Pathophysiological Aspects of Ocular Toxoplasmosis: Host-parasite Interactions.

PURPOSE: This review aims to present the state of the art to understand the pathophysiology of ocular toxoplasmosis (OT), providing further foundations that would help to improve the future treatment and prognosis of this potentially blinding disease. METHODS: A thorough literature search was performed in PubMed database. An additional search was made in Google Scholar to complete the collected items. RESULTS: Toxoplasma gondii ocular infection is one of the most frequent causes of posterior uveitis. Despite the ocular barriers, the parasite reaches the eye through different mechanisms. Once inside, it remains encysted livelong within the retina, and recurrences cannot be completely avoided. The complexity of host-parasite interactions, leading to the success of this parasite, encompasses host factors such as genetic predisposition, immune status, and age; and parasite factors such as strain diversity, virulence, phylogenetic origin, and geographical distribution. These factors influence the clinical presentation, course, and progression of the disease. Additional elements, such as pregnancy, eating behavior, and environmental, social, and cultural factors may also contribute to this complex balance. CONCLUSIONS: The host-parasite interaction in OT is a complex and multifactorial relationship, with the parasite always on the driving edge of the game. There are still multiple incompletely understood fields to be investigated. Future research would permit further insight into the immune-biology of the parasite and recognition of the host-parasite interplay to improve the diagnostic and management performance.

Ocular toxoplasmosis: a review of the current diagnostic and therapeutic approaches.

PURPOSE: This review aims to summarize the current knowledge concerning the clinical features, diagnostic work-up and therapeutic approach of ocular toxoplasmosis focusing mainly on the postnatally acquired form of the disease. METHODS: A meticulous literature search was performed in the PubMed database. A supplementary search was made in Google Scholar to complete the collected items. RESULTS: Ocular toxoplasmosis is one of the most frequent infectious etiologies of posterior uveitis. It typically presents with retinochoroiditis. Setting an accurate diagnosis depends to a considerable degree on detecting characteristic clinical characteristics. In addition to the evaluation of clinical features, the diagnosis of toxoplasmosis relies at a large degree on serologic testing. The detection of the parasite DNA in the aqueous or vitreous humor can provide evidence for a definitive diagnosis. The current mainstay for the treatment, if necessary, is the use of oral antibiotic with systemic corticosteroids. Recent evidence suggests other therapeutic approaches, such as intravitreal antibiotics can be used. CONCLUSION: Recent developments in the diagnostic and therapeutic approach have contributed to preventing or limiting vision loss of patients suffering from ocular toxoplasmosis. Further studies are required to provide a better understanding of epidemiology, pathogenesis, diagnosis, and treatment with a significant impact on the management of this challenging clinical entity.

Spirochetal uveitis: Spectrum of clinical manifestations, diagnostic and therapeutic approach, final outcome and epidemiological data.

PURPOSE: Analysis of cases with spirochetal uveitis related to spirochetes in a tertiary referral academic center. METHODS: Retrospective study of patients diagnosed with uveitis attributed to Treponema pallidum, Leptospira spp. and Borrelia burgdorferi from June 1991 until December 2019. RESULTS: A total of 57 cases of spirochetal uveitis (22 patients with T. pallidum, 26 with Leptospira spp., and 9 with B. burgdorferi) that consisted 1% of the overall number of uveitics were recorded. All these cases presented with a wide spectrum of clinical presentations (anterior uveitis, posterior uveitis, panuveitis, vasculitis, papillitis, and in some rare cases concomitant posterior scleritis). The treatment included mainly penicillin or doxycycline, while corticosteroids were administered systematically in some cases with Borrelia or Leptospira infection. The final visual outcome was favorable (> 6/10 in Snellen visual acuity) in approximately 76% of our patients. CONCLUSION: Despite being rare, spirochetal uveitis can be detrimental for the vision and must always be included in the differential diagnosis.

Four common diseases causing sudden blindness or death in the eye emergency department.

Neuro-ophthalmological emergency disorders typically present with symptoms of visual loss, diplopia, ocular motility impairment or anisocoria. The ocular manifestations of these disorders are sometimes indicative of a more serious global neurology disease rather than an isolated ocular disease. The aim of this review is to highlight four important neuro-ophthalmological emergency disorders that must not be missed by an ophthalmologist. These include acute painful Horner's syndrome, painful cranial nerve III palsy, giant cell arteritis and transient ischaemic attack with amaurosis fugax. The delayed diagnosis of these clinical entities puts the patient at risk of blindness or death. Therefore, prompt diagnosis and management of these conditions are essential. This can be acquired from understanding the main signs and symptoms of the disease presentation together with a high index of suspicion while working at a busy eye emergency department.

Bartonella henselae- and quintana-associated uveitis: a case series and approach of a potentially severe disease with a broad spectrum of ocular manifestations.

PURPOSE: To evaluate the clinical manifestations of intraocular inflammation associated with Bartonella infection and describe the assessment and management of patients with cat-scratch disease (CSD). METHODS: This is a retrospective review of the clinical records of patients diagnosed with Bartonella henselae and Bartonella quintana intraocular inflammation from 2011 to 2018 in the Department of Ocular Inflammations and Infections of the University Eye Clinic of Ioannina (Greece). An analysis of the current literature concerning Bartonella-related intraocular infections was also carried out. RESULTS: This is a retrospective study of 13 patients (7 males and 6 females) with a mean age of 39.2 years that were diagnosed with unilateral intraocular inflammation, except one case with bilateral affection, attributed to Bartonella (either henselae or quintana). Twelve (12) patients (92.3%) had a positive history of traumatic cat contact. The main ocular clinical findings with regard to the type of uveitis included neuroretinitis in 5 eyes (38.5%), vasculitis in 3 eyes (23.1%), iridocyclitis in 2 eyes (15.4%), intermediate uveitis in 2 eyes (15.4%), posterior uveitis in 1 eye (7.7%), panuveitis in 2 eyes (15.4%), retinochoroiditis in 2 eyes (15.4%), vitritis in 1 eye (7.7%), peripheral choroidal granuloma in 1 eye (7.7%). Immunoglobulin (Ig) G was positive in all cases. All patients were treated with antibiotics (mainly rifampicin, doxycycline and azithromycin). The visual acuity was noted to be improved in all patients after treatment, but some of them experienced disturbing complications. CONCLUSION: CSD may manifest with various ocular pathological findings. Taking into consideration the increasing frequency of infections by B. henselae and B. quintana, clinicians should always incorporate CSD in the differential diagnosis of such presentations of uveitis. Educating vulnerable groups (children, immunosuppressed, etc.) and also general population, the appropriate preventing measures can contribute in limiting the risk of infection.

New Therapeutic Perceptions in a Patient with Complicated Herpes Simplex Virus 1 Keratitis: A Case Report and Review of the Literature.

BACKGROUND Keratitis caused by herpes simplex virus (HSV) can have detrimental effects on the cornea leading to loss of vision. Modern therapies can contribute to the prevention of anatomical and functional damage. CASE REPORT An 80-year-old male with complicated HSV-1 keratitis of the left eye (confirmed diagnosis after microbiological investigation) presented three months after antiviral treatment with corneal blurring, severe epitheliopathy, thinning of the stroma, and neovascularization. At the time he was referred, the visual acuity of his left eye was very low, as he could only count fingers at a one-foot distance. He was initially started on oral acyclovir (800 mg once daily) and topical poly-carboxymethyl glucose sulfate; afterwards he underwent amniotic membrane (AM) transplantation and localized treatment with anti-VEGF factors. One month after the AM transplantation there was an obvious improvement of the corneal surface. Ophthalmic suspension of cyclosporine-A 1% was also added to his treatment. After three months, a transplantation of stem cells (deriving from the sclerocorneal junction of his right eye) was carried out at the sclerocorneal junction, as the corneal damage and neovascularization was more severe at this anatomical area. Four months after the last surgery, his visual acuity was 1/10 (note, he had a history of an old vascular episode) and the cornea was sufficiently clear with no signs of epitheliopathy and almost complete subsidence of the neovascularization. CONCLUSIONS Transplantation of AM and stem cells in combination with anti-VEGF factors and topical administration of cyclosporine-A 1% and poly-carboxymethyl glucose sulfate (a regenerative factor of corneal matrix) contributed substantially in the management of herpetic keratitis complications.

Tuberculous Posterior Sclero-Uveitis with Features of Vogt-Koyanagi-Harada Uveitis: An Unusual Case.

BACKGROUND Ocular tuberculosis (TB) is a clinical entity that presents with a wide range of clinical manifestations. It is regarded as an extremely challenging condition from the point of view of diagnostic approach and calls for early diagnosis and prompt treatment, as it can potentially lead to blindness. CASE REPORT This is a case report of a 32-year-old male from southern India who has been living and working in Greece over the last 10 years and presented with 2-week history of pain and progressive visual impairment of his left eye. He underwent a thorough clinical ophthalmological examination and imaging of the fundus, and the findings were consistent with uveitis. However, the manifestations of the inflammation were complicated as they included features that could be attributed mainly to Vogt-Koyanagi-Harada (VKH) disease and tuberculous serpiginous-like uveitis. Therefore, a systemic evaluation, together with specific laboratory and paraclinical investigations, were carried out to define the etiology of the inflammation and develop an optimal therapeutic plan. Taking into account specific findings from the chest imaging, a positive purified protein derivative (PPD) skin test, and sputum cultures positive for Mycobacterium tuberculosis (MTB), we set a diagnosis of posterior sclero-uveitis and started our patient on anti-tuberculous treatment. CONCLUSIONS This case reveals an atypical manifestation of tuberculous sclero-uveitis imitating Vogt-Koyanagi-Harada disease together with a few characteristics of serpiginous-like tuberculous uveitis, emphasizing the fact that tuberculosis should always be included in the differential diagnosis of uveitis when there is no obvious underlying disease.