Serum Electrolytes in Cataract Patients with and without Diabetes Mellitus

Introduction: Cataract is the most common cause of blindness which is treatable. Though there are multiple risk factors involved, exact pathogenesis of cataract is yet to be established. Diabetics are known to be associated with electrolyte disturbances, like hypo/hypernatremia, hyperkalemia. We hypothesize that serum electrolytes may be altered in diabetic cataract patients. The aim of the study was to compare serum electrolytes in diabetic and non-diabetic cataract patients as well as to assess the correlation of duration of diabetes with electrolytes as well as risk of cataractogenesis in diabetics.

Methods: The cross sectional prospective study was conducted in Clinical Biochemistry, IGMCRI, Puducherry. Blood samples of fifty each diabetic and non-diabetic cataract patients were analyzed for electrolytes using Roche electrolyte analyzer which works on the principle of ISE. Statistical analysis was done using SPSS version 21.Student’s unpaired ‘t’ test was used to compare the means of electrolytes, Pearson’s correlation coefficient was calculated to find the correlation between duration of diabetes and electrolytes. Odd’s ratio was calculated to study the association between electrolytes and the risk of cataractogenesis.

Results: We observed a significantly higher serum sodium (3.3%), potassium (10.2%) and chloride levels (2.8%) [(P<0.001), (P<0.05) and (P<0.01) respectively] in diabetic cataract patients as compared to non-diabetics. Elevation of sodium, potassium and chloride pose 3.45, 1.76, 1.36 times respectively higher risk of cataractogenesis in diabetics. Sodium and potassium levels were positively correlated with duration of diabetes (r= 0.452, p<0.01 and r= 0.349, P<0.05 respectively).

Conclusion: Alterations in electrolytes pose an added risk of cataract formation in diabetics in addition to hyperglycemia. Along with carbohydrate restricted diet, salt restriction may help in prolonging cataract formation as well as progression.