Development and validation of a new photographic scale to grade lid wiper epitheliopathy

Lid wiper epitheliopathy (LWE) is a clinical sign that has been associated with dry eye disease (DED) and contact lens discomfort (CLD). This study describes the development, validation and graders' preference of a new photographic scale for LWE, the Photographic Lid Wiper Epitheliopathy (PLWE) scale.

The PLWE grading scale was developed using LWE images selected from 57 screened patients (≥18 years of age) with confirmed LWE in both eyes. To validate the PLWE scale, a set including 20 images showing varying degrees of LWE from none to severe was chosen. To assess grading validity and grading reliability, observers were asked to grade the selected images using the PLWE and another commonly used subjective LWE grading protocol (Korb) on two separate sessions.

The mean grade (±SD) of all images was not statistically significant different between the PLWE scale (1.55 ± 0.44) and the alternative grading scale (Korb, 1.47 ± 0.54) (ANOVA F1, p > 0.05). The average difference from the mean of all graders was 0.03 ± 0.53 using the PLWE scale and 0.06 ± 0.57 when using the Korb protocol (ANOVA F1, p > 0.05). The Coefficient of Repeatability was 1.04 and 1.12 for the PLWE and Korb scales (p > 0.05). Ninety-five percent of the graders found PLWE easier to use than Korb and the same percentage would consider using the PLWE scale in clinical practice.

The format of the PLWE is similar to other anterior segment visual grading scales and this study revealed an ease of use preference for employing the PLWE by the graders. The presence of LWE has been associated with DED and CLD, and the addition of this new photographic scale could facilitate clinical judgement and record keeping of LWE in clinical practice.