1.Corneal biomechanical properties in different anterior chamber angle of glaucoma
Shaolin, DU ; Wenbin, HUANG ; Yichi, ZHANG ; Lam DENNIS
Chinese Journal of Experimental Ophthalmology 2016;34(10):930-935
Background Recent studies have demonstrated that glaucoma progression had great relationship with corneal biomechanical properties.However,there are not enough studies about corneal biomechanical properties in different types of glaucoma.Objective This study was to evaluate the corneal biomechanical properties in chronic primary angle-closure glaucoma (CPACG) and primary open angle glaucoma (POAG).Methods Prospective observational study was adopted.Sixty-eight cases (68 eyes) with CPACG and 69 POAG patients (69 eyes) from Zhongshan Ophthalmic Center were investigated by a novel technique named Corvis-ST which can measure corneal deformation.The Cronbach's αt coefficient and intraclass correlation coefficient (ICC) were used to evaluate the repeatability of the parameters from Corvis-ST.The differences of corneal biomechanical properties between POAG and CPACG were evaluated by independent-samples t test.Multiple regression analysis was used to assess the association between parameters of deformation response and clinical factors.This study protocol was approved by Ethic Committee of Zhongshan Ophthalmic Center and complied with Helsinki Declaration.Written informed consent was obtained from each patient prior to any medical examination.Results There were no statistic differences about age,sex and intraocular pressure (IOP) between CPACG and POAG patients (all at P>0.05).However,differences existed in the number of anti-glaucoma medications (t =-2.388,P =0.020).Measurements of central corneal thickness (CCT),deformation amplitude (DA),and peak distance (PD) demonstrated excellent repeatability (ICC≥ 0.8).There were no statistic differences about CCT,first applanation time/length/velocity (A1 T,A1 L,A1V),second applanation time/length/velocity (A2T,A2L,A2V),DA between CPACG and POAG patients (all at P> 0.05).The highest concavity time was shorter (t =2.920,P =0.005),PD was bigger (t =-2.453,P =0.017),and central curvature radius (CCR) was smaller (t =1.997,P =0.050) in POAG than those in the CPACG patients.DA,A1V,A2T and PD were negatively associated with IOP (r =-0.709,-0.531,-0.645,-0.554;all at P<0.001).However,A1T and A2V were positively associated with IOP (r=0.744,0.546;both at P<0.001).And CCR was positively associated with CCT (r =0.181,P =0.039).Conclusions It is useable to evaluate corneal biomechanical properties of glaucoma by Corvis ST.Under the same level of IOP,the corneal concavity of POAG is easier than that of CPACG,which indicates that cornea in POAG patients is more deformable.
2.A new eye syndrome of cataract,dwarf,polydactyly associated with genu valgum?
Xiu-Qin, ZHAO ; Xin, ZHAO ; Wen-Zhong, YANG ; Jie, YANG ; Dennis LAM
International Eye Science 2010;10(8):1469-1470
A male patient,39 years old,presented with symptoms of cataract,dwarf,progeria,polydactyly and genu valgum,after the extracapusular cataract extraction and intraocular lens implantation on both eyes,the visual acuity was improved and his fundus examination was normal.As the syndrome is different from any eye syndrome we have ever known,so it maybe a new one.
3.Updates on the surgical management of paediatric cataract with primary intraocular lens implantation.
Dorothy S P FAN ; Wilson W K YIP ; Christopher B O YU ; Srinivas K RAO ; Dennis S C LAM
Annals of the Academy of Medicine, Singapore 2006;35(8):564-570
With the advent of modern surgical techniques, paediatric cataract has become much more manageable. Intraocular lens (IOL) implantation is the standard of care for patients over the age of 2 years. The use of IOL in young infants is still controversial. In addition, there are still unresolved issues, such as the minimum age at which IOL can be safely implanted, IOL power selection and IOL power calculation. The current trends in the management of the above challenges are discussed. Although numerous reports on the prevention and management of posterior capsule opacification have been published, there are ongoing intensive debates and research. Long-term postoperative complications like glaucoma and rhegmatogenous retinal detachment are problems that cannot be overemphasised and these issues are also reviewed.
Cataract
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congenital
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Cataract Extraction
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adverse effects
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methods
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Child
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Child, Preschool
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Humans
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Infant
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Infant, Newborn
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Lens Implantation, Intraocular
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adverse effects
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methods
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Lenses, Intraocular
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Postoperative Complications
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prevention & control
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Refraction, Ocular