Comparison of peripapillary and macular choroidal thickness and ganglion cell complex thickness in glaucomatous and healthy eyes

AIM: To assess choroidal thickness(CT) and its association with ganglion cell-inner plexiform layer thickness(GCIPLT) and retinal nerve fiber layer thickness(RNFLT) in open angle glaucoma(OAG) comparing with preperimetric glaucoma(PPG) and normal eyes.METHODS: Totally 55 eyes of OAG, 40 eyes of PPG, and 40 eyes of age-matched normal eyes were studied. Peripapillary CT(PCT), macular CT(MCT), RNFLT, and GCIPLT were evaluated. Relationship between the CT with RNFLT and GCIPLT were studied. The correlation between CT and confounding variables as gender, age, intraocular pressure, and visual field mean deviation were analyzed. RESULTS: Mean PCT were 113.6±39.1 μm in OAG, 116.3±42.7 μm in PPG, and 148.9±41.7 μm in normal eyes. PCT and MCT was thinner in OAG compared to healthy eyes. There was a significant correlation for PCT and mean RNFLT in 1, 2, 6, and 7 clock hours of OAG eyes. The difference in PCT remained after adjusting for axial length, age, and disc area(P=0.003). No significant correlation was shown between MCT and mean GCIPLT in all eyes.CONCLUSION: PCT is thinner in OAG and PPG compared with healthy eyes. The correlation of RNFLT and PCT found in OAG and PPG is not revealed in normal eyes.

Factors associated with axial length elongation in high myopia in adults

AIM:To investigate the association of axial length(AL)and ocular factors on AL elongation.METHODS:A retrospective chart review of patients who underwent two or more AL examinations for more than two years.Totally 4 groups were divided according to initial AL(<24 mm,24-26 mm,26-28 mm,≥28 mm).Initial fundus photograph was used to find risk factors associated AL elongation.RESULTS:The mean age of the patients was 47.21±7.79 y.AL remained almost unchanged in the groups with AL<24 mm and 24≤AL<26 mm.On the contrary,AL increased by 0.011 mm/y in the group with 26≤AL<28 mm and 0.035 mm/y in the group with AL≥28 mm(P<0.001).In high myopia,AL elongation increased in eye with longer AL(r=0.003,P=0.024),female gender(r=0.014,P=0.019),eye with larger peripapillary chorioretinal atrophic area(r=0.002,P=0.019),and smaller vascular arcade angle(r=-0.004,P=0.006).The risk of elongation 0.03 mm/y in high myopia was increased in female gender(P=0.040),and gradually increased in eye with large peripapillary chorioretinal atrophy area(P<0.01).CONCLUSION:AL elongate significantly in the eye with longer AL,female gender,and the eye with larger atrophic area and smaller arcade angle on fundus photography.

Enhancement of ballistic performance enabled by transformation-induced plasticity in high-strength bainitic steel

High-strength bainitic steels have created a lot of interest in recent times because of their excellent combination of strength,ductility,toughness,and high ballistic mass efficiency.Bainitic steels have great potential in the fabrication of steel armor plates.Although various approaches and methods have been conducted to utilize the retained austenite(RA)in the bainitic matrix to control mechanical properties,very few attempts have been conducted to improve ballistic performance utilizing transformationinduced plasticity(TRIP)mechanism.In this study,high-strength bainitic steels were designed by controlling the time of austempering process to have various volume fractions and stability of RA while maintaining high hardness.The dynamic compressive and ballistic impact tests were conducted,and the relation between the effects of TRIP on ballistic performance and the adiabatic shear band(ASB)formation was analyzed.Our results show for the first time that an active TRIP mechanism achieved from a large quantity of metastable RA can significantly enhance the ballistic performance of high-strength bainitic steels because of the improved resistance to ASB formation.Thus,the ballistic performance can be effectively improved by a very short austempering time,which suggests that the utilization of active TRIP behavior via tuning RA acts as a primary mechanism for significantly enhancing the ballistic performance of high-strength bainitic steels.