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Biomedical subjects

G Tillson

Publications and source records attributed to G Tillson.

18 recordsLinked to original sources
PubMed1992

Neurodevelopmental criteria in the classification of congenital motor nystagmus.

Congenital motor nystagmus (CMN) can be familial or non-familial. The expressivity of CMN is so variable that in one affected member of the family the oscillations are obvious, while in the others the nystagmus could be overlooked even by the patients themselves. In spontaneous cases the proof of heredity might be discovered by an ophthalmological examination or eye movement recordings of other family members. Our multidisciplinary studies of 27 children with CMN suggests that a neurodevelopmental assessment can also be valuable in establishing a diagnosis of heredity. Our studies suggest that the hereditary form of CMN is free from neurodevelopmental problems, while the non-familial form is not. Therefore, children with spontaneous CMN could be referred for neurodevelopmental evaluation in order to establish a more accurate diagnosis.

Adolescent↗
PubMed1989

Intractable diplopia after vision restoration in unilateral cataract.

Twenty-four patients lost their ability to fuse when their binocular function was disrupted for at least 2 1/2 years by a unilateral traumatic cataract or a unilateral traumatic cataract followed by uncorrected aphakia. Three patients were 6 years old, one was 8 years old, and the remaining 20 patients were aged 10 years or older at the time of the injury. All patients had intractable diplopia when the cataract was removed and the aphakia corrected. Aniseikonia was not the cause of this inability to fuse and the insertion of an intraocular lens provided no relief. The prognosis for the elimination of diplopia, other than by occlusion of one eye, was poor.

Adolescent↗
PubMed1988

The loss of fusion in adults with intractable diplopia (central fusion disruption).

People over the age of 10 years can lose their fusion ability. This acquired disruption of fusion gives rise to intractable diplopia without suppression. An involuntary vertical bobbing movement of the non-fixing eye, present only with both eyes open, occurs at or near the angle of superimposition. This appears to be a unique and characteristic sign of acquired disruption of fusion and was present in all cases. Other causes of diplopia are mentioned and differentiated. Acquired central fusion disruption usually results from serious head injury. Partial recovery may occur but is unlikely. Sensory deprivation of at least 3 1/2 years' duration due to poor vision in one eye resulting from a traumatic cataract and sometimes subsequent uncorrected unilateral aphakia caused loss of fusion in 15 patients. The practical implications with regard to intraocular lenses and unilateral aphakia is discussed. Less commonly, vascular, neoplastic and presumed inflammatory lesions in the mid-brain area cause central fusion disruption.

Adult↗
PubMed1988

Supranuclear disturbances of ocular motility in Lytico-Bodig.

We found abnormal supranuclear ocular or lid motility in all of 37 patients with Lytico-Bodig (amyotrophic lateral sclerosis/parkinsonism-dementia complex). Twenty-one patients had pursuit paresis, 18 abnormal vestibulo-ocular reflex (VOR) cancellation, 15 abnormal convergence, 13 abnormal optokinetic nystagmus (OKN), 12 conjugate gaze limitation, nine nystagmus, nine saccadic paresis, and six abnormal fixation. Lid abnormalities included glabellar hyperreflexia in 21, involuntary levator inhibition in three, and blepharospasm in two. Earlier reports have indicated infrequent ocular disturbances in Lytico-Bodig, but we now find supranuclear eye and lid deficits are universal and sometimes very prominent.

Aged↗
PubMed1984

Suppression in strabismus--an update.

Previous reports have described suppression scotomas, suppression varying with the type of strabismus and suppression confined to one half of the retina (hemiretinal suppression). Our findings show that suppression in all varieties of strabismus, with the exception of the monofixation syndrome, involves the whole of the visual field of the deviating eye except for its monocular temporal crescent. In the monofixation syndrome our findings show a small central suppression scotoma involving the fovea but leaving the rest of the visual field of the deviating eye unsuppressed. We could find no evidence to support the concept of hemiretinal suppression but found evidence to support the presence of a trigger mechanism for suppression which operates on a hemiretinal basis.

Depth Perception↗
PubMed1984

Sensory outcome with nonsurgical management of esotropia with convergence excess (a high accommodative convergence/accommodation ratio).

Twenty-seven patients with esotropia and convergence excess (a high accommodative convergence/accommodation [AC/A] ratio) managed nonsurgically underwent a final standardized evaluation of their sensory and motor status after a follow-up period of at least 8 years. All had a deviation with distance fixation of less than 10 prism dioptres (PD) of esotropia with full optical correction both initially and throughout the follow-up period. The average spherical-equivalent refractive error was +2.3 D. The AC/A ratio had tended to decrease with age, and most patients had fusion, although only a small proportion had central fusion and stereopsis. Approximately half of the patients had been treated with bifocals, but their sensory outcome did not differ from that of the other patients. Miotics had not been used for more than a few months in any patient, as they were ineffective in reducing the deviation with near fixation to less than 10 PD of esotropia. A study, possibly a multicentre one, involving larger numbers of patients should be designed to find out whether bifocal therapy offers an advantage in the final sensory outcome of such patients.

Accommodation, Ocular↗
PubMed1983

Suppression in strabismus and the hemiretinal trigger mechanism.

A perimeter and a modified Lees screen were used to determine the area of visual field that is suppressed in strabismus. Strabismic patients without fusion suppress the whole area of the visual field of the deviating eye that could have correspondence with the dominant eye. In the monofixation syndrome, suppression only involves the fovea and the diplopic point of the deviating eye. Diplopia, if present, is appreciated throughout the visual field shared by the two eyes, except for the blind spots. No evidence of hemiretinal suppression was found in any type of horizontal strabismus, including exotropia. However, there is a hemiretinal trigger mechanism for suppression. Once suppression has been triggered by this mechanism, it involves the whole visual field of the deviating eye, except for the monocular temporal crescent.

Adolescent↗
PubMed1983

Sensory results following treatment of infantile esotropia.

Forty patients with infantile esotropia were treated by one ophthalmologist and followed up for 5 to 14 years. In all cases the initial surgery was performed by the age of 2 years, 4 months. The angle of deviation was reduced to within 10 prism diopters of orthotropia in 34 patients, and in 26 of them the reduction was maintained. However, only 6 of the 26 with a stable reduction showed evidence of binocular function by both troposcopic evaluation and the Wirt stereo test. Dissociated vertical divergence, nystagmus and amblyopia were much more common among the patients in whom fusion did not develop and may be the cause of this failure.

Child↗
PubMed1981

Visual results after removal of congenital cataracts before the age of 1 year.

Six patients underwent removal of congenital cataracts (Unilateral in three and bilateral in three) from otherwise normal eyes in the first year of life. Good corrected vision, including 6/9 in one of the unilateral cases, was obtained in each aphakic eye. A more aggressive approach to eliminating the sensory obstacles to seeing should include the removal of dressings 1 day after the operation, the use of soft, permanent-wear contact lenses within a few days thereafter and reduction of the time between the operations on bilateral cataracts to 5 days. In unilateral cases an occlusive patch must always be worn over the normal eye 90% of the waking day, even during illnesses.

Age Factors↗
PubMed1980

A pilot study of children with amblyopia treated by the gratings method.

A total of 6 patients, 2 with anisometropic, 2 with strabismic and anisometropic, and 2 with strabismic amblyopia treated with the 'gratings method' showed more than 2 lines of improvement in linear visual acuity. Patient attention and interest and repeated testing of the visual acuity were uncontrolled factors in this study. Moreover, the detailed visual tasks performed by the amblyopic eye may in themselves be the reason for improvement. Clearly a careful study which controls these possibilities is needed before a claim can be made that the 'gratings' per se offer an improved method of treatment of amblyopia.

Amblyopia↗
PubMed1979

Acquired central disruption of fusional amplitude.

Acquired central disruption of fusional amplitude is characterized by a complete loss of fusional amplitude, the patient maintaining fusion for only a moment under test conditions before breaking to constant diplopia. Under normal viewing conditions, the patient has constant diplopia with both eyes open. Patients who have bilateral superior oblique palsy may mimic this loss of fusion and constant diplopia, but they are distinguished by fusing readily on the troposcope, which compensates for the excyclotorsion, in contrast to prisms, which do not remove the double vision. Case reports document an association with convergence palsy, an infranuclear unilateral superior oblique palsy, and a nonparetic acquired strabismus in visual adults. Head trauma is the usual cause.

Adult↗
PubMed1979

Prismotherapy in intermittent exotropia. A preliminary report.

Twenty-five patients with intermittent exotropia and suppression were prescribed prisms which neutralised their maximum deviation. Thirteen patients failed to wear their prisms properly and served as controls and none were cured. Eight of the 12 patients who wore their corrective prisms more than half the time they were awake were cured.

Child↗
PubMedDate not supplied

Hard contact lenses in the management of congenital cataracts.

This paper describes our experience with 54 eyes which were optically corrected with polymethylmethacrylate hard contact lenses following the removal, in infancy, of a congenital cataract. The lenses were tolerated well, few alterations were required and the majority of patients did not lose more than one lens a year. Our results show that it is possible to obtain visual acuity of 20/25, in unilateral congenital cataract cases.

Cataract↗
PubMedDate not supplied

The management of esotropia with high AC/A ratio (convergence excess).

This paper reviews the long-term follow-up of esotropia with a high AC/A ratio defined as an increase of 20 delta or more of the esotropia at near compared with distance with the full optical correction of any refractive error in place. Ninety-nine patients were studied for an average follow-up of eight years. Eighty-six achieved fusion but only five achieved central fusion. Forty-five were treated with bifocals. No significant difference in the sensory results were recorded in those patients wearing bifocals compared with those who did not wear bifocals. No patient had miotic therapy for more than a few months. The suppression characteristic of this condition is reviewed.

Child, Preschool↗
PubMedDate not supplied

The investigation and management of torsion preventing fusion in bilateral superior oblique palsies.

Fifteen patients with bilateral superior oblique palsy were studied with respect to the influence of torsion on fusion with amplitudes. The Clement Clarke synoptophore was used to record torsion and examine fusion. Nine patients needed the correction of torsion preoperatively to fuse in the primary position. Three patients had central fusion disruption. Torsion in excess of 10 degrees or bilateral excyclotorsion were present in most patients who required torsion correction for fusion with amplitudes. All patients had surgery. The effects, at least three months after surgery, are discussed. Some residual excyclotorsion remained in most cases and appears to be compatible with a good fusional result and an average field of single binocular vision of 30 degrees.

Adolescent↗
PubMedDate not supplied

Unilateral congenital cataract: binocular status after treatment.

We describe the binocular status of four patients, aged 5, 6, 10, and 13 years, who had a unilateral congenital cataract removed in the first few months of life. A contact lens had been fitted in all cases and was worn continuously. The normal eye was occluded for approximately 90% of the waking day until at least the age of 4 years. Two patients developed an esotropia and two an exotropia. Best-corrected visual acuity is 20/40 or better in both the aphakic and the normal eye. The patients' binocular status was assessed with a full eye examination, tests for fusion in free space with prism neutralization, tests for stereopsis, and examination on the Clement Clarke synoptophore. All patients showed simultaneous perception but no real fusion, resulting in diplopia. A vertical bobbing effect was noted at the angle of neutralization similar to that reported by us in cases of central fusion disruption.

Cataract↗