| Sub-title | |
| Author | M Francalanza |
| Abstract | Purpose: The aim of this study was to consider changes in the level of stereo acuity with different levels of corrected and uncorrected hypermetropia and myopia. Method: The study was a prospective study with a cross-sectional design. 55 candidates were selected from a database of ametropic subjects. 42 subjects accepted the invitation; 5 were eliminated, 18 were hypermetropic, while 19 were myopic. The level of stereo acuity was measured with and without correction, using the Frisby Plates mounted on a specifically designed bench. Results: Using regression analysis, in both the hypermetropic and myopic groups, the threshold of stereo acuity was not significantly influenced by the degree of refractive error when measured with the appropriate correction (Hypermetropic group: p>0.05; Myopic group: p>0.05). However when the threshold of the level of stereo acuity was measured in the same subjects without the appropriate correction, then these levels were significantly reduced (Hypermetropic group: p<0.001; Myopic group: p<0.0001). The mean threshold levels of stereo acuity in the hypermetropic group and the myopic group measured 33.5 and 22.5 seconds of arc respectively when measured with correction. Without the correction the mean threshold was significantly reduced to 76.4 and 75 seconds of arc respectively. Using Paired Sample t-test to compare means, it was found that the difference in means with and without correction was highly significant (Hypermetropic group: p<0.05 and Myopic group: p<0.05) Conclusions: In this study corrected ametropic subjects had a normal threshold level of stereo acuity. All subjects when uncorrected had significantly reduced stereo acuity. Finally subjects with myopia had a better threshold level of stereo acuity than those with hypermetropia. |
Published in: | |
| Journal | Malta Medical Journal |
| Volume | 18 Supplement |
| Page | |
| Date | 01/12/2006 |
| Link to journal | |
| Key words | hypermetropia, myopia, refractive error correction, stereo acuity |