Vingolo
Patients with retinitis pigmentosa who received hyperbaric oxygen did not show deterioration in electroretinographic response (ERG), and a small proportion improved.
Clinical Bottom Line: 1. HBO administration prevented deterioration in electroretinographic responses over 3 years. 2. HBO administration increased mean electroretinographic responses over the 3 years of the study, but only a small proportion of subjects improved. Citation: 1. Vingolo E, Pelaia, Forte R. Rocco M, Giusti C, Rispole E. Does hyperbaric oxygen (HBO) delivery rescue retinal photoreceptors in retinitis pigmentosa? Documenta Opthalmologica 97: 33-39, 1999
Three-part Clinical Question: For patients with retinitis pigmentosa, does hyperbaric oxygen therapy (when compared to no treatment) modify electroretinographic responses? Search Terms: hyperbaric oxygenation, retinitis pigmentosa
The Study: Non-blinded randomised controlled trial with intention-to-treat. The Study Patients: A diagnosis of retinitis pigmentosa with clearly identified inheritance. Specific criteria and electroretinographic (ERG) data were utilised to aid diagnosis. Control group (N = 24; 24 analysed): No specific treatment. Experimental group (N = 24; 24 analysed): Hyperbaric oxygen therapy (Schedule: 100% O2 at 2.2 ATA for 90 mins). 1st month: 5 treatments per week. Next 11 months: one week of treatments per month. Year 2 and 3: one week of treatments every 3 months.
The Evidence:
| Outcome | Time to Outcome | Control group | Hyperbaric group | Relative risk reduction | ARR | NNT |
| ERG improved | 3 years | 0 | .11 | INF | -0.11 | 9 |
| 95% CI: | -0.24 to 0.02 | NNT 4 to INF NNH = 66 to INF | ||||
| ERG deteriorated | 3 years | 0.62 | 0 | 100% | 0.62 | 2 |
| 95% CI: | 0.43 to 0.81 | 1 to 2 |
| Measure | Control Group Mean | SD | HBO Group Mean | SD | Difference | 95% CI |
| ERG b-wave amplitude in microV at 1 year | 5.04 | 3.07 | 8.46 | 5.71 | 3.42 | 0.76 to 6.09 |
| ERG b-wave amplitude in microV at 2 years | 3.46 | 2.77 | 10.7 | 7.6 | 7.24 | 3.92 to 10.57 |
| ERG b-wave microV at 3 years | 2.97 | 3.61 | 14.4 | 11.7 | 11.43 | 16.46 to-6.40 |
Comments: 1. Small study with highly defined patient population. Severely affected individuals were excluded. 2. This study suggests that treatment with HBO will prevent ERG deterioration in 1 out every 2 patients over 3 years. 3. Visual acuity was not estimated in this study and ERG response may not equate with important changes in visual acuity.
Appraised by: Juliette Leverment and Mike Bennett Prince of Wales Hospital, Sydney; Friday, 6 December 2002 Email: [| jullietteleverment@hotmail.com] Kill or Update By: March 2014
