Corneal Nerve Health Influenced by Systemic Omega-3 Levels

Omega-3 fatty acid levels are independently associated with several corneal nerve parameters, suggesting they may influence corneal nerve structure, according to research published in Eye. 

Researchers included 47 participants (median age, 48 years; 63% women) with (n=26) and without diabetes (n=21) in a prospective, cross-sectional analysis which sought to determine associations between systemic omega-3 fatty acid levels and corneal nerve structure and functioning. All participants underwent corneal staining, tear breakup time (TBUT) analysis, and tear osmolarity measurement. Patients completed the Ocular Surface Disease Index (OSDI) to report dry eye symptoms and received a dried blood spot test to assess systemic fatty acid profiles. A noncontact corneal esthesiometer evaluated corneal sensation.

Overall, participants had a mean omega-3 index of 5.2%. According to the report, omega-3 index (β, 0.33; P =.02), age (β, −0.46; P =.001), and diabetic status (β, −0.30; P =.03) were all associated with corneal nerve fiber length. Omega-3 index, age, and diabetic status were also significantly associated with corneal nerve fiber density (R², 0.36; P =.004) and docosahexaenoic acid (DHA) levels predicted corneal nerve fiber density. Neither eicosapentaenoic acid nor omega-6 fatty acid levels were associated with corneal nerve fiber length or density. 

“[T]his study found a positive association between the systemic Omega-3 Index and quantitative measures of corneal nerve architecture; this relationship was independent of age or diabetes status,” according to the study authors. “Increasing systemic omega-3 PUFA, particularly DHA, levels could be beneficial for corneal nerves.”

Study limitations include a small sample size and single center design.