25 July: Ortho-K Follow-up

In the shop I work at, we don't prescribe Ortho-K.  Nor do we have its trial lenses set.  However my boss had gone to a few ortho-K courses previously.  When we received a phone call from a customer, who was referred from another optical shop in Melaka, my boss and I were a bit worried, wondering what the case is.  As we had suspected, it was a case of Ortho-K.  but luckily, not a fitting session, only a follow-up.  The customer had worn the current ortho-K for 3 months, and we wanted to know how effective the ortho-K is for him, and if the lenses cause any adverse effect in his eyes.

Firstly... what is Ortho-K?  It is a non-surgical procedure with the purpose of reducing the refractive errors of nearsightedness (myopia), farsightedness (hyperopia) and astigmatism.  How does it work?  The cornea is flattened by a hard contact lens (as shown below).  The hard lenses are worn for a few hours, commonly at night. These lenses flatten the cornea, and thus reducing the refractive power of the cornea.

So anyway... we carried out the follow-up.  We checked his visual acuity (how well he can read the Snellen chart), do refraction (check his eye's current refractive error, better known as 'power') and also do a slit lamp evaluation.  The subjective refraction done by retinoscopy shows confusing reflections, which my sifu (a.k.a. my boss) tells me is quite typical in Ortho-K patients as well as post-lasik patients.  There are Fleischer's-like brown ring which could be observed under the slit lamp.  This is not an unusual occurrence, however, as several journals have also reported of the same ring.  There are also some neovascularization on his eyes, but very minor ones.

All in all.... it is the first time I ever observed and attempted to do follow-up on Ortho-K patient (though with a lot of help from my sifu).  I learnt that their refraction with retinoscope tends to be a bit different, and of the brownish-rings which will sometimes appear on the cornea.

Well... I guess, that's all for now... you can find more regarding ortho-K in some of the links I share bellow (which I also did take some info from).

Sources:
http://www.ortho-k.net/
http://www.ncbi.nlm.nih.gov/pubmed/12322926
http://www.allaboutvision.com/contacts/orthok.htm

Pictures courtesy of Google search engine.