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Biomedical subjects

B C Daicker

Publications and source records attributed to B C Daicker.

12 recordsLinked to original sources
PubMed1995

Dystrophic calcification of an implanted hydroxyethylmethacrylate intraocular lens.

Hydroxyethylmethacrylate is a biomaterial still under clinical trial for use in foldable intraocular lenses. We observed a patient in whom a geographic opacification developed within an implanted hydroxyethylmethacrylate lens, together with granular deposits on the posterior lens capsule and in the scar of a paracentesis. The intraocular lens and posterior lens capsule were removed because of impaired visual acuity. Light and scanning electron microscopy disclosed nodular calcifications within the intraocular lens and granular, partially crystalline, calcifications on the posterior lens capsule. Energy-dispersive x-ray analysis and x-ray diffraction showed the deposits in the intraocular lens to consist of calcium hydroxyapatite. We presume this mineralization to be dystrophic, with calcium derived from lens remnants and phosphorus possibly derived from a thymoxamine solution used briefly during the cataract operation. Our observation suggests caution in the use of phosphated solutions together with hydroxyethylmethacrylate intraocular lenses and may warrant reconsideration of the suitability of hydroxyethylmethacrylate intraocular lenses, should additional similar cases be reported.

Aged↗
PubMed1989

Congenital hypertrophy of the pigment epithelium: light microscopic and ultrastructural findings in young children.

Two cases of autoptically observed congenital hypertrophy of the retinal pigment epithelium (CHRPE) in a newborn and in an infant, one with electron photomicrographs, are presented. In contrast to the adjacent RPE cells, the apical cellular surface of CHRPE cells shows only rare small microvilli, mostly at the cell border. The prominent findings are large pigment granules from 3.5 to 8 microns protruding towards the apical cellular surface. These macromelanosomes do not exhibit coalescence as noted by others, but show a concentric lamellar structure that may be the result of a disturbed development sequence in melanin granule formation. The authors' observation of CHRPE in a newborn and in an infant suggests that the term congenital HRPE is appropriate. The presence of these changes at this early age is consistent with the condition being a primary failure of differentiation. Finally, the authors present evidence of a disturbed melanogenesis in CHRPE cells resulting in macromelanosomes formation.

Child↗
PubMed1981

[Acquired black disc and melanotic retina after resection of an orbital meningioma (author's transl)].

Resection of an orbital meningioma in a 53-year-old patient caused an occlusion of the central retinal artery and total ophthalmoplegia. Eight weeks postoperatively rapid development of a black disc was observed with migration of pigment into the juxtapapillary retina. One year later the eye was removed during a radical reoperation. Histological and ultrastructural examination showed that the melanosis of the disc and the retina was apparently due to reactive proliferation of the juxtapapillary pigment epithelium which had migrated into the atrophic tissues of the retina and the disc. The histological differentiation from hamartomatous proliferations of the juxtapapillary pigment epithelium is discussed. The proliferated pigment epithelium cells in this patient resemble those described in epiretinal membranes apart from abundant RER and actin filaments. In the absence of mechanical or inflammatory factors it must be assumed that hypoxia was the stimulus responsible for the proliferation. The presence of fenestrated retinal capillaries in the proliferation zone is described and the significance of this finding is discussed.

Arterial Occlusive Diseases↗
PubMed1980

[Focal epiretinal fibroplasias overlying photocoagulations in diabetic retinopathy (author's transl)].

This clinico-pathological study compares photocoagulated diabetic retinae with cases of spontaneous epiretinal fibroplasia. Focal epiretinal fibroplasias were found overlying 5-10% of the Xenon-arc photocoagulations but not over Ruby-laser coagulations. These foci are contiguous-forming membranes but they do not cause surface wrinkling. The topography and appearance of the fibrous components of these membranes in trypsin-digest specimens are described and compared with foci of spontaneous epiretinal surface wrinkling. Destruction of the inner retinal surface by heavy coagulation is believed to be the principal cause of focal post-photocoagulation fibroplasia. Other possible pathogenetic factors are discussed.

Adult↗
PubMed1979

[Mulitiple myxoma of the eyelid].

Case report of a man aged 41 with several myxomas of the lids. At the age of 10 years a myxoma of the nose, primarily interpreted as myxosarcoma, was removed surgically and irradiated. 7 years later a myxoma developed on his right lower lid and 31 years later 3 more myxomas appeared on his left upper lid. The histology of this rare kind of lid tumour is described and the unusual course discussed.

Adolescent↗
PubMed1979

[Retinal surface wrinkling and epiretinal membranes in hemorrhagic secondary glaucoma (author's transl)].

Wrinkling of the retinal surface was found histologically in 54,5% of 88 globes enucleated because of hemorrhagic secondary glaucoma. In 92% of these cases the wrinkles were associated with epiretinal membranes. These were divided into: cellular, fibrous and mixed fibrocellular membranes. The combination of surface wrinkling and pure cellular membranes, interpreted as glial in nature, was found in only 6% of cases while fibrous and mixed membranes occurred in 85% of cases. The fibrous component seems therefore to be an important factor in surface wrinkling retinopathy. Age, sex, intraocular pressure and previous surgery did not influence the frequency or type of these spontaneous epiretinal fibroplasias of vascular etiology.

Adult↗
PubMed1978

[Wound healing in the feline retina following mechanical trauma (author's transl)].

The healing of superficial retinal scratches inflicted with a Sato knife was followed from days 1 to 135 in 20 domestic cats. Breakdown of retinal tissue continued for 18 weeks. Glial proliferation was extremely sparse and never observed before day 6. Microvilli and cell processes, derived mainly from Müller cells, were also seen in the wound. Regeneration of the internal limiting membrane was never observed. The choroid, pigment epithelium, retinal blood vessels, and vitreous played no part in the healing process.

Animals↗
PubMed1978

[Orbital chordoma].

The clinical course, autopsy findings and histological appearance are described in a case of malignant chordoma of the skull base involving the orbits, paranasal sinuses, nasal cavity, and the middle and posterior cranial fossa. Exophthalmos developed early as an unusual symptom in association with ocular pareses, visual detoriation and visual field loss. The clinical and histological characteristics of this rare tumour are briefly reviewed and compared with the findings in the present case.

Aged↗
PubMedDate not supplied

Ocular pathology in light chain deposition disease.

Light-chain deposition disease (LCDD), a rare form of monoclonal gammopathy, is characterized by deposits of amorphous light-chain material, mainly in the kidneys but also in various other organs. Here we present the first report of a light-, electron microscopic and immunohistochemical study of the globes of a patient suffering from LCDD secondary to multiple myeloma. Massive deposits of kappa light chains similar to those typically present in the kidneys were found beneath the basement membrane of the ciliary pigment epithelium, on vessels of the ciliary body, within the collagenous zones of Bruch's membrane, and in the innermost part of the choroid. The choriocapillaris in the macular area was partly obstructed by these deposits, and an exudative retinal detachment was present. Whether this detachment was the consequence of disturbed circulation of the choriocapillaris remains speculative.

Adult↗