Case Report

Optical coherence tomography demonstrating macular retinal nerve fiber thinning in advanced optic disc drusen Ali Hassan, Pieter Gouws Department of Ophthalmology, Conquest Hospital, Hastings, East Sussex, TN37 7RD, United Kingdom

Optic disc drusen (ODD) are extracellular proteinaceous excrescences in the optic nerve head. They enlarge over time and can cause damage to nerve fibers with resulting loss of visual field. The authors report a case of advanced ODD in which macular optical coherence tomography demonstrated retinal nerve fiber thinning. A single case report of a 42-year-old woman with known ODD presented to the eye clinic with worsening field of vision which was impacting on her daily life. The patient was subject to full ophthalmic examination as well as Goldmann visual field testing, optic disc

Introduction

photography and optical coherence tomography (OCT) of both her optic discs and maculae. ODD although rare, can be visually devastating. No treatment is currently available however patients should be counseled about progressive nature of ODD and the potential for visual loss. OCT imaging of the maculae as well as optic discs may serve a role in monitoring the damage disc drusen cause to the eye. Keywords: Disc, drusen, macular, optical coherence tomography, retinal, thinning

was no longer confident driving. There was no notable medical history.

Optic disc drusen (ODD) are recognized to cause visual field defects. Enlarging drusen within the tight space of the lamina cribosa can impart compressive force on the retinal nerve fibers exiting the eye here. We present a case of bilateral advanced ODD causing visual field constriction in which optical coherence tomography (OCT) demonstrated both peripapillary and macular retinal nerve fiber layer (RNFL) thinning.

Case Report A 42-year-old Caucasian female with bilateral ODD was referred by her optician with worsening visual field loss particularly affecting her right eye. She had previously been functioning normally, however the recent visual field deterioration meant she Access this article online Quick Response Code: Website: www.ojoonline.org

Best corrected distance visual acuity (Snellen) was 6/6 -3 OD and 6/5 + 2 OS, near acuity was N5 bilaterally. A mild right relative afferent pupillary defect was noted. Examination of both anterior segments was unremarkable and Goldmann applanation tonometry revealed pressures of 12 mmHg in each eye. Fundal examination revealed healthy appearing maculae and retinae; however, each optic disc had a large number of visible confluent drusen occupying the entirety of the nerve head [Figure 1]. Goldmann visual field tests demonstrated gross constriction particularly affecting the right eye [Figure 2]. Optical coherence tomography (OCT, Cirrus HD-OCT Model 400, Carl Zeiss Meditec, US) of the optic discs and maculae were performed; these demonstrated both peripapillary and macular RNFL thinning bilaterally [Figures 3 and 4].

Discussion DOI: 10.4103/0974-620X.137167

ODD are pre-laminar excrescences of extracellular proteinaceous material anterior to the lamina cribrosa in the

Copyright: © 2014 Hassan A and Gouws P. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Correspondence: Dr. Ali Hassan, Department of Ophthalmology, Conquest Hospital, Hastings, East Sussex, TN37 7RD. E-mail: [email protected]

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Hassan and Gouws: Macular RNFL thinning in ODD

Figure 2: Goldmann visual field plots showing bilateral advanced constriction

Figure 1: (Top) Right and left optic disc color photographs showing multiple excrescences of drusen covering the entire optic nerve head. (Bottom) Fluoroscopy showing autofluorescence of the right and left optic disc drusen

Figure 3: OCT of both optic nerves showing elevated optic nerve heads and peripapillary RNFL thinning

optic nerve head.[1] Drusen can enlarge and calcify over time compressing the optic nerve and damaging the nerve fibers.[2] Peripapillary retinal nerve fiber loss has been demonstrated in patients with ODD using a number of imaging modalities including fundal photography,[3] scanning laser polarimetry[4] and optical coherence tomography.[5] The damage caused to the peripapillary RNFL has been linked to the loss of visual field in ODD.[5-7] ODD have been linked to cases of hemorrhagic and serous retinopathy, which can involve the macula;[8] however, the authors could not find any publication describing the pathological effects of ODD on the macular RNFL. In our case, the OCT demonstrated bilateral thinning of the macular nerve fiber layer in each eye; in particular, gross attenuation of the maculopapular bundle is noted. We note that the fovea, which is free of a retinal nerve fiber layer, was of normal thickness on the macular OCT for each eye. This case demonstrates the use of OCT for observing the effects of advanced ODD on the RNFL both around the optic disc and at the macula. This case also reminds us of the severity of some

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Figure 4: OCT showing thinning of the neuroretinal layers at each macula; the maculopapular bundle is particularly attenuated. Note the central foveal thickness is normal

cases of ODD and the potential for the condition to cause serious sight impairment.

References 1. 2. 3.

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Tso MO. Pathology and pathogenesis of drusen of the optic nerve head. Ophthalmology 1981;88:1066-80. Friedman AH, Gartner S, Modi SS. Drusen of the optic disc. A retrospective study in cadaver eyes. Br J Ophthalmol 1975;59:413-21. Mustonen E, Nieminen H. Optic disc drusen-a photographic study. II. Retinal nerve fibre layer photography. Acta Ophthalmol (Copenh) 1982;60:859-72. Tatlipinar S, Kadayifçilar S, Bozkurt B, Gedik S, Karaagaoglu E, Orhan M, et al. Polarimetric nerve fiber analysis in patients with visible optic nerve head drusen. J Neuroophthalmol 2001;21:245-9. Roh S1, Noecker RJ, Schuman JS, Hedges TR 3rd, Weiter JJ, Mattox C. Effect of optic nerve head drusen on nerve fiber layer thickness. Ophthalmology 1998;105:878-85. Wilkins JM1, Pomeranz HD. Visual manifestations of visible and buried optic disc drusen. J Neuroophthalmol 2004;24:125-9.

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Katz BJ, Pomeranz HD. Visual field defects and retinal nerve fiber layer defects in eyes with buried optic nerve drusen. Am J Ophthalmol 2006;141:248-53. Rubinstein K, Ali M. Retinal complications of optic disc drusen. Br J Ophthalmol 1982;66:83-95.

Cite this article as: Hassan A, Gouws P. Optical coherence tomography demonstrating macular retinal nerve fiber thinning in advanced optic disc drusen. Oman J Ophthalmol 2014;7:84-6 Source of Support: Nil, Conflict of Interest: None declared.

Oman Journal of Ophthalmology, Vol. 7, No. 2, 2014

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Optical coherence tomography demonstrating macular retinal nerve fiber thinning in advanced optic disc drusen.

Optic disc drusen (ODD) are extracellular proteinaceous excrescences in the optic nerve head. They enlarge over time and can cause damage to nerve fib...
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