Biomedical subjects

R A Moura

Publications and source records attributed to R A Moura.

14 recordsLinked to original sources

PubMed1989

Combined hamartoma of sensory retina and retinal pigment epithelium.

We report two cases of combined hamartoma of the sensory retina and retinal pigment epithelium (CHR-RPE) in which apparent growth of the lesion was observed. In case 1, the eye was enucleated with a presumed diagnosis of juxtapapillary malignant melanoma. Histopathologically, the enucleated globe showed an elevated peripapillary mass containing disorganized retinal tissue intermixed with vascular and glial elements as well as tubules of proliferating retinal pigment epithelium. We have summarized the clinical features of 53 patients with CHR-RPE reported between 1952 and 1988 excluding the cases compiled by the Macular Society Collaborative Study. While the latter study found an equal sex predilection among their cases, we found a 70% male preponderance among the 53 patients. Of the 54 lesions observed in 53 patients, 76% were juxtapapillary, 17% were macular, and 7% were peripheral. Furthermore, periodic follow-up examination disclosed apparent enlargement of the mass in six patients, five of whom underwent enucleation of the globe for suspected melanoma.

Child↗

PubMed1985

Malignant melanoma of the choroid: treatment with episcleral 198Au plaque and xenon-arc photocoagulation.

A method of treatment for posteriorly located malignant melanomas of the choroid is reviewed. Twenty-six patients have been treated either by radioactive gold (198Au) seed radiation plaque, alone or in combination with postradiation xenon-arc photocoagulation. Success, defined as the preservation of the globe with tumor ablated or regressed, was achieved in 92.3% of the treated eyes. These patients have been followed from 1 to 8.5 years, with an average follow-up of 44.84 months. Fifteen out of 26 patients (57.69%) had a final visual acuity of 20/50 or better. The main complications were radiation retinopathy (19.2%) and cystoid macular edema (19.2%). There were two enucleations, one after 29 months and one after 24 months following treatment.

Adult↗

PubMed1984

Pseudovitreous fluid based on sodium carboxymethylcellulose.

Various materials have been suggested for vitreous replacement following vitreoretinal surgery. We studied the use of a viscous physiologic solution based on sodium carboxymethylcellulose, a synthetic polymer structurally similar to hyaluronic acid. Following vitrectomy this pseudovitreal fluid was injected into the vitreous cavity of rabbits. The material appeared to be well tolerated during a six-month observation period.

Animals↗

PubMed1983

Medulloepithelioma diagnosed by ultrasound and vitreous aspirate. Electron microscopic observations.

Ultrasonography and cytologic examination of the vitreous aspirate established the correct pre-enucleation diagnosis of medulloepithelioma in the case of an 8-year-old boy. The use of a muscle hook allowed the examiner to elevate the eye and bring the ciliary body into adequate ultrasonographic view. Histopathologic examination of the enucleated eye showed a partially pigmented mass composed of elongated neuroepithelial tubules and cords arising from the ciliary body inferiorly. Several tubules displayed a central lumen with rosette-like structures. The tumor was classified as a benign, nonteratoid medulloepithelioma. Electron microscopically the lumens of the rosettes contained myriad, slender microvilli, and were bordered by numerous terminal bar complexes and areas displaying zonula adherens and zonula occludens type junctions. Additionally, invaginating gap junctions, which clearly established that the tumor originated from the ciliary epithelium, were identified.

Biopsy, Needle↗

PubMed1980

Two-step mutation theory for retinoblastoma: ultrastructural support.

This study presents previously unreported ultrastructural support for a model for the incidence of retinoblastoma based upon a two-step mutation theory. Ostensibly uninvolved retina showed rod outer segment atrophy and cone outer segment retention correlating with electroretinography, and obliteration of synaptic development within the outer plexiform layer of the retina. The retinoblastoma obtained at age 9 days demonstrated incipient photoreceptor differentiation within the rosette components and minimal calcification of necrotic regions. A heritable interstitial deletion of the long arm of chromosome 13 is shown to be the basis for this child's congenital retinoblastoma.

Atrophy↗

PubMed1974