Oriani2
When performing visual evoked potential studies on the macula, rate of recovery of P100 amplitude after dazzling may be altered following repeated hyperbaric exposures.
Clinical Bottom Line: 1. Vague findings of unknown significance. Appraised by: Mike Bennett, Dept. of Diving and Hyperbaric Medicine, Prince of Wales Hospital Sydney; Saturday, 21 August 1999
Clinical Scenario: A patient receiving hyperbaric oxygen for retinal ischaemic pathology. Three-part Question: For patients having hyperbaric oxygen therapy for retinal ischaemic pathology, does rate of recovery of a visual evoked potential (VEP) after dazzling usefully indicate any benefit of hyperbaric therapy? Search Terms: Visual evoked potential, retinal ischaemia
The Study: Double-blinded randomised controlled trial intention-to-treat probable. Volunteers, men and women. Control group (N = 8; 8 analysed): One session breathing air at 2.5ATA for 90 minutes. Experimental group (N = 7; 7 analysed): One session breathing 100% oxygen at 2.5ATA for 90 minutes
The Evidence:
Non-Event Outcomes Time to outcome Control group HBO group P-value P100 latency and amplitude before and after unchanged unchanged Not given
Amplitude recovery after ?unchanged ?unchanged Not Sig
Comments: 1. No quantitative results given. 2. Some subjects had multiple exposures, it is not known how many. It appears from the text it is these patients that may have shown a difference in rate of recovery of P100 amplitude. 3. Methodology and results not presented clearly. 4. Authors conclusions do not seem to clearly follow from results.
Expiry date: April 2021 References: 1. Oriani G, Magni R, Musini A, Meazza D, Brancato R. A new electrophysiological test to assess ophthalmological benefits of hyperbaric therapy. Proceedings of the 10th International Congress on Hyperbaric Medicine, Amsterdam. Best Publishing, Flagstaff, Arizona 1992:104-109.
