Healing characteristics of acellular porcine corneal stroma following therapeutic keratoplasty

Abstract

Background: Acellular porcine corneal stroma (APCS) has proven to be a promising alternative to traditional corneal grafts. This prospective case series was conducted to further investigate the healing characteristics of APCS following keratoplasty. Methods:Twenty-seven patients undergoing APCS implantation to treat infectious keratitis were included. The patients were followed up for 12 months after surgery.The main outcome measures included visual acuity, corneal transparency, graft thickness, and cellular and nerve regeneration. Results:In the operated eyes, the best-corrected visual acuity (BCVA, in logarithm of the minimal angle of resolution [logMAR] units) increased from 1.23 ± 0.95 log-MAR before surgery to 0.23 ± 0.18 logMAR at 12 months after surgery (P < .001).The contrast sensitivity was still evidently reduced, especially at higher spatial frequencies. Gradual transparency improvement was observed in APCS grafts postoperatively. After implantation, the APCS graft thickness initially increased (day 1 = 592.41 ± 52.69 µm) but then continuously decreased until 3 months after surgery (1 month = 449.26 ± 50.38 µm; 3 months = 359.63 ± 34.14 µm, P < .001). Graft reepithelialization was completed within 1 week. In the in vivo confocal microscopy scans, host keratocytes began to repopulate the APCS grafts between 3 and 6 months postoperatively; subbasal nerve regeneration was only noted in 18.52% (5/27) of the eyes by 12 months after surgery. Conclusions:Acellular porcine corneal stroma functions as an effective alternative to human corneal tissue in lamellar keratoplasty. However, APCS is somewhat different from fresh human cornea in term of the post-operative healing process, which warrants the attention of both clinicians and patients. K E Y W O R D Sacellular porcine corneal stroma, infectious keratitis, therapeutic keratoplasty

Effect of porcine corneal stromal extract on keratocytes from SMILE‐derived lenticules

“…Porcine corneas have been successfully used for corneal xenotransplantation over the past decade 41 . Li et al 42 reported that keratocytes started to repopulate from human recipient tissue into the acellular porcine corneal stroma between 3 and 6 months post‐operatively via proliferation and migration. The results clinically indicated that ECM components of porcine corneas encourage human keratocyte ingrowth and demonstrated good biological stability.…”

Corneal xenotransplantation: Where are we standing?

“…To date, DPC was approved to be used for LKP only by the Chinese National Institutes for Food and Drug Control in 2015 ( Shi and Xie, 2016 ). Three clinical trials and one case report using DPC in China have been published; all the studies were performed using the same commercially available DPC products ( Li et al, 2019 , 2020 ; Shi et al, 2017 ; Zhang et al, 2015 ; Zheng et al, 2019 ). The DPC was decellularized by hypertonic NaCl-ultrapure water alternating treatments, preserved in glycerol, and sterilized by 60 Co irradiation ( Zheng et al, 2019 ).…”

“…In the third clinical trial, 39 patients with progressive infectious keratitis underwent ALK using DPC for a 12 month-follow up. Twelve patients (30.8%) showed graft failure associated with herpetic keratitis and a graft size larger than 8.0 mm ( Li et al, 2019 , 2020 ). In a case report, DPC tissue was transplanted in a patient with a corneal ulcer and histology showed minimal infiltration of the inflammatory cells and migration of recipient's stromal cells.…”

Engineering a Corneal Stromal Equivalent Using a Novel Multilayered Fabrication Assembly Technique

“…2,3 However, these acellular scaffolds are composed of densely packed collagen lamellae, and thus recellularization is difficult, making it slow, both in vitro 4 and in vivo. 5 In attempts to improve recellularization, human lenticules extracted during myopia correction surgeries have been attached together using a fibrin glue hydrogel to prepare a decellularized scaffold. 6 Although the decellularized lenticules did populate with a small number of cells, the phenotype of these was not characterized.…”