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. 2021 Jan 4;62(1):20.
doi: 10.1167/iovs.62.1.20.

Corneal Keratocyte Density and Corneal Nerves Are Reduced in Patients With Severe Obesity and Improve After Bariatric Surgery

Zohaib Iqbal  1   2 , Alise Kalteniece  1   2 , Maryam Ferdousi  1   2 , Safwaan Adam  1 , Luca D'Onofrio  3 , Jan H Ho  1   2 , Anoop Prasanna Rao  1 , Shaishav Dhage  1   2 , Shazli Azmi  1   2 , Yifen Liu  1 , Rachelle Donn  1 , Rayaz A Malik  1   4 , Handrean Soran  1   2
Affiliations

Corneal Keratocyte Density and Corneal Nerves Are Reduced in Patients With Severe Obesity and Improve After Bariatric Surgery

Zohaib Iqbal et al. Invest Ophthalmol Vis Sci. .

Abstract

Purpose: Obesity is associated with peripheral neuropathy, which bariatric surgery may ameliorate. The aim of this study was to assess whether corneal confocal microscopy can show a change in corneal nerve morphology and keratocyte density in subjects with severe obesity after bariatric surgery.

Methods: Twenty obese patients with diabetes (n = 13) and without diabetes (n = 7) underwent assessment of hemoglobin A1c (HbA1c), lipids, IL-6, highly sensitive C-reactive protein (hsCRP), and corneal confocal microscopy before and 12 months after bariatric surgery. Corneal nerve fiber density (CNFD), corneal nerve branch density (CNBD), corneal nerve fiber length (CNFL), and keratocyte density (KD) from the anterior, middle, and posterior stroma were quantified. Twenty-two controls underwent assessment at baseline only.

Results: CNFL (P < 0.001), CNBD (P < 0.05), and anterior (P < 0.001), middle (P < 0.001), and posterior (P < 0.001) keratocyte densities were significantly lower in obese patients compared to controls, and anterior keratocyte density (AKD) correlated with CNFL. Twelve months after bariatric surgery, there were significant improvements in body mass index (BMI; P < 0.001), HDL cholesterol (P < 0.05), hsCRP (P < 0.001), and IL-6 (P < 0.01). There were significant increases in CNFD (P < 0.05), CNBD (P < 0.05), CNFL (P < 0.05), and anterior (P < 0.05) and middle (P < 0.001) keratocyte densities. The increase in AKD correlated with a decrease in BMI (r = -0.55, P < 0.05) and triglycerides (r = -0.85, P < 0.001). There were no significant correlations between the change in keratocyte densities and corneal nerve fiber or other neuropathy measures.

Conclusions: Corneal confocal microscopy demonstrates early small fiber damage and reduced keratocyte density in obese patients. Bariatric surgery leads to weight reduction and improvement in lipids and inflammation and an improvement in keratocyte density and corneal nerve regeneration.

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Conflict of interest statement

Disclosure: Z. Iqbal, None; A. Kalteniece, None; M. Ferdousi, None; S. Adam, None; L. D'Onofrio, None; J.H. Ho, None; A.P. Rao, None; S. Dhage, None; S. Azmi, None; Y. Liu, None; R. Donn, None; R.A. Malik, None; H. Soran, None

Figures

Figure 1.
Figure 1.
CCM images of sub-basal nerve plexus (A1–A3) and anterior (B1–B3), middle (C1–C3), and posterior (D1–D3) stromal keratocytes in healthy controls (A1–D1) and obese patients before (A2–D2) and after (A3–D3) bariatric surgery.
Figure 2.
Figure 2.
Error plots showing mean and SEM of anterior, middle, and posterior keratocyte densities in controls and obese patients at baseline and 12 months. *P < 0.05.
Figure 3.
Figure 3.
Error plots showing mean (SEM) of CNFD, CNBD, and CNFL in controls and obese patients at baseline and 12 months after bariatric surgery. *P <0.05.
Figure 4.
Figure 4.
Correlation plots among clinical, metabolic, and inflammatory markers with CCM markers.
See this image and copyright information in PMC

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