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ORIGINAL ARTICLE
Year : 2023 | Volume
: 37
| Issue : 1 | Page : 25-31
Visual outcomes of idiopathic intracranial hypertension in a neuro-ophthalmology clinic in Jeddah, Saudi Arabia
Rahaf Mandura1, Dareen Khawjah1, Abeer Alharbi2, Nawal Arishi3
1 Department of Ophthalmology, King Abdulaziz University, Jeddah, Saudi Arabia
2 Department of Ophthalmology, Ohud Hospital, Medina, Saudi Arabia
3 Department of Ophthalmology, Neuro-Ophthalmology Division, Jeddah Eye Hospital, Jeddah, Saudi Arabia
Correspondence Address:
Rahaf Mandura
Department of Ophthalmology, King Abdulaziz University, 80017, Jeddah 21589
Saudi Arabia
Source of Support: None, Conflict of Interest: None
DOI: 10.4103/sjopt.sjopt_173_21
PURPOSE: Idiopathic intracranial hypertension (IIH) is a disorder with elevated intracranial pressure more than 250 mm H2O, without evidence of meningeal inflammation, space-occupying lesion, or venous thrombosis. In this study, we aim to study the clinical profile, evaluation, management, and visual outcome in a hospital-based population of IIH cases in Jeddah.
METHODS: This is a retrospective observational cohort study that included the medical records of all patients referred to neuro-ophthalmology service for evaluation of papilledema. The medical records have been reviewed from October 2018 to February 2020 at Jeddah Eye Hospital, Saudi Arabia. A total of 51 patients presented with papilledema in the studied period. Forty-seven patients met our inclusion criteria and were included in the study.
RESULTS: The study found that the incidence rate of IIH is 16:100 of the referred cases to the neuro-ophthalmology clinic. Most of the patients were females (41, 91.2%), with a mean age of presentation of 32 ± 11 years. The most common presenting symptom was headache (40 patients, 88.8%), followed by transient visual obscuration (TVO) (20 patients, 44.4%), and reduced visual acuity (15 patients, 33.3%). All 45 patients were started on medical treatment with oral acetazolamide with four patients (8.8%) shifted to topiramate because of the lack of response or intolerance to acetazolamide while four patients (8.8%) underwent lumbar-peritoneal shunt because of inadequate control of the disease despite the treatment with medical therapy. For both eyes, the change in visual acuity across all assessment points was statistically significant. Nevertheless, there were no significant changes in the visual field findings among all of the compared assessment points.
CONCLUSION: The present study has shown that IIH-related papilledema is common in young female patients with headaches, TVOs, and reduced visual acuity. Those are the most common symptoms in our IIH population. Medical treatment and monitoring of IIH is efficient and should be considered to enhance the prognosis of IIH-related complications. In addition, the visual acuity and the visual field should be frequently monitored for these patients.
Keywords: Clinical profile, evaluation, headache, idiopathic intracranial hypertension, intracranial hypertension, papilledema, visual outcome
Idiopathic intracranial hypertension (IIH) is defined by the elevation of intracranial pressure (ICP) more than 250 mm H2O which is not caused by meningeal inflammation, venous thrombosisor a space-occupying lesion within the brain.[1] Dandy[2] originally described it as “pseudo-tumor cerebri” as a result of the common clinical pictures observed in IIH patients with no evidence of tumors, but with normal neuroimaging and cerebrospinal fluid (CSF) analysis.[3],[4]
The symptoms of IIH include headache, neck and back pain, pulsatile tinnitus, transient visual obscuration (TVO), and diplopia[3],[4] The development of papilledema in patients with IIH might lead to permanent visual loss, especially in cases of neglect or inadequate treatment.[5] However, the treatment might be challenging as the early diagnosis might not be possible due to the absence of a specific clinical picture for this event.[6] Therefore, the diagnosis should be established early based on the modified Dandy criteria.[2] The criteria include the presence of an increased ICP, normal CSF composition with elevated opening pressure (>200 mm of water in nonobese and >250 mm of water in obese patients), normal magnetic resonance imaging (MRI), and the presence of typical papilledema. When papilledema is absent, establishing the diagnosis might be challenging and needs specific neuroimaging criteria to establish a proper diagnosis and subsequent successful management.[7] The management of patients with IIH can be divided into medical and surgical modalities.[8],[9] In cases with mild and moderate vision loss, medical treatment is recommended and can be achieved by acetazolamide, which is a carbonic anhydrase inhibitor.[10] On the other hand, surgical intervention, which is usually performed by CSF diversion procedure or optic nerve sheath fenestration surgeries, might be applied for cases that present with severe vision loss and headache or severe gradual deterioration in vision after the failure of medical therapy.[11],[12]
The incidence of IIH in the general population is 1:100,000,[13],[14] with evidence supporting the fact that IIH usually develops in young, female, and obese patients around the childbearing age. However, it may also develop in other patients of different demographics.[1],[3],[15] Moreover, it has also been reported that patients with recent weight gain have a higher risk even if they have a normal body mass index.[3],[15],[16] Despite these reports, the pathophysiology of IIH is still poorly understood.[17] Besides, epidemiological and clinical studies about IIH patients are not frequently found. Therefore, in this study, we aim to report the demographics, clinical features, medications, and visual affection and prognosis of our IIH population in Jeddah, Saudi Arabia.
MethodsThe medical records of all patients referred to neuro-ophthalmology service for the evaluation of papilledema were retrospectively reviewed from October 2018 to February 2020 at Jeddah Eye Hospital, a referral center in Jeddah, Saudi Arabia. A total of 51 patients presented with papilledema with only 45 patients included that met our inclusion criteria of probable IIH diagnosis. The clinical confirmation of IIH was based on the Modified Dandy's diagnostic criteria[2] or the probability of having IIH. Four cases were excluded from the study as they had an underlying pathological cause for the papilledema.
Data were collected using a Google form with information about patient's demographics, the clinical course of the disease including the presenting complaint, the use of any offending medication like steroid and oral contraceptive, relevant ocular and medical history, detailed ocular and neurological exam in the first as well as in the follow-up visits. Visual acuity was assessed using Snellen visual acuity chart. Optic disc assessment was assessed by Frisen scaleusing a 90-diopter lens and slit lamp. Visual field assessed by octupus visual field test (OCTOPUS 900 SN3038). Patients were followed up for a minimal period of 6 months. All patients were started on medical therapy with acetazolamide (Diamox) and some patients were treated with topiramate. The dose of (Diamox) was tapered for patients who showed improvement. Very few exhibited progressions on medical treatment and were further treated surgically by inserting a lumboperitoneal shunt by the neurosurgery team.
Categorical variables were represented as frequencies and percentages while utilizing Chi-squared or Fisher's exact test for testing the differences among different groups. For continuous variables, the representations were represented as means and standard deviations. To assess changes from baseline findings to the next point of follow-up, Wilcoxon signed-rank test was used and to compare the whole changed among all assessment points, Friedman's test was used. Data were analyzed using IBM SPSS program version 26 (IBM Corporation, Armonk, NY, USA) and a P ≤ 0.05 was considered significant for all tests.
ResultsDemographics, incidence rate, and medication history
Two hundred and ninety-three patients were referred to neuro-ophthalmology clinic between October 2018 and February 2020. Out of the referred patients, 246 patients (83.96%) were without IIH and 45 patients (16.04%) had IIH. Fifty-one patients presented with papilledema, 45 patients were diagnosed with IIH based on clinical and radiological findings. The mean age of onset was 32 ± 11 years, and the age group 25–34 years was the most common one. Out of the included patients, 97.7% were Saudi and 91.2% were females. About 88.9% of the patients reported a history of at least one medication, 6.6% were on steroids, and 6.6% were taking oral contraceptives [Table 1].
Clinical characteristics and examination
All patients were symptomatic with headache being the most common presenting symptom, followed by TVO, reduced visual acuity, nausea, diplopia, vomiting, and tinnitus [Figure 1]. On presentation, the best-corrected visual acuity, which was assessed using Snellen visual acuity chart, was found to range from 6/6 to light perception. Meanwhile, 41 eyes had 6/6 visual acuity, 41 eyes had 6/9–6/18 visual acuity, 5 eyes had 6/24–6/60, and 3 eyes had <6/60. Color vision test using Ishihara chart has shown that color vision was normal 16/16 in 37 patients (78.7%) but was affected in 10 patients (21.3%). Moreover, an advanced constricted visual field was found in 10 patients (21.3%). A total of 37 patients were only assessed in regard to visual field as eight patients had incomplete data in the files. The most common visual field defect was inferonasal defects (10 patients, 27%). Nonspecific defects were found in nine patients (24.3%) and the inferior altitudinal defect was found in two patients (5.4%). Nevertheless, 16 patients (43.2%) had normal visual fields [Table 2]. Papilledema was found symmetrical bilaterally in 43 patients (91.4%) and asymmetrical bilateral optic disc edema was found in four patients (8.5%). The detailed findings of optic disc examination in both eyes are presented in [Table 2]. Seven patients agreed to undergo lumbar puncture and CSF analysis to confirm the diagnosis and showed normal CSF composition with a mean opening pressure of 57.14 ± 68.0 cm water. Finally, all patients underwent MRI and magnetic resonance venography and the results were unremarkable for space occupying lesion and venous sinus thrombosis, respectively.
Management of the idiopathic intracranial hypertension
All 45 patients were started on medical treatment with oral acetazolamide and dosing details were available only for 41 patients (87.2%). The dose was given depending on the severity of symptoms with 19 patients (46.3%) that received 1 g, 11 patients (26.8%) received 750 mg, and 11 patients (26.8%) received 500 mg. Four patients (8.5%) shifted to topiramate because of the lack of response or intolerance to acetazolamide and four patients (8.5%) underwent lumbar-peritoneal shunt because of inadequate control of the disease in despite of the treatment of the medical therapy. Two patients (4.3%) underwent bariatric surgery for further control of the disease [Figure 2].
Figure 2: Treatment used for the included patients. All 45 patients were started on medical treatment with oral acetazolamide and dosing details were available only for 41 patients (87.2%)The different response rates to acetazolamide based on the given doses are detailed in [Table 3]. The subjective response rates were 72.7%, 63.6%, and 89.5% among patients receiving 500, 750, and 1000 mg, respectively. The objective response rates, with a normal optic disc, were 72.7%, 81.8%, and 63.2% among patients receiving 500, 750, and 1000 mg, respectively. There was a significant difference (P = 0.023) among patients' objective response rates, which was determined by the treating physician, in relation to the dose used; however, this was not the case regarding the subjective response, which was based on the patient's own beliefs (P = 0.162).
Visual acuity and visual field changes
The best-corrected visual acuity of 6/6, in the right eye, changed from 20 eyes on presentation to 28 eyes at 3 months and 21 eyes at 6 months. This change was significant from the baseline to 3 months interval (P = 0.046). However, it dropped to an insignificant level at 6 months (P = 0.058). For the left eye, the best-corrected visual acuity of 6/6 changed from 21 eyes on presentation to 22 eyes at 3 months and 19 eyes at 6 months. This change was insignificant from the baseline to 3 months interval (P = 0.145); however, it was found significant at 6 months (P = 0.035). For both eyes, the change in visual acuity across all assessment points was statistically significant [Figure 3]. For the visual field findings, there were no significant changes among all of the compared assessment points by comparing the visual fields before and after treatment [Table 4].
Figure 3: (a) Comparison of visual acuity in right eye. (b) Comparison of visual acuity in left eye. RT: Right eye, LT: Left eye, VA: Visual acuity Discussion In the present study, we aim to report the demographics, clinical features, medications, and visual affection and prognosis of our IIH population in Jeddah, Saudi Arabia. Our results showed that most of our patients were females (91.5%) and young (within the second and third decades of their lives). This is consistent with the results of previous studies.[18],[19],[20],[21],[22],[23] The correlation between IIH and female patients remains unclear with many suggestions have been made. For instance, it has been suggested that gender-specific hormones might have an important role in the pathophysiology and development of IIH.[24] It was also observed that IIH is not only more prevalent in females but also is strongly associated with obesity[18] and hypertension.[12],[18] On the other hand, Mezaal and Saadah did not report obesity as a strong actor. Instead, they reported headache and bilateral papilledema to be strongly associated with IIH.[11] The identification of obesity as a risk factor can be furtherly supported by the fact that increased adipose tissue mass in females might alter the hormone status in their bodies, which might have a role in the development of IIH. However, the correlation between hormonal differences among both genders of patients with IIH has not been adequately validated by previous studies.[25],[26],[27],[28]
Moreover, the rate of oral contraceptive administration was low in our study, which also questions the validity of the correlation between the hormonal status and the pathophysiology of IIH as previous studies did not also support the correlation.[11],[29] Similarly, steroids administration was reported by a small portion of our study participants. Although the evidence does not support the presence of a correlation between steroids use and IIH,[30] previous studies reported that steroids withdrawal is significantly correlated,[31] which can be explained by the induced adrenocortical insufficiency.[32]
Regarding the symptomatology of our patients, the headache was the most common symptom, which is consistent with the findings of many previous studies.[18],[23],[33],[34] Rudnick and Sismanis[35] reported that nausea, vomiting, and visual disturbances and headache. Mezaal and Saadah also reported headache, and bilateral papilledema to be strongly associated with IIH.[11] TVOs and reduced visual acuity were the second and third most prevalent symptoms in our study. The reported prevalence of TVOs in the literature was high compared to our findings.[18],[34],[36] Furthermore, we reported visual acuity reduction, which was not reported previously in the literature. The prevalence of diplopia (14.9%) is similar to the results of previous studies.[18],[37] The involvement of vision in IIH patients is probably attributable to the underlying optic neuropathy and papilledema. The pattern of the latter is usually symmetrical and bilateral but can sometimes be asymmetrical or unilateral.[38] Papilledema was found symmetrical bilaterally in almost all of our patients (95.7%), which is similar to other studies.[18],[39],[40] These findings might help in suspecting the presence of IIH and should be considered to establish an early diagnosis.
Regarding the management of IIH, most patients used acetazolamide, which is used to reduce the production of CSF, and consequently, reduce the pressure. We have noticed that a dose of 1 g of acetazolamide was significantly associated with the objective response than other doses, which is consistent with the literature.[41] We also noticed that the assessed visual acuity was significantly different among the three follow-up points for both eyes, while the assessed visual field status was not. In contrast, significant visual field improvement was reported by the IIH Treatment Trial.[10] The visual field defects were found in 46.7% of our patients with 21.3% being inferonasal defects. The rate of visual field defects in this study was higher than those reported in Kesler's et al. study[21] but lower than Alkali's et al. study.[12] The early and frequent assessment of visual field defects is important in these patients as such defects usually develop in a stealthy pattern as a result of the initial peripheral affection of the peripheral vision, while the central field might be spared for late stages, which leaves the affected patients unaware of the underlying condition and the progressive complications.[12],[23] This is supported by the higher prevalence of noncentral visual field defects in our study and others than the central ones.[21]
Other second-line medications include topiramate, furosemide, and corticosteroids. Topiramate is a less potent carbonic anhydrase inhibitor but is especially helpful in patients with chronic headaches. Furosemide is used in patients who cannot tolerate acetazolamide or topiramate. A short course of high-dose intravenous corticosteroid is beneficial for patients presenting with severe papilledema and vision loss (fulminant IIH). Lifestyle modifications including weight reduction and discontinuation of any offending medication are helpful adjuvant to medical therapy.[42] Surgical interventions might be needed in some cases that developed persistent and progressive symptoms with no response to the highest dose of the medical therapy.[6],[43] In the present study, 12.8% were indicated for surgery, which is similar to the rates that were reported by previous studies.[44],[45] Shunting procedures have been recently increasingly reported for the management of IIH.[46] Treatment outcome measurements were tested in different clinical trials showed that treatment reports of both subjective and objective outcomes is not necessary to make a clearer data result.[47],[48] However, the data in the literature regarding the difference between subjective and objective outcome measurement in ophthalmology are very scarce and need further future studies.
The findings of this study might be limited by the small number of included patients. Moreover, the study design might be another limitation as some of the reported outcomes might require randomization of patients to properly assess the outcomes. The effect of the baseline characteristics might have also affected the results. Consequently, the adjustment of these variables should be considered in the future investigations.
ConclusionThe present study shows that IIH-related papilledema is common in young female patients. We also found that headache, TVOs, and reduced visual acuity were the most common symptoms in our IIH population. Continuous monitoring of IIH is significantly efficacious and should be considered to enhance the prognosis of IIH-related complications. Besides, visual acuity was significantly different among the three follow-up points for both eyes, while the visual field status was not. This indicates that the visual status should be frequently monitored in these patients.
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Conflicts of interest
There are no conflicts of interest.
References
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