This article is more than 5 years old. Information may no longer be current.
Ultrathin cornea ‘remarkably stable’ after PTK re-treatment
Click Here to Manage Email Alerts
MONTE CARLO, Monaco — Thin corneas after phototherapeutic keratectomy — even those with residual stromal thickness below the typical safety range of 250 µm to 300 µm — showed a “remarkable refractive stability and are probably less likely to develop ectatic disease,” according to speakers here at the European Society of Cataract and Refractive Surgeons Winter Refractive Surgery meeting.
“This is probably due to the more even distribution of forces that the smoothing effect of phototherapeutic keratectomy (PTK) treatment induces on the cornea. An elastic band that is thinner, but regular, is likely to be stronger than an elastic band with a larger diameter but a narrowing of the lumen at some point,” said Paolo Vinciguerra, MD. “PTK smooths the surface and therefore gives this extra strength to even very thin corneas. The limit of thickness reduction in re-treatment can therefore be extended beyond commonly accepted values.”
Ultraviolet light exposure over 30 minutes during excimer-laser PTK may also cause some degree of collagen cross-linking that could add extra strength to the corneal tissue, added Fabrizio Camesasca, MD.
“In conclusion,” Dr. Camesasca said, “in re-treatment with PTK, very low residual corneal thickness is compatible with long-term stability, and penetrating keratoplasty can be avoided in most cases.”