Predicting endothelial cell loss and long-term corneal graft survival.

نویسندگان

  • W John Armitage
  • Andrew D Dick
  • William M Bourne
چکیده

PURPOSE To evaluate a biexponential decay model for describing the loss of corneal endothelial cells with age as well as the increased loss of cells after cataract surgery and penetrating keratoplasty. METHODS Data from previous studies were identified and the sum of two exponentials, d = p. exp(-at) + q. exp(-bt) (where d is cell density at time t, p and q are constants the sum of which is equal to the initial cell density, and a and b are exponential rate constants), fitted to each data set by a nonlinear least-squares algorithm. Goodness of fit was indicated by the residual standard deviation. Half times were calculated from the exponential rate constants. RESULTS The model identified in each instance a rapid and a slow component to the cell loss. The half time for the slow component of the loss with age was 224 years, underlining the excess endothelial capacity in normal eyes. After surgery, the rapid component of the cell loss was probably due to surgical trauma and, after penetrating keratoplasty, cell-mediated rejection and other complications. The half times of the slow component were only 26 years after cataract surgery and 21 years after penetrating keratoplasty. DISCUSSION The loss of endothelial cells followed a biexponential decay and could thus be described by a single equation. The half times of the slow component of the cell loss after surgery were substantially less than for the loss with age, indicating a markedly increased rate of cell loss that persisted for many years after surgery. A mechanism for this accelerated cell loss is suggested that involves a nonspecific, innate response initiated by the breakdown of the blood-ocular barrier. The model was used to calculate endothelial cell loss in the long term after penetrating keratoplasty and to predict when cell density would reach levels that are incompatible with maintenance of transparency and graft function. Thus, a rationale is presented for the setting of minimum donor cell densities by eye banks.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Long-term Outcome of Limbal Stem Cell Transplantation for the Management of Total Limbal Stem Cell Deficiency due to a Chemical Burn

Purpose: To evaluate the long-term outcome of limbal stem cell transplantation (LSCT) for the management of total limbal stem cell deficiency (LSCD) due to chemical burn in Labbafinejad Medical Center (LMC). Methods: Records of patients with a history of severe (i.e. grade III and IV) chemical burns, who were referred to LMC and underwent LSCT, were reviewed and data including demographic chara...

متن کامل

Factors associated with graft survival and endothelial cell density after Descemet’s stripping automated endothelial keratoplasty

Postoperative endothelial cell loss leads to graft failure after corneal transplantation, and is one of the important issues for long-term prognosis. The objective of this study was to identify clinical factors affecting graft survival and postoperative endothelial cell density (ECD) after Descemet's stripping automated endothelial keratoplasty (DSAEK). A total of 198 consecutive Japanese patie...

متن کامل

Long-term survival of endothelium following transplantation of corneas stored by organ culture.

This study reports corneal graft survival, endothelial cell changes, and visual outcome in 20 patients who received some of the first corneas stored by organ culture in the Corneal Transplant Service Eye Bank in Bristol. Mean donor age was 48 years (SD 15, n = 20) and corneas were stored for an average of 21 days (SD 7, n = 20). Preoperative endothelial cell density was 2334 cells/mm2 (SD 235, ...

متن کامل

Effect of Fas -670 A/G Gene Polymorphism on Corneal Allograft Endothelial Rejection

Background: Human cornea expresses functional Fas-ligand capable of killing Fas+ activated lymphocytes. Fas expression is partly regulated by -670 A/G polymorphism in the promoter region of Fas gene. Objective: The aim of the present study is to determine the association between Fas-670A/G polymorphism and survival of corneal transplantation. Methods: In 276 graft recipients who mainly underwen...

متن کامل

Survival of donor-derived cells in human corneal transplants.

PURPOSE To determine the fate of donor epithelial, stromal, and endothelial cells after corneal transplantation in humans. METHODS Fifty-two transplanted corneal buttons were explanted over a 2-year period from patients who required regrafting and had received corneas from donors of opposite sex. Fluorescence in situ hybridization of the sex chromosomes of the epithelial, stromal, and endothe...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:
  • Investigative ophthalmology & visual science

دوره 44 8  شماره 

صفحات  -

تاریخ انتشار 2003