Ophthalmic exam Flashcards
What do you look at in hands off observation?
Facial/ocular symmetry Vertical height of the eye Angle of medial meniscus Distance from the medial meniscus to the centre of the pupil Anterior displacement/deviation Same colour
When in the examination would you perform the Schrimer Tear Test-1 (STT-1)?
Before use of light or any eyelid manipulation
How long should you leave the paper in the eye for an STT-1?
1 minute
How do you interpret the STT-1?
>15mm/min is normal but <10mm/min is low
Interpret in context e.g. one condition causing dry eye and one causing excess production could result in a normal reading
Compare both eyes and if drastically different then suspect underlying pathology
What are the different parts of the ophthalmoscope?
What anterior structures of the eye can you see in transillumintaion?
Details of the eyelid, conjunctiva and third eyelid
Cornea, iris and lens are transilluminable
What reflexes can you test with transillumination?
Dazzle reflex and PLR
What can you see whilst using the slit beam?
Contour and lesion depth
Surface contour of cornea, iris and anterior lens
Layers of the cornea to see ulcer depth and cataract localisaion in the lens
Quality of the aqueous humour in the anterior chamber
What changes can be seen in the anterior chamber?
Aqueous flare/Tyndal effect = swirling of keratic precipitates
Keratic precipitates once settled at ventral aspect of the eye
Hyphema and hypopion
Posterior/anterior synechia
Anterior lens luxation
Anterior presentation of the vitreous
What do you look at in distant direct ophthalmoscopy?
Tapetal reflection, pupil symmetry and use retroillumination
How do you illicit the tapetal reflection?
Lens at neutral setting up at your eye with animal at arms length and angle until the eyes reflect/shine back at you
What does senile iris atrophy look like?
Ragged edges of the pupil in old dogs
How do you differentiate between nuclear sclerosis and cataracts?
On retroillumination nuclear sclerosis is transparent but cataracts appear black
How do you perform close direct ophthalmoscopy?
<2 cm away from patient with your pupil, instrument and animals pupil aligned
Use right eye to right eye and left eye to left eye
Locate optic disc and divide into uaters then make a mental collage of the big picture
What happens if you scroll through the magnification of the lens?
Focus on different parts of the eye
The lens is +10-15
How do you perform indirect ophthalmoscopy?
Use ophthalmoscope by the eye not looking through it with a 300 lens infront of the animal’s eye
What image does indirect ophthalmoscopy give?
Inverted L to R virtual image with a larger field of view that is less magnified
What image can you see with a panoptic ophthalmoscope?
Same as indirect ophthalmoscopy but without the image being inverted
How do you perform fluoroscein staining?
Wet strip and drop dye onto the dorsal conjunctiva and in order to see if there are any ulcers rinse thoroughly and examine corneal surface under the blue light
What does the fluoroscein stain?
Stroma
What is a Jones Test?
Use fluoroscein but don’t rinse wait for a few minutes and see if stain flows out of nose and again use blue light
What is tonometry?
Tests eye pressure
Helps distinguish between glaucoma (high pressure) and uveitis (low pressure)
What is normal intra-ocular pressure?
12-22mmHg
What is conioscopy and what does it measure?
Specialists tool that looks at the iridocorneal angle
