Distribution Of Astigmatism And Analysis Of Aspheric Corneal Before Cataract Surgery For Central Plains Of Age-related Cataract Crowd

Background and objectiveAge-related cataract (age-related cataract) is the world’s common blinding eyedisease. With the progress of modern living standards and medical technologies, theaverage life expectancy of our population is constantly extended. Thus, theprevalence of age-related cataract is also increasing every year. Currently, thetreatment for cataract surgery is still the main drugs used only for cataract onset ofdelaying the development of the course, but its efficacy has not yet been recognizedby ophthalmologists. With the improvement of people’s living standards of moderncataract surgery continue to improve and perfect the technology and equipment, thevisual quality of cataract surgery patients increasingly higher demands. Therefore,cataract surgery has been attributed to refractive surgery. How to improve cataractsurgery intraocular lens is a new visual quality objectives pursued by contemporary ophthalmologists. The main factors affecting the visual quality of cataract surgery isan aberration. Into low-order aberrations aberration and higher order aberrations.Mainly low-order aberrations refractive errors, namely hyperopia, myopia andastigmatism; while the higher-order aberrations are mainly spherical aberration of thecornea. Currently, for cataract patients implanted IOL, can be accurate biometrics, abetter solution preoperative myopia and hyperopia. IOL cataract patients affected eyeimage quality is mainly due to the refractive state of the cornea and cornealasphericity. Therefore, only fully understood before cataract surgery in patients withexisting state and aspheric corneal refractive characteristics of the cornea that cornealQ value, in order to at the time of cataract surgery, for different patient, reasonable,individual style and design of cataract surgery select the appropriate aspheric IOL,astigmatism and spherical aberration problem solved before a planned surgery corneaexists for patients to have better visual quality foundation.Currently, studies have reported before for age-related cataract surgery andcorneal refractive aspheric analysis of the state mainly in southern China. CentralPlains region studies have not been reported. Therefore, this issue is mainly forscreening analysis of the Central Plains region before cataract surgery in patients withage-related corneal refractive status and characteristics of non-spherical and provideexperimental evidence cataract surgery and intraocular lens design method of choice.Materials and MethodsThis topic filter objects from age-related cataract patients from November2012to February2014to the First Affiliated Hospital of Zhengzhou University hospital.Case Inclusion criteria: patients aged40to90years of cataract crowd, preoperativeaxial length (axial length, AL) between the22~26mm, with normal cognitivebehavior, good adherence, patients can palpebral fully open big, transparent corneaand tear film integrity. Case exclusion criteria: impact of preoperative cornealrefractive state of the disease, such as trauma, glaucoma and ocular symptoms,corneal opacity degeneration, pterygium, keratoconus, dry eye[1-7], etc., and cornealflexor patients optical surgery and intraocular surgery history. All patients before cataract surgery, have carried out a system to improve thepreoperative examination, including visual acuity, subjective refraction, slit lamp tocheck the anterior segment, and fundus examination, corneal endothelial cell countswere measured visual electrophysiology of the eye B-measurement and eye pressurechecked; Orbscan-Ⅱ anterior segment analyzer and IOLMaster biometry detection.For corneal refractive status and characteristics of non-spherical screening, mainlyOrbscan-Ⅱanterior segment analyzer based on measured data, and the results of acomprehensive analysis to determine the combination of refraction and keratometryIOLMaster biometry obtained values. Record the corneal curvature, axialastigmatism, astigmatism and corneal Q values. And statistical analysis of data frommore than age, gender and geographic (urban and rural) of these three aspects, andanalyze the correlation between corneal refractive status and non-spherical natureand value of these three factors.Application of SPSS16statistical software package for data analysis, calculatethe mean and standard deviation. By KS goodness to test whether a variable isnormally distributed (α=0.05, P> Pα, a statistically significant difference); usingPearson’s correlation coefficient to assess the correlation between two variables arenormally distributed between using the Spearman rank correlation coefficient toassess the correlation between the non-compliance with incomplete bivariate normaldistribution between (|r|≈1, the greater the correlation, r>0, a positive correlation,r <0, negative correlation;|r|≈0, no significant correlation between P> P|. r|, astatistically significant difference).ResultInclusion criteria were screened according to age-related cataract patients with404cases (558eyes), aged40to86years, with an average of (65.54±10.91) yearsof age. Among them,40to49years42patients (54eyes),50to59years74patients(102eyes),60to69years112patients (146eyes),70to79years of152patients(222eyes),80to86years24patients (34eyes). Preoperative keratometry was40.25~52.30D, average (45.12±2.05) D, showed a normal distribution (P=0.33); difference between its value and the age, gender and geographic without a significantcorrelation. Preoperative corneal astigmatism was0.1~4.5D, average (1.04±0.77)D, showed a non-normal distribution (P=0.00). Where there is greater than or equal1.0D244eyes, accounting for43.73%; rule astigmatism accounted for38.71%,accounting for43.73percent against the rule astigmatism, oblique astigmatismaccounted for17.56%, and with age, astigmatism distribution by Shun ruleastigmatism against the rule astigmatism to change; astigmatism was positivelycorrelated with age (r=0.827, P=0.003), gender and regional differences and nosignificant correlation. Preoperative corneal Q value of-0.75to+0.6, mean (-0.21±2.23), showed a normal distribution; difference between its value and the age, genderand regional no significant correlation. Curvature of the cornea, no significantcorrelation between the degree of astigmatism and corneal Q values of the three.Conclusion1Distribution of age-related corneal astigmatism before cataract surgery populationshowed a non-normal distribution; grow older, astigmatism distribution transitionfrom cis to rule astigmatism against the rule astigmatism; approximately43.73%ofthe patients required surgery which simultaneously correction of astigmatism; cornealastigmatism was positively correlated with age, no correlation between gender andregional differences in the.2Distribution of age-related cataracts before the crowd showed corneal curvaturenormal distribution, the value of the corneal curvature no significant correlation withage, gender, and regional and other differences.3Distribution of age-related cataract crowd before corneal Q values were normaldistribution, corneal Q values are mostly negative, and its value was no significantcorrelation with age, gender, and regional and other differences.4Age-related cataract astigmatism crowd preoperative keratometry and corneal Qvalue, there was no significant correlation between the three.