Objective To observe the location of peripapillary choroidal watershed zones relative to the optic disc in the different types of glaucoma. Methods A total of 98 patients (98 eyes) with glaucoma (glaucoma group) were enrolled in this study. The eyes included 34 eyes with primary open-angle glaucoma (POAG group), 33 eyes with normal tension glaucoma (NTG group) and 31 eyes with chronic angle closure glaucoma (CACG group). Thirty-seven fellow eyes of 37 patients with monocular blunt trauma were selected in this study as control group. The differences of age (t=1.197), sex (chi;2=3.548), average diopter (t=-1.644) between glaucoma group and control group were not statistically significant (P＞0.05). The differences of age (F=2.645), sex (F=1.984), average diopter (F=2.621), and visual fields mean defect (MD) (F=0.899) between different types of glaucoma were also not statistically significan(P＞0.05).Simultaneous indocyanine green angiography (ICGA) and fundus fluorescein angiography (FFA) were performed on all subjects. The watershed zones were classified into three types according to its location relative to the optic disc: in type Ⅰ, the watershed zone did not include the optic disc or could not be observed; in type Ⅱ, the watershed zone partially included the optic disc; in type Ⅲ, the watershed zone completely included the optic disc. The location of watershed zones relative to the optic disc in the different types of glaucoma was comparatively analyzed. The relationship between watershed zones, type and age, and MD were also analyzed by Pearson analysis method. Results The constituent ratio of type Ⅱ and Ⅲ watershed zones were 81.6% and 56.8% in glaucoma group and control group, respectively; with a statistically significant difference (chi;2=8.756,P＜0.003). The constituent ratios of type Ⅱ and Ⅲ watershed zones were 82.4%, 90.9%, 71.1% in POAG, NTG and CACG group, respectively. No significant differences were found between POAG and NTG group (chi;2=1.039), POAG and CACG group (chi;2=1.039, 1.166;P＞0.05). But there was significant difference between NTG and CACG group (chi;2=4.107,P＜0.05). Significant differences were found between POAG and control group, NTG and control group (chi;2=5.352, 10.141;P＜0.05). No significant difference was found between CACG and control group (chi;2=1.444,P＞0.05). There was no correlation between age and watershed zone type (r=0.114,P＞0.05). The watershed zones type of glaucoma group positively correlated with MD (r=0.354,P=0.000). Conclusion The peripapillary choroidal watershed zones in glaucoma patients include the optic disc more than in healthy eyes.
Objective To compare chordal transposition and chordal shortening in repairing anterior leaflet prolapse (ALP)， and explore the surgical indications as well as merits and demerits of these two techniques. 〖WTHZ〗Methods We retrospectively reviewed the data of 90 ALP patients recruited into Anzhen Hospital between March 1986 and March 2008, and classified them into chordal shortening group (n=23) and chordal transposition group (n=67). KaplanMeier survival curve and freedom from reoperation curve were established to compare the two groups. Univariate analysis and multivariate logistic analysis regression were used to identify independent risk factors for early death and late cardiac events. 〖WTHZ〗Results There were three perioperative deaths in chordal shortening group（13.0%）, and three deaths in chordal transposition group (4.4%), and the difference was not significant (χ2=2.019，P=0.155). The follow-up time ranged from 1 month to 18 yrs（7.70±5.41 yrs）. There were 5 late deaths, of which 3 were in chordal shortening group and 2 in chordal transposition group. The KaplanMeier survival curve showed that 5-year survival rate of chordal shortening group was significantly lower than chordal transposition group (70.00%±18.24% vs.98.00%±1.98%,χ2=12.50, P=0.000); And the KaplanMeier freedom from reoperation curve showed [CM(159mm]that 5-year reoperation rate of chordal shortening group was also significantly lower than chordal transposition group (83.30%±15.20% vs.96.10%±2.71%,χ2=10.27，P≤0.001). By the univariate analysis, we found that age＞55 yrs old, concomitant CABG procedure, New York Heart Association (NYHA) function class Ⅲ-Ⅳ, preoperative heart failure history, aortic clamping time＞90 min, and preoperative lefe ventricular ejection fraction (LVEF)＜45% were the risk factors for perioperative death and risk factors for late cardiac events included postoperative mitral regurgitation＞2+, chordal shortening technique, preoperative heart failure history, and aortic clamping time＞90 min. The multivariate logistic analysis regression showed that aortic clamping time＞90 min, concomitant CABG procedure, preoperative LVEF＜45% were the independent predictors for perioperative death, and NYHA class ⅢⅣ, chordalshortening technique and residual mitral regurgitation＞2+ were the independent predictors for the late cardiac events. Conclusion （1） There is no statistically difference between chordal transposition and chordal shortening in the perioperative survival rate. (2) Chordal transposition has a relative superiority to chordal shortening in terms of 5-year survival rate. (3) Chordal transposition has a higher mid and longterm rate of freedom from reoperation than chordal shortening. （4） Although chordal transposition has a lower incidence of reoperation and ahigher mid and longterm survival rate, the indication for it is restricted to less extensive ALP and patients with transferrable chord in the posterior leaflet. Chordal shortening is an independent risk factor for late events.
The paper extended the previous model by adding the effect of the permanent resident on the migrants. The numerical simulation indicated that the basic reproductive numbers should be less than one in permanent residents and migrants in order to eliminate disease from the population. Evaluation on the TB-Screen Strategy of Canada showed that the epidemic of TB was sensitive to the TB control strategies.