CAJ | 학술논문

角膜的非球面形态是指正常人眼角膜多为非球面的扁椭圆形,这种形态有助于提高视觉质量.不同的人眼角膜非球面系数Q值并不相同,多数为负值,各文献报道的角膜Q值正常值差异较大,角膜Q值受多种因素影响,不同象限对Q值影响较大,年龄对其影响较小,近视度数、眼轴长度、曲率半径、球差等与Q值均有一定的相关性.角膜屈光手术是矫正屈光不正的重要途径之一,但其对角膜非球面性的影响可导致眩光、视觉质量下降等问题,不同手术方式对其影响不同.波前像差引导的准分子激光原位角膜磨镶术(LASIK)、Q值引导的LASIK对Q值的影响均较标准LASIK小,而飞秒激光角膜基质透镜取出术(FLEx)对Q值的影响又较波前像差引导的LASIK小,近年开展较多的飞秒激光制瓣准分子激光原位角膜磨镶术(FS-LASIK)、微小切口基质透镜取出术(SM ILE)对角膜非球面性的影响则鲜有报道.另外,近视角膜屈光手术后Q值向正值变化,而远视手术后则向负值变化,Q值的变化量与等效球镜度呈高度正相关,激光、愈合反应等对角膜非球面性的影响尚需进一步探索.对角膜非球面性及角膜屈光手术的研究有助于获得更好的术后视觉质量,就角膜的非球面形态及不同角膜屈光手术方式对其的影响进行综述.
각막적비구면형태시지정상인안각막다위비구면적편타원형,저충형태유조우제고시각질량.불동적인안각막비구면계수Q치병불상동,다수위부치,각문헌보도적각막Q치정상치차이교대,각막Q치수다충인소영향,불동상한대Q치영향교대,년령대기영향교소,근시도수、안축장도、곡솔반경、구차등여Q치균유일정적상관성.각막굴광수술시교정굴광불정적중요도경지일,단기대각막비구면성적영향가도치현광、시각질량하강등문제,불동수술방식대기영향불동.파전상차인도적준분자격광원위각막마양술(LASIK)、Q치인도적LASIK대Q치적영향균교표준LASIK소,이비초격광각막기질투경취출술(FLEx)대Q치적영향우교파전상차인도적LASIK소,근년개전교다적비초격광제판준분자격광원위각막마양술(FS-LASIK)、미소절구기질투경취출술(SM ILE)대각막비구면성적영향칙선유보도.령외,근시각막굴광수술후Q치향정치변화,이원시수술후칙향부치변화,Q치적변화량여등효구경도정고도정상관,격광、유합반응등대각막비구면성적영향상수진일보탐색.대각막비구면성급각막굴광수술적연구유조우획득경호적술후시각질량,취각막적비구면형태급불동각막굴광수술방식대기적영향진행종술.
The corneal asphericity refers to most normal corneal surface is an aspherical flat oval,which is helpful to improve the visual quality.In most cases,corneal aspherical coefficient Q-value is negative,and different normal Q-value is reported in literatures,corneal Q-value is influenced by many factors,quadrants have great effects on it,the influence of age is weak,there are correlation between myopic degree,ocular axial length,radius of curvature,intraocular pressure and Q-value.The corneal refractive surgery is one of the most important methods to correct refractive errors,but it has negative effects on the corneal asphericity,and then results in glare,visual quality degradation and other issues.Different corneal refractive surgeries would have different effects on the corneal asphericity.Wavefront aberration-guided femtosecond laser in situ keratomileusis(LASIK) surgery and Q-value guide LASIK are superior to standardized LASIK,the change of Q-value after femtosecond lenticule extraction (FLEx) surgery is less than that after wavefront aberration guided LASIK.The influence of femtosecond laser in situ keratomileusis (FS-LASIK) and small incision lenticule extraction (SMILE) on Q-value are rarely reported.In addition,the Q-value changes from negative to positive after corneal refractive surgery of myopia,the variation tendency is opposite after hyperopia surgery.Q-value variation is highly correlated to spherical equivalent,the impact of laser and healing still needs further exploration.In order to further exploring of the corneal asphericity and getting a better effect of surgery,here is a review about normal corneal asphericity and the effects of the corneal refractive surgery on it.