Average Age of Onset for Macular Telangiectasia Type 2
The average age of onset for Macular Telangiectasia Type 2 (MacTel 2) is typically between 50 and 69 years of age, with the majority of patients (76%) becoming symptomatic during the sixth or seventh decade of life. 1
Epidemiology and Age Distribution
Macular Telangiectasia Type 2 is an acquired bilateral neurodegenerative macular disease that typically manifests during middle age. The specific age distribution shows:
- 58% of patients become symptomatic before age 60 1
- The highest frequency of symptom onset (76%) occurs between ages 50-69 1
- The disease usually manifests during the fourth to sixth decades of life 2
Clinical Presentation and First Symptoms
The initial presentation of MacTel 2 is characterized by specific symptoms that help identify the condition:
- Reading difficulty is the most common first symptom (79% of patients) 1
- Metamorphopsia (visual distortion) is the second most common initial symptom (12%) 1
- The disease is often asymptomatic in early stages, making detection challenging without careful fundus examination
Disease Characteristics
MacTel 2 has distinct features that differentiate it from other macular conditions:
- Bilateral involvement is typical
- Minimal dilatation of parafoveal capillaries with graying of the affected retinal area
- Lack of lipid exudation
- Right-angled retinal venules
- Refractile deposits in the superficial retina
- Hyperplasia of the retinal pigment epithelium
- Foveal atrophy
- Potential development of subretinal neovascularization in advanced stages 2, 3
Diagnostic Considerations
Diagnosis of MacTel 2 has historically been delayed, with a median delay of:
- 7 years before 2005
- 1 year after 2005 (due to improved awareness and diagnostic techniques) 1
Visual Prognosis
Ten years after symptom onset, visual acuity outcomes vary:
- 35% of patients maintain good distance visual acuity (≥20/25) in their better eye
- 17% experience moderate to severe visual impairment (≤20/50) 1
Diagnostic Imaging
Multiple imaging modalities help confirm the diagnosis:
- Fluorescein angiography: Shows deep intraretinal hyperfluorescent leakage, typically beginning in the temporal parafoveal area
- Optical coherence tomography (OCT): Reveals intraretinal hyporeflective spaces not associated with retinal thickening
- Fundus autofluorescence: Demonstrates characteristic macular pigment depletion 3, 4
The prevalence of MacTel 2 may be underestimated and has been reported to be as high as 0.1% in persons 40 years and older 5, making awareness of its typical age of onset important for timely diagnosis and management.