Biomedical subjects

W D Lagreze

Publications and source records attributed to W D Lagreze.

4 recordsLinked to original sources

PubMed1996

Mesencephalic clefts with associated eye movement disorders.

OBJECTIVE: To describe two patients with mesencephalic midline clefts and associated eye movement disorders. DESIGN: Case reports. RESULTS: The first patient developed bilateral internuclear ophthalmoplegia with exotropia, reduced convergence, right ptosis, right fourth-nerve palsy, and right elevator palsy several years after meningitis with hydrocephalus. The second patient had bilateral internuclear ophthalmoplegia with exotropia, reduced convergence, bilateral ptosis, limited upward gaze, and right hypertropia since childhood. In both patients, magnetic resonance imaging showed a midline cleft extending from the cerebral aqueduct into the midbrain. CONCLUSION: It is likely that the clefts affected the oculomotor nuclei and medial longitudinal fasciculi, accounting for the eye movement disorders.

Adult↗

PubMed1996

Effect of surgical technique on the increase in intraocular pressure after cataract extraction.

BACKGROUND AND OBJECTIVE: A prospective study was performed to determine the influence of surgical technique on the increase in intraocular pressure (IOP) after cataract surgery. PATIENTS AND METHODS: Three groups of 30 patients each underwent either extracapsular cataract extraction with sclerocorneal suture (ECCE), phacoemulsification with sclerocorneal suture (PS), or phacoemulsification with a sutureless scleral tunnel (PT). RESULTS: Each group experienced a significant increase in IOP 5 to 7 hours after surgery: 20.2 +/- 7.9 mm Hg for ECCE, 11.2 +/- 8.3 mm Hg for PS, and 4.7 +/- 8.7 mm Hg for PT. The differences in the increases among the three groups were significant. CONCLUSION: PT [corrected] produces the lowest postoperative increase in IOP and should be considered for patients with glaucomatous damage.

Aged↗

PubMed1994

Asymmetries in preattentive line detection.

We tested the relative contribution of absolute orientation and collinearity to asymmetries in preattentive line detection. Subjects reported the location of a single line that was tilted by 16 deg against the orientation of the background lines. Perceptual pop-out strength was quantified as the threshold presentation time to correctly locate the salient element. We found that (1) threshold times were significantly shorter in vertical than in oblique background lines and that (2) threshold times were significantly shorter in collinear than in non-collinear background lines. Our data suggest that the sensitivity of preattentive processes for orientation gradients is modulated by both collinearity and absolute orientation.

Humans↗

PubMedDate not supplied

Distortions in two-dimensional visual space perception in strabismic observers.

Amblyopic subjects were asked to memorize circles of different radii (2, 4 and 6 degrees), and then to reconstruct them monocularly with each eye, point by point (12 points per circle). The resulting two-dimensional maps of visual space showed considerable distortions, including expansion, shrinkage and torsion of specific regions of the visual field of the amblyopic eye, but not the normal eye. Based on the differences between the two eyes, we computed complex two-dimensional patterns (gratings, checkerboards, optotypes, written text, natural scenes) as "seen" monocularly with the amblyopic eye. These reconstructed patterns were then compared with drawings of the same patterns observed through the amblyopic eyes of the same subjects. The reconstructed patterns only partially reflected the actual perception for the amblyopic eyes. The compensation of complex, globally-extended scenes in comparison to the distortions obtained by local, punctate settings probably reflects cooperative interactions occurring at higher brain levels.

Adult↗