The Effect of Magnesium on Retinal Venous Pressure of Patients with Normal-Tension Glaucoma and Flammer Syndrome

Abstract

# Purpose To measure the retinal venous pressure (RVP) in both eyes of patients with normal-tension glaucoma (NTG) and Flammer Syndrome before and 6 weeks after treatment with magnesium. # Methods This retrospective study included 30 patients with NTG and Flammer-Syndrome who were treated with magnesium (12 mmol daily). RVP (mmHg) was measured in all patients bilaterally at baseline and six weeks later using contact lens ophthalmodynamometry. Ophthalmodynamometry was performed by applying increasing pressure on the eye via a contact lens. The minimum force required to induce a venous pulsation is called ophthalmodynamometric force (ODF). The RVP is defined and calculated as the sum of ODF and intraocular pressure (IOP) \[RVP = ODF + IOP\]. # Results Out of the 30 NTG patients included, 16 were male (53%) and 14 were female (47%). There was no difference in IOP before and 6 weeks after magnesium intake but there was a significant decrease in RPV of 2.15 (95% CI: 1.68--2.62). # Conclusions Treatment with magnesium may decrease RVP in both eyes of NTG patients with Flammer Syndrome. This effect could be due to the partial inhibition of endothelin-1 (ET-1) by magnesium.