T. Olsen et al., INTRAOCULAR-LENS POWER CALCULATION WITH AN IMPROVED ANTERIOR-CHAMBER DEPTH PREDICTION ALGORITHM, Journal of cataract and refractive surgery, 21(3), 1995, pp. 313-319
The accuracy of intraocular lens (IOL) power calculation was evaluated
in a multicenter study of 822 IOL implantations using the Binkhorst I
I, Sanders/ Retzlaff/Kraff (SRK I (TM), SRK II (TM), SRK/T (TM), Holla
day, and Olsen formulas. All but the first of these were optimized in
retrospect with calculation of the SRK A-constant, the Holladay surgeo
n factor, and the Olsen pseudophakic anterior chamber depth (ACD) for
each lens style. The ACD prediction of the Olsen formula was based on
a previously described regression formula incorporating preoperative A
CD, corneal height, axial length, and lens thickness, Among the optica
l IOL power calculation formulas, the highest IOL power prediction err
or was found with Binkhorst's and the lowest with Olsen's, which was m
ore accurate than the SRK/T and the Holladay formulas (P <.05). The SR
K/T formula was significantly more accurate than the original SRK regr
ession formulas (P <.001), When analyzed for axial length dependence,
all formulas showed the least error in the normal range. Error of the
Olsen formula was lower than that of the others in the axial length in
terval 20 mm to 26 mm. No differences in accuracy were found between t
he optical IOL calculation formulas in eyes with an axial length above
26 mm (P<.05). The accuracy of IOL power calculation can be improved
with optical formulas using newer-generation ACD-prediction algorithms
.