Intravitreal clindamycin plus dexamethasone versus classic oral therapy in toxoplasmic retinochoroiditis: a prospective randomized clinical trial

Clinical Insights: Antimicrobial Therapy for Infectious Uveitis

Infectious uveitis is a major global cause of vision impairment. Despite the eye's immune privilege, afforded by the blood-ocular barrier that restricts microbial entry, several pathogens such as bacteria, viruses, fungi, and parasites can still infiltrate and cause ocular infections and complications. Clinicians often encounter significant challenges in treating infectious uveitis due to limited or ineffective treatment options. Modern molecular techniques and imaging can aid in diagnosing and assessing intraocular infections. Various antimicrobial therapies exist, spanning topical and systemic treatments, but these are constrained by issues like drug concentration, penetration, effective duration, toxicity, and side effects. Treatment approaches also differ based on the infection's etiology. This review provides recent updates on antimicrobial therapies from a clinical perspective, covering topical, systemic, and regional treatments for infectious uveitis.

Considerations in the management of ocular toxoplasmosis in pregnancy: a review of literature

Ocular toxoplasmosis is the most common cause of infectious posterior uveitis. Available literature is still conflicting regarding the incidence of recurrence during pregnancy as various calculations were employed in the different published studies. Although earlier reports have suggested a difference in presentation and an increase in severity during pregnancy, newer studies appear to show otherwise. Further diagnostic testing, including serologic and intraocular fluid sampling, may be indicated to increase the diagnostic accuracy in this special population of patients. The management of ocular toxoplasmosis during pregnancy is challenging as the foetus is additionally considered in the choice of treatment. Traditionally preferred anti-toxoplasmosis regimens containing antifolate drugs, such as pyrimethamine and trimethoprim-sulfamethoxazole, cannot be used routinely in pregnant patients, especially during the first trimester. This review includes literature on alternative treatments for ocular toxoplasmosis during pregnancy, including spiramycin and intravitreal treatment options.

The Host-Pathogen Interplay: A Tale of Two Stories within the Cornea and Posterior Segment

Ocular infectious diseases are an important cause of potentially preventable vision loss and blindness. In the following manuscript, we will review ocular immunology and the pathogenesis of herpesviruses and Pseudomonas aeruginosa infections of the cornea and posterior segment. We will highlight areas of future research and what is currently known to promote bench-to-bedside discoveries to improve clinical outcomes of these debilitating ocular diseases.

Clinical outcomes of intravitreal treatment for ocular toxoplasmosis: systematic review and meta-analysis

BACKGROUND

Ocular toxoplasmosis is the leading cause of infectious posterior uveitis worldwide, accounting for 30-50% of all cases in immunocompetent patients. Conventional treatment is associated with adverse effects and does not prevent recurrence. Intravitreal drug administration can improve disease outcomes and reduce side effects. Herein, we conducted a systematic review and meta-analysis on the efficacy of intravitreal injections for treating ocular toxoplasmosis.

METHODS

The systematic search was conducted using PubMed, SciELO, and Google Scholar with the descriptors "ocular toxoplasmosis" AND "intravitreal". We analyzed studies that met the inclusion criteria, i.e., experimental cases in patients treated intravitreally for ocular toxoplasmosis. Considering the systematic review, we focused on the number of intravitreal injections, the therapeutic drug class, and the presence of preexisting conditions. To assess the efficacy of intravitreal injections, a meta-analysis was performed using visual acuity, side effects, disease recurrence, and inflammatory responses as variables.

RESULTS

Intravitreal injection-induced side effects were rarely observed (0.49% [0.00, 1.51%] ). The use of antiparasitic and anti-inflammatory drugs afforded improved visual acuity (99.81% [98.60, 100.00%]) and marked effectiveness in treating ocular toxoplasmosis.

CONCLUSIONS

Intravitreal injections may facilitate the successful treatment of ocular toxoplasmosis. However, clinicians should carefully evaluate the presence of preexisting conditions for ocular toxoplasmosis or previous diseases, as these can impact the decision to administer intravitreal injections.

Risk factors for recurrences and visual impairment in patients with ocular toxoplasmosis: A systematic review and meta-analysis

BACKGROUND

Ocular toxoplasmosis (OT) is caused by the parasite Toxoplasma gondii. OT is the leading cause of posterior uveitis globally; it is a recurrent disease that may result in visual impairment and blindness. This systematic review and meta-analysis aim to summarize and evaluate the risk factors for recurrences, visual impairment, and blindness described in the literature worldwide.

METHODS AND FINDINGS

We performed a systematic literature search in PubMed, Embase, VHL, Cochrane Library, Scopus, and DANS EASY Archive. All studies reporting patients with clinically and serologically confirmed OT presenting any clinical or paraclinical factor influencing recurrences, visual impairment, and blindness were included. Studies presenting secondary data, case reports, and case series were excluded. An initial selection was made by title and abstract, and then the studies were reviewed by full text where the eligible studies were selected. Then, the risk of bias was assessed through validated tools. Data were extracted using a validated extraction format. Qualitative synthesis and quantitative analysis were done. This study was registered on PROSPERO (CRD42022327836).

RESULTS

Seventy two studies met the inclusion criteria. Fifty-three were summarized in the qualitative synthesis in three sections: clinical and environmental factors, parasite and host factors, and treatment-related factors. Of the 72 articles, 39 were included in the meta-analysis, of which 14 were conducted in South America, 13 in Europe, four in Asia, three multinational, two in North America and Central America, respectively, and only one in Africa. A total of 4,200 patients with OT were analyzed, mean age ranged from 7.3 to 65.1 year of age, with similar distribution by sex. The frequency of recurrences in patients with OT was 49% (95% CI 40%-58%), being more frequent in the South American population than in Europeans. Additionally, visual impairment was presented in 35% (95% CI 25%-48%) and blindness in 20% (95% CI 13%-30%) of eyes, with a similar predominance in South Americans than in Europeans. On the other hand, having lesions near the macula or adjacent to the optic nerve had an OR of 4.83 (95% CI; 2.72-8.59) for blindness, similar to having more than one recurrence that had an OR of 3.18 (95% CI; 1.59-6.38). Finally, the prophylactic therapy with Trimethoprim/Sulfamethoxazole versus the placebo showed a protective factor of 83% during the first year and 87% in the second year after treatment.

CONCLUSION

Our Systematic Review showed that clinical factors such as being older than 40 years, patients with de novo OT lesions or with less than one year after the first episode, macular area involvement, lesions greater than 1 disc diameter, congenital toxoplasmosis, and bilateral compromise had more risk of recurrences. Also, environmental and parasite factors such as precipitations, geographical region where the infection is acquired, and more virulent strains confer greater risk of recurrences. Therefore, patients with the above mentioned clinical, environmental, and parasite factors could benefit from using prophylactic therapy.

In vitro and in vivo anti−Toxoplasma activities of HDAC inhibitor Panobinostat on experimental acute ocular toxoplasmosis

Ocular toxoplasmosis (OT) is retinochoroiditis caused by Toxoplasma gondii infection, which poses a huge threat to vision. However, most traditional oral drugs for this disease have multiple side effects and have difficulty crossing the blood-retinal barrier, so the new alternative strategy is required to be developed urgently. Histone deacetylases (HDAC) inhibitors, initially applied to cancer, have attracted considerable attention as potential anti-Toxoplasma gondii drugs. Here, the efficacy of a novel HDAC inhibitor, Panobinostat (LBH589), against T. gondii has been investigated. In vitro, LBH589 inhibited the proliferation and activity of T. gondii in a dose-dependent manner with low toxicity to retinal pigment epithelial (RPE) cells. In vivo, optical coherence tomography (OCT) examination and histopathological studies showed that the inflammatory cell infiltration and the damage to retinal architecture were drastically reduced in C57BL/6 mice upon treatment with intravitreal injection of LBH589. Furthermore, we have found the mRNA expression levels of inflammatory cytokines were significantly decreased in LBH589–treated group. Collectively, our study demonstrates that LBH589 holds great promise as a preclinical candidate for control and cure of ocular toxoplasmosis.

Ocular Toxoplasmosis: No Stranger to the Masquerade Ball

Purpose:

This article illustrates multiple atypical manifestations of ocular toxoplasmosis masquerading as acute retinal necrosis and vitreoretinal lymphoma.

Methods:

Two case presentations are discussed, and the body of pertinent literature is reviewed and discussed.

Results:

In these cases, an extensive workup and attention to history lead to the correct diagnosis and management.

Conclusions:

Aggressive cases of ocular toxoplasmosis may present in a variety of phenotypes that may mimic other vision- and potentially life-threatening conditions, particularly in a milieu of inadequate endogenous and exogenous antimicrobial defenses.

A Comprehensive Update on Retinal Vasculitis: Etiologies, Manifestations and Treatments

Retinal vasculitis is characterized by inflammatory involvement of retinal arterioles, venules and/or capillaries and can be associated with a myriad of systemic and ophthalmic diseases. In this review, we have comprehensively discussed the etiologies, clinical manifestations, and presentations of retinal vasculitis. We have also included newer advances in imaging in retinal vasculitis such as OCTA and widefield imaging.

Ocular toxoplasmosis, an overview focusing on clinical aspects

Toxoplasma gondii is a widespread protozoan parasite infecting approximately one third of the world population. After proliferation of tachyzoites during the acute stage, the parasite forms tissue cysts in various anatomical sites and establishes chronic infection. Nowadays the nature of the interplay between the protozoan and its human host remains elusive. This is clearly evident in ocular toxoplasmosis, in which the parasite establishes an ambivalent relationship with the eye, manipulating the immune response and inducing variable initial lesions and further relapses. This review will focus on epidemiology and environmental, parasite and host related risk factors, clinical manifestations and laboratory findings, treatment and prophylaxis approaches in ocular toxoplasmosis. An image collection of patients referred to the Unit of Ophthalmology of Pisa's Hospital will be presented, too.

Macular Infarction following Intravitreal Clindamycin Injection : A Case Report

Purpose

To report a case of Toxoplasma retinochoroiditis that was complicated by macular infarction following intravitreal clindamycin injection.

Methods

A 32-year-old otherwise healthy woman with the diagnosis of reactivation of Toxoplasma retinochoroiditis in her right eye, underwent intravitreal clindamycin injection. Shortly after injection, the visual acuity deteriorated, and the fundus examination revealed an extensive area of macular necrosis accompanied by vascular occlusion.

Results

The patient was observed. Unfortunately, the condition did not improve over time and resulted in a large area of retinal atrophy.

Conclusion

Macular infarction should be considered a rare but disastrous complication that can result in severe, irreversible visual loss.

Ocular toxoplasmosis in immunocompetent adults: current cost-effectiveness of four treatment regimens in Colombia

BACKGROUND

Ocular toxoplasmosis is an infection caused by Toxoplasma gondii. In South America, the clinical course of ocular toxoplasmosis is more severe than in Europe and North America because virulent strains of the parasite are present. Ocular toxoplasmosis is the leading cause of posterior uveitis and retinochoroiditis in Colombia, requiring timely and appropriate treatment. However, there is no standardized therapy protocol based on economic studies for the country.

PURPOSE

To compare the cost-effectiveness of four first-line treatment regimens for active ocular toxoplasmosis in immunocompetent adults in Colombia, using the number of averted therapeutic failures as the outcome.

METHODS

We performed an economic and cost-effectiveness analysis to compare four first-line treatment regimens for ocular toxoplasmosis from the perspective of a third-party payer (Colombian General System of Social Security in Health). A decision analysis tree was used over a 24-week time horizon, considering only direct costs. Additionally, we performed a discrete sensitivity analysis and a probabilistic sensitivity analysis with 10,000 iterations in the Monte Carlo simulation.

RESULTS

For the base case, trimethoprim/sulfamethoxazole showed 86% effectiveness at a cost of <57 United States Dollars, resulting in the most cost-effective first-line alternative. When performing the probabilistic sensitivity analysis and maintaining the willingness to pay 466.00 United States Dollars, the trimethoprim/sulfamethoxazole regimen remained the most cost-effective alternative.

CONCLUSION

Ocular toxoplasmosis is a public health issue in Latin America. Despite severe visual consequences for affected patients, there are no standardized treatment guidelines in countries such as Colombia. Our evidence supports the use of trimethoprim/sulfamethoxazole as first-line treatment in Colombia because of its availability and optimal cost-effectiveness performance; it reduces recurrences and complications, while averting therapeutic failure. Furthermore, our evidence can be generalized to other Latin American countries with similar frequencies and severities of Toxoplasma gondii ocular infection and health systems similar to the Colombian system.

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.

Safety and efficacy of different antibiotic regimens in patients with ocular toxoplasmosis: systematic review and meta-analysis

BACKGROUND

Ocular toxoplasmosis (OT) is the most common cause of posterior uveitis, which leads to visual impairment in a large proportion of patients. Antibiotics and corticosteroids lower the risk of permanent visual loss by controlling infection and inflammation. However, there remains disagreement regarding optimal antibiotic therapy for OT. Therefore, this systematic review and meta-analysis were performed to determine the effects and safety of existing antibiotic treatment regimens for OT.

METHODS

MEDLINE, EMBASE, The Cochrane Central Register of Controlled Trials, LILACS, WHO International Clinical Trials Registry Platform portal, ClinicalTrials.gov, and Gray Literature in Europe ("OpenGrey") were searched for relevant studies; manual searches of reference lists were performed for studies identified by other methods. All published and unpublished randomized controlled trials that compared antibiotic schemes known to be effective in OT at any dosage, duration, and administration route were included. Studies comparing antibiotics with placebo were excluded. This review followed standard methodological procedures recommended by the Cochrane group.

RESULTS

Ten studies were included in the narrative summary, of which four were included for quantitative synthesis (meta-analysis). Interventions were organized into three groups: intravitreal clindamycin versus pyrimethamine + sulfadiazine, trimethoprim + sulfamethoxazole versus other antibiotics, and other interventions. The first comparison favored intravitreal clindamycin (Mean difference (MD) = 0.10 logMAR; 95% confidence interval = 0.01 to 0.22). However, this finding lacks clinical relevance. Other outcomes showed no statistically significant differences between the treatment groups. In general, the risk of performance bias was high in evaluated studies, and the quality of the evidence found was low to very low.

CONCLUSIONS

No antibiotic scheme was superior to others, and the selection of a treatment regimen depends on multiple factors; therefore, treatment should be chosen based on safety, sulfa allergies, and availability.

Treatment Strategy in Human Ocular Toxoplasmosis: Why Antibiotics Have Failed

Background: There is currently no clear evidence of the effectiveness of antibiotic therapy in acute ocular toxoplasmosis (OT), but its effect as a secondary prophylaxis is undisputed. The majority of uveitis specialists advocate treatment. This meta-analytic review aims to critically analyze determinants of treatment success and to update current treatment strategies for OT in order to explain this discrepancy. Methods: A systematic literature search was performed in NCBI/PubMed, Clinical Trials, Google Scholar and ScienceDirect to retrieve pro- and retrospective studies using the key terms “ocular toxoplasmosis” or “retinochoroiditis” and “immunocompetent” and “treatment” or “therapy” and “human.” Of these, larger case series and prospective clinical studies and cross references identified from meta-analyses were selected by a manual search, and primary and secondary outcome parameters were extracted. Results: Ten case series and clinical trials reported success parameters for treatment outcomes, and four additional for recurrence prophylaxis. Five treatment studies were randomized clinical trials, three comparative and two noncomparative case series. Though several outcome parameters were reported, five of them defined time to healing, four visual gain and one lesion size as primary and secondary outcome parameters, recurrence rate as a secondary outcome parameter was reported once. No conclusive evidence was found for an antibiotic treatment effect. Four prophylaxis studies addressed the prevention of recurrences after treatment. The primary outcome in all studies was the effect of treatment and prophylaxis on recurrences, and all four found a significant effect on the risk of and time to recurrences. Conclusions: Antibiotic treatment of OT aims at controlling parasite proliferation. The absence of an effect on visual acuity and time to healing is thus not surprising. The fact that time to and number of recurrences respond to recurrence of prophylaxis proves the antibiotic effect on parasite activity.

<p>Intravitreal Clindamycin as First-Line Therapy for Toxoplasmic Retinochoroiditis: A Case Series</p>

Purpose

Materials and Methods

Results

Conclusion

Human immunodeficiency virus and intraocular inflammation in the era of highly active anti retroviral therapy - An update

Intraocular inflammation in patients with human immunodeficiency virus (HIV) infection is commonly due to infectious uveitis. Ocular lesions due to opportunistic infections (OI) are the most common and have been described extensively in the pre highly active antiretroviral therapy (HAART) era. Many eye lesions were classified as acquired immunodeficiency syndrome (AIDS) defining illnesses. HAART-associated improvement in immunity of the individual has changed the pattern of incidence of these hitherto reported known lesions leading to a marked reduction in the occurrence of ocular OI. Newer ocular lesions and newer ocular manifestations of known agents have been noted. Immune recovery uveitis (IRU), the new menace, which occurs as part of immune recovery inflammatory syndrome (IRIS) in the eye, can present with significant ocular inflammation and can pose a diagnostic and therapeutic challenge. Balancing the treatment of inflammation with the risk of reactivation of OI is a task by itself. Ocular involvement in the HAART era can be due to the adverse effects of some systemic drugs used in the management of HIV/AIDS. Drug-associated retinal toxicity and other ocular side effects are being increasingly reported. In this review, we discuss the ocular manifestations in HIV patients and its varied presentations following the introduction of HAART, drug-associated lesions, and the current treatment guidelines.

Approach to ocular toxoplasmosis including pregnant women

PURPOSE OF REVIEW

To discuss available information on the effectiveness of anti-toxoplasma therapy for ocular toxoplasmosis and to provide clinicians with a practical approach to the disease.

RECENT FINDINGS

Only eleven randomized studies were identified. In the three studies for acute retinitis, there was a clear trend in favor of treatment. In the two studies for the prevention of recurrences, trimethoprim-sulfamethoxazole prophylaxis was superior to placebo. In the six studies comparing different regimens, there was no statistically significant difference between the regimens. In the setting of acute posterior uveitis suspected to be caused by toxoplasma, serological testing should always be obtained, and anti-toxoplasma drug treatment, and corticosteroids should be instituted for at least 6 weeks. Toxoplasmic chorioretinitis during pregnancy represents a particular challenge.

SUMMARY

Treatment with at least two drugs and corticosteroids should be offered to patients with active toxoplasmic chorioretinitis. Pregnant women with confirmed acute infection and concomitant acute retinitis should be treated for the ocular lesion(s) and to prevent vertical transmission. Pregnant women with chronic Toxoplasma infection acquired prior to gestation and concomitant retinitis by reactivation should be treated for the retinitis and monitored for vertical transmission.

Disease of the Year 2019: Ocular Toxoplasmosis in HIV-infected Patients

Ocular toxoplasmosis (OT) may be an initial manifestation of acquired immunodeficiency syndrome (AIDS) in human immunodeficiency virus (HIV)-infected patients. OT has different clinical manifestations and can mimic other intraocular infections. Clinical findings may show single or multifocal retinochoroidal lesions or panuveitis. Atypical presentations are associated with extensive uni- or bilateral areas of retinal necrosis. OT lesions not associated with preexisting retinochoroidal scars are usually due to acquired rather than congenital infection. When CD4+ T cell counts are <100 c/uL, vitritis is frequently mild. Isolated anterior uveitis has been reported in single cases. Positive immunoglobulin M (IgM) antibodies are rare but their presence can support the diagnosis. As atypical presentations of OT are common, anterior chamber puncture for multiplex polymerase chain reaction amplification of infectious DNA should be considered, as early diagnosis and treatment can prevent massive tissue destruction and preserve vision. This review provides an overview of OT in HIV-infected patients.

Intravitreal clindamycin as a therapeutic alternative in severe ocular toxoplasmosis

Ocular toxoplasmosis is a disease than have severe consequences on the eyesight. The aim of this study article is to present a bilateral ocular toxoplasmosis in a sulfamide allergic patient with unilateral activation and her favourable progression with intravitreal Clindamycin and oral steroids treatment. Weekly intravitreal Clindamycin treatment is shown to be a suitable therapeutic alternative in cases of severe ocular toxoplasmosis and/or in patients with a contraindication to classical treatment. Intravitreal Clindamycin treatment is a safe alternative with favourable clinical results.

Ocular Toxoplasmosis in a Tertiary Referral Center in Sydney Australia-Clinical Features, Treatment, and Prognosis

PURPOSE

The aim of this study was to provide a retrospective analysis of the presentation, demographics, and treatment regimens for ocular toxoplasmosis at a large tertiary referral uveitis center.

DESIGN

Retrospective cohort study.

PARTICIPANTS

A total of 48 patients with ocular toxoplasmosis who presented to Sydney Eye Hospital participated in this study.

METHODS

This is a retrospective review of patient files who presented to Sydney Eye Hospital between 2007 and 2016 with clinical features consistent with ocular toxoplasmosis. Baseline risk factors and treatment details were recorded and analyzed. Main outcome measures were visual acuity and relapse rate compared with other studies in ocular toxoplasmosis.

RESULTS

The median age was 35.5 (interquartile range 21-50) with 30 (60%) patients having no previous symptomatic episodes or evidence of chorioretinal scarring. Visual acuity at presentation was 0.51 or 6/19 (SE 0.096) and at follow-up 0.31 or 6/12 (SE 0.094). Nine patients experienced a recurrence during the period of observation with median time to recurrence 2.2 years (SE 0.45) and the relapse rate was 0.09/person-years. Location of lesion was predominantly within the vascular arcades (n = 44) with macular involvement in 9 patients. Most patients received clindamycin therapy (n = 34) with pyrimethamine and sulfadiazine was used for those with macula involvement.

CONCLUSIONS

Patients with ocular toxoplasmosis had fewer recurrences compared with other published series and had better visual recovery. The majority of patients received clindamycin and oral prednisolone which were well tolerated with pyrimethazine and sulfadiazine reserved for those with macula-involving disease.

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.

Current treatment of ocular toxoplasmosis in immunocompetent patients: a network meta-analysis

Ocular toxoplasmosis (OT) is the most frequent form of infectious posterior uveitis caused by the protozoan parasite Toxoplasma gondii. To evaluate the available evidence in peer-reviewed publications about the most effective therapy for OT in immunocompetent patients, herein a systematic literature search was conducted using Embase, PubMed, Google Scholar, and the Cochrane Central Register of Controlled Trials (CENTRAL) database from January 1987 to October 2017, with search terms "OT", "retinochoroiditis", "treatment", and "immunocompetent"; search filters "controlled clinical trial", "randomized clinical trial", and "clinical trial". The included studies were performed to evaluate the various treatment modalities of OT. Different treatment regimens were compared with regard to the improvement of visual acuity, the resolution of vitreous inflammation, recurrence, and side-effects. We independently extracted data and assessed eligibility and risk of bias using the preferred reporting items for systematic reviews and meta-analysis, and resolved any disagreement through discussion. A Bayesian network meta-analysis model was used to evaluate the interesting outcomes of all the interventions. Total 10 trials of treatments for OT were found to meet the inclusion criteria. Six trials of treatments including clindamycin, azithromycin, and trimethoprim-sulfamethoxazole (TMP-SMX) were compared with conventional therapy (the combination of pyrimethamine, sulfadiazine, and corticosteroids) for evaluation of the effect on visual acuity, vitreous inflammation, recurrence of OT, and side-effects. Two trials were compared TMP-SMX with placebo. One trial was compared azithromycin with TMP-SMX. And another trial was compared among treatments with clindamycin, P-S, TMP-SMX, and placebo. Based on our network meta-analysis, therapy with TMP-SMX seems to be an alternative treatment of OT in immunocompetent patients.

Adverse Event Profile of Pyrimethamine-Based Therapy in Toxoplasmosis: A Systematic Review

Introduction

Approximately a third of the population worldwide is chronically infected with Toxoplasma gondii. Pyrimethamine-based regimens are recommended for the treatment of toxoplasmosis.

Objective

The aim was to evaluate the safety profile of pyrimethamine-based treatment for the three main Toxoplasma manifestations: toxoplasmic encephalitis (TE), ocular toxoplasmosis, and congenital toxoplasmosis.

Methods

PubMed, Cochrane Library, and Google Scholar databases were searched through August 1, 2016. Randomized, observational, prospective/retrospective, and cohort studies were eligible. Thirty-one studies were included with a total of 2975 patients. Of these, 13 were in congenital toxoplasmosis (n = 929), 11 in ocular toxoplasmosis (n = 1284), and seven in TE (n = 687). Across manifestations, adverse event (AE)-related treatment discontinuation and/or change in therapy involved ≤37% of patients and occurred in >55% of studies: 100% for ocular toxoplasmosis, 57.1% for TE, and 61.5% for congenital toxoplasmosis. The most commonly observed AEs were bone marrow suppression, dermatologic, and gastrointestinal (GI). The prevalence of bone marrow suppression-related AEs was ≤50% in congenital toxoplasmosis, ≤42.7% in TE, and ≤9.0% in ocular toxoplasmosis. The frequency of GI and dermatologic AEs were ≤100 and ≤11.1%, respectively, for ocular toxoplasmosis, ≤10.7 and ≤17.9% for TE, and ≤10.8 and ≤2.1% for congenital toxoplasmosis. Steven–Johnson syndrome was reported in two patients with ocular toxoplasmosis and one with TE.

Conclusion

The AE profile associated with pyrimethamine-based treatments differed by each manifestation of toxoplasmosis and within a given manifestation. Hematologic AEs occurred across all manifestations indicating the importance of monitoring the blood of patients administered pyrimethamine-based regimens.

Safety of intravitreal clindamycin in albino rabbit eyes

PURPOSE

To study the potential toxic effects of intravitreal clindamycin on the retina of albino rabbits, by assessing functional and morphological retinal changes.

METHODS

Eight albino rabbits were included in the study. In each rabbit, 1 mg/0.1 ml clindamycin was injected into the vitreous of the right (experimental) eye, and 0.1 ml saline was injected into the vitreous of the left (control) eye. The electroretinogram (ERG) was recorded before injection, 3 days, 1, 2, and 4 weeks post-injection. The visual evoked potential (VEP) was recorded 4 weeks post-injection. Clinical examination was conducted at all time points. The eyes were enucleated at the termination of the follow-up period in order to prepare the retinas for histology in order to assess retinal structure.

RESULTS

ERG and VEP responses that were recorded from the experimental eye at different times following intravitreal clindamycin injection were very similar to the corresponding responses that were recorded from the control eyes. Clinical examination was normal in all eyes, and no histological damage was observed.

CONCLUSIONS

Intravitreal injection of 1 mg clindamycin does not cause functional or morphological signs of retinal toxicity in albino rabbits, during a period of 4 weeks post-injection. These findings support the clinical use of 1 mg intravitreal clindamycin.

Infectious uveitis: An enigma

Infectious uveitis accounts for majority of the cases of uveitis in developing countries. It also encompasses an array of various microorganisms and their clinical presentations. Some of these infectious uveitic entities are familiar, while others are newly emerging in the global ophthalmic world. Many of these entities are also a major cause of morbidity and mortality, and appropriate, timely management is required to save not the eye, but life of the patient. This review highlights the ocular manifestations of various infectious uveitic entities, relevant to the ophthalmologist.

Corticosteroids as adjuvant therapy for ocular toxoplasmosis

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 METHODS

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.

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.

Current Practices in Ocular Toxoplasmosis: A Survey of Brazilian Uveitis Specialists

PURPOSE

To describe treatment practices for ocular toxoplasmosis among members of the Brazilian Uveitis Society.

METHODS

An online questionnaire sent to specialists, between October 2014 and March 2015.

RESULTS

Most respondents (67.9%) treat all active cases. Most specialists consider visual acuity <20/200 (88.2%), severe vitreous inflammation (94.1%), and ocular disease during acquired infection (88.2%) as absolute indications for treatment. Systemic steroids are associated with anti-toxoplasmic therapy in most cases by 50.9% of the respondents. For immunocompetent individuals, 57.4% of the respondents chose trimethoprim/sulfamethoxazole. Classical therapy (sulfadiazine/pyrimethamine) is preferred most for patients with central lesions (70.4%), immunosuppression (68.4%), acquired infection (70.4%), and atypical forms (74.1%). For patients with frequent relapses, 84.9% of the respondents preferred antibiotic prophylaxis.

CONCLUSIONS

Treatment patterns of ocular toxoplasmosis are not uniform among Brazilian specialists. Most specialists treat all cases of active retinochoroiditis. Typical cases are more frequently treated with trimethoprim/sulfamethoxazole. However, classical therapy is the regimen of choice when lesions are considered more severe.

Antibiotics versus no treatment for toxoplasma retinochoroiditis

BACKGROUND

Acute toxoplasma retinochoroiditis causes transient symptoms of ocular discomfort and may lead to permanent visual loss. Antibiotic treatment aims primarily to reduce the risk of permanent visual loss, recurrent retinochoroiditis, and the severity and duration of acute symptoms. There is uncertainty about the effectiveness of antibiotic treatment.

OBJECTIVES

To compare the effects of antibiotic treatment versus placebo or no treatment for toxoplasma retinochoroiditis.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision group Trials Register) (2016, Issue 1), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to February 2016), EMBASE (January 1980 to February 2016), Latin American and Caribbean Health Sciences Literature Database (LILACS) (January 1982 to February 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 did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 22 February 2016. We searched the reference lists of identified articles and contacted pharmaceutical companies for unpublished trials.

SELECTION CRITERIA

We included randomised controlled trials that compared any antibiotic treatment against placebo or no treatment. We excluded trials that included immunocompromised participants. We considered any antibiotic treatment known to be active against Toxoplasma gondii. Antibiotic treatment could be given in any dose orally, by intramuscular injection, by intravenous infusion, or by intravitreal injection.

DATA COLLECTION AND ANALYSIS

The primary outcomes for this review were visual acuity at least three months after treatment and risk of recurrent retinochoroiditis. Secondary outcomes were improvement in symptoms and signs of intraocular inflammation, size of lesion, and adverse events. We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

Four trials that randomised a total of 268 participants met the inclusion criteria. In all four studies antibiotic was administered orally.One study conducted in Brazil in both adults and children compared trimethoprim-sulfamexacocol over 20 months to no treatment and was judged to be at high risk of performance, detection, and attrition bias. The other three studies compared antibiotic treatment to placebo. We judged these three studies to be at a mixture of low or unclear risk of bias due to poor reporting. One study conducted in the US in adults studied pyrimethamine-trisulfapyrimidine for eight weeks; one study conducted in the UK in children and adults evaluated pyrimethamine for four weeks; and one study conducted in Brazil in adults investigated trimethoprim-sulfamethoxazole for 12 months. In the last study, all participants had active retinochoroiditis and were treated with antibiotics for 45 days prior to randomisation to trimethoprim-sulfamethoxazole versus placebo.Only the study in Brazil of trimethoprim-sulfamethoxazole over 12 months, in participants with healed lesions, reported the effect of treatment on visual acuity. People treated with antibiotics may have a similar change in visual acuity compared with people treated with placebo at one year (mean difference -1.00 letters, 95% confidence interval (CI) -7.93 to 5.93 letters; 93 participants; low-quality evidence).Treatment with antibiotics probably reduces the risk of recurrent retinochoroiditis compared with placebo (risk ratio (RR) 0.26, 95% CI 0.11 to 0.63; 227 participants; 3 studies; I(2) = 0%; moderate-quality evidence); similar results were seen for acute and chronic retinochoroiditis.The UK study of pyrimethamine for four weeks reported an improvement in intraocular inflammation in treated compared with control participants (RR 1.76, 95% CI 0.98 to 3.19; 29 participants; low-quality evidence). The study in Brazil of trimethoprim-sulfamethoxazole for 12 months stated that the severity of inflammation was higher in the comparator group when compared to the antibiotic-treated group but did not provide further details. In the US study of pyrimethamine-trisulfapyrimidine for eight weeks intraocular inflammation had almost completely resolved by eight weeks in all participants, however in this study all participants received steroid treatment.Two studies (UK and US studies) reported an increased risk of adverse events in treated participants. These were a fall in haemoglobin, leucocyte, and platelet count, nausea, loss of appetite, rash, and arthralgia.

AUTHORS' CONCLUSIONS

Treatment with antibiotics probably reduces the risk of recurrent toxoplasma retinochoroiditis, but there is currently no good evidence that this leads to better visual outcomes. However, absence of evidence of effect is not the same as evidence of no effect. Further trials of people with acute and chronic toxoplasma retinochoroiditis affecting any part of the retina are required to determine the effects of antibiotic treatment on visual outcomes.

Infectious Uveitis

Infectious uveitis is one of the most common and visually devastating causes of uveitis in the US and worldwide. This review provides a summary of the identification, treatment, and complications associated with certain forms of viral, bacterial, fungal, helminthic, and parasitic uveitis. In particular, this article reviews the literature on identification and treatment of acute retinal necrosis due to herpes simplex virus, varicella virus, and cytomegalovirus. While no agreed-upon treatment has been identified, the characteristics of Ebola virus panuveitis is also reviewed. In addition, forms of parasitic infection such as Toxoplasmosis and Toxocariasis are summarized, as well as spirochetal uveitis. Syphilitic retinitis is reviewed given its increase in prevalence over the last decade. The importance of early identification and treatment of infectious uveitis is emphasized. Early identification can be achieved with a combination of maintaining a high suspicion, recognizing certain clinical features, utilizing multi-modal imaging, and obtaining specimens for molecular diagnostic testing.

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.

Choroidoretinal granuloma in a young female patient

A 16-year-old Brazilian female patient presented with blurring of vision in the right eye. Corrected visual acuity was OD 2/20, OS 20/20. Afferent pupillary defect was absent and anterior segment examination revealed anterior uveitis. Fundus examination showed light vitritis and a raised grey-white granuloma located at posterior pole with focal serous retinal detachment on optical coherence. Indocyacnine green angiography disclosed a complete mask effect in granuloma's area. Differential diagnoses were infectious (bacterial, viral, fungal and parasites) diseases, systemic inflammatory diseases, tumours. Blood serologies (HIV, toxoplasma, Borrelia, cytomegalovirus (CMV), herpes simplex virus (HSV), varicella-zoster virus (VZV), rubeola) showed positive results for IgM and IgG for toxoplasma, and anterior chamber tap (PCR for toxoplasma, CMV, HSV, VZV) revealed toxoplasma DNA. Anti-toxoplasma therapy, pyrimethamine, sulfadiazine and calcium folinate, was administered immediately. On follow-up granuloma regression was observed, with complete visual restoration. This case demonstrates a clinically challenging posterior pole granuloma.

Antibiotics for human toxoplasmosis: a systematic review of randomized trials

The efficacy of different treatment regimens in clinical syndromes of toxoplasmosis were assessed by conducting a systematic review of published randomized clinical trials through extensive searches in MEDLINE, EMBASE, and SCOPUS with no date limits, as well as manual review of journals. Outcome measures varied depending on the clinical entity of toxoplasmosis. Risk of bias was evaluated and quality of evidence was graded. Fourteen randomized trials were included of which one was a non-comparative study. One well-designed trial showed that trimethoprim-sulphamethoxazole was more effective than placebo for clinical recovery of toxoplasmic lymphadenopathy in immunocompetent hosts. For toxoplasmic encephalopathy, efficacy of pyrimethamine+sulphadiazine and trimethoprim+sulphamethoxazole were similar, whereas pyrimethamine+sulphadiazine versus pyrimathamine+clindamycin showed no difference, irrespective of the outcome. Intravitreal clindamycin+dexamethasone and conventional treatment with oral pyrimethamine+sulphadiazine had similar efficacy with regard to all outcome measures in ocular toxoplasmosis, and intravitreal therapy was found to be safe. Adverse effects seemed more common with pyrimethamine+sulphadiazine. Most trials for encephalitis and ocular manifestations had a high risk of bias and were of poor methodological quality. There were no trials evaluating drugs for toxoplasmosis in pregnancy, or for congenital toxoplasmosis. Pyrimethamine+sulphadiazine is an effective therapy for treatment of toxoplasmic encephalitis; trimethoprim+sulphamethoxazole and pyrimethamine+clindamycin are possible alternatives. Treatment with either oral or intravitreal antibiotics seems reasonable for ocular toxoplasmosis. Overall, trial evidence for the efficacy of these drugs for toxoplasmosis is poor, and further well-designed trials are needed.