[Accuracy of intraocular power calculation formulas].
OBJECTIVE
We examined the accuracy of intraocular lens power calculation formulas, with special emphasis on the prediction of refraction in different axial lengths.


METHODS
786 cases were subdivided into four groups based on the axial length (short axial length < 22.0 mm, normal axial length = 22-24.4 mm, mid-range axial length = 24.5-26.9 mm and long axial length > 27 mm). Seven different formulas (Holladay, SRK, SRK II, SRK/T, S-SRK, M-SRK, L-SRK) were tested for their accuracy in predicting post-operative refraction.


RESULTS
The best results were obtained using the S-SRK formula in the short axial length group (n = 114), The SRK and Holladay formulas in the normal axial length group (n = 278). The Holladay and SRK/T formulas in the mid-range axial length group (n = 135), and the SRK/T and L-SRK in the long axial length group (n = 259).


CONCLUSIONS
Our results emphasize the importance of using an intraocular lens formula specific for each range of axial length when calculating the predicted refraction.
Kozawa Eye Hospital, Mito, Japan.
T
T
Kijima
T
T
Kozawa
Y
Y
Kora
S
S
Yaguchi
M
M
Inatomi
R
R
Koide
T
T
Ozawa
D000368:Aged; D005260:Female; D006801:Humans; D007910:Lenses, Intraocular; D008297:Male; D008722:Methods; D008875:Middle Aged; D012029:Refraction, Ocular