SOME BLOOD-PLASMA CONSTITUENTS CORRELATE WITH HUMAN CATARACT

Aims-To look for differences between matched pairs of patients and con trols in concentrations of various plasma constituents which might ind icate dysfunctions associated with cataract. Method-One thousand patie nts were taken from the cataract waiting list of a specialist eye hosp ital. For each patient a matched control of the same sex and half-deca de of age but without cataract was taken fron the patient list of the family doctor of the patient; the control was the next alphabetically after the patient on the doctor's list. The patients and controls were visited in their homes by a team of nurses who performed venepuncture s and collected information for a questionnaire. Eye examinations were performed by a team of ophthalmologists. Results-Significant differen ces were found between the cataract and control groups in 10 of the 18 examined plasma constituents. A constellation of three - bilirubin, a lkaline phosphatase, and gamma glutamyl transpeptidase - was significa ntly higher in the cataract group, suggesting subclinical liver dysfun ction as a risk factor. Steroid treatment and diabetes increased catar act risk. Endogenous basal plasma cortisol levels were raised in the c ataract group, irrespective of steroid use and diabetic status. Alkali ne phosphatase, calcium, glucose, and sodium were all raised in the ca taract group. Given the raised total protein and albumin also found in the cataract group, the lower albumin/(total protein-albumin) ratio ( an approximation for albumin/globulin ratio) may imply an increase in globulin, suggestive of possible (chronic) infection. Total cholestero l was lower in the cataract group. Conclusion-Human groups seems to be due to an accumulation of risk factors, even if individual mean conce ntrations are well within normal limits but, of course, differing sign ificantly from the corresponding means in the control population.