Page 370 - The Vasculitides, Volume 1: General Considerations and Systemic Vasculitis

344 Sarah Conway and David S. Younger

hyaline-like necrosis in the media which rapidly spreads to the adventitia and intima, and
infiltration by neutrophils, eosinophils, lymphocytes and plasma cells. This is followed later
by proliferation of fibroblasts that can thicken the intima and occlude vascular lumina [57].

Although ocular manifestations are not a part of the diagnostic criteria for PAN, they
occur in 10% to 20 per cent of patients [58] either due to the direct effects of arteritis that
results in vascular ischemia, or as a secondary effect of renovascular hypertension with
subsequent retinal edema, transudates, hemorrhages and cystoid body formation [59]. The
most common arteries affected are the posterior ciliary arteries and choroidal vessels, which
can result in choroidal infarcts and exudative retinal detachments [59]. Conjunctival and
anterior uveal involvement has also been reported [60]. Orbital involvement may result in
exophthalmos, optic nerve involvement in visual loss, ocular vessel involvement in
episcleritis, necrotizing scleritis, and corneal and scleral ulcers [61]. In an analysis of 393
patients with PAN [62], 42 (10.7%) patients had ophthalmologic manifestations of which
blurred vision was the most common so noted in 13 of 42 (31%) patients, followed by
conjunctivitis in 8 (19%) patients, retinal exudates in 8 (19%) patients, and retinal vasculitis
in 7 (17%) patients. Other less common manifestations included uveitis in 5 (12%) patients,
episcleritis in 4 (10%) patients, thrombosis in 4 (10%) patients, keratitis and optic neuropathy
each in 3 (7.1%) patients, retinal hemorrhages in 2 (5%) patients, and oculomotor nerve palsy
in 1 (2%) patient. A study on 348 patients with PAN [63] noted ophthalmologic
manifestations in 30 (8.6%) patients, consisting of retinal vasculitis, retinal exudates, or both
in 15 (4.3%) patients; conjunctivitis or keratitis in 12 (3.4%) patients, uveitis in 3 (0.8%)
patients, and blurred vision in 2 (0.6%) patients. There was little difference in the frequency
of ophthalmologic manifestations in those with or without HBV-related PAN, so noted
respectively in 10% versus 7% of patients. Moreover, visual symptoms were the presenting
manifestation of PAN in several reported patients, including one with thrombocytosis and
acute blindness secondary to central retinal vein thrombosis [64], others with visual loss due
to retinal vasculitis [59] and bilateral choroidal vasculitis [65], and another patient with
dacryoadenopathy [66].

Reports of fundoscopic examination findings in patients with PAN are varied and include
papilledema, macular star formation, cotton-wool spots, retinal or subhyaloid hemorrhages,
retinal exudates, vascular occlusion of the central retinal artery, and irregularity of the retinal
arteries with or without aneurysm formation [59]. Retinal fluorescein angiography may also
be particularly helpful in the diagnosis and management of PAN. Acute multifocal choroidal
ischemia is a common feature seen on fluorescein angiography in patients with PAN, yet very
rare in the general population, presumably because the degree of vasculitis is sufficiently
severe to affect the choroid [67]. Other common features on fluorescein angiography in PAN
include retinal vasculitis with multiple arterioral and capillary occlusions [67].

Although there are few studies of the effect of corticosteroid treatment on the ocular
manifestations of PAN, Nanjiani [58] reported treatment of bilateral optic neuritis, and
circumscribed posterior choroiditis with serous retinal detachment with corticosteroids that
improved systemic but not ocular manifestations. Akova and colleagues [68] described
responsiveness of a spectrum of ocular findings including scleritis, peripheral ulcerative
keratitis, nongranulomatous uveitis, retinal vasculitis, pseudotumor of the orbit, and central
retinal artery occlusion in five patients, four of whom responded to combination
corticosteroid and cyclophosphamide or azathioprine therapy.

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