Sensory Adaptations Flashcards
what do you need for the development of bsv
clear visual axes
for the two eyes to be aligned
that’s why fundus and media check is done to check if retina can recieve image
need to ensure nothing is disrupting visual pathway , so that image can get to the visual cortex
what happens in the Brain if bsv develops
if we have bsv visual information is bing transmitted along the visual pathway
we want messages to get to the visual cortex
we want oral develop of ocular dominance columns
we want binocular connections
what would happen if infantile et was ‘‘untreated’’
they may have amblyopia and they may alternate
they may develop suppression
can a patient with infantile et achieve bsv
]to give them a chance of bsv evidence suggests that we have to intervene with surgery early on
even if eyes are aligned we know that bsv will not be normal good quality bsv it will be gross bsv
what would you expect the clinical scenario to be in early onset strabismus e.g. pt had some period of time where eyes were straight and then had early onset strabismus and then had surgery in adulthood and some evidence of bsv
this is suggestive of having some period of time where there eyes are aligned before they had strabismus
therefore important to take proper history to determine when they had surgery and when squint started and were the eyes are straight for a period of time
tells you weather bsv is able to be restored or weather they never had any bsv to begin with
what would happen if cataract reminded untreated (e.g. unilateral infantile catract had remained untreated)
this would cause poor va in that eye due to stimulus deprivation amblyopia - occlusion treatment would typically done to treat this simulus deepirvtion amblyopia
could a patient with a unilateral cataract achieve bsv
if you treated in early and quickly then there is a chance of treating the amblyopia - they could develop bsv but not normal bsv because they have had amblyopia - they have had a difference in the two eyes - e.g. aniesmetropia and possibly refractive correction oof there eye - so there have had a lot that prevents the development of their visual system - so ma be able to develop bsv but at a a reduced level
what is likely to happen if a child has amblyopia at a very young age
- they may also have a suppression aswell which is when the suppression will be affected - so visual acuity and strabismus should also be monitored - they may develop Esotropia secondary to visual loss
if an older child has infantile cataract what happens
e.g. L unilateral cataract ‘‘mild
small angle secondary LXT
occlusion treatment
NO BSV
Child age 7
would you correct L refractive error
this patient has suppression
there may be times where we are correcting refractive error even though the child has a strabismus because the monocular temporal area is giving them useful information
when would you expect :
normal correspondence
abnormal correspondence
normal correspondence —
fovea of one eye corresponds to the fovea of another eye and the retinas correspond - the nasal retina of one eye corresponds to the temporal retina of another eye
abnormal correspondence
sensory adaptation where the fovea of one eye corresponds to a point thats not the fovea of another eye (pseduofovea)
when they are just using on eye they are using there anatomical fovea but when they have Both eyes open - then the fovea of there straight eye will correspond with a point other then there anatomical fovea and all of the corresponding retinal ;points change to allow the patient to use there pseudo fovea
what are example of abnormal correspondence
microtropias
are there any other types of correspondence
you can have no correspondence between the two eyes
what happens in incongruous diplopia
they get diplopia but I dosnt correspond to the angle of the deviation
what is paradoxical diplopia
they get diplopia but it is on the side opposite the side of the deviation
ee.g. they might have homonymous diplopia in a exotropia or heteronomous diplopia in a esotropia
