|
|
|
|
|
|
| Factors Influencing Postoperative Asphericity after LASIK for Myopia |
|
| 作者：Paul CS.… 文章来源：From The Buddhist Tzu Chi General Hospital, Taipei , Taiwan1; University of Illinois,Chicago, Illinois, USA 2; and Harvard Medical School, Boston, Massachusetts, USA3. 点击数3890 更新时间：2006/7/10 20:25:53 文章录入：毛进 责任编辑：毛进 |
|
|
|
| Purpose: To determine whether preoperative corneal asphericity has an effect on postoperative asphericity after myopic laser in situ keratomileusis (LASIK). Setting: University-based refractive surgery center, Boston, Massachusetts, USA.
Methods: Patients who had EyeSys topography scans before and after myopic LASIK were included and subjected to chart review. One hundred and twenty-one eyes of 38 men and 28 women, mean age at the time of surgery 40 + 8.78 (range 22-57) years, were included in the study. The Holladay Diagnostic Summary was used to estimate corneal asphericity (Q). Patients were divided into 3 groups based on the distribution of preoperative Q values (Qo). Group 1 included all patients with a Qo less than –0.22, Group 2 includes Qo from –0.22 to 0, and Group 3 included positive Qo. Statistical analysis: Linear regression and one-way ANOVA with Tukey multiple comparisons were used to analyze the data at 0.05 significance level (SPSS version 10.0). Results: There is a tendency of oblate shift and plateau effect after 5 months postoperatively. The correlation of positive change of dQ per increasing amount of treatment is statistically significant (R2=0.897, p-value=0.015). The preoperative asphericity (Qo) differs from postoperative Q at T1 (p-value = 0.044), at T2 (p-value = 0.001), and at T3 (p-value< 0.0001). The preoperative asphericities are significantly different from those postoperative ones (p-value < 0.0001). The effect of change in postoperative asphericity compared to preoperative asphericity (slope) increases over time, and shows a statistically significant correlation (R2=0.807, p-value=0.031). There is a tendency toward oblateness (dQ>+0.05) postoperatively over time. Regardless of prolateness, all corneas illustrate a tendency toward oblateness with increasing magnitude of treatment over time.
Conclusions: The preoperative corneal prolateness shows an effect on the postoperative asphericity at the early stage after myopic LASIK; however, all corneas, regardless of prolateness, have a tendency toward oblateness with increasing magnitude of treatment over time.
|
|
|
|
|
|
|
|
|
|
