Hey there, one of the most common questions I'm asked is how to measure accommodative lag. This is a really important measurement for myopia management because it can give us an idea of how much risk there is of a child progressing and also what tool we're going to prescribe, whether we're going to get a good result with contact lenses or whether spectacles are sometimes better depending on what's happening with binocular vision. So on the Myopia Profile website there's a lot of how-to guides and there is a how-to guide on how to measure accommodative lag but it's always easy to see things in video so I thought I thought I'd show you this today. Now the most essential tools to measure accommodative lag are some flippers.
Here I've got plus minus 0.50 out to plus minus two. And the way I mark them to make them easy to see is I put circles around the plus side and little minuses on the minus side. So easy to flip and see what you're doing.
And of course your RET, your most beloved RET. Hopefully you love your RET as much as I do. So the easy thing about accommodative lag measurement is that when you do retinoscopy, whatever results you get is the new RET result. You don't have to do any working distance correction. It is important when you do it, if we imagine we've got a patient just here in front of us, that you don't rep at your normal distance because we don't read at that distance, do we?
We read at a close distance. So we do need to make sure that we're at an appropriate distance, 33 to 40 centimetres to take these measurements. Now when you're using the flippers, it's very easy for you to just slide the flippers down over the top of the patient's eyes and then quickly flip.
And I quite often hold two or three flippers in. in my hand at once. Four's a bit much for my small hands.
But you can quickly flip between the three flippers and get very quick measurements. So what I'm doing here is I'm flicking between plus 0.50 and plus one. You can very quickly with your ret just scan across and have a look at the reflex.
Now we want to pop it over both eyes at the same time so they have the same accommodative demand. And when you flick between the two, if you're getting, say for example we're getting with with the plus 0.50, then we get against with the plus The answer is plus 0.75, easy. So we need to make sure that we've properly corrected distance vision before we do near retinoscopy so you know what the absolute lag is in comparison to their distance refraction. And think of this like the near refraction. So we're very concerned about distance refraction, but our near refraction is just as important and maybe even more so when we think about what children and young adults are doing all day long.
They spend so much time looking up close. So if you get a greater lag, you've got stronger flippers you can use. and I also use these flippers for my distance retinoscopy because it's with starting with my plus 150 because it's very very easy to switch between the two of them so we'll just show you how this is done and if you grab yourself some flippers and grab your trusty rep which if you haven't picked up for a long time you should pick up because it's an amazingly useful tool then you'll be measuring accommodative lag super quickly we'll show you how it's done now I do also need to mention the target so you can get these near cards to stick on your rep for children children or adults to look at, or if you've got a younger child, you can also get these targets with images.
And this makes sure that we have an accommodative lock, a proper target, and you tend to get lower results that way because a patient's actually got something to look at. It more simulates what happens in real life with reading. So let's pop one of these targets on.
And I have the wonderful Razia here who's learning me her eyeballs to show you how it's done. I've got my flippers. Now make sure, remember when we're doing Nearet, that we don't do it at our normal retinoscopy distance with my arms all the way up. out straight we need to be in nice and close at a reading distance so I'll get you to work look at the word look there and all you need to do is hold the flippers over both eyes just swipe the beam horizontally and vertically you can do both eyes at the same time switch between the flippers you can switch between all of them and even add them together to be able to get to the right power we've got our distance vision perfectly corrected and remember whatever your answer is that's your new retinoscopy result that's your accommodative lag so you can see it it's really simple and easy to do so give it a try yourself get yourself some flippers and you're it and you'll find it super easy