Effect of SCUBA Diving on Ophthalmic Parameters

Abstract

Background and Objective: Several cases of central serous chorioretinopathy (CSC) in divers have been reported in our medical retina center over the past few years. This study was designed to evaluate possible changes induced by SCUBA diving in ophthalmic parameters and especially subfoveal choroidal thickness (SFCT), since the choroid seems to play a crucial role in physiopathology of CSC. Materials and Methods: Intraocular pressure (IOP), SFCT, pachymetry, flow-mediated dilation (FMD), blood pressure, and heart rate were measured in 15 healthy volunteer divers before diving, 30 and 60 min after a standard deep dive of 25 m depth for 25 min in a dedicated diving pool (NEMO 33). Results: SFCT reduces significantly to 96.63 ± 13.89% of pre-dive values (p = 0.016) 30 min after diving. It recovers after 60 min reaching control values. IOP decreases to 88.05 ± 10.04% of pre-dive value at 30 min, then increases to 91.42 ± 10.35% of its pre-dive value (both p < 0.0001). Pachymetry shows a slight variation, but is significantly increased to 101.63 ± 1.01% (p = 0.0159) of the pre-dive value, and returns to control level after 60 min. FMD pre-dive was 107 ± 6.7% (p < 0.0001), but post-dive showed a diminished increase to 103 ± 6.5% (p = 0.0132). The pre-post difference was significant (p = 0.03). Conclusion: Endothelial dysfunction leading to arterial stiffness after diving may explain the reduced SFCT observed, but SCUBA diving seems to have miscellaneous consequences on eye parameters. Despite this clear influence on SFCT, no clear relationship between CSC and SCUBA diving can be drawn.

Keywords: arterial stiffness; central corneal thickness; central serous chorioretinopathy; endothelial dysfunction; flow-mediated dilation; intraocular pressure; subfoveal choroidal thickness.

Figure 1

Bar graph illustrating the reduction of FMD 30 min post dive (black bar) compared to predive values (Blue Bar) (mean ± SD). (N = 15).

Figure 2

Number of bubbles (BBS = Bubbles) per heartbeat 30 min (blue bar) and 60 min (black bar) after diving. (Mean ± SD).

Figure 3

Enhanced depth imaging-optical coherence tomography (EDI-OCT) showing different structures. From anterior to posterior: Vitreous body (green), neurosensory retina and the retinal pigment epithelium (red), choroid (SFCT in blue), and sclera (yellow).

Figure 4

Comparison of SFCT in the same diver before the dive ((A), SFCT estimated at 243 µm by one of the investigators), and 30 min after the dive ((B), SFCT estimated at 232 µm).