Symptoms
Snow blindness occurs with a delay within approximately 3-12 hours after exposure to UV radiation, often in the afternoon, evening, or night. It manifests itself in the following symptoms:
- Unbearable pain in both eyes
- Foreign body sensation, “sand in the eyes”
- Trickling of tears
- Conjunctivitis and redness, conjunctival swelling.
- Corneal inflammation
- Eyelid spasm, i.e. compulsive closing of the eyes due to increased sensitivity to light.
- Mild visual disturbances may occur and a simultaneous sunburn of the skin is sometimes observed.
Thus, the term snow “blindness” does not refer to true blindness or retinal damage, but refers to the eyelids temporarily unable to open.
Causes
The disease is caused by UV-B radiation, which leads to sunburn of the cornea and conjunctiva (photoconjunctivitis and -keratitis) with painful, small epithelial lesions, loosening of the epithelium of the cornea, and death of epithelial cells. Exposed nerve endings are responsible for the extreme pain. Possible triggers include spending time in the snow or at the beach without sunglasses and welding without goggles. Snow, sand and water reflect UV radiation, leading to additional indirect irradiation.
Complications
In severe cases, desquamation of the epithelium with delayed healing is possible. Superinfection, blindness, and other ocular complications may also occur.
Diagnosis
Diagnosis is made by medical treatment based on patient history and eye examination. Similar complaints are caused, for example, by an acute glaucoma attack or foreign bodies in the eye. Other possible eye diseases must be excluded in medical treatment.
Prevention
Wear good sunglasses or safety glasses! Do not watch while welding and also do not look into reflective surfaces. Repeated damage should be avoided.
Treatment
Treatment is preferably under ophthalmologic care. The focus is on pain management, avoidance of further UV exposure, and prevention of superinfection. The indications are inconsistent. The following medicinal measures are mentioned in the literature:
- Single-dose local anesthetic eye drops, e.g., oxybuprocaine eye drops to relieve pain at diagnosis and to sedate the patient. Local anesthetics should not be given to patients – despite the good effectiveness – because repeated use quickly leads to damage to the corneal epithelium (!) Even a single application causes small epithelial lesions.
- Disinfecting eye ointment or antibiotic eye ointment to prevent superinfection and protect the cornea.
- Evt. Dexpanthenol eye ointment to promote regeneration.
- Anti-inflammatory and analgesic NSAID eye drops, such as diclofenac eye drops or indometacin.
- Analgesics for pain relief, e.g., oral ibuprofen or acetaminophen.
Cool compresses can also help relieve pain. Further exposure to light should be avoided. For this purpose, a bilateral eye bandage is applied. Bed rest in a darkened room or wearing good sunglasses is also recommended. Contact lenses must be removed and the eyes should not be rubbed. Because of the good regeneration of the cornea, snow blindness usually heals quickly within about 24-48 hours.
