Biometric Changes Associated With Hyperbaric Oxygen Therapy

The purpose of this study was to describe biometric changes over the course of hyperbaric oxygen therapy (HBOT) treatment and suggest caution in the timing of cataract surgery in patients undergoing HBOT.   

Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota, USA

We describe changes in biometry in an index patient undergoing HBOT for a systemic issue prior to cataract surgery. The patient underwent serial biometries and the following parameters were assessed for changes during HBOT: axial length, anterior chamber depth, lens thickness, and effective lens position. The impact on intraocular lens (IOL) selection was estimated.

Initial biometry after 5 sessions of HBOT showed right and left axial lengths (AL) of 24.06mm and 23.93mm, respectively. Anterior chamber depth (ACD) was 3.82mm and 3.80mm. Lens thickness (LT) was 3.26mm in both eyes. Effective lens position (ELP) 5.13mm and 5.11mm. Biometry done at after 37 sessions of HBOT showed right and left AL of 24.07mm and 23.92mm, respectively. ACD was 3.78mm and 3.75mm. LT was 3.28mm and 3.29mm. ELP was 5.11mm and 5.09mm. Biometry done 4 days after completion of therapy showed right and left AL of 24.05mm and 23.92mm, respectively. ACD was 3.77mm and 3.75mm. LT was 3.28mm and 3.23mm. ELP was 5.10mm and 5.06mm.

Patients undergoing systemic HBOT are at risk of biometric changes. In this patient, ACD and ELP decreased in both eyes, and LT increased in the right and fluctuated in the left. Using the Barrett formula aiming for a plano target, the IOL that would have been selected for implantation varied by 0.5 diopters in both eyes. Serial biometric testing can assist with pre-operative planning to optimize IOL selection in this patient population. Further studies are needed to assess these changes over time in a large cohort and to better establish the mechanism of these changes.