Graves’ ophthalmopathy and dermopathy

Abstract

The many and often disfiguring features of a typical patient with Graves’ ophthalmopathy are obvious at first glance (Fig. 3.3.10.1). The changed appearance of the patient has a profound effect on their emotional and social status. The various signs and symptoms can be described according to the NO SPECS classification (1) (Box 3.3.10.1). Class 1 signs can be present in any patient with thyrotoxicosis regardless of its cause. Upper eyelid retraction causes stare and lid lag on downward gaze (the latter is the well-known von Graefe’s sign). Soft tissue involvement (class 2) comprises swelling and redness of eyelids, conjunctiva, and caruncle. Symptoms are a gritty sandy sensation in the eyes, retrobulbar pressure, lacrimation, photophobia, and blurring of vision. Proptosis (class 3) can be quite marked. Upper eyelid retraction by itself may already give the impression of exophthalmos. Extraocular muscle involvement (class 4) may result in aberrant position of the globe, or fixation of the globe in extreme cases. More common is limitation of eye muscle movements in certain directions of gaze, especially in upward gaze; it is usually associated with diplopia. Diplopia will not occur if the vision of one eye is very low (e.g. in amblyopia), or if the impairment of eye muscle motility is strictly symmetrical. Patients may correct for double vision by tilting the head, usually backwards and sideways; the ocular torticollis often leads to neck pain and headache. Corneal involvement (class 5) occurs through overexposure of the cornea due to lid lag, lid retraction, and exophthalmos, easily leading to dry eyes and keratitis. Lagophthalmos is often noted first by the patient’s partner because of incomplete closure of the eyelids during sleep. Sight loss (class 6) due to optic nerve involvement is the most serious feature, often referred to as dysthyroid optic neuropathy (DON). Besides the decrease of visual acuity, there may be loss of colour vision and visual field defects. Visual blurring may disappear after blinking (caused by alteration of the tear film on the surface of the cornea due to lacrimation or dry eyes) or after closing one eye (attributable to eye muscle imbalance). Visual blurring that persists is of great concern as it may indicate optic neuropathy (2).