Corneal Metrics Improve Following Bariatric Surgery

Optometrist examing patient's eyes
Optometrist examing patient’s eyes
A study shows that patients who lost weight after undergoing the procedure had an improved corneal sensitivity threshold.

This article is part of Optometry Advisor’s conference coverage from the 2021 meeting of the American Academy of Optometry, held in Boston from November 3 to 6, 2021. The team at Optometry Advisor will be reporting on a variety of the research presented by the primary eye care experts at the AAO. Check back for more from the AAO Optometry 2021 Meeting..

After bariatric surgery, patients with type 2 diabetes (T2D) were found to have reduced corneal sensitivity threshold. These findings were presented during Academy 2021 presented by the American Academy of Optometry held in Boston, Massachusetts November 3-6, 2021.

Patients with T2D have recently been found to have significantly altered tear film neuropeptides with lower levels of substance P (SP). In order to assess whether these features are improved following significant weight loss due to bariatric surgery, researchers from the University of Auckland in New Zealand recruited patients (N=29) with T2D who were about to undergo bariatric surgery. Patients were assessed for corneal sensitivity using noncontract aesthesiometry (NCCA) and tears were collected using the flush technique prior to surgery and at 12, 26, and 52 weeks after surgery.

The male:female ratio among the patient population was 11:18, patients had an average T2D duration of 11±7.6 years, and BMI prior to surgery was 44.7±6.4 kg/m2.

After surgery, glycated hemoglobin and BMI were significantly reduced (both P <.001).

NCCA decreased from 1.109 σ 0.795mBAR at baseline to 0.6218 σ 0.5370mBAR at 52 weeks (F[1.382,35.10], 4.513; P =.0295). Tear total protein and SP concentrations did not change significantly from baseline. Calcitonin gene related protein (CGRP) was significantly increased at week 26 (P <.001) and between weeks 12 and 26 (P =.021) but returned to baseline levels by week 52.

Neuropeptides were correlated with each other but not with other assessed ocular surface features. In addition, there was an inverse relationship observed between neuropeptides and BMI (β, −3.863±1.536; P =.014).

This study was limited by its short duration. It remains unclear whether long-term maintenance of weight loss following bariatric surgery alters ocular surface features.

The study authors concluded that improved glycemic control and weight loss due to bariatric surgery improved corneal sensitivity threshold but had little effect on neuropeptides among patients with T2D.

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Misra S, Dykgraaf J, Slater J, et al. Neuropeptides in the tear film of patients with diabetes and obesity, after bariatric surgery. Poster presented at the American Academy of Optometry; November 3-6; Boston. Board #37.