Progressive Visual Failure in an Eye with Optic Disc Drusen and an Orbital Mass

PHOTO ESSAY

Nancy M. Younan MB, BS, MPH, and Ian C. Francis, FASOPRS

FIG. 1. Axial computed tomography demonstrating high attenuation in the right optic nerve head consistent with drusen, and a lobular mixed attenuation mass in the right orbital apex consistent with dermoid.

Abstract: A 44-year-old woman with progressive monoc 44-year-old woman with long-standing subnormal vi ular visual loss was found to have ipsilateral optic disc A sual acuity in the OD attributed to amblyopia presented drusen and an ipsilateral orbital apex mass compressing the with a 1-month history of further decline in OD vision. The optic nerve. The mass, not the drusen, was considered re patient stated that visual acuity in that eye had been mea sponsible for the worsening vision. Visual loss should not sured at 20/120 3 years earlier. There was no other signifi be glibly attributed to drusen, particularly if the visual loss cant medical history. Examination revealed visual acuities is rapidly progressive. Retrobulbar imaging should be con of count fingers OD and 20/15 OS. There was a marked sidered in such cases. right relative afferent pupillary defect. Funduscopy of the OD demonstrated optic nerve pallor with gross optic nerve (JNeuro-Ophthalmol 2003;23: 31-33) drusen and a thin nerve fiber layer. In the OS, funduscopy revealed a normal left optic nerve head. Ocular rotations and alignment were normal and there was no proptosis. Au The Ocular Plastics Unit, The Prince of Wales Hospital, Randwick, tomated static perimetry demonstrated patchy right central Sydney, Australia, and the University of NSW, Sydney, Australia. field loss OD and a normal field OS. Address correspondence to Ian C. Francis, FASOPRS, Suite 12, Chats- wood Grove, 12-14 Malvern Avenue, Chatswood 2067, NSW, Australia; Because of her history of progressive visual loss, the E-mail: [email protected] patient underwent a computed tomography (CT) of the head Copyright © Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited. J Neuro-Ophthalmol, Vol. 23, No. 1, 2003 31 JNeuro-Ophthalmol, Vol. 23, No. 1, 2003 PHOTO ESSAY

FIG. 2. Proton density axial magnetic resonance imaging FIG. 4 Coronal T1 magnetic resonance imaging shows shows the sphenoid sinus component of the mass. contour deformity of the displaced optic nerve (arrow).

and orbits. This demonstrated calcification consistent with of cases (1). They represent one of the causes of pseudo- the optic nerve head drusen, as well as a 1.6 x 0.9 cm fat papilledema (2). A proposed process of formation of drusen density bilobulated extraconal mass displacing right lateral is abnormal axonal metabolism leading to extrusion of in rectus medially (Fig. 1). The mass was located near the apex tracellular mitochondria. Calcium is then heavily deposited of the right orbit, but there was no intracranial extension. in extracellular mitochondria (3). The provisional diagnosis of right orbital apex dermoid was Most patients with optic nerve drusen are asymptom made. Magnetic resonance imaging (MRI) was then per atic. However, optic nerve drusen may lead to visual field formed to evaluate intracranial spread, which disclosed that deficits including enlargement of the blind spot and arcuate the mass extended through a small bony defect to commu scotomas (4,5). Nevertheless, loss of central visual acuity is nicate with the sphenoid sinus (Figs. 2-4). The decision was rare (1,6). When visual acuity decreases relatively suddenly, made to observe, rather than biopsy, the mass. as in our patient, a second pathology should be suspected. Optic nerve head drusen occur in an incidence of 0.4 There have been few publications describing the in to 2% of the general population and are bilateral in two-thirds frequent simultaneous occurrence of optic disc drusen

FIG. 3. Axial T1 enhanced (left) and (right) axial T2 magnetic resonance imaging show displacement and compression of the right optic nerve by the mass. Copyright © Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited. 32 © 2003 Lippincott Williams & Wilkins PHOTO ESSAY JNeuro-Ophthalmol, Vol. 23, No. 1, 2003

and orbital and intracranial tumors (2,7,8), and only one 2. Lowder C, Tomsak R, Zakov N, et al. Visual loss from pituitary tumor masked by optic nerve drusen. Neurosurgery 1981;8:473-6. case of an orbital apex dermoid, which did not extend in- 3. Tso M. Pathology and pathogenesis of drusen of the optic nerve- tracranially (9). head. Ophthalmology 1981 ;88:1066-79. 4. Brodrick JD. Drusen of the disc and retinal haemorrhages. Br Acknowledgment J Ophthalmol 1973;57:299-306. The authors thank Michael Biggs, FRACS, Consul 5. Cohen DN. Drusen of the optic disc and the development of field defects. Arch Ophthalmol 1971;85:224-6. tant Neurosurgeon of The Royal North Shore Hospital, 6. Beck RW, Corbett JJ, Thompson HS, et al. Decreased visual acuity Sydney, Australia, for his clinical expertise. from optic disc drusen. Arch Ophthalmol 1985;103:1155-9. 7. Rucker CW, Kearns TP. Mistaken diagnoses in some cases of me ningioma. Am J Opthalmol 1961;51:15-9. REFERENCES 8. Stiefel JW, Smith JL. Hyaline bodies (drusen) of the optic nerve and 1. Walsh FB, Hoyt WF. Clinical Neuro-Ophthalmology, vol 1, edn 5. intracranial tumor. Arch Ophthalmol 1961;65:814-6. In Miller N, Newman N, eds. Baltimore: Williams & 9. Pollard Z, Calhoun J. Deep orbital dermoid with draining sinus. Am Wilkins, 1998:803. J Ophthalmol 1975;79:310-3.