Causes
As a mitochondrial genetic disorder, Leber Hereditary Optic Neuropathy (LHON) is caused by mutations in mitochondrial DNA, which are inherited maternally (from the mother). Mutations in the mitochondrial genes MT-ND1, MT-ND4, and MT-ND6 are most common, because mitochondrial function and energy production are essential for cells, particularly the optic nerve.
Symptoms
It usually appears between the ages of 15 and 35, and symptoms may include:
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It often begins in one eye, then affects the other within weeks or months.
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A loss of sharp, detailed central vision, while peripheral vision is usually preserved.
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Having difficulty distinguishing colors, particularly red and green.
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Pseudodisc Edema: Swelling of the optic nerve head that may be observed during an eye examination.
Diagnosis
There are several steps involved in diagnosing LHON:
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The ophthalmologist will examine your eyes thoroughly, including visual acuity tests, color vision tests, and dilated fundus examinations.
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OCT (Optical Coherence Tomography): An imaging technology that provides detailed images of the optic nerve and retina.
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Identifying mitochondrial DNA mutations associated with LHON through genetic testing.
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Assessing the family history of vision problems and mitochondrial disorders to support the diagnosis.
Treatment
There is currently no cure for LHON, but various treatments and interventions may help manage symptoms and improve quality of life:
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Some patients may benefit from idebenone, a synthetic coenzyme Q10 analog.
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Patients with vision loss can benefit from vision aids, occupational therapy, and mobility training.
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Providing genetic counseling to affected individuals and their families regarding the nature of the disorder, inheritance patterns, and reproductive options.
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Avoid excessive alcohol consumption and smoking, as these can exacerbate the condition.
Prevention
Making informed reproductive choices and understanding genetic risks are essential to preventing LHON:
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A genetic counselor can help individuals with a family history of LHON understand their risk of transmitting the disease.
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A prenatal test may be able to detect mitochondrial DNA mutations associated with LHON in some cases.
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Various reproductive options are available for affected individuals, including in vitro fertilization (IVF) with mitochondrial replacement therapy.
Conclusion
A genetic disorder, Leber Hereditary Optic Neuropathy primarily affects the optic nerve, causing sudden vision loss in young adults. Mutations in mitochondrial DNA cause the condition. Diagnosis involves ophthalmological examinations, OCT imaging, genetic testing, and family history assessment. Symptoms include sudden vision loss, central vision loss, and color vision deficiency. Treatments such as idebenone, supportive care, and lifestyle modifications may help manage symptoms. Genetic counseling and prenatal testing are important preventative measures for at-risk families.
