How is dry eye diagnosed?

Back when I first started doing advocacy work in dry eye, it often felt like the patient had to become an expert before they walked in the door if they were to have any hope of coming away with an accurate, meaningful, well-articulated diagnosis.

Remember those days when the chances were relatively high that your symptoms would be totally dismissed on the strength of a sloppily administered Schirmer test (with no anaesthetic) and absent signs of surface damage? When dry eye was dry eye, and nobody seemed to know what a meibomian gland was or why they should care?

I'm so thankful for all the huge strides that so many optometry and ophthalmology practices have made since then in diagnosing the finicky details of dry eye and, just as importantly, in communicating those details to patients. But I believe that while these improvements to the standard of care have penetrated well into specialty practices, they haven't necessarily trickled down all that much to mainstream eyecare practices yet. It's certainly gotten much harder to pass yourself off a dry eye specialist on the basis of fitting plugs and prescribing drugs, which is great, but from the new patient's perspective, the reality of seeing multiple eye doctors before getting meaningful diagnosis is very much still there.

There's a multiplicity of good informational sites explaining what tests might be performed, so I won't spend time on those right now. (I don't actually believe in micro-managing this part anyway; I think it's more important to get yourself in the hands of the right kind of doctor.)

Instead, there are two areas I want to delve into today:

First, what IS a diagnosis?

In my personal opinion, "dry eye" is NOT a diagnosis.

Dry eye is a misnomer. It's a catchall. It encompasses all kinds of things. It does not accurately describe what the majority of people who supposedly have dry eye really have. It's too broad a label.

Imagine going to a cardiologist because of periodic chest discomfort. After a battery of tests, the specialist diagnoses you with "heart trouble" and shooes you out the door with a prescription or two. Really? "Heart trouble" is informative only in the sense that it identifies the organ affected. It tells you nothing about what's wrong or how the drugs might help.

So with "dry eye". It narrows things down to the tear system, which is necessary, of course, but if it doesn't go any further than that, it doesn't tell you what you most need to know, which is what's actually wrong and why — the vital context for understanding your treatment options. 

When I talk to someone who says their diagnosis is "dry eye", and even after probing has no more information to offer, I find they tend to fall into one of these two categories:

The truly "shallow" diagnosis

By "shallow" I mean with evidently no meaningful attempt to figure out what's actually wrong with the tear film. Are you not producing enough tears? Or are your meibomian (oil) glands chronically clogged, so your tears are just evaporating super fast? Are there other factors in play like eyelid closure issues? Nope... we just look at you through the slit lamp, maybe put a little dye in, and make a pronouncement.

The potential harm to the patient in these situations is that they spin their wheels for far too long on generic treatments that were never likely to help in their circumstances, and/or they do not get the treatments that ARE likely to help, because the specific problem hasn't been pinpointed. Again, the classic scenario is having the dryness treated as a tear production problem when it's really an oil problem. But there are other scenarios of diagnoses not going deep enough, to the patient's detriment, as well.

Then there's....

The correct diagnosis that the patient doesn't learn

I think that these days, many people are diagnosed pretty well, but the details just aren't communicated effectively. (Not that I take it for granted that it's a lapse on the part of the doctor — some patients just aren't paying attention and don't care — but honestly, if they're having enough trouble that they're talking to people they never met, like me, about it, chances are they're reasonably well motivated to learn what's wrong.) I think of people I speak with who, based on what they are able to share about their treatment history, clearly have been in the hands of a doctor who diagnosed some very specific things going on with their lids, but who really don't have an understanding of what's going on. 

The potential I would see for harm to the patient here is that when they don't know or understand their diagnosis, they're less motivated to be compliant, especially with instructions that are a nuisance. They're also more likely to be anxious.

Second, what is "mild", "moderate" or "severe" dry eye?

Here's the really touchy part of the diagnostic process: assigning severity levels. The classic scenario is when you are in real pain, or not sleeping at night, or not able to do really important activities, and the doctor says it's really not that bad, and honestly believes s/he is giving you good news. It's the perfect setup for mutual frustration. You end up trying to voice how much worse you feel than they think, and they end up thinking you are over-dramatizing things.

It's important to be looking at both symptoms and clinical signs individually when talking about severity. It is well known that these two things frequently do not correlate well, and yet that fact is frequently lost in practice in these appointments and conversations.

Your doctor determines the clinical severity of what you have, based on the tests they've performed of your tear production, meibomian gland condition, tear film osmolarity, signs of inflammation and so on.

But when it comes to symptoms, you may need to be the one to have to find a way to quantify symptom severity, unless your doctor is using some kind of symptom survey each time you have an appointment. Never rely on narrative alone for conveying symptoms. Numbers are almost always more effective when talking to your eye doctor. If your doctor doesn't have a tool to offer, use the OSDI questionnaire. Get the app for your phone if you can - it has the added benefit that you can track your symptoms over time and eventually may even be able to rate how well a treatment or combination of treatments is helping. Symptom severity is vital context for making decisions about steps you take to treat and manage dry eye.

In my ideal world, an appointment with the eye doctor about dry eye would always end with a discussion of how the clinical side and the symptom side relate (or don't), along with a discussion of strategies to manage symptoms and the expected timeline to symptom benefits from any medical treatments. Meantime, though, we can always take the initiative to get those conversations started and nurse them along.