Although its high successability in numerous corneal diseases, penetrating keratoplasty in certain conditions, such as chemical burn, ocular pemphigoid, Stevens-Johnson syndrome, severe dry eye, and recurrent graft rejection still has had poor outcomes. So far, many keratoprostheses have been developed, but none of them showed consistent successful results. The authors made two models of keratoprosthesis using expanded polytetrafluoroethylene (PTFE) as a skirt and these models were implanted to 30 and 5 rabbit corneas by intralamellar fixation respectively. Expanded PTFE was well-known for its biocompatibility and porous structure which fibrovascular tissue can grow in. However, both of the models extruded from the cornea in all cases and retention period was 1 month in average. These poor results are thought to be mainly due to previously known enzymatic degradation. To obtain better result, modification of the models and surgical techniques are needed. Several possible modifications are described in this article.
Burns, Chemical ; Cornea ; Corneal Diseases ; Graft Rejection ; Keratoplasty, Penetrating ; Pemphigoid, Bullous ; Polytetrafluoroethylene ; Stevens-Johnson Syndrome

For many years it has been known that the dosage of thiopental required to induce anesthesia depends on the age of the patient, but this information ha resulted from clinical experience with the drugs rather than from planned study. In our study, to elucidate the influence of age on the size of the sleeping dosage of thiopental, 144 patients who underwent minor orthopedic and gynecological operations were studied. This patients had no evidence of a disease other than that scheduled for operation and were within normal values in hematologic examination, liver function and kidney function. Using a simple "yes" or "no" verbal command response, as sleeping response, to a single bolus of thiopental in mg/kg body weight, we have attemted to minimize uncontroliable factors such as cerebral perfusion, circulation time and plasma protein binding which would alter response to thiopental infusions continued to the end points. The results were as follows: 1) There was no statistical difference in verbal command response to thiopental according to age in age groups below 59 years. 2) Compared with age groups below 59 years, 60~79yrs, group failed to respond to the verbal command in 33% by 2.2mg/kg and 100% by above 2.6mg/kg.(p<0.05) 3) The mean time for loss of verbal command response after thiopental injection was 27.4+/-10.3 seconds and 80.4% of theses patients lost lid reflex with a mean time of 41.7+/-9.1 seconds after thiopental injection. 4) All groups showed statistically non-significant alterations of systolic blood pressure and heart rate after injection of thiopental.
Anesthesia ; Blood Pressure ; Body Weight ; Heart Rate ; Humans ; Kidney ; Liver ; Orthopedics ; Perfusion ; Plasma ; Protein Binding ; Reference Values ; Reflex ; Thiopental*