Acute keratoconus induced by hypothyroxinemia during pregnancy.

Keratoconus is a bilateral non-inflammatory corneal ectasia with an incidence of approximately 1 per 2000 in the general population. The etiology of keratoconus is multifactorial, although not completely understood. Several clinical observations suggest that thyroid gland dysfunction is associated with keratoconus pathophysiology. Pregnancy represents a major alteration in the maternal endocrinologic status characterized by modified function of the thyroid gland. We report on a 33-yr-old pregnant women suffering from keratoconus, who presented simultaneously with a remarkable deterioration of the disease during gestation and with thyroid gland dysfunction. Acute keratoconus in this patients coincided with the lowest plasma T4 level reached during pregnancy. During the third trimester of gestation, the keratoconus receded significantly. Here we provide direct evidence in support of a possible linkage between keratoconus and thyroid gland dysfunction, assumed by previous clinical observations. This case report is the first to suggest that changes in maternal thyroid hormone levels during pregnancy can aggravate the progression of keratoconus.