Survival of corneal nerve/sheath structures in organ-cultured donor corneas

Dhillon, Virinder K.; Elalfy, Mohamed S.; Messina, Marco; Al-Aqaba, Mouhamed; Dua, Harminder S.

Abstract

Purpose
To study the morphology of human corneal nerves in eye bank organ‐cultured corneas and in corneal grafts post‐transplantation.

Methods
Thirty‐seven organ‐cultured corneas were divided into: Group‐A, anterior 300–400 μm of 20 corneas used for Descemets stripping endothelial keratoplasty, and Group‐B, 17 full‐thickness corneas unsuitable for transplantation. Corneas whole mounts were stained for nerves using acetylcholinesterase technique and examined by NanoZoomer digital pathology microscope. Central and sub‐Bowman's stromal nerves and the sub‐basal nerve plexus including perforation sites and terminal bulbs were studied. Ten eyes were imaged following penetrating keratoplasty using in‐vivo confocal microscopy (IVCM) for the presence of sub‐basal and stromal nerves at 1, 4–5 and 7–8 weeks postoperatively (five eyes) and in all the other five eyes, the final follow‐up was at 12 weeks.

Results
Fifteen of twenty (75%) corneas had stromal nerves in Group‐A and 15 of 17 (88.2%) in Group‐B. Average number of stromal nerves entering peripherally were 9.1 (range: 1–36). 7.5 in Group‐A and 10.8 in Group‐B. Central stromal nerves were seen in eight samples in Group‐A and nine in Group‐B. Many stromal nerves terminated abruptly without demonstrable continuity through Bowman's membrane. No terminal bulbs or sub‐basal nerves were detected. In‐vivo confocal microscopy (IVCM) showed 4 of 5 in 9 of 10 (90%) donor corneas had stromal nerves 1 week postoperatively, which remained present in 8 of 10 (80%) corneas at 4–5 weeks and in 9 of 10 (90%) at 7–8 weeks postoperatively. All 5 corneas analysed at 12 weeks showed the same stromal nerves from 1 to 12 weeks postoperatively. Sub‐basal nerves were absent in all corneas over the 12‐week study period.

Conclusion
This study provides further insight into the behaviour of corneal nerves in transplanted corneas. Corneal stromal nerves/nerve–sheaths are preserved in organ‐cultured eye bank eyes and persist post‐transplantation up to 3 months. These could provide directional guidance to regenerating nerves from host stroma.

• Journal Article Type: Article
• Acceptance Date: Sep 2, 2017
• Online Publication Date: Nov 29, 2017
• Publication Date: May 15, 2018
• Deposit Date: Feb 12, 2018
• Print ISSN: 1755-375X
• Electronic ISSN: 1755-3768
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• Volume: 96
• Issue: 3
• Pages: e334-e340
• DOI: https://doi.org/10.1111/aos.13614
• Keywords: corneal nerves; corneal transplant; eye bank; in vivo confocal microscopy
• Public URL: https://nottingham-repository.worktribe.com/output/1127262
• Publisher URL: https://onlinelibrary.wiley.com/doi/full/10.1111/aos.13614
• PMID: 29193851