How often do children wearing soft contact lenses experience adverse events?

Paper title: Incidence of Corneal Adverse Events in Children Wearing Soft Contact Lenses

Authors: Mark A Bullimore (1), Kathryn Richdale

• College of Optometry, University of Houston, Houston, Texas

Date:  May 2023

Reference: Bullimore MA, Richdale K. Incidence of Corneal Adverse Events in Children Wearing Soft Contact Lenses. Eye Contact Lens. 2023 May 1;49(5):204-211.

[Link to open access paper]

In 2017, Mark Bullimore published a meta-analysis of pediatric soft contact lens studies (SCL) which indicated that children (aged 8-12) and teens (aged 13-17) are no more risky contact lens wearers than adults, with no higher rates of microbial keratitis (MK) or inflammatory complications - importantly, evidence indicated a lower rate of infection in children than teens and adults, which he attributed to better compliance and closer parental supervision.¹

This updated literature review examined nine studies undertaken between 2004 and 2022 in which children wore soft contact lenses for at least one year, and at least 100 patient-years of wear was followed. Four of the nine studies were published since the original review, and six of the nine included children no older than 12 years of age at fitting. Four studies included only daily disposable SCLs while the rest were reusable or mixed modalities. Any data on cases of microbial keratitis (MK) or symptomatic corneal infiltrative event (CIE) across these studies was collated to report incidence.

• Across seven prospective studies (3,752 patient years of wear in 1,756 children) only one case of MK and 16 symptomatic CIE's were reported.  These studies were undertaken in different countries, with varying  contact lens materials and replacement schedules. The analysis gave an incidence rate of MK of 2.7 per 10,000 patient-wearing years for MK and 42 per 10,000 patient-wearing years for symptomatic CIEs.
• Across two retrospective studies (2,545 patient years of wear in 1,025 children), MK occurred with a rate of 9.4 per 10,000 years, with two cases in teenage boys, resolving with no loss of acuity. Symptomatic CIEs had a rate of 75 per 10,000 patient years.
• Data on daily disposable hydrogel contact lenses showed 6 symptomatic CIE's in 2,363 patient-wearing years, giving an incidence rate of 25 per 10,000 patient years (95% CI: 11-55).
• Data on reusable silicone hydrogel contact lenses showed 10 symptomatic CIE's in 1,230 patient-wearing years, giving an incidence rate of 81 per 10,000 patient years (95% CI:44-149). The overlapping 95% confidence intervals indicate daily disposables are likely safer but the range is broad.
• The incidence of all CIEs in childhood SCL wear was 141 per 10,000 patient years (95% CI: 108-184), By comparison, studies on the incidence of CIEs in adult soft contact lens wearers yields much higher rates, in the order of 400-800, mostly with daily wear reusable SCLs.

Corneal infiltrative (or inflammatory) events, or CIEs, include contact lens peripheral ulcer, infiltrative keratitis, and at most severe, microbial keratitis (MK). MK is typically rare but has the potential for vision loss. This analysis primarily takes in data from children fit with SCLs from age 7-8, mostly no older than 12, and mostly wearing daily disposables. It further adds to the evidence that SCL wear in children holds a low risk of complications, and for these younger age groups, a lower comparable risk than for teens and adults.

• There is less overall data available for children than adults in terms of long-term contact lens wear, the impact of lens material, contact lens solutions and wearing modalities. The data available, however, indicates that the rates of CIE in children are low.
• It is not clear whether the risk of CIE is elevated in the first few months or across longer-term periods of wear.
• Classification of CIE can be a challenge, with varying methods complicating comparisons between studies.
• Some studies of myopia control with SCLs have not reported safety outcomes, potentially resulting in underreporting of adverse events.

Title: Incidence of Corneal Adverse Events in Children Wearing Soft Contact Lenses

Authors: Mark A Bullimore, Kathryn Richdale

Objectives: There is increasing interest in fitting children with soft contact lenses, in part due to the increase in prescribing of designs to slow the progression of myopia. This literature review summarizes large prospective and retrospective studies that include data on the incidence of microbial keratitis and corneal infiltrative events (CIEs) in children wearing soft contact lenses.

Methods:  Peer-reviewed prospective and retrospective studies that report contact lens-related complications in children with at least one year of wear and at least 100 patient years of wear were identified.

Results: Seven prospective studies published between 2004 and 2022 were identified representing 3,752 patient years of wear in 1,756 children, nearly all of whom were fitted at age 12 years or younger. Collectively, they report one case of microbial keratitis and 53 CIEs, of which 16 were classified as symptomatic. The overall incidence of microbial keratitis was 2.7 per 10,000 patient years (95% CI: 0.5-15), and the incidence of symptomatic CIEs was 42 per 10,000 patient years (95% CI: 26-69). Two retrospective studies were identified representing 2,545 patient years of wear in 1,025 children, fitted at age 12 years or younger. One study reports two cases of microbial keratitis giving an incidence of 9.4 per 10,000 patient years (95% CI: 0.5-15).

Conclusions: Accurate classification of CIEs is challenging, particularly in retrospective studies. The incidence of microbial keratitis in children wearing soft lenses is no higher than in adults, and the incidence of CIEs seems to be markedly lower.

[Link to open access paper]