7.1.1 Flashcards
What is hyperopia
Distance objects are clear and near objects are blurry. Light entering the eye focuses behind the retina instead of on it
What are side effects of a hyperopic px not wearing their gls
Strain
HAs
Accommodative issues
Blurred vision at near
Long adaption period when returning to visual aids
What are side effects of uncorrected amblyopia
Overuse of muscles
Amblyopic eye may not align properly with dominant eye under visual stress
Failure to suppress
Which near ADD for a 40-45yr old
+0.75-+1.00
Which near ADD for a 45-50yr old
+1.00-+1.50
Which near ADD for a 50-54yr old
+1.50-+2.00
Which ADD for 55-560yr old
+2.00-2.50
Which ADD for a 60+ yr old
+2.50 +
What does a patient with normal BV see during a fixation disparity test
Perfectly aligned target. This means visual axis of BE are correctly aligned for BV. No extra fusional vergence is needed.
How to know if a patients phoria is well compensated during the fix disp test
Px sees a normal image with both eyes open
What will a px with exophoria see on fix disp if phoria is not well compensated
The bottom vertical line has moved out to the right of the top vertical line
What will a px with esophoria see on fix disp test if the phoria is not well compensated.
The bottom vertical line moves to the left of the top vertical line
Why is fix disp testing carried out with both eyes open
If one eye is closed then Binoc fusion is distrupted
Which specific patients should you ask about to a px with eso/exo fix disp results that are not well compensated
Eye strain/fatigue
HAs
Blurred vision
How to prisms help with misalignments during fix disp testing
Reduce disparity and relieve stress
What prisms are used for exo and eso deviations
Horizontal
Exo = base in
ESO = base out
Adjust/increase prism till image is aligned
Which types of vision therapy is used to help uncompensated exo deviations
Stereogram / near point cards
Which types of vision therapy is used to help uncompensated eso deviations
Exercises focusing in DV / relaxing convergence
Is a Px sees half the chart on fix disp what does this mean
They are suppressing. The brain is compensating for the misalignment
When looking at vertically misaligned phorias how to know which eye has the hyper/hypo phoria
The eye that deviates the most up/down has the phoria
Which way are the eyes drifting in hyper and hypo phoria and how will this result on the fix disp chart
Hyper = eye drifts up wards so horizontal line will appear lower on the same side of the eye with the phoria(most deviation)
Hypo = eye drifts downwards so horizontal line will appear higher on the same side of the eye with phoria (most deviation
What will a px with esotropia see on fix disp test.
The top vertical line will move to the left of the bottom vertical line
What will a patient with exotropia see on fix disp test
The top vertical line will move to the right of the bottom vertical line
What long term issues can suppression cause
Loss of BV
Reduced depth perception
Amblyopia
Risk of DIP
When are convergence exercises and anti suppression exercises used
Convergence = mainly used for phorias. Help ability to converge/focus on near objects/maintain BV without strain or DIP
Anti suppression = mainly used for tropias. Aims to stop suppression and encourage binocular fusion.
Give 5 examples of convergence exercises
Pen to nose exercises
Brock string
Pencil push ups
Stereograms
Synaptophore
Give 4 examples of anti suppression exercises
Stereograms
Worth 4 dot
Fusion cards
Synaptophore
How to carry out pen to nose exercises and explain various results
Holding pen at arms length and bringing closer till becomes double. This point where becomes double , then stop moving it closer and move it back till it becomes single again. if keeps practicing will get closer to eye
Perfume 10x/2x per day
Normal result = 5-10cm from nose
Convergence insufficient = > 10cm
Excessive convergence = eyes converge too much 2-3cm from nose + symptoms
How to carry out brock string test
Hold one side of the string at your nose and the other tied up at eye level with 3 beads on the string. The furthest bead should be about 3m away from you. Focus on bead closest 30-40cm to u. U should only see one bead. Move string closer to u while focusing on the nearest bead. As it gets closer the string should form an X with the two eye images crossing at the bead. If you see 2 beads then ages are not converging properly
What are normal and abnormal results for brock string test and what do they mean
Normal result - string should form X shape pattern as 2 eyes focus on same bead
CI - as string comes closer px loses focus or DIP at further distance. 1 eye may drift out, string does not form X properly and px may see beads separately
CE - see DIP at very close distance 2-3cm from nose. Discomfort as eyes over converge. String may appear distorted.
What are the various results from pen to nose excercises and what do they mean
Normal - no DIp, NPC and 3-5cm
CI - DIP appears very early around 10cm from nose, eyestrain/HAs
CE - DIP may appear too close 2-3xm from nose, discomfort
Tropias - one eye drifts outward while other eye fixates on pencil
What is stereogram
Visual tool to help assess depth perception and improve BV. It helps to train stereopsis
How is stereogram carried out
Px sits 40-50cm from stereogram. Test may req special gls. Goal is to fuse 2 images and percieve 1 3D image. For px difficulty fusing they may see 2 flat images and need to adjust focus to bring 3D image into view. Can increase difficulty by making 3D image more complex. Or adjust the image to be slightly more seperated (challenges image to fuse images at diff depths)
What are the various results of stereogram test and what do they mean
Normal - able to see 3D image clearly
Inability to see 3D image - px sees 2 flat images with no depth - poor stereopsis indicated by amblyopia/strabismus/CI
If DIP seen - px has tropia or CI
How is synaptophore test carried out
Px sits 1m from machine. Test has 2 sep images depending on what test is being used for. For each eye the devise shows a sep image. If two identical image(testing fusion), different images(testing stereo), a target in 1 image(testing convergence), diff patterns/figures(testing suppression) px is asked to fuse images.
How is worths 4 dot test carried out.
Px is wearing red/green gls. A light or card is shown to Px with 4 dots. In the colours red/green/white/white. The colours help to isolate the input from each eye. They should report what they see as:
1 red dot seen by LE (through red filter)
1 green dot seen by RE (through green filter)
2 white dots visible in BE
What do the different responses mean in the worths 4 dot test
Normal - px sees all 4 dots which means good BV
Suppression - px sees 3 dots and suppressing from the weaker eye(misalignment)
DIP - px sees 5 dots, brain sees conflicting images from BE. Suggests strab/BV issues
How is fusion cards test carried out
Px wears red/green gls and is presented with a fusion card with 2 overlapping images/patterns each presented to a diff eye. Images are diff colours to help brain isolate each image to each eye. Px is shown card at reading distance and tries to fuse images I.e if 2 circles then should see 1 circle.
What is statistic retinoscopy
Measures refractive error when px accommodation is relaxed, the px looks at a distance target while light is shone in the eye to observe reflexes. Used to determine rx
What is dynamic ret
Carried out at near(40cm) to assess accommodative function. Observe reflex while px accommodates. If with movement - not accommodating enough , if against movement then over accommodating
What are a disadvantage of Binoc refraction
Some People don’t take it well and start to see DIP
