Scheimpflug imaging to determine intraocular lens power in vivo.
OBJECTIVE
To assess the feasibility of determining intraocular lens (IOL) power by measurement of the central optic thickness using clinically available Scheimpflug imaging (Pentacam, Oculus).


METHODS
King's College Hospital Ophthalmology Department, London, United Kingdom.


METHODS
Sixty-seven eyes were assessed 1 month after uneventful phacoemulsification with in-the-bag implantation of AcrySof MA60AC IOLs (Alcon). The correlation between IOL thickness measurement and IOL power was calculated. Repeatability of central optic thickness measurement was determined from 10 successive scans of 4 patients.


RESULTS
Within-subject standard deviation increased with the subject mean. The coefficient of variability was 1.4%. Measured lens thickness was highly correlated with lens power (R(2) = 0.94, P<.001). Over the measured range, 95% confidence intervals varied between +/-0.83 diopters (D) and +/-0.92 D.


CONCLUSIONS
Central IOL thickness measurements with the Pentacam Scheimpflug camera were highly repeatable and closely correlated with the known IOL power. The IOL power, calculated from a regression equation, is likely to be less than +/-1.00 D away from the actual power. Approximate in vivo IOL power determination is feasible with clinically available Scheimpflug imaging. This could be applied clinically in cases of unexplained postoperative refractive error.
Turner
Stephen J
SJ
King's College Hospital Ophthalmology Department, King's College Hospital, London, United Kingdom. stove@doctors.org.uk
Lee
Edward J K
EJ
Hu
Victor
V
Hollick
Emma J
EJ
D000368:Aged; D000369:Aged, 80 and over; D003941:Diagnostic Techniques, Ophthalmological; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D019654:Lens Implantation, Intraocular; D007910:Lenses, Intraocular; D008297:Male; D008875:Middle Aged; D055095:Optics and Photonics; D018918:Phacoemulsification; D010781:Photography / Q000379:methods*; D011184:Postoperative Period; D015203:Reproducibility of Results