Higher Levels of Serum Ionic Calcium are Associated with Macular Edema in Patients with Diabetic Retinopathy.

BACKGROUND: The aim was to study the association of serum total calcium, ionic calcium, and magnesium with increases in macular thickness parameters and photoreceptor ellipsoid zone (EZ) disruption in diabetic macular edema (DME). METHODS: This study is a tertiary care center based observational cross-sectional study with sixty-six consecutive cases, divided into 3 groups of 22 cases each with no diabetic retinopathy (No DR), non-proliferative diabetic retinopathy (NPDR), and proliferative diabetic retinopathy (PDR) and a control group of 22 healthy controls. Best corrected visual acuity (BCVA) was measured on logMAR scale. Central subfield thickness (CST), cube average thickness (CAT), and EZ disruption were assessed using spectral-domain optical coherence tomography (SD-OCT). Serum total calcium, ionic calcium, and magnesium were measured using standard protocol. Data was analyzed statistically. RESULTS: Significant correlation was found between the increase in CST and the increase in serum total calcium and serum ionic calcium. Increase in CAT was significantly correlated with an increase in serum total calcium, serum ionic calcium, and a decrease in serum magnesium. Grades of EZ disruption and logMAR BCVA were also found to be significantly positively associated with serum total calcium and ionic calcium and negatively with serum magnesium. CONCLUSIONS: Increased levels of serum ionic calcium and decreased levels of serum magnesium are associated with an increase in macular thickness and EZ disruption in DME.

Hyperglycemia potentiates the effect of ionic calcium in photoreceptor ellipsoid zone disruption in diabetic retinopathy.

PURPOSE: To study the association of serum ionic calcium and glycated hemoglobin (HbA1c) with retinal photoreceptor ellipsoid zone (EZ) disruption in diabetic retinopathy (DR). METHODS: This is a tertiary care center-based observational cross-sectional study. Sixty-three consecutive cases, divided into 21 cases each with no diabetic retinopathy, non-proliferative diabetic retinopathy and proliferative diabetic retinopathy were included. Twenty-one healthy controls were also included. Ellipsoid zone disruption was assessed using spectral-domain optical coherence tomography. Serum ionic calcium and HbA1c were measured using standard protocol. Patient data from cases were divided into two groups according to their HbA1c levels: group 1 (HbA1c < 7, n = 26) and group 2 (HbA1c > 7, n = 37). Data were analyzed statistically. RESULTS: Mean ionic calcium levels in group 1 and group 2 were 1.131 ± 0.073 mmol/dL and 1.170 ± 0.070 mmol/dL, respectively. In group 1, 11 out of 26 had EZ disruption (42.3%). Similarly, in group 2, 29 out of 37 had EZ disruption (78.4%). On logistic regression analysis, as compared to group 1, ellipsoid zone disruption was found to be positively associated with serum ionic calcium (p = 0.01) in group 2 cases. CONCLUSION: Increased levels of serum ionic calcium are associated with increased EZ disruption in patients with HbA1c > 7 in DR.

Retinal photoreceptor apoptosis is associated with impaired serum ionized calcium homeostasis in diabetic retinopathy: An in-vivo analysis.

PURPOSE: The aim of this work was to study the association of serum ionized calcium with retinal photoreceptor apoptosis on spectral domain optical coherence tomography (SD-OCT) in diabetic retinopathy (DR). METHODS: Sixty consecutive cases with Type 2 diabetes mellitus were categorized into three groups: no diabetic retinopathy; non-proliferative DR; proliferative DR. The eye with more severe form of the disease was considered. Twenty healthy controls were also included. Best corrected visual acuity (BCVA) was measured on logMAR scale. Retinal photoreceptor apoptosis was defined as disruption of retinal photoreceptor ellipsoid zone (EZ). Ellipsoid zone disruption was assessed using SD-OCT. Serum levels of total and ionized calcium were measured using standard protocol. RESULTS: EZ disruption was found to be positively associated with serum total calcium and ionized calcium. Also, EZ disruption was found to be positively associated with logMAR BCVA. CONCLUSION: Increased serum ionized calcium induces retinal photoreceptor apoptosis resulting in increased EZ disruption in DR.