(1) Thirteen patients had had a posterior dislocation with an associated fracture of the femoral head located either caudad or cephalad to the fovea centralis (Pipkin Type-I or Type-II injury), one had had a posterior dislocation with associated fractures of the femoral head and neck (Pipkin Type III), two had had a posterior dislocation with associated fractures of the femoral head and the acetabular rim (Pipkin Type IV), and three had had a fracture-dislocation that we could not categorize according to the Pipkin classification.
(2) Foveal involvement included coarse foveal granularity, thinning of the foveal retinal pigment epithelium, increasing encirclement of the fovea with focal areas of atrophy, and minimal macular drusen.
(3) Detection thresholds at 10 Hz and high grating contrasts were approximately 11-15 arcsec in the fovea and 37-47 arcsec at 30 degrees eccentricity.
(4) These data reject the possibility that albino central vision is similar to normal peripheral vision, but the results are predictable on the hypothesis that the central retina of albinos is a spatially magnified (underdeveloped) version of the normal fovea.
(5) Macular pigment density was determined by comparing sensitivity under these conditions for the fovea, where macular pigment is maximal, and 5 degrees temporally.
(6) We confirmed this observation (Experiment I) and have mapped out a 2 dimensional "perceptive field" for crowding in the fovea using a 2 dot target (Experiment II).
(7) At earlier fetal ages, the site of the future fovea was identified by several criteria that included peak density of ganglion cells, lack of blood vessels in the inner retinal layers, arcuate fiber bundles, and the absence of rod outer segments in the photoreceptor layer.
(8) By reconstructing the fovea from serial sections, we were able to compare the densities of cones, cone pedicles and ganglion cells; in this way we found that there are more than three ganglion cells per foveal cone.
(9) There are two separate regions of high magnification factor, the projection areas of the fovea and the middle of the red area in the retina, each of which has a correspondingly high density of neurones in the ganglion cell layer.
(10) From 1967 to 1987, 16 patients underwent repair of chronic cerebrospinal fluid rhinorrhea in the cribriform plate or fovea ethmoidalis at the University of Iowa with an osteomucoperiosteal flap.
(11) The fovea is represented at the lateralmost portion of MT, while the retinal periphery is represented medially.
(12) The greatest thickness of cartilage was always found lateral of the fovea capitis at the medial margin of the pressure area ("Druckbündelzone") of the cancellous bone, whereas the dorsomedial part of the head showed a zone of thinning, extending to the medial margin of the fovea capitis.
(13) The nature and size of a localized scotoma such as the type caused by a macular lesion was estimated by measuring spatial contrast sensitivity as a function of retinal area centered on the fovea.
(14) In divergent squint, the fovea competes with the much weaker nasal hemifield.
(15) The nonfreezable water content (bound water) showed a decreasing gradient along the optic axis from lens to fovea; an opposite trend than that found in bovine vitreus.
(16) ERGs recorded by this technique can be considered focal since (i) they show a sharp fall-off in amplitude when the stimulus is displaced from the fovea, and (ii) they are no longer recordable when the stimulus is centered on the optic disk or on a large macular scar.
(17) This was compared with MF at the dorsal lateral geniculate nucleus and at striate cortex, revealing that the relative representation of the fovea increases substantially in both thalamus and cortex.
(18) The authors present and discuss the results obtained and suggest that photocoagulation of subretinal new vessels not involving the fovea can be worth performing.
(19) Their receptive fields were usually large, not restricted to the contralateral visual field and always included the fovea.
(20) We feel that tenuous attachments of the vitreous body to the fovea could exert traction on the vitreo-retinal interface or shrinkage of a fibrocellular membrane on the inner foveal surface could lead to the observations made by us.
Foveate
Definition:
(a.) Having pits or depressions; pitted.
Example Sentences:
(1) Results of tests on 4 mammalian, 19 reptilian, and 17 avian species confirmed the prediction that lack of optomotor response to monocular optokinetic stimulation in one of the two horizontal directions would correlate with afoveate retinal organization, whereas consistent optomotor responses to monocular stimulation in either horizontal direction would correlate with foveate organization.
(2) On the other hand, a recent hypothetical model of the defective oculomotor system producing congenital nystagmus emphasizes that the time constant of the (increasing velocity) slow-phase eye movements should represent a useful parameter in the quantification of the surgical effects, since it is related to the potential good visual acuity of the patients in the presence of nystagmic cycles with extended foveation.
(3) Recent neurophysiological studies have disclosed that the nucleus of the optic tract (NOT) in the pretectum is the first relay station responsible for horizontal optokinetic nystagmus (OKN) both in non-foveate and foveate animals.
(4) This behavioral difference suggests that a distinctive mechanism exists for foveating targets.
(5) These characteristics indicated that the visually evoked saccades subserving foveation had increased gain, and were modelled by computer simulations using a sampled-data control model with increased feed-forward gain.
(6) If PRL acquire the foveal characteristic of a retino-motor center then visually guided saccades would acquire the properties of foveating saccades.
(7) Saccadic amplitude was reduced, causing the monkeys' initial attempt to fall short of foveating the target.
(8) Saslow and others have shown that the latency of foveating saccades can be altered by changing the offset time of the current fixation point relative to the onset of the peripheral target.
(9) The waveform and precision of foveation were not found to be related to any one classification group (eg.
(10) We also found that with an illuminated background the total time required to foveate the target was shorter than when the background was dark.
(11) As a result, the visual cortical model carries out foveation responses to input stimuli that require the dynamic conjunction and discrimination of form, color, and location for successful performance.
(12) We developed several methods to accurately measure the dynamics of foveation in CN; their use is illustrated on an individual with typical idiopathic CN and no afferent defects.
(13) Foveating saccades have a shorter initiation latency and are faster than non-foveating saccades.
(14) The relations depend on whether the stimulus is the target for a foveating saccade, or is the cue for an "anti" saccade which peripheralizes the retinal image of the cue: (1) at scotopic luminances the differences between foveating and anti saccades are diminished, largely because foveation is the more severely affected.
(15) Latencies for pure rod and pure cone inputs obey Piéron's law in much the same manner as foveating saccades, except that latencies are somewhat longer.
(16) While foveation deletes their neural trace, it activates a class of cells that appear involved in the preparation of arm movements towards the foveated region.
(17) With the head in motion, vestibuloocular reflex (VOR) data showed eye velocities during these foveation periods that approximation head velocity.
(18) In the first task ('Instructed'), maintenance of gaze fixation was based on verbal instruction, whereas, in the second task ('Non-instructed'), it was based upon a foveating mechanism maintained by sensory stimulation during the performance of a categorization task.
(19) This cortical area contains the neural substrate of an encoding strategy for remembered or current events and objects in the behavioural surround that are not, as yet, foveated.
(20) Non-foveating saccades include other FEMs such as nystagmus quick phase, saccades without visual stimuli and visually-directed saccades that direct target images to eccentric retina.