Lateral Geniculate Nucleus Volume Assessment Using Linear Mixed Model in Moderate and Advanced Retinitis Pigmentosa

Area of Science:

• Neuroscience
• Ophthalmology
• Medical Imaging

Background:

• Retinitis pigmentosa (RP) is a group of inherited diseases that cause progressive vision loss.
• The lateral geniculate nucleus (LGN) is a key relay center in the visual pathway, potentially affected by RP.
• Understanding LGN volume changes in RP may offer insights into disease progression and visual impairment.

Purpose of the Study:

• To compare the volume of the lateral geniculate nucleus (LGN) in patients with moderate versus advanced retinitis pigmentosa (RP).
• To investigate the influence of age, sex, and LGN symmetry on LGN volume in RP patients.
• To explore potential correlations between LGN volume and visual acuity or retinal thickness.

Main Methods:

• Utilized 7 Tesla MRI to examine the brains of 13 moderate and 18 advanced RP patients.
• Manually measured left and right LGN volumes using ITK-SNAP software.
• Applied a linear mixed statistical model to analyze LGN volume in relation to disease stage, age, sex, and LGN symmetry.

Main Results:

• No significant difference in LGN volume was found between moderate and advanced RP groups after adjusting for age and sex.
• The right LGN volume was significantly larger than the left LGN volume in both RP groups (p < 0.001).
• A trend suggested LGN volume decreases with age (p = 0.060), with no significant gender predilection.
• In the moderate RP group, left LGN volume correlated with visual acuity (ρ = 0.64) and central retinal thickness (ρ = 0.71).

Conclusions:

• LGN volume does not significantly differ between moderate and advanced stages of RP.
• A consistent asymmetry exists, with the right LGN being larger than the left in RP patients, independent of gender.
• Left LGN volume shows a correlation with visual acuity and central retinal thickness in moderate RP, suggesting potential clinical relevance for future RP management.