CXL治疗圆锥角膜的中期效果及术后RGPCL配适参数变化的研究

The mid-term effect of corneal collagen cross-linking for progressive keratoconus and the changes in rigid gas permeable contact lens fitting parameters

目的:探讨圆锥角膜患眼行角膜胶原交联术(CXL)后1年的治疗效果及术后硬性透气性角膜接触镜(RGPCL)适配参数的改变。方法:前瞻性队列研究。纳入自2018年5至12月于山东第一医科大学附属青岛眼科医院门诊接受快速CXL的进展期圆锥角膜患者41例(53只眼),其中男性31例,女性10例,年龄(20.46±4.15)岁。根据角膜最薄点厚度是否≥450 μm分为去上皮组(33只眼)和经上皮组(20只眼),分别采用去上皮术式和经上皮术式行CXL。术前及术后6周适配RGPCL并追踪配适情况至术后12个月。所有患眼术前和术后6周检查最佳矫正视力和角膜最薄点厚度,术前、术后6周和3、6、12个月进行角膜地形图检查获取平坦角膜曲率(Kf)、陡峭角膜曲率(Ks)及最大角膜曲率(Kmax)。采用 t检验对数据进行统计学分析。 结果:术后6周时两组框架镜矫正视力、屈光度数及角膜最薄点厚度较术前无改变,但Kf、Ks及Kmax均增加( P均<0.05);至术后3个月两组Kmax呈现下降趋势,其中去上皮术组术前及术后3、6、12个月的Kmax分别为(55.46±6.02)、(55.17±5.83)、(55.14±6.15)、(54.57±6.08)D,其中术后12个月下降显著,为(0.89±1.45)D( t=2.25, P=0.001);经上皮组术前及术后3、6、12个月的Kmax分别为(59.43±8.98)、(57.97±8.79)、(58.19±8.37)、(56.94±7.19)D,术后3、6及12个月均下降显著,且降幅更大,分别为(1.46±2.09)、(1.25±1.82)、(2.49±3.64)D( t=3.12,3.06,3.50;P=0.006,0.006,0.007)。术后两组RGPCL矫正视力、屈光度数及直径均无改变,但RGPCL基弧均减小,去上皮组减小0.07 mm而经上皮组减小0.13 mm( P均<0.05);另外,去上皮组术后抬边翘设计10只眼,较术前8只眼增加,而经上皮组术前(7只眼)较术后(4只眼)减少。环曲面边翘设计眼两组均较术前增多,去上皮组术前为2只眼,术后增加至3只眼,经上皮组术前为1只眼,术后增加至4只眼。两组术后6及12个月时RGPCL配适可接受率均较术后6周增加。 结论:圆锥角膜患眼行CXL术后6周,角膜略变凸后逐渐恢复并变平,经上皮术式效果更好;术后6周配适RGPCL的基弧较术前变陡,边翘环曲面设计需求增加,但抬边翘设计两种术式变化不同;RGPCL于术后1年仍可良好配适。

Objective To investigate the effect of corneal collagen cross-linking(CXL)for progressive keratoconus and to evaluate changes in the parameters of rigid gas permeable contact lens(RGPCL)fitting after surgery.Methods It was a prospective cohort study.Fifty-three eyes of 41 keratoconus patients received accelerated CXL in Qingdao Eye Hospital of Shandong First Medical University from May to December 2018.There were 31 males and 10 females,aged(20.46±4.15)years.According to the corneal thickness,de-epithelial CXL(33 eyes)or trans-epithelial CXL(20 eyes)was performed.The best spectacle-corrected visual acuity,refractive power and the thinnest corneal thickness at baseline and at 6 weeks were compared.Corneal topography was performed at baseline and at 6 weeks,3,6 and 12 months postoperatively.Rose K RGPCLs were used before and 6 weeks after surgery,and the fitting status was monitored until 12 months after surgery.The t test was performed to analyze the difference before and after the operation.Results The best spectacle-corrected visual acuity,refractive power,and the thinnest corneal thickness were not significantly changed over 6 weeks of follow-up,but the Kf,Ks and Kmax values were significantly increased in all patients(all P<0.05).In the de-epithelial group,the Kmax values before the operation,at 3,6 and 12 months after the operation were(55.00±5.51)diopters(D),(54.73±5.34)D,(54.58±6.15)D and(54.20±5.49)D,respectively,and the decrease at 12 months was significant[(0.80±2.05)D;t=2.25,P=0.001].In the trans-epithelial group,the Kmax values were(59.43±8.98)D,(57.97±8.79)D,(58.19±8.37)D and(56.94±7.19)D at the four time points,respectively,and the decreases at 3,6 and 12 months were all significant[(1.46±2.09)D,(1.25±1.82)D,(2.49±3.64)D;t=3.12,3.06,3.50;P=0.006,0.006,0.007].The best RGPCL-corrected visual acuity,the diameter and the average diopters of RGPCLs showed no significant change in both groups.The RGPCL base curve decreased by 0.07 mm in the de-epithelial group and by 0.13 mm in the trans-epithelial group(both P<0.05).The design of edge lifting was used in 10 eyes postoperatively in the de-epithelial group compared with 8 eyes preoperatively,and in 4 eyes postopratively in the trans-epithelial group compared with 7 eyes preoperatively.The number of eyes using the toric peripheral design of the lens was increased to 3 compared with 2 preoperatively in the de-epithelial group and from 1 to 4 in the trans-epithelial group.The acceptance rate of RGPCL fitting in both groups increased at 6 and 12 months after surgery compared to 6 weeks after surgery.Conclusions The corneal curvature became steep slightly at 6 weeks after CXL and gradually recovered and flattened.The Kmax in the trans-epithelial group decreased earlier and more than that in the de-epithelial group.The base curve of the RGPCLs was slightly reduced after 6 weeks,and the toric peripheral design was increasingly needed,but the requirement for the design of the lifted edge was different between the two groups.A good RGPCL fitting can be achieved within 1 year after CXL.