Acute ocular toxoplasmosis in 49-year-old
A 49-year-old male patient who had been experiencing blurred vision and glare in his left eye for one week came to the ophthalmology clinic. He did not show signs of any systemic symptoms. An ophthalmologic examination revealed that the left eye’s visual acuity was 20/200 and that the anterior chamber had a minor case of granulomatous uveitis. An ophthalmoscopic examination revealed significant vitreous inflammation and focal chorioretinitis. The latter condition caused a bright-white reflection, or “headlight in the fog” image. The right eye’s checkup revealed nothing abnormal. Acute ocular toxoplasmosis was identified as the cause. The patient claimed to have had contact with his pet dog, but not with any other animals or raw or undercooked meat. Doctors diagnosed the patient with acute ocular toxoplasmosis.
The most typical infectious cause of posterior uveitis is ocular toxoplasmosis. It may cause vision alterations that are accompanied by unilateral chorioretinitis and vitritis, or it may not cause any symptoms at all, in which case chorioretinal scars are subsequently discovered by chance. Ocular toxoplasmosis is diagnosed clinically, though in some instances serologic testi ng may help to confirm the diagnosis. Systemic glucocorticoid medications and oral antibacterial therapy were started as treatments. The left eye’s vitreous inflammation had subsided at the follow-up visit a month later, but the visual acuity had not changed from 20/200.
The pathogen Toxoplasma gondii affects both warm-blooded animals and humans
The zoonotic pathogen Toxoplasma gondii is an obligatory intracellular parasite that affects both warm-blooded animals and humans. T. gondii is thought to infect humans on a chronic basis in about one-third of all countries. The disease’s incidence and the causes of infection, however, fluctuate among geographical areas with various toxoplasmic habitats, including various climatic conditions, eating habits, and levels of hygiene.
Ocular toxoplasmosis is caused by Toxoplasma gondii (T. gondii), an obligate intracellular protozoan parasite that may infect all warm-blooded vertebrates, including humans. One of the most common causes of infectious uveitis worldwide is T. gondii. However, a majority of those infected show no symptoms at all after infection. It has further been discovered that certain factors, like immunosuppression or congenital disease, can cause severe sickness. The most common symptoms of ocular toxoplasmosis are posterior uveitis, a unilateral chorioretinal lesion, and vitritis. Primary infection during pregnancy can result in a number of serious consequences, such as foetal mortality, congenital deformities, or, later in the pregnancy, milder infections of neuronal tissues, for example of the brain or retina.
A majority of cases with ocular involvement are postnasal acquired infections
The majority of cases with ocular involvement are most likely postnatal acquired infections, despite the fact that ocular toxoplasmosis in adults was previously thought to be a recurrence of congenital illness. However, both infection routes can result in blindness and serious ocular damage. Positive serology can aid in defining an accurate diagnosis when the characteristic clinical symptoms are quickly identified; however, unusual manifestations might provide diagnostic challenges that ultimately result in misdiagnosis (for example, in immunocompromised patients) and ineffective treatment.
In most cases, retinochoroiditis—the most common sign of active intraocular inflammation in people with ocular toxoplasmosis—is sufficient to establish a clinical diagnosis without the need for additional diagnostic tests. Retinochoroiditis frequently presents with vitritis, reactive granulomatous choroiditis, focal necrotizing granulomatous retinitis, and even inflammatory activity of the anterior segment. However, a lot of instances could exhibit significant clinical variances that make diagnosis challenging. Reactivations can occur at any moment following the initial infection as a result of intraretinal cyst ruptures, which cause a rapid localised immune response. It must be emphasised that the absence of posterior segment scarring does not rule out congenital toxoplasmosis and is not pathognomonic of a recent toxoplasmic infection.
Anterior uveitis Whether granulomatous or non-granulomatous, anterior segment inflammation can range from a mild anterior chamber to a severe anterior uveitis. The underlying retinitis may be hidden by severe inflammation. Iris synechiae that are severe can result from delayed diagnosis and ongoing inflammation. Intense anterior chamber inflammation can also result from retinochoroiditis close to the ora serrata.
Source: NEJM
