No severe adverse events leaving permanent damage to vision during the treatment period were reported in the included ortho-K studies analyzed. Photo: Robert Ensley, OD, and Heidi Miller, OD. Click image to enlarge.

With myopia control efforts increasingly adopted by eyecare providers in recent years, new data is always welcome. Researchers in China decided to conduct a systematic review and meta-analysis to evaluate orthokeratology (ortho-K) at different time points over a two-year period. Their analysis determined that ortho-K could effectively reduce axial length (AL) elongation of myopia children within six months, with a prolonged effect up to 24 months; however, myopia control success declined over follow-up, with rates of 64%, 53%, 50% and 47% recorded for six, 12, 18 and 24 months, respectively.

The meta-analysis included seven studies involving 655 eyes. There were significant differences in the effects of ortho-K vs. control in slowing AL elongation, with weighted mean differences of -0.11mm at six months, -0.16mm at 12 months, -0.23mm at 18 months and -0.28mm at 24 months. The researchers also found no statistical significance for adverse events between the ortho-K and control groups. A subgroup analysis noted that Caucasian children received more benefits than East Asian children in 12 months and high myopia children received more benefits than children with low to moderate myopia in six months and 12 months.

“These results remind us that the situation of myopia control for East Asian children was more serious than European,” the team wrote in their paper for Eye & Contact Lens. “Although ortho-K was designed as an optical correction mainly for correcting low to moderate myopia, it can also be used in high myopia children for myopia control and have better results.”

“The mechanism of myopia progression is still needed to further elucidate the potential biological mechanisms of ortho-K for myopia control,” they added. “Long-term efficacy and acceptability also need more long-term research to confirm our data.”