Volume : 2
Issue : 2
Online ISSN : 2581-5016
Print ISSN : 2581-5024
Article First Page : 90
Article End Page : 94
Introduction: Many systemic autoimmune diseases are associated with dry eye; the autoimmune thyroid diseases are among them. One of the leading causes of ocular surface damage in thyroid associated orbitopathy (TAO) is dry eye syndrome (DES).
Aim: To evaluate the incidence and risk factors of dry eye and associated conjunctival morphological changes in TAO.
Materials and Methods: This is a cross sectional, non-interventional, non-comparative, observational study includes thirty patients (60 eyes) of clinically diagnosed TAO. The tear film and ocular surface were evaluated using the Schirmer- I test, Tear film break-up time (TBUT), Lissamine green staining and conjunctival impression cytology.
Results: Dry eye were found in 35 (58%) eyes based on dry eye severity grading scheme (DEWS). Positive vital staining with Lissamine green was observed in 36 (60.0%) eyes. The average degree of staining was 4.28±3.81 (National Eye Institute Workshop grading system). The abnormal impression cytology was observed in 30 eyes (50.0%) of 18 patients. Impression cytology revealed the following changes: significant epithelial dystrophy with cell polymorphism, goblet cells deficiency or absence, excessive desquamation and epithelial keratinization with local leukocytic infiltration.
Conclusion: Significant risk factors of ocular surface damage in TAO were exophthalmos, palpebral fissure height, upper lid retraction, lower lid retraction and lagophthalmos. Histopathologic changes detected in conjunctiva are consistent with dry eye but were not specific for TAO.
Keywords: Dry Eye Syndrome, Impression cytology, Lissamine Green staining, Thyroid Associated Orbitopathy