Condition focus: Optic Nerve Injury & Neuroprotection

Traumatic optic nerve injury leads to rapid retinal ganglion cell death and irreversible vision loss with limited therapeutic interventions available. This study investigated whether 670 nm near-infrared light could provide neuroprotection following acute optic nerve injury. Rats underwent optic nerve crush injury with experimental groups receiving 670 nm LED treatment at various time points relative to injury, while outcomes included retinal ganglion cell survival, axonal integrity, and visual function assessed through histology and electrophysiology.

Animals treated with 670 nm light demonstrated significantly improved retinal ganglion cell survival compared to untreated controls, with up to 40% more RGCs preserved in treated groups. Axonal integrity within the optic nerve was better maintained, and visual evoked potential responses were superior in treated animals. The neuroprotective effects were most pronounced when treatment was initiated shortly after injury, though benefits were observed even with delayed treatment initiation. Mechanistic analysis revealed enhanced mitochondrial function, reduced oxidative stress, and decreased inflammatory markers in treated optic nerves. These findings establish 670 nm photobiomodulation as a potent neuroprotective strategy for acute optic nerve trauma, with potential clinical applications for traumatic optic neuropathy.

WaveFront Alignment:
Szymanski’s demonstration of robust RGC neuroprotection with 670 nm treatment following optic nerve injury validates the Spectral WaveFront’s wavelength selection for optic nerve conditions, supporting applications in traumatic and degenerative optic neuropathies.

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Editor’s note: Szymanski 2013 demonstrates 670 nm neuroprotection in optic nerve crush injury. For related optic nerve applications, see Fitzgerald 2010 and Rojas 2008. Wavelength comparison appears in Giacci 2014. Broader mitochondrial neuroprotection context in Beirne 2017. Secondary degeneration mechanisms relevant to optic nerve injury appear in Fitzgerald 2010.

Related Articles

• NIR Reduces Oxidative Stress in Optic Nerve Injury – Fitzgerald 2010
• Neuroprotective Effects of NIR in Mitochondrial Optic Neuropathy – Rojas 2008
• 670nm vs 830nm: Comparative Neuroprotection – Giacci 2014
• Photostimulation of Mitochondria for Retinal Neurodegeneration – Beirne 2017
• 670 nm Light Reduces Complement Propagation – Rutar 2012

Key Takeaways

• 670 nm treatment preserved up to 40% more retinal ganglion cells following optic nerve crush injury
• Better maintained axonal integrity and superior visual evoked potential responses versus controls
• Most pronounced neuroprotection with early treatment initiation, though delayed treatment still beneficial
• Enhanced mitochondrial function and reduced oxidative stress/inflammation in treated optic nerves

Study Overview

Full Citation

Szymanski CR, et al. (2013). Photobiomodulation with near infrared light increases retinal ganglion cell survival following axotomy. Clin Exp Ophthalmol, 41(9):857-865. View Publication