[Capricious ocular accommodation and convergence].
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Accommodation, Ocular↗
Biomedical subjects
P U Koskela
Publications and source records attributed to P U Koskela.
Permanent results of pleoptic treatment.
The value of pleoptic treatment was assessed by a long-term follow-up of patients treated 15-22 years ago, employing a questionnaire sent to 232 patients and a clinical examination of a sample of 44 of these. Answers were received from 157 persons with different occupations and educational levels who were fairly representative of the population of Northern Finland as a whole. The treatment was considered beneficial by 62% of these. The primary improvement in the mean visual acuity (VA) from 0.33 to 0.86 among the 44 persons examined proved to be partly transitory, the final mean value being 0.61. The poorest results were found in the combined strabismic and anisometropic amblyopia group. The final VA correlated positively with the initial VA and negatively with age at the time of treatment. Binocular single vision improved the prognosis. Altogether 1/4 of the patients achieved a VA of 1.0 or better, about one half experienced no permanent increase in VA and the remainder were distributed evenly between these two extremes.
Adolescent↗
The effect of jogging on visual field indices.
The Humphrey 30-2 visual field was examined 9 times before and after an 8-km jog in one subject, whose contrast sensitivity had been found to improve after jogging. The mean deviation improved statistically significantly suggesting better sensitivity of the visual system after jogging. Our results suggest that in some individuals physical exercise influences the factors which lie behind the visual field long-term fluctuation.
Contrast Sensitivity↗
Jogging and contrast sensitivity.
Threshold contrast sensitivity was measured using sinusoidal gratings with the method of increasing contrast both before and after jogging in fresh air. The mean contrast sensitivity of 11 subjects was higher after jogging at all three spatial frequencies studied (1, 6 and 19 c/deg). The differences were statistically significant. The effect of jogging was subject to individual variation, some 'unstable' subjects responding strongly and some 'stable' subjects showing no change at all. Two 'unstable' subjects were tested several times, and their strong response proved to be repeatable.
Adult↗
Contrast sensitivity in amblyopia. I. Changes during CAM treatment.
Contrast sensitivity of 29 children (mean age 8 years) was measured at the beginning, at the end, and during the follow-up of CAM treatment. The deficiency in contrast sensitivity of amblyopic eyes was most notable at high spatial frequencies, but in some cases it also occurred at intermediate and low spatial frequencies. Individually no distinct association was noticed between various CSF-types and different groups of amblyopia, but on average in anisometropia the deficiency at low spatial frequencies was more pronounced than in purely strabismic cases. During treatment contrast sensitivity improved significantly, most notable at high frequencies. Correlation between visual acuity and contrast sensitivity was poor. During follow-up visual acuity deteriorated in most cases, but contrast sensitivity remained on the level where it was at the end of the treatment. Our modification of measuring contrast sensitivity was tested in two samples of normal subjects. Between 1-11 c/deg contrast sensitivity was statistically significantly better in the adults (n = 25) than in the children (n = 20).
Adolescent↗
Contrast sensitivity in amblyopia. III. Effect of occlusion.
Contrast sensitivity of 26 children (mean age 9 years) was measured using vertical gratings during the course of pleoptic treatment. A statistically highly significant improvement in the vision of amblyopic eyes occurred during intensive treatment in the hospital. Occlusion of the amblyopic eye (inverse occlusion) before the pleoptic treatment did not effect the function of the amblyopic eyes. During 8-week occlusion of the dominant eye (direct occlusion) after pleoptic treatment changes in the vision of the amblyopic eyes were statistically insignificant. In some patients there was change in contrast sensitivity without a corresponding change in visual acuity. The contrast sensitivity of the dominant eye decreased markedly during occlusion in 12 patients. After a continuous occlusion of only 2 weeks there was a statistically significant decrease at spatial frequency 6 c/deg. There was no simultaneous decrease of visual acuity; thus the change can be called 'hidden occlusion amblyopia'. An additional 8-week occlusion did not cause any statistically significant decrease in contrast sensitivity, but visual acuity of 2 patients decreased slightly, a sign of beginning occlusion amblyopia. The changes disappeared during 'Einschleich'-occlusion or penalization except in one child whose previously dominant eye became non-dominant and slightly amblyopic.
Adolescent↗
Contrast sensitivity in amblyopia. II. Changes during pleoptic treatment.
Contrast sensitivity at spatial frequencies 1-19 c/deg was measured in 56 children (mean age 10 years), who had received pleoptic treatment. Measurements were done at the beginning and at the end of a pleoptic treatment period as well as at follow-up using vertical gratings. A deficiency was observed in contrast sensitivity of amblyopic eyes at all spatial frequencies, but it was most notable at high spatial frequencies. Both types of CSF presented by Hess & Howell (1977) were found in all groups of amblyopia. A statistically significant improvement in the mean value of contrast sensitivity of the amblyopic eyes was observed at all spatial frequencies during the pleoptic treatment, although in 12 cases fixation and vision did not improve. Correlation with the improvement in visual acuity was poor. In several cases a change was observed in only one of the two parameters in question. Regarding the better eye, there were some signs of 'hidden occlusion amblyopia': in a few cases contrast sensitivity of the dominant eye deteriorated during the treatment period without a changes in visual acuity only to risk back to the previous level at the follow-up.
Adolescent↗
Contrast sensitivity in amblyopia. IV. Assessment of vision using vertical and horizontal gratings and optotypes at different contrast levels.
The contrast sensitivity of 49 amblyopic children (mean age 9 years) was measured in the beginning and at the end of a treatment period using both vertical gratings and optotypes (LH-4 contrast test) at 2, 3, 5 and 75% contrast. The contrast sensitivity of 37 patients was also measure using horizontal gratings. The contrast sensitivity of the dominant eyes measured with vertical gratings was generally higher than when measured with horizontal gratings. The difference was statistically significant at spatial frequencies 1 and 6 c/deg. A similar difference was present in the amblyopic eyes only at the spatial frequency 1 c/deg both before and after the treatment. Individual variation was great; in a given patient the relationship between the two measurements varied from one spatial frequency to the next. It has been shown in earlier investigations that contrast sensitivity measurements using gratings reveal important new information in the study of amblyopia. Both tests, used in this investigation, measure visual function in the low contrast domain and improve follow-up of the changes in vision during treatment of amblyopia when used in addition to visual acuity measurements. Low contrast optotype test seems to measure contrast sensitivity in amblyopia closely similarly to the grating test. The slight difference in detecting a 'hidden occlusion amblyopia' at the intermediate spatial frequencies needs further study.
Adolescent↗