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PubMed1981

Anterior chamber lenses and severe segmental uveal ectropion.

Seven cases of severe segmented uveal ectropion are presented. This is a color change of the iris which appears to be caused by pigment eipthelium being pulled from the pupillary margin to the footplates under a Tennant or Mark VIII anterior chamber lens. It was found in 1-2% of cases followed by the author for at least two to three years after lens implant. All eyes have poorly reactive pupils but seemingly well-fitting IOLs and good visual acuity to date. An hypothesis for its pathophysiology is presented which promotes ischemic atrophy with subsequent fibrosis of the iris as the involved mechanisms.

Aged↗

PubMed1986

Effect of phenylephrine on accommodation.

We studied the effect of the topical instillation of phenylephrine hydrochloride on accommodation. Factors considered were iris color and the influence of the prior application of a topical anesthetic. There has been controversy concerning the role of the sympathetic nervous system in accommodation. Our results indicate that the sympathetic nervous system does influence accommodation. Prior application of an anesthetic prolongs the effect of phenylephrine on the accommodation and on pupil diameter in eyes with either lightly or more heavily pigmented irides.

Accommodation, Ocular↗

PubMed2004

Quantitative assessment of videokeratography data using fourier series harmonic analysis.

PURPOSE: To describe a method of mathematically decomposing videokeratography data using Fourier series harmonic analysis and present examples of its clinical application. METHODS: Videokeratography data were decomposed by Fourier analysis into spherical component, regular astigmatism, asymmetry (decentration or skewness), and higher-order irregular astigmatism. These 4 Fourier components were analyzed in both normal and pathologic eyes. Color-coded maps were generated to present the 4 Fourier components. RESULTS: Color-coded mapping of the results of Fourier analysis of videokeratography data facilitated visual and instant interpretation of complex corneal topographic information. By using Fourier components, time course of changes in corneal topography following penetrating keratoplasty and influence of suture removal were quantitatively evaluated. The Fourier analysis method was successfully applied to determine the most appropriate correction lenses in eyes after penetrating keratoplasty. CONCLUSIONS: Fourier analysis of videokeratography data allows mathematical separation of regular and irregular astigmatism and is useful in the quantitative assessment of corneal optics in eyes with both pathologic and postsurgical conditions.

Adult↗

PubMed1999

[Color and form changes in the iris].

BACKGROUND: The high variability of iris structures can be used for diagnostic purposes. METHODS: An overview of the numerous changes visible at the slit lamp and possible diagnosis. RESULTS: Short description of possible irispathology with hints on pathology and treatment.

Diagnosis, Differential↗

PubMedDate not supplied

Platinum coat color locus in the deer mouse.

Platinum coat color in the deer mouse, Peromyscus maniculatus, is an autosomal recessive trait marking a locus, pt, distinct from silver (si), albino (c), blonde (bl), brown (b), and agouti (a). Platinum deer mice are conspicuously pale, with light ears and tail stripe. The pewter trait is allelic with and phenotypically identical to platinum, and represents an independent recurrence of this mutant. The rate of recoveries of coat color mutations from wild deer mice is consistent with available data for recurring mutation rates balanced by strong selection against the recessive phenotype.

Alleles↗

PubMed1993

Two visual systems in one brain: neuropils serving the secondary eyes of the spider Cupiennius salei.

Like other araneans, the wandering spider Cupiennius salei is equipped with one pair of principal eyes and three pairs of secondary eyes. Primary and secondary eyes serve two distinct sets of visual neuropils in the brain. This paper describes cellular organization in neuropils supplied by the secondary eyes, which individually send axons into three laminas resembling their namesakes serving insect superposition eyes. Secondary eye photoreceptors send axons to small-field projection neurons (L-cells) which extend from each lamina to supply three separate medullas. Each medulla is a vault of neuropil comprising only a few morphological types of neurons. These can be compared to a subset of retinotopic neurons in the medullas of calliphorid Diptera supplying giant motion-sensitive neurons in the lobula plate. In Cupiennius, neurons from secondary eye medullas converge at a single target neuropil called the "mushroom body." This region contains giant output neurons which, like their counterparts in the calliphorid lobula plate, lead to descending pathways that supply thoracic motor circuits. It is suggested that the cellular arrangements serving Cupiennius's secondary eyes are color independent pathways specialized for detecting horizontal motion. The present results do not support the classical view that the spider "mushroom body" is phylogenetically homologous or functionally analogous to its namesake in insects.

Animals↗

PubMed1986

[Genetical analysis and characterization of a new mutant, black tremor appearing in the Syrian hamster].

A black coat-color mutant with tremor was discovered in babies of 61 generations of an inbred strain APG of Syrian hamster which had been maintained in the Nippon Institute for Biological Science, Laboratory Animal Research Station. The genetical analysis by matings between four inbred strains which had different genes in the E and B loci and four mutant strains which were introduced the mutant gene into the four inbred strains and characterization were carried out on the mutant. The results obtained are summarized as follows: 1) The mutation occurred in a different locus with E and B loci. 2) The mutant was controlled by an autosomal recessive gene designated as "bt", and it was thought that both tremor and black coat-color were the pleiotropic effect of bt gene. 3) At least one E gene in the E locus was necessary for the appearance of black coat color. Therefore, the coat-color remained cream in ee (cream) hamsters showing only trembling. 4) The degree of blackness of the coat-color of EE hamsters differed from Ee ones. The former was darker than the latter. 5) The mutant may be a useful animal model for studying abnormal myelogenesis and biosynthesis of melanin.

Animals↗

PubMed1990

Time course of cycloplegia induced by a new phenylephrine-tropicamide combination drug.

A motorized and computer-interfaced phoropter was used to track the development of cycloplegia and recovery of accommodation over a 60-min period, after the topical application of a phenylephrine 5%-tropicamide 0.8% drug combination (Phenyltrope). Phenyltrope was introduced into the Canadian market about 2 years ago (Compendium of Pharmaceuticals and Specialties, 1987), and advertised as a fast acting cycloplegic and mydriatic drug. Here we report the results of our investigation of the depth of action and the temporal aspects of cycloplegia for this drug combination as a function of iris color. We also compare the action spectrum of Phenyltrope to that of tropicamide 1% under similar test conditions. Our results indicate that the latency for cycloplegia was shorter for tropicamide, the maximum rate of accommodative loss similar for both drugs, and the resultant cycloplegia at 20 min deeper for Phenyltrope. Recovery from induced cycloplegia was greater for tropicamide 60 min after drug administration. For both Phenyltrope and tropicamide, no significant differences in any of the parameters investigated were observed as a function of iris color. We conclude that even though Phenyltrope induced a measurably deeper cycloplegia than did tropicamide, the amount of residual accommodation present at 20 min (about 38%) is insufficient for most refractive purposes.

Accommodation, Ocular↗

PubMed1983

[Nomenclature of iris color].

Heterochromia simplex (Streiff) or true heterochromia of the iris (H. vera, H. congenita) is the product of mosaic inheritance arising from variable expressivity of the parental characteristics. This is different from the "mixed iris", which shows a mixture of colours, in which the components are no longer distinguishable but form a new shade.

Eye Color↗

PubMed1993

1% Cyclopentolate hydrochloride: another look at the time course of cycloplegia using an objective measure of the accommodative response.

The time course of cycloplegia was measured by monitoring residual accommodation after the application of 1 drop (29.3 microliters) of 1% cyclopentolate hydrochloride. Three different measures of residual accommodation were made, one objective assessment with an optometer, and two subjective assessments similar to those used by previous investigators. Pupil diameter was also measured in a subgroup of individuals to compare the time course of the induced mydriasis to that of the cycloplegia. When residual accommodation is measured objectively, maximum cycloplegia occurs 10 min after the application of 1% cyclopentolate hydrochloride in individuals with light irides. This result suggests that the standard clinical protocol of delaying refraction 30 to 60 min after the application of cyclopentolate hydrochloride may be too conservative for individuals with light irides. For individuals with dark irides, 30 to 40 min is required for maximum cycloplegia, and the magnitude of residual accommodation in these individuals is similar to that found in light iris individuals at 10 min. When subjective measures are used to estimate residual accommodation, more accommodation is present and the time at which maximum cycloplegia occurs is delayed for individuals with light irides. These results are in agreement with previous studies using subjective techniques. Regardless of iris color or measurement method, the time course for pupil dilation is not the same as the time course for cycloplegia.

Accommodation, Ocular↗

PubMed2000

Race, iris color, and age-related macular degeneration.

PURPOSE: While most observers agree that age-related macular degeneration (AMD) is much more common in white persons than in persons of black African ancestry, the influence of iris color has been more controversial. We reexamined relationships between race, iris color, and AMD in a series of patients from our retina clinic. METHODS: We evaluated, in masked fashion, stereoscopic photographs of the retinas and irides in 306 sequential patients 60 years of age or older from our retina clinics. Four readers judged whether AMD was present, absent, or questionable in the retinal photographs and labeled iris color as blue, hazel, or brown. Presence or absence of AMD and presence and severity of the various macular lesions were determined by "majority vote" of the readers. We evaluated inter-rater agreement using the kappa statistic. We compared the prevalence of AMD and of specific AMD lesions as a function of race, sex, and iris color by contingency table analysis. RESULTS: The kappa statistic showed good inter-observer agreement, being 0.466 (P < 10(-6)) for definite or questionable AMD and ranging from 0.185 to 0.522 (P = 0.0047 to P < 10(-6)) for most lesions. We found significantly more AMD in white patients than in black patients (X2 = 27.54, P < 10(-4)). There was no significant difference in AMD prevalence by sex. In white patients, AMD was significantly more prevalent in individuals with blue or hazel irides than in those with brown irides (X2 = 15.04, P = .02). CONCLUSIONS: We confirm previous findings of a higher prevalence of AMD in white persons than in black persons. We also agree with those observers who claim that white subjects with light-colored irides have a higher prevalence of AMD than those with dark-colored irides. We suggest that differences in the association between iris pigmentation and AMD in different studies using different research methods may reflect genetic difference in the groups being studied.

Black or African American↗

PubMed1984

Color as a risk factor in iris melanoma.

We reviewed 23 iris melanomas for iris color and gross tumor pigmentation. Patients with iris melanoma had lighter irides than both population controls (x2 = 58.0; P less than .0001) and other patients with uveal melanoma (x2 = 17.1; P = .002). Amelanotic and lightly melanotic tumors occurred predominantly in the patients with light irides.

Eye Color↗

PubMed1988

Natural course of melanocytic tumors of the iris.

The authors received the charts and photographs of 175 patients who had suspicious melanocytic lesions of the iris and who were followed without treatment. Only eight (4.6%) of these lesions showed clinical evidence of enlargement during follow-up intervals of 1 to 12 years (mean, 4.7 years). Features that were associated with enlargement of the lesion included medial location of the mass on the iris and presence of pigment dispersion onto the adjacent iris and anterior chamber angle structures. Features that were unassociated with growth of the lesion included patient age and sex, intraocular pressure, iris color, tumor size and vascularity, and presence of pupillary distortion, ectropion iridis, and sector cataract. From these results, recommendations are made which can assist the ophthalmologist in the management of pigmented iris lesions.

Adult↗

PubMed2006

A novel homozygous GRK1 mutation (P391H) in 2 siblings with Oguchi disease with markedly reduced cone responses.

PURPOSE: The only mutations reported to date in Japanese patients with Oguchi disease, a rare form of stationary night blindness with autosomal recessive transmission, have been in the SAG (arrestin) gene. The objective of this study was to describe the ophthalmic features and a novel mutation in the GRK1 (rhodopsin kinase) gene in 2 Japanese patients with Oguchi disease. DESIGN: Molecular genetic and observational case study. PARTICIPANTS: A consanguineous family including 2 siblings with Oguchi disease (a 35-year-old man and a 31-year-old woman). METHODS: Best-corrected visual acuity (BCVA), fundus examinations, Goldmann perimetry, color vision tests, and full-field electroretinograms (ERGs) were evaluated. Mutation screening of the SAG and GRK1 genes was performed with polymerase chain reaction amplification and direct sequencing. MAIN OUTCOME MEASURES: Mutations in the GRK1 gene, BCVA, color vision, fundus photographs, visual fields, and ERG findings. RESULTS: Molecular analysis revealed a novel homozygous missense mutation (p.P391H) in the GRK1 gene in both patients. Proline 391 is not only within the functionally important catalytic domain, but is also a phylogenetically conserved amino acid residue among GRK1 orthologs and homologs. No mutation was found in the SAG gene. The unaffected parents were heterozygous carriers of the mutation. Both patients had night blindness, 1.5 BCVA for each eye, normal color vision, and typical fundus appearance with golden-yellow discoloration. The visual fields were normal in the male sibling. The ERGs showed no rod B waves, reduced standard combined responses, and markedly reduced single-flash cone and 30-Hz flicker responses in both patients. CONCLUSIONS: A novel homozygous GRK1 mutation (p.P391H) was found in 2 Japanese siblings with Oguchi disease. Visual function in the 2 patients has not deteriorated with age, indicating that the disease is stationary. This is the first report of any patient with GRK1-associated Oguchi disease with markedly reduced cone responses.

Adult↗

PubMed2002

Color naming and the phototoxic effects of sunlight on the eye.

Many languages have no basic color term for "blue." Instead, they call short-wavelength stimuli "green" or "dark". We show that this cultural, linguistic phenomenon could result from accelerated aging of the eye because of high, chronic exposure to ultraviolet-B (UV-B) in sunlight (e.g., phototoxic lens brunescence). Reviewing 203 world languages, we found a significant relationship between UV dosage and color naming: In low-UV localities, languages generally have the word "blue"; in high-UV areas, languages without "blue" prevail. Furthermore, speakers of these non-"blue" languages often show blue-yellow color vision deficiency. We tested our phototoxicity hypothesis in a color-naming experiment, using computerized, colorimetric simulations of Munsell colors as viewed through clear and brunescent lenses. As predicted, our young subjects used "blue" as in English when the simulated lens was clear, but named colors as in tropical languages when the lens was dense. Our within-subjects design precludes a cultural explanation for this result.

Adolescent↗

PubMedDate not supplied

The foundation of experimental ophthalmology by Theodor Leber.

Theodor Leber grew up in Heidelberg as the son of a professor of Romance languages. Initially he planned to study natural sciences. Bunsen's advice led him to medicine. During his studies he succeeded in solving a competition problem posed by Helmholtz in the medical department. A short period of practical work in the eye hospital of Knapp was unsatisfactory. In Vienna with the physiologist Carl Ludwig, he was able in 1863/64, at the age of only 24 years, to demonstrate the blood circulation of the eye by color injections into the arteries and veins. Since that time the schematic drawings of his results can be found in every textbook of ophthalmology. On the occasion of the congress of the German Ophthalmological Society in Heidelberg in 1864, Theodor Leber reported on these findings and met with immense approval. In 1864-67 he followed an invitation as coworker of Liebreich to Paris; in 1867 he became A.v. Graefe's coworker in Berlin; in 1871 he moved to Göttingen, which became the first eye clinic with a laboratory for experimental investigations. The second epoch-making discovery accomplished by Leber was the detection of the fluid exchange in the eye. These results have also been confirmed by modern methods. Therefore, Theodor Leber can be called the father of experimental ophthalmology.

Animals↗

PubMed2000

[The study of tarnish induced by Actinobacillus actinomycetemcomitans serotype b (Aay4) on titanium and Ti-75 alloys].

OBJECTIVE: To study the tarnish induced by Aay4 on titanium and Ti-75 alloys. METHODS: Pure titanium and Ti-75 alloys were machined into size of 10 mm x 10 mm x 1 mm in tablets(30 of pure titanium; 60 of Ti-75 alloys). Thirty specimens sampled randomly from Ti-75 alloy together with 30 specimens of titanium were subjected to chemical passivation treatment. 30 specimens of the pure titanium, depassivation Ti-75 alloy and passivation Ti-75 alloy were randomly divided into three groups (blank control group, media control group and inoculated media group) respectively, every group contains 10 specimens. Under the anaerobic conditions, the surfaces of the modified GAM media were inoculated with Aay4. The labeled specimens surfaces were then aseptically placed on top of the media surface for 10 weeks with one generation time per week. The specimens were removed after 10 weeks of incubation, immersed in 0.05% glutaradehyde solution to eliminate Aay4, rinsed with distilled water. After 2 weeks, the specimens were removed and observed visually or examined by MINOLTA CR-100 color apparatus. RESULTS: Visual evaluation: Aay4 caused significant tarnish on specimens exposed to inoculated media, all the specimens surface changed into yellow color. Color apparatus evaluation: this result showed that comparing with the blank control, media control has no influence on all the specimens L*a*b* values (P > 0.05). Aay4 caused significant tarnish on specimens exposed to inoculated media, the result showed that there was significant difference between media control group and blank control group with inoculated media group on all the specimens L*a*b* values (P < 0.05). CONCLUSION: Aay4 caused significant tarnish on pure titanium, depassivation Ti-75 alloys and passivation Ti-75 alloys by naked eyes and color apparatus, according CIE1976L*a*b* color system reading, the color of titanium and Ti-75 alloys changed from the yellow-green ranges to red-yellow ranges.

Aggregatibacter actinomycetemcomitans↗

PubMed1999

alpha-Methyl-p-tyrosine inhibits latanoprost-induced melanogenesis in vitro.

The PGF2alpha derivative, latanoprost, is a recent anti-glaucoma drug that has been reported to induce a discrete incidence of increased iris pigmentation in men. The present experiments were made in order to study whether this phenomenon could be influenced by the tyrosinase inhibitor, alpha-methyl-p-tyrosine. Melanin content, melanin production and tyrosinase activity of cultured uveal melanocytes derived from irides of brown or brown-blue color were measured after adding latanoprost at different molar concentration with or without alpha-methyl-p-tyrosine (10(-5)m). It was shown that latanoprost stimulated melanin content, melanin production and tyrosinase activity in a molar range between 10(-7) and 10(-5)m in uveal melanocytes derived from irides of both brown and brown-blue color. The effect seemed to be more pronounced in melanocytes derived from irides of brown-blue color. The adding of alpha-methyl-p-tyrosine completely prevented latanoprost-induced stimulation of melanin production in uveal melanocytes derived from irides of both colors. These results suggest that latanoprost-induced stimulation of melanin production, follows the metabolic pathway involving tyrosinase activity and may be relevant for the therapeutic application of latanoprost in glaucoma in order to reduce its side-effect resulting in increased iris pigmentation.

Cells, Cultured↗