Choroidal vascularity index in adults with different refractive status

Area of Science:

• Ophthalmology
• Optical Coherence Tomography
• Choroidal Imaging

Background:

• Refractive errors, including myopia and hyperopia, are associated with changes in ocular structures.
• The choroid, a vascular layer, plays a crucial role in ocular health and can be affected by refractive status.

Purpose of the Study:

• To analyze the structural differences of the choroid in adults with varying refractive statuses.
• To investigate the relationship between choroidal parameters and biometric measurements.

Main Methods:

• A prospective study involving 100 patients (ages 18-40) categorized into four refractive groups: low-to-moderate myopia, high myopia, hyperopia, and emmetropia.
• Enhanced depth imaging optical coherence tomography (EDI-OCT) was used to measure total choroidal area (TCA), luminal area (LA), stromal area (SA), and choroidal vascular index (CVI).
• Optical biometry measured anterior chamber depth (ACD), axial length (AL), and central corneal thickness (CCT).

Main Results:

• Significant differences in choroidal parameters were observed across the four refractive groups.
• Total choroidal area (TCA), luminal area (LA), and stromal area (SA) were highest in hyperopia and lowest in high myopia.
• Choroidal vascular index (CVI) was significantly lower in hyperopia compared to other groups, and showed no significant correlation with axial length or refractive error.

Conclusions:

• Choroidal vascular index (CVI) decreases with disruptions in emmetropia, observed in both myopia and hyperopia.
• In myopia, CVI reduction is linked to decreased luminal area, while in hyperopia, it's associated with increased stromal area.
• CVI is a robust parameter for evaluating choroidal changes related to refractive errors, independent of axial length and refractive error status.