Emergency treatment of eye burns: which rinsing solution should we choose?
BACKGROUND: In the treatment of eye burns few data on the comparative application of rinsing solutions exist. We present experiments in vitro and ex vivo on the pH changes that can be achieved in alkali eye burns with currently distributed and propagated rinsing fluids like water, saline solution, Cederroth Eye Wash Solution (including borate buffer), Diphoterine, Ringers lactate solution and phosphate buffer. METHODS: Titration curves in beakers are compared with ex vivo experiments on isolated rabbit eyes. We exposed eyes to burns from filter paper soaked in 2 mol NaOH, continuously measuring the anterior chamber pH by means of a micro pH electrode placed near the endothelium. In each experiment--repeated five times--the corneal burn of 20 s in 2 mol NaOH was followed by a period of 15 min of rinsing under a defined flow of 66 ml/min. RESULTS: We found highly significant differences in intracameral pH related to different types of rinsing solutions. The return of the intracameral pH to normal was not achieved by any of the rinsing fluids, but the best results were noted for of Cederroth Eye Wash Solution (Cederroth Industrial Products, Upplands Väasby, Sweden) and the Diphoterine- and Previn solutions (Prevor, Cologne, Germany). Water played an intermediate role whereas saline and phosphate buffer were not efficient at lowering intracameral pH after alkali burns. CONCLUSION: In alkali burns we recommend efficient buffering solutions. The tested isotonic phosphate buffer (PBS) was not effective at buffering the intraocular pH. Water was found to be much less efficient than Previn, Diphoterine or Cederroth Eye Wash solution in balancing intraocular pH.