Battling Postsurgical Dry Eye
Battling Postsurgical Dry Eye
Specific diagnosis and comprehensive treatment are key to comfort and clarity.
By Karl G. Stonecipher, MD
In 9 out of 10 cases, I meet my refractive surgery patients on the day of surgery. Most patients with dry eye issues are screened before they see me, and I use a screening process to identify and begin preoperative treatment on anyone who slides in under the radar. But after surgery, some patients still suffer from surgically induced dry eye.
In refractive surgery, as well as cataract surgery, I'm cutting the corneal nerves by making the flap. Patients are losing that feedback mechanism, and the tear film is no longer sufficient. The nerves take 4 to 6 months to return to normal. So when a patient comes in for follow-up and says, "I paid all this money, but I can't see very well. My vision is fluctuating," that patient isn't telling me his surgery didn't work. He's telling me his eyes are dry.
The goal is to restore a healthy tear film. To achieve this, I need to make an accurate and specific diagnosis, and it's imperative that I choose the right treatment.
Lissamine Green Staining
Tear film and tear volume are valuable metrics, but using lissamine green is the easiest way to diagnose dry eye. You wet the strip, put it in, look at the eyes, see that they've got a little stain and say, "Miss Johnson, you've got dry eye." The process is very simple.
If the patient has meibomian gland disease, you'll see more staining patterns, including inferior staining and broad streaks. Tear break-up time is low because the lipid layer is disrupted. Patients with aqueous deficiency show a more localized, circular tear break-up over the dry spots, as well as diffuse circular tear break-up.
Patients with exposure problems from blinking or sleeping with their eyes open have all types of exposure patterns. Of course, you need to ask whether anyone has ever told them that they sleep with their eyes open, since that's the only way to find out if this is an issue.
I think it's important to evaluate staining using a grading system. I use a pattern with scores of 0 to 3 for each of five ocular zones. The temporal and nasal zones are used to diagnose with lissamine green stain, and the corneal stain is in line with fluorescein.
|Changing the Dynamic|
|I work with 294 different referring optometrists, and more and more of them are diagnosing and treating dry eye. Some are even advertising as "dry eye specialists." As a surgeon, I think this has the potential to improve my throughput, and I'm certain it can help your practice as well.|
My advice is to get information to and from every patient. Ask all of your patients to complete a dry eye questionnaire. It keeps their problem from slipping through the cracks, and it gives you a clear reference point to say, "According to your background and symptoms, you have mild [or moderate or severe] dry eye." Patients understand that.
In addition, because dry eye treatment may require reappointment, you have time to expand your patients' knowledge by showing them videos or directing them to educational Web sites. When they return, they'll know more about their condition, which will help reduce chair time.
When a refractive patient has postsurgical dry eye, there are many options. We often use plugs diagnostically. We find that 90-day extended-duration plugs work best for us, because we can put them in and send the patient back to the referring physician, who can make a diagnosis based on the plugs' effects.
We also suggest supplements for everyone. When we began using Omega 3 supplements more heavily in our practice, we found they really help stabilize the tear film.
For patients with signs of lid margin disease, my first choice is azithromycin (AzaSite, Inspire Pharmaceuticals Inc.) because it has some anti-inflammatory, as well as antibiotic, properties. Its DuraSite (InSite Vision Inc.) delivery system allows it to stay on the lid margins. Doxycycline is also effective and is very inexpensive. But never forget that routine lid scrubs are effective, as well.
Artificial tears are essential for postsurgical dry eye, but I prefer Oasis Tears for patients with chronic dry eye. My colleagues and I began evaluating different visco-adaptive products, such as Oasis, a few years ago. Oasis is different than your natural tear, and it's much more effective for patients, because it stays on the eye much longer than other tears.
The effects are measurable. Oasis Tears have long chains that thicken the tear film. In some studies, 83% of patients increased their tear break-up time by about 50%, which means they saw better for longer periods of time and didn't need to use drops as frequently.1
The glycerin in Oasis Tears is an osmotic, so it helps clear vision upon instillation. However, I also think the hyaluronan is key, and viscoadaptive drops, such as Oasis, help patients see better after they use the drops. When patients use Oasis Tears, their vision clears immediately. There's no waiting, as required with some thicker drops. Patients say they experience better comfort, and we see lower enhancement rates, and that's what it's all about.
Dr. Stonecipher is director of laser and refractive surgery at The Laser Center in Greensboro, N.C.
|1. Data on file. Oasis Medical, 2008.|
Optometric Management, Issue: December 2008