TNOA Journal of Ophthalmic Science and Research

CASE REPORT
Year
: 2018  |  Volume : 56  |  Issue : 4  |  Page : 257--260

Misdiagnosis of missed diagnosis


Sadiqha S Banu, Malarchelvi Palani, Pratheeba Devi Nivean, M Nivean 
 Department of Opthalmology, M. N. Eye Hospital, Chennai, Tamil Nadu, India

Correspondence Address:
Dr. M Nivean
M. N. Eye Hospital, Chennai, Tamil Nadu
India

Abstract

Papilledema is swelling of the optic nerve head, a sign of increased intracranial pressure. It can have underlying life-threatening etiologies such as intracranial space-occupying lesions or meningitis. However, pseudopapilledema is elevation of the optic disc secondary to local underlying structural conditions. Distinguishing between papilledema and pseudopapilledema is needed to avoid subjecting the patient to unnecessary tests and anxiety associated with it. We report a case of an 18-year-old male who presented to us with the clinical suspicion of disc edema. Simple noninvasive investigations such as red-free fundus photography and ultrasound B-scan aided us to diagnose it as a case of pseudopapilledema-optic nerve head drusen. Thus, a high index of suspicion along with the ancillary tests is helpful in differentiating pseudopapilledema from true papilledema.



How to cite this article:
Banu SS, Palani M, Nivean PD, Nivean M. Misdiagnosis of missed diagnosis.TNOA J Ophthalmic Sci Res 2018;56:257-260


How to cite this URL:
Banu SS, Palani M, Nivean PD, Nivean M. Misdiagnosis of missed diagnosis. TNOA J Ophthalmic Sci Res [serial online] 2018 [cited 2019 Nov 12 ];56:257-260
Available from: http://www.tnoajosr.com/text.asp?2018/56/4/257/252501


Full Text



 Introduction



Pseudopapilledema is a benign elevation of the optic nerve head and is usually caused by hyperopia, hyaloid remnants (retained or “hyperplastic” glial tissue), myelinated nerve fibers, hyaline bodies (drusen), congenital elevations without visible hyaline bodies.[1]

Optic disc drusens (ODD) are depositions of mucopolysaccharides and proteinaceous material that accumulate anterior to the lamina cribosa within the optic nerve head.[2]

 Case Report



An 18-year-old male was diagnosed and treated for papilledema by a neurologist. He came to our clinic for a second opinion. The patient had a history of headaches on and off for the past 3 months; there was no associated nausea, vomiting, loss of consciousness, transient visual obscuration, or diplopia. There was no associated systemic disease. Neurological examination of the patient was normal. Slit lamp examination of the anterior segment was normal, his pupils were briskly reactive, and there was no relative afferent pupillary defect. Fundus examination [Figure 1] revealed moderate disc elevation along with blurring of disc margins, cup-disc ratio was obliterated elevation was confined only to optic disc, and peripapillary nerve fiber was distinct. No venous congestion, no exudates, and no spontaneous venous pulsations were noted. His unaided visual acuity for distance was 6/24 with a myopic correction of −4 D; his best-corrected visual acuity was 6/6 in both eyes. Intraocular pressures were 16 and 13 mmHg, respectively, in the right and left eye measured using noncontact tonometer. Color vision in both eyes was normal on testing with Ishihara's chart. Visual fields [Figure 2] and [Figure 3] analysis was done with Humphrey's field static perimetry, fields were reliable and normal, and there was no enlargement of the blind spot. Red-free fundus photography demonstrated autofluorescence of the optic nerve head. Ultrasound B-scan [Figure 4] done revealed highly reflective round structures with acoustic shadowing in the medium gain scan suggestive of ODD. Spectral domain optical coherence tomography (SD-OCT) [Figure 5] (Optovue-iVue) of both eyes revealed hyperreflective mass causing focal, irregular elevation of optic nerve head and adjacent retina and there was no associated retinal nerve fiber loss in any of the quadrants; hence, the diagnosis of pseudopapilledema was made. The patient was referred to a neurologist, and neuroimaging was done. Magnetic resonance imaging (MRI) brain revealed no significant abnormality, and MRI orbit showed prominent cerebrospinal fluid spaces around bilateral orbit nerves. Retrobulbar portion of bilateral orbit nerve appears normal in signal, and no significant abnormality was seen on MRI venogram. On review, the patient was stable with best-corrected visual acuity of 6/6 and no associated ocular or systemic complaints. His pupil was briskly reactive. Anterior-segment and fundus examination revealed no additional changes.{Figure 1}{Figure 2}{Figure 3}{Figure 4}{Figure 5}

 Discussion



Papilledema is acquired bilateral optic disc swelling attributed to increased intracranial pressure, whereas pseudopapilledema is the appearance and false impression of bilateral disc swelling that is associated with an underlying anomalous benign conditions. Many patients with pseudopapilledema are referred for neuro-ophthalmologic evaluation only after being subjected to neuroimaging, lumbar puncture, and extensive laboratory studies. The diagnostic uncertainty and the false alarm created by this finding conceal the fact that the patient has no other signs or symptoms of increased intracranial pressure. A thorough history and a dilated fundus examination will often facilitate the diagnosis. ODD should be considered in all patients with blurred or elevated discs before being treated for papilledema. The word “drusen” originally meant tumor, swelling, or tumescence. Drusen of the optic disc was first described by Liebreich in 1868. Other terms for these lesions include hyaline bodies and colloid bodies of the optic disc. ODD is found in approximately 0.3%–2% of the general population with bilateral distribution in 66%–85%.[3] Pathogenesis of the ODD is unknown, but there are three classic theories; the first suggests abnormal axonal metabolism leads to their formation. The second attributes ODD to congenitally dysplastic disc.[4] According to the last theory, ODD has smaller than normal scleral canal which compresses optic nerve, blocking axoplasmic flow, leading to ganglionic cell axonal damage and death.[5] As axons die extrude their mitochondria which serve as a nidus for calcification. Good clinical history and detailed clinical examination will help in differentiating between these two entities. Neurological symptoms such as nausea, vomiting, headache with postural variation, transient obscuration of vision, and tinnitus will be more evident in true papilledema.[6] On fundoscopy, optic disc will be elevated, hyperemic, peripapillary vessel obscuration, flame-shaped hemorrhages, cotton wool spots, with or without Paton's lines, microvascular dilatation, and no spontaneous venous pulsations will be seen in true papilledema, whereas in pseudopapilledema, elevation will be confined to the optic disc with obliterated cup-disc ratio with anomalous branching pattern.

Other ancillary tests such as fundus photography in red-free light, ultrasonography B scan, computed tomography scan, fluorescein angiography, and OCT can aid in the detection of disc drusen. In our patient, in ultrasonography B-scan of the posterior segment, we could see echodense structure with acoustic shadowing at the level of optic nerve head of both eyes, suggestive of calcified disc drusen. SD-OCT image of our patient demonstrated the irregular contour of the optic nerve head with maximum thickness and displacement of the nerve fiber layer with underlying lucency of retinal pigment epithelium. A study by Auw-Haedrich in 2002 revealed that Goldmann visual fields may show areas of nerve fiber defects (most commonly inferior nasal area) and enlargement of the blind spot with or without constriction of the peripheral fields. In optic nerve head drusen, ODD becomes symptomatic due to either insidious field loss or spontaneous hemorrhage, at times associated with choroidal neovascular membrane formation; hence, periodic follow-up is necessary. Patients with documented optic nerve drusen should be followed with serial visual field examinations, optic nerve fiber analysis.

 Conclusion



ODD should always be considered as a primary diagnostic evaluation in cases presenting with disc edema. Detailed history and comprehensive ophthalmic and systemic examination are mandatory along with noninvasive investigations such as red-free fundus photography, ultrasound B scan, and SD-OCT for the accurate diagnosis which will prevent the patient being subjected to invasive procedures.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

1Savino PJ, Glaser JS. Pseudopapilledema versus papilledema. Int Ophthalmol Clin 1977;17:115-37.
2Tso MO. Pathology and pathogenesis of drusen of the optic nerve head. Ophthalmology 1981;88:1066-80.
3Lorentzen SE. Drusen of the optic disk. A clinical and genetic study. Acta Ophthalmol (Copenh) 1966:Suppl 90:1-180. Epub 1966/01/01.
4Antcliff RJ, Spalton DJ. Are optic disc drusen inherited? Ophthalmology 1999;106:1278-81.
5Mullie MA, Sanders MD. Scleral canal size and optic nerve head drusen. Am J Ophthalmol 1985;99:356-9.
6Mustonen E, Kallanranta T, Toivakka E. Neurological findings in patients with pseudopapilloedema with and without verified optic disc drusen. Acta Neurol Scand 1983;68:218-30.