Abstract
IOL power is the factor determining postoperative refraction of cataract. Whether it can be calculated with accuracy relies on the results of the surgery. To calculate the IOL power, the axial length must be measured. We must measure it accurately to predict the accuracy postoperative refraction, because it is said that postoperative refractive errors are effected by errors in the measurement of the axial length.
It is said that errors in the measurement of the axial length are caused by lack of skill in the examiners and the patient's poor fixation. We evaluated the following factors: preoperative visual acuity, preoperative refraction, difference between right and left axial length, and keratometer reading.
We compared the case where the actual postoperative refraction exceeded the predicted one by 1.0D within a deviation of ±1.0D. As a result, cases where the preoperative visual acuity is under 0.1, preoperative refraction is greater than -3.0D, and the difference between right and left greater than 0.3mm form a high percentage of the postoperative refractive errors greater than 1.0D. We must measure the axial length with accuracy, taking the patient's factors caused by errors in measurement of the axial length into consideration, in order to achieve an accurate result.
