Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The present study was designed as a cross-sectional survey to assess the association between soft drusen and 'choroidal filling defects'. Sixty-eight eyes presenting hard drusen and 58 eyes with soft drusen of 126 subjects with an age range of 45-83 years were examined in the present study. Choroidal filling defects were present in 13 out of 68 (19.1%) patients with hard drusen and 29 out of 58 (50%) with soft drusen (chi 2 square = 13.4; p < 0.0001 and an odds ratio = 4.2 with 95% CI 1.9-9.3). Age, ocular and systemic hypertension, and diabetes did not influence the results. The association between soft drusen and choroidal filling defects, found in our study, suggests that these abnormalities are possibly due to changes in the staining or permeability properties of Bruch's membrane rather than to a defect in the choroidal blood supply. Soft drusen and choroidal filling defects may both be caused by an accumulation of hydrophobic material within the Bruch's membrane, which is discrete in the case of drusen and diffuse in the case of choroidal filling defects. Choroidal filling defects and soft drusen may represent useful clinical sign of hydrophobicity of Bruch's membrane.
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PMID:Drusen and 'choroidal filling defects': a cross-sectional survey. 148 87

Drusen are subretinal pigment epithelial deposits that are characteristic of but not uniquely associated with age-related macular degeneration (AMD). Age-related macular degeneration is associated with two types of drusen that have different clinical appearances and different prognoses. Hard drusen appear as small, punctate, yellow nodules and can precede the development of atrophic AMD. Areolar atrophy of the retinal pigment epithelium (RPE), choriocapillaris, and outer retina develop as the drusen disappear, but drusen can regress without evidence of atrophy. Soft drusen appear as large (usually larger than 63 microm in diameter), pale yellow or grayish-white, dome-shaped elevations that can resemble localized serous RPE detachments. They tend to precede the development of clinically evident RPE detachments and choroidal neovascularization. Drusen characteristics correlated with progression to exudative maculopathy include drusen number (five or more), drusen size (larger than 63 microm in diameter), and confluence of drusen. Focal hyperpigmentation in the macula and systemic hypertension also are associated with an increased risk of developing choroidal new vessels (CNVs). Large drusen are usually a sign of diffuse thickening of Bruch's membrane with basal linear deposit, a vesicular material that probably arises from the RPE, constitutes a diffusion barrier to water-soluble constituents in the plasma, results in lipidization of Bruch's membrane, and creates a potential cleavage plane between the RPE basement membrane and the inner collagenous layer of Bruch's membrane through which CNVs can grow. Disappearance of drusen spontaneously and in areas adjacent to laser photocoagulation scars was first noted by Gass (Gass JD: Arch Ophthalmol 90:206-217, 1973; Trans Am Acad Ophthalmol Otolaryngol 75:580-608, 1971). Subsequent reports have confirmed these observations. Photocoagulation-induced drusen regression might prevent patients with drusen from developing exudative maculopathy. The mechanism for spontaneous drusen regression probably involves RPE atrophy. The mechanism for photocoagulation-induced drusen regression is unknown. If photocoagulation-induced drusen regression is anatomically similar to atrophy-associated drusen regression, then the former will be associated with dissolution of basal linear deposit and a residuum of basal laminar deposit. Sarks and coworkers (Sarks JP, Sarks SH, Killingsworth MC: Eye 11:515-522, 1997) proposed that this in turn will eliminate the potential cleavage plane between the RPE basement membrane and inner collagenous layer of Bruch's membrane through which CNVs grow, thus retarding the growth of CNVs.
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PMID:Drusen in age-related macular degeneration: pathogenesis, natural course, and laser photocoagulation-induced regression. 1046 85