Researchers recently reported that overnight orthokeratology (ortho-K) may not achieve favorable outcomes in younger patients. They found that short-term use may reduce tear film stability and increase corneal epithelium damage, while long-term use could induce ocular inflammation by disrupting the meibomian glands.
This non-randomized, prospective pilot study evaluated 60 myopes treated with overnight ortho-K and 60 age-matched controls who wore spectacles. A team performed the following tests before and after one, three, six and 12 months: Ocular Surface Disease Index (OSDI), noninvasive tear break-up time (TBUT), tear meniscus height, corneal fluorescein staining and noncontact meibography. They assessed the concentrations of interleukin-17A (IL-17A), interleukin-6 (IL-6) and prostaglandin E2 (PGE2) in tear samples.
Prior to treatment, they did not observe any statistical differences between the two groups. Aside from trace to moderate corneal staining and allergic conjunctivitis in the treatment group, they did not detect any adverse events.
The investigators discovered that noninvasive TBUT significantly decreased after six and 12 months, staining significantly increased at each follow-up time point and the upper and total meiboscores increased gradually and peaked at 12 months after overnight ortho-K wear. They noted no significant differences in OSDI or tear meniscus height at any follow-up time point compared with baseline in either group.
The study authors also found that the concentrations of the three cytokines in the treatment group significantly increased, with IL-17A increasing significantly at three months, IL-6 at six months and PGE2 at 12 months. However, they added that there were no significant changes in the control group.
|Yang L, Zhang L, Hu RJ, et al. The influence of overnight orthokeratology on ocular surface and dry eye-related cytokines IL-17A, IL-6, and PGE2 in children. Cont Lens Ant Eye. April 29, 2020. [Epub ahead of print].|