Early Alterations of Corneal Subbasal Plexus in Uncomplicated Type 1 Diabetes Patients

Purpose. The purpose of our study is to describe the in vivo corneal confocal microscopy characteristics of subbasal nerve plexus in a highly selected population of patients affected by type 1 diabetes mellitus (T1DM) without any microvascular diabetes complications.Methods. We included 19 T1DM patients without diabetic peripheral neuropathy, diabetic autonomic neuropathy, diabetic retinopathy, and microalbuminuria. All patients underwent in vivo corneal confocal microscopy and blood analysis to determine subbasal nerve plexus parameters and their correlation with clinical data. We compared the results with 19 healthy controls.Results. The T1DM group showed a significant decrease of the nerve fiber length (P=0.032), the nerve fiber length density (P=0.034), the number of fibers (P=0.005), and the number of branchings (P=0.028), compared to healthy subjects. The nerve fiber length, nerve fiber length density, and number of fibers were directly related to the age at onset of diabetes and inversely to the duration of DM. BMI (body mass index) was highly related to the nerve fiber length (r = −0.6,P=0.007), to the nerve fiber length density (r = −0.6,P=0.007), and to the number of fibers (r = −0.587,P=0.008). No significant correlations were found between the corneal parameters and HbA1c.Conclusions. Early subclinical fiber corneal variation could be easily detected using in vivo corneal confocal microscopy, even in type 1 diabetes without any microvascular diabetes complications, including diabetic peripheral neuropathy, diabetic autonomic neuropathy, diabetic retinopathy, and microalbuminuria.

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Corneal confocal microscopy shows progressive reduction in corneal nerve fiber length over a 2 year time period in children with type 1 diabetes

Journal of American Association for Pediatric Ophthalmology and Strabismus ◽

10.1016/j.jaapos.2018.07.041 ◽

2018 ◽

Vol 22 (4) ◽

pp. e13

Author(s):

Stephanie A. Dotchin ◽

Heidi T. Virtanen ◽

Kenneth G. Romanchuk ◽

Daniele Pacaud ◽

Alberto Nettel-Aguirre ◽

...

Keyword(s):

Type 1 Diabetes ◽

Confocal Microscopy ◽

Nerve Fiber ◽

Fiber Length ◽

Progressive Reduction ◽

Time Period ◽

Corneal Confocal Microscopy ◽

Corneal Nerve

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Combining In Vivo Corneal Confocal Microscopy with Deep Learning-based Analysis Reveals Sensory Nerve Fiber Loss in Acute SIV Infection

10.1101/2020.04.19.048926 ◽

2020 ◽

Author(s):

Megan E. McCarron ◽

Rachel L. Weinberg ◽

Jessica M. Izzi ◽

Suzanne E. Queen ◽

Stuti L. Misra ◽

...

Keyword(s):

Fractal Dimension ◽

Deep Learning ◽

Confocal Microscopy ◽

Nerve Fiber ◽

Fiber Length ◽

Sensory Nerve ◽

Corneal Confocal Microscopy ◽

Siv Infection ◽

Corneal Nerve

AbstractPurposeTo characterize corneal subbasal nerve plexus morphologic features using in vivo corneal confocal microscopy (IVCM) in normal and SIV-infected macaques and to implement automated assessments using novel deep learning-based methods customized for macaque studies.MethodsIn vivo corneal confocal microscopy images were collected from both male and female age-matched specific-pathogen free rhesus and pigtailed macaques housed at the Johns Hopkins University breeding colony using the Heidelberg HRTIII with Rostock Corneal Module. We also obtained repeat IVCM images of 12 SIV-infected animals including pre-infection and 10 day post-SIV infection time-points. All IVCM images were analyzed using a novel deep convolutional neural network architecture developed specifically for macaque studies.ResultsDeep learning-based segmentation of subbasal nerves in IVCM images from macaques demonstrated that corneal nerve fiber length (CNFL) and fractal dimension measurements did not differ between species, but pigtailed macaques had significantly higher baseline corneal nerve fiber tortuosity than rhesus macaques (P = 0.005). Neither sex nor age of macaques was associated with differences in any of the assessed corneal subbasal nerve parameters. In the SIV/macaque model of HIV, acute SIV infection induced significant decreases in both corneal nerve fiber length and fractal dimension (P= 0.01 and P= 0.008 respectively).ConclusionsThe combination of IVCM and objective, robust, and rapid deep-learning analysis serves as a powerful noninvasive research and clinical tool to track sensory nerve damage, enabling early detection of neuropathy. Adapting the deep-learning analyses to human corneal nerve assessments will refine our ability to predict and monitor damage to small sensory nerve fibers in a number of clinical settings including HIV, multiple sclerosis, Parkinson’s disease, diabetes, and chemotherapeutic neurotoxicity.

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