Alkali burns keep damaging the eye
Chemical splashes to the eye are emergencies, and alkali injuries are the most dangerous. Alkalis react with the fats in cell membranes, a process called saponification, which breaks down tissue and lets the chemical penetrate deeper into the cornea and the inner eye. An alkali keeps causing damage until it is washed out, so irrigation continues until the pH returns to normal, not until a fixed time has passed. Acids, by contrast, coagulate surface proteins, which forms a barrier and limits penetration.
Reading the pH result
The nurse started irrigation at once with normal saline, which is correct. After 15 minutes of continuous irrigation, the tear pH is 8.5. The clinic's target is 7.0–7.5. A pH of 8.5 means alkali remains in the eye. Fifteen minutes is the minimum duration, and alkali injuries often need much longer. The correct action is to continue irrigating and recheck the pH, usually a few minutes after stopping so the reading reflects the eye and not the irrigating fluid, and to repeat until the target is reached. Upper and lower lid fornices are irrigated well, since particles can lodge there.
| Finding | Meaning | Action |
|---|
| pH 8.5 after 15 minutes | Alkali remains | Continue irrigation |
| pH 7.0–7.5 | Target reached | Stop, then assess acuity and refer |
| Pain eased | Not proof of neutralization | Do not stop based on pain |
Why the other actions are wrong
Stopping because 15 minutes are complete treats the minimum time as the endpoint and leaves alkali in the eye. Measuring visual acuity and arranging referral are needed, but while the eye is still alkaline, every minute away from irrigation lets damage continue; acuity is checked after the pH is normal. Patching and referral do not remove the remaining alkali. Easing pain is also misleading, because alkali can damage nerve endings and reduce pain while injury continues.
After neutralization
When the pH is in range, the nurse checks visual acuity, documents the chemical, the duration of irrigation, and the pH values, and arranges urgent ophthalmology referral. Preventive teaching for the factory includes eye protection when handling cleaning solutions and eyewash stations near work areas.
Exam takeaway
Key point Chemical eye injury: irrigate immediately and keep irrigating until the pH is normal, especially for alkali. Time and pain relief are not the endpoints.