Tear film breakup patterns in patients with thyroid eye disease appear to be different than those found in individuals with dry eye alone, new research published in Scientific Reports suggests.

The prospective observational study examined tear breakup patterns in 154 eyes of 78 Japanese patients with thyroid eye disease who met the diagnostic criteria for dry eye in Japan. Breakup patterns were classified as area, line, spot, dimple and random breaks.

The incidence of each breakup pattern was similar in patients with simple dry eye without thyroid eye disease. On the other hand, among those with the condition, line breaks were the most frequently observed pattern (52%), followed by random (23%), spot (19%) and dimple breaks (7%). No eyes showed area breaks, which is the most severe manifestation of aqueous-deficient dry eye, the investigators noted.

These findings indicate that thyroid eye disease frequently induces aqueous-deficient dry eye, probably due to lacrimal gland involvement, the researchers noted. However, it was found to be relatively mild, they added.

Additionally, while random breaks in simple dry eye were generally associated with only minor ocular surface damage, those found in thyroid eye disease patients were tied to a higher rate of concomitant superior limbic keratoconjunctivitis.

Also of note, patients with moderate-to-severe thyroid eye disease had wider palpebral fissure heights, more proptotic eyes and a higher incidence of lagophthalmos, resulting in more tear evaporation. However, the severity of thyroid eye disease was not associated with tear film breakup pattern.