AIM: To observe the location characteristics of the earliest tear film breakup in elderly patients with dry eyes.

METHODS: Cross-sectional study. The 154 elderly patients with dry eyes in our hospital from July 2019 to December 2019 were included, with 143 right eyes, 124 left eyes, and 71 patients were males, 83 patients were females, aged 68-90(mean: 73.40±4.13)years old. The location of the earliest tear film breakup was investigated by using corneal topographer. The cornea was separated to four sectors to record the earliest tear film breakup location by anticlockwise order. The sector corresponding to the right eye was nasal superior, temporal superior, temporal inferior and nasal inferior respectively. And it corresponding to the left eye was temporal superior, nasal superior, nasal inferior and temporal inferior respectively. Then the sector which was the earliest tear film breakup location was recorded. At the same time, the distance which was from the earliest tear film breakup location to the centre of cornea was recorded too.

RESULTS: The highest constituent ratio of area of right eye was nasal inferior(28.7%), then was temporal inferior(27.3%), nasal superior(20.3%), temporal superior(11.2%), and the constituent ratio of earliest tear film breakup occurred in 2-3 areas at the same time was 12.6%. The constituent ratio of the earliest tear film breakup area of left eye also was nasal inferior(31.5%), then was temporal inferior(25.0%), nasal superior(23.4%), temporal superior(11.3%), the constituent ratio of earliest tear film breakup occurred in 2-3 areas at the same time was 8.9%. There was no difference in the constituent ratio of tear film breakup area between two eyes(χ²=1.443, P=0.837). The distance from the earliest tear film breakup area of the nasal inferior quadrant to the centre of cornea was mostly the zone from 1.5-2mm and 2-2.5mm in both eyes.

CONCLUSION: There is a certain regularity in the characteristics of tear film breakup area in elderly patients with dry eyes, and the earliest tear film breakup area of both eyes is mainly occurred in nasal inferior, and there is no significant difference between two eyes.