ABSTRACT
<p><b>BACKGROUND</b>Descemet's stripping automated endothelial keratoplasty (DSAEK) surgery offers a more standardized approach and reliable method to create corneal grafts with an instrument such as a microkeratome. With the development of Descemet's membrane endothelial keratoplasty, an excellent clinical outcome is seen in the treatment of corneal endothelial dysfunctions, which indicates that thinner corneal graft results in better clinical outcome. With the recent development of the femtosecond laser, ultrathin corneal graft preparation has become possible. This study aimed to report corneal graft endothelial cell loss (ECL) in a large series of cases undergoing DSAEK with femtosecond laser-assisted corneal graft preparation within a 12-month period.</p><p><b>METHODS</b>This study was designed as a prospective, noncomparative, interventional case series. Totally 126 consecutive eyes with endothelial failure of 120 patients, who had corneal endothelial decompensation and underwent femtosecond-assisted DSAEK using the VisuMax femtosecond laser system, were included in the study. Central endothelial cell density (ECD) was recorded postoperatively at 2 weeks (n = 126), 1 month (n = 126), 3 months (n = 110), 6 months (n = 101), and 12 months (n = 71) and then compared with the preoperative eye bank measurements. Pre- and postoperative central ECDs were evaluated using Heidelberg retina tomography-III confocal microscopy. ECL was calculated for each postoperative time point. Graft thickness was examined using anterior segment-optical coherence tomography.</p><p><b>RESULTS</b>Mean preoperative cell count was 3383 ± 350 cells/mm2. Mean postoperative cell counts were 2382 ± 707 cells/mm2, 2179 ± 685 cells/mm2, 2074 ± 688 cells/mm2, 1884 ± 662 cells/mm2, and 1723 ± 624 cells/mm2 at 2 weeks, 1, 3, 6, and 12 months, respectively; these represented the ECL of 29.7 ± 19.7%, 35.4 ± 19.5%, 38.6 ± 19.8%, 44.3 ± 18.9%, and 48.9 ± 18.4% at the each corresponding time point. The mean corneal graft thickness after surgery was 142 ± 48 μm, 118 ± 41 μm, 108 ± 37 μm, 100 ± 32 μm, and 99 ± 32 μm at each corresponding study visit, respectively. There was no correlation between corneal graft thickness and corneal ECL (R = 0.039).</p><p><b>CONCLUSIONS</b>Corneal ECL remained relatively stable up to 12 months after femtosecond laser-assisted ultrathin DSAEK in a large case series. No correlation between cell loss and corneal graft thickness was found, which indicated that corneal graft preparation by the femtosecond laser was safe. ECL was faster within the first 6 months and relatively stable thereafter.</p>
ABSTRACT
Background Cyclosporine A (CsA) is an effective drug to prevent rejection response after penetrating keratoplasty (PKP).Appropriate dosage forms and right administrating route is very important for improving the bioavailability of CsA.Objective This study was to investigate the preventing effect of CsA microspheres via subconjunctive and anterior chamber injection and CsA eye drops on immune rejection after PKP.Methods Sixty eyes of 60 clean adult New Zealand white rabbits served as receipts,and 60 eyes of 30 clean adult pigmented rabbits were used as the donors.The receipts were randomized into the blank control group (only PKP group),subconjunctival CsA injection group,subconjunctival vector injection group,anterior chamber CsA injection group,anterior chamber vector injection group,and 1％ CsA eye drops group.PKP was performed on the all rabbits,and then the CsA microsphere (0.1 ml,12 g/L) or blank microsphere (0.1 ml) were respectively administered in the corresponding groups.The corneal grafts were examined by slit lamp microscope regularly,and rejection index (RI)was calculated based on the corneal opacity,edema and neovascularization.The intraocular pressure (IOP) of operative eyes was measured by Tono-pen tonometer before operation,3 days,1 week,2 weeks,3 weeks,1 month,2 months and 3 months after operation,respectively.Histopathological examination on corneal grafts was performed 1month and 3 months after operation.Results The IOP of all the rabbits lowed after operation,but there was no statistical difference in different time points and various groups (Ftime =29.210,P =0.000; Fgroup =0.254,P =0.938).The grafts of the blank control group,subconjunctival vector injection group and the anterior chamber vector injection group showed varied degrees of corneal opacity and neovascularization 2-3 weeks after operation,and the degree of graft opacity was aggravated obviously in the fourth week,with the RI 8.60±1.52,8.60±0.55 and 8.80±0.84 individually.Neovascularization of the grafts in the subconjunctival CsA injection group,anterior chamber CsA injection group,and 1％ CsA eye drops group was found 3 weeks after operation,and the RI were 4.40±0.89,3.20±0.84 and 3.00±0.71,showing a significantly lower than that of the control groups (P＜0.05).Mild inflammatory response of the grafts was seen in the anterior chamber CsA injection group,but it was lightened over time.The histopathological examination revealed obvious thickening of corneal grafts,neovascularization and infiltration of lots of inflammatory cells in the blank control group,subconjunctival vector injection group and the anterior chamber vector injection group.However,only slight new blood vessels and inflammatory response were seen on the subconjunctival CsA injection group,anterior chamber CsA injection group,and 1％ CsA eye drops group.Conclusions Administration of CsA in different methods can prevent the immune rejection after PKP in rabbit eyes,the effect of giving drugs via anterior chamber injection is better than that via subconjunctive pathyway.
ABSTRACT
Background The select of supporter is critical for the construction of tissue engineering cornea.Many carrier carl be utilized in the construction of tissue engineering cornea,but de-cellular corneal matrix is known to be one of optimal supporters.Objective Present study was to investigate the characteristics of de-cellular corneal matrix of porcine of structure and biocompatibility for rabbit cornea stroma and limbal epithelial ceHs. Methods The porcine cornea was prepared as de-cellular corneal matrix of porcine by the application of detergent enzyme combined process.The corneal epithelial cells,keratocyte and endothelial cells of porcine were removed completely and stored in -20℃ refrigerator after sterilization.The morphology of de-cellular corneal matrix of porcine was examined by hematoxylin-eosin staining under the light microscope.The structure characteristics of de.cellular corneal matrix of porcine under the scan electron microscope,and its physics features were investigated by the evaluation of water content,strength,expansion and transparency.The de-cellular corneal matrix of porcine were implanted to cornea stroma of rabbit and co-cultured with rabbit corneal epithelial cells for 4 weeks in vitro to assess the keracyte compatibility. Results The epithelial cells,keratocyte and endothelial cells of porcine were removed completely by trypsogen digestion.The collagen fibril network and collagen plates paralleled to corneal surface under the light microscope.The water content,strength,expansion。Ratio of light transparency of de-cellular corneal matrix of porcine were similar to normal porcine cornea.After implantation of de.cellular comeal matrix of porcine into rabbits corneal stroma,the edema of tissue was found in one week,and edema disappeared on two weeks and became clear on four weeks after surgery.The de-cellular eorneal matrix attached to rabbit cornea stroma well.No inflammatory eell and new vessel were found after surgery.The co-cultured rabbit corneal epithelial cells differentiated and proliferated on the surfaee of de-cellular corneal matrix and showed positive response for CK3.No statistically significant differences were found in the water content,strength,expansion of de-cellular cornea matrix of porcine among the normal,before dehydration,2 and 4 hours after dehydration cornea matrix(P＞0.05).However,the transparency was much better in the corneal matrix with 2-hour,4-hour dehydration in comparison with non-dehydration one(P＜0.05). Conclusion The structure features of de-cellular cornea matrix of porcine are similar to normal porcine cornea.Good biocompatibility is proved for xenogenesis of rabbit cornea.