Variation Of Corneal Endothelial Cells With Penetrating Keratoplasty

Purpose: To investigate changes in the human corneal endothelium of donor eyeballs and postoperative grafts with advanced wild-field specular microscope.Methods: Endothelial cell density (BCD), average cell area, coefficient of variation of cell area (CV) and percentage of hexagonal cell were compared for 24 donor corneas that underwent a penetrating keratoplasty. The preoperative data were compared with those obtained in postoperative 2-6 weeks, 3-6 months, 7-11 months and 1-1.5 years. The data were compared for 15 eyes that underwent the penetrating keratoplasty and 9 eyes that underwent penetrating keratoplasty which combined other operation. The factors which impacted on variation of corneal endothelium were analyzed. The corneal thickness of donor eyeballs and postoperative grafts were measured to evaluate the effectiveness of operation.Results: (1) The loss rates of the corneal endothelium were 12.17%, 21.91%, 26.55% and 29.28% in postoperative 2-6 weeks, 3-6 months, 7-11 months and 1-1.5 years respectively. The results showed that the loss rates increased largely in postoperative 3-6 months, but after 7-11 months evenly. (2) The average cell area of the donor corneal endothelium increased from preoperative 4567.06μm2 to 646.34μm2in 1-1.5 years postoperatively. The CV increased from 52.42% to 62.32%. (3) The percentage of hexagonal cells of donor corneal endothelium decreased from 41.74% to 28.08% after operation 1-1.5 years. (4) The loss rates of corneal endothelium were 25.30% and 33.50% in the penetrating keratoplasty and penetrating keratopolasty combined other operation respectively, there was statistically significant difference(P<0.05).The average cell area increase 84.98μm2and 285.86pm2 in two groups respectively, there was statistically significant difference (P<0.01). The CV of two groups increase 3.85% and 16.02% respectively, there was statistically significant difference(P<0.05). The percentage of standard hexagonal cell decreased 4.87% and 21.86% respectively, there was statistically significant difference (P0.05). The thickness of grafts in two groups were 489.73μm and 513.76μm after operation 1.5 years, there was no statistically significant difference(P<0.05).Conclusion: (1) After penetrating keratoplasty, the density of donor corneal endothelium decreased, but the loss rates of corneal endothelium increased especially after operation 3-6 months, and did less postoperatively 7-11 months. The average cell area and CV increased gradually. The percentage of standard hexagonal cells decreased and the non-hexagonal cells increased. (2) The loss rates of the corneal endothelium was higher, the average area and CV increased more significantly and the percentage of standard hexagonal cells decreased more significantly on the PKP combined other operations than PKP alone. Trauma in the operation and intraocular inflammatory reaction postoperatively both were important factors on influencing variation of donor corneal endothelial cells. (3)A11 grafts were transparent, and corneal thickness was in the normal range, and had good correct acuity vision on penetrating keratoplasty and PKP combined operation. So that this operation is important means for treating corneal leucoma and other diseases.