Study finds incidence of microbial keratitis associated with overnight orthokeratology

News
Article

The incidence was comparable to that of daily wear soft contact lenses.

Child putting in contact lenses at desk Image credit: AdobeStock/irena_geo

Image credit: AdobeStock/irena_geo

A recent study found that orthokeratology lenses, which are worn overnight to reshape the cornea to improve vision and eliminate the need for correction during the day, was associated with an incidence rate of microbial keratitis similar to both that seen with the use of daily wear contact lenses and results reported in previous studies,1 according to first author Takahiro Hiraoka, MD, PhD, and colleagues. He is from the Department of Ophthalmology, Institute of Medicine, University of Tsukuba, Ibaraki, Japan.

The research team conducted a retrospective multicenter study to determine the incidence of microbial keratitis among Japanese patients wearing orthokeratology lenses, referred to as ortho-k lenses.

This study, which included 1,438 patients (753 males, 685 females; mean age, 12.7 ± 5.4 years), was conducted at 4 hospitals in Japan. All patients had been prescribed the orthokeratology lenses and wore them for a minimum of 3 months.

The investigators collected data from the medical records on patient demographics, lens characteristics, lens care systems and presence of microbial keratitis. They calculated the time that the patients wore the lenses from the fitting date to the patient's last visit, with the total years of lens wear used as person-years of lens wear. The incidence of microbial keratitis was calculated by dividing the number of infected cases by the total person-years of lens wear for all enrolled participants, the authors explained.

The data analysis showed that the mean duration of orthokeratology lens wear was 5.2 ± 4.5 years, and the mean lens power was -3.52 ± 1.41 diopters. The total person-years of lens wear for all patients was 7,415.

Among the study patients, 4 cases of microbial keratitis occurred, for an overall microbial keratitis incidence of 5.4 (95% confidence interval, 1.0–9.8) per 10,000 patient-years.

The investigators commented, “This 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:
  1. Hiraoka T, Matsumura S, Hori Y, et al. Incidence of microbial keratitis associated with overnight orthokeratology: a multicenter collaborative study. Jpn J Ophthalmol. 2024; https://doi.org/10.1007/s10384-024-01137-4

Newsletter

Want more insights like this? Subscribe to Optometry Times and get clinical pearls and practice tips delivered straight to your inbox.

Recent Videos
Dana Shannon, OD, FAAO, shares pearls on spotting red flags in need of referral and enhancing patient care with follow-up compliance.
Dana Shannon, OD, FAAO, detailed a lecture she gave at the NOA Midwestern Symposium earlier this month.
Melissa Barnett, OD, FAAO, FSLS, FBCLA, gave 2 presentations alongside other ODs and MDs at CRU 2025.
Melissa Tawa, OD, FAAO, provides insights to take glaucoma management from reactive to proactive in presentations given at CRU 2025 in Napa, California.
Rachelle Lin, OD, MS, FAAO, details her presentation on inherited retinal diseases at CRU 2025.
Setting the stage in LA: Neda Shamie, MD, on the 19th annual Controversies in Modern Eye Care meeting
Jennifer Li, MD, details a talk she gave alongside Melissa Barnett, OD, FAAO, FSLS, FBCLA, at CRU 2025 in Napa, California.
Deb Ristvedt, DO, details a handful of presentations on glaucoma she gave during CRU 2025 in Napa, California.
Cecelia Koetting, OD, FAAO, DipABO, weighs in on patient assessments, staining pattern insights, and diagnostic tips for patients who may have dry eye disease.
Melissa Barnett, OD, FAAO, FSLS, FBCLA, discusses keratoconus management, diagnosis, and other key insights at CRU 2025.
© 2025 MJH Life Sciences

All rights reserved.