Effect on exophthalmos of various methods of treatment of Graves' disease
G. Gwinup, A. N. Elias and M. S. Ascher
Patients with both exophthalmos and hyperthyroidism were treated with
different modes of therapy for their hyperthyroidism. Propylthiouracil
followed by surgery, propylthiouracil followed by radioactive iodine,
propylthiouracil alone, and radioactive iodine alone were used. Some of the
patients became hypothyroid and were made euthyroid with levothyroxine
sodium. Based on the mode of therapy and whether or not hypothyroidism
occurred, each patient was assigned to one of seven groups and followed up
for 18 months or longer. Careful exophthalmometry was performed at six-week
intervals in all patients. Though progression of exophthalmos was noted in
all groups, the group that received propylthiouracil demonstrated the
greatest progression of exophthalmos. In the group receiving sodium iodide
l 131 therapy and in the group treated surgically, the rate of progression
of exophthalmos was lessened with the development of hypothyroidism. Since
these hypothyroid patients were made euthyroid with supplemental
levothyroxine, it appeared that loss of thyroid tissue, rather than the
hypothyroidism per se, was responsible for the decrease in progression of
the exophthalmos. The continued progression of exophthalmos in the
propylthiouracil-treated group may be related to effects of
propylthiouracil on the immune system.
