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眼轴对视网膜静脉阻塞的影响

Comparative Study between IOL Master and Contact Ultrasonic A-mode Scan in Measuring Anterior Chamber Depth and Axial Length in Cataract Patients and Normal Subjects

目的　通过比较白内障患者与正常人用两种方法测量的前房深度和眼轴长度值，观察IOL Master和接触式A型超声测量是否存在差别及其关联程度。 方法　选取2010年12月－2011年2月期间行白内障摘除加人工晶状体植入术的年龄相关性白内障患者及除屈光不正外没有其他眼部病变的志愿者共89例。分别用IOL Maste和A型超声测量54例（96只眼）白内障患者和35例（70只眼）正常者的前房深度（ACD）和眼轴长度（AL），应用配对t检验对每组两种方法测得的ACD及AL值进行比较，并应用Pearson相关分析比较两种方法的相关性。应用独立样本t检验比较白内障组和正常者组间两种方法测得的差值是否不同。 结果　白内障组A型超声和IOL Master测得的ACD值分别是（2.83 ± 0.34）、（3.05 ± 0.39） mm，AL值分别是（23.93 ± 2.46）、（24.27 ± 2.57） mm，差异均有统计学意义（P＜0.05）；正常者组A型超声和IOL Master测得的ACD值分别是（3.16 ± 0.36）、（3.43 ± 0.46） mm，AL值分别是（24.16 ± 1.61）、（24.49 ± 1.62） mm，差异均有统计学意义（P＜0.05）。两种测量方法的相关系数分别是rACD=0.823（P＜0.05）和rAL= 0.995（P＜0.05）。白内障组和正常者组两种方法测得的ACD差值分别是（0.23 ± 0.23）、（0.28 ± 0.30） mm；AL差值分别是（0.34 ± 0.27）、（0.33 ± 0.15） mm；两组间ACD和AL差值的比较，差异均无统计学意义（P=0.243，0.742）。 结论　不论是白内障组还是正常者组，用IOL Master测得的ACD及AL值均比A型超声测得的相应值高，但是两种方法测得的值高度相关。白内障组和正常者组用两种方法测得的差值相比无差别；在可测到ACD及AL值的情况下，两种测量方法的差值均不受晶状体密度的影响。

Effect of Axial Length and Gender on Maximum Corneal Curvature in Myopia Patients

【摘要】 目的 探讨影响近视患者中央角膜曲率(Kmean)及球镜屈光度的因素。方法 2008年3月—8月，使用角膜地形图测量157例(313眼)近视患者Kmean和角膜后表面高度。用A超测量眼轴长度和中央角膜厚度,验光测出球镜屈光度。分析可能影响Kmean及球镜屈光度的多个因素。其中男79例(157眼),女78例(156眼)；年龄18~45岁,中位年龄20岁。近视病程1～30年。近视球镜屈光度(-5.65±2.74)D。结果 眼轴长度、中央角膜厚度、角膜后表面高度、眼压、Kmean和球镜屈光度分别为:(26.00±1.04)mm、(540.50±31.02)μm、(26.96±6.05)μm、(17.05±2.48)mm Hg(1 mm Hg=0.133 kPa)、(43.30±1.46)D、(-5.65±2.27)D。Kmean的影响因素有:眼轴长度(βi=-0.411,P=0.000)、性别(βi=-0.278,P=0.000)、中央角膜厚度(βi=-0.180,P=0.000)[(Kmean(D)=63.9790.599×眼轴长度(mm)-0.813×性别(男=1,女=0)-0.009×中央角膜厚度(μm),R=0.583,F=25.804,P=0.000)]。球镜屈光度的影响因素有:眼轴长度(βi=-0.911,P=0.000)、Kmean(βi=-0.477,P=0.000)和性别(βi=0.183,P=0.000)[球镜屈光度(D)=76.585-1.990×眼轴长度(mm)-0.714×Kmean(D)+0.801×性别(男=1,女=0),R=0.837,F=117.295,P=0.000)]。结论 眼轴长度、中央角膜厚度和性别都对Kmean有影响,眼轴增长是近视的主要原因。

Research progress of gut microbiota in diabetic retinopathy

The concept of “Microbe-gut-eye axis” holds that metabolites of the gut microbiota are involved in the pathogenesis of various eye diseases. The composition and diversity of gut microbiota in diabetic retinopathy (DR) patients are significantly different from those in non-DR patients. Metabolites of the gut microbiota such as lipopolysaccharide, short-chain fatty acid, bile acids and branched-chain amino acid aggravate or attenuate the progression of DR by regulating the release of inflammatory cytokines, mitochondrial function, insulin sensitivity, immune response, and autophagy of retinal cells. Therefore, gut microbiota and their metabolites play a role in the occurrence and development of DR through multiple pathways. The participation of gut microbiota may open up a new way to prevent and treat DR in the future.

Research status and progress on the influence of high myopia on ocular structure and visual function

High myopia has a high genetic tendency, it not only shows in the excessive elongation of the axial length, but also lends to the formation and progression of various eye lesions, such as peripheral retinopathy, optic disc changes, posterior staphyloma, and myopic maculopathy, due to the mechanical stretching of the axial length to the ocular structure. In addition, high myopia increases the risk of several complications, such as glaucoma, cataract, and corneal disease. All these pathological changes will affect visual function and lead to irreversible vision impairment and blindness in the future. Therefore, it is important to pay attention to screening for optic disc abnormalities and posterior staphyloma, and regular monitor the changes of fundus, intraocular pressure, and lens. At the same time, high myopia has an impact on personal life such as study, psychology, sport, and work, and can reduce the quality of life as well as increase the cost of health care. The clinic should pay more attention to high myopia, prevent and control the development of high myopia from an early stage, in order to minimize its impact on ocular structure and visual function as well as its hazard to personal life and society.

Prevalence and risk factors of tessellated fundus in Tianjin Medical University students

ObjectiveTo investigate the prevalence and risk factors of tessellation fundus (TF) among Tianjin Medical University students with different refractive statuses. MethodsA cross-sectional study. From September to December 2019, 346 students from Tianjin Medical University were randomly selected and underwent slit-lamp examination, non-cycloplegic auto-refraction, subjective refraction, best-corrected visual acuity, ocular biometric measurement, and non-dilation fundus photography. The differences in the prevalence of TF in basic characteristics and ocular biometric parameters were compared. Based on the equivalent spherical (SE), refractive status was divided into the non-myopia group (SE＞－0.50 D) and the myopia group (SE≤－0.50 D). The myopia group was further divided into mild myopia group (－3.00 D＜SE≤－0.50 D), moderate myopia group (－6.00 D＜SE≤－3.00 D), and high myopia group (SE≤－6.00 D). According to the axis length (AL), the subjects were divided into AL＜24 mm group, 24-26 mm group, and ＞26 mm group. The logistic regression was used to analyze the risk factors affecting TF. Trend tests were performed for each risk factor and TF. ResultsOf the 346 subjects, 324 (93.6%, 324/346) were myopia, of whom 73 (21.1%, 73/346), 167 (48.3%, 167/346), and 84 (24.3%, 84/346) were mild myopia, moderate myopia, and high myopia, respectively; 22 (6.4%, 22/346) were non-myopia. There were 294 (85.0%, 294/346) students with TF in the macula, including 9 (40.91%, 9/22), 58 (79.45%, 58/73), 145 (86.83%, 145/167), and 82 (97.62%, 82/84) in non-myopia, low myopia, moderate myopia, and high myopia group, respectively; 52 (15.0%, 52/346) students were without TF in the macula. There were statistically significant gender differences (χ2=4.47), SE (t=6.29), AL (t=－8.29), anterior chamber depth (Z=－2.62), lens thickness (Z=－2.23), and average corneal radius (Z=－3.58) between students with and without TF in the macula (P＜0.05). Spherical equivalent and axial length were independent risk factors for TF and its severity (P≤0.001). With an increasing degree of myopia, and increasing axial length, the risk of TF increased (P for trend＜0.001). ConclusionsThe prevalence of TF is 85.0% among Tianjin Medical University students. TF is detected in the fundus of no myopia, mild myopia, moderate myopia and high myopia. The degree of myopia is higher, the AL is longer, the possibility of TF is higher.

Correlation between axial length and macular blood flow density and thickness in myopic eyes

ObjectiveTo observe the changes of retinal and choroidal blood flow density and thickness in macula of different myopic dioptre eyes, and to analyze the correlation between retinal and choroidal blood flow density and axial length (AL). MethodsA retrospective clinical study. From October 2022 to May 2023, 86 eyes of 56 myopic patients scheduled for refractive surgery in Hubei Clinical Center of Laser Ophthalmopathy were included into the study. According to the equivalent spherical specular degree (SE), 19, 21, 27 and 19 eyes of low myopia group (group A), moderate myopia group (group B), high myopia group (group C) and super high myopia group (group D) were observed. Optical coherence tomography angiography (OCTA) and AL measurement were performed in all patients. The diopter was expressed in SE. AL was measured by ultrasonic bio-meter. OCTA scanner was used to scan the macular region in the range of 3 mm × 3 mm. The software automatically divided the macular region into two concentric circles with the fovea as the center, which were 1 mm in diameter respectively, the paracentric fovea of 1-3 mm was divided into 5 regions: superior, nasal, inferior and temporal. The superficial capillary plexus (SCP), deep capillary plexus (DCP), choroidal capillary plexus (CC), choroidal blood flow density, retinal and choroidal thickness were measured. The correlation between AL and blood flow density and thickness was analyzed by Pearson correlation analysis. ResultsThere was no significant difference in SCP blood density and DCP blood density in the fovea in groups A, B, C and D (P＞0.05) .There were significant differences in DCP flow density among superior, nasal, inferior and temporal areas (P＜0.05), the difference was significant (P＜0.05). There was no significant difference in the fovea area between the four groups (P＞0.05), but there was significant difference in the superior, nasal, inferior and temporal areas (P＜0.05). Different macular regions: there were statistically significant among group A, group B, and group C, group D (P＜0.05). Results of correlation analysis, AL was negatively correlated with DCP blood flow density (r=－0.504, －0.500, －0.460, －0.465), retinal thickness (r=－0.348, －0.338, －0.312, －0.230), macular Subarea CC (r=－0.633, －0.666, －0.667, －0.710, －6.82), choroidal layer (r=－0.635, －0.687, －0.659, －0.703, －0.680) and choroidal thickness (r=－0.665, －0.605, －0.656, －0.648, －0.643) (P＜0.05). ConclusionsAL is negatively correlated with DCP, CC, CDF, retinal and choroidal thickness in the eyes with myopia. SCP, DCP and retinal thickness in fovea did not change significantly, and temporal choroidal thickness changed earlier than other areas.