Immersion A-scan compared with partial coherence interferometry: outcomes analysis.
OBJECTIVE
To compare 2 methods of axial length measurement, immersion ultrasonography and partial coherence interferometry, and to elucidate surgical outcomes based on immersion measurements.


METHODS
Oregon Eye Institute, Eugene, Oregon, USA.


METHODS
Axial length measurements in 50 cataractous eyes were obtained by optical biometry (IOLMaster, Zeiss Humphrey Systems) and immersion ultrasound (Axis II, Quantel Medical), and the results were compared. Intraocular lens (IOL) power calculations in the same eyes after cataract extraction and posterior chamber IOL implantation were evaluated retrospectively based on the postoperative spherical equivalent prediction error.


RESULTS
Immersion ultrasonography and partial coherence interferometry measurements correlated in a highly positive manner (correlation coefficient = 0.996). Outcomes analysis demonstrated 92.0% of eyes were within +/-0.5 diopter of emmetropia based on immersion axial length measurements.


CONCLUSIONS
Immersion ultrasonography provided highly accurate axial length measurements and permitted highly accurate IOL power calculations.
Packer
Mark
M
Oregon Eye Institute, Eugene, Oregon, USA.
Fine
I Howard
IH
Hoffman
Richard S
RS
Coffman
Peggy G
PG
Brown
Laurie K
LK
D001699:Biometry / Q000379:methods*; D003941:Diagnostic Techniques, Ophthalmological; D005123:Eye / Q000000981:diagnostic imaging / Q000473:pathology*; D006801:Humans; D007368:Interferometry / Q000379:methods*; D019654:Lens Implantation, Intraocular; D007910:Lenses, Intraocular; D008027:Light; D017063:Outcome Assessment, Health Care; D018918:Phacoemulsification; D012029:Refraction, Ocular; D012030:Refractive Errors / Q000175:diagnosis* / Q000000981:diagnostic imaging; D015203:Reproducibility of Results; D012189:Retrospective Studies; D014463:Ultrasonography