Effects of Sulfamethoxazole on Murine Ocular Toxoplasmosis in Interferon-γ Knockout Mice

PURPOSE

To evaluate the effects of sulfamethoxazole (SMX) on experimental ocular toxoplasmosis by quantitative competitive polymerase chain reaction (QC-PCR) assay.

METHODS

Wild-type (WT) C57BL/6 and WT BALB/c mice and interferon-gamma knockout (GKO) mice were infected orally with Toxoplasma gondii of the Fukaya strain. Mice were classified into groups. The first group (G1) remained untreated, the second group (G2) had a short SMX treatment period, and the third group (G3) received treatment continuously. WT and GKO mice were divided into G1 and G3, and G1, G2, and G3, respectively. T. gondii burdens were evaluated by QC-PCR assay. The effect on stage distribution was analyzed by reverse transcription-PCR.

RESULTS

SMX significantly decreased mortality among the infected WT C57BL/6 and GKO mice. In WT G1 mice, T. gondii DNA was detected in all organs and tissues, although in G3 mice it was detected only in the brain. In GKO C57BL/6 G1 mice, the protozoan proliferated much more actively than in the WT mice. In the GKO C57BL/6 G2 mice, the number of T. gondii was less than in G1 during the treatment, although the protozoan reappeared after cessation of treatment. In GKO C57BL/6 G3 mice, T. gondii DNA was detected in the brain, optic nerve, and retina, but not in the iris, choroid, sclera, and blood. In GKO BALB/c mice, the patterns of the kinetics of protozoan abundance in various organs were similar or were milder than those in GKO C57BL/6 mice. In SMX-treated GKO mice, the percentage of bradyzoites increased and that of tachyzoites decreased in the organs and tissues.

CONCLUSIONS

SMX decreased the parasitic load in both WT and GKO mice. SMX decreased the tachyzoite load but did not completely eliminate bradyzoites in GKO mice. The present mouse model was used successfully to assess treatment effects in a quantitative fashion.

Toxoplasmosis

Toxoplasmosis is the most common cause of posterior uveitis in immunocompetent subjects. The infection can be congenital or acquired. Ocular symptoms are variable according to the age of the subject. For instance, young children present with reduced visual acuity, strabismus, nystagmus, and leucocoria, while teenagers and adults complain of decreased vision, floaters, photophobia, pain, and hyperemia. Toxoplasmic retinochoroiditis typically affects the posterior pole, and the lesions can be solitary, multiple or satellite to a pigmented retinal scar. Active lesions present as grey-white focus of retinal necrosis with adjacent choroiditis, vasculitis, hemorrhage and vitreitis. Cicatrization occurs from the periphery towards the center, with variable pigmentary hyperplasia. Anterior uveitis is a common finding, with mutton-fat keratic precipitates, fibrine, cells and flare, iris nodules and posterior synechiae. Atypical presentations include punctate outer retinitis, neuroretinitis, papillitis, pseudo-multiple retinochoroiditis, intraocular inflammation without retinochoroiditis, unilateral pigmentary retinopathy, Fuchs'-like anterior uveitis, scleritis and multifocal or diffuse necrotizing retinitis. The laboratory diagnosis of toxoplasmosis is based on detection of antibodies and T. gondii DNA using polymerase chain reaction (PCR). Toxoplasmosis therapy includes specific medication and corticosteroids. There are several regimens, with different drug combinations. Medications include pirimetamine, sulfadiazine, clindamycin, trimethoprime-sulphamethoxazol, spiramycin, azithromycin, atovaquone, tetracycline and minocycline. The prognosis of ocular toxoplasmosis is usually good in immunocompetent individuals, as long as the central macula is not directly involved.

Acometimento ocular em pacientes com AIDS e toxoplasmose do sistema nervoso central: antes e depois do HAART

PURPOSE

To describe the ophthalmologic involvement in patients with Acquired Immunodeficiency Syndrome-AIDS and central nervous system toxoplasmosis comparing the period before and after highly active antiretroviral therapy (HAART).

METHODS

In a retrospective study, we compared 118 Acquired Immunodeficiency Syndrome patients with central nervous system toxoplasmosis who were examined at our institution before highly active antiretroviral therapy (from 1994-1996) with 24 patients with Acquired Immunodeficiency Syndrome and central nervous system toxoplasmosis who were being treated with highly active antiretroviral therapy (from 1996-1999). All patients were submitted to a complete ophthalmological examination as well as specific tests to confirm the diagnosis and there was no intersection between the groups.

RESULTS

In the pre-highly active antiretroviral therapy group, it was found that 23% of the patients with central nervous system toxoplasmosis had also ocular toxoplasmosis. Ocular involvement was bilateral in 37.2% of the cases. In the group of patients receiving highly active antiretroviral therapy, who had an average CD4 of 256 cells/mm(3) and average of viral load of 52,620 copies, 16.6% had concomitant ocular and central nervous system toxoplasmosis. Ocular involvement was bilateral in 50% of the cases.

CONCLUSIONS

Acquired Immunodeficiency Syndrome patients with central nervous system toxoplasmosis have a frequent association with ocular toxoplasmosis. Although the incidence of opportunistic infections has decreased since the introduction of recent antiretroviral therapeutic strategies ocular toxoplasmosis continues to be frequent in patients with cen.ral nervous system toxoplasmosis.

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.

Reactivation of Ocular Toxoplasmosis After LASIK

PURPOSE

To report a reactivation of ocular toxoplasmosis after LASIK.

METHODS

Case report of a 34-year-old man who underwent bilateral LASIK. The posterior segment examination revealed an old toxoplasmosis scar in the retinal periphery of the right eye.

RESULTS

Uncorrected visual acuity improved postoperatively, and the patient was satisfied. However, 52 days after the procedure, he complained of loss of visual acuity in his right eye. Examination revealed signs of anterior uveitis, vitreitis, and active chorioretinal lesion satellite of the old toxoplasmosis scar. The patient was treated with a multidrug regiment with resolution of the vitreous and lesion activity.

CONCLUSIONS

Toxoplasmosis reactivation may develop after LASIK.

[Ocular toxoplasmosis: our experience]

Ocular toxoplasmosis can be a progressive and recurring disease that can threaten visual function. Retinochoroiditis develops gradually weeks to years after subclinical congenital toxoplasmosis; this is the preponderant form, which is frequently bilateral; with healing, white or dark-pigmented scars may result. Toxoplasmosis acquired in older children and adults rarely progresses to retinochoroiditis; it is generally unilateral. We report the results of a clinical study concerning 16 patients with ocular toxoplasmosis observed for the first time in the period from 1992 to 2004 and followed up until today. The patients came to the Department of Infectious Diseases of the Second University of Naples. We studied 16 patients, 10 of whom were females; 11 cases presented ocular signs of congenital toxoplasmosis, while in 5 cases ocular impairment was related to an acquired toxoplasmosis. Only one case of congenital toxoplasma chorioretinitis was symptomatic at birth: it was complicated by microphthalmia and strabismus, calcifications in the brain and epilepsy; 10 congenital cases were asymptomatic at birth and were recognized after several years because of a reactivation of infection. In 5 patients congenital chorioretinitis was bilateral, with presence of scars in the contralateral eye. The 5 cases of acquired toxoplasma retinitis were ascertained by anamnestic, serologic and ophthalmologic examinations; in 4 of them the lesion was typical and unilateral; the 5th case was a 6-year-old boy with acquired toxoplasma bilateral neuroretinitis. 13/16 cases of ocular toxoplasmosis were treated with the combination of pyrimethamine, sulfadiazine; they were followed up and re-treated if necessary. The therapy was curative in each case. Our experience confirms that late-onset retinal lesions and relapse can occur many years after birth but that the overall ocular prognosis is satisfactory when congenital damage is recognized early and treated appropriately. Prevention of congenital and acquired toxoplasmosis is very important in controlling ocular toxoplasmosis.

[Postnatal follow-up of infants born to mothers with certain Toxoplasma gondii infection: evaluation of prenatal management]

The clinical management of perinatal toxoplasmosis involves a gynaecologist during pregnancy and a neonatologist after delivery. Then, in the absence of a uniform approach, early evaluation of infected infants requires a thorough long-term follow-up also in asymptomatic children, who have to be observed for at least one year due to unpredictable sequelae in later life. We retrospectively analyzed pregnancy management of 54 women with certain infection from Toxoplasma gondii (TG) and prospectively enrolled their infants to compare prenatal management with postnatal clinical outcome. All mothers with seroconversion for TG infection were from the Palermo area and were retrospectively analyzed, whereas their newborns referred to G. Di Cristina Children Clinical Hospital between 1999-2004 were prospectively enrolled in a 48-month follow-up. Timing of infection was dated for 24 women (45%) to the first trimester, 18 (33%) to the second and 12 (22%) the third. The maternal-fetal transmission rate was 17.2%. Prenatal diagnosis from amniotic fluid was performed in 25/54 pregnant subjects and showed positive results in 6. Despite diagnosis of TG infection, 9 women were untreated and only 2 with positive amniocentesis received combined therapy. 10/55 enrolled infants were infected and half of them were preterm and/or SGA at birth. None showed peculiar signs of TG at birth but 4 had abnormalities during the follow-up. 9/10 infected children were born to mothers who had undergone neither amniocentesis nor combined therapy.

CONCLUSIONS

Our work confirms the difficulty of applying standardized therapeutic protocol for TG infection during pregnancy. The asymptomatic course of TG infection at birth confirms the importance of an instrumental long-term follow-up to identify typical TG lesion to prevent sequelae.

Ocular manifestations in congenital toxoplasmosis

BACKGROUND

Retinochoroiditis is the most common ocular manifestation of congenital toxoplasmosis, but other associated ophthalmological pathologies can also occur. The aim of this study was to determine the nature of the latter in treated cases of the disease and to assess their impact on visual function.

METHODS

Four hundred and thirty consecutive children with serologically confirmed congenital toxoplasmosis were included in this study. Data were prospectively collected using standardized ophthalmological assessment forms. The presence of retinochoroiditis and of associated pathologies was ascertained, and their impact on visual function was assessed.

RESULTS

After a median follow-up of 12 years [range 0.6-26 years], 130 children manifested retinochoroiditis. We detected 22 foci of retinochoroiditis at birth and 264 additional ones during the follow-up period. Of these, 48 (17%) were active when first diagnosed. Twenty-five of the 130 children (19%) had other associated ocular pathologies. Of these, 21 (16%) had a strabismus, which was due to macular lesions in 86% of the cases; 7 (5.4%) presented with unilateral microphthalmia, and 4 (3%) with cataracts. Most of these events were detected after the onset of retinochoroiditis. None of the children presented with ocular involvement in the absence of chorioretinal lesions. Macular lesions occurred more frequently in children with associated pathologies (p<0.0001), and associated pathologies were likewise more common in individuals with macular lesions (p=0.0003). Visual impairment occurred in 31/130 cases, and in all but 3 of these eyes it was due not to an associated pathology but to macular retinochoroiditis.

CONCLUSIONS

At the end of the follow-up period, ocular involvement existed in 30% of the treated children with congenital toxoplasmosis. Associated eye pathologies were manifested less frequently than anticipated. They may occur later in life and are an indirect marker of the severity of congenital toxoplasmosis, but they do not have a direct impact on visual acuity. The overall functional prognosis of congenital toxoplasmosis is better than would be expected on the basis of literature findings, with only 2 of the 130 children suffering bilateral visual impairment.

Recurrent secondary frosted branch angiitis after toxoplasmosis vasculitis

PURPOSE

To describe a case of recurrent frosted branch angiitis after treatment of ocular toxoplasmosis.

METHODS

In a 6-year-old boy, we found perivascular, creamy, patchy, retinal sheathing in both eyes without any focal necrotizing retinochoroiditis or scarring. IgM antibodies for toxoplasma gondii were also found. The patient was treated with antitoxoplasmosis medication and a systemic steroid.

RESULTS

Several years after treatment of the toxoplasmosis, frosted branch angiitis occurred twice without any retinal scarring or serological evidence of toxoplasmosis. After systemic steroid therapy, the angiitis improved without further complications.

CONCLUSIONS

Toxoplasmic retinal vasculitis should be considered as a cause of frosted branch angiitis.

Necrotising retinopathies simulating acute retinal necrosis syndrome

AIM

To determine an aetiological diagnosis in patients presenting with necrotising retinopathies that simulate acute retinal necrosis (ARN).

METHODS

Retrospective non-comparative case series. The charts of 16 patients presenting with a clinical impression of ARN at Pitie-Salpetriere Hospital, Paris, France, between 1994 and 1999, who required initial antiviral therapy were reviewed. All of the patients had extensive laboratory tests. Anterior chamber paracentesis was performed on 14 patients and evaluated by polymerase chain reaction (PCR) and/or the Witmer-Goldmann coefficient to determine the cause of retinitis. Three of the 14 cases also had diagnostic vitrectomy. Responses to specific treatment, initiated based on laboratory results, and the final outcome were evaluated.

RESULTS

Seven of the 16 patients were female and nine were male. The retinitis was bilateral in five patients and unilateral in 11 patients. The average age of the patients at presentation was 53.6 years. 13 patients were immune deficient for various reasons. Upon initial presentation, the patients' visual acuities were less than 20/200 in 68% of the affected eyes. The final diagnoses, based on laboratory data and therapeutic response were toxoplasmic retinochoroiditis (62.5%), syphilitic retinitis (12.5%), aspergillus endophthalmitis (12.5%), Behcet's disease (6.2%), and intraocular lymphoma (6.2%). Visual acuity was stabilised or improved in 12 patients (75%). Two patients with aspergillosis died despite antifungal therapy.

CONCLUSIONS

Toxoplasmic retinochoroiditis is the major cause of retinal necrosis that simulates ARN, and PCR analysis of the aqueous humour is helpful in establishing the diagnosis. Such atypical toxoplasma retinochoroiditis may be associated with poor visual outcome.

The HIV RNA Levels of Plasma and Ocular Fluids in AIDS Patients with Ophthalmic Infections

The aim of the present study was to evaluate the impact of highly active antiretroviral therapy (HAART) on HIV viral load of plasma and intraocular fluids in AIDS patients with ophthalmic opportunistic infections. We further compared the treatment effect of HAART on these patients. From June 1997 to July 2003, we examined and followed up the ophthalmic conditions of 49 patients receiving HAART with ophthalmic diseases during this period. The method of reverse-transcriptase polymerase chain reaction was used to detect and monitor HIV load in plasma and/or aqueous humor of AIDS patients. Before HAART, the HIV levels in the plasma and aqueous humor in 8 AIDS patients with ophthalmic opportunistic infections were significantly higher than those in 6 patients with HIV-related retinopathy (p < 0.05). Compared to the eye findings and clinical improvement, HIV loads of aqueous humor in 10 of 14 AIDS patients (6 with HIV-related retinopathy, 5 with cytomegalovirus retinitis, 2 with toxoplasmic retinitis and 1 with cryptococcal chorioretinitis) declined to undetectable levels (< 400 copies/ml) after 4-8 months of HAART. HIV virus levels in the plasma of AIDS patients were significantly decreased, and the CD4 counts of these patients were significantly increased (Wilcoxon test) after initiation of HAART.

[Stevens-Johnson's syndrome after treatment for ocular toxoplasmosis]

CLINICAL CASE

We present a case of a 9 year-old male, who was treated with sulfadiacine, pirimetamine and folinic acid following diagnosis of an active toxoplasmic chorioretinitis. After 9 days of treatment he developed serious multiorganic mucocutaneous lesions and was diagnosed with Stevens-Johnson's syndrome.

DISCUSSION

Stevens-Johnson's syndrome is a potentially fatal multiorganic disease, where drugs are clearly linked as causal factors. Fifty per cent of cases progress to severe ocular disease. The multiorganic aspect of the disease and its severity demand an early diagnosis and a multidisciplinary treatment.

Photodynamic therapy with verteporfin for subfoveal choroidal neovascularization secondary to toxoplasmic chorioretinal scar

BACKGROUND

To assess the effect of photodynamic therapy in the treatment of subfoveal choroidal neovascularization consecutive to a toxoplasmic chorioretinal scar.

HISTORY AND SIGNS

Three patients with a previous history of toxoplasmic chorioretinal scar noticed a decrease in visual acuity and metamorphopsia. Fundus examination and fluorescein angiography revealed the presence of subfoveal choroidal neovascularization at the edge of the toxoplasmic chorioretinal scar.

THERAPY AND OUTCOME

The first patient, aged 78, was treated by photodynamic therapy followed by three subsequent treatments of feeder vessel by laser photocoagulation. Visual acuity decreased during follow-up in the presence of recurrence of choroidal neovascularization and subretinal fibrosis. The second patient, a 20-year-old lady, was treated with three sessions of photodynamic therapy for a subfoveal choroidal neovascularization related to a toxoplasmic scar. Visual acuity was stabilized on the last follow-up visit at 0.3. The third patient, aged 53, received four treatments with photodynamic therapy at an interval of 3 - 4 months. choroidal neovascularization was stabilized and the last visual acuity was 0.2.

CONCLUSIONS

This preliminary report suggests that photodynamic therapy with verteporfine may be an effective therapeutic modality for subfoveal choroidal neovascularization related to a toxoplasmic chorioretinal scar. Further assessment is needed in order to confirm this preliminary findings.

Branch retinal arterial occlusion associated with toxoplasmic chorioretinitis

BACKGROUND

Ocular toxoplasmosis can cause a variety of retinal vascular changes including branch retinal arterial occlusion, which is a rare complication of the disease.

PATIENT AND METHODS

We report a case of toxoplasmic chorioretinitis in a pregnant woman, who developed branch retinal arterial obstruction adjacent to the active chorioretinitis lesion.

RESULTS

The patient received an appropriate steroid and antibiotic treatment and the retinitis lesion resolved over a six-week period. At two months after diagnosis, visual acuity in her right eye was 20/30 and there was a hyperpigmented scar at the site where active retinitis had been observed.

CONCLUSION

Especially in young patients with branch retinal vascular occlusion associated with posterior uveitis, the diagnosis of ocular toxoplasmosis should be kept in mind and serologic test results should be obtained.

Reactivation of ocular toxoplasmosis in fellow unaffected eye

PURPOSE

To report a case of reactivation of ocular toxoplasmosis in fellow unaffected eye.

METHODS

Case report.

RESULTS

A 15 year old girl, known to have right ocular toxoplasmosis previously, has presented with one week history of sudden left visual deterioration and pan uveitis. Her condition was improved on intensive steroid treatment.

CONCLUSIONS

Reactivation of such lesion in fellow unaffected eye is quite rare. Various choices of treatment are available and there are also different techniques to treat. A review of treatment based on this pathology is briefly discussed.

Fundus-Quiz 2003

6 cases with pathognomonic fundus pathologies are presented and discussed using multiple-choice questions.

Acute acquired toxoplasma retinitis may present similarly to unilateral acute idiopathic maculopathy

PURPOSE

To describe a patient with acquired toxoplasma retinitis that shared similarities with unilateral acute idiopathic maculopathy.

DESIGN

Interventional case report.

METHODS

Interventional case report.

RESULTS

A 39-year-old woman presented with sudden unilateral vision loss in the right eye after a flu-like illness. She had retinitis involving the fovea, subretinal fluid, thickening of the retinal pigment epithelium, and a few vitreous cells; the retinitis resolved with antitoxoplasma antibiotic treatment.

CONCLUSIONS

Acute acquired toxoplasma retinitis may present similarly to unilateral acute idiopathic maculopathy.

Diagnostic approaches to severe, atypical toxoplasmosis mimicking acute retinal necrosis

PURPOSE

To describe the means of diagnosis and clinical features of atypical toxoplasmic chorioretinitis mimicking acute retinal necrosis.

DESIGN

Observational case series.

PARTICIPANTS

Twenty-two patients (25 eyes) with widespread chorioretinitis resulting from toxoplasmosis examined between 1990 and 2001.

TESTING

Patients were diagnosed by various techniques, including polymerase chain reaction (PCR) of aqueous and vitreous, serum and intraocular antibody determination, culture of intraocular fluid, retinal biopsy, histopathologic examination, therapeutic trial of antibiotics active against toxoplasmosis, or a combination thereof.

MAIN OUTCOME MEASURES

The primary outcome measure was diagnosis of disseminated toxoplasmic chorioretinitis by any combination of tests or by empiric use of specific antibiotics. The secondary outcome measure was visual and anatomic outcome of treatment.

RESULTS

Mean age was 53.5 years (range, 19-77 years), with a median of 59.5 years. There were 9 women and 13 men. Six patients were infected with HIV, and 3 patients, 1 with HIV, had bilateral disease. Mean initial vision was 20/110 (median, 20/400; range, 20/20 to no light perception [NLP]). Sixteen patients (73%) had received oral or injectable corticosteroids and 11 (50%) had received antiviral therapy before the diagnosis of toxoplasmosis. Diagnosis was made solely by clinical response to antitoxoplasmosis medications in 4 patients. Sixteen patients were diagnosed based on evaluation of intraocular fluids and tissue by antibody determinations, culture, PCR, histopathologic examination, or a combination thereof. Visual acuity improved after treatment in 7 of 25 eyes (28%). Mean final visual acuity was 20/156 (median, 20/2500; range, 20/30 to NLP). Anatomically, 18 of 23 eyes with follow-up had healed or improved chorioretinitis. Retinitis was progressive in 1 eye, 2 eyes were enucleated, and 2 were phthisical.

CONCLUSIONS

Diagnosis of atypical toxoplasmic chorioretinitis that mimics viral retinitis can be accomplished by several means. Prompt diagnosis may help avoid poor visual and anatomic outcomes after prolonged initial treatment with oral prednisone or antiviral medications.

Photodynamic therapy-treated choroidal neovascular membrane secondary to toxoplasmic retinochoroiditis

PURPOSE

To report the result of photodynamic therapy with Visudyne (PDT) on a child with choroidal neovascular membrane (CNV) secondary to toxoplasmic retinochoroiditis.

METHODS

An 11-year-old child with a unilateral lowering of visual acuity secondary to an extrafoveal choroidal neovascular membrane was submitted to PDT.

RESULTS

One week after PDT, the patient's vision had improved from 10/160 to 20/70, with marked improvement in the angiographic findings. The CNV evolved with decreasing of leakage until 45 days after operation, when it regressed to a chorioretinal scar formation, with final vision of 20/25.

CONCLUSION

PDT promoted an early recovery of visual acuity in an eye with choroidal neovascularization secondary to toxoplasmic retinochoroiditis.

Frosted branch angiitis and late peripheral retinochoroidal scar in a patient with acquired toxoplasmosis

PURPOSE

To report a case of acute frosted branch angiitis associated with acquired toxoplasmosis in which a late peripheral chorioretinal scar developed.

RESULTS

A 32-year-old man without systemic symptoms presented with sudden visual loss in his left eye. Examination demonstrated frosted branch angiitis without necrotizing chorioretinitis. Serologic tests showed elevated Toxoplasma gondii-specific immunoglobulin M antibody titers. Antitoxoplasmic therapy and oral steroids healed the ocular inflammation. In a follow-up visit one year later, a peripheral chorioretinal scar was noted.

CONCLUSIONS

Acute frosted branch angiitis without focal necrotizing chorioretinitis can be a manifestation of acquired toxoplasmosis. This could be an important, and sometimes forgotten, sign of the disease.

[Treatment difficulties in ocular toxoplasmosis]

PURPOSE

To determine the increased incidence of ocular infection with Toxoplasma gondii, the variety of ocular manifestations and therapeutical problems of this potential blind disease. We analyzed 22 patients hospitalized in our clinic in last 2 years at whom clinical diagnosis was confirmed by positive serological tests. Is discussed the correlation between serum level antibody(IgG and IgM) and ocular manifestations and the opportunity of beginning specific treatment depend on these two parameters.

CONCLUSIONS

The incidence of ocular toxoplasmosis is increasingly, the ophthalmologist must be open on atypical manifestations of this disease. The treatment remains controversial, we believe that it must be specific and correlated with ocular lesions evolutions and serum antibody level in time.

Ocular toxoplasmosis: a global reassessment. Part II: disease manifestations and management

PURPOSE

To update clinical information about ocular toxoplasmosis. Part II reviews the spectrum of disease manifestations and factors that influence severity of disease. Implications for disease management are discussed.

DESIGN

Literature review.

METHODS

Selected articles from the medical literature, information from several recent scientific meetings, and the author's personal experiences were reviewed critically in preparation for the LX Edward Jackson Memorial Lecture.

RESULTS

The appearance of toxoplasmic retinochoroiditis lesions varies with duration of active retinal infection and intensity of inflammation. Severe ocular disease occurs in immunocompromised hosts. Older patients who are recently infected with Toxoplasma gondii may have a higher prevalence of ocular involvement and more severe ocular disease because of altered host defenses. Most disease-producing isolates of T. gondii belong to one of three clonal lineages (types I, II, III); type I has been associated with severe disease in both animals and human beings. Many observational studies suggest a benefit of short-term antimicrobial therapy for toxoplasmic retinochoroiditis in immunocompetent patients, although the efficacy of these treatments has not been proven in randomized clinical trials. Intermittent trimethoprim/sulfamethoxazole treatment was associated with fewer recurrences than placebo during a 20-month randomized clinical trial.

CONCLUSIONS

Variations in disease characteristics may be related to host, parasite, or environmental factors. The genotype of the infecting parasite appears to be an important determinant of disease severity in immunocompetent patients. Secondary prophylaxis may reduce the rate of recurrences in high-risk patients. A better clinical understanding of ocular toxoplasmosis can lead to more effective prevention and treatment strategies.