Subfoveal Choroidal Neovascular Membranes Research Articles

Well-defined Subfoveal Choroidal Neovascular Membranes in Age-related Macular Degeneration

The purpose of this study is to correlate the clinical, angiographic and ultrastructural features of well-defined subfoveal neovascular membranes. Fundus photographs and fluorescein angiograms of five well-defined subfoveal neovascular membranes associated with age-related macular degeneration and exudative retinal detachment were obtained. The subfoveal membranes were surgically excised via the pars plana. The center and peripheral portions of each membrane were evaluated by transmission electron microscopy for cellular and extracellular constituents. Each subretinal neovascular membrane was composed of two distinct regions demonstrated by fluorescein angiography. The first component, the core, contained a brighter central area of hyperfluorescent leakage surrounded by a partial or complete cuff of elevated blocked choroidal fluorescence. Results of ultrastructural examination showed that the core was composed of a fibrovascular membrane characterized by endothelium-lined vascular channels with associated retinal pigment epithelium. The second region of the membrane, the rim, is previously unreported and is described in detail. It appeared as a minimally elevated, smooth, subretinal annular rim of hyperfluorescent staining that surrounded the core and was composed of fibrin, photoreceptor outer segments, and macrophages. Well-defined subfoveal neovascular membranes can be appreciated with fluorescein angiography and are composed of a central core of subfoveal choroidal neovascularization surrounded by a peripheral rim composed of fibrin, photoreceptor outer segments, and macrophages.

Surgical Excision of Subfoveal Neovascular Membranes in Age-related Macular Degeneration

We studied the results of surgical excision of ten consecutive subfoveal choroidal neovascular membranes in ten patients with age-related macular degeneration. The criteria for surgical eligibility included the following: (1) a clearly identifiable subfoveal membrane occupying the entire foveal avascular zone, (2) a visual acuity of 20/200 or worse, (3) minimal subretinal hemorrhage, and (4) an associated exudative macular detachment. Six of the ten patients showed visual improvement at one-month and three-month follow-up visits and seven showed visual improvement by the six-month examination. All ten maculae remained attached without recurrence of subfoveal neovascular membranes throughout the follow-up period. These results suggested that surgical excision is a viable alternative to laser photocoagulation in patients with subfoveal neovascularization in age-related macular degeneration.

Surgical Removal of Submacular Hemorrhage and Subfoveal Choroidal Neovascular Membranes

Surgical Removal of Submacular Hemorrhage and Subfoveal Choroidal Neovascular Membranes

Faecal free fatty acids in tropical sprue and their possible role in the production of diarrhoea by inhibition of ATPases.

Faecal excretion of fatty acids is increased in patients with tropical sprue because of unabsorbed dietary fatty acids. The excretion of fatty acids correlates well with faecal wet weight. In vitro unsaturated fatty acids inhibited Na K-ATPase and Mg-ATPase isolated from basolateral membranes of enterocytes and colonocytes. These findings are a possible explanation for the observed abnormalities in water and electrolyte absorption by the colon in patients with tropical sprue and steatorrhoea.