Azithromycin for ocular toxoplasmosis

Neuroretinitis With Severe Macular Edema in Dual Infection: Challenges in Management

Neuroretinitis is a potentially vision-threatening condition distinguished by swelling of the optic disc followed by the emergence of a macular star pattern. The majority of these clinical observations are typically linked to infections caused by bacteria, parasites, or viruses. We report a case of dual infections in neuroretinitis complicated with severe macular edema. A 49-year-old lady presented with sudden onset left eye blurring of vision of one-week duration. Visual acuity was 6/6 in the right eye and 6/60 in the left eye. There was a left positive relative afferent pupillary defect with impaired optic nerve functions. A fundoscopy of the left eye showed optic disc swelling with a macular star. The right optic disc was also swollen. Vasculitis changes were observed in both posterior poles. The ocular coherence tomography of the left eye revealed the existence of macular edema, subretinal fluids, and an epiretinal membrane that extended from the optic disc to the fovea. Serological examinations were positive for toxoplasma and herpes simplex virus type 1. The patient was started on oral azithromycin, oral acyclovir, and oral corticosteroids. Left macular edema persisted despite the treatment. The patient was given a trial of a single injection of intravitreal ranibizumab. A remarkable reduction of subretinal fluids was seen post-intravitreal injection and continuation of medications. Intravitreal ranibizumab has shown significant outcomes in neuroretinitis with severe macula edema.

The use of azithromycin and pyrimethamine for treatment of cerebral toxoplasmosis in human immunodeficiency virus-infected patients: a systematic review

Purpose

Toxoplasma gondii is a parasite that is widely distributed around the globe and can cause brain inflammation, particularly in immunosuppressed patients such as those diagnosed with human immunodeficiency virus (HIV). This paper reviews the efficacy of azithromycin and pyrimethamine combination therapy for cerebral toxoplasmosis in patients with HIV.

Methods

The scope of the studies included in this review was limited from 1992 to 2022, with studies primarily being randomized, controlled clinical trials available on online scientific journal databases. The authors screened eligible records for review, removing those that did not fit the inclusion and exclusion criteria. The risk of bias of the extracted data was analyzed through the Cochrane risk-of-bias tool for randomized trials.

Results

A broad search of major online databases such as PubMed, Medline, Google Scholar, and Cochrane using keywords, limit fields, and Boolean operators yielded 3,130 articles. After thoroughly screening the search results, two studies were included in this review. Results from the studies included in the review demonstrate that the combination therapy of azithromycin and pyrimethamine is favorable for cerebral toxoplasmosis. However, the net response is less effective than the standard treatment regimen (pyrimethamine and sulfadiazine).

Conclusion

The combination therapy of azithromycin and pyrimethamine is less effective than the standard treatment regimen for maintenance therapy for cerebral toxoplasmosis; thus, administering these medications for this indication must be met with caution.

Unilateral Focal Retinitis as an Initial Manifestation of Cat-Scratch Disease

We report on a case of focal retinitis as the initial manifestation of cat-scratch disease. A 56-year-old Hispanic woman presented for a routine follow-up examination. A fundus examination of the right eye revealed a white retinal lesion along the inferotemporal artery; this lesion was noted to have progressed after one week of observation. On further inquiry, the patient reported she had seven cats at home, some of which were less than six months old and had recently scratched her. She received empirical treatment for focal retinitis with azithromycin (500 mg daily) and valacyclovir (1 g three times daily), which would cover the most common parasitic, viral, and bacterial etiologies. She was lost to a follow-up examination. However, she continued the same dose of antibiotic and antiviral treatment. Upon her eventual follow-up, three months later, it was noted that the lesion had resolved. The initial work-up revealed that she was positive for Bartonella henselae IgM (1:20) and IgG (1:512), as well as for B. quintana IgG (1:256); however, she was negative for B.quintana IgM. At a four-month follow-up appointment, the B. henselae IgM was negative, the IgG had decreased from 1:512 to 1:64, and the B. quintana antibody test was negative for IgM and IgG, all of which are consistent with an adequately treated case of cat-scratch disease. Focal retinitis can be a rare initial manifestation of cat-scratch disease, which should be considered part of the differential diagnosis in cases of focal retinitis, especially in patients with a history of close contact with young cats. Additionally, oral azithromycin may be considered as a treatment for some cases of cat-scratch-associated focal retinitis.

Azithromycin concentration in rabbits' plasma and posterior segment of the eyes following oral drug administration: a dose-finding study for the application in ocular toxoplasmosis

INTRODUCTION

Azithromycin has been used as an ocular toxoplasmosis alternative treatment due to its pharmacokinetic profiles. However, sufficient concentrations to promote toxoplasmosis eradication is still unknown. This study was aimed to evaluate azithromycin levels in rabbits after three regimens equivalent to human doses for ocular toxoplasmosis.

METHODS

Three groups of New Zealand albino rabbits were given one of the following: azithromycin at 26 mg/kg BW daily (Group 1), 26 mg/kg BW every two days (Group 2), and 50 mg/kg BW once weekly (Group 3) for 14 days. Plasma and ocular azithromycin concentrations were examined.

RESULTS

Following 14 days, median ratio of plasma maximum azithromycin concentration to the minimum inhibitory concentration for Toxoplasma gondii (C-max/MIC) for Group 1, and 2 were 51.29, 5.33, while Group 3 was undetected. The median azithromycin concentration in the retina-choroid was higher than the MIC in Group 1 (1356.0 ng/ml) and Group 2 (189.0 ng/ml), but not in Group 3.

CONCLUSION

Azithromycin administered orally at the dose of 26 mg/kg BW daily or 26 mg/kg BW every two days resulted a sufficient criteria of C-max/MIC as well as retina-choroid concentration needed for its parasiticidal activity. However, well-conducted clinical trial is warranted to support its therapeutic potential in ocular toxoplasmosis.

Comparison between the areas of scarred and active toxoplasmic retinochoroiditis

BACKGROUND/OBJECTIVES

To assess the ratio of scarred/active areas of fundus lesions in patients with presumed ocular toxoplasmosis.

SUBJECTS/METHODS

Retrospective monocentric study of patients with presumed ocular toxoplasmosis seen between May 2004 and February 2018. Patients with a positive anti-Toxoplasma serology presenting characteristic fundus lesions. Cases with images of both baseline active and scarred lesions of the fundus were included. The borders of each active or scarred lesion were delineated on colour photographs by two independent observers and the area of the lesions was calculated using Digimizer 4.2.2 (MedCalc Software, Ostend, Belgium). The interobserver variability of the measures was recorded and their means were used for further calculations. To study the ratio of the area of scarred retinochoroiditis over the area of the baseline active lesion (R).

RESULTS

A total of 171 cases (83 males, 88 females) with a mean age of 31.6 ± 13.8 years were included. The average areas of active and scarred retinochoroiditis were, respectively, 1.32 ± 1.59 and 1.79 ± 2.36 optic disc area. The average ratio between scarred and active areas of retinochoroiditis was 1.36 [range 0.54-2.18]. The administration of a systemic treatment [R = 1.25, p = 0.003], the absence of a pre-existing scar [R = 1.05, p < 0.001] and a peripapillary location of the lesion [R = 0.85, p < 0.001] were each significantly associated with smaller scarred/active area ratios.

CONCLUSIONS

We assessed in a standardized manner the ratio of scarred/active areas of toxoplasmic lesions and showed that the area of scarred lesions was on average slightly larger than the area of active retinochoroiditis.

[Intravitreal clindamycin injection in toxoplasma retinochoroiditis: About 9 cases in the ophthalmology department of the CHU de Bordeaux]

INTRODUCTION

Toxoplasma retinochoroiditis (TRC) is the main cause of posterior uveitis in immunocompetent patients. Several studies have shown safety and efficacy of treatment with intravitreal clindamycin injection in patients with contraindications, inadequate response or side effects with classic oral therapy. The goal of this study is to describe anatomic and functional results of local treatment with intravitreal clindamycin injection.

MATERIALS AND METHODS

We performed an observational, retrospective, single-center study in the ophthalmology service of Bordeaux university medical center between December 2017 and January 2020 on management of toxoplasma retinochoroiditis by intravitreal clindamycin injection. We analyzed the efficacy of this treatment on improvement in visual acuity, decrease in size of the retinal lesion and decrease in macular thickness.

RESULTS

A total of 10 eyes of 9 patients were injected. Only a single injection was required in 9 of the 10 cases. Injections demonstrated improvement in the 3 study criteria; visual acuity went from a mean of 1 LogMAR (1.07±0.77) pre-injection to 0.4 LogMAR (0.43±0.53) at 6 months, lesion size decreased by 51%, and macular thickness decreased by 78μm over the follow-up period.

CONCLUSION

Intravitreal clindamycin injections are safe and effective for the treatment of TRC. They offer an alternative in patients with allergies, side effects or inadequate response to classic oral therapy.

Pediatric uveitis: A comprehensive review

Pediatric uveitis accounts for 5-10% of all uveitis. Uveitis in children differs from adult uveitis in that it is commonly asymptomatic and can become chronic and cause damage to ocular structures. The diagnosis might be delayed for multiple reasons, including the preverbal age and difficulties in examining young children. Pediatric uveitis may be infectious or noninfectious in etiology. The etiology of noninfectious uveitis is presumed to be autoimmune or autoinflammatory. The most common causes of uveitis in this age group are idiopathic and juvenile idiopathic arthritis-associated uveitis. The stepladder approach for the treatment of pediatric uveitis is based on expert opinion and algorithms proposed by multidisciplinary panels. Uveitis morbidities in pediatric patients include cataract, glaucoma, and amblyopia. Pediatric patients with uveitis should be frequently examined until remission is achieved. Once in remission, the interval between follow-up visits can be extended; however, it is recommended that even after remission the child should be seen every 8-12 weeks depending on the history of uveitis and the medications used. Close follow up is also necessary as uveitis can flare up during immunomodulatory therapy. It is crucial to measure the impact of uveitis, its treatment, and its complications on the child and the child's family. Visual acuity can be considered as an acceptable criterion for assessing visual function. Additionally, the number of cells in the anterior chamber can be a measure of disease activity. We review different aspects of pediatric uveitis. We discuss the mechanisms of noninfectious uveitis, including autoimmune and autoinflammatory etiologies, and the risks of developing uveitis in children with systemic rheumatologic diseases. We address the risk factors for developing morbidities, the Standardization of Uveitis Nomenclature (SUN) criteria for timing and anatomical classifications, and describe a stepladder approach in the treatment of pediatric uveitis based on expert opinion and algorithms proposed by multi-disciplinary panels. In this review article, We describe the most common entities for each type of anatomical classification and complications of uveitis for the pediatric population. Additionally, we address monitoring of children with uveitis and evaluation of Quality of Life.

Control of human toxoplasmosis

Toxoplasmosis is caused by Toxoplasma gondii, an apicomplexan parasite that is able to infect any nucleated cell in any warm-blooded animal. Toxoplasma gondii infects around 2 billion people and, whilst only a small percentage of infected people will suffer serious disease, the prevalence of the parasite makes it one of the most damaging zoonotic diseases in the world. Toxoplasmosis is a disease with multiple manifestations: it can cause a fatal encephalitis in immunosuppressed people; if first contracted during pregnancy, it can cause miscarriage or congenital defects in the neonate; and it can cause serious ocular disease, even in immunocompetent people. The disease has a complex epidemiology, being transmitted by ingestion of oocysts that are shed in the faeces of definitive feline hosts and contaminate water, soil and crops, or by consumption of intracellular cysts in undercooked meat from intermediate hosts. In this review we examine current and future approaches to control toxoplasmosis, which encompass a variety of measures that target different components of the life cycle of T. gondii. These include: education programs about the parasite and avoidance of contact with infectious stages; biosecurity and sanitation to ensure food and water safety; chemo- and immunotherapeutics to control active infections and disease; prophylactic options to prevent acquisition of infection by livestock and cyst formation in meat; and vaccines to prevent shedding of oocysts by definitive feline hosts.

Optical coherence tomography angiography findings in macular toxoplasma retinochoroiditis: A case report

Purpose

To report the optical coherence tomography angiography (OCT-A) findings in a patient with macular toxoplasma retinochoroiditis (TRC).

Observations

A 14-year old female presented with a 2-week history of decreased vision of her right eye. Upon presentation, on the right eye, visual acuity was 20/200 and the fundus revealed 2+ vitritis and an active parafoveal area of retinitis superotemporally. Toxoplasma serology revealed positive IgG and negative IgM. Initial treatment consisted of intravitreal clindamycin (1.0mg in 0.1 mL) with dexamethasone (1.0 mg in 0.1 mL) along with oral trimethoprim/sulfamethoxazole, azithromycin and prednisone; of which the trimethoprim/sulfamethoxazole was discontinued 4 days into therapy due to a pruritic rash. Six-weeks after the presentation, the oral prednisone had been tapered off, and all therapy discontinued. The patient had complete resolution of TRC and recovered 20/20 vision. OCT-A analysis of the right macula, performed after completion of treatment, revealed preservation of foveal perfusion along a parafoveal area of ischemia, superotemporally, at the superficial and deep retinal vascular complexes, including the choriocapillaris.

Conclusion and Importance

In macular TRC, OCT-A may help to assess therapeutic outcomes from a vascular perspective. To our knowledge, our case represents the first description in the medical literature of OCT-A findings in macular TRC.

Clinical and Biological Factors Associated With Recurrences of Severe Toxoplasmic Retinochoroiditis Confirmed by Aqueous Humor Analysis

PURPOSE

To investigate clinical and biological factors influencing recurrences of severe toxoplasmic retinochoroiditis (TRC) confirmed by aqueous humor analysis.

DESIGN

Retrospective case series.

METHODS

Retrospective analysis of 87 subjects with severe TRC, proven by positive Goldmann-Witmer coefficient (GWC), Toxoplasma gondii (T. gondii) immunoblot, or T. gondii-specific polymerase chain reaction (PCR) in aqueous humor. Cases with immunosuppression or retinal scars without previous recorded episode were excluded. Time-dependent, clinical, treatment-related, and biological factors were explored by univariate and multivariate shared frailty survival analyses.

RESULTS

Among 44 included subjects (age, 40.4 ± 17.6 years; follow-up, 8.3 ± 2.7 years), 22 presented recurrences. There was 0.11 recurrence/patient/year and mean disease-free interval was 5.0 ± 2.9 years. The risk of recurrence was higher immediately after an episode (P < .0001). Among recurrent cases, the risk of multiple recurrences was higher when the first recurrence occurred after longer disease-free intervals (P = .046). In univariate analysis, the recurrence risk declined with higher number of intense bands on aqueous T. gondii immunoblot (P = .006), and increased when venous vasculitis was present initially (P = .019). Multivariate analysis confirmed that eyes with more intense bands on immunoblot had fewer recurrences (P = .041). There was a near-significant risk elevation after pyrimethamine/azithromycin treatment (P = .078 and P = .054, univariate and multivariate). Intravenous corticosteroid administration, oral corticosteroid administration, aqueous GWC, and T. gondii PCR did not influence recurrences (P = .12, P = .10, P = .39, and P = .96, respectively).

CONCLUSIONS

Recurrences of severe TRC are not random and may be influenced by clinical and biological factors possibly related to blood-retinal barrier alterations. These results may contribute to identifying biomarkers for TRC reactivation.

Treatment of Toxoplasmosis: Historical Perspective, Animal Models, and Current Clinical Practice

Primary Toxoplasma gondii infection is usually subclinical, but cervical lymphadenopathy or ocular disease can be present in some patients. Active infection is characterized by tachyzoites, while tissue cysts characterize latent disease. Infection in the fetus and in immunocompromised patients can cause devastating disease. The combination of pyrimethamine and sulfadiazine (pyr-sulf), targeting the active stage of the infection, is the current gold standard for treating toxoplasmosis, but failure rates remain significant. Although other regimens are available, including pyrimethamine in combination with clindamycin, atovaquone, clarithromycin, or azithromycin or monotherapy with trimethoprim-sulfamethoxazole (TMP-SMX) or atovaquone, none have been found to be superior to pyr-sulf, and no regimen is active against the latent stage of the infection. Furthermore, the efficacy of these regimens against ocular disease remains uncertain. In multiple studies, systematic screening for Toxoplasma infection during gestation, followed by treatment with spiramycin for acute maternal infections and with pyr-sulf for those with established fetal infection, has been shown to be effective at preventing vertical transmission and minimizing the severity of congenital toxoplasmosis (CT). Despite significant progress in treating human disease, there is a strong impetus to develop novel therapeutics for both the acute and latent forms of the infection. Here we present an overview of toxoplasmosis treatment in humans and in animal models. Additional research is needed to identify novel drugs by use of innovative high-throughput screening technologies and to improve experimental models to reflect human disease. Such advances will pave the way for lead candidates to be tested in thoroughly designed clinical trials in defined patient populations.

Management of giant retinal tear and retinal detachment in a patient with active toxoplasmosis retinochoroiditis

Purpose

To describe the management of a giant retinal tear with retinal detachment in a patient with active toxoplasmosis retinochoroiditis.

Results

While receiving systemic medications for toxoplasmosis, the patient underwent scleral buckling, pars plana vitrectomy, and C3F8 gas tamponade without removal of the lens. At last follow-up, best corrected visual acuity was 20/20 with an attached retina and the toxoplasmosis lesion was inactive.

Conclusions

and Importance: Using modern surgical techniques, anatomic and clinical success is possible during active retinochoroiditis.

Pediatric Uveitis

Pediatric uveitis differs from adult-onset uveitis and is a topic of special interest because of its diagnostic and therapeutic challenges. Children with uveitis are often asymptomatic and the uveitis is often chronic, persistent, recurrent, and resistant to conventional treatment. Anterior uveitis is the most common type of uveitis in children; the prevalence of intermediate, posterior, and panuveitis varies geographically and among ethnic groups. Regarding etiology, most cases of pediatric uveitis are idiopathic but can be due to systemic inflammatory disorders, infections, or a manifestation of masquerade syndrome. Ocular complications include cataracts, hypotony or glaucoma, band keratopathy, synechiae formation, macular edema, optic disc edema, choroidal neovascular membranes, and retinal detachment. These complications are often severe, leading to irreversible structural damage and significant visual disability due to delayed presentation and diagnosis, persistent chronic inflammation from suboptimal treatment, topical and systemic corticosteroid dependence, and delayed initiation of systemic disease‒modifying agents. Treatment for noninfectious uveitis is a stepwise approach starting with corticosteroids. Immunomodulatory therapy should be initiated in cases where quiescence cannot be achieved without steroid dependence. Patients should be monitored regularly for complications of uveitis along with systemic and ocular adverse effects from treatments. The goals are to achieve steroid-free durable remission, to reduce the risk of sight-threatening complications from the uncontrolled ocular inflammation, and to avoid the impact of lifelong burden of visual loss on the child and their family. Multidisciplinary management will ensure holistic care of affected children and improve the support for their families.

A prospective randomized trial of azithromycin versus trimethoprim/sulfamethoxazole in treatment of toxoplasmic retinochoroiditis

Purpose

To assess the efficacy of oral azithromycin in the treatment of toxoplasmic retinochoroiditis.

Methods

A randomized interventional comparative study was conducted on 14 patients with ocular toxoplasmosis who were treated with oral azithromycin and 13 patients who were treated with oral trimethoprim/sulfamethoxazole for 6–12 weeks. The achievement of treatment criteria in the two groups and lesion size reduction were considered as primary outcome measures.

Results

The resolution of inflammatory activity, decrease in the size of retinochoroidal lesions, and final best corrected visual acuity (BCVA) did not differ between the two treatment groups. The lesion size declined significantly in all patients (P = 0.001). There was no significant difference in the reduction of the size of retinal lesions between the two treatment groups (P = 0.17).

Within each group, there was a significant improvement in BCVA after treatment; BCVA increased by 0.24 logMAR in the azithromycin group (P = 0.001) and by 0.3 logMAR in the trimethoprim/sulfamethoxazole group (P = 0.001).

Conclusions

Drug efficacy in terms of reducing the size of retinal lesions and visual improvement was similar in a regimen of trimethoprim/sulfamethoxazole or azithromycin treatment. Therefore, if confirmed with further studies, therapy with azithromycin seems to be an acceptable alternative for the treatment of ocular toxoplasmosis.

Ocular toxoplasmosis: background and evidence for an antibiotic prophylaxis

PURPOSE OF REVIEW

The purpose of this review was to provide an overview of current data on antibiotic prophylaxis in ocular toxoplasmosis.

RECENT FINDINGS

Studies showing the prophylactic effect of long-term antibiotics are discussed. Prophylaxis seems to be justified in patients with a high risk of recurrence because of antibiotic's potential side-effects. Therefore, predisposing factors leading to a higher risk of recurrence and the time period during which an antibiotic prophylaxis is most appropriate are reviewed. Finally, a patient-individualized treatment recommendation is summarized.

SUMMARY

In the current literature, two prospective, randomized case-control studies exist, which show the protective effect of an antibiotic prophylaxis. Hematologic, gastrointestinal and dermatologic complications are potential side-effects. Especially during the first year after suffering a recurrence, an antibiotic prophylaxis seems to be justified. The risk of a recurrence is inter alia influenced by the duration of the disease, the immune status of the host and the patient's age. Therefore, an antibiotic prophylaxis should be considered for patients who have recently been infected with ocular toxoplasmosis, for middle-aged and elderly patients and patients with a compromised immune system. This should be discussed with each patient individually, especially if the lesion is close to the macula.

The Effect of Intravitreal Azithromycin on the Albino Newborn Rabbit Retina

Purpose:

To evaluate the effect of intravitreal azithromycin on the retina in a newborn rabbit model.

Methods:

Twelve, two-week old New Zealand albino rabbits were divided into two groups (six in each). The right eyes of six rabbits received 0.75 mg (0.05 mL) azithromycin and the right eyes of the remaining six rabbits 1.5 mg (0.1 mL) azithromycin intravitreally. Left eyes were served as the control and received the same volume of saline. All eyes were enucleated at the third postinjection week. Retinal histology was examined by light microscopy. Apoptosis of the retinal cells was further evaluated by immunohistochemical staining for caspase-3 and in situ terminal deoxynucleotidyl transferase-mediated biotin-deoxyuridine triphosphate nick-end labeling (TUNEL) of DNA fragments.

Results:

Light microscopy demonstrated no retinal abnormalities in all eyes. However, retinal nuclear DNA fragmentation was evident in both study groups (33.6% with 1.5 mg and 21.4% with 0.75 mg azithromycin) with the TUNEL method. TUNEL staining ratio was statistically higher only in the second group treated with 1.5 mg azithromycin when compared to the control group (p=0.01 Mann Whitney U test). The ratio of caspase-3 positive cells in the two study groups was 21.5% and 20.2%, respectively. Caspase-3 staining ratio was statistically higher in both study groups when compared to the control eyes (p=0.00, p=0.00 respectively). The difference of TUNEL staining ratio between the two study groups was statistically significant (p=0.028), but there were no statistically significant differences in the two study groups by caspase-3 staining (p=0.247).

Conclusion:

In newborn rabbits, intravitreal azithromycin injection resulted in an apoptotic activity in the photoreceptor, bipolar and ganglion cells. Immunohistochemical analysis suggested that doses of 0.75 mg and 1.5 mg azithromycin, administered intravitreally might be toxic to the newborn rabbit retina.

A Systematic Review and Meta-Analysis of the Efficacy of Anti-Toxoplasma gondii Medicines in Humans

No effective drug and definitive "gold standard" treatment for Toxoplasma gondii (T. gondii) infection has been available so far, though some medicines have been commonly used in the treatment of T. gondii infection, such as spiramycin, azithromycin, traditional Chinese medicine (TCM), pyrimethamine- sulfadiazine (P-S), trimethoprim-sulfamethoxazole (TMP-SMX), and pyrimethamine-clindamycin (P-C). A systematic review and meta-analysis were performed to compare the efficacies of these conventional medicines in the treatment. Cohort studies for the treatment of acute T. gondii infection were searched from PubMed, Google Scholar, ect. All the cases number for different group extracted from each included literature were input to meta-analysis 3.13 software to calculate the pooled negative conversion rate (NCR), cure rate (CR) or vertical transmission rate based on their sample size and weight. The pooled NCR with 95% confidence intervals (CI) was used to evaluate the overall rate of a diagnosis positive result conversion to a negative result after treatment, which of spiramycin, azithromycin and TCM were 83.4% (95%CI, 72.1%-90.8%), 82.5% (95%CI, 75.9%-87.6%), and 85.5% (95%CI, 71.3%-93.3%) respectively, with no statistical difference between them. The pooled CR with 95% CI was used to evaluate the overall rate of complete disappearance of clinical symptoms for toxoplasmic encephalitis after therapy, which of P-S, TMP-SMX, and P-C were 49.8% (95%CI, 38. 8% -60.8%), 59.9% (95%CI, 48.9%-70.0%), and 47.6% (95%CI, 24.8%-71.4%) respectively, with no statistical difference between them. Primary T. gondii infection in pregnancy was treated mainly with spiramycin alone or combined with other drugs, and the pooled rate of vertical transmission was about 9.9% (95%CI, 5.9%-16.2%) after therapy. Toxoplasmic encephalitis in AIDS patients was usually treated with sulfonamides combined with other drugs and the pooled CR was 49.4% (95%CI, 37.9%-60.9%).

The role of intravitreal trimethoprim/sulfamethoxazole in the treatment of toxoplasma retinochoroiditis

The authors evaluate the role of intravitreal trimethoprim/sulfamethoxazole in the treatment of toxoplasma retinochoroiditis (TRC) in four patients. Intravitreal injection of trimethoprim/sulfamethoxazole 1.28 mg/0.08 mL with dexamethasone 400 µg/0.1 mL was injected weekly or biweekly. After the initiation of treatment, a reduction in intraocular inflammation was observed clinically and on optical coherence tomography within 1 week. Three patients regained visual acuity of 20/20, and one patient improved to 20/40 with residual macular scarring. No evidence of retinal toxicity was noted on full-field electroretinogram. Intravitreal trimethoprim/sulfamethoxazole and dexamethasone combination may be an alternative treatment strategy in patients with TRC.

Sitting at the window to the world--ocular parasites

Parasitic infections cause significant ophthalmic disease, both in developing countries and in the Western world. The parasitic infections Acanthamoeba keratitis, ocular toxoplasmosis, and ocular toxocariasis are responsible for a significant proportion of ocular pathology. Especially in light of the recent increase of immunocompromised (i.e. using immunosuppressants or HIV) and aged populations, parasitic infections of the eye are rising in number. This reviews aims to describe the pathogenesis, symptoms, diagnosis and management of infection, as well as preventative measures for these three parasitic ocular diseases.

Animals are key to human toxoplasmosis

Toxoplasma gondii is an extremely sucessfull protozoal parasite which infects almost all mamalian species including humans. Approximately 30% of the human population worldwide is chronically infected with T. gondii. In general, human infection is asymptomatic but the parasite may induce severe disease in fetuses and immunocompromised patients. In addition, T. gondii may cause sight-threatening posterior uveitis in immunocompetent patients. Apart from few exceptions, humans acquire T. gondii from animals. Both, the oral uptake of T. gondii oocysts released by specific hosts, i.e. felidae, and of cysts persisting in muscle cells of animals result in human toxoplasmosis. In the present review, we discuss recent new data on the cell biology of T. gondii and parasite diversity in animals. In addition, we focus on the impact of these various parasite strains and their different virulence on the clinical outcome of human congenital toxoplasmosis and T. gondii uveitis.

Current treatment of toxoplasma retinochoroiditis: an evidence-based review

Objective. To perform an evidence-based review of treatments for Toxoplasma retinochoroiditis (TRC). Methods. A systematic literature search was performed using the PubMed database and the key phrase "ocular toxoplasmosis treatment" and the filter for "controlled clinical trial" and "randomized clinical trial" as well as OVID medline (1946 to May week 2 2014) using the keyword ''ocular toxoplasmosis". The included studies were used to evaluate the various treatment modalities of TRC. Results. The electronic search yielded a total of 974 publications of which 44 reported on the treatment of ocular toxoplasmosis. There were 9 randomized controlled studies and an additional 3 comparative studies on the treatment of acute TRC with systemic or intravitreous antibiotics or on reducing the recurrences of TRC. Endpoints of studies included visual acuity improvement, inflammatory response, lesion size changes, recurrences of lesions, and adverse effects of medications. Conclusions. There was conflicting evidence as to the effectiveness of systemic antibiotics for TRC. There is no evidence to support that one antibiotic regimen is superior to another so choice needs to be informed by the safety profile. Intravitreous clindamycin with dexamethasone seems to be as effective as systemic treatments. There is currently level I evidence that intermittent trimethoprim-sulfamethoxazole prevents recurrence of the disease.

Auranofin is highly efficacious against Toxoplasma gondii in vitro and in an in vivo experimental model of acute toxoplasmosis

BACKGROUND

The mainstay of toxoplasmosis treatment targets the folate biosynthetic pathways and has not changed for the last 50 years. The activity of these chemotherapeutic agents is restricted to one lifecycle stage of Toxoplasma gondii, they have significant toxicity, and the impending threat of emerging resistance to these agents makes the discovery of new therapies a priority. We now demonstrate that auranofin, an orally administered gold containing compound that was FDA approved for treatment of rheumatoid arthritis, has activity against Toxoplasma gondii in vitro (IC50 = 0.28 µM) and in vivo (1 mg/kg).

METHODS/PRINCIPAL FINDINGS

Replication within human foreskin fibroblasts of RH tachyzoites was inhibited by auranofin. At 0.4 µM, auranofin inhibited replication, as measured by percent infected fibroblasts at 24 hrs, (10.94% vs. 24.66% of controls; p = 0.0003) with no effect on parasite invasion (16.95% vs. 12.91% p = 0.4331). After 18 hrs, 62% of extracellular parasites treated with auranofin were non-viable compared to control using an ATP viability assay (p = 0.0003). In vivo, a previously standardized chicken embryo model of acute toxoplasmosis was used. Fourteen day old chicken embryos were injected through the chorioallantoic vein with 1×104 tachyzoites of the virulent RH strain. The treatment group received one dose of auranofin at the time of inoculation (1 mg/kg estimated body weight). On day 5, auranofin-treated chicken embryos were 100% protected against death (p = 0.0002) and had a significantly reduced parasite load as determined by histopathology, immunohistochemistry and by the number of parasites quantified by real-time PCR.

CONCLUSIONS

These results reveal in vitro and in vivo activity of auranofin against T. gondii, suggesting that it may be an effective alternative treatment for toxoplasmosis.

Pediatric uveitis: An update

Because of their varied spectrum of clinical presentation and difficulty in management, pediatric uveitis remains a challenge to the ophthalmologist. Variations in clinical presentation, difficulties in eye examination, extended burden of the inflammation over quality of life, limited treatment modalities, risk of amblyopia are the main challenges in the management of pediatric uveitis. Pediatric uveitis is a cause of significant ocular morbidity and severe vision loss is found in 25-33% of such cases. This article summarizes the common causes of uveitis in children with special approach to the evaluation and diagnosis of each clinical entity.

Ocular Toxoplasmosis: Controversies in Primary and Secondary Prevention

Ocular toxoplasmosis is the most common cause of posterior uveitis in the United States and worldwide. It commonly follows a relapsing course with the potential for multiple adverse visual sequelae and, rarely, blindness. Both immune-competent and immune-suppressed populations can develop severe relapsing disease. There is considerable debate regarding the initial treatment of ocular toxoplasmosis in both groups, with multiple antiparasitic agents commonly used with little evidence to support any particular regimen. The precise role of corticosteroids in treatment also has yet to be rigorously defined. Secondary prevention is commonly implemented in the immune suppressed population, but there is a lack of level one evidence to support its role in immune-competent patients, though it warrants future investigation.

Ocular toxoplasmosis II: clinical features, pathology and management

The term, ocular toxoplasmosis, refers to eye disease related to infection with the parasite, Toxoplasma gondii. Recurrent posterior uveitis is the typical form of this disease, characterized by unilateral, necrotizing retinitis with secondary choroiditis, occurring adjacent to a pigmented retinochoroidal scar and associated with retinal vasculitis and vitritis. Multiple atypical presentations are also described, and severe inflammation is observed in immunocompromised patients. Histopathological correlations demonstrate focal coagulative retinal necrosis, and early in the course of the disease, this inflammation is based in the inner retina. For typical ocular toxoplasmosis, a diagnosis is easily made on clinical examination. In atypical cases, ocular fluid testing to detect parasite DNA by polymerase chain reaction or to determine intraocular production of specific antibody may be extremely helpful for establishing aetiology. Given the high seroprevalence of toxoplasmosis in most communities, serological testing for T. gondii antibodies is generally not useful. Despite a lack of published evidence for effectiveness of current therapies, most ophthalmologists elect to treat patients with ocular toxoplasmosis that reduces or threatens to impact vision. Classic therapy consists of oral pyrimethamine and sulfadiazine, plus systemic corticosteroid. Substantial toxicity of this drug combination has spurred interest in alternative antimicrobials, as well as local forms of drug delivery. At this time, however, no therapeutic approach is curative of ocular toxoplasmosis.

Azithromycin versus Sulfadiazine and Pyrimethamine for non-vision-threatening toxoplasmic retinochoroiditis: a pilot study

Background

The purpose of this pilot study is to compare the efficacy and tolerance of azithromycin alone as opposed to standard treatment with sulfadiazine and pyrimethamine for active, non-vision-threatening toxoplasmic retinochoroiditis.

Material/Methods

We conducted a prospective, randomized, institutional clinical study comparing azithromycin to sulfadiazine and pyrimethamine for active, non-vision-threatening toxoplasmic retinochoroiditis. Nineteen out of 75 patients fulfilled inclusion criteria and were randomized into 2 treatment regimens. Nine patients were treated with sulfadiazine and pyrimethamine and 10 patients with azithromycin at a dose of 500 mg qd. Main outcome measures assessed were time to sharpening of lesion borders, time to lesion scarring, time to disease inactivity, and treatment tolerance.

Results

Azithromycin monotherapy achieved lesion scarring and disease inactivity in all but 1 patient. Although no statistically significant difference was found between the 2 patient groups as regards main outcome measures for treatment efficacy, all median times to endpoints (days) were longer for the azithromycin group – time to sharpening of lesion borders on clinical evaluation (25.5 vs. 24) and masked evaluation of photographs (30.5 vs. 24), time to lesion scarring on clinical evaluation (73 vs. 47) and masked evaluation of photographs (71.5 vs. 36) and time to disease inactivity (73 vs. 49). Treatment tolerance was significantly better for the azithromycin group (p=0.0005).

Conclusions

Azithromycin monotherapy at a dose of 500 mg per day was shown to be effective and well-tolerated for the treatment of active, non-vision-threatening toxoplasmic retinochoroiditis. Duration of treatment was clinically longer for the azithromycin group.

Fetal therapy of severe symptomatic toxoplasmosis using azithromycin

Severe symptomatic fetal toxoplasmosis rarely occurs after the maternal primary infection of Toxoplasma gondii. We herein report our experience of fetal therapy of symptomatic toxoplasmosis using azithromycin. Ultrasound assessment at 23 weeks' gestation revealed fetal ascites, cardiac effusion, cardiomegaly, enlarged lateral ventricles and thickened placenta. Serum Toxoplasma gondii antibody titer was ×81,920. Toxoplasma immunoglobulin M was 2.4 index (normal, <0.8 index), and immunoglobulin G was ≥240 IU/mL (normal, <6 IU/mL). Maternal oral administration of azithromycin in addition to sulfadoxine, pyrimethamine and acetylspiramycin was conducted. Spontaneous vaginal delivery occurred at 32 weeks and a male infant weighing 2036 g was born. Hepatosplenomegaly, chorioretinitis, hydrocephalus, intracranial calcifications, ascites, and meningitis were confirmed after birth. The infant underwent therapy with pyrimethamine and sulfadiazine. It seems imperative to establish a new drug choice for fetal therapy of severe symptomatic toxoplasmosis in order to reduce the maternal and fetal risks of drug side-effects.

Intravitreal clindamycin and dexamethasone for zone 1 toxoplasmic retinochoroiditis at twenty-four months

PURPOSE

To report the anatomic and functional outcomes of intravitreal clindamycin and dexamethasone for the treatment of zone 1 toxoplasmic retinochoroiditis (TRC). Patients had 1 or more of the following indications for local therapy: intolerance to oral medication, contraindication to oral medication because of pregnancy, lack of response despite oral antimicrobial treatment, or treatment with concomitant oral and local therapy to avoid or limit foveal or optic disc involvement.

DESIGN

Noncomparative, retrospective, multicentric interventional case series.

PARTICIPANTS

We reviewed the medical records of 12 consecutive patients (eyes) with posterior pole (zone 1) TRC who were treated weekly or every 4 weeks (during pregnancy) with intravitreal injections of clindamycin (1.5 mg/0.1 ml) and dexamethasone (400 microg/0.1 ml).

METHODS

Ophthalmic evaluation included Early Treatment Diabetic Retinopathy Study (ETDRS) best-corrected visual acuity (BCVA); assessment of central macular thickness (CMT); resolution of inflammation by optical coherence tomography (OCT), clinical examination, and fluorescein angiography; and assessment of adverse events. Patients were followed for 24 months.

MAIN OUTCOME MEASURES

Resolution of TRC, changes in BCVA, and OCT.

RESULTS

Resolution of TRC was achieved in all cases with a mean number of injections of 3.6 (range: 2-5 injections) with a mean interval of 15.5+/-4 days. At 24 months a significant reduction in CMT by OCT was observed, from 387.6+/-70.1 microm to 185.2+/-44.7 microm (P = 0.0004). Baseline BCVA was logarithm of the minimal angle of resolution (logMAR) 1+/-0.4 (20/200), which improved to 0.5+/-0.4 (20/63) (P = 0.002) at the end of follow-up. Ten eyes (83.3%) improved > or =2 ETDRS lines of BCVA, and 2 eyes (20%) remained stable at 24 months. One patient's vision was limited because of macular scarring. No ocular or systemic adverse events were observed. No recurrences at 24 months of follow-up were observed.

CONCLUSIONS

The combination of intravitreal clindamycin and dexamethasone was associated with resolution of zone 1 TRC and functional and anatomic improvement in patients who did not tolerate, had contraindications to, or did not respond to oral medications.

[Toxoplasmosis and pregnancy]

Toxoplasmosis is the most common etiology of posterior uveitis. Toxoplasma gondii infection during pregnancy means either primary infection and risk of congenital toxoplasmosis or acute retinochoroiditis in a pregnant woman (risk of transmission, severity of injuries, therapeutics). Ingestion or manipulation of raw or undercooked meat is responsible for most contaminations (one- to two-thirds) in pregnant women. Toxoplasmosis seroprevalence is high in Europe, up to 54 % in southern European countries. Primary prevention advice is proposed to immunocompetent pregnant women who are seronegative for toxoplasmosis. The risk of transplacental transmission congenital toxoplasmosis during pregnancy is analyzed. The ocular lesions include retinochoroiditis and a number of other lesions. The departments of ophthalmology and of parasitology of Croix-Rousse University Hospital (Hospices Civils de Lyon) is currently following one of the largest cohorts of children infected with T. gondii (430 children alive in 2005). Our overall transmission rate during primary infection was 30 %. Retinochoroiditis incidence was 24 % in our prospective cohort. During follow-up, recurrences appeared in 29 % of cases. Acute toxoplasmic retinochoroiditis in pregnancy could be a risk of transplacental transmission due to potential parasitemia. Practices in cases of suspected or proved congenital infection are discussed. The antiparasitic drugs authorized during pregnancy are azithromycin and pyrimethamine. Azithromycin can be used alone but an association with pyrimethamine during the second trimester is useful in case of macular threat.

Does atovaquone prolong the disease-free interval of toxoplasmic retinochoroiditis?

BACKGROUND

To evaluate the efficacy of suppressing a recurrence of Toxoplasma retinochoroiditis after treatment with atovaquone.

METHODS

Retrospective, nonrandomized, clinical trial. Forty-one immunocompetent patients were treated for Toxoplasma retinochoroiditis with atovaquone between 1999 and 2006. The diagnosis was based on clinical signs alone. Atovaquone was given 750 mg two to three times daily together with oral steroids. Lesion location, time interval until recurrence, visual function, and adverse events were recorded.

RESULTS

Forty-two eyes of 41 patients were treated with atovaquone for Toxoplasma retinochoroiditis. Side-effects were usually mild and only one patient stopped therapy with atovaquone because of nausea. Reactivation of retinochoroiditis occurred in 18 patients (44%) during a time interval of 3-70 months.

CONCLUSIONS

The therapy of Toxoplasma retinochoroiditis with atovaquone is well tolerated. Our data suggests that therapy with atovaquone has the potential to prolong the time to recurrence of Toxoplasma retinochoroiditis. A prospective randomized comparative long-term clinical trial would be necessary to confirm our data.

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.

Toxoplasma retinochoroiditis in pregnancy: Using current evidence to inform management

Toxoplasma retinochoroiditis in pregnancy may create considerable patient anxiety and is a dilemma for the treating ophthalmologist. A case report highlighting this clinical issue is presented followed by a review of the literature. Consensus in relation to the management of toxoplasma retinochoroiditis in pregnancy is lacking and is discussed.

Trimethoprim/Sulfamethoxazole and azithromycin combination therapy for ocular toxoplasmosis

PURPOSE

To evaluate the efficacy and safety of trimethoprim/sulfamethoxazole and azithromycin combination for the treatment of ocular toxoplasmosis.

METHODS

Nineteen ocular toxoplasmosis patients treated with trimethoprim/sulfamethoxazole and azithromycin +/- corticosteroid combination were retrospectively reviewed. Demographic data, clinical findings, the time interval until resolution of inflammation, recurrences, and drug side effects were collected.

RESULTS

The mean follow-up time of the patients was 25.0 +/- 22.5 (range; 6 -66) months. Final visual acuity improved with a mean of 6 +/- 4 lines in 15 patients (78.9%). Inflammatory findings began to subside within 14.8 +/- 10.0 days. Three patients (15.8%) had recurrent attack. Only 1 patient (5.3%) had side effects from therapy.

CONCLUSIONS

Trimethoprim/sulfamethoxazole and azithromycin combination is an effective and safe treatment modality for the treatment of ocular toxoplasmosis.

[Diagnosis and treatment of ocular toxoplasmosis : a survey of German-speaking ophthalmologists]

BACKGROUND/PURPOSE

Ocular toxoplasmosis is the most frequent cause of posterior uveitis in Germany. The purpose of this survey was to evaluate current strategies in the management of ocular toxoplasmosis by uveitis specialists in Germany.

METHODS

An itemized questionnaire including clinical case reports with authentic photographs was distributed to physician members (n=40) of the German Uveitis Society. In addition, members were categorized regarding their clinical background, professional affiliation and experience with ocular toxoplasmosis.

RESULTS

The completed questionnaire was returned by 72% (29/40) of the members. According to the answers, the majority (70%) of responders base their diagnosis of ocular toxoplasmosis on clinical examination and serological findings. Although a positive IgM titre or increasing IgG titres support the diagnosis only in cases of recently acquired disease, these are reported to support the diagnosis by 58 and 41%, respectively. Invasive procedures such as aqueous humour analysis are performed by 59% of colleagues to establish the diagnosis in selected patients. A total of six antimicrobial agents were reported for treatment in different regimens for typical clinical conditions in patients with recurrent toxoplasmic retinochoroiditis. The combination of pyrimethamine and sulfadiazine is the most commonly used (48%), followed by clindamycin (38%).

CONCLUSIONS

Our survey indicates the lack of a "gold standard" for diagnosis and medical treatment in ocular toxoplasmosis. Further efforts have to be undertaken towards a better distribution of available information and to determine strategies for providing standards of continuously updated diagnostic and therapeutic recommendations for routine clinical practice.

[Recurrent toxoplasmic retinochoroiditis after clindamycin treatment]

PURPOSE

To evaluate the efficacy and safety of subconjunctival injections of clindamycin associated with oral corticotherapy in the treatment of toxoplasmic retinochoroiditis (TRC) and its effect on recurrence.

PATIENTS AND METHODS

This study investigated 21 patients (10 males and 11 females) who presented to an ophthalmological department from 1995 to 2000, aged 14-55 years (mean, 28 years), with unilateral TRC. They were treated with subconjunctival injections of clindamycin and systemic corticotherapy at a dose of 1 mg/kg/day. Clinical follow-up consisted of assessment of visual acuity and biomicroscopic fundus examination, completed by retinal angiography if necessary.

RESULTS

We observed clinical improvement in 68.75% of patients within 4 days and in all patients healing of the chorioretinal area within 1.6 months. During the follow-up period ranging from 6 to 52 months (mean, 22 months), there have been two recurrences (9%) over the first 18 months. Tolerance of the injections was good. Serious side effects were noted in two patients: one case of conjunctival necrosis and one case of corneal and conjunctival erosion.

CONCLUSION

In treating ocular toxoplasmosis, clindamycin appears to be a safe and effective substitute for the classic protocol (pyrimethamine-sulfadiazine, pyrimethamine-azithromycin), for which a 50% recurrence rate has been reported. It provides relatively good protection against recurrence and warrants testing in further controlled studies.

Prospective Randomized Trial of Trimethoprim/Sulfamethoxazole versus Pyrimethamine and Sulfadiazine in the Treatment of Ocular Toxoplasmosis

OBJECTIVE

To compare the efficacy of the classic treatment of ocular toxoplasmosis (pyrimethamine, sulfadiazine, and prednisolone) with a regimen consisting of trimethoprim/sulfamethoxazole (co-trimoxazole) plus prednisolone.

DESIGN

Prospective randomized single-blind clinical trial.

PARTICIPANTS

Fifty-nine patients with active ocular toxoplasmosis were randomly assigned to 2 treatment groups: 29 were treated with pyrimethamine/sulfadiazine, and 30 patients received trimethoprim/sulfamethoxazole.

INTERVENTION

Treatment consisted of 6 weeks' treatment with antibiotics plus steroids. Antitoxoplasmosis antibodies (immunoglobulin M [IgM] and IgG) were measured using an enzyme-linked immunosorbent assay.

MAIN OUTCOME MEASURES

Changes in retinochoroidal lesion size after 6 weeks' treatment, visual acuity (VA) before and after intervention, adverse drug reactions during follow-up, and rate of recurrence.

RESULTS

Active toxoplasmosis retinochoroiditis resolved in all patients over 6 weeks' treatment, with no significant difference in mean reduction of retinochoroidal lesion size between the 2 treatment groups (61% reduction in the classic treatment group and 59% in the trimethoprim/sulfamethoxazole group, P = 0.75). Similarly, no significant difference was found in VA after treatment between the 2 groups (mean VAs after treatment were 0.12 logarithm of the minimum angle of resolution [logMAR] [20/25] in the classic treatment group and 0.09 logMAR [20/25] in the trimethoprim/sulfamethoxazole group, P = 0.56). Adverse effects were similar in both groups, with one patient in each suffering from any significant drug side effects. The overall recurrence rate after 24 months' follow-up was 10.16%, with no significant difference between the treatment groups (P = 0.64).

CONCLUSIONS

Drug efficacies in terms of reduction in retinal lesion size and improvement in VA were similar in a regimen of trimethoprim/sulfamethoxazole and the classic treatment of ocular toxoplasmosis with pyrimethamine and sulfadiazine. Therapy with trimethoprim/sulfamethoxazole seems to be an acceptable alternative for the treatment of ocular toxoplasmosis.

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.

An update on current practices in the management of ocular toxoplasmosis

PURPOSE

To update information that was published by the AMERICAN JOURNAL OF OPHTHALMOLOGY in 1991 about treatment practices for ocular toxoplasmosis by uveitis specialists.

DESIGN

Physician survey.

METHODS

A written questionnaire was distributed to all physician-members (n = 147) of the American Uveitis Society. The questionnaire was modeled after a similar device used to survey uveitis specialists in 1991. Information contained on 96 returned questionnaires was tabulated.

RESULTS

Among 79 respondents who evaluate and manage patients with ocular toxoplasmosis, 15% treat all cases regardless of clinical findings (in contrast to 6% in 1991). The major indications for treatment among other respondents were severe inflammatory responses and proximity of retinal lesions to the fovea and optic disk. The majority of clinical factors considered in five categories (vision, lesion location, lesion size, lesion characteristics, and vitreous inflammatory reaction) were identified to be relative or absolute indications for treatment by a greater proportion of respondents in the current survey than in the 1991 survey. A total of nine drugs (or commercially available combinations) were used in 24 different regimens as treatments of choice for typical cases of recurrent toxoplasmic retinochoroiditis, with the combination of pyrimethamine, sulfadiazine, and prednisone being the most commonly used regimen (29% of respondents).

CONCLUSIONS

Uveitis specialists appear to be more likely to treat patients with ocular toxoplasmosis in 2001 than in 1991. Although the majority of survey respondents adhere to a traditional approach to the management of toxoplasmic retinochoroiditis (a discrete course of systemic drug treatment during active disease using multiple antiparasitic drugs with or without corticosteroids), there is still no consensus regarding the choice of antiparasitic agents for treatment regimens. Survey results provide useful information for treating physicians and for clinical investigators interested in therapy.

A prospective, randomized trial of pyrimethamine and azithromycin vs pyrimethamine and sulfadiazine for the treatment of ocular toxoplasmosis

OBJECTIVE

To compare the effects of two treatment regimens, one of which included azithromycin, for the treatment of sight-threatening (near optic disk or fovea) ocular toxoplasmosis.

DESIGN

Prospective, randomized open-labeled multicenter study, masked in part with regard to evaluation.

METHODS

PARTICIPANTS TOTAL ENROLLMENT: 46 patients with sight-threatening ocular toxoplasmosis; pyrimethamine and azithromycin group: 24 patients; pyrimethamine and sulfadiazine group: 22 patients.

INTERVENTION

Patients were randomized into two treatment regimens. Group 1 was treated with pyrimethamine and azithromycin complemented with folinic acid and the addition of prednisone from day 3. Group 2 was treated with pyrimethamine and sulfadiazine complemented with folinic acid and the addition of prednisone from day 3. Patients used study medications daily for 4 weeks. Ocular and laboratory examinations were performed at least weekly during the observation period. The study was masked in part with regard to evaluation.

MAIN OUTCOME MEASURES

An assessment was made of the time to resolution of the intraocular inflammatory activity, the size of the retinochoroidal lesion, and visual acuity before and after the treatment as well as all adverse effects of treatments.

RESULTS

Adverse effects were more frequent in the pyrimethamine/sulfadiazine group (P <.04), and three patients in this group had to discontinue treatment. The time to resolution of inflammatory activity, decrease in size of retinochoroidal lesions, and optimal visual acuity did not differ between the two treatment groups. The number of patients who developed recurrences during the first year after treatment was similar for both groups.

CONCLUSIONS

The efficacy of the multidrug regimen with pyrimethamine and azithromycin was similar to the standard treatment with pyrimethamine and sulfadiazine. However, the frequency and severity of adverse effects was significantly lower with a regimen containing pyrimethamine and azithromycin. Multidrug therapy with the combination of pyrimethamine and azithromycin appears to be an acceptable alternative for treatment of sight-threatening ocular toxoplasmosis.

Ocular toxoplasmosis after the fifth decade

PURPOSE

To describe the clinical features in patients presenting with ocular toxoplasmosis after the fifth decade and to analyze laboratory findings in comparison to uveitis history and clinical data.

DESIGN

Prospective consecutive observational case series.

METHODS

A prospective clinical analysis of 27 consecutive patients older than 50 years of age with primary or recurrent ocular toxoplasmosis was performed during a period of 8 years. These cases account for 12% of all ocular toxoplasmosis cases irrespective of age indexed in our institution during the same period. Paired serum and aqueous humor samples were tested for anti-Toxoplasma gondii IgG, IgM, and IgA antibodies. The presence of T. gondii DNA in aqueous humor was determined by polymerase chain reaction followed by DNA hydridization method.

RESULTS

Although similar in age, two groups were distinguished clinically: 12 patients (44%) presented with usual forms of retinochoroiditis (mean +/- SD, 1.6 +/- 0.5 disk areas [DA] in size); 15 patients (56%) presented with atypical lesions, greater than 3 DA in size (mean +/- SD, 5.0 +/- 2.0 DA). The second group showed a higher rate of complications (P =.028) and a poorer visual outcome (P =.015). Twenty-four patients (89%) had intraocular IgG production, 17 (63%) had intraocular IgA production, 3 (11%) had intraocular IgM production, and 12 (44%) had a positive T. gondii DNA detection.

CONCLUSIONS

After the fifth decade, ocular toxoplasmosis remains an important cause of posterior uveitis. The combination of antibody detection by immunocapture tests with T. gondii DNA detection, both in aqueous humor, allowed the diagnosis of toxoplasmic infection in the atypical cases with large ocular lesions.