CRAO is a sudden, painless loss of vision. It is the most recently approved indication from the UHMS for HBOT. CRAO is caused by the obstruction of the retinal artery and can lead to permanent vision loss, although this is very rare.
Most treatments for CRAO don’t work. HBOT is useful in preserving vision if started within 8 hours of the first vision loss. Patients in a small study who had HBOT had 82% vision improvement versus the control group with only 29.7% improvement. Treatment is administered at 2 ATA on 100% O2. If no improvement or response, pressure is increased to 2.8 ATA for 90 minutes for three days.47