Few cases of AMN or PAMM associated with BD have been reported in the literature. Our case, along with others[10], occurred in a quiet eye, while others [7, 11] were reported in the context of uveitis flare-ups.

Hernanz & al [11] described in 2017 a case series of three young to middle-aged patients who developed AMN during active BD. Two of these patients were undergoing treatment tapering and one of them was treatment free. Concomitant ocular inflammation was noted in all cases : anterior uveitis in two patients, anterior uveitis and vitritis in one, and vitritis and a hot disc in another. All patients presented initially with a scotoma that faded or disappeared over time, consistent with previous reports [7].

Treatment consisted of oral or intravenous corticosteroids, depending on inflammation severity and blinding risk, often in combination with immunosuppressive agents.

Recently Batioglu & al [10] described a 23 year old non-compliant male patient presenting with a several-month history of scotoma. OCT imaging demonstrated thinning of the outer nuclear layers, indicative of a sequelae stage, and a capillary dropout on OCT-A. Multifocal ERG revealed a diminished cone response localized to the AMN region. No evidence of uveitis was identified.

OCT-A was not available at the time of presentation. A post-event OCT-A conducted on our patient revealed no evidence of capillary hypoperfusion.

The persistence of the scotoma and capillary dropout, attributable to delayed presentation, underscores the importance of early diagnosis, the connection between systemic and ocular disease, and the need for specialized, personalized care. Ultimately, patient prognosis is contingent upon these factors.

Very recently, Song & al. [9] reported a case of bilateral PAMM associated with peripheral vascular occlusion in a 58-year-old patient with newly diagnosed BD.

This case emphasizes the importance of considering BD in any patient presenting with an ischemic microvascular event such as AMN and PAMM. A thorough history and physical examination to identify potential signs of BD are essential. Conversely, multimodal imaging should be considered for all BD patients with visual complaints, particularly those with scotomas, to screen for AMN or PAMM and any sign of associated uveitis.

SD-OCT and Infrared Reflectance (IR) imaging are convenient, non-invasive modalities for diagnosing AMN. Humphrey Visual Field (HVF) testing can be valuable assessing functional impairment and patient follow up. While FFA and CFP are ineffective to detect AMN, they can be helpful in identifying associated signs of BD posterior uveitis such as papillitis, vascular sheathing, vasculitis, retinal ischemia and vascular occlusion.

In patients with AMN of unknown etiology, a comprehensive medical history should be obtained, inquiring about oral aphthosis, genital ulcers, arthritis, gastrointestinal discomfort and skin lesions. A multimodal imaging including IR, dense scanning SD-OCT and FFA is recommended to identify occult posterior uveitis associated with BD. A referral to internal medicine to conduct a complete physical examination is advisable.

Additionally, brain imaging (angio-CT or angio-MRI) and cerebrospinal fluid analysis are essential in front of any neurological complaint, including febrile headaches, behavioral disorders or meningeal signs. Papilledema should also prompt further investigations for intracranial hypertension secondary to cerebral thrombophlebitis [12].

Notably, up to 30% of patients with ocular BD develop Neuro-Behçet, which can have severe consequences and significantly impact treatment decisions [13].

Numerous risk factors for AMN have been identified in the literature, including toxic exposure (epinephrine, caffeine), coagulopathies (oral contraceptive, pregnancy state) and hypovolemia [10]. These factors contribute to retinal hypoperfusion and subsequent ischemic macular microinfarction.

BD is a multisystemic vasculitis involving arteries and veins of various sizes, characterized by dysfunction and damage [14]. Acute posterior uveitis in BD typically presents as an arteriovenous occlusive vasculitis with hemorrhages, cotton wool spots andvarying degrees of ischemia. On the microvascular level, this phenomenon can support the hypothesized ischemic pathogenesis process of AMN.

Furthermore BD is a prothrombotic state disease [15] potentially contributing to macular microinfarcts.

Given the progressive nature of BD-associated posterior uveitis without aggressive treatment, we recommend high-dose corticosteroid therapy (oral or intravenous pulse therapy according to severity) combined with a first-line immunomodulatory therapy (IMT), such as azathioprine. Biologic agents should be considered promptly if inadequate response [12].

Our patient experienced an active systemic BD inflammatory flare, necessitating immediate immunosuppressive therapy. Notably, the absence of anterior, intermediate or posterior inflammation suggests a potential thrombotic etiology for the AMN.

While the patient was already receiving anticoagulants by the rheumatologist, the potential benefit of anticoagulation specifically for presumed thrombotic AMN remains an open question.

In conclusion, the association between AMN and BD may occur in the context of active systemic disease, though further studies are required to better establish this link. Vigilance appears warranted during inflammatory episodes in BD, as they might contribute to such manifestations. Clinicians could consider BD as a potential differential diagnosis in patients presenting with features suggestive of AMN, and neurological involvement may merit cerebral imaging to exclude other causes. Additionally, the management of posterior uveitis in BD, if present, may benefit from timely and targeted treatment. Further investigations are necessary to refine management strategies for AMN in patients with BD.

This case report has inherent limitations that must be considered. To begin with, as a descriptive study of a single clinical case, the findings may not be generalizable. In addition, OCT-A was not available at presentation, which limited our ability to evaluate vascular changes in greater detail. Moreover, the absence of multifocal electroretinography (ERGmf) and Humphrey visual field (HVF) testing hindered a more comprehensive assessment of functional impairment and monitoring of the patient’s follow-up.