There have been some recent reports out of Asia of infections with Ortho-K treatments. This is not something that hasn’t happened before and it certainly is something to be aware of and analyse for the reasons for the recent infections. However, there is some history when it comes to infections with Ortho-K therapy in Asia. Previously, the safety of overnight orthokeratology was called into question following a rash of microbial keratitis cases in Asia in 2001. Following these events, Watt and Swarbrick studied all reported cases of microbial keratitis associated with orthokeratology from 2001 through 2007. Strikingly, they found that half these cases occurred in 2001, and that all of those were in China, Taiwan, and Hong Kong (where, at the time, regulation of orthokeratology was limited). Most of the cases from that year could be readily linked to poor instruction in lens care or poor compliance. When practice was regulated in these countries, and practitioners were trained in contact lens safety, the rate of microbial keratitis plummeted.
At Envision, we have been performing orthokeratology since 2002 and have yet to see a corneal infection in one of these patients. In addition, a large post-market study is underway to determine the true incidence of infection in orthokeratology patients, which at this time appears be on the order of 7.7 per 10,000 per year—roughly comparable to the reported incidence in daily wear soft lenses.
Safety is increased by the fact that orthokeratology lenses are not worn during the day. Most keratitis is painful, but a contact lens that stays in the eye—eg, an extended-wear soft lens—will protect the eye and moderate the pain, at least for a period. But orthokeratology patients take their lenses out each morning. If pain persists or worsens when the lens is taken out, they are motivated to come to the office for an examination. Therefore, I believe the recent cases will prove to be linked to poor hygiene and cleaning practices, as there are many thousands of patients worldwide successfully and safely wearing OK lenses. Here are some tips we give to our patients for safe lens therapy.
Health, Safety, Hygiene
The following steps are essential to safe and effective use of your Ortho-K retainer lenses:
- Wash hands thoroughly before handling lenses
- Clean, rinse and disinfect the retainer lenses each morning as directed- a full list of instructions for lens care is provided in your Treatment Plan folder
- Attend scheduled aftercare examinations every 6-12 months or as advised
- Replace the retainer lenses with a new pair every 12-24 months or as advised
- Replace the lens container with a new container every 3 months
- Become an eyecare detective- each morning upon lens removal, look in the mirror and check your eyes to see if they “look good, feel good, see good”
The safety of your eyes is our primary concern at Envision. Placing a lens on the surface of the eye carries a risk of eye infection. Compared with soft contact lenses, Ortho-K lenses have a relatively low risk. Logically, the risk of infection is higher than wearing glasses.
The golden rule is : “if in doubt, take them out”. Do not ignore warning signs such as discomfort especially if it is just before going to sleep. Remove the lens, rinse and carefully re-apply. If the eye still feels irritated, remove the lens and do not re-apply until the eye feels normal again. Should the problem persist, see us immediately for urgent advice. Do not be concerned at missing one or two nights of treatment – persisting when you have an irritated or sore eye can be dangerous.