|Year : 2023 | Volume
| Issue : 1 | Page : 113-116
Unilateral buried optic nerve head drusen triggering central retinal vein occlusion in young – Discovering an eclipsed entity
Muthu Krishnan Vallinayagam, S Koushik, Amirtha Vaithianathan, Dipika Sainath
Department of Ophthalmology, Mahatma Gandhi Medical College and Research Institute, Sri Balaji Vidyapeeth, Puducherry, India
|Date of Submission||16-Mar-2021|
|Date of Acceptance||11-Jun-2022|
|Date of Web Publication||12-Dec-2022|
Muthu Krishnan Vallinayagam
Department of Ophthalmology, Mahatma Gandhi Medical College and Research Institute, Puducherry
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Optic nerve head (ONH) drusen are acellular calcified concretions. Buried drusen manifests as pseudopapilledema. The compressive effects of ONH drusen can rarely precipitate central retinal vein occlusion (CRVO). The superimposition of pseudopapilledema on disc edema in CRVO poses a diagnostic dilemma. A 40-year-old female without systemic comorbidities presented with resolving CRVO. An exhaustive systemic workup revealed no abnormalities. Ultrasonography demonstrated buried ONH drusen. This unusual etiology must be considered in a young patient in the absence of systemic risk factors, persistence of “nasally conspicuous” disc elevation, and presence of peripapillary hemorrhages. Ultrasonography must be incorporated in the diagnostic armamentarium in a young patient with CRVO.
Keywords: Central retinal vein occlusion, optic nerve head drusen, ultrasonography, young
|How to cite this article:|
Vallinayagam MK, Koushik S, Vaithianathan A, Sainath D. Unilateral buried optic nerve head drusen triggering central retinal vein occlusion in young – Discovering an eclipsed entity. Oman J Ophthalmol 2023;16:113-6
|How to cite this URL:|
Vallinayagam MK, Koushik S, Vaithianathan A, Sainath D. Unilateral buried optic nerve head drusen triggering central retinal vein occlusion in young – Discovering an eclipsed entity. Oman J Ophthalmol [serial online] 2023 [cited 2023 Mar 26];16:113-6. Available from: https://www.ojoonline.org/text.asp?2023/16/1/113/363276
| Introduction|| |
Optic nerve head (ONH) drusen are acellular calcified deposits which are categorized into buried and exposed forms. It occurs in 0.3%–0.5% of the population. This condition is usually bilateral (67%–91%) and exhibits a female predilection. Buried ONH drusen manifest as “pseudopapilledema.” The mechanical effects of ONH drusen can rarely result in central retinal vein occlusion (CRVO), choroidal neovascularization, subretinal hemorrhage, and anterior ischemic optic neuropathy., CRVO is uncommon in young and entails a vigilant search for unusual risk factors. CRVO in a young patient consequential to ONH drusen is discussed here.
| Case Report|| |
A 40-year-old female with no systemic comorbidities presented with sudden, painless diminution of vision in the left eye 4 months back. There was no relevant family history or past history of thrombotic episodes. Best-corrected visual acuity was 20/400 in the left eye and 20/20 in the right eye. A relative afferent pupillary defect was present and the rest of the anterior segment examination was unremarkable. The gonioscopic examination was normal with an intraocular pressure of 16 mmHg recorded bilaterally on Goldmann applanation tonometry. Fundus revealed elevated, nonhyperemic optic disc which was more conspicuous nasally. Blurred disc margins, moderate venous tortuosity, peripapillary hemorrhages, vascular sheathing, and macular edema were seen, consistent with resolving CRVO [Figure 1]. There was no evidence of vasculitis. The right eye examination was unremarkable.
|Figure 1: Color fundus photograph of the left eye shows an elevated optic disc with blurred margins, moderate venous tortuosity, vascular sheathing, peripapillary hemorrhages (white arrow), and macular edema, consistent with resolving CRVO. CRVO: Central retinal vein occlusion|
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Fundus fluorescein angiography (FFA) showed a delay in arteriovenous transit time, venous wall staining, petaloid leak at the macula, late peripapillary leak, and staining of the optic disc [Figure 2]. Spectral-domain optical coherence tomography (SD-OCT) showed atrophy of inner retinal layers and intraretinal hyporeflective cystoid spaces at the macula [Figure 3]a. Tomography of ONH demonstrated increased peripapillary retinal nerve fiber layer thickness suggesting disc edema [Figure 3]b and [Figure 3]c.
|Figure 2: Fluorescein angiography of the left eye shows venous staining, petaloid leak at the macula, late leak, and staining of the optic disc|
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|Figure 3: (a) Horizontal SD-OCT scan through macula in the left eye shows atrophy of inner retinal layers and intraretinal hyporeflective cystoid spaces, (b) vertical sectional image of the optic nerve head, and (c) analysis of circumpapillary RNFL using SD-OCT shows thickening of RNFL consistent with disc edema. SD-OCT: Spectral-domain optical coherence tomography, RNFL: Retinal nerve fiber layer|
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Blood pressure was recorded to be 130/80 mmHg. A battery of investigations for vascular risk factors including complete hemogram, erythrocyte sedimentation rate, blood glucose, cholesterol, immunoglobulin levels, C-reactive protein, protein C and S assay, antithrombin III assay, homocysteine, factor V, antinuclear antibody, anticardiolipin antibody, and antiphospholipid antibody titer were within normal limits.
The persistence of severe disc elevation after 4 months of onset, especially conspicuous on the nasal aspect of the optic disc, and the presence of peripapillary hemorrhages aroused the suspicion of an occult etiology. Ultrasound (US) B-scan of the left eye revealed a highly reflective ovoid lesion at the elevated optic disc which persisted in reducing the gain, suggesting buried ONH drusen [Figure 4]. US examination of the right eye was unremarkable.
|Figure 4: Ultrasound B-scan image of the left eye shows increased echogenicity of ONH (white arrow) consistent with buried ONH drusen. ONH: Optic nerve head|
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| Discussion|| |
ONH drusen are calcified hyaline deposits in the optic disc resulting from prelaminar deposition of calcium, glycoprotein, mucopolysaccharides, and amino acids. A small disc diameter and translaminar pressure gradient play an imperative role in pathogenesis. Autosomal dominant inheritance is reported in familial cases. Unilateral buried ONH drusen manifesting as CRVO has been reported once in the literature. Although often bilateral, the absence of ONH drusen in the contralateral eye should not prompt the dismissal of diagnosis.
The configuration of ONH drusen can be buried or exposed, both exhibiting a predilection for the nasal aspect of the optic disc. Pseudopapilledema is exemplified by the absence of disc hyperemia, telangiectasias, and exudates. The striking disc elevation more protuberant nasally offers a salient diagnostic clue. The “pseudopapilledema” can be subdued by concurrent disc edema in CRVO, posing a diagnostic ambiguity. A nonhyperemic disc and nasally conspicuous disc elevation offer corroborative evidence supporting ONH drusen.
Peripapillary hemorrhages are a chronicled feature of ONH drusen hypothesized to result from rupture of peripapillary vessels by the sharp edges of concretions., A nasal predilection of peripapillary hemorrhage against a background of resolving CRVO is speculated to be indicative of ONH drusen in this case.
Advancing age, hypertension, diabetes mellitus, and hyperlipidemia constitute the most common risk factors for CRVO. Barring hyperviscosity syndromes, thrombophilias, and vasculitis, CRVO in young may be associated with ocular risk factors including glaucoma and thyroid orbitopathy., Although not an unprecedented etiology, ONH drusen is a rare precipitating factor.,, The absence of conventional risk factors after an exhaustive systemic workup should prompt investigation along the lines of ONH drusen.
Although asymptomatic in majority, visual field defects may be encountered in ONH drusen. Elevated venous pressure as a repercussion of central retinal venous compression at the lamina cribrosa is implicated in the genesis of CRVO. The poor visual acuity, in this case, is attributed to long-standing macular edema and retinal atrophy documented on OCT.
FFA reveals late peripapillary circumferential staining in buried ONH drusen. Coexistent “true” disc edema demonstrates late leakage and staining. The significant overlap of the aforementioned features as seen in this patient makes FFA less utilitarian.
A highly echogenic focus persisting at a low gain is diagnostic of ONH drusen in US. Although unremarkable in one-third of cases of suspected ONH drusen, a hyporeflective core with a hyperreflective cap termed “cap sign” is elucidated on SD-OCT. Enhanced depth imaging OCT is an emerging modality with a higher detection rate. OCT being inconclusive, US features commensurate with ONH drusen unveiled the possible ocular risk factor for CRVO in this patient.
| Conclusion|| |
ONH drusen are an unusual etiology for CRVO. The superimposed disc edema in CRVO and overlapping clinical features may confound the diagnosis of ONH drusen. Young age, normal systemic workup, nasally predominant disc edema, and peripapillary hemorrhages vindicate the search for an unusual ocular risk factor. Ultrasonography substantiates the diagnosis of ONH drusen in a young patient with CRVO.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given her consent for her images and other clinical information to be reported in the journal. The patient understands that her name and initials will not be published and due efforts will be made to conceal her identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4]