Article Date: 5/1/2003

orthokeratology today
Corneal Reshaping in Children
BY MARJORIE J. RAH, OD, PHD

Many previous and ongoing studies have evaluated the effects of gas permeable (GP) contact lenses on myopia progression in children. The results of these studies vary, but many believe that GP contact lenses slow myopia progression. Lately, a common question I have been asked is what effect overnight orthokeratology will have on myopia progression.

Jeff Walline, OD, MS, from The Ohio State University and I have begun to explore answering this question. Due to the lack of literature on the topic of corneal reshaping in children, we created the Children's Overnight Orthokeratology Investigation (COOKI). The purpose of this pilot study is to evaluate the safety and efficacy of overnight orthokeratology in children ages 8 through 11. Following is a case report from one of our study participants.

Figure 1. JA's baseline and one-week follow-up topography maps

Initial Fitting

Just over six months ago, an 11-year-old young man (JA) came to my office and asked to participate in the COOKI Study. After speaking with him briefly, I discovered that he was very active in athletics and wanted to rid himself of his glasses for these activities. I explained the treatment process to him, and he was eager and motivated to participate.

JA's baseline manifest refraction was ­2.25D sphere OD and ­2.00 ­0.25 x 180 OS. His baseline keratometry readings were 42.87/ 43.12 @ 090 OD and 42.37/43.37 @ 090 OS. We fit him with Paragon CRT lenses. Table 1 shows the lens parameters. Although JA is wearing lenses with a 10.5mm diameter, I often find that a smaller diameter (10.0mm) is necessary in children.

Promising Results

At the one-week follow-up appointment, JA's refraction had improved to +0.25 ­0.50 x 090 in the right eye and +0.25 sphere in the left eye, both corrected to 20/20. Figure 1 shows the baseline and one-week corneal topography maps. Unaided visual acuities were 20/25 OD and 20/20 OS. Quick results such as these are not uncommon with children.

This young man recently presented to the clinic for his six-month follow-up appointment. His refraction was ­0.25D sphere OD and ­0.50D sphere OS even after skipping two nights of lens wear. After this visit, I asked him to discontinue lens wear for one week to assess his refraction and topography readings during a "wash-out" period. We decided that his holiday break would be the best time. He did not want to wear his glasses to school. After one week of not wearing lenses, his refraction and topography returned to the baseline values.

We do not have the answer regarding myopia progression with corneal reshaping in children, but we do know that many children have succeeded in temporarily reducing their myopia with the procedure. I have had great success and fun fitting children 8 years and older with contact lenses for corneal reshaping. The children have even referred friends or relatives for fitting.

 

TABLE 1Parameters of JA's Paragon CRT Lenses 

  RIGHT EYE LEFT EYE
Base Curve 8.4mm 8.5mm
Power +0.50D +0.50D
RZD 0.525 0.525
LZA 33  33
OAM 10.5mm 10.5mm
Material  HDS100 HDS100

Dr. Rah is an assistant professor at the New England College of Optometry where she works primarily in the Cornea and Contact Lens Service in patient care, teaching and research.

 


Contact Lens Spectrum, Issue: May 2003