Corticosteroids for toxoplasma infection in the eye

What is the aim of this review?
The aim of this Cochrane review was to find out if using medication (corticosteroids) to reduce swelling (inflammation) alongside standard treatment of toxoplasmosis in the eye led to quicker symptom relief and better vision, compared with standard treatment alone. Cochrane researchers searched for all relevant studies to answer this question and found no studies.

Key messages
There is currently no evidence for or against using corticosteroids, in addition to standard treatment, to speed up recovery and prevent visual loss in people with toxoplasmosis in the eye.

What was studied in this review?
Toxoplasmosis is an infection caused by a parasite called Toxoplasma gondii. People can get toxoplasmosis by eating meat that has not been cooked properly, or by eating food or drinking water contaminated with pooh (feces), in particular, cat feces. Toxoplasmosis can affect different parts of the body, including the eye. Not everyone infected by toxoplasma will get symptoms in the eye. However, some people can be affected badly, and can have severe vision loss.

People with toxoplasma infection usually take either anti-parasite medications or antibiotics that kill the parasite. They may also use corticosteroids to reduce the swelling in the eye (inflammation). Using corticosteroids may lead to quicker symptom relief and better vision.

What are the main results of the review?
Cochrane researchers searched multiple electronic databases for studies of the addition of corticosteroids to standard treatment for toxoplasmosis in the eye. They found no relevant studies

People affected by toxoplasma, and doctors and nurses treating them, need evidence as to whether it is useful to take corticosteroids for toxoplasmosis in the eye. They need more information on how much to take, for how long, and when to start taking them alongside standard treatment. Future studies need to collect information on outcomes relevant to people affected by the condition, such as the time it takes to recover from signs and symptoms of vision loss.

How up-to-date is this review?
Cochrane researchers searched for studies that had been published up to 7 December 2016.

Authors' conclusions: 

Although research has identified a wide variation in practice regarding the use of corticosteroids, our review did not identify any evidence from randomized controlled trials for or against the role of corticosteroids in the management of ocular toxoplasmosis. Several questions remain unanswered by well-conducted randomized trials in this context, including whether the use of corticosteroids as an adjunctive agent is more effective than the use of anti-parasitic therapy alone; if so, when corticosteroids should be initiated in the treatment regimen (early versus late course of treatment), and what would be the best dose and duration of steroid use.

Read the full abstract...
Background: 

Ocular infection caused by Toxoplasma gondii, a parasite, may result in inflammation in the retina, choroid, and uvea, and consequently lead to complications such as glaucoma, cataract, and posterior synechiae.

Objectives: 

The objective of this systematic review was to assess the effects of adjunctive use of corticosteroids to anti-parasitic therapy versus anti-parasitic therapy alone for ocular toxoplasmosis.

Search strategy: 

We searched CENTRAL (which contains the Cochrane Eyes and Vision Trials Register (2016; Issue 11)), MEDLINE Ovid, Epub Ahead of Print, In-Process & Other Non-Indexed Citations, MEDLINE Ovid Daily (January 1946 to December 2016), Embase (January 1980 to December 2016), Latin American and Caribbean Literature on Health Sciences (LILACS (January 1982 to December 2016)), the ISRCTN registry (www.isrctn.com/editAdvancedSearch), ClinicalTrials.gov (www.clinicaltrials.gov), and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP; www.who.int/ictrp/search/en). We used no date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 7 December 2016.

Selection criteria: 

We had planned to include randomized and quasi-randomized controlled trials. Eligible trials would have enrolled participants of any age who were immunocompetent and were diagnosed with acute ocular toxoplasmosis. Included trials would have compared anti-parasitic therapy plus corticosteroids versus anti-parasitic therapy alone, different doses or times of initiation of corticosteroids.

Data collection and analysis: 

Two authors independently screened titles and abstracts retrieved through the electronic searches. We retrieved full-text reports of studies categorized as 'unsure' or 'include' after we reviewed the abstracts. Two authors independently reviewed each full-text report for eligibility. Discrepancies were resolved through discussion.

Main results: 

We identified no completed or ongoing trial that was eligible for this Cochrane review.