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Axial Length of the Eye?, AXL, IOL master? A-scan, ultrascan
eye_doc 2025. 4. 19. 21:48👁 What is Axial Length of the Eye?
Axial Length (AXL) refers to the distance from the anterior corneal pole to the posterior scleral pole—
essentially the front-to-back length of the eyeball.
🧬 Basic Eye Anatomy
- Cornea (anterior 1/6):
- Radius: ~8mm
- Sclera (posterior 5/6):
- Radius: ~12mm
- The eye is a non-perfect sphere, composed of two fused spherical parts.
📏 Axial Length Growth
AgeAxial Length
| At birth | ~18mm |
| Age 3 | ~23mm |
| Age 14+ | ~23–24mm |
- Rapid growth occurs in early childhood
- Final adult size is usually reached in teenage years
- Influenced by refraction type (myopia/hyperopia), race, gender, measurement method
🔍 Findings from Korean Studies
YearSubjectsMean AXLMethod
| 1983 | 170 adults | 23.5–23.99mm | A-scan ultrasound |
| 1990 | 150 adults | 23.0–23.49mm | A-scan |
| 2003 | 150 adults | 23.939mm | Partial Coherence Interferometry (IOL Master) |
✅ Summary
- Normal adult axial length: 23–24mm
- May vary with age, sex, refraction type, and equipment used
- Accurate AXL is crucial in cataract surgery, myopia control, and refractive analysis