ESCRS - POANT034 - Anterior Chamber Configuration And Intraocular Pressure Changes Assessed By Ultrasound Biomicroscopy During Hyperbaric Oxygen Therapy

Anterior Chamber Configuration And Intraocular Pressure Changes Assessed By Ultrasound Biomicroscopy During Hyperbaric Oxygen Therapy

Published 2026 - 44th Congress of the ESCRS

Reference: POANT034 | Type: Poster | DOI: 10.82333/bnma-ej79

Authors: A/Prof. Asma Khallouli* 1 , Dr Rahma Saidane 1 , Dr Racem Choura 1 , Dr Raja Ben Sassi 2 , Dr Zeineb Kallel 1 , A/Prof. Hedi Gharsallah 2 , A/Prof. Afef Maalej 1

1Ophthalmology,Military Hospital,Tunis,Tunisia, 2Hyperbaric Oxygen Therapy Unit,Military Hospital,Tunis,Tunisia

Purpose

To investigate anterior chamber configuration using ultrasound biomicroscopy (UBM) and its relationship with intraocular pressure (IOP) variations during hyperbaric oxygen therapy (HBOT).

Setting

Ophthalmology Department and Hyperbaric Medicine Unit, Military Hospital of Tunis, Tunisia.

Methods

Seventy-four patients (148 eyes) without ocular pathology underwent standardized UBM imaging during HBOT (2.5 ATA, ≥30 sessions). Parameters analyzed included lens vault, angle opening distance at 500 μm (AOD500), angle recess area (ARA500/750), and trabecular-iris space area (TISA750). IOP was measured at each visit. Assessments were performed at baseline and every 10 sessions up to 60 sessions, with a 3-month post-treatment control.

Results

UBM showed stable anterior chamber configuration throughout follow-up, with no significant changes in lens vault or angle parameters (AOD500, ARA500/750, TISA750) at any time point (all p>0.05). Conversely, IOP demonstrated a progressive and significant decrease starting from session 20 (p<0.05), reaching a maximum reduction at S60 (mean decrease ≈3 mmHg). At 3-month follow-up, IOP returned to baseline levels (p=NS), confirming the reversibility of this effect. No structural anterior segment crowding or anterior lens displacement was observed.

Conclusions

UBM imaging confirms the structural stability of the anterior chamber and lens position during HBOT, despite a transient and reversible reduction in IOP. These findings suggest that HBOT-related IOP decrease is likely functional rather than due to anatomical modifications detectable by UBM.