Visual Outcome in Ocular Toxoplasmosis: A Case Series of 30 Patients from Ghana

Abstract

Purpose: To determine visual outcome (low vision and blindness) in patients with inactive ocular toxoplasmosis. Methods: This study employed a cross sectional design involving a series of 30 patients with inactive toxoplasmic ocular lesions. Ophthalmic assessment including best corrected visual acuity (BCVA) measurement, slit lamp biomicroscopy, and dilated fundus examination by indirect ophthalmoscopy was performed on all participants. Ocular toxoplasmosis was diagnosed based on characteristic retinal lesions in addition to a positive serologic testing using commercial ELISA kits. Visual impairment (VI) was determined based on the International Classification of Diseases. Results: Their ages ranged from 16-59 years (mean age of 34.2 ± 14.19), with 19 (63.3%) males and 11 (36.7%) females. There were 33 infected eyes in all (3 patients had bilateral cases). The most common complaint (77%) was blurred vision in the infected eyes. 11 (33%) eyes had mild or no visual impairment (VI category 1), 22 (67%) eyes had low vision (VA<6/18), and 11 (33%) eyes were blind (VA<3/60). Posterior pole (p<0.001) and larger retinal lesions (p=0.04) were the major causes of visual impairment. However, there was no association between visual impairment and the number of lesions occurring in the infected eyes (χ2=3.52, p=0.11). Older patient age was significantly associated with: posterior pole lesions (0.003), larger retinal lesion sizes (p=0.001) and multiple lesions (p=0.001). Only three cases each of strabismus and bilateral involvement suggest that acquired infection is more common in this Ghanaian population. Conclusion: Low vision and blindness were common in Toxoplasma eye infection in our Ghanaian population and that posterior pole and larger retinal lesions rather than multiple lesions were the major causes of reduced vision.