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Soft contact lens and corneal changes associated with Visine use.

Sixteen subjects were fit with Cibasoft clear daily wear contact lenses and were asked to use two drops of tetrahydrozoline (Visine) twice a day for 4 months on one eye. Visual acuity, lens coloration, and slit lamp results were compared to baseline data between the test and control eye of each subject. Visual acuity and lens coloration results showed statistically insignificant changes from baseline. However, clinically important changes in corneal integrity were noted in 26.7% of the subjects.

Administration, Topical↗

Moringua edwardsi (Moringuidae: Anguilliformes): cranial specialization for head-first burrowing?

The order Anguilliformes forms a natural group of eel-like species. Moringua edwardsi (Moringuidae) is of special interest because of its peculiar fossorial lifestyle: this species burrows head-first. Externally pronounced morphological specializations for a fossorial lifestyle include: reduced eyes, lack of color, low or absent paired vertical fins, elongated, cylindrical body, reduced head pores of the lateral line system, etc. Many fossorial amphibians, reptiles, and even mammals have evolved similar external specializations related to burrowing. The present study focuses on osteological and myological features of M. edwardsi in order to evaluate the structural modifications that may have evolved as adaptations to burrowing. Convergent evolutionary structures and possible relations with head-first burrowing, miniaturization, feeding habits, etc., were investigated. Body elongation, reduction of the eyes, modified cranial lateral line system, and modified skull shape (pointed though firm) can be considered specializations for head-first burrowing. Hyperossification can probably be regarded more as a specialization to both head-first burrowing and feeding, even though an impact of miniaturization cannot be excluded. Hypertrophied adductor mandibulae muscles and the enlarged coronoid process can be associated with both feeding requirements (it enhances bite forces necessary for their predatory behavior) and with a burrowing lifestyle, as well as miniaturization.

Adaptation, Biological↗

Aeromedical implications of the X-Chrom lens for improving color vision deficiencies.

A red contact lens (X-Chrom lens) worn on the nondominant eye by 12 color-defective subjects caused significant improvements on the Dvorine, Ishihara, and Hardy-Rand-Rittler pseudo-isochromatic color plate tests. Color vision scores on the Farnsworth Lantern, Color Threshold Tester, and Aviation Signal Light Gun were not improved. Minimal changes were found on the Farnsworth D-15 test, aeronautical chart color identification task, visual acuity, phoria, and stereoscopic depth perception. Control and color-defective subjects perceived a change in the path of a pendulum (Pulfrich test) when viewing through the X-Chrom lens or a monocular red filter. The X-Chrom lens may require extended wearing before its optimum effect becomes apparent.

Adult↗

Parapapillary atrophy in the chronic open-angle glaucomas.

BACKGROUND: A study was carried out to evaluate whether parapapillary atrophy varies among different chronic open-angle glaucomas. METHODS: The study included 625 Caucasian patients with primary open-angle glaucoma (POAG), 123 patients with secondary open-angle glaucoma (pseudoexfoliative glaucoma n=86; pigmentary glaucoma n=37), and 481 normal subjects. POAG was differentiated into highly myopic POAG (n=32), juvenile POAG (n=33), focal normal-pressure glaucoma (n=46), "sclerotic POAG" with marked fundus tesselation (n=89), and "ordinary POAG" comprising the remaining POAG eyes (n=425). Color stereo optic disc photographs were morphometrically evaluated. RESULTS: The beta zone of parapapillary atrophy was significantly larger in sclerotic POAG (1.00+/-1.37 mm(2)) than in pseudoexfoliative glaucoma (0.65+/-0.93 mm(2)), pigmentary glaucoma (0.42+/-0.58 mm(2)), ordinary POAG (0.66+/-1.06 mm(2)), and focal normal-pressure glaucoma (0.34+/-0.36 mm(2)). In ordinary POAG, the beta zone was significantly larger than in juvenile POAG (0.33+/-0.72 mm(2)). Compared with all glaucoma groups, the beta zone was significantly the smallest in the normal eyes (0. 18+/-0.57 mm(2)). The alpha zone of parapapillary atrophy was significantly larger in the glaucoma groups than in the normal control group, with no significant difference between the glaucoma groups. The myopic crescent (4.11+/-3.42 mm(2)) present in the highly myopic eyes was significantly larger than the beta zone in any other group. CONCLUSION: The beta zone of parapapillary atrophy varies by a factor of more than 3 between the various types of chronic primary and secondary open-angle glaucomas. This may be important diagnostically and pathogenetically.

Adult↗

The effect of a moving distractor on the initiation of smooth-pursuit eye movements.

As a step toward understanding the mechanism by which targets are selected for smooth-pursuit eye movements, we examined the behavior of the pursuit system when monkeys were presented with two discrete moving visual targets. Two rhesus monkeys were trained to select a small moving target identified by its color in the presence of a moving distractor of another color. Smooth-pursuit eye movements were quantified in terms of the latency of the eye movement and the initial eye acceleration profile. We have previously shown that the latency of smooth pursuit, which is normally around 100 ms, can be extended to 150 ms or shortened to 85 ms depending on whether there is a distractor moving in the opposite or same direction, respectively, relative to the direction of the target. We have now measured this effect for a 360 deg range of distractor directions, and distractor speeds of 5-45 deg/s. We have also examined the effect of varying the spatial separation and temporal asynchrony between target and distractor. The results indicate that the effect of the distractor on the latency of pursuit depends on its direction of motion, and its spatial and temporal proximity to the target, but depends very little on the speed of the distractor. Furthermore, under the conditions of these experiments, the direction of the eye movement that is emitted in response to two competing moving stimuli is not a vectorial combination of the stimulus motions, but is solely determined by the direction of the target. The results are consistent with a competitive model for smooth-pursuit target selection and suggest that the competition takes place at a stage of the pursuit pathway that is between visual-motion processing and motor-response preparation.

Animals↗

[Color vision defects in chronic open angle glaucoma].

Glaucomatous optic nerve atrophy is associated with morphological and psychophysical changes. Using Roth's Besancon anomalometer, the Farnsworth 100 hue test and Nagel's anomaloscope, we examined color vision in 86 eyes of 51 patients suffering from chronic open-angle glaucoma and 57 eyes of 41 normal subjects. In the normal control group, blue und green sensitivity decreased and, accordingly, the anomaly quotient tested with Nagel's anomaloscope increased significantly (p less than 0.00001) with age. If the glaucoma and control groups were matched for age, refractive error and central visual acuity, decreasing blue sensitivity significantly (p less than 0.05) correlated with diminished visibility of the retinal nerve fiber bundles, a higher morphological glaucoma stage and larger perimetric defects. The presence and depth of localized defects of the retinal nerve fiber layer were not significantly different in glaucoma subgroups with lower and higher blue sensitivity, respectively, when the subgroups were matched for age, refractive error and visual acuity. No papillomorphologic marker for the cyanodyschromatopsia was detected. Red-green color vision was not significantly different between the normal and glaucoma eyes. Testing of blue color vision as an additional method is useful in the differential diagnosis of beginning glaucomatous optic nerve damage in patients with clear optic media and lack of macular changes.

Adult↗

Hidden visual processes.

Isoluminant stimulus is an image whose edges are defined only by a change in color, not by change in brightness. The stimulus here is imperfect: the blue parts and the green parts of the image are only as nearly equal in brightness as they can be on the printed page. Moreover, the change in brightness beyond the edge of the page is apparent, and so is the fact that the reader is holding the magazine at reading distance. When such cues are removed under laboratory conditions, subjects faced with an isoluminant stimulus prove unable to bring its edges into focus. This deficiency contributes to making a familiar face hard to recognize. The experiment indicates that the brain process underlying visual accommodation (the focusing of the eyes) cannot "see" color; it is a hidden process distinct from the processes that lead to perception. The image shows Groucho Marx as he appeared in the motion picture Horse Feathers.

Color Perception↗

Iris pigmentation and AC thresholds.

Data from 160 White children were used to analyze possible associations between iris pigmentation and AC pure-tone thresholds. Iris pigmentation was graded from iris color using glass models of eyes, and AC thresholds were obtained under carefully controlled conditions. Analyses of variance using two groupings of iris color grades showed no evidence of an association between iris color grade and AC thresholds. Furthermore, inspection of arrays of the actual glass eye models, in conjunction with the order of mean thresholds at each test frequency, did not indicate the presence of an association between iris color grades and thresholds. It was concluded that while iris pigmentation may be related to some aspects of hearing ability, it does not appear to be related to AC thresholds in children.

Adolescent↗

Interocular transfer in goldfish: color easier than pattern.

Goldfish were trained to monocularly discriminate different patterns that also differed in color. When tested with reversed combinations of color and pattern cues, the fish responded on the basis of pattern while using the trained eye but on the basis of color while using the untrained eye. Interhemispheric transfer of color information was therefore more effective than that of pattern.

Animals↗

Comparison of nonmydriatic digitized video fundus images with standard 35-mm slides to screen for and identify specific lesions of age-related macular degeneration.

PURPOSE: The purpose of this study was to compare nonmydriatic digitized images obtained using a digital imaging system (resolution of 640 x 480 pixels) with 35-mm slide images for detecting specific findings of age-related macular degeneration (AMD) and to evaluate its usefulness as a screening tool in detecting signs of AMD. METHODS: Seventeen consecutive patients (33 eyes) underwent digital color imaging (with a nonmydriatic, 45-degree, fundus camera attached to a digital back) and standard 35-mm, 30-degree retinal color photography of the fundus: posterior pole, nasal retina, and temporal retina. The images were later reviewed for the presence or absence of specific retinal findings. The images were not compressed. Primary outcome measures included the presence or absence of drusen, hard exudate, choroidal neovascularization (CNV), subretinal hemorrhage, retinal pigment epithelial (RPE) changes, subretinal fibrosis, pigment epithelial detachment (PED), and subretinal fluid. Presence of drusen, with or without any one of the other findings, and presence of disciform scar or geographic atrophy were positive indications in screening for AMD. RESULTS: Agreement between image type was highest for PED (97%), CNV (91%), and subretinal fibrosis (91%); and lowest for RPE changes (63%). Sensitivity, specificity, positive predictive value, and negative predictive values were determined using the 35 mm-slide images as the reference for comparison. Sensitivity ranged from 40% (hard exudates) to 75% (subretinal hemorrhage). Specificity ranged from 88% (drusen) to 100% (hard exudate, CNV, RPE changes, PED). Positive predictive value ranged from 67% (subretinal hemorrhage) to 100% (hard exudate, CNV, RPE changes, PED). Negative predictive value ranged from 44% (drusen) to 97% (PED). For the purposes of screening for any evidence of AMD, the system was 70% sensitive. CONCLUSION: This digital fundus imaging system with 640 x 480 pixel resolution has low sensitivity and high specificity, as compared with 35-mm slide images, for detection of early AMD, but higher sensitivity for late findings (CNV, scar, atrophy) of AMD. Because of sensitivity for detecting any AMD coupled with the low sensitivity for detecting CNV, the system is not useful for evaluating AMD patients who require close follow-up and who are at risk for more severe visual loss.

Aged↗

Our experience with Solcoseryl Eye-Gel in the treatment of corneal lesions. A randomised double-blind study (with 1 color plate).

A comparative study of Solcoseryl Eye-Gel versus a 2.4% cysteine eye-gel was carried out under controlled conditions (randomised and double-blind) on a total of 61 patients with corneal lesions (52 foreign body injuries, 9 corneal erosions). The results showed a marked superiority of Solcoseryl Eye-Gel with respect to more rapid healing and also with respect to the possible subsequent development of a corneal macula.

Actihaemyl↗

Pigmentary traits, modalities of sun reaction, history of sunburns, and melanocytic nevi as risk factors for cutaneous malignant melanoma in the Italian population: results of a collaborative case-control study.

BACKGROUND: To the authors' knowledge, limited data are available from Mediterranean populations concerning risk factors for malignant melanoma. A few Italian case-control studies have produced conflicting results regarding the association between malignant melanoma and pigmentary traits, sunburns, and melanocytic nevi. METHODS: A case-control study was conducted within the framework of the Italian Group for Epidemiologic Research in Dermatology (GISED). Twenty-seven centers in the north and south of Italy participated. A total of 542 cases and 538 controls were entered onto the study. A standardized questionnaire was administered to cases and controls. Cases and controls also were examined by trained dermatologists who were required to count the number of melanocytic nevi (those measuring > or = 2 mm and > 6 mm in greatest dimension, separately) and to make judgments regarding pigmentary traits. RESULTS: In the multivariate analysis, eye and skin color, propensity to sunburn, history of sunburns before age 15 years, and solar lentigines all were associated with malignant melanoma. In addition, the risk of melanoma increased with the number of melanocytic nevi > or = 2 mm. Nevi > 6 mm in greatest dimension had effects on risk that appeared to be independent from the effects of smaller nevi (2-6 mm). CONCLUSIONS: The results of the current study largely are similar to those obtained in northern European countries, the U.S., and Australia and provide further evidence of the importance of selected pigmentary traits, sun exposure, and the number of melanocytic nevi in the risk of cutaneous malignant melanoma.

Adult↗

The Cajuns of Southern Alabama: morphology and serology.

A survey was conducted of 324 members of the Cajun isolate of Southern Alabama. Tradition and appearance suggest that this population of about 3,000 are not entirely White, Black, or Indian but constitute a triracial community somewhat reproductively isolated and inbred. The earliest American settlement in the area, along the banks of the Mobile and Tombigbee Rivers, lay between Spaniards to the South and Indian tribes on the other sides: Creek, Choctaw, and Cherokee. Physical measurements are reported for 71 adults, plus color of skin, eyes, and hair. X-rays were taken of wrist and ankle bones of some 253 children. Red blood samples were typed on adults and children, and haptoglobin, Gm, and Gc types were determined from serum. History and physical examinations were also made. Physical measurements and observations suggest predominantly White ancestry, and D2 analysis confirms this, with least similarity to Indians. Analysis of serological traits implies almost 70% White, almost 30% Black, and very little Indians genes. Few defects of clear genetic etiology were discovered. Growth patterns judged from X-rays appeared normal. All genetic loci testable were in Hardy-Weinberg equilibrium except Gc. While history and some common surnames suggest endogamy in the past, the medical and serological findings, plus some additional surnames, indicate that the isolate has already been largely diluted or dissolved.

Adolescent↗

Risk of melanoma among radiologic technologists in the United States.

Our study examines the risk of melanoma among medical radiation workers in the U.S. Radiologic Technologists (USRT) study. We evaluated 68,588 white radiologic technologists (78.8% female), certified during 1926-1982, who responded to a baseline questionnaire (1983-1989) and were free of cancer other than nonmelanoma skin at that time. Participants were followed through completion of a second questionnaire (1994-1998). We identified 207 cases, 193 subjects who reported first primary melanoma and 14 decedents with melanoma listed as an underlying or contributory cause of death. We examined risks of occupational radiation exposures using work history information on practices, procedures, and protective measures reported on the baseline questionnaire. Based on Cox proportional hazards regression, melanoma was significantly associated with established risk factors, including constitutional characteristics (skin tone, eye and hair color), personal history of nonmelanoma skin cancer, family history of melanoma and indicators of residential sunlight exposure. Melanoma risk was increased among those who first worked before 1950 (RR = 1.8, 95% CI = 0.6-5.5), particularly among those who worked 5 or more years before 1950 (RR = 2.4; 0.7-8.7; p (trend) for years worked before 1950 = 0.03), when radiation exposures were likely highest. Risk was also modestly elevated among technologists who did not customarily use a lead apron or shield when they first began working (RR = 1.4; 0.8-2.5). Clarifying the possible role of exposure to chronic ionizing radiation in melanoma is likely to require nested case-control studies within occupational cohorts, such as this one, which will assess individual radiation doses, and detailed information about sun exposure, sunburn history and skin susceptibility characteristics.

Adult↗

Nonmelanoma skin cancer in relation to ionizing radiation exposure among U.S. radiologic technologists.

Ionizing radiation (IR) is an established cause of nonmelanoma skin cancer, but there is uncertainty about the risk associated with chronic occupational exposure to IR and how it is influenced by ultraviolet radiation (UVR) exposure. We studied 1,355 incident cases with basal cell carcinoma (BCC) and 270 with squamous cell carcinoma (SCC) of the skin in a cohort of 65,304 U.S. white radiologic technologists who responded to the baseline questionnaire survey in 1983-1989 and the follow-up survey in 1994-1998. Cox's proportional-hazards model was used to estimate relative risks of BCC and SCC associated with surrogate measures of occupational exposure to IR and residential UVR exposure during childhood and adulthood, adjusted for potential confounders including pigmentation characteristics. Relative risks of BCC, but not of SCC, were elevated among technologists who first worked during the 1950s (RR = 1.42; 95% CI = 1.12-1.80), 1940s (RR = 2.04; 95% CI = 1.44-2.88) and before 1940 (RR = 2.16; 95% CI = 1.14-4.09), when IR exposures were high, compared to those who first worked after 1960 (p for trend < 0.01). The effect of year first worked on BCC risk was not modified by UVR exposure, but was significantly stronger among individuals with lighter compared to darker eye and hair color (p = 0.013 and 0.027, respectively). This study provides some evidence that chronic occupational exposure to IR at low to moderate levels can increase the risk of BCC, and that this risk may be modified by pigmentation characteristics.

Adult↗