| Purpose: The anterior segment optical coherence tomography(AS-OCT)is used to measure the distance from the vertex of the lens edge to the surface of the cornea,when the orthokeratology lens fits in different states.It is hoped to quantify the fluorescein staining experiment during the fitting of the orthokeratology lens,and provide an objective and quantitative evaluation method for the fitting of the orthokeratology lens.Method: This was an observational study.Examination of patients who try on orthokeratology,Check items before try-on include medical history,slit lamp,naked vision,computer optometry,non-contact intraocular pressure,corneal topography,optometry,tear film rupture time,etc..Excluding the contraindications of wearing orthokeratology lenses,select standard films and try them on.Check items after try-on include the comfort survey,computer optometry,corneal topography,AS-OCT,and corneal fluorescein staining,etc..According to the performance of fluorescein staining,the inspected eyes are divided into three groups: lens fitting group,lens loose group,and lens tight group.Using the built-in software HEYEX1.9.10.0 to analyze the AS-OCT image,and the distance from the vertex of the orthokeratology lens to the surface of the cornea is measured.To compare the distance from the vertex of the orthokeratology lens to the surface of the cornea with corneal fluorescein staining performance,divide the distance into three groups,and evaluate the differences between the three groups of data.SPSS17.0 statistical software was used for data analysis.The basic parameters of the three groups before wearing glasses were compared by one-way analysis of variance,and the sex composition between the three groups was analyzed by chi-square test,the distance from the edge arc of the three groups of orthokeratology lenses to the corneal surface was compared by analysis of variance,and the difference was statistically significant with P<0.05.Results: Forty-seven patients who tried on Ortho Keratoplasty were enrolled in this study.There were 25 males and 22 females.The age ranged from 7 to 18 years with an average age of 11.7±2.67 year old.The average spherical degree is(-2.46±1.38)D,the average cylinder degree is(-0.73 ± 0.53)D,the average horizontal meridian power magnitude(HK)is(42.35 ± 1.45)D,and Vertical meridian power magnitude(VK)is(43.36±1.54)D.Included 21 cases in the lens fitting group(36 eyes,15 cases of both eyes,4 cases of single right eye,2 cases of single left eye),10 cases of lens loose group(18 eyes,8 cases of both eyes,2 cases of single right eye)),21 cases in the lens tight group(32 eyes,11 cases of both eyes,5 cases of single right eye,5 cases of single left eye).There was no statistical difference in the main basic data of the subjects in the three groups(all P>0.05).Use AS-OCT to measure:(1)Lens fitting group: When the fluorescein staining shows the lens fitting state and the wearer is more comfortable,the distance from the vertex of the orthokeratology lens to the corneal surface is 217.24±11.03 μ m.(2)lens loose group: When the fluorescein staining shows that the lens curvature is too large or the lens diameter is too small,and the wearer’s comfort is poor,the distance is 245.94±17.55μm.(3)Lens tight group: When the fluorescein staining shows that the lens curvature is too small or the lens diameter is too large,and the wearer’s comfort is normal,the distance is 195.64±11.73μm.The difference between the three groups of values in the analysis of variance,P<0.0001,the results obtained are statistically significant.Conclusion: Anterior segment optical coherent tomography(AS-OCT)can be used to measure the distance from the apex of the edge of the orthokeratology lens to the surface of the cornea to assess whether the orthokeratology lens fits.It provides a more objective and quantitative analysis method for evaluating the fitting of orthokeratology lens. |
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