Pituitary Exophthalmos : An Assessment of Methods of Treatment

EXOPHTHALMIC ophthalmoplegia, progressive or malignant exophthalmos, and thyrotropic exophthalmos are synonyms for the same clinical conditions.The various terms imply that this bilateral exophthalmos is associated with ophthalmoplegia, that the condition is progressive, leading, if untreated, to grave damage and eventual loss of the eyes, and that it is believed to be due to excess of pituitary thyrotropic hormone.Sound experimental evidence, such as to make this belief acceptable, has accumulated.Among others, Collip and Anderson (1935), Paulson (1939), Aird (1941), and Dobyns (1946), have been able to produce bilateral exophthalmos experimentally in the guinea-pig by administration of pituitary thyrotropic hormone.The exophthalmos so produced is characterized by its persistence during anaesthesia and after death.It is associated with myopathy of the extra-ocular muscles.It appears more rapidly and is of greater severity in the thyroidectomized animal.It is progressive even after administration of thyrotropic hormone has ceased.In the first three of these characteristics it resembles the spontaneous disease observed in human beings.The clinical features and the pathology of the condition have been fully described by Brain (1936), Naffziger (1931, 1933, 1938, 1948), Mann (1946), and Dobyns (1950).Clinically this condition is distinct from the more common type of exophthalmos associated with Graves' disease.The first symptom is usually a burning sensation and watering of the eye, but not infrequently diplopia is experienced before the patient has become aware of protrusion of the eyeball.More often than not the condition presents as an asymmetrical one, and occasionally it is unilateral in the early stages so that distinction from orbital tumour may cause difficulty.It seems appropriate here to stress that in this variety of exophthalmos, more aptly called proptosis, there is rarely lid retraction.From the onset, the lid space is narrow, rather than enlarged, owing to swelling of the lids.There are heavy bags of oedema below the eyes and there is oedema of the conjunctiva of lids and of globe.