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Ross' syndrome (tonic pupil plus).

Two cases of tonic pupil, hyporeflexia, and segmental hypohidrosis (Ross' syndrome) are reported. The relationship of this syndrome to other autonomic dysfunction is discussed. Those symptoms (emotional instability, loss of sweating, orthostatic hypotensive symptoms, and signs of bilaterality of the tonic pupil) which should alert the clinician to more extensive disease states are noted. It is suggested that these conditions may represent a continuum or spectrum of disorders with a widespread degree of severity and progression.

Adie Syndrome↗

Waardenburg syndrome with a fixed dilated pupil.

An unusual case of Waardenburg syndrome associated with a detailed and fixed pupil of the lighter eye is described. Pharmacological investigations were performed to localise the site of the pupillary lesion. A lack of cholinergic reactivity was demonstrated, possibly due to congenital agenesis of the sphincter pupillae. Sympathetic activity was not impaired. Spiral ganglion agenesis and midline congenital anomalies are common features in Waardenburg syndrome. These lesions as well as the fixed dilated pupil might be due to an embryonal inductive failure.

Abnormalities, Multiple↗

Influence of pupil size on measurements made with the Lens Opacity Meter 701.

The Lens Opacity Meter 701 (Interzeag, Switzerland) is a recently developed instrument for assessing cataract. It measures the degree of scatter of a red light beam by the lens. Fifty patients prior to cataract surgery had measurements made before and after dilatation of the pupil. Inconsistent results were found at pupil diameters of less than 4 mm. It is postulated that this was due to absorption of scattered light by the iris.

Cataract↗

The fixed dilated pupil after cataract surgery--is it related to intraocular use of hypromellose?

Hypromellose can be used as a viscoelastic substance during cataract surgery. Two groups of patients, one group operated on using hypromellose, the other using sodium hyaluronate as a viscoelastic substance were followed up 2-6 months postoperatively. A total of 16.7% of the eyes operated on using hypromellose developed a non-reactive semidilated pupil whereas none of the eyes from the control group developed this phenomenon. It was concluded that there is a probable link between the intraocular use of hypromellose and abnormal pupils after cataract surgery.

Aged↗

Pupil cycle time: a simple way of measuring an autonomic reflex.

Persistent regular oscillations of the pupil of the eye can be induced using a slit-lamp. The period of these oscillations, pupil cycle time (PCT), is simple to measure with a hand-held stop-watch. Evidence from pharmacological testing suggests that PCT is a sensitive measure of dysfunction of the parasympathetic efferent limb of the pupillary light reflex arc. This is confirmed by the finding that PCT is prolonged in a high proportion of patients with evidence of autonomic neuropathy judged by abnormalities of their cardiovascular reflexes. The method provides a simple, non-invasive way of quantifying an autonomic reflex and it may be of value in investigating patients with diseases affecting the autonomic nervous system.

Adult↗

Initial enlargement of the opposite pupil as a false localising sign in intraparenchymal frontal haemorrhage.

Ipsilateral third nerve palsy with early pupillary enlargement is an important sign of transtentorial herniation from a supratentorial mass lesion. A case of frontal, intraparenchymal haemorrhage is reported in which the first ocular manifestation of transtentorial herniation was enlargement of the contralateral pupil. The ipsilateral pupil dilated only after complete oculomotor palsy of the contralateral eye. After partial frontal lobectomy and removal of blood clot, the ipsilateral third nerve recovered before the contralateral third nerve. Clinical findings localised the contralateral third nerve lesion to an extra-axial site. The possible mechanisms of contralateral third nerve compression are discussed. This seems to be the first example of pupillary enlargement as a false localising sign from a contralateral, supratentorial, intraparenchymal mass lesion.

Adult↗

Fixed and dilated pupils after trauma, stroke, and previous intracranial surgery: management and outcome.

OBJECTIVES: To clarify whether different causative events (trauma, stroke, intracranial surgery), time of intervention, and treatment mode influence outcome, patients with fixed and dilated pupils (FDPs) in a prospective neurosurgical series were evaluated. METHODS: Ninety nine consecutive patients who presented with or developed one or two FDPs, were split into three groups according to the respective aetiology: 46 patients had a trauma, 41 patients a stroke (subarachnoid or intracerebral haemorrhage), and 12 patients had undergone previous elective intracranial surgery. Appropriate therapy was performed depending on the CT findings. Outcome was classified according to the Glasgow outcome scale (GOS). RESULTS: Overall mortality was 75%. In 15% outcome was unfavourable (GOS 2 and 3), and in 10% favourable (GOS 4, 5) at 24 month follow up. No differences in outcome were found between trauma, stroke, and postelective surgery groups. Unilaterally FDP was associated with a better chance of survival (46% v 13%; p<0.01). Age did not correlate with survival, but younger survivors had a significantly better outcome. Patients in whom an intracranial mass was removed surgically had a 42% survival rate, compared with 8% with conservative treatment (p<0.01). Patients with a shorter delay from FDPs to intervention had a better chance of recovery after trauma and previous intracranial surgery (p<0.05). No patient survived better than a vegetative state, if previous FDPs did not become reactive shortly after therapy. If both pupils became reactive on therapy, the chance of survival was 62%. Of these survivors 42% had a favourable outcome. CONCLUSION: Bilateral restoration of pupillary reactivity shortly after therapy is crucial for survival. Surgical evacuation of an intracranial mass, unilateral FDPs, early intervention, and younger age are related to better chances of survival or recovery. The prognosis of patients with FDPs after trauma, stroke, and previous elective intracranial surgery is similar.

Adolescent↗

Bupranolol, a beta 1- and beta 2-blocker, causes constriction of the pupil in men.

Two out of three normal eyes tested with frequent instillation of 30 microliters of drops of 0.5% bupranolol, a beta 1 + beta 2 blocking drug with some intrinsic sympathomimetic and local anesthetic activity, showed a miotic effect of the order of a 25% reduction of pupil area, as estimated by an open-loop iris-videorecorder. A slight contralateral effect was also observed. Blocking by the drug of tonic inhibitory beta-adrenergic activity on the sphincter muscle of the pupil is postulated.

Adrenergic Fibers↗

The effects of phenylephrine on pupil diameter and accommodation in rhesus monkeys.

PURPOSE: Phenylephrine is used to dilate the iris through alpha-adrenergic stimulation of the iris dilator muscle. Sympathetic stimulation of the ciliary muscle is believed to be inhibitory, decreasing accommodative amplitude. Investigations in humans have suggested some loss of functional accommodation after phenylephrine. It is unclear whether this loss is due to direct action of phenylephrine on the ciliary muscle or to secondary optical factors associated with mydriasis. The purpose of this study was to determine whether phenylephrine affects Edinger-Westphal (EW)-stimulated accommodation in rhesus monkeys. METHODS: The time course for maximum mydriasis was determined by videographic pupillography after phenylephrine instillation in 10 normal rhesus monkeys. Static and dynamic EW-stimulated accommodative responses were studied in five iridectomized rhesus monkeys before and after phenylephrine instillation. Accommodative amplitude was measured with a Hartinger coincidence refractometer. Dynamic accommodative responses were measured with infrared photorefraction, and functions were fitted to the data to determine peak velocity versus accommodative response relationships. RESULTS: The maximum dilated pupil diameter of 8.39 +/- 0.23 mm occurred 15 minutes after administration of phenylephrine. In iridectomized monkeys, postphenylephrine accommodative amplitudes were similar to prephenylephrine amplitudes. Dynamic analysis of the accommodative responses showed linear peak velocity versus accommodative amplitude relationships that were not statistically different before and after phenylephrine. CONCLUSIONS: alpha-Adrenergic stimulation causes a strong pupil dilation in noniridectomized monkey eyes but does not affect EW-stimulated accommodative amplitude or dynamics in anesthetized, iridectomized rhesus monkeys.

Accommodation, Ocular↗

Effects of pirenzepine on pupil size and accommodation in rhesus monkeys.

PURPOSE: Pirenzepine is suggested to be a relatively selective muscarinic (M(1)) antagonist and is currently under investigation for the treatment of myopia. Atropine, a nonselective M-type antagonist, is used in the treatment of myopia, but has undesired ocular and systemic side effects. An M(1)-specific antagonist may decrease side effects and remain effective at reducing the progression of myopia. In the current study, the effects of pirenzepine on pupil diameter, resting refraction, and accommodation were studied in rhesus monkeys. METHODS: The time course and extent of mydriasis from subconjunctival injection of 2% pirenzepine were determined in five normal rhesus monkeys, and the effects on static and dynamic accommodation were determined in four rhesus monkeys with permanent indwelling electrodes in the Edinger-Westphal (EW) nucleus of the midbrain. Subconjunctival injections of 0.0002% to 0.2% pirenzepine in log unit dilutions were tested in three monkeys to determine the effects on static EW-stimulated accommodation. At 40 to 50 minutes after pirenzepine injection, accommodation was stimulated pharmacologically in both eyes, and the response was measured for 30 minutes. RESULTS: After 2% pirenzepine injection, pupil size increased 2.02 +/- 0.41 mm, there was a hyperopic shift in resting refraction of 1.07 +/- 0.23 D, and nearly complete cycloplegia occurred. Maximum EW-stimulated accommodation was significantly decreased 20 to 40 minutes after 0.02% or greater pirenzepine. Carbachol-stimulated accommodation was significantly decreased after 0.2% or greater pirenzepine. CONCLUSIONS: Subconjunctival injections of 0.02% or greater pirenzepine result in a significant decrease in accommodation and are probably acting through nonselective muscarinic antagonism. Subconjunctival injections of 0.002% or less pirenzepine do not decrease EW-stimulated accommodation.

Accommodation, Ocular↗

Hereditary sensory neuropathy and tonic pupils.

The clinical features of two siblings with both hereditary sensory neuropathy and bilateral tonic pupils are described. Other neurologic disorders associated with tonic pupils are reviewed. Our patients appear to represent a unique instance of the association of disorders that primarily affect the ciliary and dorsal root ganglia.

Adult↗

Using color substitution pupil response to expose chromatic mechanisms.

It is well known that pupillary threshold shows a scotopic spectral behavior, even for foveal stimuli. However, when two scotopically balanced fields at different wavelengths are alternated, the pupil shows a constriction response at each transition, exposing innervation from chromatic mechanisms. Using a suitable model for pupillary innervation, this substitution response is systematically studied for different wavelengths and radiant power levels to yield (within the accuracy of the assumptions of the model) spectral threshold curves for the chromatic mechanism as indicated by the pupil. Four mechanisms have thus been identified, having peak sensitivities near 450, 525, 580, and 495 nm. We propose that these represent the blue, green, red and scotopic mechanisms as maintained before the level of the lateral geniculate body.

Color Perception↗

Measuring eye aberrations with Hartmann-Shack wave-front sensors: should the irradiance distribution across the eye pupil be taken into account?

A usual approximation in Hartmann-Shack aberrometry is that the centroid displacements are proportional to the spatial averages of the wave-front slopes at the sampling subapertures. However, these spatial averages are actually weighted by the local irradiance distribution across each microlens. The irradiance across the eye pupil is not uniform in usual reflectometric aberrometers, which is due to several factors including retinal scattering and cone waveguiding directionality. It is shown that neglecting this fact in usual least-squares reconstruction procedures gives rise to a biased estimation of the aberration coefficients. The magnitude of this bias depends on the actual irradiance distribution across the eye pupil, the mode being estimated, the detailed modal composition of the aberrated wave front, and the geometry of the wave-front sampling array. Order-of-magnitude calculations suggest that this bias may well be in the range 5%-10% for relatively smooth irradiance distributions. The systematic nature of this error makes it advisable to check for its presence and, if required, to compensate for it by an adequate choice of the least-squares reconstruction matrix.

Humans↗

Direct transformation of Zernike eye aberration coefficients between scaled, rotated, and/or displaced pupils.

In eye aberrometry it is often necessary to transform the aberration coefficients in order to express them in a scaled, rotated, and/or displaced pupil. This is usually done by applying to the original coefficients vector a set of matrices accounting for each elementary transformation. We describe an equivalent algebraic approach that allows us to perform this conversion in a single step and in a straightforward way. This approach can be applied to any particular definition, normalization, and ordering of the Zernike polynomials, and can handle a wide range of pupil transformations, including, but not restricted to, anisotropic scalings. It may also be used to transform the aberration coefficients between different polynomial basis sets.

Computer Simulation↗

Translational and rotational pupil tracking by use of wavefront aberration data and image registration techniques.

We present a methodology with which to evaluate translations and rotations of wavefront aberration measurements of systems in which the exit pupil suffers displacements and rotations with respect to the reference frame of the measuring device. We propose to use image registration techniques to account for rotations, translations, and scale changes of the pupil. We present a proof of principle, using an artificial eye in addition to computer simulations. The method is software based and requires no additional hardware.

Algorithms↗

[Teaching and learning in the physical exam: an analysis of the process by an exam of the pupils].

The goal of this study was to analyse the teaching-learning process of the pupil examination, in two aspects: the pupil diameter (DP), obtained by measurement and photomotor reflex (RFM), by subjective judgement. The sample was composed by 46 students of 4th semester in Nursing Undergraduate Course of University of São Paulo. The study was developed in two phases: the first was at nursing laboratory and the second, at clinical practice. The findings seemed to indicate that the learning was done because there was high level of agreement among students in their observation, development of an ability and a specific knowledge. The major difficulties was at clinical practice.

Adult↗

An ocellar "pupil" that does not change with light intensity, but with the insect age in Triatoma infestans.

The simple eyes (ocelli) of recently emerged adult Triatoma infestans exhibit a narrow elongated "pupil", surrounded by a ring of brown-reddish pigment, the "iris". This pupil does not respond to changes in the illumination, but varies in size after the imaginal ecdysis. This change corresponds, internally, with the growth of the corneal lens and the associated retina up to an age of about 20 days. This has not been previously observed in an insect. The use of this characteristic for recognising young adults of this species is suggested.

Aging↗

The pupil in congenital third nerve misdirection syndrome.

The involved pupil in the syndrome of aberrant regeneration of the oculomotor nerve usually remains larger than the uninvolved side, or approaches equality in size. A 4-year-old child was seen with congenital aberrant regeneration of the right third nerve. The right pupil was consistently smaller than the left, but particularly so in dim illumination. The question can be raised as to whether relative pupillary miosis more commonly follows third nerve misdirection in children than adults.

Child, Preschool↗