夜戴和日戴Ortho-K CL对眼部的影响

目的　观察过夜配戴和日间配戴Ortho-KCL后对眼部的影响。方法　55名配戴新型Ortho-KCL(Nu-vision,HDS材料)近视患者中,过夜戴镜(OW)74只眼(近视＜5.25D,散光＜1.25D,Ⅰ组),日间戴镜(DW)36只眼(近视＞5.00D,散光＜1.75D,Ⅱ组)。观察戴镜前及戴镜后1个月、2个月、3个月及6个月的角膜中心厚度及周边部厚度的变化;A超测定眼轴长、前房深、晶体厚及玻璃体腔长度的变化;角膜内皮细胞的改变,非接触眼压测定值的变化以及有无角结膜的其它合并症。结果　角膜中心厚度均减薄,周边部均增厚,2个月时变化最显著,之后有所恢复。Ⅰ组周边部厚度变化比较显著。Ⅱ组变化值约为Ⅰ组的1/2。Ⅱ组眼轴长度及玻璃体腔长度明显大于Ⅰ组,两组戴镜后两长度有轻度缩短。Ⅰ组戴镜6个月后角膜内皮细胞密度显著降低,平均细胞面积及CV值显著增大,六角形细胞比率显著降低,Ⅱ组仅CV值增大。非接触眼压测定值两组戴镜后均较前降低,Ⅰ组有显著性改变,3个月后达最低值,然后逐渐回升,6个月后,接近戴镜前眼压值。戴镜期间,无角膜新生血管,角膜浸润,角膜感染等严重合并症出现。结论　Ortho-KCL的日间戴镜方式比过夜戴镜方式对眼的影响小,安全性相对较高。需长期利用Ortho-KCL控制和治疗近视的青少年患者应考虑适时调整戴镜方式与时间并及时更换镜片,以保证治疗的有效性和安全性。

Effects of overnight wearand daily wear Ortho-K contact lens on the eyes.

Objective To investigate the effects of overnight wear and daily wear Ortho-K contact lens on the eyes. Methods 55 myopia patients were fitted Nu-vision (HDS) Ortho-K contact lenses, 74 eyes with overnight wear (myopia＜5.25D, astigmatism＜1.25D) as group Ⅰ, 36 eyes with daily wear (myopia＞5.00D, astigmatism＜1.75D) as group Ⅱ. Non-contact tonometry, non-contact specular microscopy and A-scan ultrasonic bio & pachymetry were conducted prior to contact lens fitting and then at 1 month, 2 months, 3 months and 6 months post-fiting. Results Central corneal thickness became thinner, while peripheral corneal thickness had increased. The maximum changes were showed after 2 months Orhto-K contct lens wearing and then showed regression. There was significant changes of peripheral cornea in the group Ⅰ, and its variatons were approximately two times of group Ⅱ. Axial length in group Ⅱ was significant longer than this in group Ⅰ. They all showed little shorter after Ortho-K fitted. Endothelial cell density and percentage of hexagon decreased, average cell size and CV values increased significantly were found after 6 months Ortho-K contact lens fitted in group Ⅰ, but there was only CV values changed in group Ⅱ. Compared the prior Ortho-K contact lens wearing, non-contact IOP values of both group showed lower after the contact lens fitted. There was a significant change in group Ⅰ, up to the lowest at 3month, and then arise, it was approximately to normal value at 6 months. There were no corneal new vascularization, infiltration and infection during the contact lens wearing period. Conclusions The results indicated that daily wear Ortho-K contact lens may be less effective and more safe on the eyes. Considered the safety, young patients who using Ortho-K contact lens control the myopia progress with long-term wear, must adjust the wearing method and timetable, replace the contact lens at the proper time.