Aim: This study was conducted to determine the level of inter-observer agreement in the modified grading scheme for trichiasis of the upper eyelid.
Methods: A grading system that covers the entire spectrum of trachomatous trichiasis, extending from the simple to the severe forms, was initially developed by the first and second authors and field-tested. The grading scheme recognizes three levels of severity, based on deviation of the lid margin (TT1, TT2 and TT3); and four anatomical locations indicating where the eyelashes touch the globe in TT1 (nasal, central, temporal, or combined). The grading of trichiasis patients was then conducted on the basis of the modified grading scheme.
Results: The inter-observer agreement between the grades of simple trichiasis (TT1) and entropion (TT2) using Cronbach's alpha was 0.84, and the agreement within each sub-grade was 0.86. The weighted Kappa value was 0.68 (95% CI 0.57-0.79) for the main grades and 0.49 (95% CI 0.23-0.79) for the sub-grades.
Conclusions: The inter-observer agreement was very reliable and could easily be attained by all levels of ophthalmic professionals. As the grading follows the natural progression of trichiasis from the simple to the severe forms in relation to the anatomical site involved, it helps to determine the degree of correction and how far to extend the surgical incision.