Patients with hypothyroidism have mixed dry eye due to tear film instability, but do not exhibit epithelial cell damage, according to a study published in Archivos de la Sociedad Española de Oftalmología.
Researchers included 59 patients with hypothyroidism and dry eye (86.4% women; mean age, 59.6 years) in an observational, cross-sectional study. All participants except for 1 were treated with levothyroxine. All patients underwent osmolarity testing, meniscometry, Schirmer type 1 test, noninvasive breakup testing (NiBUT), and lissamine green staining and reported dry eye symptomatology using the Ocular Surface Disease Index (OSDI) questionnaire.
According to the report, the mean OSDI score was 31.63, with 86.44% of patients reporting moderate to severe symptomatology. Schirmer I and NiBUT assessments were most likely to reveal higher dry eye severity with mean scores of 12.01 mm and 8.05 seconds, respectively. Both assessments revealed moderate to severe disease severity in 79.66% of participants.
Lacrimal meniscus height and lissamine green testing, however, showed the lowest positivity of all tests, with 37.2% and 32.20% of participants exhibiting moderate to severe symptomatology, respectively. Lissamine green staining showed the highest tendency towards normality (67.80% negative).
Researchers highlight the connection between hypothyroidism and dry eye disease and state, “the autoimmune process may give rise to inflammatory events on the ocular surface, particularly the conjunctiva, and lead to tear hyperosmolarity due to evaporation from a reduced aqueous reservoir.”
Study limitations include a single center design.
Caycedo Lozano AR, Arias Ortiz WA, Martín V, Ramírez S, Medina Siervo CA. Analysis of diagnostic tests in patients with dry eye and hypothyroidism: an observational study. Arch Soc Esp Oftalmol (Engl Ed). Published online September 13, 2022. doi:10.1016/j.oftale.2022.03.015