Accuracy in determining intraocular lens dioptric power assessed by interlaboratory tests.
OBJECTIVE
To describe a testing program conducted by a standards group as a guide for setting international tolerances for intraocular lens (IOL) dioptric power.


METHODS
Multicenter study.


METHODS
Seven biconvex, poly(methyl methacrylate) IOLs ranging in power from 10.00 through 30.00 diopter (D) were circulated among nine participating laboratories experienced in IOL optical measurements. Each laboratory performed repeated optical tests to determine dioptric power. These results were analyzed for repeatability and reproducibility in accordance with methods specified by the International Organization for Standardization.


RESULTS
Intralaboratory repeatability was less than 0.5% of the dioptric power, and interlaboratory reproducibility, when following a normalized procedure for correction and conversion, was less than 1.0% of the dioptric power.


CONCLUSIONS
Tolerance limits of +/0 0.30 D in the range 0 to 15.00 D, +/- 0.40 D for 15.50 to 25.00 D, and +/- 0.50 D for 25.50 to 30.00 D have been proposed as an international standard for IOLs. The contribution of IOL power error within the limits of the standard are estimated to contribute less than 1.0% to the total error in postoperative refractive prediction.
Norrby
N E
NE
Pharmacia Production BV, Groningen, The Netherlands.
Grossman
L W
LW
Geraghty
E P
EP
Kreiner
C F
CF
Mihori
M
M
Patel
A S
AS
Portney
V
V
Silberman
D M
DM
D007910:Lenses, Intraocular / Q000592:standards*; D008768:Methylmethacrylates; D009885:Ophthalmology / Q000379:methods*; D055095:Optics and Photonics; D015203:Reproducibility of Results
D008768:Methylmethacrylates