Search PubMedSearch

Biomedical subjects

E C Campos

Publications and source records attributed to E C Campos.

At least 19 recordsLinked to original sources

Epikeratophakia: histopathological and cultural study.

Three epikeratoplasty buttons (one aphakic and two myopic) prepared by the freeze technique were removed two to nineteen months after surgery. A complete morphological and immunohistochemical study was performed on these buttons in order to gain insight into the reasons for epikeratophakia failure. Histopathological studies with light microscopy and scanning and transmission electron microscopy were performed. All three cases showed an anomalous process of re-epithelialization: in the first, the epithelium over the donor cap was almost completely absent, with many abnormalities; in the second, the epithelium was irregular, with a varying number of cell layers and poor adhesion between cells; in the third, the development of an epithelial cyst between the tissue lens and the cornea of the host caused the failure of the epikeratoplasty. The specimens were cultured 'in vitro' and the cells grown typed for HLA antigens. The antigen panel was the same as that of the host. Immunohistochemistry showed CD3- and CD8-positive cells in the stroma, proving the activity of T-suppressor lymphocytes in a cell-mediated immunoreaction.

Adult

Binocularity and photophobia in intermittent exotropia.

The relationship between photophobia and binocular function in intermittent exotropia was examined in 42 subjects (21 patients and 21 controls). In all subjects fusional amplitude and strength of binocular sensory status were tested before and during exposure to bright light. An explanation of photophobia in intermittent exotropia was suggested as impairment in binocular cooperation, since the indicators of binocular function were significantly altered in the patients, particularly during light exposure.

Adolescent

Recording of disparity vergence in comitant esotropia.

Vergence movements induced by base-out prisms were recorded, with an infrared eye movement recording system, in 5 patients with comitant esotropia and anomalous retinal correspondence and in 5 normal volunteers. The findings support the hypothesis that vergence movements in strabismus are induced by disparity, since accommodative as well as proximal vergence had been ruled out. Vergence movements are much slower and with different characteristics in strabismic patients with respect to normals. It may be argued that vergence movements represent the motor fusion component left over in strabismus. They may be considered the objective representation of the well-known phenomenon of prism compensation or adaptation, found in many strabismic patients.

Adolescent

Further evidence for the role of proprioception in space perception.

In this paper results are presented of errors in spatial localization found after encircling procedures for retinal detachment both in the operated and in the normal eye. Also changes in spatial localization were found in strabismus patients in which a stretch on the operated muscle was exerted after an adjustable recession. In both groups of patients a manipulation of the eye muscle was performed without inducing an eye muscle imbalance in the retinal detachment patients and without modifying the eye position in the strabismus patients in which a stretch was exerted. These data provide further evidence in favour of the role of proprioceptive information in space perception.

Humans

Amblyopia revisited: evidence for the heterogeneity of the syndrome.

Functional amblyopia has been considered as a homogeneous syndrome for the last decade or so, mainly on the basis of animal experiments. Recently, important differences have been shown to exist between strabismic and anisometropic as well as deprivation amblyopia. Even strabismic amblyopia may be subdivided in different classes. These statements are supported with experimental and clinical data. Clinical relevance of the heterogeneity of amblyopia is discussed particularly in the view of the concept of its cure.

Amblyopia

A new automatic computerized deviometer.

An automatized computerized deviometer is presented based on an infrared TV camera, an image analyzer and a computer. With this instrument it is possible to follow step-by-step the various diagnostic procedures in strabismus and to answer the following questions: is there a strabismus? is it convergent, divergent or vertical strabismus? what is the angle of deviation? which is the paralytic or paretic muscle in the case of incomitant strabismus?

Analog-Digital Conversion

Role of the central field in disparity-induced vergence movements in strabismus.

Disparity-induced vergence movements (fusional movements) were analyzed in esotropic patients by calculating the time required for compensation of a prismatic correction of their angle of deviation. The effect of central and peripheral field stimulation on these movements was studied by masking the central or the peripheral field. Both the center and the periphery were effective in triggering disparity-induced vergence movements. The center even seemed to prevail over the periphery. It is concluded that in comitant esotropia motor fusion is present not only in the periphery but also in the center, if appropriately tested.

Adolescent

Distance judgement in comitant strabismus with anomalous retinal correspondence.

Judgement of distances was evaluated in 19 patients with comitant esotropia and without appreciable stereopsis. In nine patients anomalous retinal correspondence (ARC) was present at Bagolini's striated glasses. In the remaining patients there was suppression with the same test. Distance judgement of strabismics with ARC does not differ statistically from that one of normals. Significantly different results were found in strabismics with suppression. It is concluded that ARC is not only an anti-diplopic mechanism, but provides the patients with useful clues in their daily life.

Adolescent

Abnormal spatial localization in patients with herpes zoster ophthalmicus. Evidence for the presence of proprioceptive information.

Patients with herpes zoster of the ophthalmic branch of the trigeminal nerve and normal ocular motility were examined. They were asked to point to targets without the sight of their own hand. Significant errors were found on the affected side. Proprioceptive information of the extraocular muscles is assumed to travel in the trigeminal nerve, and these results thus suggest the existence of peripheral afferent signals influencing eye-hand coordination.

Herpes Zoster Ophthalmicus

Functional differences between free alternators and non-alternators successfully treated for strabismic amblyopia.

Visual acuity was examined in patients successfully treated for strabismic amblyopia, and with equal refractive error in the two eyes (no more of 4 diopters of hyperopia). Patients able to freely alternate fixation showed equal visual acuity in the two eyes without optical correction. An optical correction in front of the ex-amblyopic eye was needed, in order to achieve equal visual acuity in patients unable to freely alternate fixation. No correction was necessary for the sound eye. This difference is attributed to a residual anomaly of accomodation of the ex-amblyopic eye. It is concluded that the concept of cure of strabismic amblyopia based on the attainment of equal visual acuity needs re-evaluation.

Accommodation, Ocular

Comparison of visual function studies in two cases of senile macular degeneration.

In this paper two relatively early cases of senile macular degeneration are compared by making use of a number of tests of visual function, some relatively new, coupled with observation of the fundus and analysis by fluorescein angiography. The functional tests include visual acuity, the sustainedlike and transientlike functions which are believed to test inner retinal receptive field properties and to have origin in the inner and outer plexiform layers, the Stiles-Crawford function which reflects the directional sensitivity and orientation of photoreceptors, and increment threshold curves. In one case there was evidence of inner retinal involvement at the time the tests were conducted, but, because the Stiles-Crawford function remained essentially normal, it is assumed that the receptors were not disturbed relative to their orientation. In this case (as in many others), the zone or area exhibiting functional change does not necessarily match the area exhibiting anatomical change as observed by examination of the fundus, fundus photography, and fluorescein angiography. In the second patient there is evidence of both anomalous inner retinal function and disturbance in receptor alignment. The later suggests disorientation of the receptor bed. These findings correlated with the fundus observation and fluorescein angiographic evidence of a leak, resulting in the presence of serous fluid beneath the neurosensory retina. With resolution of this fluid there was a return of the functional tests toward normal. At this time, it is not possible to determine whether, in two cases, the functional changes are proceeding on a parallel course, but are at different stages, or whether they are the expression of somewhat different anomalies.

Aged

Visual resolution in a patient exhibiting a visual fatigue or saturation-like effect: probable multiple sclerosis.

A rapid visual resolution test conducted on available equipment reveals the presence of rapid falloff in acuity in a case of probable multiple sclerosis. Intense large field illumination was used, and grating acuity was tested using laser red light. The effect is so large that minor anomalies (not subjectively appreciated) or the residuum of earlier minor attacks of retrobulbar optic neuritis can be readily detected. A related "visual fatigue or saturation-like syndrome" was described earlier. In bright environments these patients' vision fades. Briefly closing the eyes restores visual sensitivity. Providing filters or lowering the light level tends to maintain vision. This test must be studied intensively. It offers a noninvasive simple means of showing underlying anomalies in neural conduction of the visual signal. Such anomalies can be prognostic and previously have been revealed only with sophisticated electrophysiological techniques.

Adult

Measurement of visual resolution at high luminance levels in patients with possible demyelinating disease.

An interferometric acuity device (Takata) has been used to study visual resolution in individuals with possible demyelinating disease. The instrument employed provides a large field with a continuous range of grid or fringe frequencies and a relatively intense (10(5) mean photopic trolands) stimulus. After a brief period of time with eyes closed, resolution thresholds of patient are repeatedly determined during a five minute period. In all individuals suspected of having a demyelinating disease tested to date, a fall off in resolution capability has been found in time when using this intense stimulus display. This occurs whether eye signs have been present, are present or have not yet been observed. Normal observers do not exhibit comparable decrements. The fall off in resolution capability may or may not occur at lower stimulus levels, and is often not revealed when testing routine Snellen acuity. Outer and inner retinal pathology (division based on vascular support) do not cause a comparable fall off in resolution in time. The interferometric acuity test is a non-invasive, easily applied test.

Adult

Some functional abnormalities in amblyopia.

In discussing the relationship between anomalous retinal correspondence and amblyopia, it is suggested that amblyopia may be due not only to suppression and/or non-use of the deviated eye, but also to a mis-use of this eye. The interaction of the 'focal' and 'ambient' systems in amblyopia and the relationship of the 'ambient' system to the interocular transfer of the motion after-effect are discussed. This effect has been found to be of no clinical significance in predicting the presence or absence of binocular cooperation. It is concluded that in cases of amblyopia there is either no disturbance in the 'ambient' system or an adaptation of the latter to the pathological condition.

Adolescent