Key points 12 Flashcards
What are features of NF1
axillary freckles, prominent corneal nerves and absence of the greater wing of sphenoid. Lisch nodules, ectropion uveae and occasionally iris mammillations.
Hydropic swelling of lens fibres is most consistent with what kind of cataract
Cortical
What is the 2 stage procedure in Baerveldt implant?
During the first operation, the scleral plate is sutured to the globe without connecting the tube into the anterior chamber. This procedure is followed by a second operation 2 to 8 weeks later, during which the tube is inserted into the anterior chamber.
Which peripheral retinal lesions is the most common in the population?
microcystic degeneration
When do the majority of flap folds occur after laser-assisted in situ keratomileusis (LASIK)?
More than 50% of flap folds occur within the first day, and over 90% occur within the first week post-operatively. Not all folds need to be repaired, but visually significant folds should be repaired within 24 hours.
Where does the 6th CN originate from?
arises in the lower pons from a group of cells situated in the floor of the fourth ventricle.
A patient is orthophoric in primary position with normal vertical eye movements. On attempted right gaze, both eyes fail to move from primary position. Left gaze is normal.
Where is the lesion?
The sixth nerve nucleus contains both sixth nerve axons and interneurons destined for the contralateral medial rectus sub-nucleus via the medial longitudinal fasciculus. Thus, a lesion of the sixth nerve nucleus can produce an ipsilateral gaze palsy. Left paramedian pontine reticular formation damage would result in a left gaze palsy. Damage to both medial longitudinal fasciculi would cause a bilateral internuclear ophthalmoplegia. A lesion of the right sixth nerve fascicle would produce a right abduction deficit.
What conditions is Fuchs uveitis associated with?
rubella, CMV and herpes simplex.
What are the features of Duane 1 syndrome?
limited abduction with or without esotropia (most common 85%)
What are the features of Duane 2 syndrome?
limited adduction with or without exotropia
What are the features of Duane 3 syndrome?
similar limitation of abduction and adduction and any form of strabismus
What are the features of Duane’s retraction syndrome (DRS):
unilateral or bilateral abnormality of horizontal gaze
caused by co-contraction of medial and lateral recti
retraction of the globe on attempted adduction
upshooting or downshooting of the globe on adduction
the left eye is affected more frequently than the right
females are affected more frequently than males
Type 1: abduction limitation greater than adduction, eso (most common)
Type 2: adduction limitation greater than abduction, exo (least common)
Type 3: abduction and adduction limited equally
amblyopia in 10%
What are the indications for heavy tamponade in VR surgery?
penetrating injury detachment
giant retinal tear
posterior break detachment
choroidal detachment
extensive tractional detachment
re-detachments
proliferative vitreoretinopathy
Which finding in a patient with bilateral granulomatous uveitis establishes the diagnosis of Vogt-Koyanagi-Harada (VKH) syndrome, rather than sympathetic ophthalmia (SO)?
the chronic diffuse granulomatous uveitis involves the choriocapillaris, whereas in SO this layer is spared. Obviously, the two diseases overlap considerably. SO must be considered in patients with a history of previous eye surgery.
What do Pathologic specimens of Fuchs uveitis show?
The inflammatory nature of Fuch’s cyclitis is supported by the presence of plasma cells and lymphocytes on pathologic examination of ocular tissue.
How much convergence does 1 PD of accommodation cause?
The normal AC:A ratio is 3-5, meaning that 1 dioptre of accommodation causes 3-5 prism dioptres of convergence.
When is medial recti surgery preferred over lateral recti in squint surgery?
For deviation greater at near, surgery is recommended on the medial recti, while for deviations greater in the distance, surgery is recommended on the lateral recti.
Which is the MOST benign form of scleritis?
diffuse anterior scleritis
Which conditions is APMPPE linked to?
TB
anti-hepatitis B vaccination
mumps
Wegener’s granulomatosis
polyarteritis nodosa
ulcerative colitis
sarcoidosis
Lyme disease
What is positive angle kappa?
represents a slight temporal position of the fovea relative to the optical axis. This causes a slight temporal rotation of the globe to keep the image on the fovea. This, in turn, causes the corneal light reflex to be displaced nasally. The deviated light reflex remains stable with cover testing as the fovea never spontaneously moves relative to the optical axis.
What are the classic findings in POHS?
peripapillary pigmentation and or atrophy
punched-out chorioretinal scars in periphery
linear chorioretinal scars
A patient presenting with multiple evanescent white dot syndrome (MEWDS) is most likely to report
shimmering photopsias and paracentral scotomas.
What are the features of MIDAS syndrome
microphthalmia
dermal aplasia
sclerocornea
The angle of minimum deviation of a prism occurs when:
the angle of incidence equals the angle of emergence
