Corneal confocal microscopy detects early nerve regeneration after pancreas transplantation in patients with type 1 diabetes.
OBJECTIVE
Corneal confocal microscopy (CCM) is a rapid, noninvasive, clinical examination technique that quantifies small nerve fiber pathology. We have used it to assess the neurological benefits of pancreas transplantation in type 1 diabetic patients.


METHODS
In 20 patients with type 1 diabetes undergoing simultaneous pancreas and kidney transplantation (SPK) and 15 control subjects, corneal sensitivity was evaluated using noncontact corneal esthesiometry, and small nerve fiber morphology was assessed using CCM.


RESULTS
Corneal sensitivity (1.54 +/- 0.28 vs. 0.77 +/- 0.02, P < 0.0001), nerve fiber density (NFD) (13.8 +/- 2.1 vs. 42 +/- 3.2, P < 0.0001), nerve branch density (NBD) (4.04 +/- 1.5 vs. 26.7 +/- 2.5, P < 0.0001), and nerve fiber length (NFL) (2.23 +/- 0.2 vs. 9.69 +/- 0.7, P < 0.0001) were significantly reduced, and nerve fiber tortuosity (NFT) (15.7 +/- 1.02 vs. 19.56 +/- 1.34, P = 0.04) was increased in diabetic patients before pancreas transplantation. Six months after SPK, 15 patients underwent a second assessment and showed a significant improvement in NFD (18.04 +/- 10.48 vs. 9.25 +/- 1.87, P = 0.001) and NFL (3.60 +/- 0.33 vs. 1.84 +/- 0.33, P = 0.002) with no change in NBD (1.38 +/- 0.74 vs. 1.38 +/- 1.00, P = 1.0), NFT (15.58 +/- 1.20 vs. 16.30 +/- 1.19, P = 0.67), or corneal sensitivity (1.23 +/- 0.39 vs. 1.54 +/- 00.42, P = 0.59).


CONCLUSIONS
Despite marked nerve fiber damage in type 1 diabetic patients undergoing pancreas transplantation, small fiber repair can be detected within 6 months of pancreas transplantation using CCM. CCM is a novel noninvasive clinical technique to assess the benefits of therapeutic intervention in human diabetic neuropathy.
Mehra
Sanjay
S
Transplant Unit, Manchester Royal Infirmary, Manchester, UK.
Tavakoli
Mitra
M
Kallinikos
Panagiotis A
PA
Efron
Nathan
N
Boulton
Andrew J M
AJ
Augustine
Titus
T
Malik
Rayaz A
RA
D003315:Cornea / Q000166:cytology / Q000294:innervation* / Q000473:pathology*; D003922:Diabetes Mellitus, Type 1 / Q000601:surgery*; D003930:Diabetic Retinopathy / Q000503:physiopathology*; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D018613:Microscopy, Confocal; D009412:Nerve Fibers / Q000473:pathology; D009416:Nerve Regeneration; D016035:Pancreas Transplantation / Q000502:physiology*; D012016:Reference Values
D006442:Glycated Hemoglobin