Impact of Dyslipidemia on Tear Film and Meibomian Gland Dysfunction: A Cross-Sectional Study of the Interplay between Serum Lipid Profile and Ocular Surface Health

Purpose. To determine the relationship between dyslipidemia and dry eye disease (DED), as well as its influence on tear film and meibomian glands. Methods. This cross-sectional study included 40 patients with a mean age of 35.2 ± 13.9 years without any history of dyslipidemia. DED and serum lipid profile were evaluated after 8 hours of fasting. Patients were classified according to serum lipid levels with the following cut-off values: total cholesterol (TC) (200 mg/dl), high-density lipoprotein (HDL) (40 mg/dl), low-density lipoprotein (LDL) (130 mg/dl), and triglycerides (TG) (150 mg/dl). The relationship between serum lipid levels and DED was analyzed with the following variables: dry eye questionnaire-5 (DEQ-5), first (F-NIBUT) and average (A-NIBUT) noninvasive breakup time, tear meniscus height (TMH), lipid layer grade (LLG), conjunctival bulbar redness (CBR), and upper (U-LAMG) and lower (L-LAMG) loss area of meibomian glands. Results. Regarding tear film, patients with elevated TC and LDL levels reported significantly higher DEQ-5 scores and TMH ( <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" id="M1"><a:mi>P</a:mi><a:mo><</a:mo><a:mn>0.05</a:mn></a:math> ), while those with lower HDL levels showed significantly higher LLG ( <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" id="M2"><c:mi>p</c:mi><c:mo><</c:mo><c:mn>0.05</c:mn></c:math> ). Regarding MGD, patients with elevated TC, LDL, and TG, as well as lower HDL levels showed significantly higher L-LAMG ( <e:math xmlns:e="http://www.w3.org/1998/Math/MathML" id="M3"><e:mi>p</e:mi><e:mo><</e:mo><e:mn>0.05</e:mn></e:math> ). HDL was correlated with LLG ( <g:math xmlns:g="http://www.w3.org/1998/Math/MathML" id="M4"><g:mi>p</g:mi><g:mo><</g:mo><g:mn>0.05</g:mn></g:math> ), while TC was correlated with TMH ( <i:math xmlns:i="http://www.w3.org/1998/Math/MathML" id="M5"><i:mi>p</i:mi><i:mo><</i:mo><i:mn>0.05</i:mn></i:math> ) and L-LAMG ( <k:math xmlns:k="http://www.w3.org/1998/Math/MathML" id="M6"><k:mi>p</k:mi><k:mo><</k:mo><k:mn>0.05</k:mn></k:math> ), respectively. Conclusions. Disorders in TC, HDL, LDL, and TG levels were associated with DED, having an impact on the tear film and meibomian glands, specifically in DEQ-5 scores, LLG, and L-LAMG.