This original clinical study is the first to investigate the potential presence of Small Fibre Neuropathy (SFN) in patients with mesh continence devices. Mesh-Associated Pain Syndrome (MAPS) is characterised by neuropathic pain. Surgical excision of mesh is commonly pursued. Given the known association between neuropathic pain and small fibre nerve damage, this study explores the hypothesis that SFN may contribute to the symptom profile of MAPS. The aim is to evaluate the utility of Corneal Confocal Microscopy (CCM)—a novel, rapid, and non-invasive ophthalmic imaging technique—in objectively identifying and quantifying small nerve fibre loss in patients with MAPS related to a single continence device. The study also examines whether surgical removal of the mesh is associated with improvement in small fibre parameters suggestive of SFN recovery.

A prospective observational cohort study conducted within a quaternary-level mesh complication service. Seventy women were enrolled and divided into three age- and BMI-matched groups: 26 with MAPS, 22 pain-free patients with mesh devices, and 22 healthy mesh-free controls. All participants underwent assessment of small nerve fibre integrity using CCM, including nerve fibre density, branch density, and fibre length. Pain was evaluated using the Pain DETECT Questionnaire (PDQ), while quality of life and functional capacity were assessed with the EQ-5D. Mental well-being was measured using the WHO-5 wellbeing index. Four MAPS patients underwent repeat CCM a minimum of six months after mesh excision and paired pre- and post-operative data were analyzed.

The mean ages and body-mass index of subjects with MAPS, pain-free subjects with mesh and healthy controls did not differ ((58.96 ±7.28 vs 59.18 ±7.26 vs 54.45 ±8.05 years, p=0.07) (30.18 ±6.58 vs 29.34 ±4.61 vs 29.35 ±6.25, p=0.87). Patients with MAPS had a mean PDQ score of 20.77 ± 1.54 suggestive of a neuropathic mediated pain mechanism. 
This cohort had significantly reduced nerve fibre densities, nerve branch densities and nerve fibre length compared to pain-free subjects with mesh ( CNFD 15.85 ± 0.83 vs 27.46 ± 6.84 p= <0.0001), (CNBD 14.77 ± 1.31 vs 32.41 ± 14.53 p=<0.0001), ( CNFL 9.88 ± 0.49 vs 15.67 ± 3.41,  p= <0.0001) and healthy mesh-free controls (CNFD 15.85 ± 0.83 vs 29.43 ± 6.30, p=<0.0001), (CNBD 14.77 ± 1.31 vs 39.68 ± 18.92 p=<0.0001), (CNFL 9.88 ± 0.49 vs 17.21 ± 3.46, p=<0.0001). Functional capacity and mental and physical well-being were significantly reduced in patients with MAPS compared to pain-free subjects with mesh (p=<0.0001). Following surgical excision, CCM at six months showed a trend towards improvement in nerve fibre parameters; however, these changes were non- significant (p = 0.50, 0.15, 0.33), due to the small sample size.

CCM identified evidence of small fibre nerve damage in patients with MAPS, correlating with reduced quality of life and impaired physical, functional, and mental well-being. While surgical excision may offer some improvement in small nerve fibre integrity, no statistically significant change was observed in this study. However, the small sample size limits the ability to draw definitive conclusions regarding treatment effect.

These findings support a possible link between MAPS and Small Fibre Neuropathy (SFN). CCM may be a useful, non-invasive tool for detecting and monitoring small fibre loss in this patient group. Further large-scale studies are needed to better understand the therapeutic role of surgical excision and validate CCM as an objective measure of treatment response in clinical trials.