Intraocular pressure elevation and choroidal thinning

Area of Science:

• Ophthalmology
• Optometry
• Medical Imaging

Background:

• Intraocular pressure (IOP) is a critical factor in ocular health, influencing conditions like glaucoma.
• Choroidal thickness, particularly subfoveal choroidal thickness (SFCT) and peripapillary choroidal thickness (PPCT), is a key parameter in assessing ocular health and disease progression.
• The impact of acute IOP fluctuations on choroidal thickness requires further investigation.

Purpose of the Study:

• To investigate the effect of acute intraocular pressure (IOP) elevation, induced by a dark room prone provocative test (DRPPT), on subfoveal choroidal thickness (SFCT) and peripapillary choroidal thickness (PPCT).

Main Methods:

• A prospective cohort study involving 114 eyes from 65 individuals with an IOP elevation of at least 2 mm Hg during the DRPPT.
• Participants underwent a 2-hour dark room provocative test with their forehead on a desk.
• Tonometry and enhanced depth imaging spectral-domain optical coherence tomography were performed at baseline and post-test to measure IOP and choroidal thickness.

Main Results:

• The DRPPT provoked a significant IOP increase (10.1±10.9 mm Hg).
• Both SFCT and PPCT showed significant decreases (p<0.001) post-test.
• Multivariate analysis revealed that greater SFCT thinning correlated with higher IOP increase and shallower baseline anterior chamber depth; greater PPCT change correlated with higher IOP increase and thicker baseline choroidal thickness.

Conclusions:

• Acute IOP elevation induced by the DRPPT leads to a parallel decrease in both subfoveal and peripapillary choroidal thickness.
• These results indicate that choroidal thickness is dependent on current IOP levels.
• Clinicians should consider the influence of IOP when measuring choroidal thickness.