目的 对比A型超声角膜测厚仪、OrbscanⅡ眼前节分析仪和Pentacam眼前节分析仪测量准分子激光原位角膜磨镶术（LASIK）前后中央角膜厚度的差异。 方法 2010年10月－2011年3月，分别使用A型超声角膜测厚仪、OrbscanⅡ和Pentacam眼前节分析仪测量137例（274只眼）近视患者LASIK前后中央角膜厚度，并对测量结果进行配对t检验和Pearson相关性分析。 结果 LASIK术前A型超声、OrbscanⅡ和Pentacam测量值分别为（526.6 ± 34.1）、（516.6 ± 34.2）、（539.8 ± 31.5） μm，Pentacam测量值较A型超声和OrbscanⅡ测量值高，差异有统计学意义（P＜0.05），而A型超声和OrbscanⅡ测量值之间差异无统计学意义（P＞0.05）；LASIK术后6个月A型超声、OrbscanⅡ和Pentacam测量值分别为（448.2 ± 48.5）、（391.9 ± 58.5）、（451.5 ± 46.4） μm，LASIK术后A型超声和Pentacam测量值无差异（P＞0.05），而OrbscanⅡ测量值较A型超声和Pentacam低；Pearson相关分析显示，LASIK术后Pentacam和A型超声CCT测量值呈高度相关（P＜0.05）。 结论 3种仪器的中央角膜厚度测量值不可互换，LASIK术后A型超声和Pentacam量值较为准确。Objective To compare the difference in measurements of central corneal thickness (CCT) using A-scan, OrbscanⅡand Pentacam before and after laser in situ keratomileusis (LASIK). Methods Between October 2010 and March 2011, the CCT of 137 patients (274 eyes) were measured by A-scan, OrbscanⅡ and Pentacam, and the results were analyzed by paired t-tests and Pearson correlation. Results Before LASIK, the values of CCT measured by A-scan, OrbscanⅡ and Pentacam were (526.6 ± 34.1), (516.6 ± 34.2), and (539.8 ± 31.5) μm respectively; paired t-tests showed the CCT values obtained with Pentacam were significantly higher than those with other methods (P＜0.05), but there were no statistical significant differences between OrbscanⅡand Pentacam measurements (P＞0.05). Six months after LASIK, the values of CCT measured by A-scan, OrbscanⅡand Pentacam was (448.2 ± 48.5), (391.9 ± 58.5), and (451.5 ± 46.4) μm respectively; the CCT values obtained with A-scan and Pentacam didn’t differ much from each other (P＞0.05), and the CCT values obtained with OrbscanⅡwere lower than those obtained with A-scan and Pentacam. There was a high correlation between A-scan and Pentacam measurements. Conclusion The these methods measuring CCT could not be used interchangeably, and A-scan and Pentacam after LASIK were more precise than OrbscanⅡ.
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.
Objective To observe the biocompatibility of the acellular corneal stroma materials prepared by three different methods. Methods Three different serial digestion methods were used to produce the acellular corneal stroma materials. The biocompatibility of the materials was investigated by the cell seeding and the materials were implanted into the rabbit corneal stroma layer. Results The cells in the materials 1 and 2 were not decellularized completely. The rabbit corneal fibroblasts died on the materials 1 and 2 after the cell seeding for 3-4 days. An obvious rejection could be observed after the implantation. The cells in material 3 were decellularized completely and the collagen fibers or elastic fibers were reserved integrally，showing a typical three-dimensional net work. The rabbit corneal fibroblasts could expand on the materials in vitro. No obvious rejection could be observed and the materials were gradually absorbed. Conclusion The acellular porcine cornea stroma materials prepared by trypsin-Dnase-Rnase are suitable for reconstruction of the tissue engineered cornea.
Objective To compare the effects of the denudedfreeze-dried-amniotic-membrane and the denuded freeze-dried bovine corneal stroma when they were explanted to repair the corneal defect of rabbits. Methods The amnia from healthy human placentae were prepared with the method reported by LUO Jingcong, which were freeze-dried and sterilized. The bovine cornea was also denuded by typsin, rinsed, freeze-dried, and sterilized. Twenty Japan rabbits weredivided into group A(the amniontic group) and group B(the bovine-corneal-stroma group) at random. The defect was made, which was 7.5 mm in diameter and 1/3 ofthe thickness of the cornea, and the two kinds of materials were explanted to repair the defect. The vascularization and the changes of the operated eye were observed. The samples were taken at 2, 4 and 8 weeks for histologicalexamination. Results The explanted materials were not melted or excluded. There were visible neovessels in both groups, yet there was no significant difference between them. According to the histological observation, there was severe inflammation in both groups 2 weeks after operation, the fibroblasts were proliferated, and the collagen fibers were disorganized; however,the reactions became milder from 4 weeks after operations,andthe neovessles could be seen in groups A and B; at 8 weeks, the collagen fibers were more organized in groups A and B; however,there was still a small area of disorganized fibers left. Conclusion The two materials can lead to rejection to some extent, and so they need to be improved.
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.
In order to rescue the serious cornea-sclera defect, normal piece of a sclera from the damaged eye was used to serve as a donor material to repair the cornea-sclera defect. Eighteen cases were treated by transplantation of sclera graft with the operation to decompress the intra-ocular tension and to perform an artificial pupil from 1979 to 1994. Because the ocular-store seriously lacks in mostly internal locality, in the 18 cases, laceration of avulsive in 5 cases, severe corneal fistula complicated to other corneal diseases in 8 cases, locolized staphyloma of aornea in 2, laceration of sclera fistula in 1. The resulte were: The repairs were all healed up in an average of 20 days. The tension returned to normal and the vision was improved. The scleral graft was fused with the cornea, and the white area form the graft tended to reduce in size gradually with increase in transparency. There was no sign of iritis and rejection reaction. Follow-up of 3 to 36 months showed that the grafting operation was simple and an easy method, at the same time, once gained effect if would prevent or cure blindness.
Objective To observe the efficacy of photodynamic therapy for vitelliform macular dystrophy(VMD) with choroidal neovascularization(CNV). Methods The clinical data of 7 patients (7 eyes) of VMD with CNV who had undergone photodynamic therapy (PDT) were retrospectively analyzed. The patients were 4 males and 3 females, aged from 20 to 54 years. The patients received the examinations of best corrected visual acuity (BCVA), slitlamp microscopy, fundus photography, fluorescein angiography (FFA), indocyanine green angiography (ICGA), spectral domain OCT(SD-OCT), electrooculogram（EOG）and electroretinogram (ERG)before and after PDT. The BCVA ranged from finger counting to 0.6. Retinal edema and the subretinal fluid were observed. The mean thickness of central retina was (506.00plusmn;30.71) mu;m. PDT was performed according to the standard treatment. The follow-up period ranged from 2 to 11 months with the mean of 6.3 months. The changes of BCVA, CNV and side effects were observed after treatment. Results BCVA improved in all patients ranging from 0.12 to 1.0. The regression of the CNV and resolution of the subretinal fluid were observed by FFA, ICGA and SD-OCT after PDT. The mean thickness of central retina was reduced to (401.00plusmn;52.22) mu;m. There was no PDTassociated ocular or systemic side effect. Conclusions PDT is an effective and safe treatment for VMD with CNV. It may improve or stabilize the visual acuity.
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)