Miosis Research Articles

Yenidoğanda Tizanidin Zehirlenmesi

Tizanidine an imidazole derivative is a novel centrally acting muscle relaxant Adult case of tizanidine over dosage is expressed as coma miosis nistagmus and respiratory depression with Cheyne Stokes respiration There is limited experience with the drug in children and there have been no reported cases of tizanidine toxicity in a neonate In this paper a 25 day old neonate with tizanidine intoxication is presented to point out the hazard of improper use of drugs in the neonatal period Key words: Neonate Intoxication Tizanidine

Affective Attitudes of Children and Adults in Relation to the Pupil Diameter of a Cat: Preliminary Data

ABSTRACTChildren from ages 9 to 11 years, as well as adults, express a preference for the picture of a cat with constricted pupils in relation to the same picture with dilated pupils. There was no difference for children from ages 4 to 6 years. The discussion concerns the mechanisms and determinants of these affective attitudes.

Skin ERGs: their effectiveness in paediatric visual assessment, confounding factors, and comparison with ERGs recorded using various types of corneal electrode

Comparison of scotopic and photopic ERGs recorded using a variety of ERG electrodes show that contact lens electrodes produce the largest ERGs, and these are about 30–50% larger compared with those recorded with foil or thread electrodes, which contact a smaller part of the cornea. Flash ERGs recorded from infra-orbital skin electrodes are about one eight the size of those recorded with contact lens electrodes, and around one quarter the size of those recorded with foil or fibre corneal electrodes. Reliable ERGs can be obtained in young children from infra-orbital electrodes sited centrally, within 1 cm of the rim of the eyelid, when signal averaging is used. Stimulation under fully darkened laboratory conditions with red and dim blue flashes permit assessment of cone and rod function, respectively. Factors such the recording electrode position, electrode derivation, upward rotation of the eye, eyelid closure and markedly constricted pupils can degrade the skin ERG. There are strong diagnostic advantages in recording the VEP concurrently with the skin ERG, particularly in young children. Examples of recordings in Leber's amaurosis, delayed visual maturation, albinism, optic nerve hypoplasia, achromatopsia add X-linked congenital stationary nightblindness are shown to demonstrate how ERG/VEP recordings can help in distinguishing between these conditions.

Changes in pupillary diameter in relation to eye-movement and no-eye-movement periods in the human fetus at term

OBJECTIVE: The aim of our study was to reveal whether pupils dilate and constrict in a time sequence in the human fetus and to assess the relationship between changes in pupillary diameter and eye-movement-no-eye-movement periods. STUDY DESIGN: We simultaneously observed pupil and eye movement with real-time ultrasonography in 30 human fetuses at 36 to 41 weeks' gestation. Eighteen were excluded because of data loss. Statistical analysis of pupillary diameter changes were made on the remaining 12 fetuses with the least median of squares regression. RESULTS: Pupillary diameters were found to be differentiated with statistical significance into two groups: 9.7% for the dilated pupil (median 3.0 mm) and 90.3% for the constricted pupil (1.7 mm). The percentage of dilated pupils during the eye-movement period (14.3%) was significantly greater than that during the no-eye-movement period (2.3%; Wilcoxon rank sum test, p<0.0001). CONCLUSION: These findings indicate a close relation between pupillary dilatation and eye-movement periods in the human term fetus.

Special Indications for Hydrogel IOLs. Small-incision Technique with Iridoplasty

We reviewed 38 patients following cataract surgery with posterior chamber lens (PCL) implantation and iridoplasty: in 18 eyes p-HEMA lenses (‘IOGEL’ PC 12) were inserted by small incision technique and in 20 eyes PMMA lenses with polypropylene haptics were implanted as controls. All operated eyes achieved the best possible visual acuity. The p-HEMA lenses were well tolerated in the postoperative period up to 12 months. Moderate fibrin exudate was observed in two eyes but no synechiae to the PCL developed. In the PMMA group, precipitates on the lens surface and posterior synechiae were seen in six eyes. Thus the p-HEMA lens appears to be a better alternative to the PMMA lens for eyes with a tendency to severe postoperative inflammatory reactions, including eyes that have been previously operated on, and glaucomatous eyes with constricted pupils.

Simulating age-related optical changes in the human eye.

The decline in visual function observed in older adults has been attributed to a deterioration in optical quality, decreased neural function, or a combination of both of these factors. One way of separating their contribution is to design a simulation of the optics of the elderly eye and examine its effect on the visual performance of younger observers. The age-related reduction in pupil size was simulated by the administration of an ophthalmic miotic drug, whilst a neutral density filter was included to account for the increased absorption of the ocular media. An optical cell containing a critical concentration of 500 nm diameter polystyrene microspheres in suspension was used to simulate light scatter. The spatiotemporal contrast sensitivity of an older group of observers was then compared with that of a younger group with and without the optical simulation. The contrast sensitivity of the younger group was consistently better than that of the older, and the presence of the optical simulation produced no significant effect on performance. This suggests that, under normal viewing conditions, it is primarily neural factors which underlie the deterioration in visual quality experienced by older observers.

Intraocular dapiprazole for the reversal of mydriasis after extracapsular cataract extraction with intraocular lens implantation: Part I: Dose-response correlation

Dapiprazole, an alpha-blocking miotic drug, was used intracamerally at the end of extracapsular cataract extraction with posterior chamber intraocular lens (IOL) implantation. The doubleblind study included 120 patients divided into four groups of 30 eyes; the groups received balanced salt solution, 0.125%, 0.25%, or 0.5% intraocular dapiprazole after IOL implantation and before suturing. Pupillary diameter recordings were performed immediately before and a few minutes after drug injection and two, four, and eight hours after surgery. The results showed a significant reversal of mydriasis by intraocular dapiprazole, especially with the 0.25% and 0.5% concentrations which did not differ significantly in effectiveness and safety.

Static and dynamic pupillometry for determination of the course of gradual detoxification of opiate-addicted patients

In order to assess the course of methadone (Heptadone) substitution therapy, 29 inpatients at the Vienna Psychiatric University Clinic (21 males, mean age = 27 years, SD 4 years; 8 females, mean age 29.75 years, SD 5.28 years) who were addicted to opium tea or to a mixture of opium and heroin were investigated by means of computer-assisted "static"- and "light-evoked dynamic" pupillometry. Pupillary measurements were carried out before the start of withdrawal, on the 2nd day 48 h after the administration of 10 mg methadone, and again after the maximum and half of the maximum dose of methadone had been administered. The constricted pupils (the effect of opiate) showed dilatation after the withdrawal syndrome appeared, but immediately after the start of the detoxification treatment, as well as 1 day after administration of the maximum methadone dose a decrease of pupillary diameter was observed. The narrowing of the pupil was followed by an increase in pupillary diameter, which peaked 48 h after the last minimal dose of methadone and nearly reached the normal level. The widening of the pupil reflects an increase of noradrenergic activity under conditions of opiate withdrawal. An increase of spontaneous fluctuations was observed during withdrawal and was only inhibited by the maximum dose of methadone. Finally, pupillary dynamics (shortening of latency time and increase of relative changes) improved during therapy. The pupillary measurement corresponded with clinical observations as well as with self-evaluation during treatment. Thus pupillometry seems to be a useful instrument for assessment of treatment of opiate-addicted patients.

Dose-dependent miosis by substance P eyedrops in humans

Dose-dependent miosis by substance P eyedrops in humans

Zolpidem Intoxication Mimicking Narcotic Overdose: Response to Flumazenil

Zolpidem is a recently introduced sleep-inducer which is thought to act on the central-type benzodiazepine receptors. This observation is the first report of drug poisoning with this compound. The toxic response was characterized by the development of a profound but short-lasting coma, associated with pin-point pupils and respiratory depression, as observed in a narcotic overdose. These clinical signs were not influenced by the administration of naloxone, but responded dramatically to flumazenil. Some analytical data on zolpidem toxicokinetics are presented.

Consensual pupillary responses to mydriatic and miotic drugs.

1. Three experiments were conducted to examine whether mydriatic or miotic drugs instilled into one eye have any effect on the diameter of the pupil of the untreated fellow eye, in healthy volunteers. 2. In Experiment 1, the effects of four subjects, using photography in an illuminated room to assess pupil diameter. The drug evoked a dose-dependent mydriasis in the index eye which was accompanied by a simultaneous dose-dependent miosis in the fellow eye. 3. In Experiment 2, the same method was used to assess pupil diameter as in Experiment 1. The effects of mydriatic (methoxamine and tyramine) and of miotic (pilocarpine) drugs instilled into the fellow eye, were studied on the sizes of pupillary responses to the same drugs instilled into the index eye. The presence of a mydriatic drug in the fellow eye resulted in a decrease in the size of the mydriatic responses in the index eye. 4. In Experiment 3, the effects of three concentrations of phenylephrine hydrochloride (0.15-0.60 M) and of three concentrations of pilocarpine hydrochloride (0.002-0.008 M), were studied in darkness using an infra-red binocular television pupillometer, in seven subjects. Phenylephrine evoked dose-dependent mydriasis and pilocarpine evoked dose-dependent miosis. The pupillary responses of the index eye were not accompanied by any changes in the diameter of the pupil of the fellow eye. 5. It is concluded that drug-induced mydriasis in the index eye is accompanied by a consensual miosis in the fellow eye.(ABSTRACT TRUNCATED AT 250 WORDS)

Lateral pontine hemorrhage: Atypical clinical manifestations and good outcome

Two hypertensive patients presented clinically with unilateral hematomas of the basis pontis demonstrated by computed tomography (CT) scan. Clinical signs showed hemiparesis while the typical signs of pontine hemorrhage—including coma, pin point pupils, ocular bobbing, respiratory abnormalities, and hyperthermia—were absent. Both patients survived with good recovery. Our observations suggest that some patients with pontine hemorrhage produce atypical clinical manifestations and have a good prognosis. Accurate diagnosis may be difficult without CT scan in such cases.

Neurologic manifestations of heatstroke at the Mecca pilgrimage.

We analyzed the extent, pattern, and evolution of neurologic dysfunction in 87 patients with heatstroke at the Mecca pilgrimage. Disturbance of consciousness and constricted pupils were seen in all patients. Deep coma, areflexia, and absent brainstem reflexes were seen in 25 patients (29%). Automatic complex movements (chewing, swallowing, and lip smacking) were seen in 17 patients (30%). Body shivering during cooling occurred in six patients (7%). Recovery was uncomplicated in 75 patients (87%). Two (2%) recovered but developed pancerebellar syndrome. Ten patients (11%) died.

Drug points: Pinpoint pupils in mianserin overdose

Drug points: Pinpoint pupils in mianserin overdose

Color-Coded Caps for Drugs

To the Editor. —The use of colored caps—red for mydriatic drugs and green for miotic drugs—has been an industry standard and has simplified patient direction and understanding. It would be helpful if each category of medication, eg, β-blockers, steroids, antibiotics, and tear replacements, were assigned a specific colored cap.

Affective responses as guides to category-based inferences

Initial nonconscious affective reactions to a target individual may influence a perceiver's selection from among descriptively plausible categories with which to organize his impression of the target. Specifically, a perceiver may be more likely to employ a category that is consistent, in affective tone, with the tone of his affective reaction. Subjects in two studies were exposed to photographs of faces of target individuals. Degree of preference for the faces was manipulated, outside of subjects' awareness, by varying the state of pupillary dilation. Participants in Study One reported that verbal descriptions that characterized positively (compared to negatively) evaluated category prototypes were more likely to be descriptive of targets with dilated pupils. Similarly, participants judged descriptions that characterized negatively (compared to positively) evaluated prototypes as more likely to be descriptive of targets with constricted pupils. In Study Two, subjects' recall of personality descriptions that were (evaluatively) inconsistent with their initial affective response to the target was superior to their recall of descriptions that were (evaluatively) consistent with the tone of their initial response. The data are interpreted as evidence for the importance of nonconscious affective reactions in guiding the process of impression formation.

On the gekko pupil and scheiner's disc

The four pinhole apertures of the constricted gekko pupil are an adaptation for decreasing the depth of field of the eye, while decreasing the total light flux to the retina. This may be useful for distance estimation at high light levels.

Traumatic Huge Acute Subdural Hematoma of the Posterior Fossa in a Child

Acute subdural hematoma of the posterior fossa is rare, occupying 0.5% to 1.6% of all acute subdural hematomas. In children, it is extremely rare. There has been only 11 cases reported in the literature, excluding neonatal cases. Herein a case was reported of an acute subdural hematoma of the posterior fossa in a child who survived after an emergent surgical exploration. A 6-year-old female was involved in a motor vehicle accident. She fell to the ground, hitting the left occipital region. After a semi-lucid interval several hours, her consciousness deteriorated and she was brought to the hospital. On examination, the patient was comatose, and showed decerebrate posture with bilateral pin-point pupils. Computed tomography scan revealed a huge hematoma which occupied the left posterior fossa and moderate obstructive hydrocephalus. A left suboccipital emergency craniectomy was performed, and an occipital bone fracture was confirmed. Then, subdural hematoma was confirmed, which seemed to be caused by bleeding from a cerebellar cortical small artery. Most of the clots were removed, and hemostasis was achieved. The postoperative course was favourable. The patient became alert 2 weeks later, and was discharged with a very mild ataxic gait 2 months later. No post-traumatic hydrocephalus is seen as yet.

Leprosy in a trachomatous population.

In an Egyptian leprosy hospital, 17% of 133 patients had a visual acuity of less than 3/60. Corneal opacity, phthisis bulbi, and cataract accounted for 85% of blindness. Leprosy and trachoma together produce blinding corneal opacity by exposure, leprous keratitis, and trichiasis and entropion. Inturned lids, a late result of conjunctival scarring due to childhood trachoma, were less frequent in patients with lepromatous leprosy than in patients with tuberculoid leprosy; because conjunctival scarring from trachoma depends on cell-mediated immunity, patients with lepromatous leprosy may not have had severe trachomatous scarring develop due to their lifelong abnormality in cellular immunity. In patients with leprosy, even when complicated by trachoma, simple measures to prevent or restore vision include medical treatment of leprosy, surgical correction of lid deformities, sector iridectomy for constricted pupils or central corneal opacities, and cataract extraction.

Effects of the combination of tripelennamine and Pentazocine at the behavioral and molecular levels

The purpose of the present experiments was to determine if the antihistamine tripelennamine potentiates the morphine-like effects of the narcotic-antagonist analgesic pentazocine at the behavioral level or the molecular level or both. At the behavioral level, the effects of pentazocine were determined alone and in combination with tripelennamine in rats trained to discriminate between saline and either morphine or the psychotomimetic narcotic derivative SKF 10,047. The interaction between pentazocine and tripelennamine were also evaluated in the guinea-pig ileum preparation and in the [ 3H]-naloxone opiate receptor binding assay. Tripelennamine significantly enhanced the morphine-like discriminative stimulus effects of pentazocine and markedly reduced the SKF 10,047-like stimulus effects of pentazocine. Naloxone antagonized the morphine-like effects of pentazocine plus tripelennamine. Pentazocine significantly constricted pupils in the rat, an effect which was addictive with the mydriatic effects of tripelennamine. Inhibition of the twitch-height of the electrically stimulated guinea-pig ileum by pentazocine was not affected by tripelennamine. Further, tripelennamine did not modify the K e for naloxone in antagonizing pentazocine. Inhibition of specific [ 3H]-naloxone binding by pentazocine was also not affected by tripelennamine. These results are consistent with the hypothesis that the potentiation of the morphine-like effects of pentazocine by tripelennamine which was observed behaviorally was not due to molecular interactions at the morphine receptor. At least a part of this interaction may be attributable to tripelennamine decreasing the psychotomimetic actions of pentazocine.