Analysis of risk factors of rapid attenuation of graft endothelium in the early stage after penetrating keratoplasty

Abstract

This study aimed to analyze the factors of rapid attenuation of graft endothelium in the early stage after penetrating keratoplasty (PKP), with a view to guiding patients with PKP to better long-term outcomes. This study included 226 patients who underwent PKP with follow-up time >1 year at the Qingdao Eye Hospital of Shandong First Medical University from January 2018 to June 2020. Medical records were retrospectively studied, and donor factors, patient factors, and surgical factors were comparatively analyzed to clarify those affecting the rapid decay of graft endothelium after PKP. The median time between excision and death >60 min and patient age >60 years were risk factors for endothelial cell loss (ECL) rate >30% at 1 month postoperatively. However, a higher percentage of patients with donor age ≤60 years and Optisol preservation solution had endothelial cell density (ECD) >2000 cells/mm2 in the graft at postoperative 1 year. A year after the surgery, patients with corneal endothelial decompensation and immune rejection were at risk for ECD < 1000 cells/mm2. The combined operations had a significant effect on the ECL in the early postoperative period. Patients who underwent combined extracapsular cataract extraction or intraocular lens implantation had a significantly higher rate of ECL at postoperative 1 month than other patients, and no significant effect at postoperative 1 year. However, patients without combined operations have a higher probability of maintaining a high level of graft ECD. The graft diameter also affected postoperative ECL. In patients with a larger graft diameter, attenuation of ECD was slower. The ultimate goal of PKP is to maintain graft transparency for extended periods. The use of younger donors, minimizing unnecessary operation in the anterior chamber, and minimizing immune rejection may maintain a greater donor corneal endothelium in the long term.

Risk Factors for Corneal Endothelial Decompensation after Penetrating Keratoplasty: A Population-Based Cohort Study

“…Furthermore, endothelial decompensation and graft failure accounted for up to 10 percent of patients who received PK surgery [15]. Risk factors related to post-KP endothelial cell loss have been previously identified [10][11][12][13][14]24,25], and the concept is also supported by the findings of the present study.…”

“…In this study, patients with pre-existing T2DM and a history of cataract surgery showed a higher incidence of post-PK endothelial decompensation compared to the individuals without these conditions. In a previous study, the risk factors for post-PK endothelial decompensation included a longer death-to-excision time of donor cornea, lower ECD, previous T2DM history of the donor, and old age [14,24,25]. However, whether the diseases of the recipient alter the risk of post-PK endothelial decompensation has not been fully investigated.…”

“…A history of cataract surgery showed similar and significant associations with post-PK endothelial decompensation in the sex subgroups, while the correlation between a history of cataract surgery and post-PK endothelial decompensation was not prominent in the patients aged younger than 60 years. A possible reason may be that patients younger than 60 years old usually have softer cataracts which require less phaco-power, thus generating less oxidative stress in endothelial cells, and old age itself is a significant risk factor for endothelial loss and decompensation [24,52]. Consequently, younger patients demonstrate better endothelial recovery from cataract surgery [30], and the risk of post-PK endothelial decompensation is relatively lower in such a population compared to the elderly.…”

“…From studies performed more than 25 years ago, endothelial decompensation after PK has been associated with factors, such as immune rejections, low endothelial cell density at 2 months post-surgery, aphakia or pseudophakia, and older recipient and donor age, among others [7,22,23]. A recent study also showed that old age and lower endothelial cell density (ECD) were risk factors for endothelial decompensation after PK surgery [24]. Additionally, graft size and a history of type 1 diabetes mellitus, as well as type 2 diabetes mellitus (T2DM), in donors correlated to the development of post-PK endothelial decompensation [25].…”

Combined versus sequential penetrating keratoplasty and cataract surgery for herpes simplex keratitis: a retrospective study

“…Endothelial cell decompensation is a frequently observed postoperative complication for late graft failure (24). Endothelial cell loss rate for non-inflammatory corneal diseases reported in the literature is varied after PK, ranging from 20.3 to 22.5% at 6 months (25-27), reaches the highest loss rate approximately at 40% in the first year, and then decreases gradually during the subsequent follow-up (28,29). However, other studies have reported that the average corneal endothelial cell loss rate can reach 75% at 5 years after PK (30).…”