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Biomedical subjects

J D Gass

Publications and source records attributed to J D Gass.

At least 145 records · Page 8Linked to original sources
PubMed1981

A fluorescein angiographic study of cystoid macular edema.

We performed a prospective fluorescein angiographic study on 66 patients who had undergone extracapsular cataract extractions with implantation of a Shearing posterior chamber intraocular lens. A primary posterior capsulotomy was performed in every case. The eyes were studied 11 to 23 months postoperatively. The incidence of cystoid macular edema (3%) was lower than that found in three series of cataract extractions previously reported. Extracapsular cataract extraction with either (1) a Shearing posterior chamber intraocular lens and a primary posterior capsulotomy or (2) a Binkhorst intraocular lens and an intact posterior capsule produces a lower rate of cystoid macular edema than does intracapsular cataract extraction either with a Binkhorst intraocular lens or without an intraocular lens. There was no significant difference in the incidence of cystoid macular edema in the two extracapsular series, indicating that preservation of an intact posterior capsule was not a significant factor.

Aged↗
PubMed1981

Fluorescein angiography of optociliary shunt vessels.

Progressive loss of vision, optic disc pallor, and optociliary shunt vessels (the Hoyt-Spencer sign) constitute the clinical triad of optic nerve sheath meningiomas. However, optociliary shunt vessels may also follow central vein occlusions, and less commonly occur with a few other conditions. This report presents a comparative study of fluorescein angiograms performed on eight patients with optociliary shunt vessels. Four patients had optic nerve sheath meningiomas, and four patients had central retinal vein occlusions. The following differences in the fluorescein angiograms were noted in the two groups. In the optic nerve sheath meningioma group, the shunt vessels fill earlier (in the arteriovenous phase), the flow drains to central venous tributaries, and the late staining is hyperfluorescent to other veins. However, in the central vein occlusion group, the shunts fill later (in the venous phase), show a flow draining to the outer disc margin, and late staining is eufluorescent with other veins. Although optic nerve sheath meningiomas and old vein occlusions are usually rather easily differentiated by a complete examination, the fluorescein angiographic patterns are not only pertinent with regards to the pathogenesis of optociliary vessels, but in certain cases may be clinically helpful in making an important clinical differentiation.

Adult↗
PubMed1980

Interaction of L- and D-3-amino-1-chloro-2-pentanone with gamma-glutamylcysteine synthetase.

The optical isomers of 3-amino-1-chloro-2-pentanone, which are the alpha-chloroketone analogs of L- and D-alpha-aminobutyrate, were synthesized and found to be highly potent irreversible inactivators of gamma-glutamylcysteine synthetase. These chloroketones are 20 to 30 times more active than L-2-amino-4-oxo-5-chlorpentanoate. L- and D-Glutamate, in the presence of Mg2+ or Mn2+, protect the enzyme against inactivation. The enzyme is almost completely inhibited by cystamine under conditions in which 0.5 mol of this compound is bound/mol of enzyme. Treatment of the enzyme with cystamne, which produces inhibition that is reversible by dithiothreitol, prevents the interaction of the new chloroketones, L-2-amino-4-oxo-5-chloropentanoate and methionine sulfoximine with the enzyme. The findings suggest that a sulfhydryl group at the active site interacts with the chloroketones and with cystamine and that the chloroketone inhibitors and cystamine bind to the enzyme as glutamine analogs. The data also suggest that a gamma-glutamyl-S-enzyme intermediate may be formed in the reaction catalyzed by this enzyme.

Animals↗
PubMed1980

Sessile and exophytic capillary angiomas of the juxtapapillary retina and optic nerve head.

This report concerns six patients with sessile and exophytic capillary hemangiomas of the optic nerve head and juxtapapillary retina. These are probably retinal vascular hamartomas, which are frequently misdiagnosed as unilateral papilledema, papillitis, choroiditis, choroidal neovascularization, or choroidal hemangioma. Stereo fluorescein angiography is essential in identifying these tumors that usually cause loss of central vision by intraretinal and subretinal exudation into the macular region. Photocoagulation treatment was successful in two patients.

Adolescent↗
PubMed1980

Observation of suspected choroidal and ciliary body melanomas for evidence of growth prior to enucleation.

One hundred and sixteen patients with suspected malignant melanoma of the choroid and ciliary body were observed for evidence of tumor growth prior to enucleation. All patients were followed for a minimum of five years after tumor detection. The tumor failed to grow in 69 patients, and none developed evidence of metastatic melanoma. The tumor grew in 47 patients, and 35 patients had enucleation. Five patients (4 having enucleation) died of metastatic melanoma. Deaths caused by other primary malignancies (9 patients) and other causes (11 patients) outnumbered those caused by melanomas. The clinical accuracy of predicting growth of small and medium suspected melanomas was approximately 75%. Five patients died because of metastatic melanoma. This study demonstrated no evidence of increased mortality caused by observation of small tumors for evidence of growth prior to enucleation.

Adult↗
PubMed1980

Follow-up study of presumed ocular histoplasmosis syndrome.

One hundred and sixty-two patients with presumed ocular histoplasmosis syndrome were evaluated. New macular scars not present on initial angiogram developed in 9% of eyes. The risk of developing a symptomatic macular lesion in eyes with asymptomatic macular scars was 23%. In eyes with peripapillary scarring, 3.8% developed a peripapillary neovascular membrane. Follow-up was 5.5 years. When the neovascular membrane was touching or outside the foveal avascular zone, the difference between photocoagulated and control eyes was not statistically significant. When only adequately photocoagulated eyes (20) were compared with control eyes (40), the difference was statistically significant (P = 0.04).

Adolescent↗
PubMed1979

New observations concerning choroidal osteomas.

The clinical and laboratory findings in fifteen patients with nineteen eyes containing choroidal osteomas are summarized. The first case of the disease in a male patient is reported as well as the development of a second tumor in the previously uninvolved eye of an adult patient and the marked enlargement of the tumor in another. The possible etiology of the choroidal osteomas is discussed.

Adolescent↗
PubMed1979

Serous detachments of the retinal pigment epithelium in patients with senile macular disease.

Thirty-one patients had senile macular disease with serous detachments of the retinal pigment epithelium without evidence of choroidal neovascularization. Of these 31 patients the natural history of 24 eyes was compared with 21 eyes treated with photocoagulation. Eight patients with bilateral detachments had treatment applied to one eye. There was no conclusive evidence that photocoagulation alters the natural course of this condition.

Aged↗
PubMed1979

Clinical and follow-up studies of melanocytomas of the optic disc.

Forty patients with melanocytoma of the optic disc were evaluated to determine their clinical variations and behavior. Follow-up examination of 1 to 19 years was obtained in 27 patients. Of the 27 lesions, four (15%) showed a slight increase in size, and one tumor (4%) decreased in size. The remaining 22 tumors (81%) have not yet demonstrated ophthalmoscopic changes. In spite of occasional growth, the melanocytoma is a benign tumor that requires no treatment.

Adolescent↗
PubMed1978

Choroidal Osteoma.

Choroidal osteomas caused visual symptoms in four healthy young women. A positive 32P test led to enucleation and histopathologic confirmation of the diagnosis in one patient. The characteristic ophthalmoscopic findings in these patients included the following: (1) slightly and irregularly elevated, yellow-white, juxtapapillary, choroidal tumor and well-defined geographic borders; (2) diffuse and mottled depigmentation of the overlying pigment epithelium; and (3) multiple small vascular networks on the tumor surface. A diffuse mottled pattern of hyperfluorescence in the area of the tumor occurred during the early and later stages of angiography. The tumors were ultrasonically dense, and the orbital tissue behind them was rendered silent. The tumors were visible on routine orbital x-ray films and computerized tomograms. The latter study demonstrated the tumors as having the consistency of normal bone.

Adult↗
PubMed1978

Diffuse unilateral subacute neuroretinitis.

Thirty-six young healthy patients developed a peculiar clinical syndrome affecting only one eye. The early stage of the disease was characterized by visual loss, vitritis, mild papilledema, and successive crops of multiple, evanescent, gray-white, deep, retinal lesions. Over a period of many months there developed widespread, diffuse and focal depigmentation of the pigment epithelium, retinal arterial narrowing, optic atrophy, severe visual loss, and electroretinographic changes. A motile, subretinal round worm, probably a Toxocara, was observed in two patients.

Adolescent↗
PubMed1976

Lamellar macular hole: a complication of cystoid macular edema after cataract extraction.

A woman developed an inner lamellar macular hole and cellophane maculopathy as a complication of chronic cystoid macular edema following cataract extraction. Fluorescein angiography revealed a cystoid pattern of fluorescence in the paracentral area but no evidence of staining in the region of the hole. Following death, histopathologic examination of both eyes confirmed the clinical observations. Biomicroscopic examination and fluorescein angiography are of value in differentiating an inner lamellar macular hole from a full-thickness macular hole and from a pseudomacular hole caused by spontaneous contraction of an epiretinal membrane.

Cataract Extraction↗