Diagnostic contact lens fitting of the child patient from ten (10) through seventeen (17) years of age is probably one of the most rewarding in a clinician’s daily practice life. I have tried a few things over the years and I hope that these might help you.
Rarely do children have large palpebral aperture size nor are their lids loose. On the contrary, their apertures are small and the lids tight; these two make insertion of a diagnostic contact lens difficult at times.
When you do see a small aperture size, consider a 14.0 lens or smaller as a first fit trial lens. Because of the small apertures, success in inserting the lens the first time is essential to retain confidence in the process. I have found that parents and patient alike will continue the lens fitting process if the doctor or the assistant can insert the lens on the first try.
Often the child will prefer not to wear glasses at all, even to the point of removing the glasses when they are out of sight of parents, family members or teachers. Although this should be a strong motivation to try contact lenses, the fear factor is concomitantly high and the process of diagnostic contact lenses can quickly extinguish the drive for contacts. Of course, if the child wears eye makeup, the child may overcome this fear.
A good starting point is a lens of 14.0 mm in diameter. A larger lens, even 0.2mm larger, may be too large. Although not ideal for an adult, a spherical lens that approximates the spherical equivalent may provide sufficient and satisfactory vision for a child. Such vision may be adequate and sufficient for average school activities. As facility with lens handling improves, then a larger toric lens may be contemplated.
For rigid lenses, the diagnostic fitting should be as comfortable as possible and I do apply a single drop of surface anesthesia to minimize lens sensation at the outset. There are quite a few of my peers who might find this unacceptable, but I have found that this dramatically improves rigid lens acceptance. In addition, the lack of excessive tearing makes the lens movement that much better to assess and refract over. Depending upon the goal of the rigid lens fit, I will start with an 8.6 diameter lens. Frequently this covers the cornea sufficiently while still providing satisfactory comfort, fit, movement and lens flexure.
Children who are short in stature may find difficulty in positioning themselves within a biomicroscope. The even when the chair is raised at its highest point, the child’s eyes might not be high enough. In those cases, a bundled rubber block that is wrapped in plastic may give the additional one inch that elevates the eyes high enough for slit lamp use. Of course, a handheld slit lamp would be much preferred.
Dispensing the lens at the end of that first visit is key to continue the momentum and enthusiasm for lenses. If the patient cannot demonstrate facility with lens removal and insert, then a follow up will be needed. I don’t usually see patients coming back more than twice for training in lens handling.
In summary, children make good contact lens patients. Frequently, just asking the patient what they know about contact lenses can spark an interest that is underlying but not mentioned. In general, parents support their children in wearing contact lenses. The doctor and staff can easily support that interest by introducing the topic and providing an immediate forum for beliefs and concerns that parent and child may have. Don’t miss an opportunity by not talking about it.