目的 探讨聚乙二醇滴眼液对准分子激光上皮下角膜磨镶术（LASEK）后角膜雾状混浊（haze）影响的临床研究。 方法 回顾性分析2009年3月－2010年3月行LASEK的患者45例90只眼的临床资料。患者屈光度（?4.68 ± 2.30）D（?1.75～?6.50 D），随机分为聚乙二醇滴眼液组（试验组）和对照组，术后定期随访观察两组角膜haze形成、角膜上皮愈合时间、视力恢复情况及屈光度。 结果 术后1、3、6个月，两组haze形成差异无统计学意义（P＞0.05），试验组术后第1、3、5天角膜刺激症状明显轻于对照组（P＜0.05），上皮愈合速度较对照组更快（P＜0.05）。 结论 LASEK术后应用聚乙二醇滴眼液虽然能减轻术后患者角膜刺激症状,能促进角膜上皮更快愈合，但是不能减轻haze的形成。
目的:探讨高龄白内障患者术前角膜内皮功能状态。方法:对从2007年11月到2008年10月的66例年龄在80岁或以上的左眼白内障患者术前角膜内皮细胞形态及中央角膜厚度进行回顾性分析。分析参数包括角膜内皮细胞密度,内皮细胞平均面积,最大细胞面积和最小细胞面积,内皮细胞变异系数,面积标准差,六角形细胞比例及角膜中央厚度。结果:患者的角膜内皮细胞平均密度为(2720.3±324.6)个/mm2,平均细胞面积为(375.4±70.3)μm2,最大细胞面积(922.1±243.5)μm2,最小细胞面积(131.2±40.2)μm2,面积标准差(143.5±34.8)μm2,细胞变异系数(38.0±7.3)%,六角形细胞比例(52.8±10.1)%。中央角膜厚度与角膜内皮细胞密度之间无相关性。结论:高龄人白内障患者的角膜内皮细胞密度高,角膜功能基本正常，是保持角膜透明的基础,为眼内手术或治疗提供安全保障。
In order to understand how the biomechanical properties of rabbit cornea change over time after corneal ablation, 21 healthy adult rabbits were used in this study, with the left eye as experimental side and the right eye as the control side. Firstly, a lamellar knife was used to remove a portion of the anterior corneal surface tissue (30%~50% of the original corneal thickness) from the left eye of each rabbit, as an animal model simulating corneal refractive surgery. Secondly, postoperative experimental rabbits were kept for one, three, or six months until being euthanized. Strip specimens were produced using their corneas in vitro to perform a uniaxial tensile test with an average loading-unloading rate of approximately 0.16 mm/s. Finally, the visco-hyperelastic material constitutive model was used to fit the data. The results showed that there was a significant difference in the viscoelastic parameters of the corneas between the experimental and the control eyes at the first and third postoperative months. There was a difference in tangential modulus between the experimental and the control eyes at strain levels of 0.02 and 0.05 at the third postoperative month. There was no significant difference in biomechanical parameters between the experimental and the control eyes at the sixth postoperative month. These results indicate that compared with the control eyes, the biomechanical properties of the experimental eyes vary over postoperative time. At the third postoperative month, the ratio of corneal tangential modulus between the experimental and the control eyes significantly increased, and then decreased. This work lays a preliminary foundation for understanding the biomechanical properties of the cornea after corneal refractive surgery based on rapid testing data obtained clinically.
Objiective To observe the changes of angioarchitecture of the optic disc in cats eyes after radial optic neurotomy (RON). Methods Ten healthy adult cats underwent unilateral RON randomly in 10 eyes as an operative group in this trial, and the fellow eyes (10 eyes) were as the control group. The colophony samples of vascular angioarchitecture of 20 eyes were made 90 days after RON and scanning electron microscope was used for the observation. Results In the control group, the blood supply of optic disc mainly came from the short posterior ciliary artery, pial artery, and retinal ciliary artery; the choroidal capillary vessels around the optic disc didnprime;t take part in the blood supply in the anterior area; retinal central vascular system and complete arterial circle around the optic nerves were not seen. In the operative group, a V-shaped defect of the optic disc, retinal blood vessels and choroidal capillary vessels was found at the surgical incision; no injury of retinal blood vessels and choroidal large vascular layer was seen, and neovascularization at the incision were not found. Conclusions RON may cause the vascular defect of the optic disc and the peripheral local tissues. The depth of the incision doesnprime;t reach the Zinn-Hallers circle. (Chin J Ocul Fundus Dis, 2007, 23: 170-172)
Objective To review research progress of corneal tissueengineering.Methods The recent articles on corneal tissue engineering focus on source and selection of corneal cells, the effects of growth factors on culture of corneal cells in vitro. The preparation and selection of three-dimensional biomaterial scaffolds and their b and weak points were discussed. Results The corneal tissue engineering cells come from normal human corneal cells. The embryo corneal cell was excellent. Several kinds of growth factors play important roles in culture, growth and proliferation of corneal cell, and incroporated into matrix.Growth factors including basic fibroblast growth factor, keratinocyte growth factor, transforming growth factor β1 and epidermal growth factor was favor to corneal cell. Collagen, chitosan and glycosaninoglycans were chosen as biomaterial scaffolds. Conclusion Human tissue engineering cornea can be reconstructed and transplanted. It has good tissue compatibility and can be used as human corneal equivalents.
Objective To analyze the risk factors for persistent corneal epithelial defects (PCED) after pars plana vitrectomy (PPV) in patients with proliferative diabetic retinopathy (PDR). Methods A total of 201 PDR patients (201 eyes) who received PPV were enrolled in this retrospective study. There were 86 males (86 eyes) and 115 females (115 eyes). The patients aged from 30 to 81 years, with the mean age of (57.94±9.65) years. Among them, 159 patients were ≥50 years of age, and 42 patients were ＜50 years of age. There were 36 patients with HbA1c ＜7.0%, 165 patients with HbA1c ≥7.0%. There were 93 right eyes and 108 left eyes. There were 93 right eyes and 108 left eyes. The diabetic retinopathy stages were as follows: stage Ⅳ in 24 eyes, stage Ⅴ in 78 eyes and stage Ⅵ in 99 eyes. The operation time was ranged from 1 to 4 hours, with an average of 2 hours. Among the 201 eyes, corneal epidermis were scraped on 25 eyes; 70 eyes were combined with cataract surgery; a laser photocoagulation count ＜1000 points was performed in 78 eyes, and ＞1000 points were performed in 123 eyes. Sixty-one eyes involved intravitreal silicone oil tamponade, 18 eyes involved intravitreal tamponade with C3F8, and 122 eyes were not involved with intraocular tamponade. Postoperative persistent intraocular hypertension was defined as an intraocular pressure (IOP) ≥21 mmHg (1 mmHg=0.133 kPa) after PPV with necessary treatment using IOP-lowering medications for ≥2 weeks. The diagnostic criteria for corneal epithelial defects were taken from the Expert Consensus on Clinical Diagnosis and Treatment of Corneal Epithelial Defect in China (2016). The corneal epithelial defect was diagnosed as PCED if it was treated with common methods such as a lacrimal substitute or corneal contact lens, but showed no improvement and no signs of healing for ≥2 weeks. The incidence of PCED after eye surgery was recorded and its related risk factors were analyzed. A multivariate logistic regression was used to analyze the risk factors for PCED, which were expressed as a odds ratio (OR) and a 95% confidence interval (CI). Results Of 201 eyes, 16 eyes (7.96%) presented with PCED after surgery and 185 eyes (92.04%) with no PCED. There was no significant difference in the age, sex, and eyes between the patients with or without PCED (χ2=6.548, 0.927, 0.044; P=0.011, 0.336, 0.833). A multivariate logistic regression showed that intraoperative epithelial debridement (OR=13.239, 95%CI 2.999−58.442, P=0.001), intraoperative treatment in combination with cataract surgery (OR=7.448, 95%CI 1.975−28.091, P=0.003), intravitreal tamponade with C3F8 (OR=11.344, 95%CI 2.169−59.324, P=0.004), and postoperative persistent intraocular hypertension (OR=10.462, 95%CI 2.464−44.414, P=0.001) were risk factors for PCED after PPV. Conclusion Intraoperative epithelial debridement, intraoperative treatment in combination with cataract surgery, intravitreal tamponade with C3F8, and postoperative persistent intraocular hypertension are risk factors for PCED in patients with PDR after PPV.
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.
Objective To investigate the feasibility of photochemical tissue bonding (PTB) technique in repairing limbal stem cell (LSC) deficiency and the effect on cornea wound healing. Methods LSCs were isolated from limbus of New Zealand rabbits by tissue block culture method, and then the LSCs of 2nd passage were cultured on de-epithelialized human amniotic membrane (HAM) for 3 weeks to prepare the HAM/LSC grafts. The LSC deficiency models of the left eyes were established by 0.5 mol/L NaOH in 24 New Zealand female rabbits, aged 3-4 months and weighing 1.5-2.0 kg. HAM/LSC grafts were used to repair the cornea wounds by sutures (suture group, n=12) or by PTB technique (PTB group, n=12). The gross was observed including the corneal transparency, erythema, and new blood vessel formation after surgery. At 3 and 28 days, the inflammatory cytokine of interleukin 1β (IL-1β), IL-6, and tumor necrosis factor α (TNF-α) were assayed by ELISA method; and the amount of new blood vessels were quantified by immunohistochemistry staining at 28 days. Results All animals survived to the end of the experiment. At 3 days, there was no obvious difference in the corneal transparency between 2 groups; at 28 days, the corneal transparency of PTB group was higher than that of suture group, and new blood vessels decreased. HE staining showed that mass inflammatory cells infiltrated between graft and cornea basal layer at 3 days, and no new blood vessel formed. inflammatory cells infiltration significantly decreased at 28 days in PTB group; the amount of new blood vessels was (2.0 ± 0.8)/ HP in PTB group and was (6.3 ± 1.3)/HP in suture group, showing significant difference (t=7.966, P=0.002). At 28 days, the concentrations of inflammatory cytokine of IL-1β, IL-6, and TNF-α in suture group were significantly higher than those in PTB group (P lt; 0.05); however, no significant differences were observed between 2 groups at 3 days (P gt; 0.05). Conclusion PTB technique can be used to fix HAM/LSC grafts, which can decrease inflammatory cell infiltration and new vessel formation, and improve the outcomes when compared with suture technique.