Acquired Ocular Toxoplasmosis: a Case Report and Review of the Literature.

BACKGROUND: Toxoplasmosis is a zoonotic illness caused by Toxoplasma gondii. Ocular infection frequently manifests as acute necrotizing retinal chorioretinitis. In this paper, we describe a case of retinal chorioretinitis caused by Toxoplasma gondii infection, as well as the most recent diagnostic and treatment techniques. METHODS: Serum and vitreous fluid were collected and analyzed, and PCR for Toxoplasma gondii DNA, ELISA for Toxoplasma gondii IgG and Goldmann-Witmer coefficient, fundus fluorescein angiography (FFA), indocyanine green angiography (ICGA), and fundus autofluorescence were done (FAF). RESULTS: Toxoplasma gondii DNA (-), serum and vitreous IgG from Toxoplasma gondii (+) cells, and the Goldmann-Witmer coefficient of Toxoplasma gondii were all considerably enhanced, indicating Toxoplasma gondii infection. Antiparasitic infection in combination with an anti-inflammatory glucocorticoid were given, laser treatment of the fundus was provided, and the patient's condition has been stable with no indication of recurrence to date following conclusion of therapy. CONCLUSIONS: Toxoplasma gondii can infect the whole retina, causing variable degrees of visual impairment; thus, rapid diagnosis and tailored therapy are necessary to enhance prognosis and reduce disease recurrence.

Posterior segment findings by spectral-domain optical coherence tomography and clinical associations in active toxoplasmic retinochoroiditis.

Toxoplasmic retinochoroiditis is a common, potentially blinding parasitic infection. We sought to define the spectrum and frequency of signs of active toxoplasmic retinochoroiditis by spectral domain optical coherence tomography (SD-OCT), and to identify clinical associations. Ninety eyes of 90 individuals presenting consecutively to a tertiary referral uveitis service with active toxoplasmic retinochoroiditis and gradable SD-OCT scans were evaluated prospectively. SD-OCT features were collated, and associations with lesion location, primary versus recurrent episode, serological status, human immunodeficiency virus infection and best-corrected Snellen visual acuity were explored. Active toxoplasmic retinochoroiditis presented with thickened (65%) and hyperreflective (61%) retina, choroidal thickening (55%) and hyporeflectivity (61%), hyperreflective vitreous dots (80%) and deposits (36%), and posterior hyaloid thickening (35%) on SD-OCT. Most signs occurred with similar frequency across clinical groups. Retinal hyporeflectivity (17%) was significantly associated with a visual acuity of 20/200 or worse at resolution. Our observations demonstrate that active toxoplasmic retinochoroiditis has diverse SD-OCT signs and that none are universally present. Retinal hyporeflectivity-suggesting liquefactive necrosis-predicts poor visual outcome.

TOXOPLASMOSIS RETINOCHOROIDITIS MASQUERADING AS ENDOGENOUS ENDOPHTHALMITIS IN A CASE OF CONGENITAL LONG QT SYNDROME.

PURPOSE: To describe the diagnostic and treatment challenges of a case of presumed acquired macula-involving toxoplasmosis retinochoroiditis. METHODS: Case report of a woman with congenital long QT syndrome presenting with retinochoroiditis after undergoing a cardiac procedure. Laboratory analysis, ocular fluid biopsy, and multimodal imaging were obtained. RESULTS: Ophthalmic examination was significant for decreased vision and a macula-involving chorioretinal lesion concerning for endogenous endophthalmitis. Multimodal imaging showed a focal, full-thickness necrotizing process associated with vitritis, retinal edema, and choroidal thickening. Analysis of peripheral blood revealed elevated serum toxoplasma Immunoglobulin G titers. Blood cultures and a transesophageal echocardiogram were negative for endocarditis. Aqueous and vitreous specimens were negative for an infectious polymerase chain reaction panel, including toxoplasmosis and negative bacterial and fungal cultures. A diagnosis of presumed acquired toxoplasmosis retinochoroiditis was made and treated with a combination of oral and intravitreal antiparasitic medications resulting in healing of the retinochoroiditis. CONCLUSION: To the authors' knowledge, this is the first reported case of acquired toxoplasmosis retinochoroiditis in an immunocompetent patient with congenital long QT syndrome masquerading as endogenous endophthalmitis. The association of congenital long QT syndrome and a recent cardiac procedure with a risk for endogenous endophthalmitis complicated the diagnosis, clinical course, and treatment options. Our case emphasizes the importance of a thorough patient history, comprehensive clinical examination, and supportive multimodal imaging that were used to characterize the infectious process and guide empirical treatment. In addition, laboratory analysis, comanagement with other specialists, and evaluating the response to antitoxoplasma therapy were all instrumental in the eventual diagnosis and treatment of ocular toxoplasmosis in this atypical case.

Comparison of real-time PCR and nested PCR for toxoplasmosis diagnosis in toxoplasmic retinochoroiditis patients.

BACKGROUNDS: PCR is a proper technique that significantly improves toxoplasmosis diagnosis. However, a more sensitive technique is required. This study compared real-time PCR with nested PCR using B1, SAG-4, and MAG-1 bradyzoite genes to diagnose toxoplasmosis in toxoplasmic retinochoroiditis patients. METHODS: Blood samples were collected from 10 patients with active toxoplasmic chorioretinal lesions and 10 healthy individuals. Blood samples including peripheral blood mononuclear cells (PBMCs), serum and whole blood samples were used for DNA extraction. Serum was also used to detect anti-toxoplasma IgG and IgM antibodies. Nested PCR and real-time PCR were performed using B1, SAG-4, and MAG-1 target genes. RESULTS: Five (50%) out of the 10 patients were tested positive for toxoplasmosis with nested PCR using the PBMC samples. All the five patients tested positive with nested PCR were also tested positive for toxoplasmosis with real-time PCR using the PBMC samples. The real-time PCR results demonstrated that 9(90%) out of the 10 patients were positive based on B1 and the remaining one (10%) was positive only based on MAG-1. In general, of the patients, five (50%) were positive using SAG-4 and three (30%) were positive in term of MAG-1 using PBMCs with real-time PCR. CONCLUSION: It appears that PBMC samples have the best performance as the PCR extraction method and are a good source for toxoplasmosis diagnosis. The use of B22 and B23 target genes due to their high sensitivity and specificity along with bradyzoite genes are recommended for toxoplasmosis diagnosis using PBMC samples with real-time PCR.

Cladosporium Endogenous Endophthalmitis Mimicking Toxoplasma Retinochoroiditis.

Background: Endogenous fungal endophthalmitis is a sight-threatening condition with potentially devastating outcome. Hematogenous spread of the infective seedings is the route of infection. Infected individuals have usually a compromised immune status. The clinical picture of mycotic endogenous endophthalmitis is commonly seen as chorioretinitis. Candida is the most common fungus. Cladosporium causing endogenous endophthalmitis is a rare occurrence, with only a few cases published.Methods: The report includes study and management of a diabetic patient with endogenous cladosporium endophthalmitis mimicking toxoplasma retinochoroiditis.Results: Diagnosis was confirmed as Cladosporium Cladosporioides in vitreous and aqueous aspirate by polymerase chain reaction-based DNA sequencing. Patient was successfully managed with intravitreal and systemic voriconazole.Conclusion: Cladosporium can cause endogenous endophthalmitis and mimic toxoplasma retinochoroiditis. Vitreous biopsy can help in diagnosis in the absence of positive blood culture. Intravitreal voriconazole along with systemic voriconazole shows a good response.

Ocular Outcome of Brazilian Patients With Congenital Toxoplasmosis.

BACKGROUND: Retinochoroiditis is the most frequent manifestation of congenital toxoplasmosis. We aimed to describe the ocular outcome and factors that may influence the visual prognosis of these patients. METHODS: Cohort of patients with confirmed congenital toxoplasmosis seen between 1996 and 2017 in Porto Alegre, southern Brazil. RESULTS: Seventy-seven patients were included, of which 65 (85.5%) were identified by routine screening. Median age at the end of the follow-up was 10 years (minimum 2, maximum 25). Retinochoroiditis was present in 55 patients (71.4%). New retinochoroidal lesions developed after the first year of life in 77.8% of the patients who began treatment after the fourth month of life, compared with 35.2% among those treated before 4 months of life (relative risk = 0.45, 95% confidence intervals: 0.27-0.75, P = 0.02) and 33.3% among those treated before 2 months of life (relative risk = 0.42, 95% confidence intervals: 0.25-0.72, P = 0.01). There was a peak incidence of new retinochoroidal lesions between 4 and 5 years and another peak between 9 and 14 years, the latter only among girls. Thirty-four patients with retinochoroiditis were followed up for 10 years or more, and the school performance was appropriate in 28 (82.4%). CONCLUSIONS: The high incidence of new retinochoroidal lesions during the follow-up period indicates the importance of long-term follow-up of patients with congenital toxoplasmosis. Initiating treatment within the first 4 months of life, especially within the first 2 months, was a protective factor against the later development of retinochoroiditis. Despite the usual favorable prognosis, the high morbidity of congenital toxoplasmosis in Brazil was confirmed.

Pathogenesis of ocular toxoplasmosis.

Ocular toxoplasmosis is a retinitis -almost always accompanied by vitritis and choroiditis- caused by intraocular infection with Toxoplasma gondii. Depending on retinal location, this condition may cause substantial vision impairment. T. gondii is an obligate intracellular protozoan parasite, with both sexual and asexual life cycles, and infection is typically contracted orally by consuming encysted bradyzoites in undercooked meat, or oocysts on unwashed garden produce or in contaminated water. Presently available anti-parasitic drugs cannot eliminate T. gondii from the body. In vitro studies using T. gondii tachyzoites, and human retinal cells and tissue have provided important insights into the pathogenesis of ocular toxoplasmosis. T. gondii may cross the vascular endothelium to access human retina by at least three routes: in leukocyte taxis; as a transmigrating tachyzoite; and after infecting endothelial cells. The parasite is capable of navigating the human neuroretina, gaining access to a range of cell populations. Retinal Müller glial cells are preferred initial host cells. T. gondii infection of the retinal pigment epithelial cells alters the secretion of growth factors and induces proliferation of adjacent uninfected epithelial cells. This increases susceptibility of the cells to parasite infection, and may be the basis of the characteristic hyperpigmented toxoplasmic retinal lesion. Infected epithelial cells also generate a vigorous immunologic response, and influence the activity of leukocytes that infiltrate the retina. A range of T. gondii genotypes are associated with human ocular toxoplasmosis, and individual immunogenetics -including polymorphisms in genes encoding innate immune receptors, human leukocyte antigens and cytokines- impacts the clinical manifestations. Research into basic pathogenic mechanisms of ocular toxoplasmosis highlights the importance of prevention and suggests new biological drug targets for established disease.

Unilateral Acute Macular Toxoplasmic Chorioretinitis Associated with White Dot-Like Choroidal Involvement Demonstrated on Indocyanine Green Angiography

A 9-year-old otherwise healthy boy was examined due to a 4-day history of visual decline in his right eye. Ophthalmological examination revealed an area of active retinochoroiditis in the right macula. Indocyanine green angiography (ICGA) demonstrated multiple hypocyanescent dots surrounding the active lesion extending 360 degrees towards the equator. Optical coherence tomography angiography (OCTA) exhibited dark dots on the choriocapillaris slab over areas corresponding to the hypocyanescent dots detected with ICGA. Full systemic examination and laboratory investigations were carried out. Toxoplasma gondii serology was positive. The diagnosis of toxoplasmic chorioretinitis with white dot-like choroidal involvement was made. Trimethoprim/sulfamethoxazole, azithromycin, and oral prednisolone were administered orally. On repeated ICGA 2 weeks later, the scattered hypocyanescent dots were significantly fewer in number. A month later, right visual acuity was improved, the macular chorioretinitis focus had become inactive, an epiretinal membrane had formed, and the dark dots on the choriocapillaris slab of OCTA were markedly diminished. ICGA may be helpful to observe possible, subtle choroidal involvement in patients with toxoplasmic chorioretinitis.

Evolving Longitudinal Retinal Observations in a Cohort of Survivors of Ebola Virus Disease.

Importance: The 2-year ophthalmic sequelae of Ebola virus disease (EVD) in survivors of the 2013 to 2016 epidemic is unknown and may have public health implications for future outbreaks. Objective: To assess the potential for uveitis recurrence, the behavior of dark without pressure, and visual outcomes in a cohort of Sierra Leonean survivors of EVD 2 years following the 2013 to 2016 Ebola epidemic. Design, Setting, and Participants: Prospective, 1-year observational cohort study performed between 2016 and 2017 at 34 Military Hospital, Freetown, Sierra Leone. Participants included survivors of EVD who reported ocular symptoms since Ebola treatment unit discharge and were participants of a previous case-control study. Participants were invited for ophthalmic reexamination and finger-prick blood sampling for immunoglobulin G (IgG) to Toxoplasma gondii and HIV. Exposures: Ebola virus disease. Main Outcomes and Measures: Primary outcome measure: comparative ultra-widefield retinal imaging. Secondary outcome measures: visual acuity and detection of IgG to T gondii and HIV. Results: Of 57 survivors of EVD who underwent repeated ophthalmic evaluation, 37 were women (64.9%). Mean (SD) age was 31.9 (11.1) years. Median interval between first and last examination was 370 days (interquartile range [IQR], 365-397.5 days), and median time from discharge to last examination was 779 days (IQR, 732-821 days). Fifteen eyes of 10 survivors (17.5%) had retinal lesions secondary to EVD. No new EVD-associated retinal lesions were observed. Two survivors (3.5%) developed new posterior uveitis resembling toxoplasmosis chorioretinitis and 41 (73%) were seropositive for T gondii IgG. Areas of dark without pressure were observed either confined to the perimeter of Ebola retinal lesions (n = 7) and non-Ebola lesions (n = 2), involving extensive retinal areas adjacent to Ebola retinal lesions (n = 4) and non-Ebola lesions (n = 2) or in isolation (n = 6). Both expansion and regression of areas of dark without pressure were observed over the study period. Best eye-presenting visual acuity had mild or no visual impairment in 55 survivors (96.4%) 2 years following discharge. Conclusions and Relevance: Vision was maintained in survivors of EVD 2 years following discharge. Evolving regions of dark without pressure may be associated with EVD retinal lesions and might suggest the presence of an ongoing intraretinal stimulus, which may be associated with infective etiology. Treatment strategies should account for the possibility of toxoplasmosis chorioretinitis recurrence within survivors of EVD.

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

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

VITREOUS TREPONEMAL ANTIBODY AS A SUPPLEMENTARY TEST TO SEROLOGY FOR THE CONFIRMATION OF SYPHILITIC CHORIORETINITIS.

PURPOSE: To report the novel application of nontreponemal and treponemal antibody to confirm diagnosis of ocular syphilis from vitreous samples. METHODS: Two distinct case reports emphasizing the importance of confirmatory vitreous treponemal antibody. Multimodal imaging of patients was also applied. RESULTS: We report two distinct cases with positive serum treponemal antibody but opposing vitreous treponemal antibody results. One case with a positive vitreous test responded well to antisyphilitic treatment. By contrast, a case with a negative vitreous result was changed to serpiginous choroiditis, eventually cured by immunomodulatory treatment. CONCLUSION: Intraocular fluid analysis of nontreponemal and treponemal antibody may play an important role in ruling out suspected ocular syphilis in settings without a polymerase chain reaction facility, especially immunocompromised patients who are at risk of multiple infections. Further studies are needed to establish the sensitivity and specificity of nontreponemal and treponemal antibody test on vitreous samples.

Chorio-retinal toxoplasmosis: treatment outcomes, lesion evolution and long-term follow-up in a single tertiary center.

BACKGROUND: Ocular toxoplasmosis is a common cause of ocular inflammation worldwide. The aim of this study is to characterize the clinical outcomes and lesion evolution of patients with ocular toxoplasmosis and to compare the primary and reactivation subgroups. METHODS: A retrospective population-based cohort study at one uveitis-specialized tertiary referral center. Patients presenting with active ocular toxoplasmosis between the years 2007-2016 were included. Primary ocular toxoplasmosis and reactivations were compared. RESULTS: Included were 22 patients, 64% female with a mean age of 29 ± 18 years, 59% (n = 13) were primary, 9% (n = 2) congenital and 32% (n = 7) reactivations. Visual acuity improved from 0.38 ± 0.44 to 0.20 ± 0.27 LogMAR (P = 0.026) after a mean of 37 ± 33 months. Initial lesion size was 2.38 ± 1.1 optic disc areas, reducing to 1.56 ± 1.24 following 2 months (34% reduction, P = 0.028) and to 1.17 ± 0.87 disc areas following one year (51% reduction, P = 0.012). Patients with macula-threatening lesions had worse visual acuity (0.50 ± 0.46 vs. 0.05 ± 0.07 LogMAR, P = 0.047). Primary and reactivation subgroups had similar presentations, visual outcomes and recurrence rates (all P > 0.05). CONCLUSIONS: In this population, primary ocular toxoplasmosis was the most common presentation. Lesion size reduced during the initial months with limited change thereafter and a third of cases recurred. Macula-threatening lesions were associated with worse visual acuity, and no significant differences were seen between the primary and reactivation subgroups.

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.

Immune Mediators against Toxoplasma Gondii during Reactivation of Toxoplasmic Retinochoroiditis.

Purpose: The purpose of this article is to analyze possible associations between systemic and ocular cytokine levels and specific clinical ophthalmologic signs from patients with a reactivation of toxoplasmic retinochoroiditis (RTR). Methods: A total of 18 patients with an active RTR episode, 8 patients with inactive scars, and 14 control patients were included in the study. Serum samples and aqueous humor (AH) samples were analyzed for IFN (interferon)-γ, interleukin (IL)-10, and IL-6 levels by ELISA. Inflammation grade, location, and size of the retinochoroidal active lesion, sampling time, and time to resolution were recorded. Results: A significantly negative correlation between AH and serum levels of IFN-γ was detected (p < 0.05). Patients with an AH IFN-γ/IL-10 ratio lower than 1 were associated with the longest time to resolution and/or severe complications. Conclusion: Serum IFN-γ levels may be used as a prognostic marker for both time to resolution and the development of possible severe complications during a given RTR episode.

Swept-source optical coherence tomography and optical coherence tomography angiography in acquired toxoplasmic chorioretinitis: a case report.

PURPOSE: To describe swept-source optical coherence tomography and optical coherence tomography angiography retinal changes in a case of acute toxoplasmic chorioretinitis both at the time of diagnosis and after healing. CASE PRESENTATION: A 57-year-old white woman suffering from acquired toxoplasmic chorioretinitis underwent swept-source optical coherence tomography and optical coherence tomography angiography both at the time of diagnosis and after healing. In the acute phase of the disease, swept-source optical coherence tomography clearly showed retinal and choroidal involvement in the superficial retina and in the choroidal swelling. Optical coherence tomography angiography showed a complete loss of deep and superficial capillary networks and of choroidal vessels in the area of the inflammation. After healing, swept-source optical coherence tomography showed a retinal thinning of the area involved, with a subversion of retinal layers and no visible change at the choroid level. On the other hand, optical coherence tomography angiography showed the persistence of a vascular occlusion at the retina and choroid level. CONCLUSION: This is the first case in the optical coherence tomography angiography literature that shows the imaging of toxoplasmic chorioretinal lesions. This case confirms the involvement of the retina and choroid in toxoplasmic uveitis and the disruptive potential of such inflammation. The optical coherence tomography angiography performed after healing showed a persistent ablation of the retina, choriocapillaris, and choroidal vessels. The non-invasive optical coherence tomography angiography imaging technique may have diagnostic and prognostic value in regard to toxoplasmic uveitis.

Case report: a case of diffuse unilateral subacute neuroretinitis (DUSN) in a child.

BACKGROUND: Diffuse unilateral subacute neuroretinitis (DUSN) is a rare cause of posterior uveitis in the United Kingdom. It typically presents unilaterally in children and young adults but rarely bilateral cases have been reported. It is also rare to have multiple worms in the same eye causing the clinical picture. In this article, we present a challenging case of DUSN in a young girl unresponsive to conventional treatments suggesting the possibility of multiple worms being present in the same eye. CASE PRESENTATION: An 8-year-old girl presented with a 2-month history of headaches. On occasions the headaches were associated with redness and watering of her left eye. She denied any visual loss or visual symptoms. Her visual acuity was reduced to 6/30 in her left eye. Fundal examination revealed a unilateral chorioretinitis. Investigation did not reveal a specific cause for the chorioretinitis. Over 15 months her visual acuity improved to 6/9 but the fundal appearance changed and a diagnosis of DUSN was made. She was treated with focal laser, systemic anti-helminthic and immunosuppressive treatments but continued to develop new, active areas of chorioretinitis, raising the possibility of multiple worms in the sub-retinal space. There is also a concern as to other central nervous system (CNS) involvement given her significant and ongoing headaches. CONCLUSION: We present a challenging case of DUSN in a young girl; a condition that remains rare in the UK. She was unresponsive to both focal laser and systemic anti-helminthic and immunosuppressive treatments suggesting the possibility of multiple worms being present in the sub-retinal space. This case highlights the difficulties often encountered in the treatment of DUSN, even when a worm can be identified. Her visual prognosis is poor as there was ongoing recurrence of active chorioretinitis.

Assessment of ocular toxoplasmosis patients reported at a tertiary center in the northeast of Iran.

PURPOSE: Ocular toxoplasmosis, which is caused by the single-cell parasite Toxoplasma gondii, is currently the most significant cause of posterior uveitis in the world. No previous studies have described the prevalence and clinical features of ocular toxoplasmosis in the northeast of Iran. The purpose of the current study was to address this gap. METHODS: In this retrospective study, the medical records of 488 uveitis patients who presented to the Khatam-al-Anbia Eye Hospital of Mashhad University of Medical Sciences, a tertiary ophthalmology center in the northeast of Iran, between January 2013 and December 2015 were evaluated. The clinical features and risk factors of 99 (20%) consecutive patients with ocular toxoplasmosis were extracted. RESULTS: Ninety-nine including 53 (53.5%) female and 46 (46.5%) male patients with ocular toxoplasmosis were included in the analysis. Reduced vision (77%) and floaters (15.2%) were the most common presenting symptoms. The age category that was most affected by ocular toxoplasmosis was 20-40 years (range: 11-65 years) with a mean age of 27.2. All patients had retinochoroiditis, but just two had anterior uveitis. All of the extracted patients, with the exception of three patients, had unilateral involvement. None of the patients had any other medical disorders with the exception of one woman, who had diabetes. Only four recurring ocular toxoplasmosis patients were referred to the education hospital during the study. Serology data were available for just 32 patients, of which 31 (96.8%) were IgG positive, and 1 (3.2%) was IgM positive. CONCLUSION: Toxoplasma gondii was responsible for 20% of the patients of uveitis that presented to the largest ophthalmology center in the northeast of Iran. There is a high incidence of patients of ocular toxoplasmosis in the northeast of Iran, and it is a significant cause of uveitis and visual impairment in this area.