How Reliable is the Lacrimal Scintigraphy Report An Inter- And Intra-Observer Agreement Study

Purpose: To assess the inter- and intra-observer agreement for lacrimal scintigraphy (LS) reports with and without considering the irrigation test results Methods: In a prospective, observational, cross sectional study, two masked clinicians (lacrimal surgeon and nuclear medicine specialist) independently reported 100 LS images (50 patients of > 6 years of age with unilateral anophthalmic socket) in a university hospital. The lacrimal surgeon performed a diagnostic irrigation test and repeated the report of the same LS images 2 years after the first report (intra-observer agreement). A weighted Kappa analysis was performed to determine inter- and intra-observer agreement for the type (normal, partial and complete obstruction) and location (presac, preduct, and intraduct) of the obstruction. Subgroup analysis was also performed with consideration of irrigation test results. Results: A significantly moderate agreement was found between lacrimal surgeon and nuclear medicine specialist for both the type (Kappa=0.55) and location (Kappa=0.48) of obstruction. Agreement values improved for both the type (kappa=0.61) and location (Kappa=0.56) of obstruction in cases with normal irrigation test. It, however, decreased in cases with abnormal irrigation test (Kappa=0.41 for the type and 0.31 for the location of obstruction). Strong and significant intra-observer (lacrimal surgeon) agreement was found for both the type (Kappa=0.66) and location (Kappa=0.69) of obstruction. LS and irrigation tests showed no to slight agreement. Conclusion: moderate agreement was found between lacrimal surgeon and nuclear medicine specialist regarding the interpretation of LS which decreased in cases with abnormal irrigation test. Intra-observer agreement was strong for the lacrimal surgeon.