suspect this presentation is related to the patient’s background endocrine abnormality.
What is the most likely diagnosis?
hypoparathyroidism
Ocular features of Hypocalcemia?
conjunctivitis
keratitis
polychromatic cataracts
papilloedema
CSF values can range from normal to markedly elevated
Which of the following complications of filtration surgery is more likely with an inferiorly-placed bleb?
Endophthalmitis is more common with inferiorly-placed blebs, probably due to the pooling of infectious agents in the tear film inferiorly.
Ocular associations of CSCR
optic disc pits, optic disc coloboma or choroidal tumours
In which conditions can Supranuclear vertical gaze abnormalities can be a feature of?
pineal region tumors
ataxia-telangiectasia
Parkinson’s disease
Parinaud’s syndromoe
What is the ratio of cones to ganglion cells in the fovea?
The ratio of cones to ganglion cells is 1:1 in the fovea.
What is the ratio of rods to ganglion cells in the periphery?
10,000:1
A 41-year-old lady underwent penetrating keratoplasty 8 weeks ago for keratoconus. She has new-onset mild photophobia but her vision remains better than pre-op. She has marked mydriasis despite not taking any mydriatics since surgery.
The Urrets-Zavalia syndrome is the presence of persistent post-operative mydriasis after penetrating keratoplasty. The cause is uncertain, but it is thought to be due to peri-operative iris ischaemia.
What are the Ocular side effects of apraclonidine
eyelid retraction
mydriasis
conjunctival blanching
Why is IOL insertion avoided during cataract surgery in JIA patients?
the risk of aggressive postoperative inflammation, which can be further aggravated by an IOL. Cycitic membranes can ensue, with hypotony and phthisis.
What structures pass within the common tendinuous ring?
The oculomotor nerve (superior and inferior divisions), abducens nerve, nasociliary nerve, sympathetic root of the ciliary ganglion and on occasion the inferior ophthalmic vein.
Which is the most appropriate visual acuity test for a healthy 3-month-old baby:
Less than 1 year, forced preferential looking cards such as Keeler are most appropriate.
Which is the most appropriate visual acuity test for a healthy 1-2 year old child?
Between 1-year-old to 2-year-old Cardiff acuity cards are suitable.
Which is the most appropriate visual acuity test for a healthy 2 year old child?
Kay pictures are used for children with sufficient language skills to name the pictures (usually age 2).
Which is the most appropriate visual acuity test for a healthy 3 year old and older child?
Sheridan-Gardner or alternatives such as the Sonksen (cards each containing a single letter or crowded letters) are useful for children age 3 or older.
What is dysplasia?
associated with increased cell number and nuclear abnormalities such as hyperchromasia (increased cell staining with haematoxylin) and pleomorphism (altered nuclear size and nuclear shape).
What is Uhthoff’s phenomenon?
the decrease in vision with an increase in body temperature
Systemic Features of hyperparathyroidism?
systemic
fatigue
renal stones
polyuria
bone pain
peptic ulcers
Ocular Features of hyperparathyroidism?
ocular
band keratopathy
conjunctival calcification
corneal opacification
Which drug is most likely to cause binasal field defects?
Vigabatrin is a selective inhibitor of GABA-transaminase, and is used as a second- or third-line anti-epileptic. In rare instances, it can cause an idiosyncratic (rather than dose-related) optic neuropathy. Central vision remains unaffected, but signs include:
optic nerve pallor
RNFL atrophy
concentric peripheral field loss with temporal and macular sparing (bi-nasal field defects)
Which of the following observations is very sensitive to extreme scores in a distribution?
The mean is the average value of observations, and therefore very sensitive to extreme values in a distribution.
A fluorescein angiogram demonstrates occlusion of a large choroidal vessel producing a wedge-shaped hypofluorescent area.
What is the diagnosis?
Occlusion of choroidal vessels (to produce a wedge shaped hypofluorescent area) can be caused by:
malignant hypertension
lupus choroidopathy
renal disease
What features are characteristic of latent nystagmus
bilateral
becomes manifest when one eye occluded, blurred or intermittently suppressed
jerk-type nystagmus
null point in adduction
fast phase towards fixing eye
face turn towards the fixing eye as this dampens nystagmus
associated with interruptions to binocular development: congenital esotropia, but also monocular congenital cataracts
What features are characteristic of congenital nystagmus:
jerk or pendular nystagmus
normal or near-normal visual acuity
no change in nystagmus with unilateral occlusion or blurring
fast phase switches: to right in right-gaze, to left in left-gaze
null point can occur in any position of gaze
compensatory head postures vary by patient: face-turns either way or chin up, chin down depending on the position of the null point
titubation
tends to dampen with convergence, darkness, sleep, when eye is covered
increases with fixation
paradoxical OKN response
What is Wolfram Syndrome?
also known as DIDMOAD = diabetes insipidus, diabetes mellitus, optic atrophy and deafness. Inheritance is autosomal recessive, presentation is between 5-21 years and visual prognosis is poor with severe optic atrophy. Systemic abnormalities include anosmia, ataxia, seizures, mental handicap, short stature, and endocrine abnormalities.
What are ocular signs of POHS?
absence of intraocular inflammation, atrophic histo spots in the mid-periphery and posterior pole which may become pigmented at the margins, peripapillary atrophy, risk of CNVM, increased prevalence of HLA-B7 and HLA-DR2
In patients with HIV, cytomegalovirus (CMV) retinitis usually occurs with CD4 counts:
Less than 50 cells/mm3.
What are the strongest and weakest orbital walls?
The lateral wall is the strongest while the anterior portion of the medial wall (the lamina papyracea) is paper thin and the weakest.
OCT findings in solar retinopathy
characteristic focal disturbance at the fovea of the inner-segment-outer-segment junction
How does Ciprofloxacin work?
Ciprofloxacin is a fluoroquinolone antibiotic. It inhibits bacterial DNA synthesis by its action on bacterial DNA gyrase. It is effective against many species of Pseudomonas, Staphylococcus and Haemophilus.
A 36-year-old lady attends clinic complaining of headache and transient visual obscuration. On examination, there is bilateral disc oedema.
What should be your next step?
measurement of blood pressure
The most common risk factor for the development of preseptal cellulitis is:
Minor skin trauma is the most common risk factor for the development of preseptal cellulitis. The most common causative agent is Staphylococcus aureus.
The most common risk factor for the development of orbital cellulitis is:
Sinusitis is the most common risk factor for orbital cellulitis.
Which channels do Local anaesthetics work on?
inhibit voltage-gated sodium channels, preventing initiation of an action potential
What are associated with blepharophimosis syndrome
blepharophimosis
blepharoptosis
epicanthus inversus
telecanthus
ectropion in some cases
euryblepharon in some cases
Hypertelorism vs Telecanthus
hypertelorism implies an abnormally wide distance between medial orbital walls. Telecanthus is an abnormally wide distance between medial canthi, though the interpupillary distance may be normal. Telecanthus may be isolated (primary) or secondary to hypertelorism.
What phase do Chromosomes replicate during
S phase as the cell prepares for mitosis
What is Refsum syndrome
an inborn error of metabolism due to a deficiency in the enzyme phyctanic acid 2-hydroxylase, resulting in the accumulation of phytanic acid. It causes pigmentary retinopathy, polyneuropathy, cerebellar ataxia, deafness, anosmia, cardiomyopathy and ichthyosis. Treatment is with plasmapheresis and later with a phytanic acid-free diet.
What are some Ocular side-effects of topiramate
blurred vision
myopia
suprachoroidal effusion
angle-closure glaucoma
scleritis
Features of Benedikt syndrome
ipsilateral CN III palsy
contralateral cerebellar ataxia with intention tremor
contralateral hemiparesis (usually partial) with hyperactive tendon reflexes
Features of Claude syndrome
ipsilateral 3rd nerve palsy
contralateral cerebellar ataxia
Features of Weber syndrome
ipsilateral 3rd nerve
contralateral hemi-paresis
Features of Nothnagel syndrome
ipsilateral 3rd nerve
ipsilateral cerebellar ataxia
Ocular side effects of Fabry disease
vortex keratopathy
cataract
retinal vessel tortuosity
The most common cause of posterior uveitis in the adult population is
toxoplasmosis
A Pancoast tumor is MOST likely to cause a what order Horners?
Pancoast tumor at the apex of the lung is in close proximity to the location at which the sympathetics exit the spinal column and would cause a second-order Horner’s.
Which treatment is most appropriate for acute dacryocystitis
Acute dacryocystitis is treated with systemic antibiotics and warm compresses. Probing the system does not successfully treat the problem in adults. If a lacrimal sac abscess forms, then incision and drainage may be necessary.
What is an important step in Paediatric cataract surgery?
Paediatric patients have a high incidence of aggressive posterior capsular opacification, so many surgeons advocate primary posterior capsulotomy and even anterior vitrectomy to remove the hyaloid face at the time of cataract extraction
The key clinical feature distinguishing a nevus flammeus from a capillary hemangioma is:
Capillary hemangiomata will blanch with pressure, whereas the nevus flammeus does not
Which part of brain strokes are responsible for failure of ipsilateral pursuit?
Parietal lobe lesions cause failure of ipsilateral pursuit
What are the OKN findings in a left parietal lobe stroke?
poor OKN response when the drum is rotated towards the side of the lesion
A patient with an upper lid basal cell carcinoma has the lateral half of the upper lid removed and the lateral canthal tendons excised.
Which is the most suitable surgical technique for lid reconstruction?
a lateral periosteal flap provides a good anchor for repair of the upper tarsus where the lateral canthal tendon has been excised. A free posterior lamellar graft will not provide adequate support.
What conditions are typically associated with increased pigmentation of the trabecular meshwork
pseudoexfoliation
pigment dispersion
previous inflammation or surgery
uveal melanoma
What is the 30 minute patch test for XT evaluation?
With this dissociating patch on for 30 minutes, the near deviation often increases and approximates the distance deviation. This deviation would then be classified as a pseudo-divergence excess. Using a + 3.00 D lens may also prove helpful to look for high AC/A ratio patients. This classification is important both for determining how far to recess the recti muscles and for prognosis.
Which mediator of acute inflammation is derived from cells?
cytokines
histamine
leukotriene
Where does the image formed by an object outside the centre of curvature of a concave mirror lie:
between the centre of curvature and the principle focus
Give some clinical features consistent with (Type 1) classic galactosaemia
lethargy, vomiting and diarrhoea. Reducing substances are found in the urine. oil droplet cataract
When does the choroidal phase occur in FA
occurs after 8-12 seconds of dye injection
What is Ocular melanocytosis
a congenital blue naevus of the episclera and is most common in whites. When ocular melanocytosis occurs in combination with periocular cutaneous melanosis (nevus of Ota), it is termed oculodermal melanocytosis
Epidermoid vs Dermoid cysts
Both dermoid and epidermoid cysts are ectoderm-lined inclusion cysts. Epidermoids have only squamous epithelium; while dermoids contain hair, sebaceous and sweat glands, and squamous epithelium. The most common location of a childhood orbital dermoid is the supero-temporal orbital rim. The variety that is silent until adulthood is generally intraorbital (retroseptal).
Characteristics of SLK?
superior limbal hyperaemia
mild keratitis
superior palpebral conjunctival papillary reaction
micropannus
filaments
rose bengal or lissamine green are useful dyes to show affected conjunctiva
may be associated with thyroid dysfunction
Treatment: 0.5% to 1.0% silver nitrate solution, pressure patching, mechanical scraping, conjunctival resection, or bandage contact lens
A patient suffers from left exotropia which is causing diplopia. On the cover test, when the left eye is covered:
the right eye will stay stationary and subjectively the image on the right will disappear
What is the Reese-Ellsworth classification
The Reese-Ellsworth classification was developed in the 1950s as a guide for predicting visual prognosis in eyes treated by methods other than enucleation. It has been used erroneously to predict patient prognosis for life.
Which mutation is seen in Retinoblastoma?
mutation in the long arm of chromosome 13 (13q14)
A 3-year-old presents with periocular ecchymosis, sub-conjunctival haemorrhage and proptosis. There is no history of trauma. The CT scan shows a mass within the lateral orbital wall. There is no bone erosion.
What is the most likely diagnosis?
Neuroblastoma is characterised by the following:
most common extracranial solid tumour in children
originates from: adrenals, mediastinum, and neck
20% exhibit orbital involvement
most frequent orbital metastasis in children
mean age of presentation of orbital neuroblastoma metastases: 2 years
orbital symptoms: proptosis and periorbital ecchymosis (raccoon eyes)
prognosis generally poor but better if it presents under 1 year of age
spontaneous regression of this tumor may be seen in rare instances
What are ghost KP’s
Ghost KPs can occur in chronic anterior uveitis, and these are remnants of previous mutton-fat KPs
ARN vs PORN in terms of which part of the retina is first involved?
ARN typically involves the peripheral retina first, with the posterior pole spared until late in the disease. This is in contrast to PORN, which occurs in immunocompromised patients and involves the posterior pole early.
A 36-year-old lady who was in a car accident several days ago complains of vertical diplopia since the accident. On examination, she has a right hypertropia worse on left gaze and improved by left tilt.
What would you use to measure the amount of torsion that this patient has?
The Maddox rod takes a point source of light and converts it into a straight line. With a Maddox rod in front of each eye (in a trial frame), the patient can rotate one of the rods until the lines he sees in each eye are parallel. The difference in the axes of the two Maddox rods is the degree of torsion.
Types of indirect gonioscopic lenses
large scleral-type lenses (e.g. Goldmann 3-mirror) and smaller, corneal-type lenses (e.g. Posner, Zeiss, Sussman).
Types of direct gonioscopic lenses
Koeppe, Richardson, Barkan, Wurst and Swan-Jacob lenses.
Ocular features of Marfan syndrome
associated with hypoplasia of the dilator pupillae which renders mydriasis difficult. Angle anomalies are present in 75% of eyes, characterised by dense iris processes and thickened trabecular sheets, which may be responsible for glaucoma.
How to treat post trabeculectomy bleb failure?
ocular compression
suture manipulation
bleb needlng
subconjunctival 5-FU injection
bleb revision
