PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Eye Color”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,495 records · Page 83Linked to original sources
PubMed1980

Corneal metabolism of pilocarpine in pigmented rabbits.

Cornea, aqueous humor, and iris-ciliary body levels of pilocarpine and its metabolite pilocarpic acid were determined in mixed-breed rabbits following topical dosing with 25 microliters of 1 X 10(-2) M pilocarpine. From the time-drug concentration profile it is clear that extensive metabolism of pilocarpine occurs in the cornea of pigmented rabbits. This finding contrasts sharply with similar studies in albino rabbits where relatively low levels of pilocarpine acid were observed. It is estimated that the first-order metabolism rate constant in albino rabbits is approximately two orders of magnitude smaller than in pigmented animals. A significant observation from this finding is the possibility that the reported greater dose requirement for heavily pigmented individuals may not be due to drug-pigment binding alone but also to extensive corneal drug metabolism.

Animals↗
PubMed1993

Foveal cone ERGs in fellow eyes of patients with unilateral neovascular age-related macular degeneration.

PURPOSE: To determine whether fellow eyes with normal visual acuity of patients with unilateral neovascular age-related macular degeneration (AMD) have retinal malfunction. METHODS: Foveal cone electroretinograms (ERGs) were recorded from fellow eyes with visual acuities of 20/25 or better of 73 patients with unilateral neovascular AMD and from 28 normal volunteers of comparable age. Responses were elicited with a 4 degrees stimulus flickering at 42 Hz presented by a stimulator-ophthalmoscope. RESULTS: The study eyes of the patients were found to have foveal cone ERGs that, on average, were normal in amplitude but delayed in implicit (peak) time after adjustment of the data for age, sex, iris pigmentation, and refractive error by multiple linear regression. Based on all subjects, amplitude declined with increasing age and was smaller in eyes with darker irides; implicit time increased with increasing age. CONCLUSIONS: These findings suggest that fellow eyes with normal visual acuity of patients with unilateral neovascular AMD tend to have foveal cones that are normal in number but that function abnormally. In addition, foveal cone ERG amplitude should be adjusted for both age and iris pigmentation and implicit time should be adjusted for age when assessing retinal function of elderly patients.

Aged↗
PubMed1993

The effect of dapiprazole on accommodative amplitude in eyes dilated with 0.5 percent tropicamide.

BACKGROUND: Dapiprazole 0.5 percent (REV-EYES) eyedrops have recently become commercially available in the U.S. to reverse the diagnostic mydriasis produced by various concentrations and combinations of tropicamide and phenylephrine. Although a previous study has shown that dapiprazole increased accommodative amplitude after the administration of tropicamide, no attempt was made to control for differences in pupil size. METHODS: In the present single masked study, the accommodative amplitudes of forty-eight age-matched subjects previously dilated with 0.5% tropicamide were measured through a 3 millimeter artificial pupil following random instillation of dapiprazole in one eye and a placebo drop in the other eye. RESULTS: Area under the curve analysis determined that the magnitude of accommodative response to dapiprazole was significant at p < 0.001 (paired t-test). The McNemar test also showed that the accommodative amplitude was greater in eyes treated with dapiprazole at all observation points (p < 0.005), beginning at 15 mins after the instillation of the test drug. CONCLUSIONS: The results demonstrate that dapiprazole accelerates the return of accommodation independent of pupil size.

Accommodation, Ocular↗
PubMed1993

[Effect of low doses of emoxipine and pyridoxine hydrochloride on the status of patients with cataract and glaucoma].

It has been shown that eyes instillation of pyridoxine hydrochloride low doses during 20 days affects the vision and tonographic characteristics of patients with glaucoma and earlier stage of cataract. Light eyes have been shown to be more sensitive to treatment than dark ones. From 10 to 40 min after emoxipin or pyridoxine hydrochloride low doses instillation, some pupil constriction has been registered. The data obtained suggest that low doses of this substances affect eyes cholinoreactive structures and may be useful for treatment glaucoma and early stage cataract.

Cataract↗
PubMed1993

Effect of mutation on mating propensity in Drosophila biarmipes.

By using multiple-choice technique, mating success between purple eye colour mutant and wild type D. biarmipes was studied in an Elens-Wattiaux mating chamber. Red eyed (wild type) males were more successful in mating than mutant males. However, mutant females were more receptive than wild females. The results suggest that purple eye colour mutation affects mating propensity in D. biarmipes.

Animals↗
PubMed1993

Mydriatic efficacy of a cycloplegic spray in the pediatric population.

BACKGROUND: The topical administration of eyedrops is often an unpleasant procedure in the pediatric population. We sought to learn whether a combination mydriatic-cycloplegic solution would be an effective mydriatic if applied as a spray. METHODS: We used a prospective, examiner-masked, parallel-group study design and randomized 38 subjects (age range 6 months-12 years, mean = 7.3 years) into four groups such that the same combination mydriatic-cycloplegic solution was administered under the following conditions: 1) eyedrops to eyes that were closed; 2) eyedrops to eyes that were open; 3) spray to eyes that were closed; 4) spray to eyes that were open. Both eyes of each subject received the solutions administered under one of the four conditions. Photographs were taken of each subject's pupils at times 0, 5, 15, 25, 40, and 55 mins following administration of the medications. RESULTS: Repeated measures analysis of variance revealed no statistically significant difference (p > 0.05) in mydriatic efficacy among the four methods of drug administration. CONCLUSIONS: The results of this study suggest that the mydriatic efficacy of a mydriatic-cycloplegic spray is comparable to that associated with eyedrop instillation. Mydriatic sprays may have important clinical advantages over conventional ophthalmic solutions in the pediatric population.

Aerosols↗
PubMed1993

Fair complexion and risk of malignant melanoma of the skin based on experience from the Danish Cancer Registry.

Our Danish study shows that many pigmented naevi, a tendency to freckle and light hair colours are significant, important, and independent host factors which increase the risk of development of malignant melanoma of the skin. These results are in line with what has been consistently shown in previous and in more recent case-control studies. Light hair colour may be a measure of light complexion. The finding that individuals with a large number of naevi, a tendency to freckle and a sensitive skin constitute a risk group may be of importance. Such individuals could be warned about signs of early melanoma development and be instructed to avoid excessive sun exposure, especially damaging sunburn, with the aim of reducing melanoma mortality and melanoma incidence, respectively.

Adult↗
PubMed1995

[The dependence of the parasympathetic reaction of the mesencephalic section of the brain stem to age-, sex- and pigment-reagent-related factors].

Photoelectron pupillograph measurements of pupillary responses to light were made in 198 healthy individuals. Photoreaction of the pupils was declining with age contrary to the reciprocity rate which was stable (3.01-3.56). It indicates on the relative stability of parasympathetic-sympathetic relations. Young males with hyperpigmented irises had hyperactive parasympathetic reaction which sharply decreased to normal values at the age of 26-30 years. Estimated standard values of time, strength and speed of pupillomotor reaction can be used for comparative evaluation of autonomic neuromotor and brain structures involvement in various neurological diseases. These values may serve as initial point for devising medical algorithms and computer programs.

Adolescent↗
PubMed1995

Visual search: eye movements and peripheral vision.

The visual search task allows investigation of the way in which central processes can influence the programming of saccadic eye movements. In this paper, a simple search task is studied in which a target is presented in a ring-shaped display of eight stimuli. The subject is required to locate the target with a saccadic eye movement. Targets were colored disks and the task was to search for a target of a particular color. Sensory factors (when all nontargets are identical, the target stands out) and central factor (prespecification of the target) both contribute to search efficiency. When the display contains a double target, saccades sometimes land at an intermediate position between the two targets. This shows that the signal delivered by the search procedure is not necessarily highly localized.

Adult↗
PubMed1996

Comparison of argon laser iridotomy and sequential argon laser and Nd:YAG laser iridotomy in dark irides.

BACKGROUND AND OBJECTIVE: A prospective study was performed to compare argon laser iridotomy and sequential argon laser and Nd:YAG laser iridotomy in dark irides. PATIENTS AND METHODS: Twenty-four eyes of 17 patients underwent laser iridotomies; 13 underwent argon laser iridotomies and 11 underwent sequential argon laser and Nd:YAG laser iridotomies. The argon laser settings were standardized at 1.2 W, 50-mum spot size, and 0.1-second duration. The Nd:YAG laser was set at 2.5 mJ and single-pulse shots were used. RESULTS: All of the iridotomies were patent at the end of one treatment session. The mean total energy used for argon laser iridotomy was 8.28 J. For sequential iridotomy, 3.12 J was used for the argon laser stage and 7.5 mJ for the Nd:YAG laser stage. CONCLUSION: The total argon laser energy used can be reduced by 2.65 times by using the sequential laser iridotomy technique.

Aged↗
PubMed1996

Estimating equations for measures of association between repeated binary responses.

Moment-based methods for analyzing repeated binary responses using the marginal odds ratio as a measure of association have been proposed by a number of authors. Carey, Zeger, and Diggle (1993, Biometrika 80, 517-526) have recently described how the marginal odds ratio can be estimated using generalized estimating equations (GEE) based on conditional residuals (deviations about conditional expectations). In this paper, we show that other measures of association between pairs of binary responses, e.g., the correlation, can also be estimated using conditional residuals. We demonstrate that the estimator of the correlation based on conditional residuals is nearly efficient when compared with maximum likelihood or second order estimating equations (GEE2) except when the correlation is large. This estimator also yields more efficient estimates of the correlation than the usual GEE estimator that is based on unconditional residuals. Furthermore, the gains in efficiency can be quite considerable when some of the responses are missing or incomplete, or, alternatively, when cluster sizes are unequal (in the clustered data setting).

Air Pollution↗
PubMed1996

Effect of commercial dilating agents on laser flare-cell measurements.

OBJECTIVE: To compare the effect of tropicamide alone and tropicamide-phenylephrine on anterior chamber flare and cell measurements obtained with a laser flare-cell meter. DESIGN: Prospective study. SETTING: Gimbel Eye Centre, Calgary. SUBJECTS: Twenty white subjects (10 with blue irides and 10 with brown irides) aged 24 to 45 (mean 30.2) years without any known systemic or ocular disease. INTERVENTIONS: Laser flare-cell measurements were obtained 30 minutes after pupillary dilation with 1% tropicamide in one eye and a combination drop of 0.8% tropicamide and 5% phenylephrine in the other eye. The average of five readings was taken for each eye. OUTCOME MEASURES: Flare and cell measurements. RESULTS: There was no statistically significant difference in flare photon count or cell count between the eyes dilated with tropicamide and those dilated with tropicamide-phenylephrine. In addition, iris colour was not found to have a significant effect on flare and cell measurements. CONCLUSIONS: Our results suggest that pupillary dilation for laser flare-cell measurements can be done with either mydriatic agent in healthy white subjects of any eye colour without significant effects on the measurements. Further study is needed to determine whether the same is true in older subjects.

Administration, Topical↗
PubMed1996

Comparison of efficacy and tolerance between 1% hydroxyamphetamine plus 0.25% tropicamide (Paremyd) and 0.5% tropicamide combined with 2.5% phenylephrine.

BACKGROUND: Paremyd, consisting of a combination of 1.0 percent hydroxyamphetamine and 0.25 percent tropicamide, is a commercially available eyedrop used clinically for diagnostic mydriasis. This study sought to determine if one drop of Paremyd is equally effective and tolerable as the traditional combination of one drop each of 2.5 percent phenylephrine and 0.5 percent tropicamide. METHODS: A prospective, double-masked, randomized, cross-over study was conducted in 60 normal volunteers ranging from age 20 to 35 years (mean 24.3 years). Twenty-two subjects (36.7 percent) were male, and 32 subjects (53.3 percent) had brown irides. Pupil diameter, amplitude of accommodation, distance and near visual acuity, and subjective comfort of eyedrop instillation were assessed for 8 hours following drug instillation. RESULTS: Significantly more subjects (p < 0.05) experienced adverse ocular symptoms with the tropicamide plus phenylephrine (TP) combination than with Paremyd (P). There was no statistically significant (p > 0.05) difference in mydriatic response between TP and P. During the first hour, however, TP and P demonstrated significant (p = 0.001) differences in cycloplegic effect. CONCLUSIONS: Paremyd appears to be as effective a mydriatic as TP, but with greater comfort on instillation. Paremyd has less effect on accommodation.

Accommodation, Ocular↗