Longitudinal changes in retinal structure and visual function after mild methanol inhalation poisoning

Area of Science:

• Ophthalmology
• Neuroscience
• Toxicology

Background:

• Methanol poisoning is a serious condition that can lead to vision loss.
• Retinal structural and functional changes are key indicators of optic nerve damage in methanol poisoning.

Purpose of the Study:

• To characterize the retinal structural and functional changes in patients with mild methanol poisoning.
• To assess the long-term effects of methanol poisoning on visual acuity, visual fields, and retinal nerve fiber layer thickness.

Main Methods:

• 17 patients with methanol poisoning were divided into two groups based on initial visual acuity.
• Ophthalmic evaluations included best-corrected visual acuity (BCVA), visual field index (VFI), mean deviation (MD), and optical coherence tomography (OCT) to measure retinal thickness.
• Longitudinal follow-up occurred over 4 months to track changes in these parameters.

Main Results:

• Patients with initially worse vision (Group 1) showed significant visual recovery but persistent deficits compared to those with normal vision (Group 2).
• Both groups exhibited progressive thinning of the retinal nerve fiber layer (RNFL) and ganglion cell-inner plexiform layer (GCIPL), indicating ongoing structural damage.
• Group 1 experienced more severe structural deterioration, particularly in the GCIPL within the first two weeks.

Conclusions:

• Mild methanol poisoning can lead to progressive, long-term structural and functional retinal damage, even in individuals with initially normal vision.
• The dissociation between functional recovery and structural decline highlights the need for extended patient monitoring.
• Developing neuroprotective strategies is essential to mitigate the lasting effects of methanol toxicity on vision.