Changes in refraction in anisomyopic patients.

PURPOSE: The purpose of this study was to investigate the evolution of refraction and visual function in patients with myopic anisometropia. DESIGN: A retrospective study on a selected population. METHODS: Forty-six anisomyopic patients underwent a complete ophthalmologic examination (cycloplegic refraction, visual acuity, ocular movement and fundus examination). RESULTS: The results show two different patterns of changes in refraction between the two eyes; in the same patient, the less myopic eye tends to get more myopic, while the more ametropic eye shows a more stable refraction. Furthermore, a recovery of binocular vision and amblyopia can be obtained by occlusion and full-time refractive correction. CONCLUSIONS: The evolution of refraction seems to be different in eyes with anisometropia and it is still to be understood whether it is fixation or reduced fixation that leads to a myopic shift.

[The epidemiological aspects of eye screening in occupational medicine]. / Considerazioni epidemiologiche sullo screening oculistico in medicina del lavoro.

The wide-spread use of video display units in many work places has led to an increase in ophthalmologic examinations of the operators. For this reason, instruments for visual test screening (for example Visotest) have become widely used. Nevertheless, the literature does not seem to offer any clarification about the utility of these instruments as epidemiological tools. The costs and benefits of visual screening programmes were estimated in relation to specific visual deficit prevalence in a differently age-structured population. Via epidemiological calculation, it was demonstrated that positive and negative predictive values, which are directly related to deficit prevalence, are more important than sensitivity and specificity calculations. In view of the disorders screened, a visual test with a low positive predictive value is more expensive than one with a low negative predictive value. A visual test for visual deficits screening does not appear to be advisable in young populations, where the true positives/false positives ratio is 1:4, whereas in older populations the ratio is 2:1.

[Electrophysiological studies in amblyopia]. / Badania elektrofizjologiczne w niedowidzeniu.

The authors describe the methods of recording the visual evoked potentials and of their utilization for investigations in amblyopia. The characteristics of VEP have been analyzed in an amblyopic and a normal eye; analyzed further on were the reciprocal dependencies between an uniocular and binocular records, the phenomenon of suppression and sensitivity to contrast. The authors confirm the suitability of the VEP for objective evaluation of the progress of treatment and for elucidation of the physiopathology of amblyopia.

[Placoid pigment epitheliopathy: a parallel study between automatized perimetry and fluorescence angiography]. / Epithéliopathie en plaques: parallèle entre la périmétrie automatisée et l'angiographie en fluorescence.

This report concerns a patient whom, on the basis of clinical data and instrumental findings, we diagnosed as suffering from Acute Multifocal Posterior Pigment Epitheliopathy (AMPPE). We found the comparison of the angiographic findings and of the automated perimetry performed with the Octopus quite interesting since the literature does not contain reports of such comparisons. The results of perimetry were also of considerable interest. The test revealed serious impairment of retinal luminous sensitivity. The comparison of angiography and automated perimetry of the lesions of the pigmented epithelium was quite useful for providing a better clinical picture and understanding of the functional state.

The influence of early diabetes on the pattern electroretinogram.

Pattern electroretinogram response and contrast sensitivity were evaluated in two groups of diabetic patients by means of psychophysical and electrophysiological methods. The first group consisted of subjects suffering from diabetic retinopathy in various stages of evolution; the second was composed of diabetic patients with no fundus alterations and with good visual acuity. In both groups of patients, when the pattern electroretinogram was altered, contrast sensitivity was also abnormal.

Visual involvement in Friedreich's ataxia: PERG and VEP study.

Neuro-ophthalmological assessment, including red-free light retinography, in conjunction with simultaneous visual evoked potential (VEP) and pattern electroretinogram (PERG) recordings were performed in 10 Friedreich's ataxia patients: 9 patients showed marked VEP abnormalities. Moderate PERG amplitude reduction, with normal latencies, was related to mild and scattered fiber loss revealed by red-free light retinography. The initial part of the visual pathways does not seem to be the main site of electrophysiological abnormalities as demonstrated by the greater extent and relative independence of VEP versus PERG alterations. Primary axonal degeneration of the optic nerve and tracts cannot account for all features of VEP abnormalities, thus implying some dysfunction in succeeding visual structures as well.

[Elevation in adduction. Relation to congenital strabismus and other types of ocular motility disorders]. / L'élévation en adduction. Rapports avec le strabisme congénital et avec d'autres types de troubles de la motilité oculaire.

This retrospective study shows the clinical data of 81 patients with elevation in adduction. The relationships between the elevation in adduction and various ocular anomalies, such as horizontal deviations, refractive errors, nystagmus, torticollis, superior oblique muscle paralysis and dissociated vertical deviation, have been studied in order to specify the clinical characteristics of this phenomenon. The age of onset of the elevation in adduction and of the dissociated vertical deviation has also been considered, and a typical temporal progression of these symptoms has been found. In this sequence, we first noticed the onset of the horizontal deviation, then the appearance of the elevation in adduction, and finally the appearance of the dissociated vertical deviation. Although the elevation in adduction is frequently found in association with the complex syndromic pattern of congenital esotropia, this phenomenon may also accompany other types of anomalies of ocular motility.

Electrophysiological studies of the visual system in myotonic dystrophy.

Ocular signs and electroretinal alterations frequently occur in Myotonic Dystrophy (MD). Surprisingly few reports describe VEP abnormalities for this syndrome. Since the evaluation of cortical visual responses is linked to an understanding of preceding retinal changes, we conducted a systematic study of the visual system including ophthalmological and electrophysiological (EOG, ERG, PERG, VEP) investigation in 14 confirmed myotonic patients. The various tests revealed consistent abnormalities, the most frequent of these being PERG and VEP changes. These alterations seemed to occur independently of one another, suggesting impaired function at different levels of visual pathway. A generalized defect of cell membrane has recently been proposed as etiopathogenesis of typical EMG and systemic features of the disease. Such membrane dysfunction might account for the early and marked abnormalities in electrophysiological tests, even in the absence of neuro-ophthalmological changes.

Visual evoked potentials and CSF IgG at different stages of multiple sclerosis: a possible correlation.

Visual Evoked Potentials (VEP) have been investigated in 102 patients affected by Multiple Sclerosis (MS), classified both by disease stage and by optic pathway status. VEP abnormalities were significantly correlated with the clinical stage and increased CSF IgG levels. The delay in the VEP latencies and the CSF IgG values proved to be increased in parallel in the worsening phases of MS. The diagnostic value of these findings is also discussed.

Contribution of computerized tomography to the study of severe congenital ocular dysplasias. Study of a case of clinical anophthalmos.

The present report summarizes the results of a study by computerized tomography (CT) in a child suffering from congenital bilateral anophthalmos and slight mental deficiency. The CT images suggest that this case can be classified as primary anophthalmos. We report a case of suspected congenital bilateral anophthalmos whom we investigated by computerized tomography (CT). A thorough examination of the brain and intraorbital contents was carried out.

[Focosi's tendon-lengthening technic in blockage syndromes. Mechanism of action and surgical technic]. / L'allongement du tendon selon Focosi dans les syndromes de blocage. Mécanisme d'action et technique chirurgicale.

114 subjects with esotropia and blockage syndrome were observed. Diagnosis was based upon clinical and EOGraphical data. Tendon lengthening with fascia lata was performed mono or bilaterally on medical recti, with or without associated resection of the external recti. The residual angle of strabismus and the effect on the blockage were measured to evaluate the results. Those seemed to be generally favourable. The AA. discuss upon the action of this kind of surgery on the muscular dynamic.

Current views and some suggestions about mutual influences of eye dipoles as revealed by EOG.

Electro-oculographic response is recorded from a number of normal subjects: one eye becomes adapted to light, while the contralateral one persists in its dark-adapted state. The viewing eye shows the expected light-induced amplification effect. The contralateral eye shows the expected "paradoxical' curve in 12 cases; in addition, a flat curve is found in 4 cases, and a curve running parallel to that recorded from the light-exposed eye is found in 8 cases. In agreement with a previous report, found in the literature, cortical bio-electrical activity (on-going EEG) also shows a light-induced amplification after the onset of an adapting field. This latter finding is once more confirmed by us. This fact, in conjunction with some recent psychophysical findings (Lansford and Baker effect) leads to infer that interocular EOG influences are mediated by other mechanisms, in addition to spread across facial tissues.