Theoretical Assessment of the Risk of Ocular Hypotony in Patients With Intravitreal Gas Bubbles Who Travel Through Subsea Tunnels

PURPOSE: This study was conducted to investigate changes in intraocular pressure (IOP) in the presence of intravitreal gas bubbles in individuals who travel through subsea tunnels. METHODS: Using a mathematical model, we simulated alterations in ocular globe shape, aqueous humor flow, volume of intravitreal gas bubbles, and IOP due to elevation changes during travel through subsea tunnels. We simulated five tunnels with different features as case studies. The role of key modeling parameters was further evaluated in a parametric study. RESULTS: In three out of the five simulated tunnels (i.e., Seikan Tunnel, Bomlafjord Tunnel, and the Atlantic Ocean Tunnel), the patients were potentially at risk at lower portions of the tunnels since the IOP dropped to values less than 5 mm Hg, the clinical threshold for ocular hypotony. During ascent, the IOP increased to the normal value of 15 mm Hg and in some cases to higher values (e.g., a peak value of 22 mm Hg in Seikan Tunnel). CONCLUSIONS: Our model predicted that in the presence of intravitreal gas bubbles, the IOP could drop to extremely low values when patients descend to lower elevations in some tunnels. Such low IOP values could cause bleeding and/or retinal detachment. Since many factors (e.g., tunnel specifications and/or patient-specific characteristics) could affect the IOP during subsea travel, caution (beyond avoiding airplane flights) should be taken in advising patients about travel restrictions following intravitreal gas injections. TRANSLATIONAL RELEVANCE: Our findings highlight the potential risk for hypotony in the presence of intravitreal gas bubbles during subsea travels.