Orthokeratology, or “ortho-k,” is the fitting of specially designed gas permeable contact lenses that are worn during sleep to reduce or eliminate myopia without surgery.

Ortho-k is an alternative to LASIK surgery for nearsighted individuals who want to see clearly without glasses or contacts and are too young for laser vision correction or for some other reason are not good candidates for refractive eye surgery.

Researchers in Japan recently evaluated the reversibility of orthokeratology. Reversibility is desirable, as teenagers who undergo ortho-k may want to have LASIK surgery later, and it is important for eyes undergoing laser vision correction to be healthy and have a stable refractive error. Also, the researchers wanted to know if ortho-k causes any long-term loss of best-corrected visual acuity after the treatment is discontinued.

The study evaluated 17 nearsighted subjects who underwent ortho-k for a period of 12 months. The following measurements were taken prior to ortho-k, 12 months after commencement of the procedure, and one week and one month after ortho-k was discontinued:

• Refractive error
• Corneal topography
• Wavefront aberrometry to evaluate higher-order aberrations
• Visual acuity with a standard eye chart
• Contrast sensitivity

The study showed that  after one week of discontinuing wear of the ortho-k lenses, all measurements returned to the pre-treatment levels. The researchers concluded that orthokeratology is completely reversible, as determined by measurements of corneal shape, refractive error, visual acuity and quality of vision.

Source:  Recovery of corneal irregular astigmatism, ocular higher-order aberrations and contrast sensitivity after discontinuation of overnight orthokeratology. British Journal of Ophthalmology. February 2009.

Contact lenses coated with stem cells restored sight for patients with corneal damage in a new Australian study. The study involved three people who were blind in one eye. The researchers took stem cells from the cornea of their healthy eyes and cultured the cells in extended wear contact lenses. Within 10 to 14 days of wearing the contacts, the stem cells began to re-colonize and repair the damaged cornea.

After the procedure, two of the participants who were legally blind could read the large letters on an eye chart. The third participant was able to pass the vision test for a driver’s license. All three participants have had improved vision for the last 18 months.

Dr. Nick Di Girolamo of the University of New South Wales said the procedure also works for patients with damage to both eyes. In those cases, stem cells can be taken from the conjunctiva instead of the cornea. He predicts that the technique could be used to repair the retina as well.

Unlike other techniques, this procedure is non-invasive, simple and inexpensive. This could be especially beneficial for poorer countries. The researchers have applied for additional funds to continue the study, recently reported in The Australian.

SynergEyes, Inc. (Carlsbad, CA) recently announced it has launched its next generation hybrid contact lens design for keratoconus. The new lens, called ClearKone, has a patent-pending design that vaults the irregularities of a keratoconic cornea and restores vision to a vast majority of patients without compromising comfort or eye health, according to the company.

Hybrid contact lenses have a central zone identical to a rigid gas permeable (GP) contact lens, surrounded by a peripheral zone made of a soft contact lens material. The lenses are designed to provide the optical clarity of a GP contact lens, with wearing comfort comparable to a soft contact lens.

The design of hybrid contact lenses makes them especially suited for fitting many types of hard-to-fit eyes, including those with misshapen corneas due to conditions such as keratoconus and ectasia following LASIK or other laser vision correction surgery.

“SynergEyes recognized the need to develop a hybrid contact lens design that could fit a much broader spectrum of keratoconus patients, including oval cones, highly advanced central cones, decentered cones and, depending on the specifics of the case, globus keratoconus and pellucid marginal degeneration,” says Kellie Kaseburg, Vice President of Global Marketing for SynergEyes. “The ClearKone lens does just that and will allow many more keratoconus patients to experience the benefits of hybrid technology.”

ClearKone is currently available in limited release in the United States, Canada and Puerto Rico. The lens will be more widely available starting in September 2009. For more information, visit www.synergeyes.com.