STARGARDT’S DISEASE: A CASE REPORT
Apakama
AI (FMCOph)1,2, Chianakwalam EA
(FMCOph)2,
Igboegwu EE (FMCOph)2
1Department of Opthalmology,
Nnamdi Azikiwe University, Awka, Anambra State, Nigeria.
2Guinness Eye Centre, Onitsha,
Anambra State, Nigeria.
Author for Correspondence: akunneapakama@yahoo.com
Citation:
Apakama AI, Chianakwalam EA, Igboegwu EE.
Stargadt's Disease: A Case Report.
Orient Journal of Surgical Sciences. Vol.
2. January -
December 2021:
Page 35- 38
ABSTRACT
Stargardt's disease is a bilateral
symmetrical and progressive macular dystrophy that is transmitted in autosomal
recessive or dominant pattern. It usually starts between the ages of 6 and 20
years and typically leads to a rapid loss of central vision.
The authors describe clinical features of a 28-year old male
patient with fundus findings of Stargardt's disease whose symptoms were
said to have started about 19 years prior to presentation. Previously there has
been a single reported case in Nigeria.
We present this case that would be discussed along the lines
of presentation, pathophysiology, management. We introduce an innovative and
cost effective method of fundus examination using mobile phone technology.
Keywords:
Stargardt's; Central vision; Mobile Phone.
INTRODUCTION
Karl
Stargardt first described this condition in 1909 when he reported 7 patients
from two families with a recessively inherited disease characterized by macular
dystrophy surrounded by deep yellow-white lesions.1
Stargardt's
disease is caused by mutations in the ABCA4 gene, which encodes an
ATP-binding cassette (ABC) transporter protein expressed by rod outer segments.2
This genetic defect has a profound effect on the visual phototransduction
cycle.3 There is accumulation in the outer segment discs of of
N-retinyl-ethanolamine(A2E) which is a component of lipofuscin that is toxic to
the retinal pigment epithelium(RPE) and photoreceptors.4,5,6
Subsequently,
there is a degeneration of Photoreceptor and RPE cells by way of m e m b r a n
e p e r m e a b i l i t y, l y s o s o m a l dysfunction and detachment of
pro-apoptotic proteins leading to cell death and subsequent photoreceptor
dysfunction/loss.3,4,7
Stargardt's
disease is rather a rare condition. However it is the most commonly
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inherited childhood and adulthood macular dystrophy2,4
In the United States, it has an incidence of between 1 in 8000 and 1 in 10000.8
It has also been reported to account for 7% of all retinal dystrophies.7
Till date there has been only one reported case in 2 Nigerian siblings.3
Stargardt's disease is caused by
mutations in ABCA4 gene located on chromosome 1p21-p13.5 The most common
inheritance pattern is autosomal recessive. However it can also be autosomal
dominant.3,9 Age at presentation varies even among siblings with
onset being commonly in childhood and with another peak occurring in early
adulthood and less frequently in later adulthood.4 Evidence suggests
that the severity of the disease is associated with age of onset of the disease
with manifestation in childhood being more severe than with adult onset
disease.4
Clinically, it is a heterogenous disorder.4 Initial symptoms
include bilateral central visual loss characterised by blurred vision, central
scotomas and/or
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