Abstract
Purpose :
Corneal fluorescein staining (CFS) is frequently an outcome for ocular surface disease trials. The purpose of this investigation was to evaluate the intra- and inter-examiner repeatability of the Lexitas modified National Eye Institute (NEI) grading scale (Lexitas; 0-4 scale with half-point increments) in comparison to the original NEI grading scale (density-based scoring with 0-3 scale) and the dot count NEI grading scale (dot-count scoring with 0-3 scale).
Methods :
CFS illustrations were generated with Adobe Illustrator (n=18). Illustrations were created to cover the full range of possible grades. Illustrations were compiled into a PowerPoint with one illustration per slide. The 5 zone NEI grid was overlaid onto each illustration, and the relevant grading scale was added as a text box to each slide. Images were graded with all 3 NEI grading scales by 3 trained investigators with corneal grading experience to determine inter-examiner repeatability. The same trained investigators graded the same images in a different order but in the same manner about 2 weeks later to determine intra-examiner repeatability. Intra- and inter-examiner repeatability were evaluated with simple kappa statistics to assess exact agreement and weighted kappa statistics to assess partial agreement or association. Means across the 5 NEI zones were reported for each scale to understand overall performance.
Results :
The illustrations had mean ± SD intra-examiner simple kappa statistics of 0.67 ± 0.20, 0.91 ± 0.03, and 0.80 ± 0.20, and they had weighted kappa statistics of 0.72 ± 0.17, 0.94 ± 0.03, and 0.92 ± 0.08 for the NEI density, NEI dot count, and the Lexitas staining scales, respectively. The illustrations had a mean ± SD inter-examiner simple kappa statistics of 0.59 ± 0.06, 0.86 ± 0.03, and 0.78 ± 0.09, and they had weighted kappa statistics of 0.65 ± 0.05, 0.90 ± 0.02, and 0.91 ± 0.03 for the NEI density, NEI dot count, and the Lexitas staining scales, respectively.
Conclusions :
The Lexitas grading scale performed similarly or better than the original NEI and dot-count NEI grading scales, yet the expanded Lexitas grading scale may offer a better ability for analyzing ocular surface disease in trials compared to the less descriptive NEI grading scales.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.