Toxoplasma gondii bradyzoites and tachyzoites isolation from vitreous of atypical necrotizing retinitis

Vitreous Humor Positive for DNA of Human Herpesvirus 7 in Eye With Ocular Toxoplasmosis

The aim of this article was to report our findings in a case of infectious uveitis in which the DNAs of both Toxoplasma gondii and human herpesvirus 7 (HHV-7) were detected in the vitreous fluid. A 31-year-old Brazilian man was examined in our hospital with a one-month history of blurred vision (20/40) in the right eye. He had been diagnosed with ocular toxoplasmosis of the right eye at nine years of age and has had repeated relapses. Because of the persistent vitreous opacities and refractoriness to acetylspiramycin and betamethasone, pars plana vitrectomy was performed. Multiplex PCR of the vitreous sample demonstrated the DNAs for both T. gondii and HHV-7. Trimethoprim/sulfamethoxazole with prednisone was prescribed. Six months after the beginning of the therapy, a resolution of the retinochoroiditis was found and the vision recovered to 20/25. Two months later, we performed a pars plana vitrectomy for an epiretinal membrane. The DNAs of both T. gondii and HHV-7 were not detected in the vitreous fluid and the epiretinal membrane. After continued treatment, the best-corrected visual acuity (BCVA) in the right eye improved to 20/16 and the metamorphopsia was reduced. It is inferred from this work that HHV-7 reactivation can activate refractory infectious uveitis in patients with chronic ocular toxoplasmosis.

Posterior segment findings by spectral-domain optical coherence tomography and clinical associations in active toxoplasmic retinochoroiditis

Toxoplasmic retinochoroiditis is a common, potentially blinding parasitic infection. We sought to define the spectrum and frequency of signs of active toxoplasmic retinochoroiditis by spectral domain optical coherence tomography (SD-OCT), and to identify clinical associations. Ninety eyes of 90 individuals presenting consecutively to a tertiary referral uveitis service with active toxoplasmic retinochoroiditis and gradable SD-OCT scans were evaluated prospectively. SD-OCT features were collated, and associations with lesion location, primary versus recurrent episode, serological status, human immunodeficiency virus infection and best-corrected Snellen visual acuity were explored. Active toxoplasmic retinochoroiditis presented with thickened (65%) and hyperreflective (61%) retina, choroidal thickening (55%) and hyporeflectivity (61%), hyperreflective vitreous dots (80%) and deposits (36%), and posterior hyaloid thickening (35%) on SD-OCT. Most signs occurred with similar frequency across clinical groups. Retinal hyporeflectivity (17%) was significantly associated with a visual acuity of 20/200 or worse at resolution. Our observations demonstrate that active toxoplasmic retinochoroiditis has diverse SD-OCT signs and that none are universally present. Retinal hyporeflectivity—suggesting liquefactive necrosis—predicts poor visual outcome.