Correlation Study of Serum Zinc Concentration and Retina Layer Thickness in Hypertensive Patients

Objective: The aim of our study was to evaluate whether blood serum zinc concentration correlates with the thickness of human retina layers, in hypertensive patients with microvascular damage.
Methods: Retinas of elderly patients with arterial hypertension and microvascular damage were imaged using a swept-source ocular coherence tomography from Topcon. Automatic retinal segmentation was applied on a 6mm X 6mm scan protocol and average thickness for 5 examined layers was used for statistical analysis. Serum zinc concentration was measured using the Zinc Assay kit from Sentinel Diagnostics in a spectrophotometric method.
Results: The average age of the twenty-three enrolled patients was 70 years, varying between 62 and 76. The mean zinc value was 9.9 µmol/l ±1.62 (SD). All five examined layers of the retina presented inverse correlation with serum zinc concentration. The complex including the inner plexiform layer and ganglion cell layer indicated the Spearman’s (rho) correlation coefficient -0.42 and a significance level of p=0.04. Patients in high-Zn group (≥ 9.87 µmol/l) had thinner macular retina layers, most importantly in the inner-plexiform layer-ganglion cell layer complex (p=0.006).
Conclusions: Our study has found that serum zinc concentration is inversely correlated with the thickness of retina layers with statistical relevancy in the inner plexiform layer – ganglion cell layer complex. This finding emerges experimental studies in order to elucidate its clinical significance and to evaluate whether the fine architecture of the inner retina has the potential to benefit from oral zinc supplementation through modulating serum levels of zinc in patients with microvascular-damaging diseases.