|Year : 2020 | Volume
| Issue : 12 | Page : 1690-1694
Etiology of Optic Disc Swelling in a Tertiary Care Center in Nigeria
VB Osaguona, DH Kayoma
Department of Ophthalmology, University of Benin, Benin City, Edo State, Nigeria
|Date of Submission||05-Jun-2020|
|Date of Acceptance||04-Aug-2020|
|Date of Web Publication||23-Dec-2020|
Dr. V B Osaguona
Department of Ophthalmology, University of Benin, Benin City, Edo State
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Background: Optic disc swelling in clinical practice is worrisome. It may be associated with benign, sight- or life-threatening conditions. The common etiologies of optic disc swelling are variable in different communities. Aims: To determine the etiology of optic disc swelling at the Eye Clinic of the University of Benin Teaching Hospital, Nigeria. Method: The case files of all patients with optic disc swelling seen over a 7-year period were retrieved. Demographics and clinical information were obtained from their case files. The data was analyzed with the IBM SPSS Statistics Version 21 software. Descriptive analyses such as frequency, mean, and standard deviation were utilized. Results: There were 66 patients with bilateral or unilateral disc swelling. These included 23 males with a male: female ratio of 1:1.87. The age range was from 3 years to73 years; mean age 36.9 years (SD15.3). A total of 109 eyes were affected with bilateral involvement in 43 patients. Papillitis 15 (22.7%), brain tumor 8 (12.1%), and tilted disc 6 (9.1%) were the most frequent diagnosis. Papilledema in 20 (30.3%) patients, optic neuritis 19 (28.8%), and pseudopapilledema 11 (16.7%) were the most frequent etiologic processes of optic disc swelling. Conclusions: Papillitis, brain tumors, and tilted disc were the most frequent etiologies of optic disc swelling in this study. These etiologies should be excluded in patients with optic disc swelling in our clinics.
Keywords: Optic disc swelling, optic neuritis, Nigeria, papilledema, pseudopapilledema
|How to cite this article:|
Osaguona V B, Kayoma D H. Etiology of Optic Disc Swelling in a Tertiary Care Center in Nigeria. Niger J Clin Pract 2020;23:1690-4
| Introduction|| |
Optic disc swelling may be associated with benign to life-threatening conditions such as intracranial, orbital or ocular disease. Although the term papilledema means disc swelling, it is reserved for optic disc edema due to elevated intracranial pressure.,,,,, The general term disc swelling is used for any cause of optic disc swelling.,, Congenital anomalies of the optic nerve may cause elevation of the optic disc without true edema; this false impression of disc edema is referred to as pseudopapilledema and it is considered in the differential diagnosis of disc swelling.,,, Optic disc swelling from elevated intracranial pressure was the most common etiologic process of disc swelling in Nepal and Japan, while anterior ischemic optic neuropathy was the most common etiology in Koreans., Reports on common etiologies of disc swelling in Nigerians are scarce. Recognizing prevalent etiologies of disc swelling is important for health planning/intervention. This study aims to determine the etiology of disc swelling at the eye clinic of the University of Benin Teaching Hospital, Nigeria.
| Methods|| |
This study is a retrospective study conducted at the Ophthalmology Department of the University of Benin Teaching Hospital, Nigeria. The Hospital offers specialized medical services to residents within and outside the State. Ethical approval was obtained from the Ethics and Research Committee of the Hospital. The Ophthalmic Outpatient Medical Record was searched to identify all new patients presenting with optic disc swelling from January 2012 to June 2019 and their case notes were retrieved. All cases, including children and adults with disc swelling (whether unilateral or bilateral) were included in the study. Data on age, gender, laterality of optic neuropathy, visual function, and etiology of optic disc swelling was obtained. The etiologies were further classified into different etiologic subgroups: optic disc swelling from elevated intracranial pressure (papilledema), inflammation (optic neuritis), vascular, ocular, orbital disease, and congenital anomalous disc elevation (pseudopapilledema). Thorough history and examination were done for the patients. Examination included visual acuity, color vision, ocular motility, globe, eyelids, anterior segment, pupils, fundus, neurologic examination, visual field test, and blood pressure. Laboratory investigations included fasting blood sugar, full blood count, electrolytes, urea and creatinine, erythrocyte sedimentation rate, C-reative protein, and syphilis serology where necessary. Oculo-orbital ultrasound scan, magnetic resonance imaging of the orbits and brain with contrast, magnetic resonance venography, magnetic resonance angiography, or computed tomography were done where needed.
Optic neuritis was diagnosed clinically based on acute loss of vision (which may be associated with ocular pain), and additional features of optic nerve dysfunction such as relative afferent pupillary defect in unilateral cases, color vision defect, and visual field defect after excluding other possible diseases., A diagnosis of papilledema was based on the presence of elevated intracranial pressure which was confirmed on neuroimaging by the presence of an intracranial space occupying lesion or hydrocephalus, or by a normal neuroimaging and subsequent lumbar puncture with an elevated opening pressure. Pseudopapilledema was established based on the presence of an elevated disc with absent cup usually with anomalous branching of retinal vessels, and the area of disc elevation which did not extend beyond the disc margin. Also, there should be no disc hyperemia, no disc vessel dilatation, no obscuration of the blood vessels at the disc margin nor flame-shaped hemorrhages. Equivocal cases were investigated further to rule out papilledema.
Malignant hypertension was diagnosed in the presence of elevated blood pressure, disc edema, flame-shaped hemorrhages, hard exudates and cotton wool spots on the retina, andh emorrhages, hard exudates and cotton wool spots on the retina haven excluded papilledema or other diagnosis. Diabetic papillopathy was diagnosed based on optic disc edema in a patient with diabetes mellitus after excluding papilledema and other possible diseases. The diagnosis of central retinal vein occlusion was made based on the presence of dilated and tortous branches of the central retinal vein, dot, blot, and flame shaped hemorrhages in the four quadrants of the retina, cotton wool spots, and disc edema, after excluding papilledema and other possible diseases. Uveitis was diagnosed based on ocular features of uveitis such as ciliary injection, keratic precipitates, aqueous cells, and flare and disc edema, with the exclusion of other etiology of disc swelling. Other diseases were established based on typical clinical features and findings.
The data was analyzed with the IBM SPSS Statistics Version 21 software (Released 2012, IBM SPSS Statistics for Windows, Version 21.0; IBM Corp., Armonk, New York, USA). Descriptive analyses such as frequency, mean, and standard deviation were utilized. Chi-square was used to test for association among categorical variables. A P value of <0.05 was taken to be statistically significant.
| Results|| |
There were 66 patients with bilateral or unilateral disc swelling. These included 23 males with a male: female ratio of 1:1.87. The age range was from 3 years to 73 years; mean age 36.9 years (SD15.3). Nine (13.6%) patients were twenty years and below, 46 (69.7%) were from 21 years to 50 years, while 11 (16.7%) were above 50 years of age. There was bilateral involvement in 43 (65.2%) patients [Figure 1] and the total number of eyes affected was 109. [Table 1] shows the etiology of optic disc swelling. Papillitis 15 (22.7%), brain tumor 8 (12.1%), and tilted disc 6 (9.1%) were the most frequent diagnosis. Papilledema 20 (30.3%), optic neuritis 19 (28.8%), and pseudopapilledema 11 (16.7%) were the most frequent etiologic subgroups of optic disc swelling. Brain tumors were the most frequent cause of papilledema while all the cases of optic neuritis were idiopathic. There were more females in all the etiologic subgroups of disc edema, although it was not statistically significant (P = 0.846). There was also no statistically significant difference between the age groups and the etiologic subgroups (P = 0.559) [Table 2]. Visual acuity of worse than 6/60 was seen in 39 (35.7%) eyes [Figure 2]. Optic neuritis was statistically associated with poorer visual acuity (P < 0.01), while papilledema was associated with better visual acuity at presentation (P = 0.02) [Table 3].
|Figure 1: Etiology of unilateral and bilateral optic disc swelling. One patient with papilledema from a frontal lobe tumor presented with optic atrophy in the ipsilateral eye and optic disc swelling in the contralateral eye (Foster Kennedy Syndrome)|
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|Table 2: Association between age, gender and etiologic subgroup of disc swelling|
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|Table 3: Association between visual acuity and etiologic process of disc swelling|
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| Discussion|| |
Optic disc swelling is a bothersome finding in clinical practice. It may be a presentation of benign conditions as in pseudopapilledema, sight-threatening conditions as in ischemic optic neuropathy, or life-threatening conditions with elevated intracranial pressure. It affects both males and females; however, it was seen more frequently in females in our study. This is similar to the finding by Vaidya et al. in which 64% were females, but in contrast to the studies by Ijeri and Jyoti, and Shah who reported a slight male preponderance in 53.5% and 55.3%, respectively. Optic disc swelling associated with raised intracranial pressure is referred to as papilledema.,,,,, The causes of papilledema include intracranial tumors, idiopathic intracranial hypertension, cerebral hemorrhage, head trauma, meningitis, hydrocephalus, and cerebral venous sinus thrombosis., A patient with a frontal lobe tumor may present with ipsilateral optic atrophy from compression of the intracranial optic nerve by the tumor and contralateral disc edema from elevated intracranial pressure (Foster Kennedy Syndrome)., The atrophic optic nerve head cannot swell. This was the case in one of our patients with papilledema. Optic disc swelling from elevated intracranial pressure was the most prevalent etiologic process in unilateral and bilateral disc edema in 35.7% of 98 Nepalese, and in bilateral disc swelling in 59% of 121 Japanese patients. In addition, brain tumors were the most frequent cause of papilledema in these two studies., Papilledema was present in close to one-third of our patients, and brain tumor was the most frequent etiology followed by head trauma and intracranial collections. Thus, intracranial processes should be considered in patients with optic disc swelling in our clinics. A history of other clinical features of raised intracranial pressure such as headache, nausea, vomiting, diplopia, transient visual loss, pulsatile tinnitus, ataxia, and altered consciousness is helpful in making a diagnosis of papilledema.,
Optic neuritis refers to inflammation of the optic nerve which could be idiopathic, or result from demyelinating disorders such as multiple sclerosis or neuromyelitis optica, from infections, inflammatory disease, or autoimmune disorders. The patient may present with ocular pain that may worsen on eye movement, acute vision loss, and dyschromatopsia (loss of color vision). In our study, optic neuritis was the second most common etiologic process of disc swelling, and papillitis was the more frequent type. However, optic neurits was the most frequent in 46.5% of 43 patients in India and 36.8% of 38 patients in Nepal. An association between optic neuritis and multiple sclerosis in Caucasians is well documented.,,, In our study, all the cases of optic neuritis were idiopathic; no case was associated with multiple sclerosis. Even so, multiple sclerosis is reported to be rare in Nigerians.
Anterior ischemic optic neuropathy was the most common cause of optic disc swelling in 22.3% of 93 patients in Korea; and specifically, nonarteritic anterior ischemic optic neuropathy was the most common etiology reported in 37.4% of 49 patients by Jung et al. A significant number of their study population were older patients., In the United States of America, nonarteritic anterior ischemic optic neuropathy is documented to be the foremost cause of acute optic neuropathy in those older than 50 years. In contrast, vascular causes (from nonarteritic anterior ischemic optic neuropathy, hypertension, and diabetes mellitus) accounted only for a few of the disc swelling in our study. This may not be surprising as only a small proportion of the patients were above the age of 50 years—the age at which persons are more prone to having vasculopathic risk factors such as hypertension, diabetes mellitus, and dyslipidaemia. Ocular diseases such as uveitis,,, central retinal vein occlusion,,, and ocular hypotony, may also cause optic disc edema. In the current study, central retinal vein occlusion and uveitis were the identified ocular causes of disc swelling.
Pseudopapilledema was notable in this study as it was in other studies.,, Pseudopapilledema is a false impression of disc edema due to various congenital anomalies of the optic disc such as optic disc drusen, myelinated retinal nerve fibers, and small choked disc in hypermetropia., Tilted disc, crowded disc, and myelinated retinal nerve fibers were the congenital anomalies of the disc identified in this study, while Vaidya et al. noted tilted disc, optic disc drusen, and crowed disc in their work. The presenting visual acuity in the eyes with disc swelling was variable; however, patients with optic neuritis presented mostly with visual acuity worse than 6/60 while those with papilledema presented largely with visual acuity of 6/18 or better which was statistically significant. This is in keeping with the finding that visual acuity is usually unaffected in papilledema until the late stages,,, unlike in optic neuritis where vision loss is an early presentation with visual acuity worse than 6/60 in as much as 35.9%–93% of cases.,,,
Since the causes of optic disc swelling are variable, differ in management, and may be benign, sight- or life-threatening, a detailed history and examination, is necessary and helpful in the differential diagnosis. Our study has some limitations; it was carried out at the eye clinic and thus may not be a true representation of the etiology of optic disc swelling in the whole hospital or in the community. It, however, shows optic disc swelling from elevated intracranial pressure, inflammation, and congenital disc anomalies to be significant etiologic processes in the eye clinic. In conclusion, papillitis, brain tumor, and tilted disc were the most frequent etiologies of optic disc swelling in our study. These etiologies should be excluded in patients with optic disc swelling in our eye clinics.
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Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2]
[Table 1], [Table 2], [Table 3]