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J Gwiazda

Publications and source records attributed to J Gwiazda.

12 recordsLinked to original sources
PubMed1989

From visual acuity to hyperacuity: a 10-year update.

Visual acuity, the most basic measure of developing pattern vision in human infants, has been used extensively for detecting anomalies of vision and oculomotor coordination. In the past 10 years much has been learned about the development of two hyperacuities, namely, vernier acuity and stereoacuity. These two acuities become superior to grating acuity after the third month and remain so throughout life. Compared to females, males show slower development of stereopsis and vernier acuity, but not grating acuity, during the third through sixth months. We have suggested that this may result from the neurotrophic effects of the early pulse of testosterone found in males. Measures of vernier acuity have proven effective in detecting meridional amblyopia in older children who had significant astigmatism in the first year and subsequently lost it. The susceptible period for acquiring meridional amblyopia extends from the second half of the first year to at least the end of the second year. Deviations from the typical oblique effect (equal acuity for vertical and horizontal edges; equal, but lower, acuity for left oblique and right oblique) may result from uncorrected astigmatism early in life.

Amblyopia↗
PubMed1986

Congenital myopic esotropia: a case study.

A congenital myope developed a 20 delta left esotropia at 8 months of age. His eyes aligned immediately with a -4.00 D correction and would become esotropic when the glasses were removed. Before eyeglass wear best corrected acuity was reduced for both eyes with the left eye acuity significantly lower than the right. From age 8 to 12 months with part-time eyeglass wear, acuity improved and became equal for the two eyes. At 12 months of age the eyeglasses were lost and within 1 month the strabismus no longer responded to minus lenses and amblyopia reappeared in the left eye. This indicates that a myopic infant may stop bifixating blurred images beyond his far point and then cease to be able to relax convergence thereafter. It has the broader implication that tonic vergence posture and AC/A ratio may develop according to the visual experience of each infant.

Esotropia↗
PubMed1985

Infant astigmatism and meridional amblyopia.

The orientation preferences of 70 infants aged 7 to 53 weeks with significant astigmatism [1.0 or more diopters (D)] were measured using a preferential looking procedure with paired gratings. The preference data show the consequences of the blurring effects of astigmatism when these are not compensatable by accommodation. Data from infant astigmats tested with optical correction look like those of nonastigmats. We have found no evidence for the development of meridional amblyopia during the first year of life.

Accommodation, Ocular↗
PubMed1985

The development of visual acuity in infant astigmats.

Acuity for vertical, horizontal, and oblique gratings was measured in 77 infant astigmats using a preferential looking procedure. Measurements were made with the refractive error uncorrected. Most of the infant astigmats were slightly to moderately hyperopic with respect to the test distance of 50 cm. Their acuity was not significantly different from that of a group of non-astigmatic infants. Average acuity for vertical and horizontal gratings increased from 6/200 at 1 month of age to 6/24 at 1 yr. Average acuity for oblique gratings increased more slowly, so that by 1 yr of age it was only 6/33. The only infants to show reductions in acuity were those with a strong myopic focus and one infant with a very strong hyperopic focus. When this infant was tested with optical correction, acuity improved to normal levels. This suggests that meridional amblyopia develops sometime after the first year of life or that it is confined to high spatial frequencies.

Astigmatism↗
PubMed1978

Astigmatism in infants.

Compared with children of school age, infants show ten times the incidence and considerably greater amounts of clinically significant astigmatism. The amount begins to decrease in the second semester of life, and the incidence declines during the third year. The unanticipated results bear on both the etiology and the neural sequelae of astigmatism.

Age Factors↗
PubMedDate not supplied

Binocular function in human infants: correlation of stereoptic and fusion-rivalry discriminations.

Studies of stereopsis in infants have shown that the average age of onset is 3.5 months. This is the same age at which infants first show evidence of another binocular function, namely, preference for binocularly fusible patterns over rivalrous ones. We tracked the development, using two-alternative forced-choice preferential looking, of the two forms of binocular function in 17 infants, 11 male and six female. They were tested at regular intervals until they showed preferences for 1) a fusible pattern (vertical stripes presented to each eye) over a rivalrous one (vertical stripes presented to one eye, horizontal stripes to the other), and 2) a line stereogram of 32 min crossed disparity over a comparable stereogram with zero disparity. The correlation between the age of onset of the fusion preference (mean 12.4 weeks) and the age of onset of stereopsis (mean 11.0 weeks) was r = 0.79. Female infants showed a preference for the fusible stimulus at a mean age of 9.9 weeks, significantly earlier than the males at a mean age of 13.8 weeks. Similarly, females also showed evidence of stereopsis at an earlier age (9.1 weeks compared with 12.1 weeks for males).

Age Factors↗