A new study – representing the largest sample size to date – has found orthokeratology (OK) lenses are associated with an incidence rate of microbial keratitis (MK) similar to both that seen with the use of daily wear contact lenses and results reported in previous studies.
Japanese researchers conducted a retrospective multicentre study to determine the incidence of MK among Japanese patients wearing OK lenses overnight.
This study, which included 1,438 patients (753 males, 685 females; mean age, 12.7 ± 5.4 years), was conducted at four hospitals in Japan. All patients had worn prescription OK lenses, also referred to as ortho-k lenses, for a minimum of three months.
Four cases of microbial keratitis were identified, resulting in an overall incidence of microbial keratitis of 5.4 (95% CI: 1.0–9.8) per 10,000 patient-years among OK lens wearers.
the study “represents the largest sample size to date for estimating the incidence of microbial keratitis associated with ortho-k lenses”
The authors said the study “represents the largest sample size to date for estimating the incidence of microbial keratitis associated with ortho-k lenses”.
“The incidence was similar to or slightly lower than that of previous studies on ortho-k-related microbial keratitis and also comparable to that of daily wear soft contact lenses.”
Reference
- Hiraoka T, Matsumura S, Hori Y, et al. Incidence of microbial keratitis associated with overnight orthokeratology: a multicenter collaborative study. Jpn J Ophthalmol. 2024; doi: 10.1007/s10384-024-01137-4.
