Recurrent Toxoplasmic Retinochoroiditis Research Articles

Long-term Results of Trimethoprim-Sulfamethoxazole Versus Placebo to Reduce the Risk of Recurrent Toxoplasma gondii Retinochoroiditis

To compare the effects of 1 year of treatment with trimethoprim-sulfamethoxazole (TMP-SMZ) vs placebo in reducing the risk of recurrence of toxoplasmic retinochoroiditis during a 6-year follow-up period. Randomized, double-masked clinical trial. This cohort included 141 subjects recruited in Campinas, Brazil. The inclusion criterion was unilateral active recurrent toxoplasmic retinochoroiditis. All subjects were treated with 1 dose of TMP-SMZ (160mg/800mg) twice daily for 45days, and all lesions healed after this treatment. After this initial treatment, subjects were randomly assigned to group 1 (1 TMP-SMZ dose every other day for 311days) or group 2 (1 identical placebo tablet containing starch with no active ingredients every other day for 311days). Between the second and sixth years of follow-up appointments, none of the subjects received treatment unless a new recurrence episode had occurred. The primary outcomes were recurrent toxoplasmic retinochoroiditis within the first year of follow-up and recurrent toxoplasmic retinochoroiditis in the 6 years of follow-up. The cumulative probability of recurrence 1, 2, 3, 4, 5, and 6 years after the initial infection was, respectively, 13.0% (9/69), 17.4% (12/69), 20.3% (14/69), 23.2% (16/69), 26.1% (18/69), and 27.5% (19/69) in the placebo group and 0%, 0%, 0%, 0%, 0%, and 1.4% (1/72) in the TMP-SMZ group (P < .001; log-rank test). There were 3 cases (3/69; 4.3%) of multiple recurrences in the same individual in the placebo group. No treatment-limiting toxicity or side effects were observed in either group. New recurrences were more frequent among female subjects. TMP-SMZ may be used safely for prophylaxis of recurrent toxoplasmic retinochoroiditis and may provide long-term benefits.

Trimethoprim-Sulfamethoxazole Versus Placebo in Reducing the Risk of Toxoplasmic Retinochoroiditis Recurrences: A Three-Year Follow-up

To compare the effects of 1 year of treatment with trimethoprim/sulfamethoxazole (TMP-SMZ) vs a placebo in reducing the risk of toxoplasmic retinochoroiditis recurrences during a 3-year follow-up period. Randomized, double-masked clinical trial. This cohort included 141 volunteers recruited in Campinas, Brazil. Inclusion criterion was unilateral active recurrent toxoplasmic retinochoroiditis. All volunteers were treated with 1 tablet of TMP-SMZ (160 mg/800 mg) twice daily for 45days, and all lesions healed after this treatment. After this initial treatment, the volunteers were randomly assigned to Group 1(1TMP-SMZ tablet every 2days for 311days) or Group 2 (1 identical placebo tablet containing starch with no active ingredients every 2days for 311days). At the second- and third-year follow-up appointments, none of the volunteers received treatment unless a new recurrence episode had occurred. The primary outcomes were recurrent toxoplasmic retinochoroiditis within the first year of follow-up and recurrent toxoplasmic retinochoroiditis within the third year of follow-up. The cumulative probability of recurrence at 1, 2, and 3 years of follow-up were, respectively, 13.0% (9/69), 17.4% (12/69), and 20.3% (14/69) in the placebo group and 0% (0/72) in the TMP-SMZ group (P < .001, log-rank test). There was no case of multiple recurrences in the same individual. No treatment-limiting toxicity or side effects were observed in either group. New recurrences were more frequent among female volunteers. TMP-SMZ may be used safely for prophylaxis of recurrent toxoplasmic retinochoroiditis, with long-term benefits.

Do pregnancy, postpartum period and lactation predispose to recurrent toxoplasmic retinochoroiditis?

BackgrundThe aim of the study was a statistical analysis of the possible effects of pregnancy, postpartum period, and lactation on increased risk for reactivation of toxoplasmic retinochoroiditis.Material/MethodsA retrospective study was undertaken of the clinical records of 661 patients referred with the diagnosis of acute toxoplasmic retinochoroiditis to the Department of Zoonoses and Tropical Diseases, Medical University of Warsaw and to the Department of Ophthalmology, Medical University of Warsaw in the years 1994–2014.This group of inpatients consisted of 213 women of child-bearing age (18 to 40 years). Reactivation of toxoplasmic retinochoroiditis was observed in 24 women aged 15 to 39 years who were pregnant, in the postpartum period, or lactating.To compare the rate of the relapses in pregnant/lactating patients vs. non-pregnant/non-lactating patients, the Fisher exact test was used. Calculations were performed with WinPepi software (Abramson JH (2004) WINPEPI (PEPI-for-Windows) for epidemiologists. Epidemiologic Perspectives & Innovations, 2005, 1: 6).ResultsA total of 28 reactivations of toxoplasmic retinochoroiditis were observed (16 episodes in pregnancy, 4 in the postpartum period, and 8 during lactation) in 24 women aged 15 to 39 years. In 3 women, multiple episodes were reported (in early pregnancy and the postpartum period in 2 women, and during 2 pregnancies and lactation in 1 woman). Statistical analysis showed that the risk of an episode of toxoplasmic retinochoroiditis is 7.4-fold higher in pregnancy compared to the non-pregnant/non-lactating women (p<0.0001).ConclusionsWomen of childbearing age with toxoplasma ocular lesions should be informed by their doctors about possible active recurrences during pregnancy and should be followed carefully by an ophthalmologist when pregnant.

Treating ocular toxoplasmosis: current evidence

The current treatment of ocular toxoplasmosis is controversial. The mainstay of treatment has been pyrimethamine and sulphonamides with or without systemic corticosteroids, but the actual evidence that antibiotics have a beneficial effect in recurrent toxoplasmic retinochoroiditis is unsupported by randomised placebo controlled trials. Thus far there have only been three studies looking at the efficacy of antibiotic treatment, all of which were methodologically weak and two of which were perfomed more than 30 years ago. All studies reported adverse effects from treatment. There is an urgent need for further randomised, double blind, placebo controlled studies for lesions in all parts of the retina and to test the efficacy of adjunctive corticosteroid treatment.

Ocular toxoplasmosis: the influence of patient age

The influence of patient age on various features of ocular toxoplasmosis has been a subject of study for many years. The age at which Toxoplasma gondii infection occurs in different populations is related to socioeconomic factors and studies suggest that ocular toxoplasmosis is a more severe disease at the extremes of age. The prevalence of ocular involvement is markedly different between individuals with congenital and those with post-natally acquired infections. Even among those with post-natally acquired infections, age influences the risk and timing of ocular involvement. The severity of toxoplasmic retinochoroiditis (in terms of lesion size, location and associated inflammation) is also affected by patient age at the time of initial infection or recurrence. The risk of recurrent toxoplasmic retinochoroiditis is influenced by age at the time of initial infection and age at most recent episode of active disease. Understanding of relationships between ocular toxoplasmosis and patient age is incomplete; evidence has often been indirect and in some cases conflicting. The influence of patient age on ocular toxoplasmosis should be studied in a systematic manner to provide a better understanding of disease mechanisms and to provide clinical information that can used to establish better strategies for disease treatment and prevention.

Antibiotics for toxoplasmic retinochoroiditis: An evidence-based systematic review

Purpose To determine the effectiveness of systemic antibiotic treatment for toxoplasmic retinochoroiditis. Clinical relevance Toxoplasma retinochoroiditis is a significant cause of visual morbidity. Multiple different antibiotic regimens are used, but controversy about treatment effectiveness remains. Literature reviewed Searches were conducted of Cochrane Controlled Trials Register, Medline (1966 onward), Embase (1980 onward), Dissertation Abstracts (1861 onward), Lilacs (1982 onward), and Pascal (1984 onward). Pharmaceutical companies were contacted for unpublished data. Any randomized controlled trials that compared antibiotics versus placebo in immunocompetent patients with toxoplasmic retinochoroiditis were retrieved. Primary outcome measures were long-term visual acuity and risk of recurrent retinochoroiditis. Secondary outcomes included duration and severity of acute symptoms, size of the lesion at end of follow-up, and adverse effects of treatment. Results Only 3 studies (total of 173 participants) were randomized controlled trials and hence met the inclusion criteria (level II). All 3 were methodologically poor, and 2 were carried out more than 35 years ago. None reported the effect on long-term visual outcome. We found no evidence for a beneficial effect on the duration and severity of signs of acute toxoplasmic retinochoroiditis (A,II). There was weak evidence for an effect of long-term treatment for chronic recurrent toxoplasmic retinochoroiditis on lesion recurrence. Treatment was associated with adverse effects. Conclusions There is a lack of evidence to support routine antibiotic treatment for acute toxoplasmic retinochoroiditis. Placebo-controlled randomized trials of antibiotic treatment in patients presenting with acute or chronic toxoplasmic retinochoroiditis arising in any part of the retina are required.

The effect of long-term intermittent trimethoprim/sulfamethoxazole treatment on recurrences of toxoplasmic retinochoroiditis

PURPOSE: To determine the effect of long-term intermittent trimethoprim/sulfamethoxazole treatment on recurrences of toxoplasmic retinochoroiditis.DESIGN: Prospective randomized open-labeled interventional clinical trial.METHODS: A total of 124 patients with a history of recurrent toxoplasmic retinochoroiditis were randomized to treatment with one tablet of trimethoprim (160 mg)/sulfamethoxazole (800 mg) (Bactrim F; Roche Pharmaceuticals, Rio de Janeiro, Brazil) every 3 days (61 patients) or to observation without treatment (63 patients) and were followed monthly for up to 20 consecutive months for clinical signs of disease recurrence. A recurrence was defined as a new focus of necrotizing retinochoroiditis with active inflammation either adjacent to or remote from preexisting retinochoroidal scars.RESULTS: Recurrences developed in four (6.6%) treated patients and in 15 (23.8%) controls (P = .01). Treatment was discontinued prematurely in four patients because of mild drug reactions.CONCLUSION: Long-term intermittent treatment with trimethoprim/sulfamethoxazole can reduce the rate of recurrent toxoplasmic retinochoroiditis.

Intraocular inflammatory reactions without focal necrotizing retinochoroiditis in patients with acquired systemic toxoplasmosis

PURPOSE: To describe the occurrence of intraocular inflammatory reactions as the sole ophthalmic manifestation of acquired systemic toxoplasmosis. METHODS: Review of medical records for 10 patients with uveitis and evidence of recent Toxoplasma gondii infection. RESULTS: Patient ages ranged from 3 to 51 years. Ocular symptoms were present in each of eight adult patients. Inflammation was unilateral in nine patients; it manifested as vitreous humor cells and haze (10 patients), anterior chamber cells (seven patients), and retinal vasculitis (seven patients). No patient had necrotizing retinochoroiditis upon initial examination. Inflammation resolved in each of nine patients who had follow-up examinations. Foci of retinitis or inactive retinochoroidal scars were seen in four of these nine patients during follow-up examinations, at intervals of 2.0 weeks to 2.5 years after initial examination. CONCLUSIONS: Retinal vasculitis and associated inflammatory reactions may be the only ophthalmic disorder during the early stages of a newly acquired T. gondii infection. Later development of retinitis or scars consistent with toxoplasmic retinochoroiditis in the same eyes suggests that the initial, isolated inflammation may be caused by the presence of parasites in retinal tissue. These cases may have implications for understanding the original source of retinal infection in patients who have recurrent toxoplasmic retinochoroiditis and for treatment of newly acquired T gondii infection.

Reconsidering the pathogenesis of ocular toxoplasmosis

PURPOSE: To review recent observations regarding the sources of Toxoplasma gondii infection and rates of ocular involvement in cases of infection acquired after birth, and to reconcile them with older observations and widely held beliefs about the pathogenesis of ocular toxoplasmosis. METHOD: A review of pertinent reports from the medical literature. RESULTS: There are several potential sources and routes of infection, including inhalation of spores and ingestion of contaminated drinking water, that were previously unrecognized. Ocular involvement in cases of acquired infection appears to be more common than heretofore believed. A variety of host and parasitic factors may influence rates of ocular infection and the characteristics of ocular disease. CONCLUSIONS: The scars from which recurrent toxoplasmic retinochoroiditis arise may be the result of remote, acquired infections in many cases, rather than the residua of congenital infections, as commonly assumed. A better understanding of the epidemiology of T. gondii infection, as well as the host and parasitic factors that influence disease presentation, is important for developing strategies for prevention and management of ocular toxoplasmosis.

Toxoplasmic Retinochoroiditis: New Insights Provided by Indocyanine Green Angiography

To analyze features of indocyanine green angiography associated with recurrent toxoplasmic retinochoroiditis. Indocyanine green angiography was performed according to a standard protocol and correlated with clinical signs and fluorescein angiography in 12 eyes of 12 consecutive patients with recurrent toxoplasmic retinochoroiditis. In 10 of 12 eyes with recurrent toxoplasmic retinochoroiditis, indocyanine green angiography showed multiple satellite dark dots not seen on fluorescein angiography or clinical examination of the fundus. Indocyanine green angiography shows that recurrent toxoplasmic retinochoroiditis is more widespread than clinically visible lesions indicate. Indocyanine green angiography is useful in assessing the extent of involvement of recurrent toxoplasmic retinochoroiditis and the evolution of lesions and might also provide insights into the pathophysiology of the disease.

Recurrent toxoplasmic retinochoroiditis Significance of perilesional satellite dark dots seen by indocyanine green angiography

Purpose: To suggest an explanation for the satellite dark dots seen by indocyanine green angiography (ICGA) around the main focus of a toxoplasmic retinochoroiditis. Mefhods: The authors analysed the evolution of ICG satellite dark dots in two cases of recurrent toxoplasmic retinocho-roiditis receiving anti-toxoplasmic treatment not including corticosteroids. Results: Both patients had a recurrence on the peripheral aspect of scars from previous retinochoroiditis and were treated with pyrimethamine (50 mg/day) and sulfadiazine (4 g/day) for seven weeks. Resolution of satellite ICG dark dots was observed in both cases on the follow-up ICG angiogram performed at the end of treatment. Conclusion: Resolution of ICG satellite dark dots after anti-toxoplasmic treatment not including corticosteroids tends' to indicate that there is probably an infectious component in these hypofluorescent dots and that they probably do not represent a purely in-flammatory perilesional reaction.

Presumed Toxoplasmic Retinochoroiditis in Four Siblings

Four siblings in an East Indian family showed typical ophthalmoscopic findings of toxoplasmic retinochoroiditis. Serologic data confirmed exposure to Toxoplasma gondii and the results of other tests excluded other etiologic agents. Three siblings had documented episodes of ocular inflammation consistent with recurrent toxoplasmic retinochoroiditis. The fourth sibling developed a de novo lesion following an illness consistent with systemic toxoplasmosis.

Studies on experimental ocular toxoplasmosis in the rabbit. I. The effect of antigenic stimulation.

Attempts to stimulate recurrent inflammation in the eyes of rabbits with experimentally induced toxoplasmic retinochoroiditis by the injection of Toxoplasma antigens were unsuccessful. Introduction of living Toxoplasma organisms into the suprachoroidal space of eyes with healed, experimentally induced, toxoplasmic retinochoroiditis resulted in a lowgrade inflammatory response. These experiments provide evidence which contradicts the hypothesis that recurrent toxoplasmic retinochoroiditis results from the leakage of Toxoplasma antigens into the tissues of a hypersensitized eye.