# HDL May Improve Ocular Tear Film Stability in Patients with Gastric Bypass: A Pilot Study

## TL;DR

This study suggests that high HDL levels may improve tear film stability in gastric bypass patients, potentially reducing evaporative dry eye symptoms.

## Contribution

The study introduces a novel correlation between blood lipid levels and tear film stability in post-gastric bypass patients.

## Key findings

- HDL positively correlates with tear break-up time (BUT) in gastric bypass patients.
- Triglycerides and cholesterol negatively correlate with Schirmer test results, indicating effects on aqueous tear production.
- Findings support the hypothesis that post-gastric bypass dry eye is primarily evaporative, not aqueous-deficient.

## Abstract

Most people with obesity who have undergone gastric bypass surgery have dyslipidemia. Because tear film layers play a major role in the pathogenesis of evaporative dry eye, some studies suggest that dry eye syndrome (DES) and dyslipidemia could cooperate in the ocular system. This study aimed to investigate whether tear film conditions are correlated with blood lipid levels. We calculated a sample of 29 patients in this study. We measured the characteristics of the tear film via the Schirmer test and tear break-up time (BUT) test; three measurements were made, and the average value was subsequently recorded. High-density lipoprotein (HDL) correlated positively with BUT (p < 0.05), but cholesterol and triglycerides correlated negatively with Schirmer (p < 0.05 and p < 0.001, respectively). Our findings suggest that HDL levels significantly influence ocular tear film stability and that triglycerides and cholesterol influence the aqueous component of the tear film, which is conducive to the hypothesis that postgastric bypass surgery tear deficiencies could be mainly of evaporative origin and not watery. Bariatric patients may have a high likelihood of suffering dry eye by modifications in the lipid tear layer; however, the development of DES in bariatric patients remains unclear. Thus, high levels of cholesterol and triglycerides could be associated with aqueous-type dry eye (main gland production), and low HDL levels could be associated with evaporative-type dry eye (meibomian gland production).