It was found about 25 years ago that the retina can detect the position of the plane of best focus,averaged over time,and adjust axial eye growth to achieve and maintain the best match of photoreceptor and focal planes.This occured mainly independently and locally all over the visual field,and was limited by low pass filtering through optical aberrations,eye movements and mechanical and structural constraints.

 Objective To investigate the effect of different spectral compositions of light on the release of dopamine by human retinal pigment epithelial (RPE) cells in vitro.Methods Experimental study.Cultured human RPE cells (RPE-19) were exposed to either full spectrum light or red,green,blue (RGB) spectrum light in the intensities of either 4000 lx or 1000 lx.Cells exposed to no light irradiation were used as the control.Cells were assayed at 24 hours and 48 hours for the secretion of dopamine using high performance liquid chromatography (HPLC) and cell viability by WST-1 (a sodium salt of 4-[3-4-iodophynyl)-2-(4-nitrophenyl)-2H-5-tetrazolio]-1,3-benzene disulfonate assay).Data were analyzed using one-way ANOVA.Results There was no statistical significance in the difference of proliferation rates between the full spectrum group and the RGB group at 1000 lx for the first 24 hours,while the difference was statistically significant at the 4000 lx level (P＜0.05).In contrast,full spectrum light significantly suppressed the proliferation of cells compared to RGB light at 48 hours,both in the low and high light intensities (both P＜0.01).After 24 hours treatment,the difference in the concentration of dopamine was not significant between the full spectrum group and the RGB group at an intensity of 1000 lx,while the difference was statistically significant at 4000 lx (P＜0.01).Furthermore,the concentration of dopamine at 48 hours was higher in the full spectrum groups than in the RGB groups at both intensity levels (both P＜0.05).Conclusion The present study found that the spectral composition of light is involved in regulating the release of dopamine by RPE and the effect was closely correlated with light intensity and time.These results demonstrate the importance of considering spectral composition when investigating sunlight's protective effect against the development of myopia.

Objective To examine if there is any association between myopia and genetic variations in the early growth response 1 (EGR1) and crystallin alpha A (CRYAA) genes.Methods Genomic DNA was collected from 2870 unrelated individuals,including 1052 university students without myopia (NC group),615 university students with moderate myopia,640 university students with high myopia,and 563 unrelated patients with early onset high myopia.Three tag SNPs,rs872331 and rs3788061 in CRYAA as well as rs11743810 in EGR1,were genotyped by restricted fragment length polymorphism (RFLP) and cycle sequencing.The results from the myopes and controls were compared with a chi-square test.Results No statistically significant difference was found for genotypes or allele frequencies of the three tag SNPs between myopes and controls (rs11743810:P=0.700,0.922; rs872331:P=0.377,0.166; rs3788061:P=0444,0.303).These results were not affected when each myopia group was compared to the control group respectively.Conclusion No evidence was found to support the association between myopia and variations in EGR1 and CRYAA.Unlike the observations in experimentally induced myopia in animals,EGR1 may not play a major role in the predisposition to myopia in humans.

Objective To analyze mitochondrial DNA (mtDNA) in the displacement loop (D-Loop)region in pathological myopia subjects and controls.Methods Experimental study.Genomic DNA was extracted from 127 pathological myopia subjects and 104 controls.PCR-amplification of the D-Loop region and bidirectional sequencing was done according to the revised Cambridge reference sequence (rCRS) and all variants were analyzed.Data were analyzed using independent samples t test and frequency of variants using Chi-square test and Bonferroni correction.Results One hundred and sixty-eight variants were found in 127 pathological myopia subjects.Of these,3 were new variants and 53 variants were only found in the pathological myopia subjects and not in the controls.There were 1270 variants in 127 pathological myopia subjects,with an average of 10 variants in each subject.None of the variants was statistically associated with pathological myopia.The frequency of mtDNA T152C in pathological myopia subjects and controls was 19.7％(25/127) and 31.7％(33/104),respectively.Chi-square tests showed there were significant differences between the pathological myopia and control groups (x2=4.412,P=0.036),but Bonferroni correction did not show significant differences.Conclusion The displacement loop region of mitochondrial DNA in pathological myopia is a hot spot for mutations.Additional studies should be done on mitochondrial DNA D-Loop variants and pathological myopia.

Objective To explore the possible mechanisms of myopia.Form-deprivation myopia was induced in guinea pigs and N-methyl-D-aspartate receptor 1 (NMDAR1) antisense oligonucleotides were injected intravitreously.Methods In this experimental study,3-week-old guinea pigs were divided into six groups (each n=10):group A was the control group; group B underwent monocular form-deprivation (MD) for 3 weeks; group C1 received intravitreous injection of 100 ng NMDAR1 sense oligonucleotides to MD eyes; group C2 received intravitreous injection of saline to MD eyes;group C3 received intravitreous injection of 10 ng NMDAR1 antisense oligonucleotides to MD eyes;group C4 received intravitreous injection of 100 ng NMDAR1 antisense oligonucleotides to MD eyes.Groups C1～C4 received the intravitreous injection at the second week of deprivation.Refraction and axial length of the eyes were measured and the expression of NMDAR1 was assayed by immunohistochemistry and RT-PCR before the test and 3 weeks later.Differences between groups were assessed using one-way ANOVA,and the correlation between NMDAR1 antisense oligonucleotides and refraction,axial length were analyzed with linear correlation.Results There were statistical differences in the degree of myopia,axial length and level of NMDAR1 protein and mRNA among groups A,B,C1～C4 (F=55.247,142.213,43.215,592.435,P＜0.05).In group B and groups C1～C4,myopia was more severe and eye axial length was longer in MD eyes.There were no significant differences in the degree of myopia,axial length or the level of NMDAR1 protein and mRNA among groups B,C1 and C2.The degree of myopia was gradually less severe,axial length was gradually shortened and the level of NMDAR1 was gradually down regulated among groups C2,C3 and C4 and the effect was concentration-dependent.The degree of myopia had a positive correlation to the concentration gradient (r=-0.695,P＜0.05) while axial length and the level of NMDAR1 expression had a negative correlation (r=-0.731,-0.625,-0.821,P＜0.05).Conclusion Significant up-regulation can be observed in the expression of NMDAR1 in the level of mRNA and protein in MD eyes.With NMDAR1 antisense oligonucleotides injected intravitreously,the expression of NMDAR1 is down-regulated along with reduced development of myopia.

Objective To investigate the differences in contrast visual acuity (CVA) under both bright and dark conditions in recent-onset myopic,progressive myopic and emmetropic teenagers; to investigate the correlation between CVA and wavefront aberration,together with pupil size; to study the possible mechanisms involved.Methods A cross-sectional trial design was used in this study.CVA was measured in 58 left eyes from 58 teenagers aged from 12 to 16 yeats.They were divided into 3 groups:emmetropes,18 subjects,with an average spherical equivalent refractive error (SER)of (0.00±0.20)D; recent onset myopes,21 subjects,with an average SER of (-1.03±0.33)D; and progressive myopes,19 subjects,with an average SER of (-2.67±0.77)D.All subjects underwent CVA testing with full spectacle correction under both bright and dark conditions with a Multi-Functional Visual Acuity Analyzer (MFVA-100).Pupil size and monochromatic wavefront aberration were measured with a real-time image recording system and a Hartmann-Shack wavefront aberrometer.Data were analyzed using paired samples t test,repeated measure variance analysis,one-way ANOVA and Pearson correlation.Results Myopes had a lower CVA than emmetropes.And recent-onset myopes had a lower CVA than progressive myopes and emmetropes (F=199.17,234.54,P＜0.01),especially under low contrasts (25％,10％) and dark conditions.Root mean square (RMS) values of total aberrations (C2-C7 without C20) and total higher-order aberrations (HOA),spherical aberration and coma increased significantly with a pupil in dark light [(0.205±0.108)μm,(0.101±0.057)pm,(0.028±0.039)μm and (0.066±0.056)μm] than with a pupil in bright light [(0.599±0.257)μm,(0.355±0.141)μm,(0.148±0.122)μm and (0.195±0.034)μm) (t=14.94,16.71,7.89,6.28,P＜0.05).There was no significant difference in the RMS values of HOA between emmetropes and myopes.Except for under bright and 100％ contrast conditions,CVA had significant negative correlation with HOA,no correlation was found between aberration,pupil and CVA for all the groups under bright or dark conditions.Conclusion The CVA in recent-onset myopic teenagers was lower than both progressive myopic and emmetropic teenagers,especially under dark conditions and low contrasts.So far there is not enough evidence to show that the decrease in CVA in recent-onset myopes is related to pupil size and the deterioration of retinal image quality causcd by wavefront aberrations.We assume that cortical factors may play the major role in this phenomenon.

Objective To measure and compare the visual quality in myopic patients corrected by laser in situ keratomileusis (LASIK) and rigid gas permeable contact lens (RGPCL) by using point spread function (PSF).Methods This was a prospective study.There were 2 groups of patients with middle-high myopia corrected using either LASIK or RGPCL:44 eyes of 22 patients received LASIK (group A),with the spherical equivalent (SE) (-6.84±1.65)D,while 49 eyes of 25 patients corrected by RGPCL (group B),with the SE(-6.43±1.59)D.The changes of the modulation transfer function (MTF) in their eyes were evaluated before and 3 months after LASIK in group A,before and after the fitting of RGPCL in group B by using the PSF examination under conditions of 3 mm and 6 mm pupil diameters respectively.The changes of PSF in each group before and after correction were compared and the differences between groups were statistically analyzed with paired samples t test and analysis of covariance.Results ① The MTF values at low-middle spatial frequencies were decreased 3 months after LASIK (3 nun pupil diameter,2.98～23.81 cpd; 6 mm pupil diameter,2.98～9.42 cpd,P＜0.01),which was a statistically significant decrease,whereas the changes of MTF at high frequencies were not significant.②Under the condition of 3 mm pupil diameter,the MTF values at high spatial frequencies were increased after fitting of RGPCL (18.85～37.70 cpd,P＜0.05),whereas at low-middle frequencies the difference was not significant.Under the condition of 6 mm pupil diameter,the MTF values were improved at all spatial frequencies after RGPCL (2.98～37.70 cpd,P＜0.05).③The changes of MTF values at all spatial frequencies in the RGPCL group were better than those in the LASIK group (P＜0.05).Conclusion LASIK can deteriorate the visual quality of myopic patients in the early stage after surgery,whereas RGPCL can improve it.The visual quality of myopic patients corrected by RGPCL is better than that of the early stage after LASIK.

Objective To evaluate the safety,efficacy,and stability of AcrySof Toric intraocular lens (IOL) implanting in correcting residual astigmatism in patients who have cataract surgery.Methods This was a prospective case control study.Sixty-nine eyes of 59 consecutive cataract patients during a 12-month period who had more than 0.75 diopters (D) of pre-existing astigmatism of the cornea were included.After phacoemulsification,33 patients (37 eyes) were implanted with AcrySof Toric IOL (test group) and 26 patients (32 eyes) with AcrySof SN60AT IOL (control group).One day,1 week,1 month,and 3 months after IOL implantation,uncorrected visual acuity (UCVA),best corrected visual acuity (BCVA),residual refractive sphere and cylinder,corneal keratometry,and the AcrySof Toric IOL axis were measured.Visual acuity and residual refractive cylinder distribution were analyzed by Fisher's exact probability and refractions were analyzed by independent samples t tests.Results UCVA:three months after implantation,1 eye (3％) in the test group and 10 eyes (31％) in the control group presented with 0.1-0.3; 22 eyes (60％) in the test group and 15 eyes (47％) in the control group presented with 0.4-0.6; 5 eyes (14％) in the test group and 6 eyes (19％)in the control group presented with 0.7-0.9; and 9 eyes (24％) in the test group and 1 eye (3％) in the control group presented with 1.0 or better.There were statistically significant differences between the two groups (Fisher's exact=0.000,P＜0.05).Residual refractive cylinder:68％ of the test group eyes and 12％ of the control group eyes had 0-0.75 D; 32％ of test group eyes and 59％ of the control group eyes had 1-1.75 D; and 0％ of the test group eyes and 28％ of the control group eyes had more than 2 D.There were statistically significant differences between the two groups (Fisher's exact=0.000,P＜0.05).Rotational stability:3 months after implantation,all AcrySof Toric IOL had rotated less than 20 degrees:IOL in 21 eyes (57％) had rotated less than 5 degrees,IOL in 7 eyes (19％) had rotated 6°-10°,and IOL in 9 eyes (24％) had rotated 11°-15°.The mean AcrySof Toric IOL axis rotation was 5.8°±5.0° (0°-15°).Surgically induced astigmatism (SIA):the mean SIA was (0.66±0.17)D in the test group and (0.62±0.24)D in the control group.There was no statistically significant differences between the two groups.Conclusion The results show that phacoemuisification and AcrySof Toric IOL implantation are safe and effective to correct residual astigmatism 3 months after cataract surgery.

Objective An aspheric intraocular lens (IOL) with fixed spherical aberration (SA) implanted in an individual patient will not always obtain ideal optical quality since human corneal structure and SA have large individual variations.The aim of this research was to study optical performance of individual pseudophakic eye models that were constructed based on individual anatomic parameters and implanted IOL with different optical designs.Methods Computer numerical simulation experiment.The anatomic parameters of individual pseudophakic patients were obtained by Pentacam and IOL Master.Parameters were input into ZEMAX to build individual eye models.Three aspheric IOL (SofPort AO,Tecnis Z9000,FY60AD) and one spherical IOL (YA60BBR) were implanted into individual eye models.Modulation transfer function (MTF) and contrast sensitivity function (CSF) were calculated for 3 mm to 5 mm pupil diameters and 550 nm wavelength.Results The height of the MTF and CSF curves were decreased with larger pupils.They were similar with the 4 IOL implanted in the individual eye models for 3 mm pupil diameter,but they were different from each other for 4 and 5 mm pupils,indicating that individual people with different anatomic structures need certain types of IOL to obtain optimal optical performance.This phenomenon was more pronounced for larger pupil.Conclusion The individual eye model based on an individual patient's anatomic parameters should mimic the optical performance of an individual's eye.The type of IOL is varied to obtain optimal optical performance for the optical system of the human eye with different anatomic structures.We should choose an IOL based on the individual eye's structure to obtain optimal retinal image clinically.

Objective To establish a biomechanical finite element model of myopic laser in situ keratomileusis (LASIK) and to study the relationship between various parameters and the elevation change of posterior corneal surface.Methods Computer numerical simulation study.Sixty-eight subjects (116 eyes) were measured with Orbscan ⅡZ corneal topography system.Selecting 110 eyes randomly from 116 eyes,all special points' coordinates of the 110 corneas were introduced to SAS statistical software to calculate the corneal surface equations through non-linear regression method and to compare the forecast results with the actual values.Constructing the corneal 3D model by ANSYS software,simulating LASIK by mathematical method,setting up biomechanical parameters,restraining boundary conditions,loading capacity,establishing the laser refractive corneal surgery model based on the biomechanical properties.The Z-axis displacement of posterior corneal surface apex was used as an observing index.Results The general equation of the anterior surface:X2/8.78+Y2/8.68+(Z+9.79)2/9.792=1 (Residual=115.50,R2=0.99),posterior surface:X2/8.40+Y2/8.19+(Z+ 11.89)2/11.352=1(Residual=96.63,R2=0.99).The correlation r between the measured Z-axis values and predicted Z-axis values of anterior and posterior corneal surface were both 0.99.The Z-axis displacement of posterior corneal surface apex correlated positively with flap thickness,optical zone diameter,intraocular pressure,negatively with the modulus of elasticity and refractive errors correction in the surgery simulation.The parameter that had the most effect on the hyperopic shift of the posterior surface was the modulus of elasticity.Conclusion The myopia anterior and posterior corneal surfaces are both ellipsoid.The finite element model shows that the modulus of elasticity has the most effect on the hyperopic shift of the posterior surface.The study will be able to provide other relevant basic information.

Objective To evaluate the safety,efficacy,predictability and stability of astigmatic keratotomy (AK) for the correction of astigmatism during anterior chamber phakic intraocular lens (ACPIOL) surgery.Methods This was a prospective case control study.Fifty-two eyes of 30 patients with 1.0 D or more of refractive astigmatism,underwent AK during ACPIOL surgery (treatment group).Twenty-three eyes of 15 patients with less than 1.0 D refractive astigmatism,underwent ACPIOL surgery only (control group).The CRAVY vector analysis of the flattening effect plotted on the target axis was used to assess the effectiveness of the treatment.Data were analyzed with repeated measure variance analysis,Wilcoxon rank sum test,Mann-Whitney U test.Results Average preoperative best corrected visual acuity (BCVA) of the treatment group was 4.69±0.24,reaching 4.81±0.15 (P=0.007)and 4.85±0.16 (P＜0.01) at 1 week and 9 months postoperatively.Average preoperative BCVA of the control group was 4.82±0.17,reaching 4.88±0.16 (P=0.261) and 4.93±0.14 (P=0.069) at 1 week and 9 months postoperatively.The average spherical equivalent (SE) of the treatment group was (-16.89±4.45)D,reaching (-0.61±1.14)D (P＜0.01) and (-0.68±1.06)D (P＜0.01) at 1 week and 9 months,respectively.Average preoperative SE of the control group was (-15.33±3.36)D,reaching (-0.57±0.89)D (P＜0.01) and (-0.77±0.70)D (P＜0.01) at 1 week and 9 months postoperatively,respectively.Eyes in the treatment and control groups showed a statistically significant refractive and corneal astigmatism reduction at the 9-month follow-up evaluation (P＜0.05).In the treatment group,the safety index was 1.03,the correction index was 79％ and the magnitude of error was -0.44 D.Conclusion AK performed during ACPIOL surgery appears to be a safe,effective and stable procedure to reduce pre-existing astigmatism,which remained consistent throughout the follow-up period.Further study is required to improve its predictability.

Objective To investigate the influence of laser in situ keratomileusis (LASIK) and sub-Bowman keratomileusis (SBK) on corneal higher-order aberrations.Methods This prospective study involved 38 subjects (76 eyes) treated with LASIK and 41 subjects (73 eyes) treated with SBK.Higher-order aberrations data were obtained from corneal topography before and after the operations.Higher-order aberrations were analyzed with Zernike polynomials.The data were analyzed with a paired samples t test and an independent samples t test.Results The uncorrected visual acuity postoperation were better than 0.8 for all eyes.The preoperative and postoperative differences in vertical coma (Z31),horizontal coma (Z-13),coma (|Z|13),trefoil (|Z|33),and spherical aberration (Z04) in the LASIK group were significant (t=10.201,2.990,-8.525,-2.140,-16.736,P＜0.01).The corresponding differences were also significant for the SBK group (t=12.840,2.899,-12.518,-2.944,-23.854,P＜0.01).The differences in the change in values (postoperative minus preoperative) of Z13,Z-13,|Z|13,|Z|33,Z04 between the LASIK and SBK groups were not significant.Conclusion Both LASIK and SBK can increase postoperative corneal higher-order aberrations,but there is no significant difference in the change in higher-order aberrations between the two types of operations.

Objective To investigate the relationship between meibomian gland dysfunction (MGD) and conjunctivochalasis (CCh),and to observe the therapeutic effect of meibomian gland pressing.Methods This was a prospective,randomized,case control study.Two hundred eyes of 100 patients with CCh were included in this study in which the ocular surface disease index (OSDI),meibomian gland outlet score,smears of meibomian gland secretion,and tear break-up time (BUT)were observed and also used to evaluate the therapeutic effect of pressing treatment for MGD.CCh patients with MGD were randomly divided into two groups:24 patients (48 eyes) were treated with pressing treatment and 22 patients (44 eyes) were treated with artificial tears eye drops and antibiotic eye drops (the control group).All patients were followed up at 1,2,4,and 8 weeks.The data from OSDI and BUT for the two groups at the 8-week follow-up were used to conduct with an independent samples t test or paired t test.Results Of the 200 eyes,92 eyes (46％) with MGD.While OSDI scores in CCh without MGD (21.6±5.9) were significantly lower than that in those with MGD (46.3± 7.9) (t=17.172,P＜0.01),OSDI scores in eyes with pressing treatment (21.2±4.8) were significantly lower than that pre-treatment (45.8±8.9) (t=22.170,P＜0.01 ).After pressing treatment,the meibomian gland outlet scores (2.1±0.3) were significantly lower compared with the pre-treatment scores (3.2±0.4)(t=2.688,P=0.025).BUT in pressing-treated eyes significantly improved to be (7.1±0.9) seconds compared with (5.7±0.9) seconds of baseline (t=10.110,P＜0.05).In the control group,there was a significant difference in OSDI (t=24.330,P＜0.01) rather than in BUT and meibomian gland outlet scores between pre- and post-treatment.In addition,lipid,epithelia,apoptosis cells,broken cells and inflammatory cells were observed in some smears of meibemian gland secretion.Conclusion MGD can accompany CCh and exacerbate its symptoms,whereas pressing the meibomian gland is an effective method for treating MGD and attenuating the related symptoms of CCh.

Objective To determine the causes of severe visual impairment and blindness (SVI/BL) among students in a school for the blind in Shanghai with a view to promote the control of childhood blindness and low vision.Methods A cross-sectional investigation of 163 students was conducted in April 2010.The data were included in the self-designed survey form from World Health Organization/Prevention of Blindness (WHO/PBL) eye examination record system,which includes classifications and etiological categories for visual impairment and blindness,and classifications of the affected anatomic sites of the eye involved in visual impairment and blindness.Distance uncorrected and corrected visual acuity were measured.Autorefraction and subjective refraction were performed if needed.The anterior segment was examined using a handheld slit lamp.The posterior segment was examined by ophthalmoscopy.Number were counted and measured with percentage.Results Of the 163 students,19.6％ were severe visual impairment,54.6％ were blindness,21.5％ had moderate visual impairment and 4.3％ were mildly impaired.The leading etiological causes of SVI/BL were congenital and hereditary factors (37.2％).The anatomical site for SVI/BL was the retina in 41.3％ of the students.The main disease causing SVI/BL was retinopathy of prematurity (ROP) (18.2％).Blinding disease was considered as "avoidable" in 64 studnets (52.9％),of which 29 cases (24.0％) were preventable,and 35 cases (28.9％) were treatable.The main treatable disease in moderate visual impairment was congenital cataract (15 cases,42.9％).Conclusion The pattern of childhood blindness in Shanghai is similar to that seen in other developed countries.It is recommended to move more quickly to establish a reliable ROP screening and treatment network,and vigorously promote low vision rehabilitation.

Objective To understand the status of knowledge,attitude and practice (KAP) about binocular visual function among school-age children,and to provide a reference for scientific care in health education.Methods An investigation was conducted to survey school-age children in four elementary schools in a district of the city of Shanghai,randomly selecting one class from every grade and using a specially designed questionnaire to learn about binocular visual function KAP.Data were analyzed using a chi-square test,an independent samples t test,and an ANOVA.Results Six hundred twenty-four questionnaires were sent out and 503 questionnaires were retrieved and valid.The ratio of valid questionnaires was 80.6％.There were no significant differences in binocular visual function K,A,P scores when comparing the four grades and comparing the boys and girls.For every grade,K,A and P scores were not equal (F=47.828,48.568,48.004,50.330,P＜0.05).LSD-t tests showed that K scores differed significantly from A scores (P＜0.05) but not from P scores (P＞0.05),A scores differed significantly from P scores (P＜0.05),and A scores of the school-age children were higher than K and P scores.Conclusion Knowledge of binocular visual function and practice of school-age children are relatively poor,but their attitude is fairly good.Health education should be designed so the binocular visual function KAP curriculum is appropriate for school-age children.

Objective To evaluate the efficacy of a software-based system for treating amblyopia in children.Methods This was a prospective case control study.A software program was created based on the contemporary theory for the treatment of amblyopia.Fifty-one patients (86 eyes) were recruited for the study and they were randomly divided into two groups.The software program was used for the treatment group (44 eyes of 24 patients),while He-Ne laser exposure and Haidinger's brush were used for the control group (42 eyes of 27 patients).All patients were followed up for 3-6 months after one course of treatment.The effective rate between the two groups was compared,and pattern visual evoked potentials before and after the treatment in treatment group were recorded.An independent samples t test,chi-square test and Fisher test were used to analyze the data.Results The overall effective rate was 73％ in the treatment group and 57％ in the control group,the differences were insignificant.However,the differences between the rates of effectiveness were statistically significant in moderate amblyopic children (77％ in the treatment group,42％ in the control group,x2=5.662,P＜0.05) and ametropic amblyopes (74％ in the treatment group and 44％ in the control group,x2=4.337,P＜0.05).The mean P100 latency of the treatment group was slightly shortened after the therapy,but the differences were not statistically significant.The mean amplitudes after treatment showed definite increases and the differences were statistically significant (t=2.11,2.47,2.34,P＜0.05).Conclusion The function of the software-based amblyopia treatment system is comprehensive,and it is an effective device for amblyopia treatment.

Numerous studies on form deprived and lens induced myopia models demonstrate that signals in the retina regulate the growth locally within the eye.Dopamine as one of the main neurotransmitters in the retina may play an important role and is likely to become a new drug to slow the progression of myopia.In the first section,this review briefly introduces dopamine,dopaminergic neurons and dopamine receptors in the retina.Then it summarizes the changes in retinal dopamine release in experimental myopia and the mechanism of how dopamine might work.Plenty of evidence indicates dopamine does play an important role in the development of experimental myopia.Even though all the studies are not consistent,most tend to support its preventive effects on myopia.However,the specific mechanism is still unclear and further study remains to be done.