right so you're in the clinic, you have some vitreous floaters, sudden onset of floaters in
your vision. It looks as though the optometrist is just checking your pupil sizes there
just do it in each eye, looking for an anisocoria before reviewing the back of the eyes
it's important to do some pre-checks before dilating
the pupils and having a good look at the fundi
so it looks as though the optometrist is now checking pupil reactions to light
doing the direct
and consensual, followed by a swinging flashlight test looking for a relative
afferent pupillary defect. It may be present or partially present a retinal detachment
and the lights' coming from the lateral side. It may be that the optometrist
is checking the openness of the anterior chamber
ensuring it's safe to dilate the pupils
looking at that shadow cast on the iris from the light on the lateral sides there
and I would assume the optometrist is going to check intraocular pressures before dilating
having a little look if the pressures are okay
so he's using a minimum anaesthetic combined with fluorescein dye and he's just going to
set up the Perkins tonometer there checking the dial, the headrests. Now with Perkins you have
to numb the eye because the probe touches the cornea just very delicately for a few seconds
looks through the viewing portal, aligns the mires accordingly and then reads off the scale
to determine what the pressures are at that particular moment of the day
and next up
and next up it looks as thoug we have the ophthalmoscope, now the
optometrist may be checking for any corneal staining
using the cobalt blue light there, just to see if there's been any corneal staining
following contact tonometry, it's a very good practice there
now
the next step for the optometrist should be to dilate the pupils
so let's have a look. So we have another minim here
so I'd assume we're going to use Tropicamide
one in the right eye, one in the left. You can visualize the floaters just a little bit more
with a lighter background there
It may be if the optometrist wants to achieve
best possible dilation, he could opt for a second drop of Phenylephrine 2.5%
one drop in each, lower the lid, pop the drop at the bottom, the patient has a few blinks
and it looks as though the optometrist is just pinching the nasal bridge there
so the idea of this is to just block the drainage canal, the canaliculi
for the eyes to try and absorb as much of the drops as possible
so after about 20 to 30 minutes we should have a maximum possible dilation
so the optometrist is now setting up the head mounted binocular indirect ophthalmoscope there
this is the method
that is going to be used to review the back of the eyes.
So now we can look for any retinal tears or detachment
So we have
the light source. We have to adjust the distance between the
two viewing portals. We want a nice binocular view, some good stereopsis
Okay the optometrists will just be holding the high-powered lens in front of the eye
Just looking good to all the quadrants of the retina through a dilated pupil
We
have a good field of view with dilation and this method for checking the back of the eyes
probably the most common way to do this would be using the slit lamp and a Volk lens but this is
a good alternative method if there's no slip lamp
so the optometrist will be getting the patient to look
in eight positions of gaze: up, down, left, right
and the diagonal areas
really looking as far out as possible
to see whether these vitreous floaters
have come about from a tear or detachment
It could just be that the patient hasn't had
anything sinister occur. The patient could have had a posterior vitreous detachment
It would probably be likely the patient would be experiencing some kind of flashing lights
in their vision along with the floaters
We should also investigate whether the patient has experienced any physical trauma to the head
that may have led to these floaters
so now he's using the red free light
this
allows the blood vessels to be visualized a little bit better
giving them a black appearance against the retina
switching between the eyes there
Okay so the patient will be looking up there
and you can still see the vitreous floaters is moving there
if it is a PVD the patient's experienced then it's important to reassure the patient
and obviously to come back to the clinic if their symptoms worsen or if they develop
any other symptoms associated with a retinal detachment or tear
so now we're onto the cobalt blue
Just having another look there
switching between the eyes
Now if something
sinister like a tear or retinal detachment was detected,
the optometrist has to make a referral to the eye hospital
for ophthalmology attention quite sharpish
So it looks as though test, the BIO test is completed
Okay now sometimes you can better visualize floaters using the
direct ophthalmoscope up close there, again asking the patient to look the eight directions of guys
both eyes, right and left
just to really get an idea of the amount, and size of floaters that have appeared
Okay, just going out as far as you can
And asking the patient to look as far out as possible
okay that's everything