The two-step hydro-bulge forming technique was proposed to manufacture the ellipsoidal shell with the length ratio of the long axis to the short axis larger than 1.4. A central tube was introduced into the first step ...The two-step hydro-bulge forming technique was proposed to manufacture the ellipsoidal shell with the length ratio of the long axis to the short axis larger than 1.4. A central tube was introduced into the first step of the hydro-bulge forming process to constrain the over growth of the short axis during bulging,and then the central tube was replaced with two polar plates in the second step of the hydro-bulge forming process to manufacture an integral ellipsoidal shell. It is shown that the central tube restricts the growth of the short axis and simultaneously reduces the shrunk tendency of the long axis. The wrinkling occurs due to the latitudinal compressive stress at the equator at the early stage of hydro-bulge forming. However,with the increase of internal pressure,the compressive stress areas gradually decrease and finally the tensile latitudinal stress occupies approximately the whole shell,thus the wrinkles are eliminated. A sound ellipsoidal shell with the axis length ratio of 1.8 is obtained after two-step hydro bulging.展开更多
AIM:To analyze ocular parameters and refractive status in children aged 3-12y and to explore differences in these parameters across age groups with identical refractive status for studying refractive progression.METHO...AIM:To analyze ocular parameters and refractive status in children aged 3-12y and to explore differences in these parameters across age groups with identical refractive status for studying refractive progression.METHODS:Demographic characteristics,cycloplegic refraction data,and ocular parameters of the participants were collected.Changes in ocular parameters were described according to different age groups.After adjusting for refractive factors,the relationship between age and ocular parameters was explored.Standard regression coefficients(β)obtained from multiple linear regressions were used to compare the magnitude of the effect of age on the parameters and ocular components on refractive power.RESULTS:Data were collected from the right eyes of 1504 participants.Lens thickness(LT)decreased with age,whereas the axial length(AL)and anterior chamber depth(ACD)increased.In the high-hyperopia group,changes in age were only associated with AL and LT.In the low-myopia group,the increase in age was also associated with corneal astigmatism.In the overall model,theβvalue for LT was the highest at 0.41,whereasβfor ACD and AL was significant in all groups except for the high-hyperopia group.Theβvalue of the LT on refractive power in children was slightly greater in the low age group than in the high age group.CONCLUSION:Among children with the same refractive status,the older the age,the longer the axis length and the thinner the lens.The lens affected refractive power in children in the younger age group more than in the older age group.The ocular parameter most affected by age was LT.展开更多
AIM:To evaluate refraction and ocular biological characteristics in children with unilateral congenital ptosis.METHODS:In this cross-sectional study,200 Chinese children(3-15y)with unilateral congenital ptosis were ev...AIM:To evaluate refraction and ocular biological characteristics in children with unilateral congenital ptosis.METHODS:In this cross-sectional study,200 Chinese children(3-15y)with unilateral congenital ptosis were evaluated.Cycloplegic refraction and ocular biological measurements were taken from Oct.2020 to Aug.2022.RESULTS:In patients with congenital ptosis,the prevalence of with-the-rule astigmatism and oblique astigmatism was significantly high.The cornea was flatter in ptotic eyes[K1(42.37±1.62 vs 42.78±1.51 D),K2(43.8±1.86 vs 44.2±1.64 D),corneal power(Km;43.09±1.68 vs 43.49±1.53 D),all P<0.001].Axial length(AL)was longer in ptotic eyes(22.55 vs 22.51 mm,P=0.012).The white-towhite(WTW)was significantly smaller in ptotic eyes(11.49 vs 11.65 mm,P<0.001).The central corneal thickness(CCT)was greater in ptotic eyes(553.50 vs 545.00μm,P<0.001).No significant differences were found in anterior chamber depth(AD),lens thickness(LT)and vitreous thickness(VT)between ptotic and fellow eyes(P>0.05).In addition,the incidence of amblyopia in ptosis eyes was 32.0%,which was significantly higher than that in the normal population.CONCLUSION:Ptotic eyes have longer AL,flatter,thicker and smaller corneas than fellow eyes.The congenital ptosis increases the risk of amblyopia.The results suggest that regular examinations of refractive status and ocular biological parameters such as AL,are essential for children with unilateral congenital ptosis.展开更多
基金Sponsored by the National Natural Science Foundation of China (Grant No. 59975022 and 50275034)
文摘The two-step hydro-bulge forming technique was proposed to manufacture the ellipsoidal shell with the length ratio of the long axis to the short axis larger than 1.4. A central tube was introduced into the first step of the hydro-bulge forming process to constrain the over growth of the short axis during bulging,and then the central tube was replaced with two polar plates in the second step of the hydro-bulge forming process to manufacture an integral ellipsoidal shell. It is shown that the central tube restricts the growth of the short axis and simultaneously reduces the shrunk tendency of the long axis. The wrinkling occurs due to the latitudinal compressive stress at the equator at the early stage of hydro-bulge forming. However,with the increase of internal pressure,the compressive stress areas gradually decrease and finally the tensile latitudinal stress occupies approximately the whole shell,thus the wrinkles are eliminated. A sound ellipsoidal shell with the axis length ratio of 1.8 is obtained after two-step hydro bulging.
基金Supported by the National Natural Science Foundation of China(No.82171093).
文摘AIM:To analyze ocular parameters and refractive status in children aged 3-12y and to explore differences in these parameters across age groups with identical refractive status for studying refractive progression.METHODS:Demographic characteristics,cycloplegic refraction data,and ocular parameters of the participants were collected.Changes in ocular parameters were described according to different age groups.After adjusting for refractive factors,the relationship between age and ocular parameters was explored.Standard regression coefficients(β)obtained from multiple linear regressions were used to compare the magnitude of the effect of age on the parameters and ocular components on refractive power.RESULTS:Data were collected from the right eyes of 1504 participants.Lens thickness(LT)decreased with age,whereas the axial length(AL)and anterior chamber depth(ACD)increased.In the high-hyperopia group,changes in age were only associated with AL and LT.In the low-myopia group,the increase in age was also associated with corneal astigmatism.In the overall model,theβvalue for LT was the highest at 0.41,whereasβfor ACD and AL was significant in all groups except for the high-hyperopia group.Theβvalue of the LT on refractive power in children was slightly greater in the low age group than in the high age group.CONCLUSION:Among children with the same refractive status,the older the age,the longer the axis length and the thinner the lens.The lens affected refractive power in children in the younger age group more than in the older age group.The ocular parameter most affected by age was LT.
基金Supported by the Fundamental Research Funds of the State Key Laboratory of Ophthalmology(No.30306020240020319)Municipal School(Hospital)Jointly Fund Project of Guang Zhou(No.SL2024A03J00492)+2 种基金Teaching Reform Projects in 2023 by the Steering Committee for the Construction of New Medical Departments in Guangdong ProvinceGuangdong Medical Research Foundation(No.A2021369)Natural Science Foundation of Guangdong Province,China(No.2023A1515011652).
文摘AIM:To evaluate refraction and ocular biological characteristics in children with unilateral congenital ptosis.METHODS:In this cross-sectional study,200 Chinese children(3-15y)with unilateral congenital ptosis were evaluated.Cycloplegic refraction and ocular biological measurements were taken from Oct.2020 to Aug.2022.RESULTS:In patients with congenital ptosis,the prevalence of with-the-rule astigmatism and oblique astigmatism was significantly high.The cornea was flatter in ptotic eyes[K1(42.37±1.62 vs 42.78±1.51 D),K2(43.8±1.86 vs 44.2±1.64 D),corneal power(Km;43.09±1.68 vs 43.49±1.53 D),all P<0.001].Axial length(AL)was longer in ptotic eyes(22.55 vs 22.51 mm,P=0.012).The white-towhite(WTW)was significantly smaller in ptotic eyes(11.49 vs 11.65 mm,P<0.001).The central corneal thickness(CCT)was greater in ptotic eyes(553.50 vs 545.00μm,P<0.001).No significant differences were found in anterior chamber depth(AD),lens thickness(LT)and vitreous thickness(VT)between ptotic and fellow eyes(P>0.05).In addition,the incidence of amblyopia in ptosis eyes was 32.0%,which was significantly higher than that in the normal population.CONCLUSION:Ptotic eyes have longer AL,flatter,thicker and smaller corneas than fellow eyes.The congenital ptosis increases the risk of amblyopia.The results suggest that regular examinations of refractive status and ocular biological parameters such as AL,are essential for children with unilateral congenital ptosis.
