2. Case Report
Best’s Vitelliform Macular Dystrophy
Introduction
Best's disease, also termed vitelliform macular dystrophy, is an autosomal dominant
disorder, which classically presents in childhood with the striking appearance of a yellow or
orange yolk like lesion in the macula. Dr Franz Best, a German ophthalmologist, described
the first pedigree in 1905 (1).
Many individuals with Best disease initially are asymptomatic, with fundus lesions noted on
examination. Visual symptoms can include decreased acuity (blurring) and metamorphopsia.
These symptoms may worsen if the disease progresses to the atrophic stage.
Case Report
A 13year old man was first seen in July 2011 in Grarbet Eye Hospital out patient department
with complain of gradual reduction of vision and presence of blind spots in the centre of his
visual field in his both eyes. He had otherwise unremarkable anterior and posterior ocular
findings and did not have any systemic disease.
Ocular examination showed full extra ocular movements and his visual acuity was
6/36 in his both eyes and there was no improvement with refraction. The amsler grid test
in this patient revealed the presence of bilateral severe metamorphopsia. Hanson visual
field (VF) testing showed central scotoma bilaterally. Pelli-Robson contrast sensitivity
test showed decreased contrast sensitivity perception in both eyes. Intra ocular pressures
were 14mm of mercury in both eyes (non-contact tonometer). There wasn’t relative
afferent pupillary defect in his both eyes. On slit lamp examination anterior
segment was unremarkable. A dilated fundus examination revealed large round
atrophic macular dystrophy of 2.5-3 disc diameters involving the whole macula of
both eyes. Both optic discs were pink and the retinal vasculatures were also normal.
3. On the basis of history and examination, he was diagnosed a case of vitelliform
macular dystrophy. There was evidence of atrophic macular scarring as noted from the
images taken by fundus camera (Figure1). Electro oculograms (EOG) was not performed
because of lack of electrophysiological test facilities. After a year, patient’s Vision in
his both eyes was unchanged. His father and mother were screened after a year and
have VA of 6/6 and normal macula on funduscopy examination in both direct
ophthalmoscope and Fundus camera.
Figure 1: Right (top) and left (down) fundus photographs of the bilateral atrophic
stage of the patient.
4. Discussion
Best’s disease is one of the rare an autosomal dominant macular dystrophy of variable
penetrance in which lipofuscin granules accumulate in retinal pigment epithelial cells (2, 3).
It typically affects young patients in whom a macular lesion gradually evolves through
several characteristic stages (4).
Dutmann classified the evolution of Best disease in different stages (5) which has been
modified by Mohler and Fine in 1981:
Stage 1 Normal fundus, abnormal EOG
Stage 2: Pre-Vitelliform stage
Stage 3: Vitelliform stage (''sunnyside-up egg yolk'')
Stage 4: ''scrambled egg '' stage
Stage 5: Cyst stage
Stage 6: '' Pseudohypopyon'' stage
Stage 7: Atrophic stage
Previous study showed that Best Vitelliform degeneration is an isolated disease with no
systemic associations. However, there is a case report (6) in which Lesions in Best disease is
restricted to the eye. Abnormalities in the eye result from a disorder in the retinal pigment
epithelium (RPE). A dysfunction of bestrophin results in abnormal fluid and ion transport by
the RPE (7). Lipofuscin (periodic acid-Schiff [PAS] positive) accumulates within the RPE
cells and in the sub-RPE space, particularly in the foveal area. The RPE appears to have
5. degenerative changes in some cases, and secondary loss of photoreceptor cells has been
noted (3).
Visual acuity in Best Vitelliform degeneration is generally good in the Vitelliform stage. It
is only with the onset of Vitelliruptive stage when the vision starts to
reduce. This occurs due to retinal pigment epithelial atrophy. According to Fishman GA (8)
and colleagues, fall in visual acuity is more in patients above 50 years of age.
This disease has a wide range of state and in doubtful cases Electro-oculography is the
diagnostic test. Patients usually maintain visual acuity better than 6/12 through
the vitelliruptive stage (4). It is in the atrophic stage that visual acuity can
deteriorate to the level of legal blindness because of retinal pigment epithelial
cell and photoreceptor disruption and death. Similarly, lesions in Best’s disease
are frequently single and central but there are few reports (3) which describe multiple
peripheral lesions outside the macula and posterior pole.
There is no effective treatment available to slow the progression of Best’s disease.
Antioxidant supplementation might have a theoretical benefit, given the role of free
radicals in the formation of lipofuscin (9).
6. Reference
1. Best F. Ubereine hereditary Maculaaffektion. Beitrage Zur Vererbungslehre.
Augenheikd. 1905; 13: 199.
2. Frangieh GT, Green W, Fine S. A histopathologic study of Best’s macular
dystrophy. Arch Ophthalmol 1982 ; 100 : 1115-1121.
3. Weingeist T, Kobrin J, Watzke R. Histopathology of Best’s macular dystrophy.
Arch Ophthalmol 1982 ; 100 : 1108-1114.
4. Mohler CW, Fine S. Long-term evaluation of patients with Best’s vitelliform
dystrophy. Ophthalmology 1981 : 88 : 688.
5. Deutmann AF. The hereditary dystrophies of the posterior pole of the eye. Assen
the Netherlands: Van Gorcum Comp. N.V., 1971.
6. McLoone EM, Buchanan TA. Unusual macular lesions in a patient with
neurofibromatosis type 1. Int Ophthalmol. 2005; 26: 115-7.
7. Hartzell HC, Qu Z, Yu K, Xiao Q, Chien LT. Molecular physiology of bestrophins:
7. multifunctional membrane proteins linked to best disease and other retinopathies.
Physiol Rev. Apr 2008;88(2):639-72.
8. Fishman GA, Baca W, Alexander KR, et al. Visual acuity in patients with best
vitelliform macular dystrophy. Ophthalmology. 1993; 100: 1665-70.
9. Schmitz-Valckenberg S, Holz FG, Bird AC, Spaide RF. Fundus autoluorescence
imaging: review and perspectives. Retina.2008;28:385-409.
