pediatric and teen cl care
Fitting Infants and Young Children With GP Lenses
BY CHRISTINE W. SINDT, OD, FAAO
Many practitioners dislike fitting GP contact lenses on infants and small children because keratometry values are not easily obtainable. The keratometry values will vary depending on the number of weeks of fetal gestation and the eye pathology involved.
Premature infants will have steeper corneal curvatures that decrease rapidly after birth, reaching the normal childhood range within 12 weeks (Friling et al, 2004). Smaller eyes, such as those that have persistent hyperplastic primary vitreous, will also have steeper corneas.
A rapid change in corneal curvature occurs in the first few weeks of life, slowing significantly after eight weeks of life. Table 1 shows the predicted keratometric curves suggested in the literature (Shin et al, 1999). The first fit change is expected at 6 to 8 weeks of age, with the next around 6 months of age. Base curves are often stable at 9 to 12 months old.
GP Lens Fitting on Young Children
The best way to fit GP lenses on children is to simply put a lens on the eye and then adjust the fit according to the fluorescein pattern. Figure 1 shows examples of steep, flat, and on-K fluorescein patterns. I've found that a five-LED cobalt blue flashlight by Inova (Emmisive Energy Corp) provides the brightest illumination—brighter than the slit lamp—and it is portable, which can make pediatric contact lens fitting much easier. CLS
Figure 1a. Example of an on-K fluorescein pattern.
Figure 1b. Examples of fluorescein patterns of progressively steeper and flatter fits.
For references, please visit www.clspectrum.com/references.asp and click on document #170.
Dr. Sindt is a clinical associate professor of ophthalmology and director of the contact lens service at the University of Iowa Department of Ophthalmology and Visual Sciences. She is also the chair-elect of the AOA Contact Lens and Cornea Section. She is a consultant or advisor to Alcon, Ciba Vision, and Vistakon and has received research funds from Alcon.