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Biomedical subjects

S Sarks

Publications and source records attributed to S Sarks.

5 recordsLinked to original sources
PubMed2006

Development of atrophy of the retinal pigment epithelium around disciform scars.

BACKGROUND/AIMS: Eyes with burnt out disciform scars secondary to age related macular degeneration (AMD) are regarded as visually stable. The aim of this study is to report the subsequent development of atrophy of the retinal pigment epithelium (RPE) around the scars and discuss the possible basis. METHODS: 20 eyes from 18 patients were observed to develop atrophy around choroidal neovascularisation (CNV). A method of measuring expansion of the atrophy over time is described using the Topcon Imagenet 2000 system. An additional 10 clinicopathological examples were reviewed. RESULTS: Clinically CNV became surrounded initially by a ring of pallor that progressed to an expanding band of atrophy of the RPE. It developed most rapidly in the first 3 years after CNV became quiescent but then continued to expand slowly to more than three times the size of the scar. Histopathological specimens showed large choroidal vessels entering the scars directly and a reduced number of small choroidal vessels beneath and around the scar CONCLUSIONS: Disciform scars may become surrounded by an expanding band of atrophy of the RPE, postulated to result from remodelling of the choroidal circulation. The ongoing enlargement of the resulting scotoma may need to be considered when planning management and assessing treatment outcomes.

Aged↗
PubMed1997

Widespread choroidal insufficiency in primary open-angle glaucoma.

PURPOSE: The purpose of this study was to investigate choroidal perfusion in glaucoma, using histological and angiographic techniques. METHODS: We examined the choroidal vasculature in clinicopathological slides from 25 cases of primary open-angle glaucoma, five cases of optic atrophy, and 18 normal eyes. We measured choroidal thickness at fixed distances from the disk margin with light microscopy. Using a quantitative computer image analysis system, we established the depth of all vessels and the best fitting diameter and width-to-length ratio for each vessel in three pairs of eyes. Separate statistical analyses were done on the parapapillary area and the whole choroid. We compared standard fluorescein angiographic measures to peak choroidal filling time in a further 78 glaucoma and 84 normal eyes. RESULTS: Choroids were significantly (approximately 50 microns) thinner in glaucoma than in normal or optic atrophy irrespective of fundal position. Vessel frequency and mean diameter, relative to normal, showed greatest decrease near the choriocapillaris. Peak choroidal filling was the only fluorescein angiographic measure that was significantly delayed in glaucoma irrespective of age. CONCLUSIONS: Reduced choroidal thickness in primary open-angle glaucoma is primarily due to loss of the innermost choroidal vessels. Overall size decreases without significant flattening. These changes are not seen with optic atrophy alone and may be correlated with the delayed choroidal perfusion seen in fluorescein angiography.

Aged↗
PubMed1985

Retinal changes in myotonic dystrophy: a clinicomorphological study.

This report appears to be the first ultrastructural study of the maculopathy and peripheral pigmentary retinopathy in myotonic dystrophy. Nine eyes from five patients observed during life are described. The findings were similar in all eyes, the retinal pigment epithelium in the macular region containing an accumulation of lipofuscin in large hyperpigmented cells. Pigment-laden profiles found in the subpigment epithelial space or subretinal space were interpreted as an attempt to discharge the pigment. Stress fibres of actin microfilaments were thrown into prominence by the irregularity of the pigment epithelium. In the periphery migration of retinal pigment cells into the retina occasionally resulted in the formation of bone corpuscles around occluded vessels, as occurs in retinitis pigmentosa; but more often the clumps were coarser and surrounded basement membrane material. Central and peripheral epiretinal membranes were also observed.

Cataract↗
PubMed1984

An ultrastructural study of the role of leucocytes and fibroblasts in the breakdown of Bruch's membrane.

Ultrastructural examination was performed on 30 eyes selected on the basis of a light microscopic classification as representing all stages of macular degeneration. The eyes belonged to 29 patients aged 40 to 91 years at death and all patients with the exception of the 40-year-old had been examined during life. The results indicate that monocytes, lymphocytes, fibroblasts and mast cells may play a role in the formation of breaks in Bruch's membrane at early and late stages of macular degeneration. The implications of these observations are discussed in the context of their possible role in choroidal neovascularization.

Adult↗