Article Date: 1/1/2006

orthokeratology today
Sometimes, Ortho-k Works Too Well
BY JOHN MOUNTFORD, DIP. APP. SC, FAAO, FCLSA

Figure 1. The cornea in cross-section. Note the granular haze that extends into the stroma.

Like most practitioners, I send annual reminders to my contact lens patients advising them that it's time for a review. It's disconcerting how relatively poor the compliance of ortho-k patients is compared to disposable lens wearers. This is probably because soft lens wearers can't get a prescription renewal unless they present for review. When ortho-k patients finally present, it's usually because of the lenses losing effect as a result of surface deposits.

An Ortho-k Patient Returns

A patient presented for review five years after his last ortho-k checkup, with the main complaint being discomfort. He was wearing the lenses every second night and reported excellent vision when not wearing lenses. His original Rx was OD –1.75D, OS –2.50D.

Vision was OD and OS 20/15 with refraction giving +0.25D OU. The real shock came with the slit lamp examination. Both corneas exhibited a central circular area of haze about 3.00mm in diameter. There was a "granular" epitheliopathy, mild disruption of Bowman's Membrane and stromal haze extending to approximately 25 percent of the corneal thickness (Figure 1). The palpebral conjunctiva showed grade 3 follicles and hyperemia.

Figure 2. The lenses were opaque with surface deposits on both surfaces.

The presenting complaint was discomfort, with no reference to decreased vision. Furthermore, the discomfort had occurred only in the last month. When asked why he hadn't presented for routine review as per the reminder notices, he replied that there was no need because he wasn't having any problems until the lenses became uncomfortable. Figure 2 shows the deplorable state of the lenses, which were opaque with surface deposits.

A build-up of surface deposits, especially on the lens' back surface, is known to cause a loss of the ortho-k effect and an increase in superficial punctate keratitis. We advised the patient to cease lens wear and return for weekly follow up. No medication was indicated or prescribed. The epitheliopathy and haze gradually resolved over a period of four weeks (Figure 3), leaving the cornea crisp and clear. We prescribed new lenses and ortho-k recommenced, with the patient vowing to return annually.

Figure 3. Cornea after four weeks of no lens wear. The haze has resolved.

Strong Words

Sometimes we're too successful, especially with ortho-k. If patients remain problem-free, they may not see the need for annual reviews. I think I'll reword my reminders and make them a bit more forceful.

Dr. Mountford is an optometrist in private practice specializing in advanced contact lenses for keratoconus, post refractive surgery and pediatric aphakia. He is a visiting contact lens lecturer to QUT and UNSW, Australia.



Contact Lens Spectrum, Issue: January 2006