Update on pathology of ocular parasitic disease

Parasites are a group of eukaryotic organisms that may be free-living or form a symbiotic or parasitic relationship with the hosts. Consisting of over 800,000 recognized species, parasites may be unicellular (Protozoa) or multicellular (helminths and arthropods). The association of parasites with human population started long before the emergence of civilization. Parasitic zoonotic diseases are prevalent worldwide including India. Appropriate epidemiological data are lacking on existing zoonotic parasitic diseases, and newer diseases are emerging in our scenario. Systemic diseases such as cysticercosis, paragonimiasis, hydatidosis, and toxoplasmosis are fairly common. Acquired Toxoplasma infections are rising in immune-deficient individuals. Amongst the ocular parasitic diseases, various protozoas such as Cystoidea, trematodes, tissue flagellates, sporozoas etc. affect humans in general and eyes in particular, in different parts of the world. These zoonoses seem to be a real health related problem globally. Recent intensification of research throughout the world has led to specialization in biological fields, creating a conducive situation for researchers interested in this subject. The basics of parasitology lie in morphology, pathology, and with recent updates in molecular parasitology, the scope has extended further. The current review is to address the recent update in ophthalmic parasites with special reference to pathology and give a glimpse of further research in this field

Reaction of a Copper(II)–Nitrosyl Complex with Hydrogen Peroxide: Phenol Ring Nitration through a Putative Peroxynitrite Intermediate

Copper­(II) complex, <b>1</b>, with the histidine-derived ligand <b>L</b> (<b>L</b> = methyl 2-(2-hydroxybenzylamino)-3-(1<i>H</i>-imidazol-5-yl)­propanoate) has been synthesized and characterized. Single-crystal structure determination reveals a diphenolato-bridged dicopper­(II) core in <b>1</b>. Addition of ^•NO to an acetonitrile solution of <b>1</b> affords the corresponding mononuclear copper­(II)–nitrosyl complex, <b>2</b>. In the presence of H₂O₂, <b>2</b> results in formation of the corresponding copper­(I)–peroxynitrite. Formation of peroxynitrite (⁻OONO) intermediate is evident from its characteristic phenol ring nitration reaction which resembles the tyrosine nitration in biological systems. Further, isolation of nitrate (NO₃^–) as the decomposition product from <b>2</b> at room temperature also supports the involvement of ^–OONO intermediate

An interesting case of angiogenesis in cavernous hemangioma

Cavernous hemangioma is the most common orbital tumor in adult. There is lot of literatures for clinicopathological features of this tumor. These tumors had been studied for the model of angiogenesis in many of the experimental setups. We present a case of 34-year-old male with this tumor in the left eye with computerized tomography evidence. Postsurgical laboratory findings gave interesting evidence of tumor angiogenesis with tumor endothelial cells and sprouting of the small vessels endothelial cells. Podosome rosette could be conceptualized from the characteristic patterns seen in the tumor

Reaction of a Copper(II)–Nitrosyl Complex with Hydrogen Peroxide: Phenol Ring Nitration through a Putative Peroxynitrite Intermediate

Copper­(II) complex, <b>1</b>, with the histidine-derived ligand <b>L</b> (<b>L</b> = methyl 2-(2-hydroxybenzylamino)-3-(1<i>H</i>-imidazol-5-yl)­propanoate) has been synthesized and characterized. Single-crystal structure determination reveals a diphenolato-bridged dicopper­(II) core in <b>1</b>. Addition of ^•NO to an acetonitrile solution of <b>1</b> affords the corresponding mononuclear copper­(II)–nitrosyl complex, <b>2</b>. In the presence of H₂O₂, <b>2</b> results in formation of the corresponding copper­(I)–peroxynitrite. Formation of peroxynitrite (⁻OONO) intermediate is evident from its characteristic phenol ring nitration reaction which resembles the tyrosine nitration in biological systems. Further, isolation of nitrate (NO₃^–) as the decomposition product from <b>2</b> at room temperature also supports the involvement of ^–OONO intermediate

Histopathology of Pigment dispersion syndrome and glaucoma

Pigment dispersion syndrome (PDS) can have varied manifestations. Anterior and posterior segment involvement by dispersed pigments was documented in gross pathology and by staining under microscopy. Pigmentary changes in the sclera, cornea, anterior chamber, iris, trabecular meshwork, lens, and retinal pigment epithelium and optic nerve findings were consistent with PDS. External scleral and vitreous pigmentation has never been reported before in the scientific literature. Retinal pigment degeneration and granule dispersion were seen throughout the retina which could be a contributing factor in the etiology of PDS

Molecular pathologic interpretation of new retinoblastoma rosettes

Newly described retinoblastoma (RB) rosettes have various kinds of pathological significance. Some of their characteristics have been revealed in this immunohistochemistry study. Five paraffin-embedded eyeballs with RB and new rosettes were studied for neuron-specific enolase (NSE), p53, p16, BAX, c-Myc, glial fibrillary acidic protein, synaptophysin, and chromogranin. They were compared and interpreted using control specimens. NSE, P53, and P16 were significantly expressed in the cells of the new rosettes. The presence of new RB rosettes that mostly have histopathological high-risk factors and p53 positivity may be a strong marker of poor prognosis of RB

A rare case of anterior chamber dirofilariasis

We report a rare case of anterior chamber live dirofilariasis presenting as anterior uveitis. A 60-year-old man presented with dimness of vision in the right eye for 1 month. Vision recorded was 6/18 P, N 18 in the right eye. Slit lamp examination of the right eye revealed anterior uveitis with a moving nemathelminthes. The worm was removed live from the anterior chamber under local anesthesia with assisted methyl cellulose delivery and post-operatively, the worm was examined directly under light microscope. Morphometric measurement showed length of the worm was 6.061 mm. A thin, pale, slender worm was diagnosed as immature female Dirofilaria repens and was documented completely. Patient had made an excellent recovery of vision and intraocular inflammation after the surgical removal of the worm. Intraocular infection of dirofilaria is a rare presentation and successful surgical removal of the worm resulted in complete recovery of uveitis and visual status in the affected eye

Immunohistochemistry on pattern of ocular & adnexal tumours in a tertiary eye care centre of Northeast India

Background & objectives: Ocular and adnexal tumours are important causes of morbidity in India and globally. Immunohistochemistry (IHC) is a vital molecular pathology tool, which helps to diagnose a tumour with more accuracy. The present study was undertaken to document the profile of ocular and adnexal tumour with IHC at a tertiary eye care center in Northeast India. Methods: This was a prospective and laboratory-based study. Histopathological and IHC study of the ocular and adnexal tumour was carried out from 2012 to 2014. Selection of pathological cases was made on the result of the histological diagnosis. All samples were subjected to IHC using kits for different antibodies as per indications. Results: In total, 645 tumours were included in our study, with 449 benign conditions and 196 were malignant tumours. Total IHCs were done in 87 tumours and 238 of antibodies were used. Non-Hodgkin's lymphomas (B-cell, low-to-intermediate type and mucosal-associated lymphoid tumours) were the most common tumor. Interpretation & conclusions: Clinical utility of the IHCs in different ophthalmic tumours can enable pathologists to make an accurate diagnosis and thus help in the overall management of the patient care. IHC may be carried out using various methods and some of the methods practiced are time consuming and tedious. In this study, kit methods were used which were found to be simpler and less time-consuming

Systemic diffuse large B-cell lymphoma masquerading as neovascular glaucoma

We describe a case of spontaneous hyphema associated with anterior uveitis presents in a 69-year old female as the prominent sign of the intraocular spread of systemic diffuse large B-cell lymphoma (DLBCL). She had a history of diabetes and initially misdiagnosed as neovascular glaucoma. Clinical history of systemic lymphoma, characteristic findings on B-scan ultrasonography and magnetic resonance imaging scan, and identification of atypical lymphoid cells in aqueous sample established the diagnosis of intraocular metastasis of systemic DLBCL. Therefore, this report highlights that life-threatening malignant systemic lymphoma may masquerade as anterior segment ocular inflammation or neovascular glaucoma