Description

Evanger K, Vaagbø G, Haugen OH, Müller B. Myopic Shift in Patients During Hyperbaric Oxygen

Treatment: A Systematic Review. Undersea Hyperb Med. 2026 Third Quarter; 53(3):481-494.

Introduction: Reversible myopic shift (MS) is a common side effect of hyperbaric oxygen treatment

(HBO2) resulting from refractive changes in the lens. Single studies indicate that the myopic shift

increases with longer duration of HBO2 and may differ between hyperbaric chamber types and oxygen

breathing systems. This review aims to improve knowledge on the frequency and magnitude of myopic

shift after standard-length HBO2.

Methods: A systematic search for original studies of myopic shift after HBO2 was conducted in medical

databases. Included were published full-text articles in English with specified details on oxygen

administration, pressure, number of treatments, and use of conventional techniques to measure

refraction. Studies with exposure other than HBO2, patients with artificial lenses, and single-case reports

were excluded.

Results: Of 153 reports identified, eight studies with 263 patients were included. Treatment durations

covered 18-21, 30, and 40 treatments in either monoplace or multiplace chambers using hoods or masks.

For the mean values of myopic shift and the incidence of a myopic shift ≥ 0.5 D, a range was seen from

the lowest values after 20 treatments in multiplace chambers using a mask (0.4 D and 53%, respectively),

to the highest values after 40 treatments using hoods (1.6 D and 100%, respectively). For monoplace

treatment, the corresponding numbers were 0.6 D and 70% after 18 treatments, and 0.95 D and 91% after

30 treatments.

Discussion: This review indicates that both the magnitude and incidence of myopic shift increase with

the number of HBO2 sessions and in the order multiplace-mask < monoplace < multiplace-hood.

Keywords: vision, ocular refraction, side effects