Choroidal vascularity index in hereditary optic neuropathies

Area of Science:

• Ophthalmology
• Neuro-ophthalmology
• Vascular Biology

Background:

• Leber hereditary optic neuropathy (LHON) and dominant optic atrophy (DOA) are inherited optic neuropathies that can lead to vision loss.
• The choroid, a vascular layer of the eye, plays a crucial role in retinal health.
• Assessing choroidal structure may provide insights into the pathophysiology of optic neuropathies.

Purpose of the Study:

• To evaluate the choroidal vascularity index (CVI) in patients with LHON and DOA.
• To compare CVI between LHON patients, DOA patients, and healthy controls.

Main Methods:

• A retrospective study included 48 eyes from LHON patients, 48 from DOA patients, and 48 from healthy controls.
• Optical coherence tomography (OCT) was used to measure choroidal parameters, including subfoveal choroidal thickness (Sub-F ChT), mean choroidal thickness (ChT), total choroidal area (TCA), and luminal choroidal area (LCA).
• The choroidal vascularity index (CVI) was calculated as the ratio of LCA to TCA.

Main Results:

• Choroidal thickness (Sub-F ChT and Mean ChT) was reduced in DOA patients compared to controls, and Mean ChT was also reduced in LHON patients, though not significantly.
• No significant differences were found in total choroidal area (TCA), luminal choroidal area (LCA), or stromal choroidal area (SCA) among the three groups.
• The choroidal vascularity index (CVI) showed no statistically significant differences between LHON patients, DOA patients, and healthy controls.

Conclusions:

• The choroidal vascularity index (CVI) is preserved in patients with dominant optic atrophy (DOA) and Leber hereditary optic neuropathy (LHON).
• This suggests that the choroidal vascular structure is not irreversibly compromised, even in the chronic stages of these optic neuropathies.