Biometry
Pronunciation: bye-OM-eh-tree
Precise measurement of ocular dimensions used to calculate intraocular lens power for cataract surgery.
Full Definition
Biometry is the precise measurement of ocular parameters necessary for accurate intraocular lens (IOL) power calculation in cataract surgery. Key measurements include axial length, anterior chamber depth, lens thickness, and corneal curvature (keratometry). Modern biometry uses optical techniques such as partial coherence interferometry (PCI) or optical low-coherence reflectometry (OLCR) to achieve sub-millimeter accuracy. These measurements are input into various IOL calculation formulas to predict the appropriate lens power for achieving desired post-operative refractive outcomes.
Usage
Usage note: Distinguished from general biometry (biological measurements). In ophthalmology, usually refers specifically to IOL calculations.
In Context
- "Optical biometry revealed an axial length of 24.5 mm with steep corneal curvature." — Preoperative measurement
- "Dense cataracts prevented reliable optical biometry, requiring ultrasound A-scan." — Technical note