| Autor: |
Rainey BB; Indiana University School of Optometry, 800 E Atwater Avenue, Bloomington, Indiana, 47405, United States., Goss DA, Kidwell M, Feng B |
| Jazyk: |
angličtina |
| Zdroj: |
Clinical & experimental optometry [Clin Exp Optom] 1998 Sep-Oct; Vol. 81 (5), pp. 185-192. |
| DOI: |
10.1111/j.1444-0938.1998.tb06733.x |
| Abstrakt: |
BACKGROUND: Clinicians frequently assess the accommodative convergence to accommodation (AC/A) ratio using near phoria measurements and accommodative stimuli. The purpose of this study was to evaluate the repeatability of AC/A ratio measurements and to compare the response AC/A ratio to stimulus AC/A ratios determined two different ways. METHODS: Heterophorias and accommodative responses to different stimuli were measured simultaneously on eight subjects at two visits. A Canon Auto Ref R-1 autorefractor was used to measure accommodative response, while vergence posture was measured using the modified Thorington heterophoria technique. These results were used to calculate response-slope, stimulus-slope and stimulus-gradient AC/A ratios and the means of these ratios for each session were compared. Correlations between the response AC/A ratios and the stimulus AC/A ratios were calculated. RESULTS: The mean response AC/A ratios for the two sessions were 3.8 prism dioptres per dioptre for each session. The correlation between the slope-determined ratios was 0.56, and between the response-slope and the stimulus-gradient AC/A ratios the correlation was -0.03. The regression equation for the slope-determined AC/A ratios was calculated. CONCLUSIONS: Means for the two sessions were not significantly different for any of the AC/A ratios. The response-slope and stimulus-slope AC/A ratios had a moderately significant correlation and a predictive regression equation was determined. The stimulus-gradient AC/A ratios were not correlated with the response-slope AC/A ratios. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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