Variation of potential pain biomarkers in saliva of patients after Advanced Surface Ablation (ASA) refractive technique

Abstract

Purpose : Analysis biomarkers in saliva can be an objective method to quantify acute pain in a clinical model of post-surgical pain after corneal refractive surgery. Validation of this hypothesis in a clinical sample would validated this proposed clinical model as reliable, quantitative, and repetitive to test new pain management strategies and protocols

Methods : A multicenter, prospective, cohort study, based on 32 caucasian patients between 18 and 60 years-old, free from ocular pain of any origin, who were treated with alcohol-assisted surface ablation with epithelial removal (ASA) in both eyes were included.
Pain intensity was evaluated by Visual Analogue Scale (VAS) and Numeric Pain Rating Scale (NPRS) before and after surgery. Comorbidities (photophobia, burning, tearing, and foreign-body sensation), Hospital Anxiety/Depression (HAD) questionnaire, Quality of Life (QoL) questionnaire, and Visual Function 25 (VF25) questionnaire were gathered before and at 6h after surgery. Saliva was collected with the passive secretion method at basal day (V0), before the surgery (V1) and at 2 (V2) and 24 hours (V3) after surgery. Salivary cortisol, α-amylase (sAA), secretory IgA (sIgA), testosterone, and soluble fraction of receptor II of TNFα (sTNFαRII) concentrations were analyzed.
Baseline characteristics were summarized with standard descriptive statistics, and descriptive analyses were carried out. Analysis of variance (ANOVA) with repeated measures was used to evaluate mean differences over time. Functional Data Analysis (FDA) was used for analyzing the temporal evolution of VAS scores. P values <0.05 were considered statistically significant

Results : Level of sIgA in V2 was significantly higher than in V1 (p 0.0012) and V3 (p 0.0013). Level of sTNFαRII in V2 was significantly higher than in V1 (p 0.0001) and V3 (p 0.0049). Level of cortisol in V0 was significantly lower than in V1 (p<0.0001) and V2 (p 0.0071). Level of sAA in V0 was significantly lower than in V2 (p<0.0001) and V2 (p 0.0071). In the remaining biomarkers no statistically significant variations were found

Conclusions : Salivary sIgA and sTNFαRII show an increase related to pain intensity. Thus ASA could be a useful novel human model of acute post-operative pain for testing new analgesic protocols

This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.

 

Evolution of sIgA concentration

 

Evolution of sTNFαRII concentration