光学性角膜移植术后眼球屈光状态的变化

Refraction change after keratoplasty

目的探讨光学性穿透性角膜移植术后眼球屈光状态变化的规律。方法对圆锥角膜、角膜白斑、角膜营养不良采用不同直径大小角膜植片进行部分穿透性角膜移植术，术后随访2年。结果术后角膜植片透明，视力恢复但残留屈光不正者较多，矫正视力明显好于裸眼视力。术后早期散光较大，随时间延长，散光逐渐减小，角膜植片与植床趋近于正常生理状态。术后不同时间植片大的一组术后散光明显少于植片小的一组（P〈0．05）。与术前相比，术后眼轴变短，（P〈0．05）。植片与植床等大的一组眼轴缩短较植片大于植床0．25mm的一组明显（P〈0．05）。结论术后视力普遍提高，眼轴变短，散光明显。植片与植床的差值越小，眼轴缩短越明显。植片越小、散光越大。角膜植片大小的选择，植片与植床的匹配，拆线时机的选择，熟练的缝合技术，可以影响术后眼球的屈光状态，对提高光学性角膜移植术的效果具有重大意义。

Objective To explore the refraction changes after penetrating keratoplasty. Methods 65 cases （68 eyes） underwent penetrating keratoplasty with diagnoses as keratoconus, corneal leukoma or corneal dystrophy. The patients were followed up for 2 years. Results All grafts were transparent after sug- cry. The visual acuities were improved in all cases, however most patients had residual ametropia. The cor- rected visual acuities were better than the naked vision. The astigatism was bigger at the early stage after sur- gery. As time went by, the astigmatism became smaller. The graft and the plant bed had the tendency to re- cover to the normal physiological condition. The astigmatism was smaller in the group with large graft than that in the group with small graft at different time points after surgery （ P 〈 0.05 ）. The axial length became shorter after sugery compared with the preoperative values （P 〈 0.05）. The shortage of axial length was lar- ger in the group with equal size of graft and bed than the group in which the graft was bigger than the bed 0.25 mm （ P 〈 0.05）. Conclusion The patients have better vision, shorter axial length and larger astig- matism after keratoplasty. The closer of the size of the graft and bed are, the more shortening of the axial length becomes. The eyeball with smaller graft usually has larger astigmatism. Suitable size of the corneal graft, the match of the graft and bed, time of removing sutures and skill of suturing are the factors which in- fluence the refraction after keratoplasty.