A zebrafish model for ocular tuberculosis.

Ocular tuberculosis (TB) commonly causes severe inflammation and vision loss in TB-endemic countries. The mechanism by which tuberculous infection becomes established in the eye is poorly understood. We have developed the zebrafish larva infected with Mycobacterium marinum as a model to study the early pathogenesis of ocular TB. We find that hematogenous bacterial seeding of the eye occurs despite a functional blood retinal barrier. Prototypical early granulomas form in response to bacteria in the eye. These granulomas involve the retinal vasculature and retinal pigment epithelium-choroid complex which are characteristic locations for human ocular TB. We find that peripheral blood monocytes are recruited to the nascent ocular granuloma further suggesting that the immune privileged nature of the eye is breached by this inflammatory focus

Changing Clinical Presentation, Current Knowledge-Attitude-Practice, and Current Vision Related Quality of Life in Self-Reported Type 2 Diabetes Patients with Retinopathy in Eastern India: The LVPEI Eye and Diabetes Study

Purpose. To document the changing clinical presentation of diabetic retinopathy (DR) over a decade, the current knowledge-attitude-practice (KAP) of known type 2 diabetes mellitus (DM) patients, and the current vision related quality of life (VR-QOL) of patients with DR in a tertiary eye care center in Eastern India. Methods. Two hundred and forty patients with known type-2 DM were evaluated. The evaluation included status of DR (n=240), KAP (n=232), and VR-QOL (n=75). International classification of DR was used in the study. The DR status was compared with another cohort (n=472) examined a decade earlier, in year 2001. The KAP-25 questions were designed after literature review. The National Eye Institute Visual Function Questionnaire (NEI-VFQ; including optional items) was validated by Rasch analysis. Both KAP and VR-QOL were analyzed according to degree of DR, duration of known DM, and educational qualification. Results. Average age of the current cohort (n=240) was 57.16 ± 9.03 years; there were 205 (85.4%) male patients and 143 (59.6%) patients had received less than graduate qualification. The mean duration of DM since diagnosis was 10 ± 7.8 months (range 8 months to 30 years); 118 (49.16%) patients had DR. In a decade time, 2001 to 2011, there was a change of retinopathy status at presentation (more often nonproliferative diabetic retinopathy, NPDR). One-third of NPDR patients had poor vision and half of them were hypertensive. KAP was better in patients with higher education and those having DR. VFQ score was higher in better seeing patients. Conclusion. Patients currently presenting at earlier stage of retinopathy are probably related to poor vision. Early detection and treatment of DR is likely to preserve and/or improve vision

Steroid-responsive serous retinal detachment in undetected chronic lymphocytic leukemia

A 69-year-old diabetic man, treated intermittently with oral and periocular corticosteroids for suspected left eye choroiditis for past one year, presented with decreased vision in left eye. We noted best-corrected visual acuity (BCVA) of 20/35 and 20/30 in right and left eyes, respectively. Right lens was cataractous and left pseudophakic. Right fundus was normal while left showed shallow serous detachment around optic disc with underlying focal choroidal lesions. Blood investigations revealed markedly raised leukocyte count with marked lymphocytosis. Bone marrow cytology confirmed B-cell chronic lymphocytic leukemia. The patient′s ocular and systemic condition resolved with rituximab and bendamustine chemotherapy

A zebrafish model for ocular tuberculosis.

Ocular tuberculosis (TB) commonly causes severe inflammation and vision loss in TB-endemic countries. The mechanism by which tuberculous infection becomes established in the eye is poorly understood. We have developed the zebrafish larva infected with Mycobacterium marinum as a model to study the early pathogenesis of ocular TB. We find that hematogenous bacterial seeding of the eye occurs despite a functional blood retinal barrier. Prototypical early granulomas form in response to bacteria in the eye. These granulomas involve the retinal vasculature and retinal pigment epithelium-choroid complex which are characteristic locations for human ocular TB. We find that peripheral blood monocytes are recruited to the nascent ocular granuloma further suggesting that the immune privileged nature of the eye is breached by this inflammatory focus

Animal models of ocular tuberculosis: implications for diagnosis and treatment

The pathogenesis of ocular tuberculosis (TB) has remained unclear due to the challenges of performing mechanistic studies on clinical samples. Animal models have the potential to bridge these gaps by providing information about ocular dissemination and localization of mycobacteria, innate and adaptive immune response, and granuloma formation in the eye. Here, we critically review various animal models of ocular TB from the early 20th century to date and derive novel insights into pathogenesis of ocular TB that have direct implications on the diagnosis and treatment of this disease. Future directions on experimental approaches to understanding pathogenesis of ocular TB are also discussed