We know from surveys that some practitioners wait until their patient is a teenager before broaching the option of contact lenses.1 Nonetheless there are many reasons why children as young as 8 years old—and even younger—should be considered candidates for contact lenses.
Contact lenses give a child freedom from spectacles. This may reduce teasing from their peers but also allows them to safely participate in sports without sacrificing visual performance. More importantly, contact lenses have been shown to improve a number of aspects of quality of life in children as well as being an excellent option for myopia control.
How soft contact lenses improve a child’s quality of life
A number of studies have assessed quality of life in children wearing contact lenses—both single vision and those used in myopia management.
The Adolescent and Child Health Initiative to Encourage Vision Empowerment (ACHIEVE) Study randomly assigned myopic children to wear spectacles or soft contact lenses for 3 years.2 Perceptions of physical appearance, athletic competence, and social acceptance were all greater among contact lens wearers.
The authors also assessed vision-related quality of life and the three scales with the greatest improvement in contact lens wearers were activities, appearance, and satisfaction with correction.
Weighing the safety concerns for pediatric patients
The adverse events associated with soft contact lens wear have been studied extensively. Those affecting the cornea are collectively termed corneal infiltrative events,3,4,5 and the vast majority are easily managed and pose little threat to vision.4,6 Microbial keratitis is a rare subset of these events, with an incidence of between 2 and 4 per 10,000 patient years for daily-wear patients,7 with around 5% resulting in vision loss.8,9,10,11
Soft contact lens wear appears to be safer in 8- to 12-year-olds than in adolescents and young adults. A retrospective study of 3,549 patients, including children and teenagers, found that the risk of a corneal infiltrative event increased in a nonlinear fashion up to age 21 and then decreased, with the peak years at risk from age 15 to 25 years.4
Comprehensive prospective studies have found the rates of corneal infiltrative events and microbial keratitis in patients 8 to 12 years old to be consistently low.12,13
Focus on contact lenses for myopia control
One emerging reason for promoting contact lenses in children is myopia control. Myopia prevalence is increasing and the consequences of sight-threatening complications later in life have been well established, including myopic maculopathy, retinal detachment, and primary open-angle glaucoma.2
While we used to consider myopia as a benign refractive condition, a recent report from the National Academies of Science Engineering and Medicine declared that myopia should be considered a disease.14 Furthermore it has been demonstrated that myopia is responsible for a third of uncorrectable visual impairment in the US.15
Studies on vision-related quality of life
Two studies have assessed vision-related quality of life in children wearing myopia-control soft contact lenses. In the first, comparing dual-focus soft contact lenses and single-vision spectacles, those wearing contact lenses had higher scores for appearance, satisfaction, activities, handling, and peer perceptions.16
The second compared children wearing Defocus Incorporated Soft Contact (DISC) lenses and single-vision spectacles for at least 6 months.17 Those wearing the soft lenses scored significantly higher for vision, appearance, activities, and peer perception.
Researchers have also compared quality of life between children wearing overnight orthokeratology and spectacles. The first study found those wearing orthokeratology rated overall vision, far vision, symptoms, appearance, satisfaction, activities, academic performance, handling, and peer perceptions significantly higher than those wearing spectacles.18
A subsequent study found that overall vision, far vision, appearance, satisfaction, activities, and peer perception scores were all higher in the overnight orthokeratology wearers than in the spectacle wearers.19
Assessing quality of vision in myopia patients
Contact lenses move with the eye and offer excellent quality of vision in all directions of gaze. Nonetheless, the simultaneous vision nature of myopia control soft lenses means that some reduction in vision quality might be anticipated under some conditions.
In the 3-year clinical trial of a dual-focus soft contact lens, best-corrected visual acuity with the lens was no different from that with single vision soft lenses.20,21 Presenting visual acuity was often worse with the single vision lenses than the dual-focus lenses due to greater myopia progression.21
After 6 years of wear, over 90% of participants rated themselves as seeing “kind of well” or “really well,” with the latter accounting for the vast majority of those responses.21 Likewise, visual disturbances such as ghosting or haloes were reported to be “not noticeable” or “noticeable, but not annoying,” in 90% or more of children.
In the 6-month randomized clinical trial comparing three myopia control soft contact lenses with a single vision lens, there was no significant difference in visual acuity at initial lens fitting or after 6 months of wear for any lens group compared to best-sphere spectacle correction.22
Finally, a 3-year clinical trial of high and medium add power soft contact lenses found that visual acuity with spherical over-refraction was no different from that with single vision soft lenses with an over-refraction.23 Both high and medium add power lenses gave significantly poorer low contrast visual acuity, but the differences were less than two letters and considered by the authors to be “not clinically meaningful.”
Ortho-K yields excellent results
An important benefit of overnight orthokeratology is the temporary reduction of myopia and the associated elimination of a need for optical correction. Adults undergoing overnight orthokeratology show excellent uncorrected visual acuity and little change throughout the day.24,25,26,27
Consistent with studies of soft lens myopia control,21 presenting visual acuity in children wearing overnight orthokeratology was better than in single vision wearers due to less myopia progression. For example, at the conclusion of a 2-year clinical trial, presenting visual acuity was around half a line better in children wearing overnight orthokeratology than those in spectacles.28
Careful studies in adults found no significant changes in best-corrected high contrast best-corrected visual acuity.29 Nonetheless, low contrast best-corrected visual acuity was reduced by around one line, correlating with an increase in spherical aberration.
Examining the safety of lenses for myopia management
Most myopia control contact lenses are daily disposable replacement schedule,20,22 and the elimination of contact lens storage and solutions eliminates two important risk factors for microbial keratitis.30
A retrospective study of 1,317 randomly selected overnight orthokeratology wearers in the United States identified eight corneal infiltrative events of which two were classified as microbial keratitis.31 Both occurred in children but neither resulted in a loss of visual acuity. The estimated incidence of microbial keratitis in children was 14 per 10,000 patient years.
A second study in Russia identified five cases of microbial keratitis without permanent loss of vision in children wearing overnight orthokeratology lenses and estimated the incidence as 5 per 10,000 patient years.32 Finally, among 1,438 Japanese patients with a mean wearing history of over 5 years, four cases of microbial keratitis were identified, resulting in an overall incidence of microbial keratitis of 5.4 per 10,000 patient years.33
In conclusion, microbial keratitis is rare in contact lens wear and highly unlikely to result in permanent loss of vision, particularly in children. Furthermore, the benefits of myopia control far outweigh these risks.7 The risk can be mitigated by daily-disposable lenses and frequently reinforcing the importance of good hygiene and compliance.30
The importance of compliance in pediatric patients
Compliance with spectacles and contact lenses is influenced by a range of factors, including comfort, vision, motivation, lifestyle, and the benefits associated with the modality.
There are clear examples where higher compliance, in terms of wearing time, has been shown to be associated with greater efficacy of myopia control.
Let’s look at the research
The aforementioned clinical trials of dual-focus20 and multifocal soft contact lenses23 did not find any relation between lens wearing time and myopia control efficacy, probably because the mean wearing time was around 13 hours per day in the former.
A 2-year randomized clinical trial compared myopia progression between children wearing the DISC lens and those wearing a single vision contact lens.34 Mean wearing time was only around 6.5 hours per day in both groups, around half that reported in similar studies.20,23
In a subgroup analysis, when only participants who wore the lenses at least 8 hours per day were considered, the 2-year myopia control efficacy increased from 0.21D to 0.53D.34 Finally, a 6-month clinical trial compared a number of prototype myopia control soft contact lenses and single-vision designs.22 While mean wearing time exceeded 12 hours for all lenses, it was still found to influence the slowing of axial elongation.
In summary, compliance can be an important determinant of myopia control efficacy. Given the relative ease with which spectacles may be removed, common sense suggests that compliance should be higher with contact lenses, particularly overnight orthokeratology where quality of vision and comfort play little role during most of the wear time.
Conclusion
In summary, soft contact lenses, be they single vision or for myopia control, improve quality of life in children.
However, there are many considerations when making recommendations to patients and refractive correction in children is no exception.
To take a deeper dive into some of the issues discussed here, please see our recent paper.35
