Blue Irises Research Articles

Association of behavioral inhibition with hair pigmentation in a European sample

Behavioral inhibition, a temperamental trait signalling a predisposition to childhood and adolescent anxiety disorders, is slightly more frequent in America among Caucasian children having blue irises. This paper examines a community sample of 101 German toddlers assessed for behavioral inhibition in a standardized laboratory procedure. Hair pigmentation was found to be significantly associated with behavioral inhibition in the sense that blond children exhibited higher fear scores. As in American samples, blue-eyed children had a higher fear score than did other children, but this difference was not statistically significant.

Iris color and age‐related changes in lens optical density⋆

Summary Purpose: Epidemiologic evidence indicates that dark iris color increases risk of age‐related cataract. No information is currently available, however, on the effects of iris color on the lens prior to cataract development. In this study, we relate iris color to lens optical density (OD) in individuals without frank cataract. Methods: 90 subjects with blue or green irises (light color) were compared with 87 subjects having hazel, brown, or black irises (dark color). Lens OD was measured psychophysically by comparing scotopic thresholds obtained at 410 (measuring) and 550 nm (reference). Stimuli were presented in Maxwellian view. Results: The groups with light and with dark iris color did not differ significantly in smoking habits, dietary patterns, or age. Despite other similarities between the groups, lens OD was significantly(p<0.024) higher in the group with dark irises. The higher OD of the dark iris group was due to differences in the older subjects (>45 years,p<0.005), rather than the younger subjects (20–45 years) who showed no differences in lens OD. Conclusion: Our data indicate that iris pigmentation may be directly related to age‐associated increases in lens OD.

Iris color and age-related changes in lens optical density

Epidemiologic evidence indicates that dark iris color increases risk of age-related cataract. No information is currently available, however, on the effects of iris color on the lens prior to cataract development. In this study, we relate iris color to lens optical density (OD) in individuals without frank cataract. 90 subjects with blue or green irises (light color) were compared with 87 subjects having hazel, brown, or black irises (dark color). Lens OD was measured psychophysically by comparing scotopic thresholds obtained at 410 (measuring) and 550 nm (reference). Stimuli were presented in Maxwellian view. The groups with light and with dark iris color did not differ significantly in smoking habits, dietary patterns, or age. Despite other similarities between the groups, lens OD was significantly (p < 0.024) higher in the group with dark irises. The higher OD of the dark iris group was due to differences in the older subjects (> 45 years, p < 0.005), rather than the younger subjects (20-45 years) who showed no differences in lens OD. Our data indicate that iris pigmentation may be directly related to age-associated increases in lens OD.

Iris color as a prognostic factor in ocular melanoma.

Ocular melanoma may be more prevalent among patients with light irises than those with dark irises. To examine a large clinical series of patients with intraocular melanoma to determine if light irises are associated with increased risk of death from these tumors. A total of 1162 patients treated with proton irradiation between 1984 and 1996 were observed through 1997. Iris color in the patients was blue or gray in 48%, green or hazel in 30%, and brown in 23%. Tumors in patients with blue or gray irises were less heavily pigmented (P<.001) and closer to the optic disc and macula (P<.001). Five- and 10-year metastasis-related death rates were 0.14 and 0.21, respectively, for those with blue or gray irises and 0.10 and 0.15, respectively, for those with darker irises (P = .02). In a Cox proportional hazards regression controlling for tumor characteristics, patients with blue or gray irises died of metastatic disease at a rate 1.90 times (95% confidence interval, 1.26-2.85) that of patients with brown irises. The rate of metastatic death was not significantly elevated for those with green or hazel irises (relative risk, 1.43; 95% confidence interval, 0.91-2.23). Patients with blue or gray irises appear to be at increased risk of metastatic death from choroidal melanoma, independent of other risk factors.

Different Iris Coloration and Uptake of a Fluoroquinolone Agent into the Iris Ciliary Body of Rabbit Eyes

In order to know the correlation of a drug with high affinity to melanin in the iris ciliary body with the amount of melanin contained in the iris ciliary tissues, an in vivo study was performed on pigmented rabbits with brown or blue irises and albino rabbits. The melanin concentrations in the iris ciliary bodies of pigmented rabbits with brown and blue irises and nonpigmented rabbit eyes with whitish irises were determined. The mean concentrations of melanin in the eyes with brown-, blue- and whitish-colored irises were 47.43, 34.73 and below 0.2 microgram/mg tissue, respectively. The amount of sparfloxacin uptake in the iris ciliary bodies of eyes with brown, blue and whitish irises administered as 40 microliters of 0.3% solution 5 times every 5 min was 15.46 +/- 2.07, 8.53 +/- 1.87 and 1.9 micrograms/g, respectively. The results may be useful for intraocular drug dynamics studies.

Iris pigmentation and behavioral inhibition.

Two independent investigations of the association between the temperamental dimensions of inhibition and lack of inhibition to the unfamiliar, on the one hand, and the degree of pigmentation of the iris, on the other, revealed a statistically significant relation in Caucasian children between behavioral inhibition to the unfamiliar and blue irises and uninhibited behavior and brown irises. Several biochemical interpretations of this association were discussed and it was suggested that these behavioral styles might be influenced by biological factors that are partially marked by eye color in Caucasian populations.

Experimental photocoagulation of the human retina. I. Correlation of physical, clinical, and pathologic data.

Thirty-eight retinal burns were inflicted by a modified xenon-arc photocoagulator in the eyes of eight human volunteers. The ophthalmoscopic characteristics of these lesions were correlated with the degree of histopathologic damage. Definitive clinical criteria that helped to predict the severity of the retinal burns were established. The dose of radiant energy received was further correlated with the histopathologic changes in determining the threshold of safety standards of bright flashes of white light to the human eye. Lesions from patients with blue irises were produced by considerably higher dose rates than comparable lesions from patients with brown irises and the fovea was more susceptible to damage than the rest of the retina.

Biomicroscopic appearance of a formation encountered in certain blue irises

Biomicroscopic appearance of a formation encountered in certain blue irises