Impact Of Dry Eye Symptoms On Vision Quality Of Life After Femto-second LASIK

Objective To analyze visual quality changes and ocular surface status after femtosecond LASIK by a double-pass system(optical quality analysis system II,OQAS II system)and the Oculus? Keratograph 5M,and to observe the impact of dry eye symptoms on vision quality of life after femtosecond LASIK.Methods Sixty eyes of thirty patients with myopia were selected randomly to participate this study in the Tianjin Medical University Eye Hospital from June 2017 to December 2017.Patients were performed femtosecond laser LASIK by the same operator,including 20 patients with low or moderate myopia(<-6.00 D)and 10 patients with hypermyopia(?-6.00 D).The spherical equivalent(SE),tear film breakup time(FBUT),Schirmer I test,optical quality analysis system II and Oculus? Keratograph 5M were examined before surgery and 1 week,1 month,and 3 months after surgery.The data were analyzed by SPSS 19.0.When refractive status remained stable after femtosecond LASIK,patients were grouped according to Keratograph 5M dry eye classification(level 0,level 1,level 2).Measurements of visual acuity,refractive error,OSI,OVA at high and low contrast and MTFcut off were performed and analysed statistically.Results 1.Postoperation refractive status: SE of all myopia patients were significantly reduced.Three months after surgery,SE of low or moderate mopia group was +0.10±0.32,comparing with high myopia group(-0.16±.0.39).There was no statistical difference between the two group(P<0.05).2.OQAS optical quality parameters: OSI of the two groups was significantly increased at 1 week after surgery and gradually decreased after 1 month and 3 months.OSI changes are more obvious in high myopia patients.MTF cutoff,OV100%,OV20%,and OV9% in the low or moderate myopia group increased after surgery(P<0.05).No significant differences of SR were detected between the two groups(P>0.05).MTF cut off,OV100%,and OV20% also increased postoperation in high myopia group(P<0.05).There was no correlation between SE and OSI in all kinds of myopic patients(r=-0.825,P=0.000;r=-0.786,P=0.008).We found a statistically significant correlation between SE and MTF cut off,OV100%,OV20%,or OV9%.3.Keratograph 5M parameters: NIKBUTf,NIKBUTav,FBUT decreased in the low or moderate group after surgery.We found statistically difference of NIKBUTf,NIKBUTav and FBUT between different myopia group(P<0.05).However,no significant difference of TMH was detected between these two groups(P>0.05).The Schirmer I test result in the low or moderate group returned to preoperation level at 3 months without statistical significance(P>0.05),but in hyper myopia group it's still lower at 3 months with statistically significant(P<0.05).There was no statistically correlation between TMH and NIKBUTf(r=0.325,P=0.231;r=0.259,P=0.632),NIKBUTav(r=0.298,P=0.563;r=0.425,P=0.336)by K5 M examination.We found no correlation between OSDI score and TMH(P>0.05).But there were significant correlations between OSDI and NIKBUTf(r=-0.702,P=0.003;r=-0.789,P=0.000)or NIKBUTav(r=-0.698,P=0.001;r=-0.706,P=0.010).4.Visual quality changes according to Keratograph dry eye classification 3 months after surgery: When 3 months after operation,the refractive status remained stable.Corresponding to Keratograph dry eye classification,in low or moderate myopia group,OSI increased,which was 0.41±0.20 at Grade 0,0.72.± 0.14 at Grade 1,and 0.91 ± 0.21 at Grade 2;in the high myopia group,OSI also changed from 0.57 ± 0.06 at Grade 0,0.50 ± 0.24 at Grade 1,and 1.62 ± 0.99 at Grade 2.We found statistically significance of OSI in both of the two groups(F= 18.77,P=0.000;F=6.837,P=0.007).MTF cut off also decreased with dry eye.In low or moderate myopia group,MTF cut off was 37.13±5.93 at Grade 0,30.11±4.63 at Grade 1,and 19.94±6.32 at Grade2;in hypermyopia group,MTF cut off were 36.10±5.68 at Grade 0,28.72±3.63 at Grade 1,and 20.75±5.39 at Grade 2,respectively.We also found a statistically significant correlation in both groups(F=23.172,P=0.000;F=13.789,P=0.000).In hypermyopia group,OVA decreased by dry eye status,which was 1.19±0.32 at Grade 0,0.95±0.17 at Grade 1,and 0.84±0.27 at Grade 2,respectively.A statistically correlationship was detected(F=4.813,P=0.016).Conclusions 1.Femtosecond LASIK are safe,effective,and predictable surgical procedures to treat myopia.However,by OCAS II examination,OSI was found to be increased at early stage after operation,which indicated visual quality decreased.Recovery of visual quality of patients with hypermyopia would be longer than patients with low or moderate myopia.2.Femtosecond laser surgery affects the stability of the tear film at a certain time and a certain extent.The ocular surface condition is stable at 3 months after operation in the low to moderate group.Symptoms of dry eye also improved but didn't recovere to preoperative level.3.After femtosecond LASIK,the visual quality of retinal imaging could decrease accompanied with dry eye.We supposed that deterioration in visual quality after femtosecond LASIK may be related to postoperative dry eye in the early stage.OQAS II and Keratograph 5M can be used together to guide the clinic quickly,objectively,and comprehensively,which can provide quantitative analysis to the understanding of difficult cases after femtosecond LASIK.