改良深板层角膜移植治疗圆锥角膜屈光状态的改变及相关因素

背景:传统深板层角膜移植治疗圆锥角膜后弹力层穿孔率较高.目的:观察改良深板层角膜移植治疗圆锥角膜后屈光状态的长期改变及相关因素分析.方法:采用改良深板层角膜移植法治疗46例(51眼)圆锥角膜患者,记录移植前后裸眼视力和最佳矫正视力;移植前按平均角膜曲率大小分为两组,平均角膜曲率≥60 m-1组与<60 m-1组,观察移植后24个月的等效球镜、散光、角膜曲率,并分析眼轴与术后屈光状态的相关性.结果与结论:与移植前比较,移植后1,6,12,18,24个月的裸眼视力及最佳矫正视力均有显著提高(P < 0.01或P < 0.05),移植后6个月内视力是显著提高的,6~18个月视力虽有一定的提高,但基本是处于稳定的趋势,18~24个月视力显著提高,显示随着移植后时间的延长,视力逐渐提高并趋于稳定,说明改良深板层角膜移植后长期疗效佳.两组移植后的等效球镜、移植后散光、平均角膜曲率均较移植前明显改善,但两组间差异均无显著性意义(P > 0.05),眼轴与移植后的等效球镜、裸眼视力、角膜散光有一定的负相关性.说明改良深板层角膜移植后等效球镜向近视方向移动,角膜散光逐渐减小,平均角膜曲率逐渐增大.移植前角膜曲率差异对改良深板层角膜移植后屈光状态无明显影响.眼轴与术后屈光状态有一定的相关性.

Refraction change and influential factors of keratoconus after modified deep lamellar keratoplasty

BACKGROUND:Traditional deep lamellar keratoplasty in keratoconus treatment shows a high perforation of Descemet’s membrane.OBJECTIVE:To study the long-term results of modified deep lamellar keratoplasty(DLKP) for the treatment of keratoconus,and analyze related factors.METHODS:A total of 46 patients(51 eyes) with keratoconus received modified DLKP.The uncorrected visual acuity and best corrected visual acuity were recorded before and after surgery;according to preoperative mean corneal curvature,all patients were divided into two groups,one group is ≥ 60 m-1(38 eyes) and the other group is < 60 m-1(13 eyes).Spherical equivalent,astigmatism and mean corneal curvature were recorded between the two groups within 2 years postoperatively,and the correlation between postoperative refractive state and eye axis was analyzed.RESULTS AND CONCLUSION:The uncorrected visual acuity and best corrected visual acuity at postoperative 1,6,12,18,24 months were significantly improved compared with before surgery(P < 0.01 or 0.05).The visual acuity was improved significantly within 6 months after the surgery,then maintained stable and improved slightly from 6 months to 18 months after the surgery,and improved significantly from 18 months to 24 months after the surgery.These results showed that the visual acuity improved and trended to be stable with the extension of postoperative time,which indicated that the long-term results of modified DLKP for the treatment of keratoconus was much better.The spherical equivalent,astigmatism and mean corneal curvature of the two groups were all improved within 2 years postoperatively,but there was no statistical difference between the two groups(P > 0.05).There was a negative correlation between eye axis and the spherical equivalent,astigmatism,mean corneal curvature within 24 months after the surgery(r=-0.30,r=-0.29,r=-0.61).The spherical equivalent and mean corneal curvature increased gradually while the corneal astigmatism decreased gradually after DLKP,there was no obvious influence of the mean corneal curvature on the refractive state after DLKP,while eye axis was related.