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 1,027 records · Page 57Linked to original sources
PubMed2000

Scotopic measurement of normal pupils: Colvard versus Video Vision Analyzer infrared pupillometer.

PURPOSE: To prospectively measure the scotopic pupil diameter in a normal population and to compare 2 infrared pupillometers for these measurements. SETTING: Johann Wolfgang Goethe-University, Department of Ophthalmology, Frankfurt am Main, Germany. METHODS: The Colvard infrared pupillometer was compared to the Video Vision Analyzer (VIVA) infrared pupillometer under scotopic light conditions in 33 participants (aged 19 to 55 years). Reliability was assessed by 2 independent examiners (E1, E2). Statistical analysis was performed using a comparison method by Bland and Altman. RESULTS: Mean pupil diameter was 6.16 mm +/- 1.20 (SD) (range 3.20 to 9.00 mm) with all measurements taken under scotopic illumination. The mean scotopic pupil diameter was 6.08 +/- 1.16 mm (range 3.2 to 8.4 mm) with the Colvard pupillometer and 6.24 +/- 1.28 mm (3.5 to 9.0 mm) with the VIVA pupillometer. The mean differences between the Colvard and VIVA were -0.27 mm (E1) and -0.05 mm (E2). Limits of agreement ranged from 1.4 (Colvard) to 2.4 (VIVA). The coefficients of repeatability ranged from 0.7 (Colvard) to 1.1 (VIVA). CONCLUSIONS: A mean scotopic pupil diameter of 6.15 mm with a maximal pupil size of 9.00 mm can be expected in a normal population; this should be considered in refractive corneal and refractive lens surgery. Measurements with the Colvard pupillometer were more reliable and precise than those with the VIVA pupillometer.

Adult↗
PubMed1992

Maximal mydriasis evaluation in cataract surgery.

We propose the maximal mydriasis test (MMT) as a simple and safe means to provide the cataract surgeon with objective and dependable preoperative information on the idiosyncratic mydriatic response of the pupil. The MMT results of a consecutive series of 165 eyes from 100 adults referred for cataract evaluation are presented to illustrate the test's practical applications and value. The results enable the surgeon to anticipate problem eyes preoperatively so he or she can plan an appropriate and effective surgical strategy. The MMT has also improved out cost-effectiveness by cutting down unnecessary delays in the operating room and enabling better utilization of restricted costly resources.

Administration, Topical↗
PubMed1998

Preoperative measurement of scotopic pupil dilation using an office pupillometer.

PURPOSE: To describe a light-amplification pupillometer designed for office evaluation of refractive surgical candidates and compare its usefulness with that of a millimeter ruler and a standard pocket-card pupillary gauge. SETTING: Center for Ophthalmic Surgery, Encino, California, USA. METHOD: The pupil sizes of 100 patients with a mean age of 28 years (range 18 to 50 years) were measured at 2 levels of illumination: 15 and 3 lumens. Pupil size was measured with a Rosenbaum pocket-card pupil gauge, a millimeter ruler, and the pupillometer at approximately 15 lumens. This level of illumination was chosen by 3 technicians as the lowest at which the pupil of a brown eye could be measured with confidence using the Rosenbaum card. Pupil size was then measured using the light-amplification pupillometer at approximately 3 lumens. This illumination level was chosen to simulate that of night-driving conditions. RESULTS: At 15 lumens, mean pupil diameter was 5.1 mm (range 2.5 to 8.0 mm). There was no difference in the measurements taken with the 3 instruments at this illumination level. At 3 lumens, the pupil diameter could not be measured with confidence using the Rosenbaum card or the millimeter ruler. Using the pupillometer, mean pupil size was 6.2 mm (range 3.0 to 9.0 mm). The mean difference in pupil diameter measured at 15 and 3 lumens was 1.1 mm (range 0.0 to 3.0 mm). CONCLUSION: This evaluation suggests that it would be difficult for clinicians to reliably predict the level of pupil dilation at 3 lumens by measuring pupil size at 15 lumens. The light-amplification pupillometer provides a tool for measuring pupil size at an illumination level that simulates night-driving conditions. The use of this device may help surgeons identify refractive surgery candidates who are more likely to be dissatisfied with their postoperative vision at low illumination levels.

Adolescent↗
PubMed1999

Black iris-diaphragm intraocular lens for aniridia and aphakia.

We present the first reported use in the United States of a black iris-diaphragm intraocular lens (IOL) for the treatment of traumatic aniridia and aphakic bullous keratopathy. The patient presented to a university-based practice with contact-lens-intolerant aniridia and aphakia with painful bullous keratopathy from a failed corneal graft. He was treated with combined penetrating keratoplasty and transscleral fixation of an aniridia IOL. The patient's preoperative symptoms of debilitating glare and photophobia resolved substantially after surgery, despite mild postoperative inflammation that resolved. The symptoms associated with aniridia can be successfully treated with a black iris-diaphragm IOL; however, chronic low-grade inflammation has been reported with its use in some cases.

Adult↗
PubMed2000

Black diaphragm aniridia intraocular lens for congenital aniridia: long-term follow-up.

PURPOSE: To present long-term results of implantation of a black diaphragm aniridia intraocular lens (IOL) in eyes with congenital aniridia. SETTING: Eye Hospital, Heinrich-Heine-University, Düsseldorf, Germany. METHODS: Cataract surgery was performed in 19 eyes of 14 patients with congenital aniridia. The black diaphragm aniridia IOL was implanted in front of the capsular bag in the ciliary sulcus. Mean patient age was 30 years (range 10 to 59 years) and mean follow-up, 46 months (range 12 to 84 months). Before surgery, corneal epithelial disorders; corneal pannus; cataract; hypoplasia of the macula, optic nerve, or both; and nystagmus were present in all 19 eyes. Clinically detectable glaucoma was present in 5 eyes. RESULTS: Despite the presence of amblyopia and nystagmus, visual acuity improved in 14 of the 19 eyes. The main postoperative problems were glaucoma deterioration (4 of 19 eyes) or development (4 of 19 eyes), cystoid macular edema (2 of 11 eyes), chronic endothelial cell loss (3 of 11 eyes), and progression of corneal epithelial disorders (4 of 19 eyes). Glaucoma was controlled by medical or surgical therapy in all patients. Intraocular lens explantation was performed in 2 eyes with glaucoma. CONCLUSION: Implantation of the black diaphragm aniridia IOL improved visual acuity in the majority of patients with a variety of endogenous problems in addition to aniridia.

Adolescent↗
PubMed1994

Gene regulation. Insulating chromatin.

"Insulator elements" have been identified that define the limits of transcriptionally active chromatin domains, protecting them against the repressive influence of neighboring heterochromatin.

Animals↗
PubMed1994

Transgenic mice. Fade to grey.

Expression of different amounts of tyrosinase from varying numbers of transgenes rescues the coat colour and eye pigmentation of albino mice in an approximately dose-dependent manner.

Animals↗
PubMed1998

Not just pretty eyes: Drosophila eye-colour mutations and lysosomal delivery.

Analysis of Drosophila eye-colour mutations has made seminal contributions to the fields of genetics and biochemistry. Recent findings suggest that a subset of eye-colour genes is crucial for vesicular transport of proteins to pigment granules, specialized lysosomes of eye-pigment cells. Thus, classical work describing more than 85 eye-colour mutations and their genetic interactions offers a remarkable, untapped resource for the genetic analysis of protein delivery to lysosomes.

Animals↗
PubMed1999

Oxidation of 3-hydroxykynurenine to produce xanthommatin for eye pigmentation: a major branch pathway of tryptophan catabolism during pupal development in the yellow fever mosquito, Aedes aegypti.

This study concerns the metabolic pathways of 3-hydroxykynurenine in Aedes aegypti mosquitoes during development with emphasis on its oxidation pathway to produce xanthommatin during eye pigmentation. Oxidation of tryptophan to 3-hydroxykynurenine is the major pathway of tryptophan catabolism in Aedes aegypti, but 3-hydroxykynurenine oxidizes easily under physiological conditions, which stimulate the production of reactive oxygen species. Our data show that in Aedes aegypti, the chemically reactive 3-hydroxykynurenine is converted to the chemically stable xanthurenic acid by a transaminase-catalyzed reaction during larval development, while 3-hydroxykynurenine is transported to the compound eyes for eye pigmentation during pupal development. Our data suggest that (1) the transamination pathway of 3-hydroxykynurenine is down-regulated during the pupal development, (2) 3-hydroxykynurenine produced in other body tissues is actively transported to the compound eyes during the pupal stage, (3) the compound eye is the place where ommochromes are produced, and (4) formation of ommochromes results from nonenzymatic oxidation of 3-hydroxykynurenine in the compound eyes.

Aedes↗
PubMed2002

Misclassification due to body hair and seasonal variation on melanin density estimates for skin type using spectrophotometry.

Recent advances have enabled quite accurate estimations of cutaneous melanin density by spectrophotometry using reflectance of light at wavelengths 400 and 420 nm. Our purpose was to assess the effect of body hair and seasonal variation at the upper inner arm and buttock on measurements of melanin density. We estimated melanin density of 104 volunteers at 3-monthly intervals over 12 months both before and after shaving. Removing body hair at the upper inner arm had no effect, but substantially reduced melanin estimates at the buttock in men. Significant seasonal variation was only observed at the upper inner arm, with highest readings in summer-autumn. In case-control studies, misclassification due to body hair at the buttock and seasonal variation at the upper inner arm could affect the observed odds ratio substantially. However, both sources of error can be reduced by careful attention to key aspects of study design.

Adult↗
PubMed2003

Analysis of systematic effects on congenital sensorineural deafness in German Dalmatian dogs.

We have analysed the systematic influences, phenotypic colour markers and the additive genetic variation for congenital sensorineural deafness (CSD) in German Dalmatian dogs in order to help elucidate the importance of phenotypic breed characteristics for genetic differences of CSD. Linear animal models using restricted maximum likelihood methods were employed to estimate variance components. Data were obtained from all three German Dalmatian kennel clubs associated with the German Association for Dog Breeding and Husbandry (VDH). CSD was recorded by standardized protocols for brainstem auditory-evoked response (BAER). The material included 1899 German Dalmatian dogs from 354 litters in 169 different kennels. BAER testing results were from the years 1986 to 1999. Pedigree information was available for up to seven generations. The animal model regarded the fixed effects of sex, coat colour, eye colour, presence of patches, litter size, percentage of examined puppies per litter, kennel club, and inbreeding coefficient. The common environment of the litter and kennel as well as the additive genetic effect of the animal were taken into account as randomly distributed effects. The fixed effects of eye colour, percentage of puppies examined per litter and kennel club were significant in the mixed model analysis. A significant proportion of additive genetic variation could be shown despite corrections for phenotypic colour variants. The heritability estimate for CSD in German Dalmatian dogs was h(2)=0.27+/-0.07. The additive genetic correlation of CSD with presence of blue eyes was r(g)=0.53+/-0.41 and with presence of patches r(g)=-0.36+/-0.24. We concluded that additional genes other than those associated with phenotypic colour markers in German Dalmatian dogs significantly contribute to the occurrence of CSD.

Animals↗
PubMed2004

Deafness prevalence and pigmentation and gender associations in dog breeds at risk.

Hearing function was tested in dogs from breeds at risk for pigment-associated congenital sensorineural deafness - Dalmatian, English setter (ES), English cocker spaniel (ECS), bull terrier (BT), Australian cattle dog (ACD), whippet, Catahoula leopard dog, and Jack Russell terrier. Deafness prevalence was highest in Dalmatians and lowest in ECS. Phenotype correlation studies were performed in breeds with >100 brainstem auditory evoked responses (BAER) tested subjects. No gender differences were observed. No differences were seen between black- and liver-spotted Dalmatians, among the ES roan colour varieties, among the ECS parti varieties, or among the ACD colour varieties. Blue eyes were positively associated and patches were negatively associated with deafness in the Dalmatian. Blue eyes were also associated with deafness in the ES and ECS. White BT were more likely than coloured BT to be deaf. Having one or more parent's ear deaf was positively associated with deafness in Dalmatians, ES, and ECS.

Animals↗
PubMed2003

When the darker eye has the smaller pupil.

Waardenburg and congenital Horner syndromes are both recognized causes of congenital hypochromic iris heterochromia. Each has been linked to disruptions in the pathway of tyrosinase induction, thus leading to a deficiency in melanin production of the iris. These syndromes must be considered in the differential diagnosis of a patient presenting with heterochromia iridis. We present the case of a 20-month old boy afflicted with both congenital Horner syndrome and Waardenburg syndrome, type II. In contrast to the more common presentation of congenital Horner syndrome, the affected iris in this case was the darker of the two because of the effects of the concomitant Waardenburg syndrome on the contralateral iris pigmentation. We are unaware of any other cases presenting with both Horner and Waardenburg syndromes and believe that this case serves as an excellent opportunity to briefly review the pathophysiology involved with these disorders.

Anisocoria↗
PubMed1998

The Drosophila Polycomb group gene pleiohomeotic encodes a DNA binding protein with homology to the transcription factor YY1.

Genes of the Polycomb group (PcG) of Drosophila encode proteins necessary for the maintenance of transcriptional repression of homeotic genes. PcG proteins are thought to act by binding as multiprotein complexes to DNA through Polycomb group response elements (PREs); however, specific DNA binding has not been demonstrated for any of the PcG proteins. We have identified a sequence-specific DNA binding protein that interacts with a PRE from the Drosophila engrailed gene. This protein (PHO) is a homolog of the ubiquitous mammalian transcription factor Yin Yang-1 and is encoded by pleiohomeotic, a known member of the PcG. We propose that PHO acts to anchor PcG protein complexes to DNA.

Amino Acid Sequence↗
PubMed1997

Genotoxic activation of hydrazine, two dialkylhydrazines, thiourea and ethylene thiourea in the somatic w/w + assay of Drosophila melanogaster.

Genotoxic activation of hydrazine (HZ), two symmetrical dialkylhydrazines, namely, 1,2dimethylhydrazine and 1,2-diethylhydrazine (SDMH and SDEH), thiourea (TU) and ethylene thiourea (ETU) has been evaluated by means of the w/w + somatic assay of Drosophila. Both low bioactivation insecticide-susceptible (IS) and high biotransformation insecticide-resistant (IR) strains were used. The combined application of insecticide-susceptible and insecticide-resistant strains should, in principle, detect somatic cell recombinagens in the Drosophila melanogaster in vivo w/w + assay. The IS strain was more susceptible to toxicity induced by the test chemicals than the IR stocks. Its performance in the biotransformation of the chemicals tested was rather poor. TU was inactive in all strains. With the active compounds, spot frequencies increased approximately linearly with dose for each spot type. SDEH gave a strong positive result in all three female genotypes exposed. HZ, ETU and SDMH were overall weakly positive in the IR strain Haag-79 (HG-R). Interestingly, ETU was clearly positive in the IR Hikone-R (HK-R) strain. A comparison of the recombinagenic potencies between the active and the weakly positive compounds, and among strains, showed pronounced genotype-dependent differences between the low and the high bioactivation strains. The ability of Drosophila to express several procarcinogens in relation to insecticide-resistance after activation catalyzed by CYP450 enzymes is discussed.

1,2-Dimethylhydrazine↗