Analysis about Diffe rences of Preoperative Measurement of Strabismic Angle in Exodeviation

ABSTRACT

Preoperarive measurement of strabismic angle is most important procedure in determining the amount of surgery.But measured angles are not always the same at each examination, which is quite a steress to both the operator and the patient because additional examination has to be done for accurate determination of surgical amount and also because the confidence for planned amount of surgery may be reduced.Therefore we investigated the variance of preoperative measurements and evaluated the necessity of repeated examinations. We compared the variance of measurement and investigated the bias and reliability of repeated examinations, from 104 patients who were examined initially by a resident at first visit and examined repeatedly at least 3 times before operation by a specialist.Also, the degree of variance in measurement and its relation with postoperative result were evaluated. The differences in measurement between resident and specialist was average 2.37 prism diopters, which was not significant on reliability analysis.Also, there were no significant differneces among 3 measurements by specialist. The degree of variance decreased with increasing age and the larger the degree of variance in measurement, the larger the deviation which may be remained postoperatively. The results suggest that the angle of deviation measured by resident is reliable and repeated measurements do not differ significantly[p>0.05], and also confirms that the variation of these measurements is an important factor which can influence postoperative results.