Disc excavation in dominant optic atrophy: differentiation from normal tension glaucoma

Area of Science:

• Ophthalmology: Focuses on optic nerve disorders and their differential diagnosis.
• Medical Imaging: Utilizes optic nerve photography for morphological assessment.
• Genetics: Investigates hereditary optic neuropathies like Dominant Optic Atrophy.

Background:

• Dominant optic atrophy (DOA), Kjer type, presents with optic nerve excavation, potentially mimicking normal tension glaucoma (NTG).
• Accurate differentiation is crucial for appropriate patient management and prognosis.
• This study aimed to identify distinct disc morphologic features of DOA.

Observation:

• A case series of nine patients with DOA evaluated between 1987 and 1996.
• Data included visual acuity, visual fields, color vision, intraocular pressure, and optic nerve photographs.
• Morphologic assessment focused on the optic disc and peripapillary zone.

Findings:

• Patients exhibited a mean age of 28 years, mild-to-moderate visual acuity reduction, and impaired color vision.
• Characteristic findings included a cup-to-disc ratio >0.5 in most eyes, temporal wedge-shaped excavation, and moderate-to-severe temporal optic disc pallor.
• Consistent pallor of the neuroretinal rim and peripapillary changes were noted.

Implications:

• Distinct clinical features aid in distinguishing DOA from NTG, including early onset, central vision loss with peripheral field sparing, specific optic disc pallor, and family history.
• Recognizing these features can prevent misdiagnosis and guide genetic counseling.
• Further research into the genetic basis and long-term progression of DOA is warranted.