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Three patients with restrictive ophthalmopathy due to thyroid eye disease, complained of flashing lights. They reported that the lights appeared to be directly above their heads and these symptoms were most noticeable when they closed their eyes before going to sleep at night and could be produced by attempted upgaze with closed lids in a darkened room. We thought that these flashing lights were probably phosphenes induced by pressure on the globe from the tight inferior rectus muscle or by traction at its insertion. Our aim was to determine the frequency of phosphenes in patients with thyroid eye disease and with tight inferior recti, in order to establish whether there is a relation between the symptoms and the presence of tight muscles.
Materials and methods
Thirty consecutive patients referred for consideration of extraocular muscle surgery in the dry or burnt out phase of thyroid eye disease were recruited. All patients had restrictive thyroid ophthalmopathy affecting the inferior rectus muscle. Patients were identified retrospectively from operative, outpatient, and radiological records. Controls were age and sex matched oculoplastic patients without intraocular disease.
Thyroid eye disease had been diagnosed on the basis of clinical presentation, restrictive ophthalmopathy, and radiological evidence of extraocular muscle enlargement. All patients had biochemical evidence of thyroid dysfunction in the past. In addition, the degree of inflammatory activity on short tau inversion ratio (STIR) sequence magnetic resonance imaging (MRI) 1 was documented. Ocular motility assessment included Hess charts, fields of binocular single vision and uniocular fields of fixation. 2 Intraocular pressure measurements in primary position and upgaze were noted where available. The nature of any immunosuppressive treatment and surgical intervention was documented.
Twenty patients had radiological imaging, 19 with MRI and 11 cine MRI, 3 including patients with spontaneous phosphenes and some with raised intraocular pressure on upgaze. Three scans were performed specifically to examine globe compression. Cine MRI with longer exposure was performed in an attempt to improve image resolution. All scans were examined for evidence of globe compression, particularly on upgaze.
Patients who spontaneously complained of flashes of light were questioned as to the nature of their symptoms. Other patients were directly questioned for the...