Polyarteritis nodosa initially presenting as ocular motility impairment and diplopia with subsequent development of bilateral central retinal artery occlusion: A case report.

Purpose: Polyarteritis nodosa (PAN) is a systemic vasculitis of unknown etiology affecting medium- and small-sized arteries and can present with varied organ involvement, including ocular manifestations. Here, we report a unique case of PAN that initially presented with diplopia and ocular motility impairment, with subsequent development of bilateral central retinal artery occlusion (CRAO), a rare ocular manifestation of PAN. Observations: A 58-year-old man presented with left abduction impairment and diplopia, which initially improved without intervention. However, similar symptoms recurred in the right eye later. The patient presented to the ophthalmology department and was initially suspected of having orbital myositis related to IgG4 disease owing to elevated IgG4 levels. Subsequently, the patient developed bilateral CRAO, confirmed using fundus fluorescein angiography, resulting in remarkable visual loss. Despite negative autoantibodies, a high inflammatory response, and symptoms suggestive of systemic involvement (myalgia, hematuria, muscle weakness, and gastrointestinal symptoms), PAN was diagnosed following laparotomy for intestinal perforation, revealing vasculitis in the medium-to-small arteries. Conclusions and importance: This case underscores the importance of considering a possible diagnosis of PAN in patients with ocular motility impairments and diplopia, even in the absence of classic systemic symptoms. PAN can rapidly progress to severe visual dysfunction, including bilateral CRAO, as observed in this case. Consequently, early recognition and treatment of PAN are crucial, given its potentially severe complications and poor prognosis. Further, this report contributes to the limited literature on PAN, emphasizing the need for awareness of the rare ocular manifestations of systemic vasculitis.