from EBOD Flashcards
actions of superior oblique
The primary action of the superior oblique muscle is intorsion, the secondary is depression and the tertiary is abduction
superior oblique - angle with visual axis
51º
Lockwood’s ligament
The pulleys of the inferior oblique and inferior rectus muscles join to form Lockwood’s ligament
recession of the inferior rectus muscle can lead to
lower eyelid retraction with widening of the palpebral fissure
resection of the inferior rectus muscle can lead to
lower eyelid advancement with fissure narrowing
A person with anomalous retinal correspondence does not have binocular vision - T or F
F
Motor fusion
vergence movement
Sensory fusion
based on the innate topographic relationship between retina and visual cortex, whereby corresponding retinal points project onto the same part of the cortex
Pathological suppression and ARC cannot develop in adulthood - T or F
T
Amblyopia is responsible for more cases of unilateral visual impairment of childhood onset than all other causes combined - T or F
T
The most common form of amblyopia is
strabismic
In ametropic amblyopia there is a bilateral reduction of visual acuity - T or F
T
Part-time occlusion, defined as occlusion for 2-6 hours a day, can achieve the same results as full-time occlusion - T or F
T
Part-time occlusion - how many hours
2-6 hours a day
in moderate to severe deficits - how many hours of patching
at least 6 hours a day is preferred
Pharmacological penalization is as effective as the use of patches to treat severe amblyopia - T or F
F (Pharmacological penalization is as effective a treatment as the use of patches for mild to moderate amblyopia)
In children at the preverbal stage (0-2 years), visual acuity can be detected by
fixation behaviour (CSM method), VEP, preferential looking or the “fix-and-follow” method
In a 6-year-old child, the most reliable test is
Snellen letter or number charts
In a 2-5-year-old child, the most reliable test is
Snellen E chart together with HOTV optotypes, LEA symbols and Allen figures
monofixation syndrome
form of subnormal binocular vision without bifixation characterized by small-angle strabismus, unilateral absolute facultative central suppression scotoma of less than 3º, and peripheral fusion. there is peripheral fusion with the absence of bimacular fusion due to a physiological macular scotoma
Monofixation Syndrome - causes
Surgically corrected strabismus (most common), Anisometropia, Macular lesion, Primary
Monofixation Syndrome - Worth test
In the Worth test, at a distance of 3 m, the lights are projected onto the central area of the retina, so patients will see two or three lights, and as the lights get closer to the patient, they start to be projected onto the peripheral retina. Having passed the central scotoma, the patient may fuse and see 4 Worth lights.
Esotropia - crossed or uncrossed diplopia
Uncrossed (homonymous)
Exotropia - crossed or uncrossed diplopia
Crossed (heteronymous)
red glass test - normal retinal correspondence
the measured distance between the two images is equal to the previously measured deviation
red glass test - anomalous retinal correspondence
the patient saw two lights, but the separation between them was less than that measured previously
Accommodative esotropia - AC/A and fusion
hyperopia and/or a high AC/A ratio associated with insufficient fusional divergence
Accommodative esotropia - time of onset
between 2 and 4 years of age
Accommodative esotropia - treatment
The first therapeutic step is optical correction of hyperopia. If the child continues deviating at near after several months despite optical correction, even if he or she does not present esotropia at distance, bifocal glasses graduated for near vision will be prescribed. Surgery is reserved for cases where there continues to be notable esotropia at distance despite good optical correction with glasses.
Accommodative esotropia - patching occlusions ?
NO! only when amblyopia
