The effects of hyperbaric oxygen therapy on retinal layers in healthy eyes

Purpose: The aim of our study is to investigate the effects of hyperbaric oxygen (HBO2) therapy on retinal layers in healthy eyes. Method: Thirty patients who were taken to outpatient HBO2 for any indication were included in the study. All patients underwent 10 sessions of HBO2; 20 healthy patients were taken as the control group. We used the spectral-domain optical coherence tomography (SD-OCT) to obtain automated measurements of thickness for each retinal layer – i.e., the retinal nerve fiber layer (RNFL), ganglion cell layer (GCL), inner plexiform layer (IPL), inner nuclear layer (INL), outer plexiform layer (OPL), outer nuclear layer (ONL) and retinal pigment epithelium (RPE) – and to conduct foveal (central 1 mm), inner-ring (parafoveal 1 to 3mm), and outer-ring (perifoveal 3 to 6mm) retinal layer measurements. Retinal OCT scans were performed before HBO2, after the first and 10th sessions. All retinal layer thicknesses were assessed with SD-OCT software system and compared between each visit. Retinal thicknesses were calculated in the central, inner ring and outer ring subfields (nine quadrants). Results: In SD-OCT measurements, there were no statistically significant difference before HBO2, after the first and 10th sessions in terms of foveal, inner-ring and outer-ring thickness of RNFL, GCL, IPL, INL, OPL, ONL and RPE. Conclusions: Our study demonstrated that there was no change in the thickness of the retinal layers after the first and 10th sessions in healthy eyes.