The combined influence of knowledge, training and experience when grading contact lens complications

A study was conducted to evaluate the influence of knowledge, training and experience (clinical skills set) when assessing the severity of contact lens complications.

Nine optometrists (who were in possession of a relevant clinical skills set) and nine 'non-optometrists' (subjects without the clinical skills set) were each invited to grade - to the nearest 0.1 increment - an image of each of 16 contact lens complications using Efron Grading Scales for Contact Lens Complications. This procedure was repeated 2 weeks later, yielding a total data base comprising 576 individual grading estimates.

The mean of the test and retest grading estimates was the same for the optometrists (2.8 +/- 0.7) and the non-optometrists (2.6 +/- 0.9) (F1,15,1 = 1.3, p = 0.26); that is, non-optometrists can grade accurately. Median grading reliability for optometrists (+/-0.41) was lower than (i.e. superior to) that for non-optometrists (+/-0.67) (p = 0.001). Non-optometrists tended to display a reluctance to grade by interpolation and to less reliably grade subtle clinical signs.

When averaged over several attempts, non-optometrists will arrive at similar estimates of severity to optometrists when grading ocular complications of contact lens wear; however, they will do so less reliably. The relative contribution of the three attributes of the clinical skills set to grading performance is presently unclear.