Challenges in identifying papilledema amid myopic peripapillary atrophy in a patient with idiopathic intracranial hypertension and high myopia: a case report

Abstract

Background

Idiopathic intracranial hypertension (IIH) is a disease entity characterized by elevated intracranial pressure, which usually accompanied by papilledema. However, diagnosing papilledema can be challenging in patients with preexisting ocular conditions, such as high myopia.

Case presentation

A 39-year-old woman with a long-standing history of high myopia presented with visual field constriction. Her visual acuity was decreased in both eyes, and she also reported morning headaches, pulsatile tinnitus, and intermittent periocular pain. Although she was diagnosed with IIH based on a cerebrospinal fluid study, there was no evident papilledema, which may have been masked by myopic changes in optic nerve and peripapillary retinal nerve fiber layer. After treatment for IIH with acetazolamide, her visual field and visual acuity markedly improved, and her symptoms were relieved.

Conclusions

In highly myopic patients, myopic changes in optic nerve head may obscure papilledema, complicating the diagnosis of IIH. This unusual case highlights the need for detailed history taking and a comprehensive clinical evaluation in patients with high myopia. Clinicians should suspect IIH in the presence of symptoms such as pulsatile tinnitus, morning headache, and visual field constriction, even in the absence of evident papilledema.

Background

Idiopathic intracranial hypertension (IIH) is a disease entity characterized by elevated intracranial pressure without an identifiable cause and presents predominantly in young obese females [1]. Papilledema, optic disc swelling, and high intracranial pressure are critical diagnostic indicators of IIH [1]. However, diagnosing papilledema can be challenging in patients with preexisting ocular conditions, such as high myopia [1]. High myopia with a tilted optic disc and an elevated nasal disc, posteriorly displaced or blurred, frequently mimics optic disc swelling. Conversely, the identification of papilledema can be complicated when myopia is accompanied by severe peripapillary atrophy. The literature has documented the diagnostic difficulties encountered in such scenarios, emphasizing the need for a careful approach to timely and accurate diagnosis [2]. This case report aimed to shed light on this diagnostic dilemma through a detailed examination of a patient with high myopia and IIH.

Case presentation

A 39-year-old woman with a long-standing history of high myopia presented with visual field constriction, reported by the patient to have been present for 20 years. She had well-controlled diabetes mellitus, hyperlipidemia, and chronic migraine. She denied any history of trauma and no significant surgical or social history. She reported that peripheral visual field constriction had begun 20 years ago and had worsened over the past two months. She also reported mild to moderate morning headaches, pulsatile tinnitus, and intermittent periocular pain. Her body mass index was 30.14 kg/m², and blood pressure was normal. Neurological examination revealed normal cranial nerve function.

On ocular examination, the best-corrected visual acuity was 20/30 in the right eye with − 9.0 Diopter Sphere, and − 3.0 Diopter Cylinder at 180º axis, and 20/50 in the left eye with − 10.0 Diopter Sphere, -3.5 Diopter Cylinder at 10 º axis. The intraocular pressure measured by air pulsation was elevated in both eyes: 23 mmHg in the right and 25 mmHg in the left. Visual field examination revealed a constricted visual field in both eyes (Fig. 1a). Fundus photography revealed the characteristic features of high myopia, including a tilted disc and peripapillary atrophy (Fig. 1b). Disc swelling was not identifiable in any eye. The average thickness of the retinal nerve fiber layers in both eyes on optical coherence tomography (Cirrus HD-OCT; Carl Zeiss Meditec, Dublin, CA, USA) was within the normal range (Fig. 1c). Macular structures and electroretinography results were normal.

Fig. 1.

Ocular examination results on the initial visit. a Visual field test reveals bilateral concentric visual field contraction. b Fundus photography demonstrates features of high myopia. The peripapillary gamma zone is marked with a white arrow. c Cirrus high-definition optical coherence tomography shows nearly normal thickness of peripapillary retinal nerve fiber layers

Laboratory tests revealed normal complete blood counts, electrolyte levels, liver function, kidney function, and serum angiotensin-converting enzyme levels. Antinuclear, antineutrophil cytoplasmic, anticardiolipin, anti-aquaporin 4, and paraneoplastic antibodies were negative.

Orbital magnetic resonance imaging (MRI) showed no significant abnormalities, including intensity changes, compression, or kinking of the optic nerve. Brain MRI and magnetic resonance venography also revealed no structural defects, hydrocephalus, meningeal enhancement, empty sella, or venous sinus thrombosis.

A cerebrospinal fluid (CSF) study revealed an elevated opening pressure of 27.2 cmH₂O, confirming increased intracranial pressure (IICP). The CSF cell count and biochemistry were normal, and no malignant cells were detected on cytology.

Considering her symptoms and confirmation of elevated CSF opening pressure, treatment with 250 mg of acetazolamide tablets three times daily was initiated for IIH symptom control. After one month, her headache and tinnitus gradually improved. Six months later, her visual field had markedly improved (Fig. 2a), and her visual acuity was 20/25 in both eyes. IOP was 19 mmHg in the right eye and 21 mmHg in the left eye. The tinnitus and periocular pain resolved, and the headache was relieved.

Fig. 2.

Ocular examination results six months after treatment initiation. a Visual field test reveals marked recovery of visual field. b Fundus photography demonstrates severe bilateral peripapillary atrophy, showing no significant change compared to previous images

Discussion and conclusions

In our case, we identified the potential of myopic changes to mask papilledema. These myopic changes include peripapillary atrophy and the peripapillary gamma zone. The peripapillary gamma zone, formed without Bruch’s membrane, can alter the optic disc border [3]. Since papilledema diagnosis relies on the appearance of the optic disc margin, fundus evaluation may be obstructed by myopic changes despite the two conditions being histologically independent. Despite nearly normal peripapillary RNFL thickness on OCT and no neuroimaging signs of IICP, the patient’s history of morning headache, pulsatile tinnitus, and progressive visual field constriction led to the suspicion of IIH and the confirmation of elevated intracranial pressure. Following treatment, there was a notable improvement in all symptoms, including peripheral vision constriction, which, according to the patient’s account, had persisted for over 20 years. It is important to note that, even in highly myopic patients showing RNFL thickness within the normal range on pre-treatment OCT, the possibility of swelling should not be excluded.

This case highlights the diagnostic complexity of IIH in patients with high myopia. However, although the patient reported symptoms for over 20 years, IIH-related symptoms may have been of shorter duration. This case highlights the need for thorough history-taking while acknowledging potential inaccuracies in patient recollections.

The literature also emphasizes the need for clinicians to consider a broader range of symptoms, various imaging techniques, and follow-up examinations for an accurate diagnosis. Sibony et al. highlighted the role of SD-OCT in differentiating between papilledema and “myopic, obliquely inserted disc” (MOID) [4]. Features of MOID on SD-OCT, including nasal elevation, oblique entry of the optic nerve, and peripapillary hyperreflective ovoid mass-like structures that correspond to the nasal halo margin on fundus photography, may provide clues for suspecting myopic changes rather than true papilledema [4]. Issac et al. reported a case of optic disc edema superimposed on atrophy [5]. Funduscopic examination revealed minimal bilateral pallor without evidence of papilledema despite severe hydrocephalus [5]. Although OCT of the peripapillary RNFL showed a normal average thickness at the initial visit, their report also indicates that the typical signs of papilledema may not be distinct when disc edema is superimposed on optic atrophy [5].

This case report has certain limitations. The absence of parameters such as central corneal thickness and axial length potentially limits the comprehensive interpretation of the clinical findings. Additionally, follow-up assessments did not include Cirrus HD-OCT, which could have provided valuable insights into changes in the peripapillary RNFL.

In conclusion, papilledema may not always be apparent in highly myopic patients despite IICP because optic nerve head changes can obscure typical signs. Our case suggests a comprehensive clinical evaluation to diagnose and treat IIH in patients with concurrent ocular conditions such as high myopia. Clinicians should suspect IIH in highly myopic patients with symptoms such as pulsatile tinnitus, morning headache, and visual field constriction, even in the absence of evident papilledema.

Author contributions

K.A.P. have made substantial contributions to the conception, I.J.H. and J.Y.C. wrote the main manuscript text and prepared Figs. 1, 2 and 3. All authors reviewed the manuscript.

Funding

This research was supported by the National Research Foundation of Korea (NRF) grant funded by the Korean Government (MSIT) (RS-2024-00341030) to Kyung-Ah Park.

Data availability

No datasets were generated or analysed during the current study.

Declarations

Ethics approval and consent to participate

Not applicable.

Consent for publication

Written informed consent for the publication of this Case Report was obtained from the patient.

Competing interests

The authors declare no competing interests.