Table 3: Tear Osmolarity in Eyes with Pterygium vs. Controls.

Two studies used the TearLab osmometer, two studies used mucus fern testing, and one study used both the TearLab osmometer and Mucus Fern testing. Tear osmolarity was found to be statistically significantly higher in patients with pterygium vs. controls in five of the six evaluations. One study reported finding no difference in tear osmolarity between patients with pterygium vs. controls.

Year	Author	n = No. patients, No. eyes	Method	Results
2019	Safarzadeh et al.(14)	n = 95, 190	TearLab osmometer	Higher in pterygium†
2014	Ozsutcu et al.(23)	n = 65, 65	TearLab osmometer	Higher in pterygium†
2012	Julio et al.(27)	n = 30, 30	TearLab osmometer	Higher in pterygium†
2012	Julio et al.(27)	n = 30, 30	Mucus Fern	Higher in pterygium†
2001	Ergin et al.(32)	n = 84, 112	Mucus Fern	No difference
1998	Kadayifçilar et al.(33)	n = 70, 70	Mucus Fern	Higher in pterygium†

^†Statistically significant