Lateral similarity and symmetry of biometric data from the LenStar in a population with cataract.
Corneal astigmatism axis matches closely between eyes when mirrored, not directly compared.
Lateral similarity and symmetry of biometric data from the LenStar in a population with cataract.
To investigate the similarity and symmetry of biometric measures between eyes in a large dataset of measurements of both eyes taken with the LenStar optical biometer.
Cross-sectional non-randomised study evaluating a dataset containing 13,420 bilateral LenStar 900 biometric measurements on patients without history of eye surgery or ocular pathology taken before cataract surgery, consisting of scalar parameters axial length AL, corneal thickness CCT, anterior chamber depth ACD, lens thickness LT and corneal diameter WTW.
when flipped like a mirror, the two eyes' astigmatism angles nearly line up
Mean / standard deviation (squared correlation coefficient) difference between right and left eye measures was 0.02 ± 0.31(0.95) / 0.00 ± 0.01(0.93) / 0.00 ± 0.14(0.88) / -0.01 ± 0.22(0.78) / -0.02 ± 0.17(0.87) mm for AL / CCT / ACD / LT / WTW and -0.06 ± 0.48(0.92) dioptres for KEQ.
Keratometric astigmatism showed a high degree of mirror symmetry (KC45 of left eyes inverted in sign) which outperforms direct symmetry.
In most cases, biometric measures match between eyes of a subject, but there are rare situations with large deviations between eyes. Keratometric astigmatism exhibits mirror symmetry.
In most cases the biometric measures from the contralateral eye could be used where biometry is unavailable or to double-check before cataract surgery.