Ophthalmological study of epidemic dropsy.

Although epidemic dropsy was recognised in 1877 when it appeared as an epidemic outbreak in Calcutta, it came to the attention of ophthalmologists only in 1909, when Maynard' reported the occurrence of glaucoma in cases of the disease. Epidemic dropsy is an acute toxic disease characterised initially by gastrointestinal disturbances, lowgrade fever followed by oedema of the extremities, especially of the lower limbs (Fig. 1), with redness of skin, pain, and burning sensation over the oedematous part, symptoms of cardiac decompensation and breathlessness, and glaucomatous changes in the eyes. In some cases renal failure and cardiac failure may lead to death. It is well established that contamination of cooking oil with seeds of Argemone mexicana is the cause of this toxic state. The seeds contain sanguinarine hydrochloride, an alkaloid of the benzphenathrine subgroup of the isoquinoline group.2 The mode of action of sanguinarine is not clearly understood. It appears to depress the action of sympathetic stimulation and of adrenaline. It also decreases to some extent the action of acetylcholine. In epidemic dropsy it is thought to block the sulphydryl radical of the main enzyme (co-ASH) responsible for pyruvate oxidation, thereby increasing the amount of pyruvate in blood. Pathologically sanguinarine hydrochloride gives rise to dilatation and engorgement of capillaries in various tissues of the body. Gross capillary dilatation is seen in the uveal tract, particularly in the ciliary body.