Er:YAG Laser Therapy for Diabetic Foot Ulcers: A Pilot Study with Hyperspectral Imaging Assessment
Journal: The International Journal of Lower Extremity Wounds (2026)
Authors: Sebastián Flores-Escobar, Francisco Javier Álvaro-Afonso, Yolanda García-Álvarez, Mateo López-Moral, Irene Sanz-Corbalán, José Luis Lázaro-Martínez
Institution: Diabetic Foot Unit, Complutense University of Madrid & Hospital Clínico San Carlos, Madrid, Spain
Abstract
This prospective pilot study investigated the feasibility and physiological effects of adjunctive Er:YAG laser therapy for diabetic foot ulcers using Hyperspectral Imaging (HSI)—a non-invasive imaging technology capable of objectively measuring tissue perfusion and oxygenation.
Five patients with diabetic foot ulcers received weekly Er:YAG laser treatment in addition to standard wound care over an 8-week period. Clinical outcomes included wound area reduction and wound-bed quality, while physiological changes were assessed using hyperspectral imaging parameters, including tissue oxygen saturation (StO₂), oxyhemoglobin (OxyHb), deoxyhemoglobin (DeoxyHb), and total hemoglobin (THb).
Study Design
Key Clinical Findings
Clinical improvement was observed throughout the treatment period:
Although complete healing was not expected within the relatively short 8-week follow-up and the pilot sample was small, the observed clinical improvements were considered clinically meaningful.
Objective Evidence of Improved Microcirculation
Unlike previous studies relying primarily on wound size measurements, this investigation objectively evaluated tissue physiology using Hyperspectral Imaging (HSI).
The study demonstrated statistically significant increases in:
Importantly, these physiological improvements became evident during treatment and were accompanied by visible improvements in wound-bed quality. The representative HSI images clearly illustrate increased perfusion around the ulcer after treatment, providing objective evidence of enhanced microvascular activity.
Why This Study Matters
This publication is the first clinical study to combine Er:YAG laser therapy with Hyperspectral Imaging for the assessment of diabetic foot ulcers.
Rather than relying solely on wound closure, the investigators demonstrated measurable physiological improvements in tissue perfusion and oxygen delivery—key biological processes required for successful wound healing.
The use of HSI provides clinicians with an objective method for monitoring tissue response and may enable earlier assessment of treatment effectiveness before visible clinical changes occur.
Authors' Conclusions
The authors conclude that adjunctive Er:YAG laser therapy was associated with:
while Hyperspectral Imaging proved to be a promising tool for objective monitoring of wound healing physiology.
The authors recommend larger controlled clinical trials to further validate these findings.
Citation
Flores-Escobar S, Álvaro-Afonso FJ, García-Álvarez Y, López-Moral M, Sanz-Corbalán I, Lázaro-Martínez JL.
Er:YAG Laser Therapy for Diabetic Foot Ulcers: A Pilot Study with Hyperspectral Imaging Assessment.
The International Journal of Lower Extremity Wounds. 2026.
DOI: 10.1177/15347346261459556
Journal: The International Journal of Lower Extremity Wounds (2026)
Authors: Sebastián Flores-Escobar, Francisco Javier Álvaro-Afonso, Yolanda García-Álvarez, Mateo López-Moral, Irene Sanz-Corbalán, José Luis Lázaro-Martínez
Institution: Diabetic Foot Unit, Complutense University of Madrid & Hospital Clínico San Carlos, Madrid, Spain
Abstract
This prospective pilot study investigated the feasibility and physiological effects of adjunctive Er:YAG laser therapy for diabetic foot ulcers using Hyperspectral Imaging (HSI)—a non-invasive imaging technology capable of objectively measuring tissue perfusion and oxygenation.
Five patients with diabetic foot ulcers received weekly Er:YAG laser treatment in addition to standard wound care over an 8-week period. Clinical outcomes included wound area reduction and wound-bed quality, while physiological changes were assessed using hyperspectral imaging parameters, including tissue oxygen saturation (StO₂), oxyhemoglobin (OxyHb), deoxyhemoglobin (DeoxyHb), and total hemoglobin (THb).
Study Design
- Study type: Prospective pilot study
- Study center: Complutense University of Madrid
- Patients: 5 diabetic foot ulcer patients
- Treatment duration: 8 weeks
- Treatment frequency: Weekly Er:YAG laser sessions
- Adjunctive therapy: Standard of Care according to IWGDF guidelines
- Novel assessment method: Hyperspectral Imaging (HSI) using SnapshotNIR technology
Key Clinical Findings
Clinical improvement was observed throughout the treatment period:
- Mean wound area reduction of 33.1% after 8 weeks
- Significant improvement in wound-bed quality measured using the Wollina Wound Score
- Progressive formation of healthy granulation tissue
- Good feasibility and safety throughout the study
Although complete healing was not expected within the relatively short 8-week follow-up and the pilot sample was small, the observed clinical improvements were considered clinically meaningful.
Objective Evidence of Improved Microcirculation
Unlike previous studies relying primarily on wound size measurements, this investigation objectively evaluated tissue physiology using Hyperspectral Imaging (HSI).
The study demonstrated statistically significant increases in:
- Total Hemoglobin (THb) – indicating increased local blood volume and capillary perfusion
- Oxyhemoglobin (OxyHb) – indicating improved oxygen delivery to the tissue
Importantly, these physiological improvements became evident during treatment and were accompanied by visible improvements in wound-bed quality. The representative HSI images clearly illustrate increased perfusion around the ulcer after treatment, providing objective evidence of enhanced microvascular activity.
Why This Study Matters
This publication is the first clinical study to combine Er:YAG laser therapy with Hyperspectral Imaging for the assessment of diabetic foot ulcers.
Rather than relying solely on wound closure, the investigators demonstrated measurable physiological improvements in tissue perfusion and oxygen delivery—key biological processes required for successful wound healing.
The use of HSI provides clinicians with an objective method for monitoring tissue response and may enable earlier assessment of treatment effectiveness before visible clinical changes occur.
Authors' Conclusions
The authors conclude that adjunctive Er:YAG laser therapy was associated with:
- improved wound-bed quality,
- clinically meaningful wound size reduction,
- increased tissue perfusion,
- improved oxygen delivery,
while Hyperspectral Imaging proved to be a promising tool for objective monitoring of wound healing physiology.
The authors recommend larger controlled clinical trials to further validate these findings.
Citation
Flores-Escobar S, Álvaro-Afonso FJ, García-Álvarez Y, López-Moral M, Sanz-Corbalán I, Lázaro-Martínez JL.
Er:YAG Laser Therapy for Diabetic Foot Ulcers: A Pilot Study with Hyperspectral Imaging Assessment.
The International Journal of Lower Extremity Wounds. 2026.
DOI: 10.1177/15347346261459556