Page 369 - The Vasculitides, Volume 1: General Considerations and Systemic Vasculitis

Ophthalmologic and Neuro-Ophthalmologic Aspects of Vasculitides 343

development of retinopathy, retinopathy was more frequent in those with significantly lower
blood pressures and non-recordable right upper limb blood pressures than in patients without
retinopathy.

Ocular symptoms are typically a late manifestation of disease, with ophthalmic
evaluation occurring on average 55 ± 69 months after disease onset. [29]. An ocular ischemic
syndrome was the initial disease manifestation of TAK in three reported patients ranging in
age from 14 to 42 years, of subacute or chronic progressive onset (43-45) , in whom vascular
imaging was crucial in the etiological diagnosis.

FFA is an important tool in determining the extent of ocular involvement in TAK [46],
and when compared with indirect ophthalmoscopy in 31 eyes with TAK showed no additional
changes in ten eyes without retinal vein dilation on indirect ophthalmoscopy. However, of 7
eyes with dilated retinal veins, FFA revealed additional abnormal findings such as
microaneurysms, arteriovenous shunts, retinal neovascularization, and avascular areas
important in grading the stages of retinopathy. Chun and colleagues (38) noted prolongation
of arm-to-retina circulation time in all 21 (100%) eyes with retinopathy while 14 (67%)
patients had delayed arteriovenous filling time. Similarly Uyama and Asayama [30] noted
that arm to retinal time was delayed by 20 seconds on FFA in patients with retinopathy.

Kerr and colleagues [31] noted a 60% response rate to corticosteroids alone among 60
patients with TAK with an estimated time to remission of 22 months. In the steroid resistant
patients, cytotoxic therapy employing methotrexate and cyclophosphamide induced remission
in another 40% of patients. Jales-Neto and coworkers [47] found that combination
corticosteroid and immunosuppressive therapy led to disease remission in 55% of adult
patients, and in 24% of patients less than age 18 years. Among four patients with TAK treated
with corticosteroids described by Ishikawa [48], one improved from stage 3 to stage 2 TAK,
while another patient developed unilateral blindness, and two others, were stable. Pan-retinal
photocoagulation is an adjunctive therapy used to treat cases of severe retinal ischemia [38],
whereas antiplatelet agents reduced the frequency of arterial ischemic events in patients with
TAK [49]. So noted and treated promptly with corticosteroids, the inflammatory process
underlying ocular manifestations may lead to improvement, however arterial stenoses may
require bypass surgery [50, 51].

Medium Vessel Vasculitis

Polyarteritis Nodosa

This systemic necrotizing vasculitis predominantly affects medium-sized arteries with an
estimated annual incidence of 1.1 cases per 1,000,000 people in Australia [52] to 31 per
1,000,000 people in Sweden [53], and 77 per 1,000,000 people in the hepatitis-B virus (HBV)
endemic area of Alaskan Eskimos [54]. The disorder is slightly more prevalent in males, with
a male-to-female ratio of 1.7 to 1.9:1, and most predominant in patients 40 to 60 years of age,
with an average age at onset of 47 years [55, 56]. The 2012 Revised CHCC [3] distinguished
PAN from MPA, distinguishing it as a necrotizing arteritis of medium or small sized arteries
without glomerulonephritis, or vasculitis in arterioles, capillaries or venules, and unassociated
with antineutrophil cytoplasm antibodies (ANCA). The pathologic findings of PAN include

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