OPA1 mutations associated with dominant optic atrophy influence optic nerve head size

Area of Science:

• Ophthalmology and Genetics
• Optic Nerve Head Morphology
• Dominant Optic Atrophy (DOA)

Background:

• Dominant optic atrophy (DOA) is a hereditary condition affecting the optic nerve.
• The OPA1 gene plays a crucial role in mitochondrial dynamics and optic nerve health.
• Understanding the impact of OPA1 mutations on optic nerve head (ONH) structure is vital for elucidating DOA pathogenesis.

Purpose of the Study:

• To investigate the influence of OPA1 gene mutations on the morphology of the optic nerve head (ONH) in patients diagnosed with dominant optic atrophy (DOA).
• To compare ONH parameters between DOA patients with OPA1 mutations and age-matched healthy controls.

Main Methods:

• A cross-sectional study design was employed.
• Twenty-eight patients with DOA and confirmed OPA1 mutations from 11 pedigrees were included.
• Optical coherence tomography (OCT) was used to analyze ONH morphology (area, vertical and horizontal diameters) in patients and 56 age-matched controls.

Main Results:

• DOA patients with OPA1 mutations exhibited significantly smaller optic disc area, vertical diameter, and horizontal diameter compared to controls.
• Specific OPA1 mutations showed varying effects on ONH size; two mutations were associated with normal ONH area.
• The missense mutation linked to the 'DOA plus' phenotype resulted in the smallest ONH measurements.

Conclusions:

• Patients with OPA1 gene mutations present with a significantly smaller optic nerve head (ONH) compared to the general population.
• The observed smaller ONH size in DOA patients may be mutation-specific, suggesting OPA1's role in ONH development and structure.
• These findings highlight a potential link between OPA1 gene mutations, reduced ONH size, and the pathogenesis of dominant optic atrophy.