Disease relevance of Mydriacyl

• Here it is reported that patients diagnosed with probable Alzheimer's disease by standard clinical criteria exhibited a marked hypersensitivity in their pupil dilation response to a cholinergic antagonist, tropicamide, placed in their eyes [1].
• Can tropicamide eye drop response differentiate patients with progressive supranuclear palsy and Alzheimer's disease from healthy control subjects [2]?
• We examined 14 patients with progressive supranuclear palsy (PSP), another related neurodegenerative disorder characterized by severe widespread cholinergic deficits and known central hypersensitivity to cholinergic blockade, to determine whether they also showed a marked pupil dilation after administration of dilute tropicamide eye drops [2].
• PURPOSE: To analyze whether preinstillation of lignocaine potentiates mydriasis by tropicamide in dark eyes and to determine possible mechanisms for this effect [3].
• To evaluate the cycloplegic effect of 1% tropicamide in myopic children and to determine whether its efficacy is associated with age, gender, iris color, ethnicity, magnitude of the refractive error, or latent error [4].

Psychiatry related information on Mydriacyl

• Increased mydriatic response to tropicamide is a sign of cholinergic hypersensitivity but not specific to late-onset sporadic type of Alzheimer's dementia [5].
• The anticholinergic agent tropicamide causes a significantly greater change in the pupil diameter of patients with Alzheimer's disease (AD) than in that of patients with alcoholic or vascular dementia or in normal controls [6].
• The mydriatic response to eyedrops of the anticholinergic drug tropicamide at very low concentration (0.01%) was studied in subjects with Alzheimer's disease (AD, n = 10) and multi-infarct dementia (MID, n = 10) [7].
• The area under the mydriatic response-time curve (AUC 0-6 hr) was interpreted as an indication of the bioavailability of tropicamide in each vehicle [8].
• 3. Individual differences in pupil size due to anatomic variability or adrenergic tone were evaluated under conditions of maximum pupil dilation following cholinergic blockade (tropicamide, 0.5 percent) [9].

High impact information on Mydriacyl

• Apolipoprotein E epsilon 4 allele and pupillary response to tropicamide [10].
• The primary outcome measure was progression of myopia by autorefraction after cycloplegia with 2 drops of 1% tropicamide [11].
• Ibopamine, during its peak mydriasis, was associated with a very large increase in the rate of clearance of topically applied fluorescein from the cornea and anterior chamber, an effect that was not associated with tropicamide during its peak mydriasis [12].
• Compared with placebo and with the tropicamide control, ibopamine decreased intraocular pressure, despite its stimulation of aqueous humor flow [12].
• Comparative study of the effects of 2% ibopamine, 10% phenylephrine, and 1% tropicamide on the anterior segment [13].

Chemical compound and disease context of Mydriacyl

• Comparison of refractive error at each drug's reported time of maximum cycloplegia (30 minutes for tropicamide and 60 minutes for cyclopentolate) showed that distance autorefraction in the vertical meridian differed by +0.20 +/- 0.30 diopters (D) (P = 0.008) [14].
• Heart rate and blood pressure changes following 0.5% tropicamide and 2.5% phenylephrine hydrochloride were evaluated in seven ill preterm infants (birth weight, 910 to 2,060 gm; gestational age, 26 to 36 weeks) during the first day of life [15].
• OBJECTIVE: To examine the hypothesis that clonidine may potentiate tropicamide-evoked mydriasis [16].
• Ointment preparations of cyclopentolate hydrochloride and tropicamide were compared with aqueous drops of these medications for the production of mydriasis and/or cycloplegia in clinic patients [17].
• A retrospective study of 60 patients (116 eyes) with primary open angle glaucoma was done to assess the frequency and severity of intraocular pressure elevation following dilation with 2.5% phenylephrine hydrochloride (Neo-Synephrine) and 1% tropicamide (Mydriacyl) [18].

Biological context of Mydriacyl

• The effect of tropicamide on visual acuity was slight [19].
• Mucoadhesive polymer-coated vesicles failed to increase significantly the bioavailability of the entrapped tropicamide compared to uncoated vesicles and aqueous solution [20].
• Despite a limited sample size in the present study, our results indicate that the pupil dilation assay by tropicamide is not an effective diagnostic tool for AD, and it may be modulated by different gene dosage of ApoE epsilon 4 [21].
• Chromatic contrast sensitivity was not significantly altered when tested along the red-green and tritan confusion axes.ConclusionsAchromatic contrast sensitivity is significantly reduced following tropicamide administration at intermediate and high spatial frequencies [22].
• Distant visual acuities, colour vision and confrontation visual fields were assessed before and after pupillary dilatation with 2.5% phenylephrine and 1% tropicamide [23].

Anatomical context of Mydriacyl

• The time courses of changes in the effects of topical pilocarpine and tropicamide on the index of the blood-aqueous barrier permeability to plasma protein (Pin) were determined in normal volunteers [24].
• 4-DAMP, pirenzepine, tropicamide and methoctramine displaced [3H]NMS in CHO m5 membranes with pK50 values of 9.20+/-0.14, 6.59+/-0.04, 6.89+/-0.05 and 7.22+/-0.01 respectively [25].
• Why patients with Alzheimer's disease may show increased sensitivity to tropicamide eye drops: role of locus coeruleus [16].
• In the tropicamide study, there was a mean arteriolar constriction of 8.1% (SEM 1.67, p less than 0.001) and venule constriction of 3.7% (SEM 0.85, p less than 0.001) with a mean rise in diastolic blood pressure of 27.4 mmHg (SEM 2.95, range: 13-45 mmHg) [26].
• Little or no changes in neutrophil locomotion were seen with atropine, homatropine, scopolamine or tropicamide when tested at the same concentration range [27].

Associations of Mydriacyl with other chemical compounds

• METHODS: Ten normal human volunteers underwent dilation with tropicamide, phenylephrine, and a combination of the two drugs [28].
• The results indicated that pilocarpine increased the blood-aqueous barrier permeability to plasma protein in a dose-dependent manner and that tropicamide reduced it [24].
• CONCLUSIONS: The potentiation of tropicamide-evoked pupil dilatation by clonidine may be due to the abolition of the increase in parasympathetically mediated pupil constriction due to reduced LC activity [16].
• The acute effect of topical phenylephrine HCl 10%, tropicamide 1% and proparacaine HCl 0.5% on macular capillary blood flow was studied in six healthy human volunteers using the blue field simulation technique [29].
• No statistically significant difference was found between the tropicamide and cyclopentolate cycloplegic refractions (mean difference in MSE +/- SD, OD=0.054 +/- 0.214 diopters (D), t=1.33, P=.10; OS=0.054 +/- 0.253 D, t=1.12, P=.14) [30].

Gene context of Mydriacyl

• The results show that none of the enantiomers is able to significantly discriminate among the receptors studied and therefore do not support the proposal of tropicamide as an M4 (m4) selective agent [31].
• Pupil dilation to tropicamide is not specific for Alzheimer disease [32].
• After dilation with tropicamide 1%, lens opacities were graded using the Lens Opacities Classification System (LOCS) III [33].
• To assess the ability of diabetic patients to drive after pupillary dilatation we studied 61 diabetic patients (18 IDDM, 43 NIDDM), mean age 54.98 years, before and 1 h after pupillary dilatation with 1% tropicamide [34].
• Four Kodachrome 64 photographs per eye were taken with a Canon CR4 - 45NM camera through tropicamide-dilated pupils; slides were projected and systematically graded [35].

Analytical, diagnostic and therapeutic context of Mydriacyl

• We administered a topical solution of 1% tropicamide to 30 adults to determine the course of pupillary dilation over time and whether adequate dilation could be attained within a routine clinic visit [36].
• Pupillary dilation in response to dilute tropicamide eye drops has been proposed as a noninvasive diagnostic test to identify patients with Alzheimer's disease (AD) [2].
• Based on these results, the most effective cutoff point of 0.005% tropicamide for differential diagnosis was 114.5% of the average pupil dilation rate for 60 min [37].
• In eyes predilated with tropicamide, iris massage caused marked pupillary constriction [38].
• The effects of pupillary dilation (tropicamide 1%) on automated static threshold perimetry were studied in 18 normal subjects using the Humphrey field analyzer 30-2 and STATPAC programs [39].

References