Case Presentation: An 86 years old male with a history of pulmonary fibrosis, HTN, CHF, RA, valve replacement presented after left eye transient visual loss and exertional dyspnea. He reported an episode of painless vision loss in the left eye, felt like a grey curtain was pulled down over his left eye and lasted about 30 seconds. He had similar episodes of vision loss 3-4 times during the past year. Physical exam showed lower extremities pitting edema and bilateral lung crackles, with negative neurologic exam. Ophthalmologic examination was concerning for vasculitis due to narrow and tortuous vessels with possible impending vein or artery occlusion. Laboratory studies showed decreased kidney function with Cr 2.3 from a baseline of Cr-1.5, with proteinuria and hematuria. The patient had positive ANCA and MPO antibody (P-ANCA 1:160 ,MPO of 55 by EIA) with elevated ESR > 120 and CRP of 2, A kidney biopsy was performed which showed Pauci-immune (ANCA associated) necrotizing and crescentic glomerulonephritis. We were facing a diagnostic dilemma as we were uncertain if the same process was involving the retina and his kidneys especially since retinal vasculitis is unusual. The patient had been started on 60 mg of prednisone daily and he responded well with resolution of eye symptoms. He was given one dose of Rituximab in the hospital and was discharged home with prednisone 20mg PO daily. This successful therapeutic trial convinced us we were dealing with the same vasculitic process involving the eye and kidneys.
Discussion: ANCA associated vasculitis (AAV) is a systemic autoimmune disease affecting small size blood vessels. It mostly involves the lungs, ear, nose, throat and kidneys. AAV can also affect the eye, usually in the anterior chamber presenting as Conjunctivitis, uveitis, scleritis or Ulcerative keratitis. Posterior chamber retinal involvement is extremely rare. We present a case of AAV involving the retina.
Conclusions: Rates of retinal vasculitis are extremely low. A 10-year retrospective study revealed only 14 cases of retinal vasculitis. In other studies, rates of retinal involvement in patients with systemic vasculitis was reported as 0.5 – 2%. Retinal vasculitis can present with broad visual disturbances: floaters, blurry vision, scotomas and even sudden transient visual loss depending on the area of ischemia and vessel involvement. Early treatment will be crucial to avoid vision loss and other organ involvement as well as life-threatening complications. When facing a diagnostic dilemma, we must consider if we need to apply Hickam’s dictum or Occam’s razor. Occam’s razor suggests that the simplest explanation is the most likely implying a diagnostician should assume a single cause for multiple symptoms. One form of Hickam’s dictum states: “A man can have as many diseases as he damn well pleases.” In this case, Occam’s razor wins over Hickam’s Dictum.