Grading Contact Lens Complications: The Effect of Knowledge on Grading Accuracy

Abstract

Purpose: Grading contact lens complications is a time-effective process, which, if performed accurately, may improve patient management significantly. Multiple factors have been identified that influence grading accuracy, such as the knowledge, training, and experience of the observer. The aim of this study was to further explore the effect of knowledge on grading accuracy, both in terms of intensity and specificity, and to do so by avoiding the need to require the subjects to interpolate between whole number grades.Material and Methods: Optometry students were divided into three knowledge groups according to their academic progress and in such a way that knowledge intensity and specificity could be evaluated separately. A vertical visual analog scale was devised to allow subjects to grade three different conditions of medium severity (position 50 of the scale) from the Institute for Eye Research grading scale, mainly, bulbar hyperemia, limbal vascularization, and lid redness.Results: Bulbar hyperemia was graded lowest (mean = 21.5; SD = 1.4), followed by limbal vascularization (mean = 40.7; SD = 1.6) and lid redness (mean = 51.2; SD = 1.3), and these differences were found to be statistically significant (ANOVA, p = 0.000). Knowledge was found to influence the grading process, resulting in statistically significant differences in the overall grading performance of the three knowledge groups (ANOVA, p = 0.048). Furthermore, even if knowledge intensity failed to improve grading accuracy over a certain threshold, a combination of knowledge intensity and specificity resulted in an enhancement of the homogeneity of the grading data.Conclusions: Knowledge intensity and specificity both contribute to improve grading skills, albeit through different mechanisms. An intermediate knowledge of contact lens complications is required to attain good grading accuracy, and a basic training in pathology is also advised.