Retinal vasculitis in HLA-A29 birdshot retinochoroiditis, particularities and imaging narrative of an under-estimated and diagnostic component of the disease.

BACKGROUND: HLA-A29 birdshot retinochoroiditis (BRC) is a primary stromal choroiditis (PSC), the hallmark being the choroidal rice-shaped hypopigmented fundus lesions ("birdshot lesions"). BRC is characterised by dual independent retinal vasculitis and choroiditis, the former often preceding manifest choroidal lesions. The purpose of this study was to analyse the type and severity of retinal vasculitis and determine whether it represented a diagnostic contribution. Medical records of patients with the diagnosis of BRC examined in the uveitis clinic of the Centre for Ophthalmic Specialised care (COS) in Lausanne from 1994 to 2020, were retrospectively reviewed. All patients had a complete ophthalmic examination, including visual field testing, optical coherence tomography (OCT), and fluorescein (FA) and indocyanine green (ICGA) angiography. Key retinal angiographic features were assessed. The study also established the angiographic score for retinal (FA) compared to choroidal involvement (ICGA). Among the 2102 newly diagnosed patients, 33 (1.57%) were diagnosed as BRC. Of the 21 patients with sufficient data included, all exhibited bilateral retinal vasculitis, of which 5 (24%) had no "birdshot lesions" at presentation with ICGA however always showing choroidal involvement. FA characteristics included (1) profuse retinal exudation in 17/21 cases (81%), (2) macular oedema in 17 patients (81%) with foveolar sparing for 14 of them (82%), (3) thick sheathing/staining of large posterior pole vessels in 13 patients (62%) and (4) profuse disc hyperfluorescence in all 21 patients. (5) A specific feature was the so-called pseudo arterio-venous circulatory delay in 17/21 cases (81%). The FA angiographic score at presentation was 14.49 ± 5.1 equivalent to the ICGA angiographic score of 14.29 ± 3.6, and higher than in other chorioretinitis entities. Both angiographic scores decreased similarly after treatment with a slower response of the retinal involvement. CONCLUSIONS: Retinal vasculitis in BRC is often very pronounced and presents distinct angiographic features that help substantially in the diagnosis and understanding of the disease course. Retinal vasculitis can present initially as an isolated feature in absence of the characteristic "birdshot lesions". The presence of all or some of the specific FA features strongly orient towards BRC to seek confirmation by ICGA and the search for the HLA-A29 antigen.

Ocular Leptospirosis: Report of a Challenging Diagnosis.

PURPOSE: To report a challenging case of serologically confirmed posterior uveitis due to leptospirosis. METHODS: Review of medical records. RESULTS: Thirteen-year-old boy presented focal necrotizing retinochoroiditis after flood exposure. Laboratory work-up confirmed leptospirosis infection and proper antibiotic treatment was done. The patient evolved well. but during late follow-up he developed nummular keratitis. CONCLUSION: Leptospirosis is a possible etiology of necrotizing posterior uveitis. The use of antimicrobial therapy is controversial but was used in this case, in association with corticosteroids, leading to resolution of retinal inflammation. Despite treatment, the patient developed late corneal opacities, which did not lead to visual impairment.

Retinochoroiditis secondary to Rickettsia typhi infection: a case report.

BACKGROUND: To report a case of unusual presentation of retinochoroiditis caused by Rickettsia typhi in a patient without prior uveitis. CASE PRESENTATION: In this case, we describe a 24-year-old male soldier with no previous eye disease, who was referred to our ophthalmology department due to bilateral retinochoroiditis and vitritis. The patient initially presented with a paracentral scotoma in his right eye persisting for 7 days and scattered dark spots in his left eye for 2 days in June 2023. Preceding these ocular symptoms, he experienced a two-week episode of fever, headaches, night sweats, and rapid weight loss of 10 kg. A transient rash covered his body briefly. His mother had a history of recurrent eye inflammation. Physical examination revealed bilateral keratic precipitates on the lower corneal periphery, 1 + anterior vitreous cells, small retinal lesions and mild optic discs elevation. Fluorescein angiography indicated mild discs hyperfluorescence, and the clinically visible round punctate lesions on OCT showed inner retinal hyper-reflective lesion with a depth till outer plexiform layer possibly suggestive of a retinitis lesion. Laboratory tests were normal except thrombocytosis, elevated ESR, liver enzymes and ACE levels, with positive Rickettsia typhi serology tests. Rheumatology and infectious disease consultations ruled out autoimmune diseases, confirming Rickettsia typhi infection. Treatment included systemic doxycycline and prednisone, with improvement of visual acuity, ocular symptoms, OCT abnormalities and resolution of inflammation. Prednisone was discontinued, and after two months, additional improvement was seen clinically, with preserved retinal structures on OCT. CONCLUSION: This study explores retinochoroiditis as a rare ocular presentation of Rickettsia typhi, an unusual infection in the Middle East. Previously reported ocular manifestations include conjunctivitis, vitritis, post infectious optic neuropathy and a few cases of uveitis. Ocular symptoms followed systemic illness, highlighting the need for awareness among clinicians. Diagnosis relies on seroconversion, with fluorescein angiography and OCT aiding in assessment. Empiric doxycycline and systemic corticosteroid therapy is recommended. Ocular symptoms resolved in two months. Awareness of these ocular manifestations is essential for timely diagnosis and management. Further research is needed to fully understand this aspect of murine typhus.

Prevalence of ocular toxoplasmosis among people living with HIV: a systematic review and meta-analysis.

Aim: To determine the prevalence of ocular toxoplasmosis among people living with HIV through a systematic review and meta-analysis. Materials & methods: A literature search was conducted, estimating pooled prevalence and performing quality assessment, outlier, influential and meta-regression analyses. Results: Twenty-nine studies were included in the analysis, revealing that the rate of ocular toxoplasmosis among people living with HIV was 0.37% (95% CI: 0.2-0.6). Substantial heterogeneity was observed among the studies. Despite analyzing continuous variables, including year of publication, proportion of males, mean age and proportion of patients receiving antiretroviral therapy, no statistically significant associations were found. Conclusion: This study provides an overview of the prevalence of ocular toxoplasmosis in people living with HIV, emphasizing the need for further research to uncover factors contributing to its development.

This study looked at how common ocular toxoplasmosis, a type of parasitic infection, is among people living with HIV. We did this by reviewing other studies, combining their results and evaluating the quality of each study. We also looked for any unusual findings and other factors that might affect the prevalence of ocular toxoplasmosis. After analyzing 29 studies, we found that approximately 0.37% of people living with HIV had ocular toxoplasmosis, ranging from 0.2% to 0.6%. There was a significant variation in the results among the studies. Our study provides an overview of the prevalence of ocular toxoplasmosis in people living with HIV, highlighting the need for further research to identify the factors contributing to its development.

Ocular Autoimmune Systemic Inflammatory Infectious Study (OASIS) - Report 6: Dengue Uveitis at a Tertiary Eye Institution in Singapore.

OBJECTIVES: To identify the characteristics, treatment, and visual outcomes of dengue uveitis at a tertiary eye care centre in Singapore. METHODS: Retrospective case record review of all consecutive dengue uveitis patients (2004 to 2015) from the Ocular Autoimmune Systemic Inflammatory and Infectious Study (OASIS) database. RESULTS: Fifty-four patients were identified from the OASIS database. The most common ocular symptom was blurring of vision (n = 41, 75.9%), followed by floaters (n = 9, 17.0%), scotoma (n = 5, 9.3%), and metamorphopsia (n = 3, 5.7%). Scotoma based on history, Amsler grid, and perimetry accounted for 27 (50%) patients. Majority presented with either a posterior uveitis or retinal vasculitis (n = 51, 94.4%). Treatments ranged from close observation for spontaneous improvement, to the use of high-dose corticosteroids. CONCLUSIONS: Dengue uveitis may present with a spectrum of disease manifestations including posterior uveitis, vasculitis, and macula edema. Scotoma is significant and may be found on history taking, Amsler charting, and perimetry.

Ocular toxoplasmosis following anti-tumour necrosis factor-α therapy combined with oral methotrexate therapy: A case report and review of literature.

Purpose: To report a case of ocular toxoplasmosis following long-term treatment with adalimumab and review the literature on ocular toxoplasmosis following anti-Tumour necrosis factor-α therapy. Method: A retrospective chart review of A 21-year-old male who developed retinochoroiditis in his left eye following adalimumab therapy combined with oral methotrexate. Result: A known patient of juvenile idiopathic arthritis (JIA) on adalimumab and oral methotrexate for the last four years presented to us with a blurring of vision for the last 15 days. Fundus examination of the left eye revealed severe vitritis and two patches of retinochoroiditis in the inferior part of the fundus. Subsequent investigations confirmed it to be a case of toxoplasma retinochoroiditis, and he responded to anti-toxoplasma treatment. A review of literature on a similar topic revealed five such cases, and the index case was the first such report in patients with JIA. Conclusion: The index case highlights the importance of early recognition and management of opportunistic infections in patients receiving biologicals.

Clinical association and visual morbidity in uveitis with systemic diseases: An analysis from a tertiary ophthalmic center.

AIM: The aim of this study was to identify the incidence, etiology, most common presentations, complications, and the causes of visual loss in posterior uveitis (PU). MATERIALS AND METHODS: A retrospective study was conducted on a cohort of 125 patients with PU with a minimum follow-up of 6 months. Ocular evaluation consisted of slit-lamp examination, indirect ophthalmoscopy, tonometry, and refraction. Ancillary ophthalmic investigations such as fundus fluorescein angiography, optical coherence tomography, and B-scan ultrasonography were done. Laboratory tests were performed on blood on all patients and in aqueous humor samples obtained by anterior chamber paracentesis in cases of diagnostic dilemmas. All the data were analyzed using SPSS program. RESULTS: PU occurred in 61%. Infections were noted in 34% and autoimmune diseases in 27%. The most frequent presentation was choroiditis. The most common etiologies were tubercular uveitis in 50%, Toxoplasma retinochoroiditis in 23%, and autoimmune category of serpiginous choroiditis in 56% of patients. Complications occurred in 27% and were most commonly cystoid macular edema and macular scarring. Polymerase chain reaction (PCR), nested PCR, and real-time PCR on ocular fluids were required for diagnosis in 30%. A combination of laboratory investigations on blood and aqueous humor samples were confirmation in 88%. CONCLUSION: PU and its sequelae are known to be sight threatening and are associated with systemic diseases. They have diverse etiologies and presentations. Identification of etiology is important as management is diametrically opposite in infections and autoimmune diseases.

Atypical pattern of ocular toxoplasmosis: recurrent inner foveal toxoplasmic retinitis (rifter).

Failure to recognize the different possible clinical presentations of ocular toxoplasmosis may delay diagnosis and treatment, compromising visual prognosis. The aim of this paper is to describe an atypical pattern of ocular toxoplasmosis, not yet described. Five Brazilian patients, from 4 different referral centers, presented similar atypical pattern of ocular toxoplasmosis characterized by mild vitritis, foveal cavitation involving predominantly all retinal layers associated with adjacent inner retinal necrosis (a necrotizing retinitis with a persisting inner retinal tissue bridge and loss of subjacent retinal layers). The appearance of the OCT image resembling a "rift", led the authors to define this pattern as a Recurrent Inner Foveal Toxoplasmic Retinitis (RIFTER), which can be considered as a new description of an atypical pattern of toxoplasma retinochoroiditis, and clinicians should be aware of it and consider testing for toxoplasmosis in patients with similar findings.

Retinal ferroptosis as a critical mechanism for the induction of retinochoroiditis during ocular toxoplasmosis.

Toxoplasmosis is a major infectious disease, affecting approximately one-third of the world's population; its main clinical manifestation, ocular toxoplasmosis (OT), is a severe sight-threatening disease. Nevertheless, the diagnosis of OT is based on clinical findings, which needs improvement, even with biochemical tests, such as polymerase chain reaction and antibody detections. Furthermore, the efficacy of OT-targeted treatment is limited; thus, additional measures for diagnosis and treatments are needed. Here, we for the first time report a significantly reduced iron concentration in the vitreous humor (VH) of human patients infected with OT. To obtain further insights into molecular mechanisms, we established a mouse model of T. gondii infection, in which intravitreally injected tracer 57Fe, was accumulated in the neurosensory retina. T. gondii-infected eyes showed increased lipid peroxidation, reduction of glutathione peroxidase-4 expression and mitochondrial deformity in the photoreceptor as cristae loss. These findings strongly suggest the involvement of ferroptotic process in the photoreceptor of OT. In addition, deferiprone, an FDA-approved iron chelator, reduced the iron uptake but also ameliorated toxoplasma-induced retinochoroiditis by reducing retinal inflammation. In conclusion, the iron levels in the VH could serve as diagnostic markers and iron chelators as potential treatments for OT.

A new perspective in the treatment follow-up of toxoplasma retinochoroiditis: Infiltrate thickness measurement.

BACKGROUND: This study aimed to describe the spectral domain optical coherence tomography (SD-OCT) findings of active lesions in toxoplasma retinochoroiditis cases and to examine the changes in retinochoroidal infiltrate thickness after treatment. METHODS: A total of 21 newly diagnosed patients with ocular toxoplasmosis were included in this prospective study. A complete ophthalmologic examination and SD-OCT were performed at the first visit. The patients were followed up weekly, and the SD-OCT images were taken over the lesion at each visit for 6 weeks. The characteristics of the active retinochoroiditis focus at the first visit were determined, and the infiltrate thicknesses at all visits were analyzed. RESULTS: A statistically significant BCVA difference was observed at the first visit and at the last visit 6 weeks later (p < 0.01). The first week after treatment showed a significant decrease in infiltrate thickness (113.904 ± 86.001 µm). In the following weeks, this decrease continued more softly. The thickness change at 6 weeks was significantly reduced (16.095 ± 14.784 µm) compared with the previous ones. Weekly infitrate thickness changes were compared among themselves; a statistically significant difference was found between the 1st and 2nd weeks and the 5th and 6th weeks (p = 0.035 and p = 0.007, respectively). Detached posterior vitreous in 71% (15/21) and increased posterior vitreous thickness in 76% (16/21) of active lesion were detected. All patients had 100% (21/21) increased retinal reflectivity and disorganized retinal layers, and choroidal hypo-reflectivity was observed in 86% (18/21). CONCLUSION: SD-OCT is a useful imaging modality in the diagnosis and follow-up of ocular toxoplasmosis cases. Serial thickness measurements of toxoplasma retinochoroiditis lesions may help confirm our diagnosis and determine the need for treatment.

Optical Coherence Tomography Angiography Findings in Ocular Toxoplasmosis with Multiple Recurrences.

Ocular toxoplasmosis is the most common cause of posterior uveitis that is caused by Toxoplasma gondii infection. Humans can be infected congenitally or postnatally. The typical lesion of ocular toxoplasmosis is focal necrotizing retinitis with overlying vitritis, which lead to hyperpigmented retinochoroidal scar at resolution of lesion. Macula involvement can cause substantial visual impairment. The high incidence of disease reactivation may lead to greater risk of vision loss. Optical coherence tomography angiography (OCTA) is a non-invasive imaging method to visualize the vascular and density perfusion of the retina and choroid, which cannot be obtained by conventional Optical Coherence Tomography (OCT). In this case report, we present two cases of active ocular toxoplasmosis with multiple recurrences to study pathological changes in retinal and choroidal microvasculature. The findings reveal the involvement of all of the retinal layers in the choroid, with distinct changes in the deep retinal layer.

Recurrence of Ocular Toxoplasmosis after Vitrectomy: Case Report and Review.

PURPOSE: The purpose of this study is to report one case of ocular toxoplasmosis (OT) recurrence after vitrectomy and review the scientific basis about it. CASE REPORT: A 58-year-old male patient with previous OT, properly treated, underwent vitrectomy due to macular hole. During follow-up, patient evolved with recurrence of the OT. After 1 year, patient presents visual acuity of 20/200 and extensive macular scar. CONCLUSION: There is no consensus on using perioperative antiparasitic therapy aiming recurrence prophylaxis. Studies with better statistical design are necessary to evaluate the recurrence risk after ocular surgeries and the possible recommendation of prophylaxis, especially in countries where the strains are more virulent and the recurrence more common.

Association of Proton Pump Inhibitor/Histamine-2 Blocker Use and Ocular Toxoplasmosis: Findings from a Large US National Database.

OBJECTIVE: To test the hypothesis that the use of proton pump inhibitors (PPIs) is associated with an increased risk of being diagnosed with toxoplasmic retinochoroiditis. DESIGN: Retrospective, matched case-control study using data from 2000 to 2020. PARTICIPANTS: Patients with ocular toxoplasmosis and controls were matched 5:1 for age, sex, and race, with the eligibility date ± 3 months from the index date of exposed match. Patients aged < 18 years with congenital toxoplasmosis, having < 2 years in the insurance plan before the index date, and without ≥ 1 visit to an eyecare provider before the index date were excluded from the study. METHODS: Patients with ocular toxoplasmosis were identified using the International Classification of Diseases, Ninth Revision and International Classification of Diseases, Tenth Revision codes, and PPI use or diseases highly associated with PPIs were identified using national drug codes from an administrative medical claims database. MAIN OUTCOME MEASURES: The primary outcome was defined as having a prescription for a PPI or histamine-2 (H2) blocker. Multivariable logistic regression analyses were performed, controlling for demographic and systemic health variables. RESULTS: A total of 4069 cases and 19 177 controls met the eligibility criteria. Of the 4069 patients with ocular toxoplasmosis, 989 (24.3%) were on PPI/H2 blockers compared with 3763 of 19 177 (19.2%) controls. The adjusted logistic regression model demonstrated 1.28 greater odds of PPI/H2 blocker use in cases of ocular toxoplasmosis than matched controls (95% confidence interval, 1.17-1.40; P < 0.001). CONCLUSIONS: Proton pump inhibitor/H2 blocker exposure was associated with an increased risk of being diagnosed with ocular toxoplasmosis, corroborating findings from a prior case series. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found after the references.

Swept-source Optical Coherence Tomography Angiography in Active and Scarred Toxoplasmic Retinochoroiditis.

PURPOSE: To describe optical coherence tomography angiography (OCTA) findings in eyes with active and scarred toxoplasmic retinochoroiditis. METHODS: OCTA scans in active (25 eyes) and scarred (17 eyes) retinochoroiditis were retrospectively reviewed. RESULTS: In active lesions, OCTA findings included a non-detectable flow signal area in retinal vascular plexuses and choriocapillaris in all 25 eyes (100%), an abnormal intraretinal vascular process in 2 eyes (8%), and an associated area of retinal flow deficit secondary to branch retinal artery occlusion in one eye (4%). In scarred lesions, OCTA findings included a flow deficit area in retinal vascular plexuses and choriocapillaris in all 17 eyes (100%), a visibility of larger deeper choroidal vessels at the level of choriocapillaris in 9 eyes (53%), and a well-defined intraretinal vascular network in one eye (5.9%). Peripapillary scars were associated on OCTA with wedge-shaped loss of radial peripapillary capillaries with corresponding localized retinal nerve fiber layer defect and visual field loss. CONCLUSION: OCTA allows to non-invasively detect retinal and choroidal vascular changes in active and scarred toxoplasmic retinochoroiditis.

Primary ocular toxoplasmosis secondary to venison consumption.

Purpose: To describe primary ocular toxoplasmosis infection related to ingestion of undercooked venison. Observations: This single site, retrospective case series reviewed 4 patients with primary ocular toxoplasmosis that was acquired by ingesting undercooked venison. De-identified data was collected regarding baseline patient characteristics including age, sex, past medical and ocular history, onset of symptoms, visual acuity (VA), response to treatment, and workup. All patients with acquired toxoplasmosis had similar chronology of systemic and ocular symptoms. Exposure occurred in October or November and systemic symptoms developed within 2 weeks, followed by ocular symptoms an average of 2.6 months later. Average age at onset was 56 ± 13 (age ± SD) years old and all were male. Average initial and final VA were 20/50 and 20/50, respectively. Positive anti-toxoplasma IgM and IgG serologies were found in all cases. All patients were treated with trimethoprim/sulfamethoxazole and achieved rapid improvement. Complications occurred in 50% of cases and included epiretinal membrane, cystoid macular edema, vitreoretinal traction, and neovascularization. Conclusions and importance: Consumption of undercooked venison is a source of primary ocular toxoplasmosis even in immunocompetent hosts and has a clear chronology. A presentation of retinochoroiditis during the winter months should prompt questioning for exposure to wild game.

Ocular Toxoplasmosis.

INTRODUCTION: Ocular toxoplasmosis is the leading cause of posterior uveitis worldwide, affecting individuals acrossdifferent age groups. The key to reducing vision loss includes prompt diagnosis and treatment. However, despite the prevalence of ocular toxoplasmosis, there has been little consensus regarding its pathophysiology,clinical features, diagnosis, and especially management. METHODS: The data sources were literature reviews, including Pub Med and Medline databases. Search terms included toxoplasmosis, retinitis, vasculitis, vitritis, uveitis alone or in combination with, serum, aqueous, vitreous eye, ocular and review. RESULTS: In this review paper, we have sought to provide an overview of the pathophysiology, epidemiology, and clinical features of the disease, both based on current literature and our own clinical experience. We have also discussed the use of serology, ocular fluid, and ophthalmic investigations that could further facilitate the diagnosis of ocular toxoplasmosis.Different management strategies have been reported worldwide, including newer approaches such as local therapy. CONCLUSION: A better understanding of critical aspects of ocular toxoplasmosis will hopefully lead to reduced morbidity, including blindness associated with this condition.

ATYPICAL FORMS OF EYE TOXOPLASMOSIS IN CHILDHOOD. CASE REPORTS.

AIM: To present an outline of acquired atypical forms of ocular toxoplasmosis (OT) in childhood, with reference to the 100th anniversary of the discovery of this etiology by Professor Janků from Czechoslovakia, who was first to describe the clinical congenital picture of OT characterised by macular scar. MATERIAL AND METHODS: Symptoms of intraocular bilateral neuritis appeared in a 6-year-old girl, with visual acuity (VA) bilaterally 0.1. Toxoplasmic etiology was demonstrated in laboratory tests, and the patient was immunocompetent. Following treatment with macrolide antibiotic and parabulbar application of corticosteroid, the condition was normalised stably at VA 1.0 in both eyes. Bilateral retinal vasculitis was determined in an 8-year-old boy, with VA of 0.25 in the right eye and 0.25 in the left, with a medical history of strabismus detected after suffering from varicella. The examination for toxoplasmosis was negative, but pronounced general hypogammaglobulinaemia classes IgG, IgM and IgA was detected. Immunosuppressive and immunomodulatory therapy did not produce the desired effect, and the condition progressed to retinochoroiditis. Due to blindness and dolorous glaucoma, enucleation of the right eye was performed at the age of 15 years. Histologically toxoplasmic cysts with bradyzoites were detected, a subsequent laboratory test demonstrated toxoplasmic etiology upon a background of persistent regressing hypogammaglobulinaemia. General anti-toxoplasma and subsequent immunosuppressive treatment did not produce the desired effect, and at the age of 22 years the patient lost his sight also in the left eye. CONCLUSION: Atypical form of OT intraocular neuritis in an immunocompetent patient had a favourable course, whereas retinal vasculitis with retinochoroiditis in a temporarily immunocompromised patient ended in bilateral blindness.

Long-Term Outcomes in Children with Congenital Toxoplasmosis-A Systematic Review.

Even in the absence of manifestations at birth, children with congenital toxoplasmosis (CT) may develop serious long-term sequelae later in life. This systematic review aims to present the current state of knowledge to base an informed decision on how to optimally manage these pregnancies and children. For this, a systematic literature search was performed on 28 July 2022 in PubMed, CENTRAL, ClinicalTrials.gov, Google Scholar and Scopus to identify all prospective and retrospective studies on congenital toxoplasmosis and its long-term outcomes that were evaluated by the authors. We included 31 research papers from several countries. Virulent parasite strains, low socioeconomic status and any delay of treatment seem to contribute to a worse outcome, whereas an early diagnosis of CT as a consequence of prenatal screening may be beneficial. The rate of ocular lesions in treated children increases over time to 30% in European and over 70% in South American children and can be considerably reduced by early treatment in the first year of life. After treatment, new neurological manifestations are not reported, while ocular recurrences are observed in more than 50% of patients, with a mild to moderate impact on quality of life in European cohorts when compared to a significantly reduced quality of life in the more severely affected South American children. Though CT is rare and less severe in Europe when compared with South America, antenatal screening is the only effective way to diagnose and treat affected individuals at the earliest possible time in order to reduce the burden of disease and achieve satisfying outcomes.

Recurrent and De Novo Toxoplasmosis Retinochoroiditis following Coronavirus Disease 2019 Infection or Vaccination.

This study reports three cases of toxoplasmosis retinochoroiditis following coronavirus disease 2019 (COVID-19) infection or vaccination from the national Canadian COVID-19 Eye Registry between December 2020 and September 2021. A 56-year-old male presented 15 days after a positive COVID-19 test with toxoplasmosis retinochoroiditis. He later relapsed 8 days following a first Pfizer-BioNTech vaccine dose. Two patients presented with toxoplasmosis retinochoroiditis following COVID-19 vaccination: A 58-year-old female presenting 4 days following a first Pfizer-BioNTech vaccine dose with anterior uveitis and a posterior pole lesion discovered 3 months later and a 39-year-old female presenting 17 days after a first Moderna vaccine dose. Resolution was achieved with oral clindamycin, oral trimethoprim/sulfamethoxazole, and topical prednisolone acetate 1%. Patients were offered prophylactic trimethoprim/sulfamethoxazole for subsequent doses without relapse. Following COVID-19 infection or vaccination, patients may be at risk for toxoplasmosis retinochoroiditis. Prophylactic antibiotics for future doses may be offered to patients with known ocular toxoplasmosis to prevent recurrence.

Clinical and imaging characteristics of outer retinal folds in eyes with retinitis.

Purpose: To describe clinical and imaging characteristics of the outer retinal folds (ORF) in cases of retinitis, retinochoroiditis, and chorioretinitis. Methods: Retrospective review of retinitis cases with presence of ORFs either at presentation or during follow up. Results: ORFs were seen adjacent to retinitis lesions in 16 eyes of 14 cases (retinitis post-febrile illness n = 10, toxoplasma retinochoroiditis n = 2, fungal chorioretinitis n = 2) either at presentation (n = 2) or during follow up (n = 14). Optical coherence tomography (OCT) appearance was outer retinal vertical stout lesions involving ellipsoid, external limiting membrane, and outer nuclear layer. All the cases had a presence of past or concurrent subretinal fluid and/or subretinal hyperreflective material when ORF was seen. ORF resolved with variable outer retinal atrophy over a mean period of 2.86 months. Conclusion: ORF is observed in cases of retinitis with subretinal fluid either at presentation or during resolution. It is not specific to any etiological disease. Differentiation of this sign from vertical outer retinal stripes in viral retinitis on OCT is important to avoid misinterpretation.