AIM: To study the optical property and biocompatibility of a tissue engineering cornea.METHODS: The cross-linker of N-(3-Dimethylaminoropyl)-N'ethylcarbodiimide hydrochloride(EDC)/ N-Hydroxysuccin- imide (NHS) was...AIM: To study the optical property and biocompatibility of a tissue engineering cornea.METHODS: The cross-linker of N-(3-Dimethylaminoropyl)-N'ethylcarbodiimide hydrochloride(EDC)/ N-Hydroxysuccin- imide (NHS) was mixed with Type I collagen at 10% (weight/volume). The final solution was molded to the shape of a corneal contact lens. The collagen concentrations of 10%, 12.5%, 15%, 17.5% and 20% artificial corneas were tested by UV/vis-spectroscopy for their transparency compared with normal rat cornea. 10-0 sutures were knotted on the edges of substitute to measure the corneal buttons's mechanical properties. Normal rat corneal tissue primary culture on the collagen scaffold was observed in 4 weeks. Histopathologic examinations were performed after 4 weeks of in vitro culturing.RESULTS: The collagen scaffold appearance was similar to that of soft contact lens. With the increase of collagen concentration, the transparency of artificial corneal buttons was diminished, but the toughness of the scaffold was enhanced. The scaffold transparency in the 10% concentration collagen group resembled normal rat cornea. To knot and embed the scaffold under the microscope, 20% concentration collagen group was more effective during implantation than lower concentrations of collagen group. In the first 3 weeks, corneal cell proliferation was highly active. The shapes of cells that grew on the substitute had no significant difference when compared with the cells before they were moved to the scaffold. However, on the fortieth day, most cells detached from the scaffold and died. Histopathologic examination of the primary culture scaffold revealed well grown corneal cells tightly attached to the scaffold in the former culturing. CONCLUSION: Collagen scaffold can be molded to the shape of soft contact corneal lens with NHS/EDC. The biological stability and biocompatibility of collagen from animal species may be used as material in preparing to engineer artificial corneal scaffold.展开更多
AIM:To study the impact of scleral flap position,under which the posterior chamber intraocular lenses(PC-IOL) were sulcus-fixed by trans-scleral suture,on cornea astigmatism.METHODS:Twenty-six aphakic or cataract eyes...AIM:To study the impact of scleral flap position,under which the posterior chamber intraocular lenses(PC-IOL) were sulcus-fixed by trans-scleral suture,on cornea astigmatism.METHODS:Twenty-six aphakic or cataract eyes were comprised in this prospective noncomparative case series study.Eleven eyes had traumatic cataract removed without sufficient capsular support,3 had blunt trauma with subluxated traumatic cataract,8 had undergone vitreoretinal surgery and 4 had congenital cataract removed.The average age was 54 years(range 21-74 years),with 17 men and 7 women.The foldable PC-IOL was fixed in sulcus by trans-scleral suture.The incision for IOL implantation was made 1mm posterior to limbus along the steepest meridian of cornea,while scleral flaps to bury the knots of trans-scleral suture were made along the flattest meridian.All the surgeries were performed by a single doctor(Ma L),and the follow up was at least 13 months(range 13-28 months).The preoperative,3 months and 1 year postoperative corneal curvature along the steepest and flattest cornea meridian and overall cornea astigmatism were compared.RESULTS:The curvature along the steepest meridian changed from 44.25±2.22D preoperatively to 44.08±2.16D at 3 months postoperatively,and 43.65±5.23D at 1 year postoperatively(P >0.05);the curvature along the flattest meridian changed from 41.24±2.21D preoperatively to 43.15±3.94D at 3 months postoperatively,and 42.85±5.17D at 1 year postoperatively(P <0.05);and the surgery induced astigmatism(SIA) on cornea was calculated by vector analysis,which was 2.42±2.13D at 3 months postoperatively,and 2.18±3.42D at 1 year postoperatively,the difference was statistically significant(P <0.05).CONCLUSION:The scleral flap made along the flattest meridian,under which the posterior chamber intraocular lenses(PCIOL) were sulcus-fixed by trans-scleral suture,can steepen the cornea in varying degrees,thus reducing preexisting corneal astigmatism.展开更多
基金Scientific and Technological Research Projects of Educational Committee of Liaoning Province of China(No.2008S243)
文摘AIM: To study the optical property and biocompatibility of a tissue engineering cornea.METHODS: The cross-linker of N-(3-Dimethylaminoropyl)-N'ethylcarbodiimide hydrochloride(EDC)/ N-Hydroxysuccin- imide (NHS) was mixed with Type I collagen at 10% (weight/volume). The final solution was molded to the shape of a corneal contact lens. The collagen concentrations of 10%, 12.5%, 15%, 17.5% and 20% artificial corneas were tested by UV/vis-spectroscopy for their transparency compared with normal rat cornea. 10-0 sutures were knotted on the edges of substitute to measure the corneal buttons's mechanical properties. Normal rat corneal tissue primary culture on the collagen scaffold was observed in 4 weeks. Histopathologic examinations were performed after 4 weeks of in vitro culturing.RESULTS: The collagen scaffold appearance was similar to that of soft contact lens. With the increase of collagen concentration, the transparency of artificial corneal buttons was diminished, but the toughness of the scaffold was enhanced. The scaffold transparency in the 10% concentration collagen group resembled normal rat cornea. To knot and embed the scaffold under the microscope, 20% concentration collagen group was more effective during implantation than lower concentrations of collagen group. In the first 3 weeks, corneal cell proliferation was highly active. The shapes of cells that grew on the substitute had no significant difference when compared with the cells before they were moved to the scaffold. However, on the fortieth day, most cells detached from the scaffold and died. Histopathologic examination of the primary culture scaffold revealed well grown corneal cells tightly attached to the scaffold in the former culturing. CONCLUSION: Collagen scaffold can be molded to the shape of soft contact corneal lens with NHS/EDC. The biological stability and biocompatibility of collagen from animal species may be used as material in preparing to engineer artificial corneal scaffold.
基金Government Foundation of Liaoning Province, Shenyang,China(No.20081059,2008860)
文摘AIM:To study the impact of scleral flap position,under which the posterior chamber intraocular lenses(PC-IOL) were sulcus-fixed by trans-scleral suture,on cornea astigmatism.METHODS:Twenty-six aphakic or cataract eyes were comprised in this prospective noncomparative case series study.Eleven eyes had traumatic cataract removed without sufficient capsular support,3 had blunt trauma with subluxated traumatic cataract,8 had undergone vitreoretinal surgery and 4 had congenital cataract removed.The average age was 54 years(range 21-74 years),with 17 men and 7 women.The foldable PC-IOL was fixed in sulcus by trans-scleral suture.The incision for IOL implantation was made 1mm posterior to limbus along the steepest meridian of cornea,while scleral flaps to bury the knots of trans-scleral suture were made along the flattest meridian.All the surgeries were performed by a single doctor(Ma L),and the follow up was at least 13 months(range 13-28 months).The preoperative,3 months and 1 year postoperative corneal curvature along the steepest and flattest cornea meridian and overall cornea astigmatism were compared.RESULTS:The curvature along the steepest meridian changed from 44.25±2.22D preoperatively to 44.08±2.16D at 3 months postoperatively,and 43.65±5.23D at 1 year postoperatively(P >0.05);the curvature along the flattest meridian changed from 41.24±2.21D preoperatively to 43.15±3.94D at 3 months postoperatively,and 42.85±5.17D at 1 year postoperatively(P <0.05);and the surgery induced astigmatism(SIA) on cornea was calculated by vector analysis,which was 2.42±2.13D at 3 months postoperatively,and 2.18±3.42D at 1 year postoperatively,the difference was statistically significant(P <0.05).CONCLUSION:The scleral flap made along the flattest meridian,under which the posterior chamber intraocular lenses(PCIOL) were sulcus-fixed by trans-scleral suture,can steepen the cornea in varying degrees,thus reducing preexisting corneal astigmatism.
