• Tear function tests were performed on 30 Australian Aborigines, and the results obtained were compared with the results obtained in 101 mildly hypertensive Europeans. Aborigines had a significant abnormality in tear break-up time, which may be related to conjunctival scarring caused by trachoma. The tests used failed to show any tear film abnormalities associated with the presence of either pterygium or climatic droplet keratopathy other than a discontinuity of the marginal tear strip, which is probably a secondary phenomenon. It seems unlikely that either pterygium or climatic droplet keratopathy is caused by a gross abnormality of the tear film.
Taylor HR. Studies on the Tear Film in Climatic Droplet Keratopathy and Pterygium. Arch Ophthalmol. 1980;98(1):86-88. doi:10.1001/archopht.1980.01020030088005