The eye as a window to rare endocrine disorders.

The human eye, as an organ, can offer critical clues to the diagnosis of various systemic illnesses. Ocular changes are common in various endocrine disorders such as diabetes mellitus and Graves' disease. However there exist a large number of lesser known endocrine disorders where ocular involvement is significant. Awareness of these associations is the first step in the diagnosis and management of these complex patients. The rare syndromes involving the pituitary hypothalamic axis with significant ocular involvement include Septo-optic dysplasia, Kallman's syndrome, and Empty Sella syndrome all affecting the optic nerve at the optic chiasa. The syndromes involving the thyroid and parathyroid glands that have ocular manifestations and are rare include Mc Cune Albright syndrome wherein optic nerve decompression may occur due to fibrous dysplasia, primary hyperparathyroidism that may present as red eye due to scleritis and Ascher syndrome wherein ptosis occurs. Allgrove's syndrome, Cushing's disease, and Addison's disease are the rare endocrine syndromes discussed involving the adrenals and eye. Ocular involvement is also seen in gonadal syndromes such as Bardet Biedl, Turner's, Rothmund's, and Klinefelter's syndrome. This review also highlights the ocular manifestation of miscellaneous syndromes such as Werner's, Cockayne's, Wolfram's, Kearns Sayre's, and Autoimmune polyendocrine syndrome. The knowledge of these relatively uncommon endocrine disorders and their ocular manifestations will help an endocrinologist reach a diagnosis and will alert an ophthalmologist to seek specialty consultation of an endocrinologist when encountered with such cases.