Impact of clinico-biochemical variations on the etiopathogenesis of cataract: a case-control study

PURPOSE: Cataract is a major cause of blindness worldwide with a greater prevalence in developing countries like India. Owing to speculations about the relationship of various biochemical markers and cataract formation this case-control study was designed with the aim to know the impact of serum blood sugar, serum electrolytes and serum calcium on the etiopathogenesis of cataract in Kashmiri population. METHODS: A total of 300 cases diagnosed with cataract and 360 healthy controls were taken for the study. Serum of all the cases and controls was analyzed for blood sugar and calcium using spectrometric techniques. Sodium and potassium were analyzed using Ion-Selective Electrode technology. All the investigations were done on ABBOTT c4000 fully automatic clinical chemistry analyzer. RESULTS: Most of the patients in our study were ≥50 years of age having posterior subcapsular cataract. The mean levels of serum fasting blood sugar (mg/dL), serum sodium (mmol/L), serum potassium (mmol/L) and serum calcium (mg/dL) were 99.4 ± 7.7; 140.4 ± 2.5; 4.2 ± 0.5; and 8.9 ± 0.5, respectively, in cases compared to 107.7 ± 12.3; 142.9 ± 5.0; 3.8 ± 0.5; and 8.3 ± 1.7, respectively, in healthy controls. A significantly higher number of cataract cases had elevated serum glucose and sodium levels, low serum potassium and calcium levels compared to healthy controls. CONCLUSIONS: Hyperglycemia, hypernatremia, hypokalemia and hypocalcemia can independently increase the patients’ risk to cataracts. Corrections in these biochemical parameters may reduce cataract incidence.