Corneal diabetic neuropathy: a confocal microscopy study.
OBJECTIVE
To evaluate the role of corneal confocal microscopy in the diagnosis of morphologic damage of the corneal sub-basal nerve plexus in diabetic patients and to correlate corneal confocal microscopy findings with peripheral diabetic neuropathy.


METHODS
Corneal sub-basal nerve plexus parameters were quantified by corneal confocal microscopy in 42 diabetic patients and 27 age-matched controls. The parameters quantified were the number of fibers, the tortuosity of fibers, the number of beadings, and the branching pattern of the fibers. Peripheral neuropathy was also quantified using the Michigan Neuropathy Screening Instrument.


RESULTS
The number of fibers, number of beadings, and branching pattern of fibers significantly decreases in diabetic patients versus control subjects (P<.0001; P<.0001; P=.0006, respectively), whereas nerve tortuosity significantly increases (P<.0001). The same corneal sub-basal nerve plexus parameters show a statistical trend, suggesting progression of corneal neuropathy with peripheral diabetic neuropathy.


CONCLUSIONS
Corneal confocal microscopy represents a new tool in the diagnosis, clinical evaluation, and follow-up of peripheral diabetic neuropathy. This study found that diabetes damages corneal nerves, particularly the corneal sub-basal nerve plexus. This damage may be easily and accurately documented using corneal confocal microscopy.
Midena
Edoardo
E
Department of Ophthalmology, University of Padova, Italy. edoardo.midena@unipd.it
Brugin
Erica
E
Ghirlando
Alessandra
A
Sommavilla
Marco
M
Avogaro
Angelo
A
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003315:Cornea / Q000294:innervation* / Q000473:pathology; D003316:Corneal Diseases / Q000209:etiology / Q000473:pathology*; D003929:Diabetic Neuropathies / Q000150:complications / Q000473:pathology*; D018450:Disease Progression; D005260:Female; D006801:Humans; D008297:Male; D018613:Microscopy, Confocal / Q000379:methods; D008875:Middle Aged; D011379:Prognosis