Optical Coherence Tomography Angiography in Optic Nerve Drusen.

Area of Science:

• Ophthalmology
• Medical Imaging
• Neuro-ophthalmology

Background:

• Optic nerve head drusen (ONHD) can lead to visual field defects.
• Assessing optic nerve head (ONH) microcirculation is crucial for managing ONHD.
• Traditional methods may not fully capture ONH hemodynamics in ONHD.

Purpose of the Study:

• To evaluate the efficacy of optical coherence tomography angiography (OCT-A) in detecting optic nerve head (ONH) flow impairment.
• To assess microvascular changes in patients with ONHD using OCT-A.
• To correlate OCT-A findings with structural parameters and visual function.

Main Methods:

• Prospective case series including 13 patients with ONHD and 16 controls.
• Comprehensive ophthalmic examinations including best corrected visual acuity (BCVA), tonometry, and funduscopy.
• Spectral domain optical coherence tomography (SD-OCT) for structural analysis (ganglion cell complex [GCC] and retinal nerve fiber layer [RNFL]).
• OCT angiography (OCT-A) for quantitative assessment of ONH microvasculature (flow index and vessel density).
• Standard visual field testing (perimetry).

Main Results:

• Eyes with ONHD showed significantly lower flow index and vessel density compared to controls.
• Ganglion cell complex (GCC) and retinal nerve fiber layer (RNFL) parameters were reduced in ONHD patients.
• GCC parameters demonstrated a significant correlation with OCT-A findings (p < 0.05).
• No significant correlation was observed between RNFL and OCT-A parameters.
• Visual field parameters did not differ significantly between groups.

Conclusions:

• OCT-A serves as an objective tool for analyzing microvascular changes in the optic nerve head.
• OCT-A can aid in the diagnosis and monitoring of flow impairment associated with ONHD.
• The findings support OCT-A's utility in understanding the pathophysiology of ONHD.