| ObjectiveCompare the difference of scattered values and visual quality indicators when the dry spots of ocular surface appear and after the application of NS. Observe the changes of ocular surface scattering and visual quality indicators in dry eye patients after using artificial tears, respectively. Investigate the relationship between ocular surface scattering and visual quality. Methods37 eyes of preoperative patients with age related cataract and 72 eyes diagnosed as dry eye were enrolled in this study, while 38 normal eyes were divided into the control group, juxtaposing the dry eyes which were divided into the test group. Cataract patients were in their own self controlled pairing. All of these patients came to Tianjin Eye Hospital from May 2014 to August 2015.The total objective scatter index(OSI) ? Modulation Transfer Function cut off frequency value(MTFcutoff)?Strehl ratio(SR)and the objective scatter index of the tear film(TFOSI) were measured by OQAS and compared each other before and after the application of NS. Above parameters were checked by the same instrument when the control group and the test group are under the natural state. Of measurement repeatedly after the subjects' eyes were given 1 or 2 drop artificial tears. At last, we compare the differences of every indicators between the two groups before using the artificial trears,and compare the changes of every indicators in every group when the subjects were given the artificial tears. In addition, we made a correlation analysis between OSI?TFOSI and MTFcutoff?SR. ResultsThe age related cataract patients group: in the moist state,OSI and TFOSI were significantly reduced,MTFcutoff and SR was significantly increased, respectively,with a significant difference(P=0.001?0.022?0.005),comparing the dry sate of the cornea. There are significantly negative correlation between TFOSI and SR?MTFcutoff(r=-0.387?-0.432,P=0.018?0.008)in the dry state of cornea. The control group and the test group: OSI?TFOSI in the test group were higher, and MTFcutoff?SR were less than these in the control group before given artificial tears(P<0.05).In the control group,every indicators didn't change(P>0.05); in the test group,OSI?TFOSI were reduced and MTFcutoff?SR were increased significantly after the subjects' eyes were given artificial tears(P<0.05).Both the two group, OSI?TFOSI were negatively correlated with MTFcutoff and SR,significantly, whether the subjects' eyes were given artificial tears or not. The difference was statistically significant when P<0.05. ConclusionsIn general, tear film is attached to the surface of the corneal epithelium, optical surface tending to smooth, reducing the scattering of light projected onto the retina, for the reason that the retinal image contrast will not be decreased, we can maintain good visual quality. Ocular surface scattering and visual quality are negatively correlated with each other. The relationship between ocular surface scattering may explain the reasons why the applications of the saline or corneal surface protections agents can improve the clarity of the operative field function.Artificial tears can improve dry eye patients? visual quality.Ocular surface scattering may be an important indicator to assess the visual function various causes of dry eye result from all kinds of reasons. |
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