Science

Science

Does myopia occur earlier in children if their parents are myopic?

This multi-ethnic study found that parental myopia was a risk factor for myopia development in pre-school age children. The age the parents became myopic themselves had a dose-dependent effect in their children if both parents had onset of myopia before age 12. Eye care practitioners can use this to identify which children may benefit from early myopia treatment intervention.

How common is microbial keratitis in children wearing orthokeratology?

The risk of microbial keratitis (MK) in orthokeratology-wearing children was shown in a 2013 analysis to be around 14 per 10,000 patient wearing years, but new data indicates that it may be lower. Data gathered from a large group of practices in Russia found MK risk of around 5 per 10,000 patient-wearing years, similar to the risk of daily wear soft lenses. This should increase confidence in fitting orthokeratology to children for myopia control.

What is the effect of uncorrecting, undercorrecting and overcorrecting myopia in children?

This systematic review of 9 studies confirms that under-correction of myopia does not slow progression; rather, at least half of the studies have shown the myopia progression is accelerated. There was no benefit found in overcorrection, and the evidence for un-correction was equivocal. Clinically, this advocates for the full correction of myopia.

Exploring the limits of myopia control efficacy

Considering even emmetropic eyes elongate, what are the limits of myopia control efficacy? This novel analysis explores the absolute axial elongation of treated and untreated myopes in the MiSight 3-year clinical trial in comparison to previously published models of myopic and emmetropic eye growth. The results indicate a potential limit to the short-term percentage efficacy of myopia control treatments.

Learning more about ‘normal’ axial elongation in emmetropic children

Previous multi-ethnicity studies have shown ‘normal’ axial elongation in emmetropic children to be around 0.1mm / year. In this study, 700 Chinese schoolchildren with stable emmetropia showed 0.2mm per year axial elongation from age 7-11, which reduced with age and ceased at age 15. This appears higher than measured in Singaporean Chinese children in the SCORM study, 20 years ago.

Multifocal contact lenses and higher order aberrations – a potential myopia control mechanism?

Total spherical-like higher-order aberrations (HOA) increased by more than double in the distance-centred +2.50 Add compared to +1.50 Add, with total coma-like HOA increasing further. Since orthokeratology studies have reported an association between more change in HOAs and better myopia control efficacy, this could indicate a mechanism of action in multifocal contact lens myopia control.

How accurate is subjective reporting of near work and outdoor time?

Young adults wearing the spectacle-mounted Clouclip device to measure viewing behaviour and light exposure also kept an activity diary. Mean daily near work and outdoor time were subjectively reported at about 150% of the objectively measured hours. This indicates the value of objective measures in research, as well as for clinical education and behaviour modification tools in future.

Orthokeratology treatment zone diameter in slow and fast progressors

A sample of slow and fast progressors in prior 24 month orthokeratology clinical trials were found to have the same baseline refraction and axial length. The slow progressors were older, and showed 0.5mm smaller treatment zone diameters (TZDs), but no difference in induced peripheral myopic shift. There was also no direct correlation between TZD and axial elongation, indicating an intriguing but not yet defined relationship.

Multifocal contact lenses don’t influence peripheral vision detection in young adults

Young adults fit with CooperVision Proclear multifocal contact lenses showed no loss of peripheral vision detection ability compared to single vision contact lenses. The near add was chosen to generate +0.50 or +1.00 of peripheral blur, confirmed by peripheral refraction measurement. This is a positive indication that fitting MFCLs in young wearers doesn’t impact peripheral visual performance.

Light-emitting glasses alter axial length and choroidal thickness in young adults

Light-emitting glasses worn by young adults for 1-2 hours reduced axial length and increased choroidal thickness by around 20 microns compared to darkness. The study participants viewed a colour-muted television at 5m while indoors, and the changes regressed within 30 minutes. A future myopia treatment to increase ‘outdoor’ time?