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Background@#More than ten genome-wide association studies have identified the significant association between the gap junction delta-2 (GJD2) gene and myopia. However, no functional studies have been performed to confirm that this gene is correlated with myopia. This study aimed to observe how this gene changed in mRNA and protein level in the form-deprivation myopia (FDM) animal model.@*Methods@#Four-week-old guinea pigs were randomly divided into two groups: control and FDM groups (n = 12 for each group). The right eyes of the FDM group were covered with opaque hemispherical plastic lenses for 3 weeks. For all the animals, refractive status, axial length (AL), and corneal radius of curvature were measured at baseline and 3 weeks later by streak retinoscope, A-scan ultrasonography, and keratometer, respectively. Retinal GJD2 mRNA expression and connexin 36 (Cx36) levels in FDM and control groups were measured by quantitative real-time PCR and Western blot analyses, respectively. Those results were compared using independent t test, Mann-Whitney U test, or paired t test. A significance level of P < 0.05 was used.@*Results@#Three weeks later, the FDM group (form-deprived eyes) showed about a myopic shift of approximately -6.75 (-7.94 to -6.31) D, while the control group remained hyperopic with only a shift of -0.50 (-0.75 to 0.25) D (Z=-3.38, P < 0.01). The AL increased by 0.74 (0.61–0.76) and 0.10 (0.05–0.21) mm in FDM and control groups, respectively (Z = -3.37, P < 0.01). The relative mRNA expression of GJD2 in the FDM group decreased 31.58% more than the control group (t = 11.44, P < 0.01). The relative protein expression of CX36 on the retina was lowered by 37.72% in form-deprivation eyes as compared to the controls (t = 17.74, P < 0.01).@*Conclusion@#Both the mRNA expression of GJD2 and Cx36 protein amount were significantly decreased in the retina of FDM guinea pigs. This indicates that Cx36 is involved in FDM development, providing compensating evidence for the results obtained from genome-wide association studies.
ABSTRACT
BACKGROUND@#More than ten genome-wide association studies have identified the significant association between the gap junction delta-2 (GJD2) gene and myopia. However, no functional studies have been performed to confirm that this gene is correlated with myopia. This study aimed to observe how this gene changed in mRNA and protein level in the form-deprivation myopia (FDM) animal model.@*METHODS@#Four-week-old guinea pigs were randomly divided into two groups: control and FDM groups (n = 12 for each group). The right eyes of the FDM group were covered with opaque hemispherical plastic lenses for 3 weeks. For all the animals, refractive status, axial length (AL), and corneal radius of curvature were measured at baseline and 3 weeks later by streak retinoscope, A-scan ultrasonography, and keratometer, respectively. Retinal GJD2 mRNA expression and connexin 36 (Cx36) levels in FDM and control groups were measured by quantitative real-time PCR and Western blot analyses, respectively. Those results were compared using independent t test, Mann-Whitney U test, or paired t test. A significance level of P < 0.05 was used.@*RESULTS@#Three weeks later, the FDM group (form-deprived eyes) showed about a myopic shift of approximately -6.75 (-7.94 to -6.31) D, while the control group remained hyperopic with only a shift of -0.50 (-0.75 to 0.25) D (Z = -3.38, P < 0.01). The AL increased by 0.74 (0.61-0.76) and 0.10 (0.05-0.21) mm in FDM and control groups, respectively (Z = -3.37, P < 0.01). The relative mRNA expression of GJD2 in the FDM group decreased 31.58% more than the control group (t = 11.44, P < 0.01). The relative protein expression of CX36 on the retina was lowered by 37.72% in form-deprivation eyes as compared to the controls (t = 17.74, P < 0.01).@*CONCLUSION@#Both the mRNA expression of GJD2 and Cx36 protein amount were significantly decreased in the retina of FDM guinea pigs. This indicates that Cx36 is involved in FDM development, providing compensating evidence for the results obtained from genome-wide association studies.
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Background Orthokeratology has been proved to temporarily alter the equivalent sphere,but its effects on visual quality deserve attention.Objective The present study was to investigate the visual quality after overnight orthokeratology in pre-adolescent myopes.Methods Written informed consent was obtained form each subject prior to entering into this series.A descriptive study design was used.One hundred and fifty eyes of 76 teenagers aged (14.90± 1.24)years with low and moderate myopia (-2.79 ± 0.82)D were included in the study.Fitted with Ortho-K contact lens,the lens was wore every night for over 8 hours.Subjective refraction,uncorrected visual acuity (UCVA),contrast sensitivity function,corneal-topography,and aberrometry were examined before,1 week and 3 months after the initiation of orthokeratology.Visual quality was generally evaluated by comparing before wearing,1 week and 3 months after wearing using the National Eye Institute refractive error quality of life instrument (NEI-RQL-42TM).All the procedures were performed by the same clinician.Results Spherical equivalent refractions were (-0.33± 1.02) D and (-0.26 ± 0.60) D 1 week and 3 months after orthokeratology,showing significant decline in comparison with (-2.79±0.82) D of before orthokeratology (P =0.001,0.001).However,no considerable difference was seen between 1 week and 3 months after orthokeratology (P=0.161).Contrast sensitivity function was significantly different in all spatial frequencies before wearing,1 week and 3 months after wearing,and those of 1 week and 3 months after wearing were significantly lower than those of before wearing (1 week:3 cpd P =0.001,6 cpd P=0.001,12 cpd P＜0.05,18 epd P＜0.05 ;3 months:3 cpd P=0.001,6 cpd P=0.001,12 cpd P＜0.05,18 cpd P＜0.05).There was no significant change in contrast sensitivity function between 1 week and 3 months of orthokeratology (P＞0.05).Flat K,steep K and corneal eccentricity (e) were significantly reduced (P =0.000),and surface asymmetry index (SAI) and surface regularity index (SRI) were significantly improved after orthokeratology in comparison with before orthokeratology (both P =0.001).Root mean square (RMS) of total higher-order,third-order and fourth-order aberrations were significantly increased (P＜0.05),but RMS of whole aberration and second-order aberrations significantly decreased after orthokeratology (P＜ 0.05).There were no significant changes in the fifth-order,sixth-order and seventh-order aberration among pre-wear,1 week and 3 months after orthokeratology.Scales of dark to bright,nocturnal driving,glare,visual fluctuate and halo were lower than those before orthokeratology (P＜0.05).The scales of visual fluctuate between 1 month and 3 months after orthokeratology had significant differences (P＜0.01),while the rest of the scales had no significant differences (P＞0.05).Conclusions Orthokeratology can reduce myopic diopter 1 week after orthokeratology.The overnight wearing of fitted orthokeratology can decrease contrast sensitivity and increase corneal surface irregularity and RMS of third-order and fourth-order.Compared with spectacles,orthokeratology reduces subjective visual quality,especially nocturnal quality.
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The most common forms of treatment for amblyopia are occlusion therapy and pharmacologic penalization. But these methods can not recover all the visual deficits of amblyopes and there are some disadvantages of the treatment which need to be considered, including adverse effects, compliance and social stigma. Recently, some novel approaches are investigated for improving the effectiveness and compliance of treatment for amblyopia.
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·AIM: To report two patients with Helveston syndrome who received surgical treatment.·METHODS: During last year in department of oph-thalmology in West China Hospital, the surgery was designed to correct A-exotropia by lateral rectus' weaken and vertical offsets, and dissociated vertical deviation (DVD) by superior rectus muscles recession simultaneously.·RESULTS: A-exotropia and DVD of the patients vanished six months after the surgery. Both patients were clinically cured.·CONCLUSION: As the degree of horizontal and vertical strabismus was in the allowed range, complete examination and full assessment of the function of the four muscles were performed before operation, single operation can be considered in the treatment of Helveston syndrome.
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AIM: To survey the pathogenesis, clinical characteristics and surgical treatment for the correction of A-pattern exotropia.METHODS: The case history and surgical effect of 62 A-pattern exotropia in 1825 strabismus were studied. The superior oblique muscles weakening or the horizontal muscles procedures were performed in all patients according to the dysfunction of the superior oblique muscles, horizontal deviation, with or without binocular vision. Follow-up after surgery was 6-18months with mean duration of 9 months.RESULTS: A-pattern exotropia accounts for 3.4% of all strabismus. A-pattern exotropia accounts for 21.2% of A-V syndrome. After surgery, 52 cases got alignment, 56 cases gained A-sign correction and 54 cases recovered binocular vision.CONCLUSION: A-pattern exotropia is a common type in strabismus, its etiology is mainly oblique muscle dysfunction.Different surgical procedures should be selected according to overaction degrees of oblique muscle and binocular vision function, which can acquire the satisfied results.