Independent of accommodation
Optical axial length does not swing with a child's focusing the way a dry refraction can.
Myopia management · Diagnostics
Axial Length Biometry The number that shows whether treatment is working.
Refraction drifts with accommodation and cycloplegia. Axial length, measured by optical biometry, tracks eye growth directly and gives a repeatable baseline for every myopia patient. Several biometers now pair it with growth curves and parent-ready reports.
±0.03 mmTopcon MYAH in vivo axial length repeatability
~0.02 mmMyopia Master repeat measurement SD, as OCULUS reports
20,000+Eyes behind the Myopia Master growth curves
Non-contactOptical biometry, no probe on the eye
Why it matters
Track growth, not just prescription
Myopia progresses because the eye gets longer. Measuring that length lets you compare a child against age norms and judge whether a treatment is holding.
Growth curves
Percentile charts by age and sex show where a child sits and where the eye is heading.
Treatment check
Annual growth compared with age-matched norms gives an objective read on efficacy.
Family conversation
A curve on a screen explains progression to parents faster than diopters do.
Documentation
Serial measurements support the record behind a program fee and any change in therapy.
Biometers built for myopia clinics
These platforms combine optical biometry with myopia software. Confirm current specifications and pricing with each manufacturer.
- Optical, non-contact measurement
- Growth-curve software
- Exportable family reports
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OCULUS Myopia Master
Axial length, refraction and keratometry in one roughly two-minute process, with BHVI-based growth curves and a Growth Control module.
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Topcon MYAH
Low-coherence interferometry axial length (15 to 36 mm) plus 24-ring Placido topography, pupillometry and ortho-k fitting tools.
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Haag-Streit Lenstar Myopia
Lenstar 900 optical biometry with EyeSuite Myopia software and growth curves from Erasmus University Medical Center.
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Surgical biometers
Cataract biometers also measure axial length. Check whether yours offers myopia software and pediatric norms.
In the practice
Where biometry fits the workflow
A trained technician can capture axial length in minutes, so it slots in before the doctor sees the child.
Baseline visit
Measure both eyes alongside cycloplegic refraction and keratometry and record the percentile.
Every recheck
Repeat on the same device at each follow-up so changes reflect the eye, not the instrument.
Decide and explain
Use annual growth against norms to continue, add or switch therapy, and share the report with the family.
Specifications
Published device specifications
| Myopia Master axial length range | 14–40 mm |
|---|---|
| Myopia Master refraction | Sphere −20 to +22 D; cylinder to 10 D |
| Myopia Master keratometry | 6–10 mm radius |
| Myopia Master size and weight | 266 × 538 × 493–523 mm; about 12 kg |
| MYAH axial length method | Low-coherence interferometry, 820 nm SLED |
| MYAH axial length range | 15.00–36.00 mm, 0.01 mm resolution |
| MYAH topography | 24 Placido rings, corneal coverage to 9.8 mm |
| MYAH keratometry range | 28.00–67.50 D |
| MYAH weight | 18 kg |
| Lenstar Myopia platform | Lenstar 900 optical biometer with EyeSuite Myopia |
Questions doctors ask about axial length
Do I need a biometer to start myopia management?
No. Many practices start with cycloplegic refraction. A biometer makes follow-up more objective and is worth adding as volume grows.
Can I bill axial length measurement?
There is no dedicated myopia biometry code, and surgical biometry codes are tied to lens power calculation. Most practices include it in a program fee. See the coding guide.
Which growth curves should I trust?
Each device uses its own reference data, such as BHVI or Erasmus MC curves. Use one device consistently for each child.
Who runs the test?
A trained technician. The measurement is non-contact and takes minutes.
Does a topographer double as a biometer?
Only some do. The Topcon MYAH combines both; most topographers do not measure axial length.
References
- OCULUS. Myopia Master product page and specifications. OCULUS
- Topcon Healthcare. MYAH product information. Topcon
- Haag-Streit introduces Lenstar Myopia for myopia management. Eyewire News, 2021. Eyewire
- Tideman JWL, Polling JR, Vingerling JR, et al. Axial length growth and the risk of developing myopia in European children. Acta Ophthalmol. 2018;96(3):301-309. PubMed
Measure what parents care about.
Axial length turns a myopia program into a measured service with a visible result.
Myopia Master, MYAH and Lenstar are trademarks of their respective manufacturers. Specifications are from manufacturer materials and may change. Individual results vary.