The Hill of Sorrow: Understanding the symptom curve in the treatment of dry eye
“No pain, no gain” is a lousy philosophy in physical fitness, and it is particularly difficult to sell it in any medical setting. Yet this is exactly what we must do when we are treating the most severe cases of dry eye.
I am on record as stating that the single most important metric in the treatment of dry eye syndrome (DES) is patient symptoms. Indeed, this is a major flash point between ophthalmologists in the community and our academic brethren. Once trained to identify the clinical signs of any disease, it is nearly impossible to resist the temptation to treat them, even in the absence of symptoms. “You can’t make an asymptomatic patient feel better” is an apt motto for our DES world, as I have noted.
The problem with this, as with all dogma in medicine and elsewhere, is that exceptions exist for every hard and fast rule. While it is true that the majority of DES patients will have at least one symptom that you can measure and treat, there is a stage at which the damage done to the cornea by DES is so severe that the corneal sensory nerves cease to function. At this point, your patient may quite accurately tell you that she feels well, thank you very much, despite a cornea that looks like frosted glass at the slit lamp.
I like to think of the symptom curve of DES as the “Hill of Sorrow,” both for my patient and myself.
The Hill of Sorrow
Draw a simple graph. The X axis is disease severity, and the Y axis is symptom severity. Draw a smooth line that looks a bit like a stretched out bell curve, with a similar slope on the upward and downward sides and a “soft” plateau on top.
The left side of your graph is intuitive: It makes sense that symptoms will generally get worse as the underlying disease itself worsens. A supermajority of your DES patients are somewhere on this upward slope, and treating them is equally intuitive.
On the upward slope of the curve, your treatment aggression is proportional to your patients’ symptoms and signs, and the likelihood that they will adhere to the program is proportional to their symptoms at any given time. No sorrow here. Every little bit of movement to the left of the curve brings happiness to both doctor and patient. As I have written before, the challenge will be getting your patients to stay on the regimen that will keep them symptom-free. Still, all in all, the left side of the symptom curve is all rainbows and unicorns.
Once we crest the top of our symptom curve, we begin to suffer. Both parties, patient and doctor. As the severity of the DES increases and the health of the corneal sensory nerves becomes compromised, patients actually begin to feel better. If you are seeing folks at this stage on their initial visit, you may actually have a hard time convincing them that they need any treatment at all. Remember, even though it may not apply on the doctor side of the equation, symptoms are still, and always, the most important metric for the patient. Impressing upon them the need for treatment can be quite a challenge.
Take a look at your graph for a moment, and think about what you are about to do. You have before you a patient with a severe dry eye, with clinical signs that just cannot be ignored. A treatment is prescribed that will hopefully effect a dramatic decrease in the severity of the DES, and you successfully convince your patient to begin therapy. A steady march to the left of the curve ensues.
How many times have you and your staff fielded a phone call from a DES patient complaining that your treatment made him feel worse? Some of these phone calls are understandable, for example — a new Restasis (cyclosporine ophthalmic emulsion 0.05%, Allergan) patient complaining of a little burning sensation — but some do not seem to make any sense at all. You started a patient with severe superficial punctate keratitis and a tear osmolarity of 360 mOsm/L on a topical steroid and Blink (Abbott Medical Optics), and she calls 3 days later telling you that she feels worse. That the Blink causes searing pain. Seriously? Blink?
You and your patient are now climbing the Hill of Sorrow.
This is actually just as intuitive as anything you see on the other side of the curve. As the severity of the DES decreases, the corneal sensory nerves are awakened, and now your patient is able to feel her dryness. Being a patient-centered physician, you, of course, bring the patient to the office to rule out anything that might have arisen to threaten the health of your patient, but what you see is that your treatment worked. The cornea looks better.
For me, this is the most difficult part of caring for the dry eye patient. It is terribly difficult to help a patient understand that she is already better despite the fact that she feels worse. In my experience, this is much more difficult than keeping a previously symptomatic patient on chronic therapy once her symptoms have abated. Indeed, this aspect of DES as a progressive inflammatory disease that can actually reach a point where your successful treatment seemingly hurts your patient is reason enough to insist on beginning therapy on the left side of the symptom curve for every DES patient.
Once you have crested its peak, it is a hard climb back to the top of the Hill of Sorrow.
For more information:Darrell E. White, MD, can be reached at SkyVision Centers, 2237 Crocker Road, Suite 100, Westlake, OH 44145; email: firstname.lastname@example.org.
Disclosure: White is a consultant for Bausch + Lomb, Allergan, Nicox, Shire and Eyemaginations. He is on the speakers board for Bausch + Lomb and Allergan.