Acute conformational changes in the optic nerve head with rapid intraocular pressure elevation: implications for...

Area of Science:

• Ophthalmology
• Optic Nerve Head Imaging
• Glaucoma Research

Background:

• Intraocular pressure (IOP) is a key risk factor for glaucoma.
• Optic disc morphology changes are indicative of glaucomatous damage.
• Understanding acute IOP effects is crucial for diagnosing and managing optic nerve conditions.

Purpose of the Study:

• To investigate the impact of acute intraocular pressure (IOP) elevation on optic disc morphology.
• To assess reversibility of IOP-induced optic nerve head changes.

Main Methods:

• Ophthalmodynamometry was used to transiently elevate IOP in healthy eyes.
• Confocal scanning laser ophthalmoscopy (Heidelberg Retinal Tomograph II) captured optic nerve head topography.
• IOP measurements and optic disc parameters were recorded before, during, and after IOP elevation.

Main Results:

• Significant alterations in rim area, rim volume, cup area, cup volume, cup-to-disc ratio, mean cup depth, maximum cup depth, and retinal nerve fiber layer (RNFL) thickness were observed during elevated IOP (P < .05).
• Most parameters reverted to baseline after IOP normalization (P > .2).
• Mean RNFL thickness showed a persistent significant change post-IOP elevation (P = .03).

Conclusions:

• Acute elevation of intraocular pressure induces quantifiable changes in optic nerve head topography.
• These findings highlight the dynamic nature of optic disc structures under pressure variations.
• Reversibility of RNFL thickness warrants further investigation in the context of transient IOP changes.