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Biomedical subjects

D A Goss

Publications and source records attributed to D A Goss.

At least 55 records · Page 3Linked to original sources
PubMed1989

Meridional analysis of with-the-rule astigmatism in Oklahoma Indians.

Refraction and keratometry records were obtained for 142 consecutive with-the-rule astigmats and for 100 consecutive nonastigmats from W. W. Hastings Indian Health Service Hospital in Tahlequah, Oklahoma. Patients were 5 to 40 years of age. Patients with higher degrees of Indian ancestry were more common in the astigmatic group than in the spherical refraction group. An analysis of refractive error and keratometry by principal meridian was performed. The horizontal meridian refractive error in astigmats was most often near emmetropia. Compound myopic astigmatism and mixed astigmatism accounted for over 3/4 of the cases. The astigmats as a group had flatter corneas in the horizontal and steeper corneas in the vertical than the nonastigmats. Horizontal refractive errors and horizontal keratometry readings showed a weak but significant correlation in astigmats but not in nonastigmats.

Adolescent↗
PubMed1988

Simplified system of Purkinje image photography for phakometry.

Phakometry is a technique for measurement of the crystalline lens radii of curvature, usually involving photography of the Purkinje images. We have devised a system of comparison phakometry using commercially available camera equipment. This paper contains a description of the apparatus, technique, and necessary calculations. Reliability of the method is discussed.

Equipment Design↗
PubMed1988

Selected review on genetic factors in myopia.

This article reviews representative literature concerning pedigrees for myopia, heritability studies on refractive error and the ocular components, and other work relating to genetic factors in myopia development. Low myopia most likely reflects the influences of multiple genes. Some types of high myopia may have monogenic inheritance. Refractive error and the ocular refractive components have heritabilities intermediate between zero and one, as complied from several studies, indicating familial resemblance, but also non-genetic variation. It is likely that both heredity and environment have roles in determining refractive status. An understanding of their respective roles awaits the elucidation of the cellular and anatomical mechanisms of myopia development.

Humans↗
PubMed1988

Comparisons of commercially available devices for the measurement of fixation disparity and associated phorias.

Associated phorias were measured on 89 subjects using various commercially available devices to compare the results obtained with them. An additional 14 persons served as subjects to compare fixation disparity curve parameters obtained with two different targets. Distance associated phorias using the Mallett unit and the American Optical vectographic slide were not significantly different. Nearpoint associated phorias using the Bernell unit and the Borish card were not significantly different. Associated phorias obtained with the Bernell unit and the Borish card were lower in magnitude than the associated phorias (x-intercepts) from fixation disparity curves derived using the Sheedy disparometer. Fixation disparity curve parameters using the Wesson fixation disparity card differ from those obtained with the Sheedy disparometer. Subjective comments on the clinical use of each of these instruments are included.

Adult↗
PubMed1987

Meridional corneal components of myopia progression in young adults and children.

Records were selected from a data pool of myopic private practice patients to study the relation of refractive error change and keratometer power change in young adulthood. Selection was on the basis of three or more refractions and keratometer readings at and/or after 18 years of age. There were significant correlations between rate of myopia progression and rate of keratometer power change. Linear regression slopes of rate of refractive error change on rate of keratometer power change were in the neighborhood of 0.7. These findings were in contrast to the lack of correlation between myopia increase and corneal steepening in childhood myopia progression. Young adulthood myopia progression also appeared to be accompanied by a slight tendency toward a with-the-rule astigmatic shift.

Adolescent↗
PubMed1987

Linearity of refractive change with age in childhood myopia progression.

Refractive records of young myopic patients were collected from six optometry practices. Statistical tests for linearity (F-test and statistical significance of the correlation coefficient) were applied to the myopic measurements made between 6 and 15 years of age. In 90 to 94% of these patients, refractive changes with time were linear. Refractive changes are greater when a patient is myopic rather than hyperopic or emmetropic.

Adolescent↗
PubMed1986

Effect of bifocal lenses on the rate of childhood myopia progression.

Longitudinal records obtained from three optometry practices in the central United States were used to assess the effect of bifocal lenses on the rate of childhood myopia progression. Rates in D/year were derived by linear regression for age spans between 6 and 15 years of age. Records were available for 52 persons who wore single vision lenses (SV group) during this entire age span, and 60 persons who wore bifocal lenses (BF group) during the complete period of observation. The mean rates of myopia progression were -0.44 D/year for the SV group, and -0.37 D/year for the BF group (difference not statistically significant). When rates were determined as a function of nearpoint phoria and near binocular cross cylinder net, the BF group had rates of myopia increase which were lower in magnitude than the SV group in children with nearpoint esophoria and of higher cross cylinder net.

Adolescent↗
PubMed1985

Prevalence and pattern of adult myopia progression in a general optometric practice population.

Longitudinal data on 559 myopic patients were collected from five optometry practices; adequate adulthood refractive data for analysis (three or more visits after 18 years of age) were available for 108 patients. Patterns of refractive change were evaluated subjectively and by linear regression analysis. Most myopes do not progress in young adulthood (about 20 to 25 years of age). Myopia progression during this age period is more common among males than among females. Adulthood myopia progression is related to an increase in corneal power.

Adolescent↗
PubMed1985

Trends in the change of clinical refractive error in myopes.

Longitudinal records of 559 myopes were obtained from five optometric practices. A linear regression model was used to describe various parameters of myopia progression, including onset age, rates, and cessation age of childhood progression. Typical rates of childhood myopia increases are around 0.4 D/yr, although there is considerable individual variability. An earlier onset is correlated with the development of a higher final amount of myopia. The earlier cessation age of childhood myopia progression in females than in males is hypothesized to be related to growth factors.

Adolescent↗
PubMed1984

Overcorrection as a means of slowing myopic progression.

Thirty-six subjects (18 males and 18 females) ranging in ages from 7.38 to 15.82 years received an overcorrection of 0.75 D over the power required to correct their myopia exactly. These 36 experimental subjects were matched by control subjects selected at random from the files of the Indiana University Optometry Clinics. The criteria used in matching were sex, beginning age, beginning refractive error, and duration of time covered by the record. The mean rate of change of refractive error for the experimental group was (minus indicating increase of myopia) -0.49 D/year (range, +0.37 to -1.95 D/year) on retinoscopy and -0.52 D/year (range, +0.21 to -1.32 D/year) on subjective refraction. The mean rate of change for the control group was -0.47 D/year (range, +0.06 to -2.03 D/year) on retinoscopy and -0.47 D/year (range, +0.28 to -1.72 D/year) on subjective refraction. Rates for the experimental and control groups were not significantly different. The results of this study do not support the hypothesis that an overcorrected myope has a lower rate of increase of myopia than a myope wearing a conventional spectacle correction.

Adolescent↗
PubMed1983

Myopia development in nonhuman primates--a literature review.

This paper is a review of and commentary on the available literature dealing with myopia production in various types of monkeys and in tree shrews by experimental manipulations of their physical, visual, and/or bodily environments. The results from these studies are compared with hypotheses and models which purport to explain myopia development. Possible relations are also noted between conditions, created experimentally in myopic eyes of primates, and similar pathological states, clinically observed in certain human myopes.

Animals↗
PubMed1983

Progression of myopia in youth: age of cessation.

Patient records of young myopes were collected from three optometry practices. An index of the age at which increases of myopia in young people cease was derived using four different graphical and statistical methods. The results suggest that myopia stops increasing earlier in females than in males. There is, however, a great deal of individual variability in cessation age. Some implications for clinical practice and clinical research are discussed.

Adolescent↗
PubMed1979

Prevalence of monocular amblyopia among anisometropes.

Some 167 subjects showing anisometropia of at least 2 D, were selected from the records of the eye clinic of the Ramathibodi hospital in Bangkok, Thailand and 472 subjects showing anisometropia of at least 1 D were selected from the clinic records of the Indiana University, School of Optometry. The incidence of amblyopia (20/30 or less) was found to be 100% among least meridional hyperopic anisometropes of 3.5 D and greater, and among myopic anisometropes of 6.5 D and greater. Lower levels of anisometropia showed a smaller proportion of amblyopia. Comparable results were obtained for anisometropes computed in terms of mean spherical refractive error. Significant difference was not apparent for the Thai and American groups.

Adolescent↗