The comparision of response AC/A with different refractive error

Purpose. Recent work has shown that differences exist in the accommodation response characteristics of myopes and emmetropes, although the exact nature of the differences has yet to be ascertained. This may in part be due to the classification of the refractive error employed in many studies. Previously it has been suggested that inaccuracies in the accommodation response occur predominantly during the progression of myopia. To test this hypothesis we measure nearwork induced transient myopia (NITM) in progressing myopes (PMs), stable myopes (SMs) and emmetropes (EMMs). Methods. A total of 41 young (18–27 years) subjects participated in the study (13 PMs, 14 SMs, 14 EMMs). Following a 10 minute near task (4D) the change in accommodation response back to distance viewing was measured over a two minute time period. Results. Grouped mean data revealed a significant nearwork after-effect in PMs in comparison to SMs and EMMs after 10 seconds (p < 0.01) and 30 seconds (p < 0.01) post-task. Significantly longer time constants were also found in the PMs group. Conclusions. Our results suggest that NITM is manifest during the progressive phase of myopia development.

目的 分析不同屈光组模糊阈值之间的差异,探讨模糊阈值在近视发生发展中的可能作用机制.方法 38名志愿者参加本实验,正视组15位,等效球镜度为0.50～-0.50 D;近视组23位,其中稳定性近视组17位,屈光不正平均为(-4.76±1.40)D,进展性近视组6位,屈光不正平均为(-3.33±1.43)D.受试者在屈光全矫基础上,采用JND标准测量模糊阈值.结果 正视组模糊阈值为(0.21±0.06)D,稳定性近视组为(0.27±0.05)D,进展性近视组为(0.33±0.06)D.近视组的模糊阈值高于正视组(P=0.001),近视组中,进展性近视组的模糊阈值高于稳定性近视组(P=0.028).结论 近视对模糊的敏感度下降,其中进展性近视的敏感度下降更显著,这可能是近视调节滞后增加的部分原因。

Purpose: Caucasian children with myopia have elevated response accommodative vergence to accommodation (AC/A) ratios. The purpose of this study was twofold: to determine if response AC/A ratios vary with refractive error and with myopic progression rate in Hong Kong Chinese children, and to determine the effect of beta‐adrenergic antagonism with topical timolol application on AC/A ratios. Methods: Thirty children aged eight to 12 years participated in the study. All refractive errors were corrected with spectacle lenses. Accommodative responses were measured using a Shin‐Nippon autorefractor and concurrent changes in vergence were assessed using a vertical prism and a Howell‐Dwyer card at three metres and 0.33 metre. Accommodative demand was altered using plus or minus two dioptre lenses and lens‐ and distance‐induced response AC/A ratios were calculated. Measurements were repeated 30 minutes after the instillation of topical timolol maleate (0.5 per cent). Results: AC/A ratios appeared higher in progressing myopic children but the difference was not statistically significant. Timolol application reduced accommodative convergence (AC) in the stable myopes (reduction = ‐3 ± 1.14A) but not in the emmetropes (0.69 ± 0.9P) or progressing myopes (0.16 ± 0.43A) and this difference between refractive groups was statistically s ignificant (F2,27= 3.766; P= 0.036). However, timolol did not produce a significant change in the accommodative response to positive or negative lenses or response AC/A ratios. Conclusions: We did not find that AC/A ratios in myopic Chinese children were elevated and therefore, it is unlikely that elevated AC/A ratios are responsible for the high levels of myopia that occur in Hong Kong. The finding that timolol reduced AC in the stable myopes suggests that the autonomic control of accommodative convergence in these children may be different from that in emmetropic children and those with progressing myopia.

Objective To verify the accuracy of the results of special visual measurement instruments for heterphoric testing.Methods In this cross-sectional study,fifty healthy students served as subjects.The degree of heterphoria was measured by a special visual measurement instrument,the Maddox rod and a synoptophore.A one-way ANOVA and paired t test were used to calculate the data.Results ①The Maddox rod and synoptophore measured the highest amounts of esophoria,accounting for 38％ and 34％; hyperphoria was the least,accounting for 2％ and 4％.Measurements with the special visual measurement instrument found the highest amounts of esophoria plus hyperphoria,accounting for 36％; orthophoria was found the least,accounting for 4％.②Esophoria values measured in order from the most to the least were the Maddox rod,measurement instrument and synoptophore (F=3.18,P＜0.05).There was a significant difference between the Maddox rod and synoptophore (P＜0.05),but there were no significant differences between the Maddox rod and measurement instrument and the measurement instrument and the synoptophore (9＞0.05).Exophoria values measured from high to low were the Maddox,synoptophore and inspection instrument.There were no significant differences among the three methods (F=0.83,P＞0.05).Hyperphoria values measured from high to low were the measurement instrument,Maddox rod and synoptophore (F=6.34,P＜0.05).There were significant differences between the measurement instrument and synoptophore and the Maddox rod and synoptophore (P＜0.05),but there was no significant difference between the measurement instrument and Maddox rod (P＞0.05).③The dominant eye's value was higher than the nondominant eye's in esophoria,exophoria and hyperphoria,but only the Maddox rod measured a significant difference in esophoria (t=2.74,P＜0.01).Conclusion There were differences in the degree of heterphoria measured by the three instruments,but there was no significant difference between the measurement instrument and Maddox rod. Key words: Heterophoria; Visual function test; Com study

Objective To explore the relative contribution of refractive status and stereopsis in a school population and to determine the associations between refractive status and stereoacuity,age,and axial length.Methods Subject data were sampled from the materials of a population-based cluster sampling of children in 8 primary schools in Shanghai in this cross-sectional investigation.According to the standards established for this study,a table was created based on a questionnaire and the examination of vision,stereopsis and axial length of the subjects.SPSS 20 software was used to analyze the data for the different ages (6,7,8,9 and 10 years of age) and refractive status (emmtropia,mild myopia,severe myopia,mild hyperopia and severe hyperopia).A x2 test was used to compare groups.An ANOVA was used to compare the normal distribution measurement data among groups.For non-normal distributions data,nonparametric tests were used throughout.Results ①The trend for the incidence of myopia increased and for the incidence of hyperopia decreased with an increase in age.There was a positive correlation between the prevalence of myopia and increased age (r=0.427,P＜0.01),and a negative correlation between the prevalence of hyperopia and increased age (r=0.269,P＜0.01).There was a significant difference in stereopsis with normal uncorrected vision (Kruskal Wallis,x2=88.867,P＜0.01).There was a statistically significant difference in stereopsis between ages 6 and 7 (Kolmogorov-Smirnov,Z=2.584,P＜0.01),but no difference between ages 7 and 8,8 and 9,and 9 and 10 (P＞0.05).The difference in the detection rate of anomalous stereopsis was statistically significant for different refractive states (x2=57.294,P＜0.01).Stereoacuity also differed significantly among different refractive groups (Kruskal Wallis,x2=67.428,P＜0.01).The differences were statistically significant between severe hyperopia (Z=2.584,P＜0.01),severe myopia (Z=2.138,P＜0.01),and mild hyperopia (Z=1.819,P＜0.01) and normal groups respectively.The mean value of axial length gradually increased with an increase in age and the differences were significant among age groups (F=115.248,P＜0.01).The differences were significant when all age groups were compared to each other (P＜0.01).Conclusion ①The results suggest that the prevalence of myopia increases with age,but the prevalence of hyperopia decreases with age in school-aged children.The eye in school-aged children goes from farsightedness to myopia.②Stereopsis reaches maturity at 7 to 8 years of age.③Mild and severe hypermetropia obviously influenced the development and establishment of stereopsis.④The mean axial length of the eye gradually increased with age. Key words: Refractive error; Depth perception; Child (6-12); Small-area analysis; Data collection; Cross-sectional studies

Objective To measure the binocular accommodative amplitude under different monochromatic lights; to evaluate the differences in accommodative amplitude under different monochromatic lights and the correlation between refractive state and accommodative amplitude.Methods This was a cross-sectional study.Ninety-one subjects (182 eyes),aged 15～30 years (average 22.9±4.2 years) were enrolled in the study.All subjects underwent refractive examinations measured with MPMVA,amplitude of accommodation measured with a minus lens-stimulated test under white light (440 nm,560 nm,610 nm combined light),red light (610 nm) and green light (560 nm).A one-way ANOVA and Pearson correlation were used for statistical analysis.Results ①There were significant differences in the amplitude of accommodation under different lights (F=21.49,P＜0.01):the largest amplitude was under white light (13.04±2.75 D),green light (12.4±2.61 D) was second,and red light (11.26±2.53 D) was the lowest.②The amplitude of accommodation under the 3 hights was significantly different (F=21.476,14.356,16.540,P＜0.01) among emmetropes,low and moderate myopes and high myopes.The smallest amplitude was for emmetropes and the amplitude was for high myopes.The amplitudes of accommodation were not significantly different for emmetropes under different lights (F=1.93,P＞0.05) while the other two groups showed significant differences (F=15.684,11.821,P＜0.01).③There was a positive correlation between the amplitude of accommodation and refraction (r=0.385,0.312,0.328,P＜0.01).④For each individual,the accommodative amplitude was higher with a higher degree of myopia,under red hight,the differences were not significant (t=-1.803,P＜0.05),under white and green lights,the differences were significant (t=-2.344,2.474,P＜0.05).Conclusion The amplitude of accommodation differs when induced by different lights.It is higher with green light than red light,and there was a significant difference in myopes.The amplitude of accommodation is correlated with refractive error; the higher the degree of myopia,the larger the amplitude of accommodation. Key words: Chromatic; Light; Accommodation amplitude; Myopia; Diopter

To investigate the relationship between pupil diameter and refractive error and how refractive correction, target luminance, and accommodation modulate this relationship. Sixty emmetropic, myopic, and hyperopic subjects (age range, 18 to 35 years) viewed an illuminated target (luminance: 10, 100, 200, 400, 1000, 2000, and 4100 cd/m) within a Badal optical system, at 0 diopters (D) and -3 D vergence, with and without refractive correction. Refractive error was corrected using daily disposable contact lenses. Pupil diameter and accommodation were recorded continuously using a commercially available photorefractor. No significant difference in pupil diameter was found between the refractive groups at 0 D or -3 D target vergence, in the corrected or uncorrected conditions. As expected, pupil diameter decreased with increasing luminance. Target vergence had no significant influence on pupil diameter. In the corrected condition, at 0 D target vergence, the accommodation response was similar in all refractive groups. At -3 D target vergence, the emmetropic and myopic groups accommodated significantly more than the hyperopic group at all luminance levels. There was no correlation between accommodation response and pupil diameter or refractive error in any refractive group. In the uncorrected condition, the accommodation response was significantly greater in the hyperopic group than in the myopic group at all luminance levels, particularly for near viewing. In the hyperopic group, the accommodation response was significantly correlated with refractive error but not pupil diameter. In the myopic group, accommodation response level was not correlated with refractive error or pupil diameter. Refractive error has no influence on pupil diameter, irrespective of refractive correction or accommodative demand. This suggests that the pupil is controlled by the pupillary light reflex and is not driven by retinal blur.

Objective To investigate changes in refractive trends error of children with mixed astigmatism.Method Sixty three patients (113 eyes) with mixed astigmatism between 3 and 16 years of age were confirmed as mixed astigmatism with cycloplegic retinoscopy.Participates were performed optometric examination annually over a 3 year period.Refractive status data were collected and trends of in refractive error changes were analyzed.Result The astigmatic values remained stable over three year period (F =0.175,P =0.840),which indicated the maximum and minimum refractive trends errors could help the evolvement.There was a statistically highly significant difference in degrees of spherical lens that appeared to gradually decreased (F =14.151,P =0.000).Conclusions Refractive status can evolve into myopia as growth and development of ocular optical components in children with mixed astigmatism.Early screening and cum correction is advantageous to the children with mixed astigmatism.It is also highly recommend that cycloplegic retinoscopy is a very important and necessary method for diagnosis and therapy of children with mixed astigmatism. Key words: Children; Mixed astigmatism; Refraction

Objective To calculate the Q-value of the anterior corneal surface of children by using the tangential radius of curvature; to analyze the distribution of horizontal Q-values and the relationship between Q-value and different refractions.The vertical Q-values were calculated by curve fitting,and the Q-values of the 360° semi-meridians were then obtained,to complete the mathematical model of the anterior corneal surface.Methods The Ft-values of the 360 semi-meridians from the 84 right eyes of the children (12 cases of myopia,45 cases of hyperopia,and 27 cases of emmetropia)were calculated by Orbscan Ⅱ topography using a linear regression equation to calculate the Q-values of the semi-meridians and analyze the nasal and temporal distribution of the Q-values and the effect of refractive state.MATLAB R2009b (Matrix Laboratory) was used for curve fitting calculations of the right eye data from 62 children (10 myopes,25 hyperopes and 27 emmetropes) to obtain Q-values of 360 semi-meridians and to analyze the distribution of the Q-values.Results ① All of the coefficients of determination (R2) were greater than or equal to 0.5.The Q-values of the nasal and temporal distributions were between 1 and 0.The mean Q-values of the nasal distribution of 84 right eyes was-0.42±0.16,and the temporal distribution was-0.23±0.08.The difference was statistically significant (t=-9.527,P＜0.05).The mean r0 of the nasal distribution of 84 right eyes was 7.85±0.24and the temporal distribution was 7.83±0.24.The difference was statistically significant (t=3.213,P＜0.05).No statistical correlation was found between Q-values and r0 in this study (nasal distribution r=-0.077,P=0.487,temporal distribution r=0.001,P=0.992).②The Q values of a one-way ANOVA analysis of emmetropes,myopes and hyperopes showed that the differences between the nasal corneas of myopes and emmetropes and of myopes and hyperopes were statistically significant (P＜O.05).No significant difference was found between the emmetropes and hyperopes (P＞0.05).The differences between the temporal distributions were not statistically significant (P＞0.05).③The coefficient of determination (R2) of the curve fitting by MATLAB was greater than 0.9.④Fitting the vertical Q-values of the 48 eyes:the mean Q-values of the nasal distribution of the semi-meridian before and after curve fitting were-0.45±0.16 and-0.45±0.16 and the temporal distributions were-0.21±0.08 and -0.20±0.10.There were no significant differences before and after curve fittings (nasal distribution,t =2.009,P＞0.05,temporal distribution,t =2.009,P＞O.05).The mean vertical Q-values of the superior and inferior distributions after curve fitting were-0.24±0.10 and-0.17±0.08.Conclusion ①The method of using linear regression to calculate the Q-value of the anterior corneal surface by the tangent radius of curvature proved to be stable and reliable.Corneal asphericity was represented by a prolate ellipse and a trend toward a more prolate Q-value was found in the nasal and horizontal distributions.The Q-value had a weak correlation to ametropia.②Fhe distribution of 360 semi-meridians of the Q-value calculated from the curve fits were in the form of a double hump and the two peaks were above and below the vertical semi-meridinans.③After curve fitting calculations,the horizontal semi-meridians had more asphericity than the vertical meridians,which were more round.④The method using the Curve Fitting Toolbox of the MATLAB System to fit the Q-values proved to be stable and reliable.It solves the problem of calculating Q-values,and enables the creation of a digital model of the corneal anterior surface to become a reality. Key words: Myopia; Hyperopia; Emmetropia; Orbscan Ⅱ Topography; Tangential radius of curvature; Q-value; Curve fitting calculation

Objective To investigate the relationship between the nearwork oculomoter functions and the myopia progression in myopia juveniles. Methods 28 students were followed up and visited for 8 to 19months and their oculomoter functions such as heterophoria,the response AC/A ratio,negative relative accommodation,positive relative accommodation,accommodative lag and accommodative amplitudes were measured and analyzed. Results The response AC/A ratio,accommodative hysteresis and accommodative amplitudes were correlated with the annual myopia progression; and the Pearson's correlation coefficients (-0.416,-0.495 and -0.463 respectively) were significant at the 0.05 level. A scatterplot indicated that there was a linear relationship between the accommodative lag and the annual myopia progression;these variables were still negatively correlated while controlling for the effects of the response AC/A ratio (r=-0.383 ,P <0.05). Conclusion High accommodative lag in the nearwork maybe one of the reasons lead to myopia progression. Key words: myopia; Oculomoter function; response AC/A ratio; accommodative lag; accommodative amplitude ; Nearwork; Follow up

High myopia is an ocular disease characterized by abnormal visual functions, caused by excessive axial elongation. Retinal detachment, myopic maculopathy, glaucoma, and cataract are four major complications can cause blindness. Peripheral retinal degeneration (lattice degeneration) and vitreal traction are factors involving in the production of retinal detachment. Higher retinal detachment rate was found of the axial length between 26.0 and 27.0 mm. Early myopic maculopathy was defined as fundus change with lacquer cracks, which are seen as yellow white lines of irregular caliber whose course across the posterior pole. Refractive error more than -15.OD,, axial length over 29.0mm, and age more than 45 years old are risk factors for the development of early myopic maculopathy. Variable degrees of optic disc changes are found during myopic progression such as tilting, which made the diagnosis of glaucoma become more difficulty. Periodic visual field and three dimensional disc examination are important for high myopic patients. Nuclear type of cataract is frequent found in middle age. of high myopic patient, which may make the fast progression of, myopia.

Objective To investigate the use of racemic anisodamine eye drops combined with corrective glasses for student myopia progression effects. Methods Eighty-nine patients with low-grade myopia were selected from myopia prevention and control department of eye hospital from July 1,2007 to July 30,2007,and were randomly divided into treatment group of 51 cases and control group of 38 cases.The treatment group used 0.5％ racemic anisodamine eye drops 1time both in the morning and in the evening with each time contained 1-2 drops,continuous use for 1 year,at the same time wore corrective glasses; the control group received routine to wear corrective glasses,and neither local nor systemic drugs were used.All patients had ocular comprehensive health examination,medical optometry before the test,spherical equivalent after mydriasis (-1.98±1.22) DS.After 1 year,the two groups received examination of visual acuity,refraction,intraocular pressure,ocular axis,corneal curvature,and statistics analysis was performed.Results One year after full use of 0.5％ racemic anisodamine eye drops in 43 cases (86 eyes),vision decrease rate was 41.86％,36 cases (72 eyes) was 86.11％ in control group,there was statictically significant difference between two groups of P=0.01.Myopia progression:treatment group was (- 0.43±0.45) D; control group (-0.96±0.42) D,two groups had statistically significant at P ＜ 0.01.Axial growth:the treatment group (0.11±0.21) mm,the control group (0.66±0.24) mm,contrast was statistically significant at P ＜ 0.01.Intraocular pressure and corneal curvature in two groups before and after 1 year had no significant difference compared in two groups P ＞ 0.05.Conclusions Using 0.5％ racemic anisodamine eye drops combined with corrective glasses is safe,convenient and effective slowing down myopia progression in some students. Key words: Racemic anisodamine; Slow down myopia; Corrective glasses

Objective: To analyze refractive status and visual acuity and its relationship to binocular visual function in children with anisometropic amblyopia. Methods: A total of 106 children (106 eyes) with anisometropic amblyopia were recruited from November 2015 to September 2016 in nine hospitals in Beijing. All children were divided into the following groups based on risk factors for anisometropia: hyperopia anisometropia (67 cases), myopia anisometropia (5 cases), astigmatism anisometropia (12 cases), hyperopia combined astigmatism anisometropia (20 cases) and myopia combined astigmatism anisometropia (2 cases). Visual acuity, uncorrected and best corrected visual acuity, refractive status, and distant/near stereoscopic vision were tested. Pearson's correlation was used to analyze the correlation between dioptric differences and UCVA/BCVA in high refractive errors eye and distant/near stereoscopic vision. The correlation between BCVA difference of the two eyes and distant/near stereoscopic vision were also calculated. One-way ANOVA compared BCVA in high myopic eye and distant/near stereoscopic vision between groups. Results: There was a correlation for the dioptric difference between UCVA and BCVA, distant stereoscopic vision, and random dot stereograms (RDS) stereoscopic vision in high refractive errors (all P<0.05). There was a significant correlation between the difference in BCVA and distant stereoscopic vision and RDS stereoscopic vision (all P<0.05). There was a statistically significant difference between the five groups for BCVA, distant stereoscopic vision and RDS stereoscopic vision (F=6.221, 5.271, 3.622, 3.647, 3.464, P<0.05). Visual acuity for high refractive error eye in the myopia anisometropia group was best compared to the other four groups. The differences were statistically significant between each group (all P<0.05). Distant stereoscopic vision in the hyperopia anisometropia group was best compared to the other four groups. The differences were statistically significant between each group, except hyperopia combined astigmatism anisometropia and myopia combined astigmatism anisometropia groups (all P<0.05). RDS stereopsis in the myopia anisometropia group was best compared to the other four groups. The differences were statistically significant between each group (all P<0.05). Conclusions: Visual acuity and stereoscopic vision are correlated to the dioptric difference. Stereoscopic vision is significantly correlated with the difference in BCVA. Stereoscopic damage is different in patients based on the type of anisometropia. Key words: amblyopia; anisometropia; visual acuity; visual function; children

Objective To investigate the effect of different flickering light frequencies for inducing myopia in C57BL/6 mice.Methods It was a animal experimental study.Ninety mice at age 28 days with similar refractions in both eyes were randomly assigned to five groups of 15 mice each.The control group was exposed to white non-flickering light.Three groups were exposed to white flickering lights at a high frequency,middle frequency,and low frequency at 10,5,and 2 Hz,respectively.A form-deprivation group consisted of 30 mice that underwent monocular form-deprivation with a semitransparent hemispherical thin plastic shell covering the right eyes,and was exposed to a non-flickering white light.Refraction and axial length were measured by murine-specific eccentric infrared photorefraction and A-scan ultrasonography at baseline and after two weeks of exposure.The data were analyzed by one way ANOVA and LSD t methods.Results ①The change in refraction and axial length in mice:the baselines of the refractions of the control group,high frequency,middle frequency and low frequency flickering light groups and the form-deprivation group were 2.627±0.494 D,2.597±0.626 D,2.552±0.558 D,2.617±0.568 D,2.590±0.657 D,respectively.The baselines of the axial length for the corresponding groups were 2.805±0.029 mm,2.803±0.026 mm,2.804±0.029 mm,2.806±0.026 mm,2.804±0.025 mm,respectively.There was no significant difference in refraction or axial length among the five groups (P＞0.05).After 2 weeks of exposure,the refraction of the control group,the high frequency,middle frequency,low frequency flickering light groups and the form-deprivation group were 3.720-±0.555 D,-1.710±0.632 D,-2.020±0.705 D,-2.612±0.686 D,-2.873±0.670 D,respectively.The axial lengths for the corresponding groups were 2.924±0.022 mm,2.995±0.024 mm,3.000±-0.020 mm,3.017±0.029 mm,3.026±0.016 mm,respectively.There was a significant difference in refraction and axial length between the control group and the other groups (P＜0.01).However,the induced changes in refraction and axial length were greater in the low frequency flickering light group and the form-deprivation group compared to the high and middle frequency flickering light groups.Conclusion B6 mice could be induced to form myopia by flickering light at all frequencies we used,and the low frequency of 2 Hz was the most effective in inducing myopia that is equivalent to form-deprivation myopia. Key words: Flickering light; frequency ; Myopic model ; Mouse

Objective To comprehensively analyze the clinical efficacy of wavefront guided epipolis LASIK(Epi-LASIK) combined with iris recognition. Methods In a prospective study of wavefront guided Epi-LASIK combined with iris recognition, 37 patients (73 eyes) with myopia underwent treatment. The patients were divided into a low-to-moderate myopia group (SE<-6.00 D, 30 eyes) and a high myopia group (SE≥-6.00 D, 43 eyes). All patients were required to undergo preoperative and postoperative examinations that included UCVA, BCVA, refractive status, intraocular pressure, anterior segment slit lamp examinations, corneal topographic tests, WaveScan aberrometer tests, contrast sensitivity (CS) tests, etc. Patients were evaluated at 1 day, 1 week, and 1 month, 3 months and 6 months postoperatively. A t test, ANOVA and chi-square test were used to compare results. Results ①Postoperative UCVA:Low-to-moderate myopia patients improved and recovered UCVA faster and better than high myopia patients. At 6 months postoperatively, UCVA in low-to-moderate myopia patients was 5.05±0.11 and was 5.01±0.11 in high myopia patients. There was no significant difference between the groups (t=1.69,P>0.05). ② Refraction accuracy:refraction in all patients stabilized within 6 months postoperatively. At 6 months postoperatively, refraction in low-to-moderate myopia patients was+0.16±0.43 D and was-0.21±0.64 D in high myopia patients. ③ The height of the corneal posterior surface:there was a noticeable drop in height after refractive surgery and the surface remained stable postoperatively in all patients. There was no significant difference between the 2 groups. ④ Higher order aberrations (HOA): there was an increase in total HOA, coma and spherical aberration in all patients postoperatively. Only trefoil conversely decreased. High myopia patients developed more aberrations than low-to-moderate myopia patients. ⑤CS:the vast majority of patients had a gradual increase in CS and glare sensitivity (GS) postoperatively, reaching a peak at 3 months. Preoperative comparisons showed that CS and GS did not significantly drop in any patients postoperatively. Low-tomoderate myopia patients had better CS and GS for each spatial frequency than high myopia patients. ⑥ No patient had serious postoperative complications. Conclusion Wavefront-guided Epi-LASIK combined with iris recognition is more accurate, predictable and stable and results in better visual quality. Clinical efficacy is better for low-to-moderate myopia patients than for high myopia patients. Key words: Myopia, degenerative; Wavefront guided; Iris recognition; Keratomileusis, laser in situ