Omega-3 fatty acids supplements for dry eye - Are they effective or ineffective?

Abstract

Purpose: To evaluate effectiveness of omega-3 fatty acid supplements in relieving dry eye symptoms and signs in symptomatic visual display terminal users (VDT).

Methods: A randomized controlled study was done; eyes of 470 VDT users were randomized to receive four capsules twice daily for 6 months (O3FAgroup), each containing 180 mg of eicosapentaenoic acid and 120 mg docosahexaenoic acid. The O3FA group was compared with another group (n = 480) who received four capsules of a placebo (olive oil) twice daily. Patients were evaluated at baseline, 1, 3, and 6 months, respectively. The primary outcome was improvement in omega-3 index (a measure of EPA and DHA ratio in RBC membrane). Secondary outcomes were improvement dry eye symptoms, Nelson grade on conjunctival impression cytology, Schirmer test values, tear film breakup time (TBUT), and tear film osmolarity. Means of groups (pre-treatment, 1, 3, and 6-months) were compared with repeated measure analysis of variance.

Results: At baseline, 81% patients had low omega-3 index. In the O3FA group, a significant increase in omega-3 index, improvement in symptoms, reduction in tear film osmolarity, and increase in Schirmer, TBUT, and goblet cell density was observed. These changes were not significant in the placebo group. Improvement in test parameters was significantly (P < 0.001) better in patients with low omega3 index (<4%) subgroup.

Conclusion: Dietary omega-3 fatty acids are effective for dry eye in VDT users; omega-3 index appears to be the predictor to identify potential dry eye patients who are likely to benefit from oral omega-3 dietary intervention.

Keywords: Goblet cell density; Omega-3 fatty acids; Omega-3 index; tear film osmolarity; visual display terminal users.

Figure 1

Flowchart showing patients’ enrolment, randomization, intervention, follow-up, and analysis

Figure 2

Photomicrograph of impression cytology specimen, stained with periodic acid-Schiff, and hematoxylin-eosin at X 400 with squamous metaplasia. Showing both normal cells (NC) and increased nuclear–cytoplasmic ratio (SM)

Figure 3

Line diagram showing mean change in omega-3 index, dry eye symptom score, Schirmer score, tear film breakup time, tear film osmolarity, goblet cell density, and Nelson grade between O3FA and placebo groups at baseline, 1 month, 3 months, and 6 months, respectively