Long-term nightly use of corneal refractive therapy lenses was associated with elevated levels of tear film inflammatory mediators, a study found.
“The evaluation of levels of inflammatory mediators at the ocular surface is … important to know if the cornea undergoing corneal refractive therapy could be compromised,” the study authors said.
The prospective study included 60 eyes of 60 patients with a mean age of 26.4 years. Thirty-two patients with a mean age of 27 years wore corneal refractive therapy lenses overnight for 12 months; 28 patients with a mean age of 25.5 years wore continuous-wear silicone-hydrogel lenses for 12 months. A comparator group comprised 32 patients with a mean age of 26.7 years who did not wear contact lenses.
Investigators collected tear samples 12 months after initial lens fitting and tested them for cytokines interleukin (IL)-6 and IL-8, matrix metalloproteinase-9 (MMP-9) and epidermal growth factor (EGF), which are all associated with the wound healing response.
Study results showed that samples from silicone-hydrogel lens wearers and controls had similar mean values of IL-6, IL-8 and MMP-9. However, samples taken from corneal refractive therapy lens wearers had significantly elevated levels of IL-6, IL-8 and MMP-9 (all P < .001).
EGF concentrations were significantly higher in samples taken from silicone-hydrogel lens wearers and corneal refractive therapy lens wearers compared with controls (both P < .001).
Data showed a strong correlation between inflammatory response and degree of myopia in the corneal refractive therapy group, the authors said.