Macular Microvasculature in High Myopia without Pathologic Changes: An Optical Coherence Tomography Angiography Study

Area of Science:

• Ophthalmology
• Medical Imaging
• Retinal Vascular Diseases

Background:

• High myopia is a significant risk factor for various ocular pathologies.
• Understanding microvascular alterations in the macula is crucial for managing high myopia complications.

Purpose of the Study:

• To investigate macular microvasculature changes in high myopia using optical coherence tomography angiography (OCTA).
• To analyze the correlation between these microvascular changes and ocular structural parameters.

Main Methods:

• Optical coherence tomography angiography (OCTA) was used to measure the foveal avascular zone (FAZ) area and parafoveal vessel density in superficial and deep retinal plexuses.
• Retinal thickness, subfoveal choroidal thickness, and ocular characteristics were assessed.
• Bennett's formula was applied to correct for magnification effects on the FAZ area.

Main Results:

• Eyes with high myopia exhibited a significantly larger FAZ area compared to controls (p=0.023).
• Superficial parafoveal vascular density was significantly decreased in myopic eyes (p=0.007), while deep parafoveal density showed no significant difference (p=0.226).
• Parafoveal inner retinal thickness was significantly reduced in myopic eyes (p=0.023), correlating with superficial parafoveal vascular density.

Conclusions:

• Macular microvasculature alterations, including enlarged FAZ and reduced superficial vascular density, are present in high myopia.
• These changes are associated with ocular axial elongation and altered retinal thickness profiles.
• The findings suggest that axial elongation in myopia contributes to macular microvascular network changes.