gms | German Medical Science

A 9-year-old boy presented without any complaints for opthalmologic routine check-up in our clinics. There was no decrease of visual acuity, headache or double vision. Clinical examination revealed unilateral exophthalmus of 4 mm (OS), which the patient´s family had not noticed before. His visual acuity was 20/30 OD and OS. Anterior segment examination and intraocular pressure were unremarkable in both eyes and there was no afferent pupillary defect. Dilated fundus examination revealed no hemorrhages, venous dilatation, optic disc swelling, or choroidal folds on both eyes. Ultrasound examination (A-scan and B-scan) showed no abnormality and visual fields were full.

The patients' medical history was negative for malignant tumors or infectious disease and he did not receive ocular or systemic medications. At the age of 8 he underwent resection and recession of the medial and lateral rectus extraocular muscles (OD) because of intermittent exotropia. Further investigations into possible causes of proptosis included magnetic resonance imaging (MRI) and high resolution computed tomography (CT). Although clinically the patient had minimal changes in facial contour, MRI scan showed diffuse malformation of the left craniofacial bones involving the left orbit. Additional CT scan revealed a well defined calcified mass involving the left frontal bone, sphenoidal wings, maxilla and orbit, extending around the optic foramen. Based on the radiologic studies diagnosis of extensive monostotic fibrous dysplasia was made, and the patient was started on a conservative therapy. He received 30 mg bisphosphonate per day orally for 3 days and this therapy was repeated after 12 weeks. In the further course, the condition of the left eye remained stable with a visual acuity of 20/25. When seen in follow-up after 4 months there was no afferent pupillary defect, disc swelling or scotoma, but there was still an exophthalmus of 4 mm.

This case shows that a high degree of suspicion for exophthalmus and facial abnormalities in children is necessary, even if a patient only presents for routine check-up. Patients with fibrous dysplasia involving the deeper aspects of the face and skull base may have minimal external signs of the disease and presumably come to medical attention much later in the disease process. Therefore, the ophthalmologist plays a critical role in the early diagnosis of fibrous dysplasia.