Abstract
Purpose :
The Omega-3 Index is a measure of systemic levels of long-chain omega-3 fatty acids (FAs), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). The aim of this cross-sectional study was to investigate whether an association exists between the Omega-3 Index and corneal nerve structural parameters, in healthy controls and those with diabetes.
Methods :
Participants with diabetes and no or mild peripheral neuropathy symptoms (n=26), and age- and sex-matched controls (n=21), underwent systemic FA analysis and comprehensive ocular surface assessments. Corneal sub-basal nerve structure was assessed by in vivo confocal microscopy and quantified with automated software. Corneal sensitivity was measured with non-contact esthesiometry. The relationship between systemic FA levels and corneal nerve parameters was evaluated using multiple linear regression (MLR), adjusted for age, sex, neuropathy symptom score, and the presence of both diabetes and dry eye disease (according to TFOS DEWS II criteria).
Results :
The Omega-3 Index was similar in both groups (median [IQR]; control vs diabetes: 5.54% [4.54–6.06] vs 5.00% [4.25–5.68]; p=0.32). Corneal nerve fibre length (CNFL) was higher in the control group than in the diabetes group (mean ± SD: 14.71 ± 2.99 mm/mm2 vs 12.60 ± 3.41 mm/mm2; p=0.03). Using MLR modelling, Omega-3 Index (b=0.33; p=0.02), age (b=-0.46; p=0.001) and diabetes (b=-0.30; p=0.03) were significant factors associated with CNFL (R2=0.39, F=4.22; p=0.002). In a separate model, DHA (b=0.32; p=0.027) and age (b=-0.41; p=0.003) were associated with CNFL (R2=0.37, F=3.99; p=0.003). Neither EPA nor omega-6 levels were related to CNFL. There was no association between systemic FA levels and corneal sensitivity in either group.
Conclusions :
This study newly describes a relationship between systemic Omega-3 Index and CNFL, the major anatomical feature of the corneal sub-basal nerve plexus.
This is a 2021 ARVO Annual Meeting abstract.