1/7. adult vitelliform macular degeneration: a clinicopathological study.AIMS/BACKGROUND: The yellow lesions of adult vitelliform macular degeneration (AVMD) slowly fade, progressing to hyperpigmentation or atrophy. This study aims to provide further observations on the location and nature of the vitelliform material. methods: This report describes the clinicopathological correlation of four eyes with AVMD. A retrospective histopathological study of a further 526 aged eyes previously graded for the stage of age-related macular degeneration (AMD) found another 10 eyes with similar pathology. RESULTS: The predominant finding was a collection of extracellular material beneath the sensory retina at the fovea. This material was derived internally from photoreceptor outer segments and externally from the retinal pigment epithelium (RPE), the latter first undergoing hypertrophy and then disruption and attenuation. Fallout of foveal cones occurred over these lesions and the inner retina was thinned, which may explain macular hole formation in this condition. All affected eyes showed histopathological evidence of AMD. CONCLUSIONS: This study confirms that the vitelliform lesions of AVMD lie beneath the sensory retina. In contrast to previous reports, however, it is proposed that the lesions comprise mainly extracellular material consisting of photoreceptor debris, possibly the result of faulty phagocytosis by the RPE, mixed with pigment liberated as the RPE undergoes disruption. The vitelliform lesions therefore are a marker for the area of maximal RPE disturbance.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
2/7. Ultrastructural immunocytochemistry of subretinal neovascular membranes in age-related macular degeneration.BACKGROUND: The authors studied various cellular and extracellular matrix components of subretinal neovascular membranes (SRNVM) from patients with age-related macular degeneration (ARMD). methods: Electron microscopic immunocytochemistry was used on the subfoveal neovascular membranes surgically removed from three patients with disciform lesions due to ARMD. FINDINGS: The SRNVMs always contained large "feeder" vessels along with many new capillaries in different stages of maturation. capillaries were sparse and embedded in an abundant stroma. The majority of the nonvascular cells were either retinal pigment epithelial (RPE) cells or fibroblast-like cells. The RPE cells formed single or multiple layers on one side of the membranes. The stroma was composed mainly of collagen types I and IV and fibronectin, with small amounts of collagen types III, V, and VI. The absence of Bruch's membrane suggests that a splitting may occur between the RPE cells and Bruch's membrane with the new vessels growing into this cleft. A thickened layer of collagen type iv was often present under the RPE cells. The basement membranes of the newly formed capillaries were morphologically ill-defined, and contained substantial amounts of collagen type iv and fibronectin, but, unlike the basement membranes of normal capillaries, they lacked laminin or heparan sulfate proteoglycan. CONCLUSION: These results on the ultrastructural components of the SRNVMs may be useful in clarifying the nature of the disciform process in ARMD.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
3/7. Diffuse drusen and associated complications.An eye of a patient with an unusual form of diffuse drusen was studied by light and electron microscopy. Examination disclosed marked diffuse and nodular thickening of the inner portion of Bruch's membrane by vesicular and curvilinear membranous profiles and basement membrane-like material that was apparently derived from the retinal pigment epithelium. Deposition of this abnormal material suggests a diffuse abnormality of the retinal pigment epithelium and predisposes to serous detachment of the retinal pigment epithelium, choroidal neovascularization, hemorrhagic detachment of the retinal pigment epithelium, and disciform scarring. The features of this case are similar to previously reported cases of diffuse drusen, but differ in the early age of onset, intensity of changes, and, in part, by the nature of the abnormal material observed.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
4/7. Best's vitelliform macular dystrophy.We examined and evaluated the ophthalmological findings of 47 patients with Best's vitelliform macular dystrophy (BVMD) and 5 cases suffering from related conditions to this macular disorder. Our sample re-confirm that BVMD is a progressive disease which may have several appearances in the course of its evolution. The heredity of this disorder is autosomal dominant with reduced penetrance and variable expressivity. Some contradictions exist regarding the nature of the primary defect in this entity. Electrooculographic and angiographic investigations lend support to the belief that the basic pathological changes are located in the retinal pigment epithelium. However, recent histopathological findings and flicker electroretinographic results indicate the possibility that the photoreceptor cells are equally involved, even before the pigment epithelium. In view of the existing disagreements about the pathogenesis of this disorder, certain considerations were advanced which suggest that the basic pathologic process in this entity produces a disorganisation in the structural and functional interdependance of both the photoreceptor cells and pigment epithelium.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
5/7. Focal macular choroidopathy.The clinical and angiographic findings in 2 patients with focal macular choroidopathy (FMC) are described. Follow-up fluorescein angiography revealed that the initial lesions consisted of multifocal, whitish spot-like areas of choroidal infiltration with hyperfluorescence in the late phase angiogram. At a later stage of the disease, the developing disciform macular lesion showed subretinal neovascularization. The disease was bilateral with poor visual prognosis. There was no evidence of infection with histoplasma capsulatum. Early oral corticosteroid treatment could not prevent the progressive nature of the disease.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
6/7. Surgical removal of an extrafoveal fibrotic choroidal neovascular membrane with foveal serous detachment in age-related macular degeneration.BACKGROUND: Visual recovery after submacular surgery for age-related macular degeneration (AMD) has been very limited. methods: A patient with an extrafoveal fibrotic choroidal neovascular membrane from AMD had an overlying serous foveal detachment with the fibrotic tissue elevating the foveal retina. Photocoagulation of the neovascular membrane was not recommended because of its nonpigmented, fibrotic nature. The membrane was surgically excised. RESULTS: Preoperative and postoperative visual acuity and central 30 degrees visual fields were followed. visual acuity improved from 20/200 to 20/25, and a preoperative central scotoma resolved completely 18 months after surgical excision of the extrafoveal fibrotic neovascular membrane. There were no intraoperative or postoperative complications. CONCLUSION: This type of patient may represent a distinct subset of patients with AMD amenable to subretinal surgery who could potentially have good recovery of vision.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
7/7. Clinicopathologic correlation of drusen and retinal pigment epithelial abnormalities in age-related macular degeneration.BACKGROUND: Clinicopathologic studies of eyes lead to a better understanding of the nature of the ophthalmoscopic and fluorescein angiographic features of drusen. A study was conducted to provide clinicopathologic correlation of drusen and present a classification of drusen based on clinical and histopathologic features. methods: The macular areas of three eyes from two patients were serially sectioned and studied, and features were depicted in a two-dimensional map and compared with clinical findings. RESULTS: All three tyes had large drusen (> 63 microns) with soft morphologic characteristics (poorly demarcated borders) documented on fundus photographs. In both eyes from one patient, these large drusen corresponded to areas of focal retinal pigment epithelium hypopigmentation overlying Bruch's membrane, which was diffusely thickened throughout the macula. Similar findings were noted in another eye from a second patient, and additionally, where there was relatively marked fluorescein staining of large drusen on the late phase of an angiogram, the pathologic correlation demonstrated detachment of the thickened inner aspect of Bruch's membrane from the remainder of Bruch's membrane. Focal hyperpigmentation corresponded to areas of hypertrophy of the retinal pigment epithelium and to clusters of pigmented cells in the subretinal space and outer nuclear area. CONCLUSION: Diffuse thickening of the inner aspect of Bruch's membrane is associated with retinal pigment epithelial hypopigmentation, focal atrophy, and soft (large) drusen formation.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |