To determine the prevalence of antiphospholipid antibodies and other immunologic abnormalities
in patients with occlusive retinal vascular events, exempt from conventional risk
factors of retinal thrombosis.
Forty patients with retinal vascular occlusion (26 with retinal vein occlusions, eight
with arterial occlusions, two with combined venous and arterial occlusions, and four
with venous occlusions plus vasculitis), free of main accepted risk factors for retinal
thrombosis, were prospectively screened for antiphospholipid antibodies (anticardiolipin-antibodies
and lupus anticoagulant) and other immunologic abnormalities. Fourteen patients were
younger than 50 years. Prevalence and mean values of antiphospholipid antibodies (aPL)
were compared with those in a homogeneous control group of 40 patients.
The prevalence of antiphospholipid antibodies in the study group was 22.5% (nine of
40). Comparison with control group prevalence (5% [two of 40]) showed a statistically
significant difference (P = .04). Six patients in the study group disclosed positivity
for IgG-anticardiolipin antibodies, one patient for IgM anticardiolipin antibodies,
and two patients for both isotypes IgG and IgM anticardiolipin antibodies. The antibody
assay for lupus anticoagulant was negative for all patients. Three patients were diagnosed
as having primary antiphospholipid antibody syndrome and are undergoing systemic anticoagulant
therapy. Relevant immunologic abnormalities were also found (27.5% with antinuclear
antibodies, 35% with elevation of circulating immune complexes, 35% with complement
deficiency, 30% with positive rheumatoid factor, and 17.5% with positive C-reactive
protein). Thirteen patients (32.5%) had more than four parameters altered. No significant
association was found between prevalence or mean values of anticardiolipin antibody
and patients younger than 50 years.
The high prevalence of anticardiolipin antibodies in patients with vaso-occlusive
retinopathy exempt from conventional risk factors, and the relevant diagnostic and
therapeutic implications, lead us to recommend a systematic search for specific antiphospholipid
antibodies in such patients.