Lactate dehydrogenase level and protein pattern in the aqueous humour of patients with retinoblastoma.

The diagnostic significance of the lactate dehydrogenase (LDH) level and the protein pattern in the aqueous humour was evaluated in patients with retinoblastoma who presented with leukokoria. The mean LDH level for the 14 retinoblastoma patients was significantly greater than the mean for 6 patients with leukokoria but without retinoblastoma (p less than 0.05) and the mean for 10 patients (controls) with senile cataract (p less than 0.01). Cellulose acetate membrane electrophoresis was performed on the aqueous humour of six of the patients with retinoblastoma, four of the patients with other causes of leukokoria and eight of the control patients. It showed that the protein in the aqueous humour was predominantly albumin in the patients with retinoblastoma; the globulin in these cases was usually beta-globulin. The protein was mostly or completely albumin in the three patients with Coats' disease, and the protein pattern simulated that in normal serum (owing to hemorrhage) in the patient with retinal detachment. No protein was detectable in the aqueous humour of the control patients. Thus, determining either the LDH level or the protein pattern in the aqueous humour can serve as a useful adjunct to the clinical diagnosis of retinoblastoma.