Biomedical subjects

I Gottlob

Publications and source records attributed to I Gottlob.

At least 19 recordsLinked to original sources

PubMed1995

Visual acuities and scotomas after 3 weeks' levodopa administration in adult amblyopia.

BACKGROUND: Previous studies have shown that both a single dose of levodopa and a 1-week administration of levodopa improve visual functions in adult amblyopic patients. In the present study, we investigated the effect of increased dosage and duration of levodopa on amblyopes' visual functions. METHODS: Visual acuity and visual fields were examined before and after 3 weeks of daily administration of levodopa/carbidopa as well as 1 month and 2 months after completion of drug therapy in a double masked-design. RESULTS: A significant increase in visual acuities and a decrease in fixation point scotomas were found. Changes were of comparable dimension to those found after 1 week of levodopa administration. Improvement of visual functions persisted 2 months after the levodopa/carbidopa administration was completed. CONCLUSION: The present study confirms previous findings of improvement in visual function in amblyopia after levodopa/carbidopa administration. However, increasing the dosage and the duration of levodopa did not enhance the effect in adults.

Administration, Oral↗

PubMed1995

Quantitative eye and head movement recordings of retinal disease mimicking spasmus nutans.

PURPOSE/METHODS: To investigate whether quantitative head and eye movement recordings can distinguish patients with spasmus nutans from patients with retinal diseases mimicking spasmus nutans. A patient with congenital stationary night blindness was followed up for seven years with electro-oculographic eye movement recordings. RESULTS/CONCLUSIONS: Rhythmic head movements and fine, intermittent, asymmetric, disconjugate, high-frequency, out-of-phase pendular nystagmus were recorded. Eye and head movement recordings of patients with congenital stationary night blindness can mimic spasmus nutans.

Electrooculography↗

PubMed1995

Spasmus nutans. A long-term follow-up.

PURPOSE: Nystagmus, head nodding, and anomalous head position are symptoms of spasmus nutans. This disorder appears in early childhood and is thought to be self-limited. However, the visual outcome of patients with spasmus nutans is unclear. The resolution of nystagmus has not been proven with quantitative eye movement recordings. The purpose of this study was to perform long-term follow-up examinations (mean, 5.5 years) of patients with spasmus nutans. METHODS: Ten patients with spasmus nutans were followed up clinically until a mean age of 7 years. Included were quantitative eye and head movement recordings. RESULTS: At their last examination (mean age, 7.1 years), visual acuity in four patients was 20/20 in both eyes, in five patients it was 20/30 or better in at least one eye, and in one patient it was 20/50 in each eye. Three patients had orthotropia with normal stereo acuity. The remaining patients had esotropia, dissociated vertical deviation, amblyopia, or latent nystagmus. All patients had fine, intermittent asymmetric, pendular nystagmus on eye movement recordings. CONCLUSIONS: Good visual acuity can be expected in patients with spasmus nutans; one third have normal stereo acuity. However, subclinical nystagmus persists until at least 5 to 12 years of age.

Child↗

PubMed1994

Eye and head movements in patients with achromatopsia.

The diagnosis of patients with rod monochromatism (RM) and blue-cone monochromatism (BCM) may be difficult. The relative direction and symmetry of nystagmus of the two eyes, as well as the existence or nature of rhythmic head movements, are not known. We analyzed simultaneous eye and head movement recordings of 16 patients with RM and three patients with BCM. Longitudinal examinations were performed in seven patients. Younger patients had pendular, intermittent or continuous oblique nystagmus with both eyes oscillating in phase or out of phase with equal amplitudes. Older patients had continuous symmetrical oblique jerk nystagmus with decreasing velocities in the slow phase. In two children, we demonstrated evolution from pendular to predominantly jerk nystagmus. Rhythmic head movements were detected in all children. Patients with RM and BCM exhibit a distinct entity of nystagmus and can be differentiated from patients with congenital or latent nystagmus. However, eye and head movements can mimic spasmus nutans.

Adolescent↗

PubMed1994

Effect of levodopa on the human dark adaptation threshold.

BACKGROUND: In several species there is strong evidence that the retinal dopamine turnover is influenced by retinal dark and light adaptation. In the human retina, dopamine has been found in amacrine and interplexiform cells. METHODS: In the present study, the influence of orally administered levodopa on the human dark adaptation was investigated in healthy subjects using the Goldmann-Weekers adaptometer. To exclude effects of levodopa on the pupil size, a second group was examined after pupil dilation before each examination. A third and fourth group were examined under the same conditions as the first two groups, but without levodopa administration. RESULTS: Levodopa caused a uniform threshold elevation throughout dark adaptation with undilated and dilated pupils. No effect on sensitivity was observed in the control groups. CONCLUSION: These results show a dopaminergic reduction in sensitivity during human dark adaptation.

Administration, Oral↗

PubMed1994

Eye movement abnormalities in carriers of blue-cone monochromatism.

PURPOSE: Although impaired color vision and ERG changes have been detected in carriers of blue-cone monochromatism (BCM), no eye movement abnormalities have been identified. Quantitative eye movements of three obligate carriers of BCM were analyzed. METHODS: Horizontal and vertical eye movements of three obligate carriers of two families with BCM with visual acuity of 20/20 or better were recorded using the magnetic search coil technique. Subjects were examined fixing in primary and eccentric gaze and during horizontal and vertical smooth pursuit at 20 degrees, 40 degrees, and 80 degrees per second. RESULTS: All carriers displayed fixation instability. In two subjects, fine-amplitude upbeat, jerk-type nystagmus was detected. Reduced pursuit gain was found in the carriers. The third subject had small downbeat nystagmus. CONCLUSION: Abnormal eye movements are described for the first time in carriers of BCM. The nystagmus is clearly distinct from congenital or latent nystagmus and is similar to the nystagmus reported in BCM. Because all carriers had excellent visual acuity, in BCM, nystagmus is intrinsic to the disease and can appear independently of the visual defect.

Adult↗

PubMed1992

Visual remapping in infantile nystagmus.

The possibility that patients with idiopathic infantile nystagmus achieve spatial constancy by visual remapping was investigated by comparing subjective localization of flashed test targets to their absolute position in space and to their absolute position on the retina. Nystagmats first viewed a screen-stationary reference target that was followed by a test flash. A computer used eye movement feedback to precisely control the test flash position on the retina. All six nystagmats detected test flashes throughout their nystagmus cycle. For three nystagmats test flashes (total N = 48) were delivered to the same retinal locus that were, at different times, to the right and left of the reference target. More than two-thirds of such crossover stimuli were correctly located in space: when only those stimuli at least 0.5 deg from the reference were considered, two of three subjects correctly located all stimuli. Taken together these results argue that our subjects could see throughout the nystagmus cycle and shifted their visual map in synchrony with their nystagmus as an explicit means of avoiding oscillopsia.

Adolescent↗

PubMed1992

Head nodding is compensatory in spasmus nutans.

BACKGROUND: Spasmus nutans is defined as asymmetric nystagmus with associated head nodding in childhood. It is not clear whether head nodding is a compensatory mechanism to control the nystagmus or an involuntary movement of pathologic origin. METHODS: The authors analyzed the relation between head and eye movements by simultaneous eye and head movement recordings of 35 patients with spasmus nutans. RESULTS: In 21 of these patients, the fine, fast, dissociated nystagmus changed during head nodding to larger and slower symmetric eye movements with both eyes oscillating at the same amplitude in phase and 180 degrees out of phase to the head movements, corresponding to a normal compensatory vestibulo-ocular reflex. CONCLUSION: These findings indicate that head nodding is compensatory in spasmus nutans.

Child, Preschool↗

PubMed1992

Visual acuities and scotomas after one week levodopa administration in human amblyopia.

The authors previously showed that a single dose of levodopa improves the contrast sensitivity and decreases the size of fixation point scotomas in amblyopic patients. In the present study, they investigated the effect of levodopa after 1 wk of daily administration using a cross-over, double masked design. The decrease of fixation point scotomas was confirmed with automatic static perimetry. An improvement of visual acuity occurred in 70% of the patients after 1 wk of levodopa administration compared to only 22% in the authors' previous study using one single dose. The improvements in visual acuities and visual fields persisted even after the levodopa administration was completed.

Administration, Oral↗

PubMed1991

Visual-evoked cortical potentials in dissociated vertical deviation.

It is debatable whether chiasmatic misrouting of temporal optic-nerve fibers (similar to that found in ocular albinism) is also characteristic of dissociated vertical deviation. Pattern appearance, pattern reversal, and diffuse-flash, monocular full-field visual-evoked cortical potentials were recorded from albino and normal human subjects and subjects with dissociated vertical deviation. Pattern appearance was the most reliable stimulus for evaluating lateralization (albino-type misrouting) in adult albino patients, and diffuse-flash stimulation was almost as reliable in children. Pattern reversal was found to be an unreliable indicator. Lateralization was not evident among patients with dissociated vertical deviation, as determined by the three modes of stimulation. Our data supported earlier findings that pattern appearance is the most appropriate technique to detect lateralization. Our findings differed from those of previous reports in demonstrating that reliability of the lateralization phenomenon increases with age up to approximately 15 years. Pattern reversal stimulation was not reliable in patients with horizontal nystagmus.

Adolescent↗

PubMed1991

Surgical management of oculomotor nerve palsy.

We treated seven patients with unilateral oculomotor nerve palsy by transposition of the insertion of the superior oblique tendon to a point anterior and medial to the insertion of the superior rectus muscle without trochleotomy (Scott procedure). Additionally, large recessions of the lateral rectus muscle of involved eyes and, occasionally, recess/resect procedures of horizontal recti muscles of non-involved eyes were performed. All patients were followed up between one and eight years. Orthophoria in the primary position was achieved and maintained with one operation in four patients. A fifth patient had only a small residual exotropia. In two patients who had aberrant regeneration of the oculomotor nerve, surgery on horizontal recti muscles of the noninvolved eye improved the eyelid position of the involved eye after three operations.

Blepharoptosis↗

PubMed1991

Pattern electroretinogram and luminance electroretinogram in Alzheimer's disease.

Visual symptoms are often among the first complaints of patients suffering from Alzheimer's disease and several studies showed a delay in flash visual evoked potentials. Hinton et al. (1986) described optic nerve degenerations in patients with Alzheimer's disease and Sadun published a dropout of retinal ganglion cells that range from 30% to 60%. The reduction of neurotransmitters, especially of acetylcholine, found in the brain might also occur in the retina. Therefore we examined the retinal functions of patients suffering from Alzheimer's disease. In eight patients the pattern-electroretinograms and the scotopic and photopic luminance-electroretinograms were recorded and compared to an age-matched control group. We could not find any abnormalities in the pattern- and the luminance electroretinograms of patients with Alzheimer's disease. Although cholinergic cells have been found in the retina, our results did not reveal an involvement of retinal functions in Morbus Alzheimer.

Aged↗

PubMed1990

Treatment of manifest latent nystagmus.

Eight patients with manifest latent nystagmus, as noted by ocular movement recordings, were examined for nystagmus reduction after surgical or optical treatment. Seven of the patients had strabismus. Five patients underwent strabismus surgery, had no tropia postoperatively, and the manifest latent nystagmus converted to latent nystagmus. Four of these five patients subsequently showed improvement in binocular visual acuity. Three patients received optical treatment; one had accommodative esotropia and, with appropriate spectacle correction, the manifest latent nystagmus was converted to latent nystagmus with improved vision. In the other two patients the manifest latent nystagmus lessened after correction with appropriate spectacles; binocular visual acuity of one of these patients improved. The possibility of converting manifest latent nystagmus to latent nystagmus by strabismus surgery is a reasonable surgical goal. In patients with manifest latent nystagmus and strabismus, surgical or optical alignment of the eyes decreases the nystagmus intensity and may also improve binocular visual acuity.

Adolescent↗

PubMed1990

Signs distinguishing spasmus nutans (with and without central nervous system lesions) from infantile nystagmus.

Clinical findings as well as eye and head movement recordings were analyzed from 23 patients with spasmus nutans without central nervous system (CNS) changes, 10 patients with spasmus nutans-like disease (head nodding, intermittent nystagmus associated with intracranial anomalies or visual pathway disorders), and 25 patients with infantile nystagmus. Ten diagnostic signs were established to differentiate between the patient groups. Although they were helpful in separating patients with infantile nystagmus from those with spasmus nutans, no difference was found between the patients with spasmus nutans with and without CNS lesions. This study indicates that eye and head movement recordings do not allow differentiation between benign spasmus nutans and spasmus nutans-like disease. The differentiation must be made on the basis of neuroimaging.

Child↗

PubMed1990

Effect of levodopa on contrast sensitivity and scotomas in human amblyopia.

The neurotransmitter dopamine (DA) is involved in several visual functions. Visual deprivation decreases retinal DA concentration in chickens and monkeys. In animals with deprivation amblyopia, several studies suggest that neurotransmitters are involved in visual-cortical plasticity and can restore partial visual acuity in adult cats. We investigated in a cross-over, double-masked study the influence of levodopa on contrast sensitivity and binocular suppression in human adult strabismic and amblyopic patients. After one single administration of levodopa, a significant increase in contrast sensitivity and decrease of the size of the fixation point scotoma was found. No changes could be detected after placebo administration. Levodopa did not induce changes in contrast sensitivity in the dominant eyes of the patients or in normal subjects. In conclusion, we found a short-term effect of levodopa on contrast sensitivity and fixation point scotomas in amblyopic eyes of adult patients.

Adult↗

PubMed1990

Effect of levodopa on the human luminance electroretinogram.

Scotopic and photopic electroretinograms (ERGs) were recorded in 12 healthy volunteers before and 90 and 180 min after administration of levodopa. After 90 min the drug significantly increased the scotopic ERG b-wave amplitude and implicit time. The dark-adapted oscillatory potentials (OPs) were selectively affected, while no changes were observed in the photopic ERG. Levodopa had no effect on the ERG after 180 min drug applications. As a control, the experimental procedure was repeated without drug administration, and no changes were observed.

Adult↗

PubMed1989

Reversible changes of visual acuity and pattern-electroretinograms after blue-green argon laser photocoagulation of diabetic patients.

Visual acuity, color vision, pattern-visual-evoked-potentials (P-VEPs) and pattern-electroretinograms (P-ERGs) were measured in 13 diabetic subjects before, and 24 hours and 5 weeks after blue-green argon laser treatment. As control, the same examinations were performed in 7 normal subjects and 7 diabetic patients before and after slit lamp examination with the Goldman three mirror contact lens. Visual acuity and P-ERG amplitudes were significantly reduced one day after the laser treatment, while 5 weeks after the laser coagulation, visual acuity and P-ERG amplitudes recovered to pretreatment values. The control group showed no significant changes after slit lamp examination. Since fluorescein angiography revealed no macular changes after laser treatment, the possibility of a reversible functional light damage after blue-green argon laser coagulation (ALC) is discussed.

Aged↗

PubMed1989

Comparison of contrast sensitivity between posterior chamber lenses of silicone and PMMA material.

Seventeen patients received a posterior chamber lens of PMMA in one eye and a silicone lens (Staar Surgical Co.) in the other. Contrast sensitivity was examined in both eyes in order to detect differences with respect to the material used for lens implantation. An attempt was made to exclude any changes in the eyes that were not due to lens implantation and that might possibly have an influence on the result. A paired T-test was performed for each spatial frequency. No statistically significant difference was found between the two materials with regard to contrast sensitivity.

Aged↗