Objective: To report ocular complications of Rift Valley fever (RVF) during its first reported outbreak in southwest Saudi Arabia in autumn 2000.
Design: Cross-sectional study of patients in a referral hospital.
Participants: One hundred forty-three consecutive patients with confirmed RVF serologic test results and ocular lesions were enrolled in the study.
Methods: Hospitalized patients (n = 30) and outpatients (n = 113) with clinical symptoms consistent with RVF, positive RVF serologic test results, and ocular abnormalities were studied. Ophthalmologic examinations, including fundus photography and fluorescein angiography, were performed. Patients were followed up at regular intervals to determine the prognosis and outcome of identified ocular abnormalities.
Main outcome measures: Visual acuity at initial presentation and course of anterior and posterior segment complications.
Results: Among 143 patients (78% males; mean age, 53.2 years), 212 eyes were affected, comprising 47 eyes in 30 inpatients and 165 eyes in 113 outpatients. The mean interval between the onset of RVF and visual symptoms ranged from 4 to 15 days (mean, 8.8 days). Macular or paramacular retinitis was identified in all the affected eyes (n = 212) at the time of initial assessment. Lesions included retinal hemorrhages (40%), vitreous reactions (26%), optic disc edema (15%), and retinal vasculitis (7%). Anterior uveitis was present in 31% of outpatients. Fluorescein angiography of the retinitis showed early hypofluorescence with late staining of retinal lesions and blood vessels. Initial visual acuity was less than 20/200 in 80% of eyes in the outpatient group; their vision improved, deteriorated, or remained the same in 13%, 15%, or 72%, respectively. Evaluation at the last follow-up showed macular (60%) or paramacular (9%) scarring, vascular occlusion (23%), and optic atrophy (20%) in the outpatient group.
Conclusions: Rift Valley fever was associated with major ocular morbidity. Ocular manifestations of RVF occurred with a relatively higher frequency than reported up to now and were not limited to severe infections. Rift Valley fever affects the uvea and posterior chorioretinal area and is associated with permanent visual loss resulting from macular and paramacular scarring, vascular occlusion, and optic atrophy. The study demonstrated for the first time that transient nongranulomatous anterior uveitis is associated with RVF.