Experimental Study on Ocular Surface Protection by Soft Contact Lenses Due to Volcanic Ash Exposure

Area of Science:

• Ophthalmology
• Environmental Health
• Disaster Medicine

Background:

• Sudden volcanic eruptions can cause eye exposure to ash, leading to discomfort and complicating evacuations.
• The impact of volcanic ash on ocular tissues, particularly with soft contact lens (SCL) wear, is not well-documented.
• This study experimentally investigates the effects of volcanic ash on the eyes of SCL wearers versus bare eyes.

Purpose of the Study:

• To compare the ocular tissue damage caused by volcanic ash exposure in rabbits wearing SCLs versus those with bare eyes.
• To evaluate the protective effect, if any, of SCLs against volcanic ash-induced ocular injury.
• To inform public health guidelines regarding SCL wear during volcanic ashfall events.

Main Methods:

• White rabbits were divided into three groups: bare eye exposure, SCL-wearing eye exposure, and a control (eye washing only).
• Volcanic ash was applied to the eyes of the experimental groups under topical anesthesia, followed by immediate saline rinsing.
• Ocular examinations included slit-lamp microscopy and histopathological analysis post-euthanasia.

Main Results:

• The bare eye group exhibited significantly more severe corneal and conjunctival erosion compared to the SCL group.
• Eyes wearing SCLs showed limited ocular damage from volcanic ash exposure.
• The control group, receiving only eye washing, demonstrated no ocular damage.

Conclusions:

• Current guidelines recommend SCL removal during ashfall, but findings suggest SCLs may offer some protection against ash-related corneal and conjunctival damage.
• Ocular tissue damage was less severe in SCL-wearing eyes than in bare eyes following volcanic ash exposure.
• In sudden ashfall events, prioritizing evacuation over immediate SCL removal may be advisable for affected individuals.