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Biomedical subjects

A J Brucker

Publications and source records attributed to A J Brucker.

At least 55 records · Page 3Linked to original sources
PubMed1989

Electroretinogram parameters at presentation as predictors of rubeosis in central retinal vein occlusion patients.

This report evaluates the prognostic value of parametric electroretinography (ERG) techniques in the development of rubeosis in central retinal vein occlusion (CRVO). An ERG protocol was followed on the initial clinic visit for 21 CRVO patients. None of these patients had neovascular complications or any treatment before the ERG examination. The ERG data were used to define an intensity-response (I-R) function, b-wave to a-wave peak ratio (b/a-wave ratio), and 30-Hz b-wave implicit time. A Naka-Rushton function was fitted to the I-R data to obtain values for maximum saturated response (Rmax) and for the log of the half-saturation intensity (log K). The authors' results show that ERG parameters relating both to the effective number of responding retinal elements and to the sensitivity of responding elements have significant prognostic value. Unexpectedly high predictive values were found for the Rmax and b/a ratio, parameters thought to correlate with the effective number of responding elements, compared with log K and 30-Hz implicit time, parameters thought to relate more closely to retinal ischemia. A multiple discriminant analysis, combining information from these ERG parameters, allowed separation of CRVO patients in whom rubeosis would develop from those in whom it would not, with a false-positive rate of only 14%.

Aged↗
PubMed1989

Long-term follow-up of idiopathic central serous chorioretinopathy by fluorescein angiography.

Idiopathic central serous chorioretinopathy (ICSC) is typically described as a self-limited, unilateral disease that affects healthy, young adult males. The authors studied 13 patients (14 eyes) who had documented spontaneous resolution of symptomatic macular detachments. These patients were evaluated in a longitudinal fashion to determine the fate of the retinal pigment epithelium (RPE) as viewed angiographically, both in the initially affected eyes and the fellow eyes. At the time of follow-up examination of the initially affected eyes, nonleaking RPE defects had developed inside the areas of previous serous detachment in all cases. Nonleaking RPE defects had developed outside these areas in six (43%) eyes. Two (14%) eyes had new, asymptomatic macular detachments. Six (42%) fellow eyes had new RPE window defects; two (17%) of them also had active RPE dye leakage resulting in asymptomatic macular detachment at the final examination. Four (29%) originally involved eyes and one (8%) fellow eye lost more than two lines of Snellen visual acuity during the follow-up period. The authors' results suggest that ICSC may be a progressive bilateral disease that develops asymmetrically and causes diffuse RPE changes not localized to the area of serous detachment. Long-term follow-up of these patients may, therefore, be advisable.

Adult↗
PubMed1988

A long Krupin-Denver valve implant attached to a 180 degrees scleral explant for glaucoma surgery.

A long glaucoma valve implant attached to an external scleral explant was used during filtration surgery in 72 eyes: 39 eyes with neovascular glaucoma and 33 eyes with other types of secondary glaucomas or with primary glaucoma in which prior filtration surgery had failed. The implant consisted of an open Silastic tube (outside diameter, 0.64 mm), which was placed into the anterior chamber. The external end of the tube contained a pressure-sensitive (opening pressure, 11 mmHg) and unidirectional slit-valve, and was sutured within the groove of a #220 Silastic explant. The 180 degree explant was placed beneath three rectus muscles and then sutured so that the grooved side was against the sclera, with the anterior edge 8 to 12 mm posterior to the limbus. The long glaucoma valve implant resulted in a large, posterior bleb extending over the area of the Silastic explant. The mean preoperative intraocular pressure (IOP) of 43.9 mmHg in the eyes with neovascular glaucoma was reduced to 17.4 mmHg after a mean follow-up of 20.2 months. The mean preoperative IOP of 38.1 mmHg in the eyes after failure of previous filtration surgery was reduced to 17.6 mmHg at a mean follow-up of 21.0 months. Postoperative IOP was less than 21 mmHg in 77% of eyes with neovascular glaucoma (47% required additional medication) and in 82% of eyes with previous failure of filtration surgery (56% required additional medication).

Adolescent↗
PubMed1986

Laser Doppler velocimetry study of retinal circulation in diabetes mellitus.

Bidirectional laser Doppler velocimetry and monochromatic fundus photography were used to investigate retinal circulation in 26 normal subjects and in 51 insulin-treated diabetic patients with no retinopathy, background retinopathy (BDR), proliferative retinopathy (PDR), and patients with PDR who had been treated by panretinal photocoagulation (PDR-PRP). Measurements were obtained from main temporal retinal vessels in each eye. Venous diameter at the site of laser Doppler velocimetry measurements was significantly greater than normal in patients with BDR and PDR. The maximum velocity of red blood cells was significantly lower than normal in eyes with diabetic retinopathy. Calculated volumetric blood flow rate, however, was not significantly different from normal in eyes with no retinopathy, BDR, and PDR, and was significantly decreased from normal in patients with PDR who had been treated by panretinal photocoagulation. A comparison between this technique and the fluorescein dye dilution technique is provided.

Adult↗
PubMed1986

Effect of panretinal photocoagulation on retinal blood flow in proliferative diabetic retinopathy.

The effect of panretinal photocoagulation (PRP) on retinal volumetric blood flow rate and its regulatory response to hyperoxia was investigated in a main temporal vein of 15 eyes with proliferative diabetic retinopathy, using bi-directional laser Doppler velocimetry and monochromatic fundus photography. At an average of 4 +/- 2 months after the beginning of PRP, retinal venous diameter decreased from an average of 174 +/- 20 micron to 162 +/- 19 micron (P less than 0.01), red blood cell velocity decreased from 1.3 +/- 0.4 cm/sec to 1.1 +/- 0.4 cm/sec (P less than 0.01), and blood flow decreased from 11.5 +/- 3.8 microliter/min to 8.4 +/- 3.3 microliter/min (P less than 0.001). The regulatory response to hyperoxia, characterized by the percentage decrease in retinal blood flow during 100% oxygen breathing, improved from 20 +/- 15% prior to treatment to 45 +/- 12% following treatment (P less than 0.001). The decrease in retinal blood flow is most likely due to a decrease in viable retinal tissue and an improvement in retinal oxygenation following PRP. The increase in the regulatory response to 100% O2 breathing following PRP may also result from such an improved retinal oxygenation.

Adult↗
PubMed1985

Subretinal choroidal neovascularization in birdshot retinochoroidopathy.

We studied four eyes of two patients with bilateral birdshot retinochoroidopathy which developed subretinal choroidal neovascular membranes involving the macula. The subretinal choroidal neovascular membranes in our patients developed six months to five years after the onset of the disease. Both patients described decreasing visual acuities at the time when the choroidal neovascular membranes were identified. Adjacent to the classic depigmented areas of birdshot retinochoroidopathy were increased pigmentation, hemorrhage, or fluid indicative of subretinal neovascularization. Fluorescein angiography confirmed the presence and demonstrated the location of these membranes.

Choroid↗
PubMed1985

Risk factors of branch retinal vein occlusion.

A case-control study of 225 patients with branch retinal vein occlusion (BRVO) and 100 age-matched controls was conducted to assess potential clinical risk factors for BRVO. Male gender, hypertension, and hyperopia were significantly more prevalent in patients with BRVO. There was no significant association with race, diabetes, or chronic open-angle glaucoma.

Aged↗
PubMed1985

Embolic retinopathy due to Corynebacterium minutissimum endocarditis.

Infective embolic retinopathy as a sequela of bacterial endocarditis is described in a 31-year-old woman with mitral valve prolapse. The infective organism, Corynebacterium minutissimum, has not been previously found to cause ocular or multisystem diseases. It is a common mucocutaneous inhabitant which causes erythrasma. In our case report both ocular involvement and septicaemia were present. The infection was confirmed by positive serial blood cultures. Mitral valve prolapse was confirmed by echocardiography. On clinical examination the retinopathy consisted of white intraretinal lesions which resolved with antibiotic therapy. By fluorescein angiography focal areas of hypofluorescence corresponding to the white fundus lesions were present. Optic disc oedema was also seen.

Adult↗
PubMed1984

Pathology of human cystoid macular edema.

The light and electron microscopic findings are reviewed in two patients who had eyes enucleated for peripheral choroidal malignant melanomas. Preoperatively, cystoid macular edema was documented by fluorescein angiography in the melanoma-containing eye in both patients. Intracytoplasmic swelling (edema) of the Müller (glial) cells is the anatomical basis for the macular edema. Intercellular (extracellular) collections of fluid probably are late, endstage results of the process that result form prolonged, excessive, intracellular edema, cell death and disruption. The process probably rests on an ischemic basis, as evidenced by severe changes in the microvasculature. In the one patient in whom the optic nerve was available for study, marked intracellular swelling (edema) of glial cells in the lamina choroidalis of the optic nerve head was present, associated with compression of the adjacent axons. The nearby temporal, parapapillary retina also showed edema of Müller cells, and compression of the nerve fibers (ganglion cell axons), suggesting a more widespread process than was clinically evident. Again, severe changes were present in the microvasculature, both in the optic nerve and parapapillary retina. The underlying cause of the microvasculature changes that lead to ischemia, perhaps an intrinsic pharmacologic agent, is yet to be found.

Choroid Neoplasms↗
PubMed1984

Lasers in ophthalmology.

Many sources of laser light are used in ophthalmology, most commonly the argon, krypton, and Nd:YAG laser. Each is described and evaluated regarding its qualities and advantages. Laser beam therapy can be used for a variety of ophthalmologic surgical procedures; it permits noninvasive, outpatient treatment that until recently has required invasive surgery. As laser knowledge advances, ophthalmic surgeons will be able to choose the wavelength appropriate to treat a variety of diseases.

Argon↗
PubMed1984

Combined hamartomas of the retina and retinal pigment epithelium.

Combined hamartomas of the retina and retinal pigment epithelium are rare fundus lesions. By combining cases seen by members of The Macula Society, clinical data was collected on 60 patients with combined hamartomas. We reviewed the clinical presentations, ophthalmoscopic, and fluorescein angiographic features and differential diagnosis of this tumor. Of 41 patients with adequate follow-up information, 10 (24%) lost at least two lines of visual acuity, usually due to tractional distortion of the fovea, and four (10%) had improved visual acuity following either amblyopia therapy or vitreous surgery for macular traction.

Adolescent↗
PubMed1984

Altered retinal vascular response to 100% oxygen breathing in diabetes mellitus.

The effect of 100% oxygen breathing on retinal blood flow was investigated using laser Doppler velocimetry in 19 normal eyes, and in 41 eyes of insulin treated diabetic patients. Of the diabetic eyes studied, nine had no retinopathy, 18 had background diabetic retinopathy, seven had proliferative diabetic retinopathy, and seven had proliferative diabetic retinopathy that had been previously treated by argon panretinal photocoagulation. Five minutes of 100% oxygen breathing produced an average decrease in blood flow of 61% (SD = 8) in normal eyes, 53% (SD = 10) in NR eyes, 38% (SD = 13) in background diabetic retinopathy eyes, 24% (SD = 18) in proliferative diabetic retinopathy eyes and 54% (SD = 8) in panretinal photocoagulation eyes. In six eyes with proliferative retinopathy measured before and after panretinal photocoagulation, a significant increase in vascular response to O2 was observed following photocoagulation (Wilcoxon signed rank test, P less than 0.05).

Adult↗
PubMed1984

Effect of pure O2-breathing on retinal blood flow in normals and in patients with background diabetic retinopathy.

The noninvasive Laser Doppler velocimetry technique was applied in normal volunteers and in patients with background diabetic retinopathy to determine retinal blood flow during pure oxygen breathing at atmospheric pressure. In normal subjects, five minutes of oxygen breathing produced a 63 +/- 6% decrease in retinal blood flow. In the diabetic patients blood flow decreased by only 36 +/- 15%. A significant correlation between the decrease in blood flow and that of the diameter of the veins was found in the diabetic patients. This was not the case for the normal subjects.

Adult↗
PubMed1983

New instrumentation for fluid-air exchange.

To facilitate fluid-air exchange, we have recently adapted and modified an instrument that has been designed to maintain the anterior chamber of an eye with pressurized air at levels which are pre-set by the surgeon. We have now altered this instrument to provide us with a means of performing a fluid air exchange that obviates the need for changing or refilling the air syringe. The intraocular pressure can be maintained at a predetermined level throughout the procedure, with unlimited filtered air controlled by the surgeon via an uncomplicated automated foot pedal control system.

Air↗
PubMed1983

Choroidal melanoma with retinal perforation and vitreous hemorrhage: a scanning electron microscopic study.

Extensive retinal perforation and subsequent growth within the vitreous cavity permitted the scanning electron microscopic examination of a primary, mixed cell type malignant melanoma of the choroid. The surface of the tumor was covered by fusiform cells oriented in a longitudinal, parallel fashion. Plumper globoid, presumed epitheloid forms were interspersed among the spindle cells. In some areas, the spindle cells had long tapering processes. At the margin of the tumor, slender fascicles of parallelly oriented, proliferating spindle cells were identified. This fascicular growth pattern has been observed in previous tissue culture and scanning electron microscopic studies. Vitreous hemorrhage which occurred in our case may herald a malignant melanoma that has perforated the retina. Additionally, retinal perforation may signify an aggressively growing tumor which should be treated.

Aged↗
PubMed1983

Progressive chloroquine retinopathy.

Chloroquine retinopathy is a well-documented toxic manifestation of a commonly used systemic medication. The major retinal findings are those of macular retinal pigment epithelial changes, narrowed retinal vessels, and scotomatous visual field defects. The fluorescein angiographic findings are those of a retinal pigment epithelial transmission defect that takes on a bull's-eye configuration. We present a patient who had taken chloroquine for two years while in the military service. Two years after discharge, he was examined and reported to have a mild granular appearance to the macula. Over a period of nine years, progressive decreased central acuity prompted repeated fluorescein angiograms, which revealed a progressive bull's-eye maculopathy compatible with chloroquine retinopathy. Evaluation of offspring failed to reveal any evidence of a hereditary macular dystrophy. To our knowledge, this is the first reported case of delayed onset and progression of chloroquine maculopathy documented by fluorescein angiography.

Chloroquine↗
PubMed1981

Macular edema and cystoid macular edema.

We examined the foveomacular regions from three eyes in which fluorescein angiography had demonstrated the characteristic appearance of cystoid macular edema by light and electron microscopy. Cystoid macular edema was present in two eyes (one of which was from a 63-year-old diabetic man) that contained peripheral choroidal melanomas, and in a third eye from a patient with diabetes only. By light microscopy, cystoid macular degeneration was obvious only in the third eye. The electron microscopic findings common to all three eyes were widespread swelling and necrosis of Müller cell cytoplasm. There was no enlargement of intercellular spaces. There was secondary neuronal degeneration. Retinal vascular changes, consisting mainly of endothelial cell abnormalities, were found in all cases but were far more common in the two eyes from diabetic patients. The retinal vascular changes were probably the cause of the cystoid macular edema.

Aged↗