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Biomedical subjects

S J Bass

Publications and source records attributed to S J Bass.

At least 19 recordsLinked to original sources
PubMed2000

Visual-field defects in well-defined retinal lesions using Humphrey and Dicon perimeters.

BACKGROUND: This study was undertaken to correlate field defects in patients having well-defined retinal lesions within the central 30 degrees using Humphrey and Dicon perimetry standard threshold programs and to compare these results against the standard of fundus photography. METHODS: Eleven eyes of 11 patients had various well-defined retinal lesions. Ten of those subjects had best-corrected visual acuity of 20/25 or better. Subjects had either one previous field or no previous experience with any automated perimeter and were tested using either the 30-2 Full Threshold or SITA Standard program of the Humphrey Field Analyzer (HFA) Model 750 and the Central Grid Threshold program (#9) (a full-threshold program) of the Dicon LD-400 perimeter. Defects were scored and compared with fundus photographs scored by an independent observer. RESULTS: Significant high positive correlation coefficients were found between Humphrey, Dicon, and fundus photography, for mean number of significant field defects and for mean deviations. There were no significant differences between the mean scores, mean deviations, or fixation loss percentages. The time the patient occupied a perimeter was 56% less with the Dicon perimeter than with the Humphrey perimeter when the Full Threshold test was used and 8% less when the SITA Standard was used. CONCLUSION: In this study of patients with well-defined retinal lesions, both Humphrey and Dicon Central Threshold field programs exhibited an equally high positive correlation in mapping scotomas of expected size and depth when compared with fundus photography, with no significant difference in fixation loss frequency. However, the total testing time was less with Dicon perimetry than with Humphrey perimetry.

Adolescent↗
PubMed1996

Laser treatment of macular disease.

The introduction of laser photocoagulation for the treatment of macular disease has enabled many patients to retain visual acuity and retard additional deterioration of vision. Treatable maculopathy can occur as the result of choroidal neovascular development, idiopathic central serous choroidopathy, and retinal vascular disease. Variations in the treatment of these maculopathies include type of laser used, spot size, duration of treatment, burn pattern, and intensity of the burn. The cause of the maculopathy determines the type of laser photocoagulation that is most appropriate. While some forms of treatment leave characteristic scars, others leave hardly a trace. Use of fluorescein angiography, and in some cases indocyanine green angiography, is essential in the determination of the appropriate laser treatment modality.

Choroid↗
PubMed1995

Flash visual evoked potential (VEP) in amblyopia and optic nerve disease.

Amblyopia and optic atrophy are two very different causes of unilateral long-standing visual impairment. Yet, in some patients the differential diagnosis is not always manifest and standard clinical tests may fail to provide accurate information. We tested the efficacy of a nonstandard clinical test [flash visual evoked potentials (VEP's)] and quantitative multivariate statistical techniques as aids in the assessment of this differential. Thirty-three patients were separated into four groups (normal, anisometropic amblyopia, strabismic amblyopia, and unilateral optic atrophy). Non-patterned flash VEP's were obtained using several different temporal frequency rates. Patients with optic atrophy had significantly reduced VEP's in the affected eye at all temporal frequencies. Strabismic amblyopes, but not anisometropic amblyopes, often showed supranormal responses in the affected eye at the higher temporal frequencies. Finally, by using discriminant analysis (DA) we were able to classify correctly almost 70% of the patients, well above chance level of 25%. This DA provided very good sensitivity and specificity. We have shown that the use of flash VEP's and of multivariate statistical techniques may provide an effective way to diagnose amblyopia differentially from optic atrophy.

Amblyopia↗
PubMed1995

Atypical herpetic endotheliitis.

BACKGROUND: Three patients ranging in age from 26 to 40 years presented with unilateral posterior stromal lesions with diffuse stromal edema. There was no history of prior surgery, trauma, infectious disease, dystrophy or exposure to noxious agents. Only one patient had signs of anterior chamber reaction and none of the patients showed any sign of epithelial involvement or of associated blood vessels or scarring. All three patients presented with features atypical of herpetic disease, such as lack of epithelial involvement and posterior stromal opacification. They also demonstrated many of the typical characteristics of herpetic disease, however, and thus were diagnosed as having herpetic endotheliitis. RESULTS: All three patients were treated with a regimen of antiviral agents and corticosteroids. Two patients improved, although the time frame differed in each. One patient subjectively improved, then worsened 1 month later after discontinuing treatment on her own. She was lost to subsequent follow-up. CONCLUSIONS: Young patients presenting with unilateral posterior stromal opacification and stromal edema in the absence of epithelial involvement are likely to have endotheliitis of herpetic origin.

Adult↗
PubMed1992

Evaluation of acute urinary tract infection in children by dimercaptosuccinic acid scintigraphy: a prospective study.

A prospective study examining the incidence of dimercaptosuccinic acid (DMSA) abnormalities in children at the time of acute urinary tract infection, the progression of these abnormalities following treatment and their correlation with the presence of vesicoureteral reflux is reported. DMSA scans performed within 72 hours of presentation in 65 previously healthy children with acute urinary tract infection were abnormal in 34 (52%). The scan appearances of 30 of 36 (83%) initially abnormal kidneys improved or became normal on the repeat DMSA study performed at 3 to 6 months after the acute urinary tract infection. A cystogram demonstrated significant vesicoureteral reflux in 11 of 45 cases (24%). Of these 11 cases 10 had abnormal DMSA studies and 1 had dilated upper tracts on ultrasound. Several conclusions may be drawn from our study. The incidence of DMSA abnormalities at the time of acute urinary tract infection is high but these abnormalities tend to resolve with time. An abnormal DMSA study at the time of urinary tract infection identifies most children with significant vesicoureteral reflux, and in our series a combination of ultrasound and DMSA identified all cases. This study may have major implications for the clinical investigation of children with urinary tract infection.

Acute Disease↗
PubMed1991

The detection of reflux nephropathy in infants by 99mtechnetium dimercaptosuccinic acid studies.

Dimercaptosuccinic acid (DMSA) studies were performed in 113 infants less than 1 year old at risk of renal scarring. Of these patients 86 presented with urinary tract infection and 27 were asymptomatic. A voiding cystourethrogram was performed in all cases and excretory urography (IVP) was done in 99. More abnormalities were detected by DMSA study when compared to scars on IVP. When both studies were abnormal there was an excellent correlation on a site by site basis. Fever or systemic disorder was not a reliable sign to determine whether there was upper tract involvement with infection. The incidence of DMSA abnormalities in infants increased with high grade vesicoureteral reflux and decreased with low grade reflux. There was no significant difference in the incidence of abnormal kidneys between the infected and noninfected groups, suggesting that renal scarring may occur with sterile reflux.

Female↗
PubMed1991

Corneal dystrophies.

Corneal dystrophies are inherited (usually autosomal dominant) disorders involving virtually every layer of the cornea. They result in opacities of various sizes and shapes that primarily affect the central cornea relatively early in life. Diagnosis is most often based on clinical appearance and careful biomicroscopic examination to assess the corneal layer(s) that are affected. Because most dystrophies are slowly progressive, visual acuity is often minimally affected for much of an individual's lifetime. Dystrophies are not associated with any prior corneal inflammations or systemic disease. This paper is a discussion of the most commonly encountered dystrophies affecting the epithelium, Bowman's membrane, stroma, and endothelium. The optometric management of many of these dystrophies may, at times, present a challenge to the clinician. Treatment may range anywhere from a simple therapeutic contact lens to referral for penetrating keratoplasty.

Contact Lenses↗
PubMed1988

Optic pit, microphthalmos and orbital cyst.

An orbital cyst was discovered by ultrasonography behind the globe of the left eye in a five-year-old boy with a left esotropia. In addition, an optic pit was present in the optic nerve head of the same eye, which was microphthalmic relative to the right eye. Although orbital cyst has been reported in the literature, this case is of interest because of the presence of two congenital anomalies in the same eye - namely, optic pit and orbital cyst. These two conditions have never been previously reported as existing together in the same eye.

Child, Preschool↗
PubMed1986

Visual evoked potential (VEP) delays in central serous choroidopathy.

The authors examined a series of ten consecutive patients with unilateral, idiopathic central serous choroidopathy. Visual acuities ranged from 20/20 to 20/70 during the active stage. VEPs were recorded to square sizes of 14, 28, and 56 min of arc. Overall, 90% of the patients had statistically significant VEP delays from the affected eye, while only 30% had statistically significant reductions in amplitude during the active stage. Six of the ten patients were reevaluated after the condition fully resolved. In all six, the VEP latency returned to normal. Although the mechanism of these VEP delays is not clear, their presence has been well documented. Therefore, a VEP delay in isolation of other tests should not be used in the differential diagnosis of macular vs optic nerve disease. One should specifically rule out macular disease in any patient with a delayed VEP before presuming the presence of a visual pathway dysfunction.

Adult↗
PubMed1985

Visual evoked potentials in macular disease.

Although a delayed visual evoked potential is considered to be the hallmark of optic nerve disease, relatively little has been published about VEP delays in macular disease. In this study, 20 patients with either acquired unilateral maculopathy or bilateral maculopathy in which one eye was more affected than the other were evaluated. VEP amplitudes and peak latencies were compared between eyes when recordable. Nine patients (45%) exhibited significant interocular delays in the affected or more affected eye while only four patients (20%) exhibited significant interocular attenuations in amplitude. In the nine patients exhibiting delays, three patients had a visual acuity of 20/30 or better in the affected eye or more affected eye. In the patients exhibiting amplitude attenuations, no patient had a visual acuity better than 20/50 in the affected or more affected eye. Although the mechanism of VEP delays in maculopathy is not clear, a VEP delay, in isolation of other tests, should not be used in the differential diagnosis of macular vs optic nerve disease. The clinician should specifically rule out macular disease in any patient with a delayed VEP before presuming the presence of a visual pathway dysfunction.

Adolescent↗
PubMed1984

Ocular manifestations of AIDS.

The acquired immunodeficiency syndrome (AIDS) is a devastating disease which continues to claim the lives of most of its victims. Despite the media's silence, AIDS has in no way disappeared. Over 4,400 cases have been reported thus far and many more new cases are reported each week nationwide. The ocular manifestations of AIDS should alert the doctor of optometry to the possibility of an AIDS suspect, especially if the patient is in one of the major risk categories. Early detection of this disease may permit more prompt treatment and thus a better prognosis for the AIDS patient.

Abducens Nerve↗
PubMed1982

Aeromonas hydrophilia: a rare and potentially life-threatening pathogen to humans.

The authors discuss the diagnosis, symptoms, and treatment of infections resulting from Aeromonas hydrophilia, and uncommon pathogen that is being reported with increasing frequency and may be serious to man. They present the case history of a 38-year-old male and emphasize the importance of prompt and proper treatment.

Accidents, Traffic↗
PubMed1981

The differential diagnosis of retinal disease from optic nerve disease.

Patients complaining of reduced acuity in the absence of a clearcut diagnosis present a challenge to the eye care practitioner. It is important to differentiate retinal disease from optic nerve disease as the etiology of the decrease in vision. This differentiation can have significant ramifications and must be determined for patient welfare and management. Several procedures may be used in making the differential diagnosis of macular or retinal from optic nerve disease. Some of these procedures are easy to perform and include Amsler grid, color vision testing, pupillary reflexes, light-brightness comparison, and macular dazzle. Other procedures require a greater degree of sophistication and include fluorescein angiography, the Visual Evoked Potential (VEP) and simultaneous VEPs and ERGs (Electroretinograms). The clinician should be aware of all of these procedures and how each may be useful in this differential diagnosis.

Color Perception Tests↗