The Measurements Of Lens Thickness, Anterior Chamber Depth In Normal Subjects And Discussions Of Influencing Factors

Objective Measuring lens thickness(LT), anterior chamber depth(ACD) in normal subjects,and caculating the values of r ACD( ACD/AL), r LT( LT/AL), r[(ACD+LT)]/LT simultaneously.Then discuss the impacts with age gender, axial length(AL) changes, and approach the correlations and multiple correlations of ACD,LT to age and AL also. Collecting the patients of ARC(Age-related cataract,ARC) as the study objects, further analyse the changes of the paremeters above among pure cortical cataract, pure nuclear cataract and pure PSC(posterior subcapsular cataract).Methods Observation case series. the measurement was carried in 618 people1236 eyes in total(male544eyes, female692eyes) of normal subjects aged over 10 years by Lenstar LS900, including AL, ACD, LT, then calculate the values of r ACD, r LT, r. Dividing age into six groups: 10-20 years(group A),21-30years(group B),31-40years(group C),41-50years(group D), 51-60years(group E)and over 61years(group F), then AL into four groups also: short AL group under 22.00mm(groupⅠ), normal AL group22.00-23.99mm(groupⅡ), long AL group 24.00-25.99mm(group Ⅲ)and Ex-long Al group over 26.00mm(group Ⅳ), and then compariring the parameters in different factors.Continuous collection of the ARC patients in cataract department who are planing for cataract surgeries. Mydrin P(Compound Tropicamide Eye Drops) to the patients after admissions to hospital. when the pupil diameter has been dilated to6-8mm, checking under the slim-lamp. Selecting the pure cortical cataract, pure nuclear cataract and PSC as study objects 187eyes(male 77 eyes, female 110 eyes).Taking photos with the slim-lamp anterior segment camera and opacity classification according to LOCS Ⅲ.Measuring AL, ACD, LT and caculating r ACD, r LT, r with Lenstar LS900 eventually. Camparing the changing characters of the parameters among the three cataract types. tatistical analysis was performed with spss 17.0.Results ACD, LT in normal male subjects are( 2.85±0.41) mm,( 4.07±0.51) mm,respectively. In female subjects are(2.70±0.40)mm,(4.18±0.46)mm, respectively. AL,ACD, LT, r ACD, r LT, r were no significant differences in both eyes(t=-0.030,-0.286,0.035,-0.192,-0.176, P >0.05), but significant differences in gender, AL and age(t=6.667,-3.941, 5.496,-5.032,-2.807; F=83.173, 34.781, 11.422, 136.072, 198.695;F=15.539, 114.951, 17.887, 103.908, 45.151, P <0.001).After the correlation analysis and multiple linear regression analysis, we think in males, regression coefficients of ACD with age and AL are-0.011 and 0.131 respectively, regression coefficients of LT with age and AL are 0.023 and-0.079 respectively. In females, regression coefficients of ACD with age and AL are-0.011 and 0.119 respectively, regression coefficients of LT with age and AL are 0.021 and-0.045 respectively.Constituent ratios of three ARC types between male and female are not all the same, and the difference is significant(χ2=13.09,P<0.05).Whatever in male or female,surgery age, LT, r LT are all significant differences among the three groups(F=15.890, 11.586, 6.949, F = 26.928, 20.400, 3.193, P<0.05),But not AL and r( F = 2.036, 0.464, F=1.620, 2.643, P>0.05).The results of r ACD, ACD are significant difference in different genda.In male, ACD has no significant difference between cortical cataract and PSC( P>0.05),but other groups are significant differences( P<0.05) and r ACD has significant differences among all groups( F=11.863,P<0.05);In female, ACD has significant differences among all groups(F =4.132, P<0.05).r ACD has no significant difference between cortical cataract and nuclear cataract(P>0.05),but other groups are significant differences(P<0.05)Conclusions1. In normal subjects, male subjects have thinner LT, deeper ACD, and the both are no significant differences in two eyes;2. With the longer AL, LT is thinner and ACD is deeper; In males,with AL increasing1 mm,LT is thinner 0.079 mm and ACD is deeper 0.131mm; In females,with AL increasing 1mm,LT is thinner 0.045 mm and ACD is deeper 0.119mm;3. As age increasing, LT is thicker and ACD is deeper; In males,with age increasing10 years,LT is thicker 0.23 mm and ACD decreases 0.11mm; In females,with age increasing 10 years, LT is thicker 0.21 mm and ACD decreases 0.11mm;4. Constituent ratios of three ARC types are not all the same,pure nuclear cataract isthe most common both in male and female, pure cortical cataract and pure PSC(posterior subcapsular cataract)are the rarest in male and female respectively.5. Whatever in male or female, AL, are both have no significant differences in three ARC types.LT is thickest in nuclear cataract and thinnest in PSC.6. The same as normal people, ACD becomes shallower as the LT is thicker.In female,ACD, r ACD are smallest in cortical cataract.