Key points 22 Flashcards
Which imaging modality is MOST likely to be beneficial in assessing activity of thyroid eye disease?
STIR sequence MRI
Which gas injected intravitreally would last longest?
In order of longest to shortest: C3F8 > C2F6 > SF6 > air
What is the choice of treatment option in choroidal melanomas?
Brachytherapy is the most appropriate treatment to preserve as much useful vision as possible, which is an important consideration in this case as visual acuity is still very good at 6/9.
Tumours of up to 5mm thick can be treated with ruthenium plaque and up to 10mm with iodine plaque.
Iris atrophy in herpes simplex uveitis tends to be:
Segmental iris atrophy is more characteristic of herpes zoster (caused by a segmental iris vasculitis). With herpes simplex, patchy iris atrophy near the pupillary margin is more common.
The most common cause of retinal re-detachment after an initially successful clinical course in scleral buckling for rhegmatogenous retinal detachment is:
Proliferative vitreoretinopathy (PVR) is the most common cause of late failure after scleral buckling. Overall, open breaks (usually missed at the time of surgery) are the most common cause of failure in buckles, but with open breaks the failure occurs early (typically the retina never re-attaches after the operation). If the clinical course post-op is initially good and failure occurs later, this is usually caused by PVR. PVR can, of course, occur at any time after RRD, and may already be present before any surgical correction has been attempted. When PVR is present pre-operatively, the success rate of RRD surgery is lower.
The characteristic posterior segment tumour of von Hippel-Lindau disease is:
Retinal capillary haemangioma associated with Von Hippel Lindau
A patient with bilateral optic disc pits presents with gradual deterioration of vision in the right eye. On examination, the vision is right eye LogMAR 0.3, left eye LogMAR 0. An OCT confirms schisis at the fovea with sub-retinal fluid on the right and normal imaging on the left.
What would be your initial treatment?
Less-invasive treatments like laser photocoagulation should be tried initially for optic disc pit maculopathy, followed by a combination of vitrectomy and internal gas tamponade if symptoms persist.
What are the 5 peaks on A scan?
corneal surface
lens anterior surface
lens posterior surface
ILM of the retina
sclera
The fourth cranial nerve nucleus resides in:
The fourth cranial nerve nucleus resides in the midbrain.
The association of neurofibroma with congenital glaucoma is strongest with lesions of the:
Upper lid neurofibromas, especially plexiform neurofibromas (shown above), are most closely related to the development of glaucoma in patients with NF-1.
Fluorescein angiography in punctate inner choroidopathy (PIC) typically shows:
Fluorescein angiography of PIC lesions typically shows early hyperfluorescence in the arterial phase and late staining (reference). In some cases, the lesions can block fluorescence in the early arterial phase (hypofluorescent) and stain thereafter (reference). There are typically more lesions on FFA than are apparent clinically. CNV develops in up to 40% of cases and FA is particularly useful for detecting these changes. Treatment of CNV involves anti-VEGF therapy, argon laser or PDT. Prognosis in PIC is guarded and dependent largely on the degree of sub-foveal involvement by the initial PIC lesions, and by the subsequent development of CNV.
What is the cumulative risk of glaucoma at 5 years in eyes with pseudoexfoliation?
Different studies have reported different rates. However, the cumulative risk of glaucoma in eyes with PXF is considered about 5% at 5 years and 15%-30% at 10-15 years.
What is the average age of diagnosis of neuroblastoma
2 years old
Which landmark clinical trial demonstrated that one third of eyes with minimally classic or occult choroidal neovascularisation treated with ranibizumab gained over 15 letters from baseline to 12 months?
ANCHOR and MARINA were the two earliest landmark studies supporting the use of ranibizumab. The ANCHOR trial looked at predominantly classic choroidal neovascularisation while the MARINA trial looked at minimally classic or occult choroidal neovascularisation.
What should be avoided as they have anti-platelet activity and can increase the risk of a re-bleed in traumatic hyphaema?
oral ibuprofen
A baby has just received transpupillary diode laser in theatre. Based on the UK Retinopathy of Prematurity Guideline 2008, what is the next recommended action?
examine 5-7 days post-treatment
Bilateral superior oblique tenotomies for correction of an A-pattern exotropia, can be expected to cause how much of an esodeviation in downgaze?
A bilateral superior oblique tenotomy causes approximately 40 prism dioptres of esodeviation in downgaze (to correct an A pattern). The procedure has little eso effect in primary gaze and none in upgaze.
Superior oblique overaction is MOST likely to be encountered in
The superior oblique muscles are abductors, particularly in downgaze. Thus, overaction will result in overabduction (exotropia) in downgaze (A pattern).
Some practitioners do not recommend the full hyperopic correction in intermittent accommodative esotropia because:
Correction with full hyperopic prescription may weaken the patient’s fusional divergence, which is the force keeping accommodative esotropia intermittent at its outset. Then, the esotropia may become constant without the crutch of the spectacles.
Which agent should be used with caution in a patient with narrow angles?
Acetazolamide and the sulphonamide derivatives have been described as precipitating on rare occasions an idiosyncratic reaction with raised IOP due to anterior rotation of the ciliary body with malignant glaucoma and shallowing of the anterior chamber. Acetazolamide is nonetheless used in intractable narrow-angle glaucoma, but awareness of this reaction is important. The alpha-2 agonists such as brimonidine and apraclonidine cause a mid-miosis in normal eyes, and therefore are not a risk for precipitating an acute angle closure attack. Apraclonidine only causes mydriasis in the context of Horner’s syndrome but not a non-Horner’s eye.
What percentage of optic nerve axons may be lost before visual field changes are detected by Goldmann perimetry?
Pathological changes of the optic nerve precede visual field changes. In fact, up to 50% of optic nerve axons can be lost before any change is detected on the Goldmann visual field. This observation has stimulated interest in measuring the retinal nerve fiber layer thickness via computer using technologies such as the OCT. These technologies will likely be useful but will never replace the need for a careful ophthalmoscopic exam and clinical assessment.
What are the features of the autosomal dominant form of CHED?
progressive and presents between 1 and 2 years of age with photophobia and tearing. Nystagmus is usually absent. The autosomal recessive form is present since birth and stationary. A sensory nystagmus is more commonly associated with the recessive form because vision is poor since birth. This disease must be differentiated from congenital glaucoma, which may present with buphthalmos and enlarged corneal diameters.
Which condition is most likely to be associated with enophthalmos from orbital fat absorption:
Leber’s congenital amaurosis carries a very poor visual prognosis, with an extinguished ERG. Fundi may be initially normal but changes such as chorioretinal atrophy, pigmentary retinopathy and macular coloboma-like atrophy are common. Oculodigital syndrome may occur, in which constant rubbing of the eyes by the child causes enophthalmos as a result of resorption of orbital fat.
A negative angle kappa simulates:
A negative angle kappa is much less common than a positive angle and may be caused by high myopia. With a negative angle kappa the eye appears esotropic.
A positive angle kappa simulates:
With a large positive angle kappa (e.g. dragged macula temporally) the eye appears exotropic as the eye is tilted more temporally to focus light on the fovea.
