Interpreting Regular and Low Vision Eye Reports.
One of the things that is always a challenge is when you get information from a physician, an eye care professional, ophthalmologist, or an optometrist, interpreting the results of what you get. One of the things we want to do is look and see what kind of report it is, what kind of doctor it is, what the purpose is. The big challenge is there's a lot of jargon that's used. If you're not familiar with medical terminology, there are two resources I would highly recommend to you. The first one is a book by Cassin and Solomon called the Dictionary of Eye Terminology. It was originally published in 1929, but it has various updated editions. Easily found at amazon.com or anywhere on the Internet bookstores, you can order it. The other is a book by Vaughan and Asbury called General Ophthalmology. It's now under 'other authors,' but they're still expounding on the original book that they did. The most recent addition to that is in 2012. If you have a question about some specific eye conditions that are mentioned in the eye report and you're not sure what they are or what impact those are going to have, then that would be an excellent resource for you to look those things up.
I would recommend those two things if you are somebody who's going to be reading and interpreting eye reports on a regular basis. You're going to come across some terminology you're not familiar with. But what I'd like to do in this session that we have is to go through some of the major terminology that you'll hear, the different kinds of eye reports, what you might expect, and how it might look when you receive the results.
The first thing we're going to be talking about is a regular eye exam. Now, there are two different kinds. There's a regular eye exam-- it was actually three: regular eye exam, a low vision exam and a functional vision exam. We're going to be looking at the first two, a regular eye exam and a low vision exam.
The goal of a regular eye exam is to check the general health of the eye, look and see if there's any disease, any conditions that may impair vision, and to diagnose what those eye problems might be. The next thing, obviously, is to develop some kind of a treatment plan. The treatment plan might be getting glasses, might be having surgery, it might be medications for the eyes - something that's going to either address a disease of the eye or do something to improve your functional vision. Basically, what you want to do is to maximize vision using either traditional glasses, contact lenses, or sometimes LASIK surgery for people who don't have any eye diseases (that may just have a refraction error of some kind). Refraction is what we call the process of getting a good clear image on the retina, that then goes back to the brain where it's interpreted. If that's fuzzy or it's double vision or it's out of focus or has some distortion in it or something, you're going to be correcting that primarily through refraction.
What constitutes a regular eye exam? First of all, it can be done by either an ophthalmologist or an optometrist, and it may typically be done in what we call a SOAP format, S-O-A-P. This is something that's used in counselling too. It's just a procedural way to look at the various aspects of what happens during the exam. We'll break those letters down. The S is for subjective, the O is for objective, the A for assessment and the P for plan. Part of what you're looking at is why is the person here? What do they want to get out of the exam?
The first part is subjective. The best way to find that out is to ask the patient. What's going on? Where is your problem? Which eye? When did it start? Why did it start? Did you get hit in the head? Did you have an infection in your eye? Did you just have difficulty reading in certain situations or seeing in certain situations? Then often, they want to ask modifiers, adjectives. How difficult is it for you to see, in what kind of conditions, just to see if anything helps, like if you shine more light on what you're trying to see, does it work better? We do know that some of that is very much part of the natural aging process. The older we get, the more light we need to see something. So it may be that it's not even a refraction error, that it's just a matter of getting more light to the object that you're trying to see.
The subjective would go on then to look at their general medical health, any health history, have they-- for example, did they have a brain injury, did they have something that might impact their vision neurologically, had they had a stroke, what kind of medications does the person take? There are medications that have side effects. Some of those are prescription medicines and some are over-the-counter medicines, supplements and things like that.
To give an example of an older woman I knew, who was in her 80s, and she was starting to have a little trouble with her memory. She was taking vitamins that were specifically for improving your memory, some supplements specific for improving her memory, and all of a sudden she started having hemorrhages in her eyes. Part of what happened is that there was an increased blood flow to her head and that was manifesting itself with some hemorrhaging and bleeding in her eyes. So, it's very important that when you go for a regular eye exam that you take a list of what your medications are. Often, in an eye report, you'll see a list of what those medications are.
They want to ask about previous eye care, what other kinds of-- if you had any surgery in the past on your eyes, any situations that have come up that have required medical attention. Have you been wearing glasses since you were 10 and now you're 50, or what's the situation?
Then, this is always kind of interesting to me. They also ask a brief psychological. What they're asking here is what we call orienting times three. Are you oriented to the person, 'Do you know who I am?' the doctor will ask. 'Do you know where you are?' - orientation to place. And orientation to time, 'What day is it?' If it's an older person that's going in for exam and they're going to be billed through Medicare, they require that as a part of the exam. That may show up on your eye report, and you're thinking, Why are they doing this? That's because of the person's age and billing.
Then, after you've gone through the subjective and you have a general idea of what the person wants, then it's time for you to do some objective testing. The first thing that's usually looked at is visual acuity - sometimes referred to in a report as VA. It's not Veterans Administration or Veterans Affairs or Virginia, it's visual acuity. You'll see additional notation, sometimes s, a small letter s means without correction and a small letter c means with correction, and that correction would be either eye glasses or contact lenses - traditional types of correction. The visual acuity is also looked at both near and distance. They might be notated on your report as a DVA or an NVA for near and distant. Then, there'll be some reference to which eye. They'll be looking at the right eye, the left eye and both eyes together, but that's too easy to say that, so they use Latin terms. For the right eye, it's oculus dexter and they abbreviate that as OD. For the left eye, it's oculus sinister, abbreviated as OS. Then, oculus uterque means both eyes, which is notated as an OU.
Those three terms, you probably won't ever see the actual Latin on there, or will you see right or left most frequently form unless it's one that an agency that you work for prints up, but anything coming from the doctor's office is probably going to say OD, OS, or OU. Then sometimes, you'll see the terminology of BVA, that's for best-corrected visual acuity. They may do something, maybe you're 20/40 in your right eye, 20/60 in your left eye, together 20/40 because the dominant eye is the one that has the better vision. Then when they do some correction with glasses, you're 20/20 vision. That would be where you'd see those kind of things.
It will make a little bit of a difference on what kind of chart is being used. In charting visual acuity for social security purposes in terms of determining if somebody is legally blind, what's used is a Snellen chart. I'm sure you recall the definition of legal blindness, is vision of 20/200 in the better eye with best correction, or a restricted field of vision of 20 degrees or less. The first half of the vision requirement is visual acuity, and if a person's normal vision is 20/20 and a person sees 20/200, then their vision is much less and that 200 is based on the size of a letter. However, we often interpret that to mean the person sees at 200 feet what somebody with normal vision would see at 20 feet. It actually, though, it refers to the size of the letter, and that's done on a Snellen chart, S-N-E-L-L-E-N, Snellen, and that was developed way back, long before any of us were born. But sometimes to use the Snellen chart correctly - and that's the chart that has the big E on the top usually - it's going to be in a room that's 20 feet long. Most doctors' offices don't have that kind of space, so they may halve the space and they may report it as-- rather than using 20 feet, they'll say 10 feet. So they just divide it by two. Or sometimes, they use something called a Project-O-Chart. POC, so it might say POC, and many of you may have-- if you've had an eye exam recently, you go and you see a little TV screen and they have letters that are projected up into this TV screen and that's just another version of the Snellen reporting.
You can get more details on a Snellen chart, but in terms of social security, in terms of looking at whether or not the person is legally blind, it's on a Snellen or a Snellen-like chart that looks the same way. Now, the reason that's important is the big E on the Snellen chart is 20/200. The next line down has two letters on it, usually an F and a P, although there are some variations of the actual letters there, but that second one is 20/100. So if somebody's vision is 20/150, if they can't read the 20/100 line, they're considered to be legally blind because all they can read is the 20/200. That may explain why you see a lot of variation in the vision of people who are counted to be 20/200 legally blind. But nevertheless, that's the way it's reported. Now sometimes, you'll see for example 20/100-1. It means that they can read the 20/100 line minus one letter. You might see plus one. Maybe it's 20/70+1. That means he can read one letter on the next line correctly. That kind of gives you an idea of the Snellen chart.
Continuing on with the objective testing, the next thing they want to look at is how the pupils are reacting. If you recall, the pupil is that opening in your eye that's hidden behind your cornea that allows light to go in and hit the retina on the back of the eye. And the iris, which is the colored part of the eye, it works like an aperture. If there is a lot of light, it will close up a little bit, and if there is not so much light, it will open up to let more light in because the whole thing is about getting light waves to the retina so you can see. The testing that they will do for pupils, there's two different things that they'll do. One is to take a light and shine it directly into your eye and then move it away. What they're looking at is when the light moves into your eye, does the iris then cause a smaller opening in the pupil, and when they move it away, does the opening then get bigger? That's referred to as an afferent pupillary defect if that does not happen correctly. It will be a plus or a minus, having to do with whether the light comes in or the light moving away. It's also referred to sometimes as a Marcus Gunn pupil, and that's the name of the test to look at how that would be interpreted.
The other thing that they want to look at, are the pupils equally round and reactive to light and accommodation, and this is often referred to as PERRLA, P-E-R-R-L-A - Pupils Equally Round and Reactive to Light and Accommodation. And accommodation has to do with focusing near and distance, and also, it could have something to do with light and accommodation here. The doctor may say, 'Look at my nose, now look at my ear,' might shine a light in your eye, and they're checking out how those pupils are acting. If the pupils are not acting properly, that may give some indication of some kind of a neurological problem that may be causing the vision issues that somebody has.
The next thing they'll look at is EOM, extraocular muscles, and they're looking at the movement of the eye. We have six large muscles around the eyeball, one on top that moves the eye at an angle, one on the bottom that moves the eye at an angle and then four that move it straight back and forth and up and down. Those particular muscles, we want to make sure that the movement is smooth in both eyes, that both eyes are moving together. They might have you look into the upper right-hand corner and the upper left-hand, lower right, lower left. Often, they do it as a quadrant kind of report. Taking a look there and making sure that that movement is smooth and that there is no jerkiness in the way the eye moves. That again, would indicate maybe some type of neurological problem or if one eye moves much more readily than the other, it could be some kind of a problem with the muscle alignment, also referred to as strabismus.
Now, when we talk about eye alignment, if an eye turns constantly, it's called tropia. If it sometimes, but not all the time moves, it's called phoria. Then, if it's moving in towards the nose, it would be eso, and if it's moving out, away from the nose, it would be exo. Esotropia means that it's a constant turn in. Exophoria means that it's an intermittent turn outward.
Then, the next thing they'll be looking at are your visual fields, kind of a confrontation. Confrontation means that - not that they're having a fight - but they're looking right straight at you. Again, they'll do count my fingers in various quadrants - upper right, upper left, lower right, lower left. So, they'll hold up two fingers, one finger, or three fingers. Count my fingers, move the fingers, and they want you to be looking straight at their nose while they do that. They're looking to see if there is any really gross thing that theycan tell. They'll often have you do it with one eye occluded and the other eye occluded, and then with both eyes. Part of that is the brain is an amazing thing, it will fill in the blanks if you're not careful. Because it's seen the environment and you may look and you think you see something just fine, but actually, the brain has filled in the blanks. So when you count the fingers, you may be thinking you'll see just fine in the upper left quadrant, but in fact, he's only holding up one finger whereas in the previous quadrant, he was holding up two, or she. Therefore, you're missing out on what it is. In a report, that would be FTFC, full to finger counting in all quadrants, and they can give you some very gross general mapping of places where you might have blind spots.
Sometimes too, they'll use an Amsler grid, and I have a slide here that has an Amsler grid on it's-- it varies a little bit in how many squares there are, but it's basically a 10 by 10 grid most of the time. The lines are straight, and there's a dot in the middle. It's used a lot with people who have macular degeneration. They'll tell you to put it on your refrigerator and let me know if the lines change. And I have two diagrams, one where the lines are very straight, and the other one, there's a dark spot and the lines are a little bit twisted and kind of morphing into something a little bit different, making it look like there's a hole in the grid. That would show that there was some progression of the disease, in this case, macular degeneration that we're talking about and that allows a patient to be an active person in telling how things are progressing with their eye, with their vision, and that's something they would then report back to the doctor.
The other things they'll often do in looking at field, and the Amsler is more of a central, but it also does look a little bit at the field visions. The other thing would be automated fields, and the automated fields that you most frequently see is a machine called the Humphrey, the Dicon or the Octopus. They give a very detailed view of vision loss and can be used for either a central or a peripheral loss. Looking back to that in just a second, let me talk about some of the other kinds of objective tests and then we'll look a little bit more into those objective field things because I think that's where a lot of our confusion comes.