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Biomedical subjects

J R Gonder

Publications and source records attributed to J R Gonder.

At least 19 recordsLinked to original sources
PubMed1992

Trans-scleral neodymium: YAG retinal photocoagulation in rabbit eyes.

To assess the ability of trans-scleral application of the continuous-wave neodymium: YAG laser to produce retinal ablation with reproducible chorioretinal scars, retinal photocoagulation with the YAG laser was done in four Dutch-belted rabbits (eight eyes). Sharply defined, reproducible lesions were produced that were identical to those found following conventional treatment with the argon laser. At 0.2 J there was destruction of the outer retinal layers with sparing of the inner retinal layers. At 3.0 J full-thickness retinal reorganization was noted; however, even at this energy setting there was minimal histologic evidence of scleral damage. Focused laser energy produced distinctly more retinal destruction and obliteration of the retinal pigment epithelium than unfocused energy. The results suggest that trans-scleral photocoagulation with the YAG laser may be possible and would be particularly applicable in situations in which media opacities preclude visualization of the retina.

Animals↗
PubMed1992

Ocular sarcoidosis presenting as a solitary choroidal mass.

Ocular sarcoidosis presenting as a solitary choroidal mass without other signs of intraocular inflammation is a rare manifestation of systemic sarcoidosis. The authors describe a 26-year-old man who presented with a solitary choroidal tumour. Ocular and general physical examination as well as serum chemistry studies and pathological examination of a lymph node biopsy specimen confirmed sarcoidosis as the cause of the mass. Treatment with systemic steroids resulted in improvement in the appearance of the lesion; however, the visual acuity remained impaired. Other such cases reported in the literature are reviewed.

Adult↗
PubMed1992

Low-dose tamoxifen retinopathy.

A 68-year-old woman with metastatic breast carcinoma manifested bilateral tamoxifen-induced retinopathy after 9 years of low-dose therapy. Treatment with the drug was stopped, with partial resolution of the retinopathy and improvement in visual acuity over 2 1/2 years of follow-up.

Aged↗
PubMed1992

Effect of vitrectomy and cytopreparatory techniques on cell survival and preservation.

Obtaining vitreous fluid by means of vitrectomy frequently results in a specimen that is difficult to assess cytologically. We devised an experimental model to examine the effect of the vitrector on human leukemic cancer (HL60) cells in suspension and to evaluate the cytopreparatory techniques of membrane filtration and cytocentrifugation. Eighteen 3-mL specimens of cells at concentrations ranging from 1 to 9 x 10(5)/mL were vitrectomized, and eighteen 3-mL control samples matched for cell concentration were obtained atraumatically. No significant difference in cell loss, as determined by means of staining with nigrosin vital dye, was found at any cell concentration between the vitrectomized and control specimens. The specimens were then processed cytologically. On cytologic assessment it was not possible to distinguish the vitrectomized and control specimens. A higher degree of cell preservation was noted at higher cell concentrations regardless of the cytopreparatory technique, but at lower concentrations membrane filtration resulted in a higher proportion of cytologically assessable specimens than did cytocentrifugation (42% vs. 22%). The results suggest that the vitrector causes minimal cellular damage and that to obtain optimal results both cytopreparatory techniques should be used with all vitrectomy specimens.

Cell Count↗
PubMed1990

Choroideremia associated with an X-autosomal translocation.

A patient with mild choroideremia has been shown to carry a balanced translocation between chromosome X and 13-46,X,t(X;13)(q21.2;p12). Loci (DXY21, DX232, DX233) shown to map to this region on the X chromosome and in some cases to be deleted in other patients with choroideremia are intact in the DNA from this patient. To our knowledge this is the first report of a translocation associated with choroideremia. One of the translocation chromosomes, derivative 13, free of the derivative X and normal X, has been isolated in a somatic cell hybrid. Because of the clinical association of the eye findings with chromosome interchange, we suggest that the breakpoint on the X is at or near the choroideremia locus. Further analysis of this translocation may be useful in cloning the choroideremia gene.

Adult↗
PubMed1990

Oxygen-induced proliferative retinopathy in the newborn rat.

The neonatal rat, which has an immature retinal vasculature at the time of birth, is a potential animal model for retinopathy of prematurity since it has an established spindle cell retinal vasoformation pattern similar to that seen in the human. To determine if proliferative oxygen-induced retinopathy can be produced in the rat, 40 newborn rat pups were exposed from birth either to air for 25 days or to an 80% oxygen environment for 10 days, followed by 15 days in air. Extraretinal neovascularization was observed in 80% (16/20) of the rat pups exposed to hyperoxia (p less than 0.001) with a bilaterality of 87.5% (14/16). Mild to moderate vitreous hemorrhage was seen in only three eyes. Mesenchymal shunt or ridge formation was not demonstrated, nor was retinal detachment.

Animals↗
PubMed1989

Leiomyoma of the iris.

A 77-year-old white woman presented with a lightly pigmented iris lesion assumed clinically to be an iris melanoma. Light microscopy of the excised tumour showed it to be a spindle-cell tumour. Electron microscopy confirmed the diagnosis of leiomyoma of the iris.

Aged↗
PubMed1988

Successful treatment of the ocular ischemic syndrome with panretinal photocoagulation and cerebrovascular surgery.

The ocular ischemic syndrome is a manifestation of chronic vascular insufficiency. The natural history is for progressive visual loss. The authors describe 12 patients (13 eyes) who presented with at least one asymmetric ocular finding, including midperipheral dot and blot hemorrhages (hypoperfusion retinopathy) (in 8), iris neovascularization (in 7), neovascular glaucoma (in 3) and vitreous hemorrhage (in 1). Cerebral angiography revealed stenosis or occlusion of the ipsilateral carotid artery in all cases. The treatment was panretinal photocoagulation (in four cases), cerebrovascular surgery (in three) or both (in six). All but one patient showed stabilization of visual acuity (20/60 or better in nine cases) and regression of proliferative retinopathy and of iris neovascularization. The results underline the importance of early recognition and treatment of the ocular ischemic syndrome.

Cerebral Angiography↗
PubMed1987

Endophthalmitis due to Oerskovia xanthineolytica.

Unilateral endophthalmitis developed in a 47-year-old man following an intraocular eye injury with a metallic foreign body. Eventually, Oerskovia xanthineolytica was isolated from the vitreous humour. To our knowledge this is the first documented case of endophthalmitis caused by this organism in humans. The clinical course and management of this opportunistic infection are discussed.

Bacterial Infections↗
PubMed1985

Branch retinal artery occlusion after excessive use of nasal spray.

A young, otherwise healthy man presented with an acute retinal artery obstruction following excessive use of oxymethazolone hydrochloride 0.5% (Afrin) nasal spray. Platelet coagulation studies indicated a platelet aggregation hypersensitivity to adenosine diphosphate and epinephrine. A predisposition for sympathomimetic drug-induced platelet fibrin embolus formation appears to be the cause of the retinal artery obstruction in this case.

Adult↗
PubMed1985

Giant retinal tears, retinal detachment and retinitis pigmentosa.

A patient with retinitis pigmentosa and sensorineural deafness presented with bilateral giant retinal tears and a unilateral retinal detachment. The peripheral visual field loss could have been erroneously ascribed to the primary retinal dystrophy. A retinal detachment must be considered in patients with a sudden loss of visual acuity or field even if they have a primary retinal dystrophy.

Adolescent↗
PubMed1985

Ocular and oculodermal melanocytosis.

Thirty-three cases of ocular (27) or oculodermal (6) melanocytosis were reviewed to determine the ocular structures involved by the melanocytic hyperpigmentation. The hyperpigmentation was clinically documented to involve all quadrants of the eye in the majority of the subjects; however, nine persons had sectorial involvement. The choroid and episclera were involved diffusely or sectorially in all the subjects, and the anterior chamber angle and iris were involved in most cases. The conjunctiva, lens and optic disc were less frequently involved. Ten persons had a uveal malignant melanoma in the hyperpigmented eye, and in three of the cases the melanoma had arisen in the hyperpigmented sector. Melanocytic involvement of the trabecular meshwork was not clinically correlated with elevated intraocular pressure.

Eye↗
PubMed1984

Growth rates and doubling times of posterior uveal melanomas.

Seventeen patients having a posterior uveal melanoma underwent enucleation following documentation of tumor growth. Duration of follow-up from diagnosis to enucleation ranged from 3 weeks to 30 months. The mean rate of enlargement in cubic tumor volume was 56.3 mm3/mo for eight spindle cell melanomas and 270.3 mm3/mo for nine mixed cell melanomas. The mean tumor doubling time calculated according to the exponential growth equation was 291.6 days for the eight spindle cell melanomas and 128.2 days for the nine mixed cell melanomas. The mean mitotic activity was 3.5 mf/40 hpf for the eight spindle cell melanomas and 5.4 mf/40 hpf for the nine mixed cell melanomas. These results suggest that mixed cell posterior uveal melanomas generally grow faster and have shorter doubling times than do spindle cell melanomas.

Adult↗
PubMed1984

Ocular involvement in thrombotic thrombocytopenic purpura: the angiographic and histopathological features.

We report two cases of thrombotic thrombocytopenic purpura (TTP). The first case illustrates the clinical findings and fluorescein angiographic features of this disease, notably the serous macular detachments and focal areas of choriocapillaris occlusion. The second case demonstrates a more severe case of TTP, with neurologic complications that led to death; histopathological examination of the eyes showed serous retinal detachments and choriocapillaris occlusion, with electron microscopic evidence of intravascular fibrin-platelet thrombi.

Adult↗
PubMed1984

Evulsion of the optic nerve: a clinicopathological study.

Four patients with evulsion of the optic nerve caused by blunt trauma were clinically evaluated. The evulsion was complete in two of the patients and incomplete in the other two. The patients' visual acuity ranged from counting fingers to no light perception. In addition, two eyes were histopathologically studied. Several explanations of the exact cause and the extent of the evulsion are advanced within this report.

Adolescent↗
PubMed1983

Recurrent microhyphema in the pseudophakic eye.

Although painless transient obscurations of vision are usually attributed to conditions affecting the posterior segment, careful slit-lamp, gonioscopic, and angiographic evaluations may establish an anterior segment origin for these symptoms. Recurrent hyphema, an uncommon late complication following routine cataract extraction, can be caused by spontaneous rupture of incisional vessels. In pseudophakic eyes, the uveitis-glaucoma-hyphema (UGH) syndrome and intermittent visual "white out" are late complications that may necessitate removal of the implant. The authors report five patients with uncomplicated extracapsular cataract extraction and implantation of a Binkhorst biplane, two-loop, capsule-fixated lens who presented with episodes of visual white out on the basis of iris bleeding. Argon laser photocoagulation to sites of iris leakage, at points of lens iris contact, resulted in prompt cessation of bleeding. Laser treatment appears to be a safe and effective alternative to removal of an otherwise satisfactory intraocular lens.

Aged↗