Occlusion of retinal capillaries caused by glial cell proliferation in chronic ocular inflammation.

The inner blood-retinal barrier is a gliovascular unit in which glial cells surround capillary endothelial cells and regulate retinal capillaries by paracrine interactions. During chronic ocular inflammation, microvascular complications can give rise to vascular proliferative lesions, which compromise visual acuity. This pathologic remodelling caused by proliferating Müller cells determines occlusion of retinal capillaries. The aim of the present study was to identify qualitative and quantitative alterations in the retinal capillaries in patients with post-traumatic chronic ocular inflammation or post-thrombotic vascular glaucoma. Moreover, we investigated the potential role of vascular endothelial growth factor (VEGF) and pro-inflammatory cytokines in retinal inflammation. Our electron microscopy findings demonstrated that during chronic ocular inflammation, thickening of the basement membrane, loss of pericytes and endothelial cells and proliferation of Müller cells occur with irreversible occlusion of retinal capillaries. Angiogenesis takes place as part of a regenerative reaction that results in fibrosis. We believe that VEGF and pro-inflammatory cytokines may be potential therapeutic targets in the treatment of this disease although further studies are required to confirm these findings.

Immunohistochemical profile of VEGF, TGF-ß and PGE2 in human pterygium and normal conjunctiva: experimental study and review of the literature.

Human pterygium is made up of chronic proliferative fibro-vascular tissue growing on the ocular surface. This disease exhibits both degenerative and hyperplastic properties. Some fibroangiogenic factors have recently been shown to play a potential role in fibrovascular diseases via the angiogenesis process. The aim of this study is to evaluate VEGF, TGF-ß and PGE2 expression in the epithelial, endothelial and stromal cells of human pterygium and normal conjunctiva in order to determine whether these factors participate in the development of pterygium. Ten specimens from patients with pterygium and two normal conjunctivas (cadavers) were analyzed by immunohistochemistry using specific antibodies against these growth factors. The technique used was ABC/HRP (Avidin complexed with biotinylated peroxidase). Immunoreactivity of VEGF was significantly increased in the epithelium, vascular endothelium and stromal cells in primary pterygium as compared with normal conjunctiva. A moderate expression of TGF-ß in the pterygium was observed in the epithelial and stromal layers. On the contrary, immunolabeling of this growth factor in the human normal conjunctiva was weak. PGE2 was strongly expressed in the epithelium of patients with pterygium, as in control conjunctival tissues, and the immunolabeling was moderate in the stroma from the same patients. Our results suggest that these growth factors may contribute to the progression of primary pterygium by increasing angiogenesis, thus leading to the formation of new blood vessels from the pre-existing vasculature. We conclude that VEGF, TGF-ß and PGE2 may be potential therapeutic targets in the treatment of this disease although proof of this evidence requires further studies.

Idiopathic juxtafoveal retinal telangiectasis and retinal macroaneurysm treated with indocyanine green dye-enhanced photocoagulation.

This case report presents the use of indocyanine green dye-enhanced photocoagulation (ICG-DEP) for the treatment of idiopathic juxtafoveal retinal telangiectasis and a retinal macroaneurysm. A 35-year-old male with 20/20 vision had been followed for 5 years for a retinal macroaneurysm with retinal telangiectasis outside the macular area. He then presented with a recently decreased vision in his right. He had macular edema with a new area of idiopathic juxtafoveal retinal telangiectasis. After 4 focal argon laser treatments, angiographic closure of the lesions was not obtained and the retinal edema remained. After 3 sessions of ICG-DEP, the lesions were closed and the edema absorbed. The 810 nm infrared laser with ICG-DEP should be considered for the treatment of idiopathic juxtafoveal retinal telangiectasis and retinal macroaneurysms. In this case the procedure appears to be safe and well tolerated. It may allow for more direct energy absorption than that of the argon laser to these types of retinal lesions with better tissue closure.

Optic nerve aplasia associated with macular 'atypical colobomà'.

A 12-year-old patient presenting with absence of the optic disc and retinal blood vessels associated with atrophic macular lesion was studied. A toxoplasma IgG antibody test had been found positive at the age of 4 months. This test and the clinical findings suggested the possibility of optic nerve aplasia with atypical macular coloboma due to congenital toxoplasmosis. The pro's and contra's concerning this hypothesis are discussed by the authors.

Ferning of aqueous humor in the pseudoexfoliation syndrome.

The authors report on the results obtained in the crystallization of the aqueous humor in 6 patients suffering from cataract with pseudoexfoliation syndrome. The principle characteristics of the aqueous in these cases are described and are compared with the features of aqueous humor in 20 cases of uncomplicated cataract. Tetragonal shaped masses of material with a distinct tendency to localization in the intersections of fern patterns were demonstrated in the crystallized aqueous from patients with pseudoexfoliation syndrome. These aggregates most probably correspond to exfoliation material.

Atypical retinitis pigmentosa: a report of three cases.

We report three cases of patients with atypical retinitis pigmentosa (RP): sector bilateral, sector unilateral, and inverse. Clinical and functional features of perimetry, color vision testing, adaptometry, electroretinography, fluorangiography, and audiometry are described. One patient had isolated RP; the others had syndromic RP, combined with defective hearing and celiac disease. Two of these patients were followed for three years and one for 13 years. Their disease courses during the period of observation are discussed.