topography
Saving Patients from Themselves
Topography can help you persuade your contact lens patients to kick their bad habits.
BY JEFFRY D. GERSON, O.D., F.A.A.O., Overland Park, Kan.

Sometimes our contact lens patients need us to save them from themselves. Often, they don't even know that they need our help to save them from some disorder, or worse yet, from some habit they have. And that's where corneal topography enters the picture. Just think of those patients who abuse their contact lenses by overwearing them. To them, this doesn't seem like a problem, but we may be able to demonstrate otherwise. Here's one such case.

M.D.'s initial topography

Meet a contact lens abuser

M.D. is a 43-year-old male I recently examined. The only reason he came in to see me was because he couldn't obtain contact lenses. His prescription, which he received from our office, expired because he hadn't had an exam in more than a year and a half. I wasn't surprised to find that he'd been wearing his monthly lenses for four to five months, but I wasn't expecting him to tell me that he only took his lenses out once a month.

We discussed his overwearing practices, but he couldn't fathom that a contact lens could harm to an eye and said that he was likely to continue his habits. He felt that he was doing well. On the surface, this seemed true -- until I investigated further.

Investigating the situation

M.D.'s best corrected vision was 20/15- OD and 20/25- OS. His ocular motility, visual fields and tonometry were all within normal limits. The anterior segment exam was normal with the exception of conjunctival injection in both eyes, and an area of punctuate staining on his left corneal epithelium. His fundus exam was normal.

When I looked at his topography, however, I saw a different story. It showed an area of inferior steepening in his right eye and a large area of steepening and distortion in his left eye. This was likely the reason for the reduced acuity in his left eye.

Seeing the light

I spent some time showing M.D. his topography printout and explained that his contact lens wearing habits were likely the cause for his corneal changes. At that point, I could see that he was starting to believe that a contact lens could affect his eyes. He was willing to "do anything" to fix the situation -- as long as it didn't involve eyeglasses, taking his contact lenses out at night or frequent lens disposal.

These conditions may have been a problem in the past, but with today's silicone hydrogel lenses, they're a lot less of an obstacle. We know that findings such as the topographical ones mentioned above, along with infections, sterile infiltrates and other corneal changes, are more likely in extended wear of contact lenses. We also know that with the higher oxygen transfer coefficent (Dk/t) of silicone hydrogels, these problems are encountered less frequently.

Therefore I fit M.D. in a popular brand of continuous wear contact lenses. I explained that he could wear his lenses continuously for up to 30 days, but that he needed to dispose of them monthly. I asked him to return in approximately one month so I could monitor his corneal health.

M.D.'s follow-up topography

Checking up

At the follow-up visit I again performed topography. It was normal for both eyes, and the distortion and steepening had both resolved. M.D. was seeing a crisp 20/20 OU -- definitely an improvement in his left eye from when his corneas were distorted. He liked the new contact lenses and agreed to make the switch permanent.

M.D. even said that he was planning on removing the lenses monthly and coming back for his routine exam in a year (because his year supply of lenses would run out at that time).

Topography wins the battle

Because of the high Dk/t of the lenses I fit M.D. in, his corneas got enough oxygen to sustain their normal physiological functioning. I've seen this happen with a number of patients who've had similar findings, and similar success, with the silicone hydrogel material. Topography is a great way to demonstrate this return to normalcy with a hard copy of test results, rather than with theoretical explanations. I now perform topography on all contact lens patients and take the time to explain any changes in the findings to them.

Every time a patient comes in and tells me about her contact lens wearing habits, I still wonder if I will need to protect her from herself. Fortunately, with the help of my topographer, I can answer that question, along with others.

Topography, coupled with patient education, can really make a positive difference in the health and well being of your patients who wear contact lenses. Take my word for it.