The ocular research community has noted several differences between Asian and Caucasian eyes, including a predisposition for dry eye in Asian eyes.1 However, a new study re-evaluating that view suggests that the difference has more to do with environment than ethnicity. The studies that pointed to an ethnic difference were “compounded by the fact that the comparison was done on subjects living in different environments,” according to newly published research in Contact Lens & Anterior Eye.2
The investigators measured the tear film break-up time (TBUT), non-invasive TBUT (NTBUT) and tear meniscus height (TMH) of 88 asymptomatic patients—12 Asian Americans, 23 Caucasian Americans and an additional 53 Chinese nationals. To isolate the effect of ethnicity, the results of 12 Asian Americans were compared with the 23 Caucasian Americans. Then, the same 12 Asian Americans’ results were compared with the 53 Chinese subjects. The tear film stability did not show any significant difference among Asian American and Caucasian subjects. However, the tear film stability of the Asian American group was significantly superior to that of the Chinese group in TBUT, NTBUT and TMH.2
1. Craig J, Lim J, Han A, et al. Ethnic differences between the Asian and Caucasian ocular surface: a co-located adult migrant population cohort study. Ocul Surf. September 22, 2018. [Epub ahead of print].
2. Wang H, Seger K, Yang S, Xing X. The role of ethnicity versus environment in tear film stability: a pilot study. Contact Lens Anterior Eye. May 6, 2019. [Epub ahead of print].