pediatric and teen cl care

Predicting Lens Wear Success

BY JEFFREY J. WALLINE, OD, PHD, & MARJORIE J. RAH, OD, PHD

Efficiency is very important for a successful contact lens practice. One way to improve efficiency would be to fit only those patients who have a higher chance of successfully adapting to lens wear. Over a minimum time period of two years, you can expect 8- to 14-year-old children to adapt to GP lenses approximately 55 percent of the time (Walline et al, 2004), corneal reshaping lenses about 75 percent of the time (Cho et al, 2005), and soft contact lenses more than 90 percent of the time (Walline et al, 2009).

Because the adaptation rate for soft lenses is so great, screening children for potential soft lens adaptation is not necessary. However, screening corneal reshaping and GP candidates for potential adaptation may be beneficial.

Traits of Non-Adapters

Most children who are not able to adapt to contact lens wear stop wearing lenses within the first few weeks (Walline, 2009). A run-in period prior to a GP contact lens myopia control study (Walline, 2003) helped us understand more about the children least likely to adapt to contact lens wear. It was thought that boys, younger children, children who had less myopia, children who reported more irritation with lens wear, and children who had difficulty handling contact lenses would be less successful. However, there were no differences between the adapters and non-adapters when it came to gender, amount of myopia, or contact lens irritation.

Children not able to adapt were younger, had more against-the-rule astigmatism, and wore their lenses less often. However, the children in the study all had <1.00DC of refractive astigmatism. It is unknown whether the non-adapters wore their lenses less and so they couldn't adapt, or they couldn't adapt, which made them wear their lenses less.

Anecdotally speaking from experience with fitting children with GP lenses, children who don't even like you to touch the adnexa during the slit lamp examination are less likely to succeed.

Parents are also a considerable factor. A parent who is involved without being overbearing is the best indicator for success. If the parent answers every question you ask the child, or if the parent is too occupied to discuss contact lenses and to watch the child during the training session, then the child is less likely to succeed.

If the child has extremely small palpebral apertures or extremely poor dexterity, then adaptation is less likely. Some pediatric contact lens fitters assess children's hygiene. If the child has trimmed fingernails or reports brushing teeth regularly, then the child is more likely to be able to handle the responsibility of lens wear.

Your First Impression Matters

In a study of 8- to 17-year-old patients fitted with soft lenses, practitioners were asked to report how difficult they thought the fitting process would be based on first impressions of the subject. As it turns out, the practitioners were very good at predicting the amount of chair time that would be required to fit the children with contact lenses (Walline et al, 2007). The indicators of success most often cited were the parents' enthusiasm as well as the children's motivation, hygiene, aperture size, and willingness to have drops placed in the eye.

While the practitioners were good at predicting the amount of chair time, unfortunately there are no strong indicators of a child's ultimate success with contact lens wear. So, try fitting any child with contact lenses as long as you feel comfortable that the child has a reasonable chance of success. Typically you won't "waste" much chair time because those who cannot adapt quit wearing contact lenses almost immediately, and many times children surprise you with their ability to adapt. CLS

For references, please visit www.clspectrum.com/references.asp and click on document #168.

Dr. Walline is an assistant professor at The Ohio State University College of Optometry, where he conducts studies of pediatric contact lens wear. He is also a consultant or advisor and has received research funds from Paragon and Vistakon. Dr. Rah is a staff optometrist at the Massachusetts Eye and Ear Infirmary Contact Lens Service where she specializes in medically necessary and other advanced contact lens designs.