Corneal changes in type II diabetes mellitus in Malaysia

AIM: To compare corneal endothelial structure and central corneal thickness (CCT) between type II diabetics and non-diabetic control patients. To look for correlations between diabetic status and corneal findings. METHODS: Hospital-based, observational study. 200 eyes (from 100 type II diabetic patients and 100 controls) were included. Specular microscopy and pachymetry were used to measure endothelial cell density, size, coefficient of variation in cell area, hexagonality as well as corneal thickness. Independent t-tests were used to compare variables between diabetics and controls. Pearson correlation tests were used to evaluate correlations between corneal findings and diabetic status such as duration of diabetes, haemoglobin A1c (HbA1c) level and severity of diabetic retinopathy. RESULTS: Endothelial cell density in the diabetic group (2541.6±516.4 cells/mm2) was significantly lower than that in the control group (2660.1±515.5 cells/mm2, P <0.05). The average size of endothelial cells, standard deviation (SD) of cell size and coefficient of variation (CV) of cell area were all significantly higher in diabetics. Hexagonality was significantly lower in diabetics (41.1%±19.6%) compared to non- diabetics (45.2%±20.6%). CCT was higher in diabetics but not significant (P >0.05). Duration of diabetes, HbA1c level and severity of diabetic retinopathy were not significantly correlated with corneal endothelial findings. CONCLUSION: Type II diabetes causes a significant alteration in the state of the cornea including reduction in endothelial cell density and increased pleomorphism and polymegathism. Central corneal thickness is unaffected.     

The corneal endothelium and thickness in type II diabetes mellitus

PURPOSE: To compare the endothelial structure and thickness of the cornea in diabetic and nondiabetic patients, and to evaluate the systemic and ocular factors that contribute to the damage of endothelial cells in diabetic patients. METHODS: The corneal endothelial structure and central corneal thickness (CCT) were investigated in 99 type II diabetic patients (99 eyes) and in 97 nondiabetic patients (97 eyes). The endothelial structure was examined for cell density, coefficient of variation of cell area, and percentage of hexagonal cells. The correlation between CCT and the grade of diabetic retinopathy was evaluated. Multivariate regression analysis was performed to assess systemic factors (patient age, sex, duration of diabetes mellitus, hemoglobin A(1c) value, glucose in urine, blood urea nitrogen value, and creatine value) and ocular factors (grade of diabetic retinopathy and history of photocoagulation) related to endothelial cell density. RESULTS: The endothelial cell density was decreased and the coefficient of variation of cell area was increased in diabetic patients (P <.05). However, the percentage of hexagonal cells and CCT in diabetic patients was not significantly different from that in nondiabetic patients. CCT was similar regardless of the stage of diabetic retinopathy. Multivariate regression analysis indicated that none of the systemic or ocular factors was significantly correlated with the endothelial cell density. CONCLUSIONS: Corneal endothelial cell structure was damaged, but CCT was not increased in type II diabetic patients. There were no systemic or ocular factors at any one point to induce corneal endothelial damage.     

Corneal endothelial morphology and central corneal thickness in type 2 diabetes mellitus patients

Purpose:This study aimed to examine the corneal endothelial morphology and thickness in patients with Type 2 diabetes mellitus (T2DM) and compare them with age and sex-matched nondiabetic controls.Methods:This hospital-based cross-sectional observational study was conducted in the ophthalmology department of a tertiary hospital consisting of 262 patients (131 with T2DM as cases and 131 without diabetes who served as controls). All patients underwent a comprehensive ocular examination including visual acuity, slit-lamp biomicroscopy, intraocular pressure measurement. Central corneal thickness (CCT), endothelial cell density (ECD), coefficient of variance (CV), and percentage of hexagonal cells (HEX) were compared between the cases and controls. Predictors of corneal endothelial dysfunctions were analyzed. Data analysis was done by Statistical Package for the Social Sciences (SPSS) version 17.0. Chi-square test, Fisher’s exact test, and Spearman’s rho correlation analysis were used as appropriate.Results:Patients with T2DM showed poorer visual acuity and higher intraocular pressure. As compared to controls, patients with T2DM had thicker CCT, lesser ECD, decreased HEX, and higher CV but the differences were statistically nonsignificant. HbA1c levels showed a significant positive correlation with CCT and CV and a negative correlation with ECD. Macroalbuminuria and higher albumin creatinine ratio was associated with an increase in CV in patients with T2DM.Conclusion:Our study showed that poorly controlled patients with T2DM and those with macroalbuminuria have corneal endothelial abnormalities.     

2型糖尿病患者血糖控制水平与角膜神经损伤的相关性

目的　探讨2型糖尿病患者血糖控制水平与角膜神经损伤的相关性。方法　回顾性病例研究。选择2019年3月至2021年6月我院收治的2型糖尿病患者468例,根据糖化血红蛋白（HbA1c）水平将其分为A组（HbA1c＜7%,152例）、B组（7%≤HbA1c＜9%,187例）、C组（HbA1c≥9%,129例）,另外选择20位自愿者为对照组。所有受试者均接受角膜共聚焦显微镜（CCM）检查,并完善实验室检查。利用Pearson相关分析探讨受试者临床指标与CCM参数的相关性,多重线性回归分析探索影响2型糖尿病患者角膜基底膜下神经密度的相关因素。结果　C组患者角膜基底膜下神经密度、主干神经长度、主干神经数量均低于B组、A组和对照组（均为P<0.05）,主干神经弯曲均大于B组、A组和对照组（均为P<0.05）。B组患者角膜基底膜下神经密度、主干神经长度、主干神经数量均低于A组（均为P<0.05）,A组患者角膜基底膜下神经密度、主干神经长度、主干神经数量均低于对照组（均为P<0.05）。相关性分析结果显示:年龄、2型糖尿病病程、HbA1c、空腹血糖（FPG）、餐后2 h血糖（2hPG）、尿素氮（BUN）、血肌酐（Scr）与角膜基底膜下神经密度均呈负相关（均为P<0.05）,2型糖尿病病程、HbA1c、FPG与角膜基底膜下主干神经长度和数量均呈负相关（均为P<0.05）。多重线性回归分析结果显示:年龄、2型糖尿病病程、HbA1c、BUN与 2型糖尿病患者角膜基底膜下神经密度均有相关性（均为P<0.05）。结论　2型糖尿病患者血糖控制不良可能与角膜神经损伤有关。     

糖尿病性白内障术后角膜内皮细胞的变化

目的研究糖尿病性白内障患者及合并高血压的糖尿病性白内障患者超声乳化术后角膜内皮细胞数量及形态学变化情况。方法随机选取行白内障手术的单纯老年性白内障患者40例(48眼)为对照组,糖尿病性白内障患者36例(42眼)为糖尿病组,以及合并高血压的糖尿病性白内障患者34例(44眼)为糖尿病合并高血压组;采用角膜内皮计对术前及术后1周、1个月角膜中央区的角膜内皮细胞进行计数,并观察角膜内皮细胞密度、细胞面积、六角形细胞百分比、变异系数变化情况。结果术前糖尿病组与对照组相比,六角形细胞比例均下降,细胞变异系数均增加,差异均有统计学意义(均为P<0.05),糖尿病合并高血压组六角形细胞比例进一步下降,变异系数进一步增加,与糖尿病组相比,差异亦均有统计学意义(均为P<0.05)。术后1周,糖尿病组角膜内皮细胞密度、细胞面积、六角形细胞比例、细胞变异系数分别为(2458.00±349.23)mm-2、(390.65±118.55)μm2、(46.18±9.24)%以及45.01±6.13,糖尿病合并高血压组分别为(2251.83±368.41)mm-2、(390.12±231.44)μm2、(42.73±8.75)%以及48.81±5.04,二者相比,六角形细胞比例和细胞变异系数间差异有统计学意义(均为P<0.05);术后1个月,糖尿病组和糖尿病合并高血压组六角形细胞比例均进一步降低,分别为(40.72±4.60)%和(36.91±7.35)%,细胞变异系数进一步增加,分别为50.55±9.25和55.25±9.83,两组相比差异均有统计学意义(均为P<0.05)。结论糖尿病性白内障患者角膜内皮细胞状况较单纯老年性白内障患者差;糖尿病性白内障患者以及合并高血压的糖尿病性白内障患者角膜内皮在超声乳化术中都更易受到损害。     

Effect of diabetes mellitus on corneal biomechanics and measurement of intraocular pressure

Purpose: To determine whether corneal hysteresis (CH) and corneal resistance factor (CRF) are altered in diabetes and whether these parameters are related to HbA1c. Methods: One randomly chosen eye of 35 healthy subjects and 31 patients with diabetes was examined. Patients with diabetes were divided into group 1 with HbA1c <7% (n?=?14) and group 2 with HbA1c ≥7% (n?=?17). CH and CRF were measured using ocular response analyzer (ORA); central corneal thickness (CCT) using ultrasound pachymetry; increased intraocular pressure (IOP) using Goldmann tonometer (IOP(GAT) ), Pascal dynamic contour tonometer (IOP(pasc) ), and ORA (IOP(cc) ). As CH and CRF are dependent on IOP and CCT, they were adjusted for IOP and CCT resulting in CH(corr) and CRF(corr.) Results: Mean HbA1c was 5.44?±?0.46% in healthy subjects, 6.00?±?0.78% in diabetic group 1, 8.58?±?2.44% in group 2. CH(corr) (p?=?0.071) and CRF(corr) (p?=?0.067) were not statistically significantly different between healthy subjects and diabetic group 1, but significantly lower in healthy subjects compared to diabetic group 2 [CH(corr) (p?=?0.031), CRF(corr) (p?=?0.029)]. IOP(pasc) (p?=?0.012), IOP(GAT) (p?=?0.032) and HbA1c (p?=?0.0001) were statistically significantly different between healthy subjects and all patients with diabetes (groups 1?+?2), but not age, sex and CCT. Over all patients with diabetes, CH(corr) (p?=?0.012, R(2) =?0.197) and CRF(corr) (p?=?0.008, R(2) =?0.217) were correlated to HbA1c but not in healthy subjects [CH(corr) (p?=?0.931, R(2) =?0.0001), CRF(corr) (p?=?0.837, R(2) =?0.001)]. Conclusion: In poorly controlled diabetics, CH(corr) and CRF(corr) are significantly higher compared with those of the healthy subjects and patients with well-controlled diabetes. In diabetes, CH(corr) and CRF(corr) are correlated to HbA1c, suggesting that the biomechanical properties of the cornea are altered depending on the glucose control.     

超声乳化术对伴有糖尿病的白内障患者角膜内皮的影响

目的：观察伴有糖尿病的白内障患者与单纯白内障患者在超声乳化术后角膜内皮的变化情况。

方法：选取2016-10/2017-06在广西壮族自治区人民医院确诊的白内障(cataract)患者78例92眼,按照有无糖尿病分为糖尿病组与非糖尿病组,其中糖尿病组40例44眼,非糖尿病组38例48眼。所有患者均由同一经验丰富的眼科医师行白内障超声乳化术联合人工晶状体植入术,分别于术前,术后1、4、8wk采用非接触式角膜内皮计数仪检测角膜内皮细胞密度(corneal endothelial density,CED)、六角形细胞比例(hexagonal cell percentage,HCR)、变异系数(variation coefficients,CV)、中央角膜厚度(central corneal thickness,CCT)。利用共焦显微镜记录术前、术后4、8wk的角膜内皮细胞形态。分别观察两组术中虹膜松弛综合征的发生情况。

结果：糖尿病组与非糖尿病组术前比较,角膜内皮六角形细胞比例降低,变异系数增大,差异均有统计学意义(P<0.05),角膜内皮细胞密度及中央角膜厚度差异均无统计学意义(P>0.05); 糖尿病组与非糖尿病组术后不同时间点相比较,六边形细胞比例减低,变异系数增大,差异均有统计学意义(P<0.05),角膜内皮细胞密度及中央角膜厚度差异均无统计学意义(P>0.05); 两组术后1、4、8wk的角膜内皮细胞密度及六角形细胞比例相较于术前均明显降低,变异系数相较于术前明显增高,差异均有统计学意义(P<0.05),术后1wk的中央角膜厚度相较于术前明显增厚,差异有统计学意义(P<0.05),而术后4、8wk与术前相比无统计学意义(P>0.05); 糖尿病组与非糖尿病组术前、术后4、8wk的角膜内皮细胞形态比较,术前糖尿病组角膜内皮细胞形态异型性较大,胞体大小不一,术后4wk糖尿病组的内皮细胞多形性增多,胞体大小各异,可见较大细胞核,术后8wk糖尿病组恢复较慢,仍可见不规则的内皮细胞及尚大的细胞核。糖尿病组术中虹膜松弛综合征的发生率为14%,非糖尿病组发生率为0。

结论：糖尿病及超声乳化术都会对角膜内皮细胞造成损害,同时超声乳化术对糖尿病患者的角膜内皮细胞形态影响较大且恢复较慢。糖尿病可能与虹膜松弛综合征的发生有关。     

糖尿病患者行玻璃体视网膜手术对角膜内皮细胞的影响

目的：探讨糖尿病患者与非糖尿病患者行玻璃体视网膜手术前后对角膜内皮细胞密度和形态学的影响。

方法：收集60例患有糖尿病患者(糖尿病组)和60例非糖尿病患者(对照组),其中30例糖尿病组和30例对照组患者行玻璃体切割联合硅油填充手术,30例糖尿病组和30例对照组患者行晶状体玻璃体切割联合硅油填充手术。检测两组患者术前1d及术后3mo角膜内皮细胞密度(cell densities,CD)、内皮细胞面积变异系数(coefficient of variation,CV)、六角形细胞百分比值(ratio of hexagonal cells,RHC)。比较两组患者手术前后角膜内皮细胞变化的差异。

结果：玻璃体切割联合硅油填充术在糖尿病组与对照组角膜内皮细胞变异系数和六角形细胞百分比手术前后相比差异均有统计学意义, 晶状体玻璃体切割联合硅油填充术在糖尿病组和对照组角膜内皮细胞密度、变异系数及六角形细胞百分比手术前后相比差异均有统计学意义; 晶状体玻璃体切割联合硅油填充术在糖尿病组手术前后角膜内皮细胞密度、变异系数、六角形细胞百分比的差值与对照组相比差异有统计学意义。

结论：玻璃体切割联合硅油填充手术对角膜的影响主要表现在角膜内皮细胞的形态改变; 而与非糖尿病患者相比,糖尿病患者行晶状体玻璃体切割联合硅油填充术角膜内皮细胞形态、密度的改变较非糖尿病患者明显,因此术前角膜内皮细胞的严格检查对于糖尿病患者术后视觉的恢复具有重要意义。     

The corneal endothelium of diabetic patients. A study using specular microscopy

As the endothelial cells of the human cornea cannot perform mitosis, any metabolic alteration that destroys the cells should result into a decrease in cell density. This study was designed to demonstrate this phenomenon in diabetics as we know that diabetes alters endothelial cells, capillaries at least. On the assumption that capillary endothelium has the same mesodermal origin and almost the same metabolic function as the corneal endothelium, we tried to verify whether the corneal endothelium from diabetic subjects differs from non diabetic controls. As corneal endothelium can be studied in vivo by specular microscopy, it was interesting to verify whether this method could provide evidence of the conditions of the endothelial cells in the diabetic subject. Our study in specular microscopy involved 101 cases. We found slightly inferior values of the corneal endothelial cells density in diabetic subjects compared to the control subjects but no correlation between the values of endothelial cell density and the various parameters in diabetic patients: age, duration of diabetes, corneal thickness. This is correlated to other studies in which the morphology of endothelial cells differed between diabetic and non-diabetic subjects. We concluded that diabetes alters but does not significantly destroy the corneal endothelial cell. This result must be taken into account in corneal surgery as the diabetic cornea is a high risk cornea.     

Association between corneal hysteresis and central corneal thickness in glaucomatous and non‐glaucomatous eyes

Purpose: We aimed to determine corneal hysteresis values (CH) using the ocular response analyser (ORA) in non‐glaucomatous and glaucomatous eyes and their relationship with central corneal thickness (CCT). Methods: Corneal hysteresis, intraocular pressure (IOP) as measured by Goldmann applanation tonometry (GAT) and CCT were prospectively evaluated in 74 non‐glaucoma subjects with IOP < 21 mmHg and in 108 patients with treated primary open‐angle glaucoma (POAG). One eye in each subject was randomly selected for inclusion in the analysis. Results: Mean (± standard deviation [SD]) age was 59.2 ± 14.2 years in the non‐glaucoma group and 62.4 ± 9.8 years in the glaucoma group. Mean (± SD) GAT IOP was 15.7 ± 2.65 mmHg and 16.38 ± 2.73 mmHg in the non‐glaucoma and glaucoma groups, respectively. There was no statistically significant difference between the two groups in mean age (p = 0.396) or mean GAT IOP (p = 0.098). Mean (± SD) CH was 10.97 ± 1.59 mmHg in the non‐glaucoma and 8.95 ± 1.27 mmHg in the glaucoma groups, respectively. The difference in mean CH between the two groups was statistically significant (p < 0.0001). There was a strong positive correlation between CH and CCT in the non‐glaucoma group (r = 0.743) and a significantly (p = 0.001) weaker correlation (r = 0.426) in the glaucoma group. Conclusions: Corneal hysteresis was significantly lower in eyes with treated POAG than in non‐glaucomatous eyes. The corneal biomechanical response was strongly associated with CCT in non‐glaucoma subjects, but only moderately so in glaucoma patients. It can be assumed that diverse structural factors, in addition to thickness, determine the differences in the corneal biomechanical profile between non‐glaucomatous and glaucomatous eyes. Corneal hysteresis could be a useful tool in the diagnosis of glaucoma.     

Central corneal thickness and intraocular pressure measures in human corneas with endothelial guttata: an observational quality control study

Purpose: The aim of the present study was to assess central corneal thickness (CCT) and intraocular pressure (IOP) in eyes where the corneas were affected by different degrees of severity of endothelial pseudo‐guttata or guttata. Methods: In a prospective, case series observational study, non‐contact tonometry and non‐contact specular microscopy (NCSM) with pachymetry for central corneal thickness measures were undertaken as routine procedures on predominantly older patients without a history of corneal problems or contact lens wear. For those showing any signs of corneal endothelial abnormalities, images of the central cornea endothelium were further processed to measure the area (as a percentage) occupied by the guttata. Results: Abnormal endothelial images were obtained from 43 patients (seven with bilateral changes) with an average age of 67.5 years. Between 1.5 and 54.9 per cent of the endothelial images were affected by guttata, which were assigned grade 1 (20 eyes), grade 2 (18 eyes) or grade 3 (11 eyes). When assessed by grade, the central corneal thickness increased and the measured IOP decreased as the guttata became more numerous and confluent. Regression analyses revealed only a weak association between central corneal thickness (p = 0.044, r = 0.149) or the measured IOP (p = 0.090, r = ‐0.244) and the extent of the guttata (percentage). With the apparently contrasting IOP and central corneal thickness effects, no significant IOP‐CCT relationship was noted (p ≥ 0.268, r ≤ 0.160). Conclusions: Where corneas have mild‐to‐modest non‐dystrophic endothelial guttata, there may be a less predictable effect of corneal thickness on the outcome of tonometry.     

Ⅱ型糖尿病性视网膜病变患者角膜内皮细胞结构变化的研究

目的：探讨非胰岛素依赖型糖尿病合并视网膜病变后其内皮细胞密度及形态学的变化。方法：选择40例糖尿病视网膜病变患者，分为增殖型视网膜病变组和非增殖型视网膜病变组。观察其内皮细胞密度及形态学变化，并与正常对照组进行比较，统计学分析。结果：糖尿病增殖型视网膜病变患者角膜内皮细胞密度及六边形细胞百分比明显降低，变异系数增加，糖尿病非增殖型视网膜病变患者角膜内皮细胞密度降低，形态学与下对照组比较差异无显著性。结论：非胰岛素依赖型糖尿病视网膜病变患者其角膜内皮细胞结构有异常变化。     

Cambios morfométricos de las células del endotelio corneal en el síndrome pseudoexfoliativo y glaucoma pseudoexfoliativo

ObjetiveTo evaluate the corneal endothelial morphometry and central corneal thickness (CCT) in pseudoexfoliative (PEX) eyes with and without glaucoma and to compare with normal eyes and eyes with primary open-angle glaucoma (POAG).MethodA total of 166 patients were included in this study: 36 eyes with pseudoexfoliation syndrome (PXS), 30 eyes with pseudoexfoliation glaucoma (PXG), 40 eyes with POAG, and 60 normal eyes. Corneal endothelial cell density (ECD), coefficient of variation (CV) in cell size, and percentage of hexagonal cells, were measured using a non-contact specular microscope, whereas CCT was measured with an ultrasonic pachymeter.ResultsECD and percentage of hexagonal cells were lower in PEX groups and in the POAG group compared with normal eyes, while the CV in cell size was greater. There was a tendency for greater cell loss and morphological abnormalities of the corneal endothelial cells in PXG eyes compared to PXS eyes, when all pseudoexfoliative eyes were analyzed together. Changes in endothelial cells increased with age. There were no significant differences in mean CCT between the four groups.ConclusionEndothelial cell density is significantly decreased, and pleomorphism and polymegathism of cells are increased in PEX eyes, particularly when intraocular pressure is high.     

Comparison of Central Corneal Thickness using Ultrasound Pachymetry during Corneal Collagen Cross-linking

 PURPOSE:To study variation in central corneal thickness (CCT) during corneal collagen cross-linking(CXL) using ultrasound pachymetry． METHODS:Twenty patients (26 eyes) with progressing keratoconus undergoing riboflavin-UVA-induced CXL were involved in this study. Intraoperative CCT measurement using ultrasonic pachymetry was performed during the procedure．Measurements were obtained before operation, after epithelial removal, after riboflavin drop instillation, and after UVA irradiation. RESULTS:Mean CCT was 495±56 and 450±52 μm before and after epithelial removal, respectively. Mean CCT was 443±42 and 411±39 μm after riboflavin drop instillation and after UVA irradiation, respectively. Statistically significant decreases in CCT occurred between the preoperative period and after epithelial removal, after riboflavin drop instillation and after UVA irradiation. Twenty-six eyes from 20 patients undergoing CXL were divided into 2 groups (I with CCT &;gt;or = 400 μm after UVA irradiation and II with CCT &;lt;400 μm after UVA irradiation). No statistically significant difference was noted between I and II in preoperative endothelial cell count, but a statistically greater postoperative endothelial cell count was noted in I compared to II. A statistically significant difference was evident between preoperative and postoperative endothelial cell counts in Group II (P &;lt;0.05). CONCLUSION:Performing CXL with the use of riboflavin and UVA irradiation resulted in a statistically significant decrease in CCT, to a level where the corneal endothelium may be damaged.     

Ⅱ型糖尿病患者白内障术后5年角膜内皮细胞的形态学变化

目的观察Ⅱ型糖尿病患者白内障超声乳化手术后5年角膜内皮细胞的形态学变化。设计回顾性病例系列。研究对象选取2008年1月至2008年12月在北京友谊医院行晶状体超声乳化手术的白内障患者71例（87眼）。方法合并Ⅱ型糖尿病的白内障患者38例（44眼）为糖尿病组,单纯老年性白内障患者33例（43眼）作为对照组。所有患者均行白内障超声乳化联合人工晶状体植入术,分别于术前及术后5年采用角膜内皮镜观察角膜内皮数量及形态学的变化。主要指标角膜内皮细胞密度、平均内皮细胞面积、变异系数。结果术前,糖尿病患者与对照组相比内皮细胞密度、平均内皮细胞面积、变异系数均无明显差异（P〉0．05）。糖尿病患者术后5年与术前相比,角膜内皮细胞密度降低,平均内皮细胞面积增加,变异系数增加（P均〈0．01）。对照组患者术后5年与术前相比,变异系数增加（P〈0．01）,角膜内皮细胞密度和平均内皮细胞面积无明显差异（P均〉0．05）。术后5年,糖尿病患者的内皮细胞密度明显低于对照组（P〈0．01）,平均内皮细胞面积明显高于对照组（P〈0．05）,变异系数与对照组无统计学差异（P〉0．05）。结论本小样本的回顾性病例研究显示,与正常人相比,糖尿病患者白内障术后角膜内皮细胞损伤重,修复慢,需要长期随访。     

The relationship between soluble L-selectin and the development of diabetic retinopathy

Diabetic retinopathy is a leading cause of adult vision loss and blindness. Earlier studies have shown that polymorphonuclear neutrophils play an important role in the pathogenesis of diabetic vascular complications. Stimulation of these cells is associated with the desquamation of L-selectin. The aim of the study was to evaluate the relationship between the serum concentration of L-selectin and the development of retinopathy in Type 2 diabetic patients. The study comprised 51 Type 2 diabetic patients, aged 65.2 +/- 7.5 years, with a diabetes duration of 10.1 +/- 8.9 years and HbA1c of 8.2 +/- 1.4. The study subjects were divided into two groups: Group A diabetic patients with retinopathy (n = 28) and Group B diabetic patients without retinopathy (n = 23). Twenty age- and sex-matched nondiabetic healthy subjects were enrolled as the control group. Patients with any inflammatory disease were excluded. Retinopathy was assessed by centrally graded retinal photographs. The serum concentration of sL-selectin was estimated using an ELISA test. We observed significantly higher serum concentrations of sL-selectin in Type 2 diabetic patients with retinopathy than in healthy subjects (36.5 +/- 18.1 vs. 11.4 +/- 7.5 ng/ml, p < 0.001). There was also a significant difference between Group A and Group B (36.5 +/- 18.1 vs. 24.2 +/- 13.5 ng/ml, p < 0.05) as well as between Group B and the controls (24.2 +/- 13.5 vs. 11.4 +/- 7.5 ng/ml, p < 0.01) with regard to sL-selectin levels. sL-selectin was significantly correlated with HbA1c (r = 0.93, p < 0.001) and with diabetes duration (r = 0.44, p < 0.001). These results suggest that there was a strong relationship between sL-selectin and diabetic retinopathy. The strong correlation between sL-selectin and HbA1c levels supports the concept that the sL-selectin level is increased with poor glycemic control, which may affect endothelial cell activity and cause subsequent microvascular complications.     

非穿透性小梁切除术与小梁切除术后角膜内皮细胞变化的对比分析

目的探讨角膜内皮细胞在非穿透性小梁切除术与小梁切除术后的变化及临床意义。方法采用非接触眼压计、角膜内皮计及细胞图像分析系统观察14例(16只眼)非穿透小梁切除术与24例(25只眼)小梁切除术患者手术前后眼压、中央角膜厚度、角膜内皮细胞情况,并对结果进行统计学分析。结果非穿透性小梁切除组术后眼压显著下降(P<0.05),中央角膜厚度(CCT)、最小细胞面积(MIN)、最大细胞面积(MAX)、平均细胞面积(AVE)、细胞面积变异系数(CV%)和细胞密度(CD)均较术前无显著性差异(P>0.05);小梁切除组术后眼压显著下降(P<0.05),中央角膜厚度(CCT)较术前增加(P<0.05),平均细胞面积(AVE)较术前增加(P<0.05),细胞密度(CD)及六角形细胞百分数(H%)均较术前显著减少(P<0.05)。结论非穿透性小梁切除术和小梁切除术均可有效控制眼压,非穿透性小梁切除术后角膜内皮细胞变化较小,手术安全性高。     

飞秒激光辅助的超声乳化手术对小梁切除术后并发性白内障患者角膜的影响

目的　比较飞秒激光辅助的超声乳化手术和常规超声乳化手术对小梁切除术后并发性白内障患者角膜的影响。方法　前瞻性研究。选取我院2017年1月至12月收治的小梁切除术后并发性白内障患者100例100眼,利用随机数字表法将患眼分为两组,分别为行飞秒激光辅助的超声乳化手术的试验组和行常规超声乳化手术的对照组,每组各50例50眼。记录两组患者术前最佳矫正视力(best corrected visual acuity,BCVA)及术后裸眼视力(uncorrected visual acuity,UCVA)。用非接触角膜内皮显微镜（SP-2000P）分别于术前及术后 1个月、3个月测量角膜内皮细胞密度（endothelial cell density,ECD）;用 Pentacam分析仪分别于术前及术后1 d、1个月、3个月测量中央角膜厚度（central corneal thickness,CCT）和角膜体积（corneal volume,CV）。对比两组术中各项超声参数及术后各指标间的差异。结果　两组患者核硬度分级、手术时间、灌注液量相比,差异均无统计学意义（均为P＞0.05）。两组间超声时间、超声能量、超声累积释放能量之间,差异均有统计学意义（均为P＜0.05）。两组术后1 d UCVA相比差异有统计学意义(P=0.025),术前BCVA和术后1个月UCVA两组相比差异均无统计学意义(均为P＞0.05)。术前两组患者的 ECD、CCT、CV相比,差异均无统计学意义（均为P＞0.05）。术后1个月、3个月两组间ECD相比差异均有统计学意义（均为P＜0.05）,但ECD减少率相比差异均无统计学意义（均为P＞0.05）。术后1 d、1个月两组间CCT、CV相比差异均有统计学意义（均为P＜0.05）,而术后3个月两组间的 CCT、CV相比差异均无统计学意义（均为P＞0.05）。术后 1 d、1 个月,两组间 CCT、CV增加率相比差异均有统计学意义（均为P＜0.05）。术后 3 个月,两组患者的 CCT、CV 增加率相比差异均无统计学意义（均为P＞0.05）。结论　飞秒激光辅助的超声乳化手术能够减轻手术对角膜内皮细胞的损害,缩短角膜水肿恢复时间,降低术后角膜内皮失代偿的风险,提高小梁切除术后并发性白内障手术的安全性。     

Biomechanical profile of the cornea in primary congenital glaucoma

Purpose: The aim of our study was to investigate the biomechanical properties of the cornea in primary congenital glaucoma (PCG) and to identify the potential ocular determinants, which affect the corneal biomechanical metrics. Methods: Corneal hysteresis (CH), corneal resistance factor (CRF) and central corneal thickness (CCT) were measured in 26 patients with PCG (40 eyes) with the aid of ocular response analyser. In vivo laser‐scanning confocal microscopy was used for the estimation of stromal keratocyte density (KD) and the evaluation of corneal endothelium. Twenty normal subjects (40 eyes) served as controls. Student’s t‐test and Pearson’s correlation coefficients were used for statistical analysis. p Values <0.05 were considered statistically significant. Results: Corneal hysteresis, CRF and CCT were significantly reduced in patients with PCG (all p < 0.05). Corneal hysteresis and CRF negatively correlated with the corneal diameter in both groups (r₁ = ?0.53, r₂ = ?0.66, p < 0.001 for CH and r₁ = ?0.61, r₂ = ?0.69, p < 0.001 for CRF). Moreover, we identified a significant correlation between CH and CRF with CCT in both groups (r₁ = 0.51, r₂ = 0.48, p < 0.001 for CH and r₁ = 0.45, r₂ = 0.44, p < 0.001 for CRF). Mean KD was significantly reduced both in the anterior and posterior corneal stroma in patients with PCG (764 ± 162 and 362 ± 112 cells/mm², respectively) compared with controls (979 ± 208 and 581 ± 131 cells/mm², respectively) (p < 0.001). There was no significant correlation between the keratocyte density in anterior and/or posterior stroma and CH or CRF in any group (r₁ = 0.29, r₂ = 0.31, p < 0.06). Mean endothelial cell density was also significantly reduced in PCG group (2920 ± 443 cells/mm²) compared with control group (3421 ± 360 cells/mm²) (p < 0.001). Pleomorphism and polymegalism were significantly increased in corneal endothelium of patients with PCG. Conclusions: Our results showed a significant reduction in CH and CRF in PCG. Both CH and CRF were negatively correlated with corneal diameter. A significant correlation of CH and CRF with CCT was identified in both groups. Keratocyte density was decreased in PCG, but did not have a significant impact on CH and CRF. Mean endothelial density was also decreased in PCG. Our results suggest that reduced CCT and increased corneal diameter are major ocular determinants for the modified corneal biomechanical profile in PCG, while cellular alterations in corneal stroma and endothelium have no significant biomechanical impact.     

Comparison of corneal endothelial changes following phacoemulsification in diabetic and non-diabetic patients

Purpose:To study corneal endothelial changes post phacoemulsification in diabetic and non-diabetic patients.Methods:A comparative, prospective, observational study was conducted on 100 diabetic and 100 non-diabetics who underwent phacoemulsification. All patients were operated by the same surgeon by using the phaco chop technique to exclude any surgeon-related bias. Endothelial cell count, CCT, and coefficient of variance (CV) were measured with a specular microscope along with BCVA preoperatively and at 1 week, 4 weeks, and 3 months postoperatively. For statistical analysis, data were analyzed by using SPSS (version 27.0; SPSS Inc., Chicago, IL, USA). Data were summarized as mean and standard deviation for numerical variables and count and percentages for categorical variables. Chi square test, independent sample T test, and paired T test were used to compare the data. P ≤ 0.05 was considered statistically significant.Results:Postoperatively at 1 week, 4-week, and 3 months follow-up intervals, the mean endothelial cell count and coefficient of variance were significantly higher, and the mean percentage of hexagonal cells was significantly lower in non diabetic as compared to the diabetic group. A significant difference in mean central corneal thickness of the two groups was observed at 1-week and 4-weeks postoperative intervals; at both these intervals, the mean value was significantly higher in non diabetic as compared to the non-diabetic group. However, at 3-months post-operative interval, the difference between the two groups was not significant statistically. Mean BCVA values were significantly higher in diabetic as compared to the diabetic group at all three follow-up intervals.Conclusion:The findings of the present study show that endothelial cell characteristics are adversely affected in diabetic eyes as compared to non-diabetic patients undergoing phacoemulsification; this might also have an effect on the visual outcomes.