In vivo confocal microscopy study of corneal nerve alterations in children and youths with Type 1 diabetes

Abstract

Objective To determine whether children and youths with Type 1 diabetes (T1D) have early alterations of the corneal subbasal nerve plexus detectable with in vivo confocal microscopy (IVCM) and to investigate the role of longitudinally measured major risk factors for diabetes complications associated with these alterations. Methods One hundred and fifty children and youths with T1D and 51 age‐matched controls were enrolled and underwent IVCM. Corneal nerve fiber length (CNFL), corneal nerve fiber density (CNFD), corneal nerve branch density (CNBD), corneal fiber total branch density (CTBD), and corneal fiber fractal dimension (CNFrD) were measured. Risk factors for diabetes complications (blood pressure, BMI, HbA1c, lipoproteins, urinary albumin‐creatinine ratio) were recorded at IVCM and longitudinally since T1D onset. Unpaired t ‐test was used to compare variables between the groups. Multiple regression models were calculated using IVCM parameters as dependent variables and risk factors as independent variables. Results All IVCM parameters, except CTBD, were significantly lower in the T1D patients. Glycometabolic control (HbA1c, visit‐to‐visit HbA1c variability, and mean HbA1c), and blood pressure were inversely correlated with IVCM parameters. Multiple regression showed that part of the variability in CNFL, CNFD, CTBD, and CNFraD was explained by HbA1c, blood pressure percentiles and age at IVCM examination, independent of diabetes duration, BMI percentile and LDL cholesterol. Comparable results were obtained using the mean value of risk factors measured longitudinally since T1D onset. Conclusions Early signs of corneal nerve degeneration were found in children and youths with T1D. Glycometabolic control and blood pressure were the major risk factors for these alterations.

Treatment‐induced neuropathy of diabetes in an adolescent with rapid reduction in HbA1c and weight loss: Persistent neuropathic findings at follow‐up after 1.5 years

“… 18 Values were CNFL 9.86 mm/mm 2 , CNFD 16.7 n/mm 2 , CNBD 10.4 n/mm 2 , CTBD 16.7 n/mm 2 , and CNFrD 1.44, respectively (Image of nerves in cornea Figure 1C ). Compared to healthy controls, these values are low 19 indicating small fiber neuropathy.…”

Assessing the corneal sub-basal nerve plexus by in vivo confocal microscopy in patients with blepharoptosis

“…Corneal nerve fractal dimension (CNFrD) is a newly developed IVCM parameter obtained with employment of the latest version of ACCMetrics program [ 25 , 26 ]. CNFrD indicates the structural complexity of corneal nerve fibres, which could be useful as an alternative means to identify patients with neuropathies of various causes.…”

Early marker of ocular neurodegeneration in children and adolescents with type 1 diabetes: the contributing role of polymorphisms in mir146a and mir128a genes

“…Inc.) were performed in both eyes and for each parameter the mean of right and left eyes measurements was calculated. All the examinations were performed by the same expert operator (TC) as previously described [ 5 , 6 ].…”

“…In recent years, two new ophthalmologic imaging techniques, Spectral domain-optical coherence tomography (SD-OCT) and In vivo confocal microscopy (IVCM), emerged for their ability to identify early neurodegenerative changes in retina and cornea of subjects with diabetes [ 4 ]. Concerning the evaluation of these early ocular changes during the pediatric age, we demonstrated that a significant impairment of the minimum neuroretinal rim width (MRW) of the optic nerve head (ONH) measured with SD-OCT and of the corneal subbasal nerve plexus (SBP) measured with IVCM is present in T1D children and adolescents compared with age and gender-matched controls [ 5 , 6 ]. Our results also showed that long-term glycometabolic control and blood pressure partially predicted the presence of early damage signs, in agreement with recent findings that recognized glycemic control and hypertension as major risk factors for DN development and progression [ 2 ].…”