Low-level laser therapy for carpal tunnel syndrome

Area of Science:

• Orthopedics
• Physical Medicine & Rehabilitation
• Pain Management

Background:

• The efficacy of low-level laser therapy (LLLT) for carpal tunnel syndrome (CTS) remains debated.
• Some studies indicate LLLT benefits, while others show no significant advantage over placebo or alternative treatments.

Purpose of the Study:

• To evaluate the benefits and harms of LLLT compared to placebo and other non-surgical interventions for CTS.
• To synthesize evidence from randomized controlled trials (RCTs) on LLLT for CTS.

Main Methods:

• Systematic review of RCTs identified through comprehensive database searches (CENTRAL, MEDLINE, Embase, Science Citation Index Expanded).
• Inclusion criteria: RCTs comparing LLLT with placebo or non-surgical treatments for CTS, regardless of publication status or language.
• Data extraction and analysis using random-effects models for continuous outcomes (MD, SMD) and risk ratios for dichotomous data.

Main Results:

• 22 RCTs with 1153 participants were included, comparing LLLT with placebo, ultrasound, steroid injections, and other non-surgical options.
• Evidence quality was predominantly very low to low, with most studies being small and having a high risk of bias.
• Short-term follow-up showed very low-quality evidence for LLLT's effect on symptom severity and functional status compared to placebo. Uncertain effects on visual analogue scale (VAS) pain and nerve conduction.
• LLLT may slightly improve grip and finger-pinch strength versus placebo (low-quality evidence), with only VAS pain and finger-pinch strength potentially meeting minimal clinically important differences (MCIDs).
• LLLT appears less effective than ultrasound for short-term pain and strength improvements (very low to low-quality evidence).
• Insufficient evidence exists for long-term effects, comparisons with other non-surgical treatments, and adverse events.

Conclusions:

• Current evidence quality for LLLT in CTS is very low, with no robust data supporting clinical efficacy.
• Observed improvements in VAS pain and finger-pinch strength may be overestimated due to study limitations.
• LLLT may be less effective than ultrasound for short-term symptom relief in CTS.
• Further high-quality, definitive, and blinded research is necessary to ascertain LLLT's role in CTS management.