What is the management and treatment approach for Best disease (vitelliform macular dystrophy)?

Management of Best Disease (Vitelliform Macular Dystrophy)

There is no treatment available for Best vitelliform macular dystrophy itself; management consists of observation with regular monitoring and intravitreal anti-VEGF injections only when choroidal neovascularization develops. 1

Primary Management Strategy

Uncomplicated Best Disease

• Observation is the standard of care for patients with Best vitelliform macular dystrophy without complications 1
• No pharmacologic or surgical interventions have proven effective for the underlying disease process 1
• Regular monitoring is essential to detect complications, particularly choroidal neovascularization (CNV) 2, 3

When Neovascularization Develops

Intravitreal anti-VEGF injections are indicated when choroidal neovascularization occurs, which represents the primary vision-threatening complication 1, 2, 3

• Anti-VEGF therapy has demonstrated significant visual recovery in pediatric and adult cases with CNV secondary to Best disease 2, 3
• One case report documented vision improvement from 20/125 to 20/20 following anti-VEGF treatment for CNV in a 12-year-old patient 2
• Another pediatric case showed vision restoration to 20/20 after serial bevacizumab injections for subfoveal CNV 3

Diagnostic Confirmation

Clinical Characteristics to Identify

• Bilateral symmetrical vitelliform ("egg-yolk") lesions centered in the fovea on fundoscopy 1
• Positive family history consistent with autosomal dominant inheritance (though autosomal recessive forms exist) 1
• Serous detachment on OCT filled with hyperreflective material 1
• Hyperautofluorescence on fundus autofluorescence imaging 1
• Absent or markedly decreased light rise on electro-oculography (EOG) - this is pathognomonic 1
• No focal leakage on fluorescein angiography and no choroidal hyperpermeability on indocyanine green angiography 1

Genetic Testing

• BEST1 gene mutations confirm the diagnosis 1, 4, 2
• Testing is valuable even when parents have normal EOG results, as autosomal recessive forms exist 3
• Genetic counseling should be offered to affected families 4, 3

Monitoring Protocol

What to Watch For

• Development of choroidal neovascularization - the primary treatable complication 1, 2, 3
• CNV can occur bilaterally and consecutively, requiring vigilant monitoring of both eyes 2
• Progression through disease stages: previtelliform → vitelliform → pseudohypopyon → vitelliruptive → atrophic 5

Imaging Modalities

• Optical coherence tomography (OCT) to detect CNV and monitor structural changes 2, 3
• OCT angiography can identify early neovascular changes 2
• Fundus autofluorescence to track disease progression 1

Special Considerations

Pediatric Cases

• Amblyopia therapy should be implemented when visual acuity is asymmetric between eyes 3
• One case demonstrated improvement from 20/200 to 20/50 with amblyopia treatment in the fellow eye 3
• Early-onset cases may develop CNV at younger ages, requiring more frequent monitoring 2, 3

Differential Diagnosis Pitfalls

• Best disease can be misdiagnosed as toxoplasmosis when peripheral retinal lesions are present 2
• Distinguish from adult-onset foveomacular vitelliform dystrophy (smaller lesions <1 disc diameter, different FA pattern) 1
• Differentiate from vitelliform lesions secondary to age-related macular degeneration (presence of drusen) 1

Inheritance Patterns

• Most cases are autosomal dominant with variable penetrance 1, 4
• Autosomal recessive bestrophinopathy exists and may present earlier with more severe phenotype 1, 3
• Heterozygous carriers of recessive forms typically have normal EOG and minimal findings 3