Oman Journal of Ophthalmology

CLINICAL IMAGE
Year
: 2011  |  Volume : 4  |  Issue : 2  |  Page : 95--96

Macular dystrophy in a young male with corneal dystrophy among sisters


George Zachariah, Thara Idiculla, BR Keshav, Mahmood Nasser 
 Department of Ophthalmology, Sur Hospital, Oman

Correspondence Address:
George Zachariah
Sur Hospital, 995/411
Oman




How to cite this article:
Zachariah G, Idiculla T, Keshav B R, Nasser M. Macular dystrophy in a young male with corneal dystrophy among sisters.Oman J Ophthalmol 2011;4:95-96


How to cite this URL:
Zachariah G, Idiculla T, Keshav B R, Nasser M. Macular dystrophy in a young male with corneal dystrophy among sisters. Oman J Ophthalmol [serial online] 2011 [cited 2020 Sep 21 ];4:95-96
Available from: http://www.ojoonline.org/text.asp?2011/4/2/95/83664


Full Text

Stargardts macular dystrophy is a genetic disorder with an estimated incidence of 1 in 10,000. It is almost always inherited as an autosomal recessive disorder, with only 10% cases resulting from dominant mode of inheritance. Mutations in Stargardts disease gene ABCA4 can result in different macular dystrophies like fundus flavimaculatus, cone rod dystrophy and autosomal recessive retinitis pigmentosa. [1] Variable presentations of different macular dystrophies in the members of same family are reported, but two distinct dystrophies affecting cornea and retina among siblings have rarely been reported.

A 26-year-old man presented with history of bilateral progressive visual loss. He denied significant difference in day and night vision. His parents were first-degree relatives. Out of 11 siblings, 5 sisters were affected with severe corneal dystrophy from early childhood. Four sisters and one brother were unaffected by any ocular or systemic disorder.

His best corrected visual acuity was 6/60 OD, 5/60 OS. There was no nystagmus. Color vision was normal. Ophthalmic examination was unremarkable except for paramacular retinal flecks and macular atrophy in right eye and flecks with atrophic maculopathy in left eye on fundus examination [Figure 1].{Figure 1}

Fluorescein angiography showed hyperfluorescent flecks and macular atrophy OD and a large hyperfluorescent window defect at the macula OS [Figure 2]. Dark choroid was not seen OU.{Figure 2}

Optical Coherence Tomography (OCT) showed decreased foveal thickness and atrophy of macula OU along with Retinal pigment epithelial atrophy OS [Figure 3].{Figure 3}

 Discussion



Stargardts disease is usually diagnosed in individuals under the age of 20. It is symptomatically similar to age-related macular degeneration. Juvenile macular degeneration was first reported in 1901 by German ophthalmologist Karl Stargardt, from whom the disease gets its name. The progressive loss of central vision to legal blindness level is variable. [2] Peripheral vision and night vision are not lost for most people, but color vision would be affected in late stage. In 1997, researchers isolated the ABCA4 gene of chromosome 1p21 for Stargardts disease. ABCA4 gene produces a protein involved in energy transport to and from photoreceptor cells in retina. Mutations in ABCA4 gene, which cause Stargardts disease, produce a dysfunctional protein that cannot perform its transport function. The non-functional ABCA4 protein permits accumulation of yellow, lipid-rich waste material, lipofuscin, in retinal pigment epithelial cells. The focal accumulation of lipofuscin causes flecks and eventual dysfunction and death of photoreceptors, causing atrophy in the macula. Diffuse accumulation of lipofuscin in entire RPE cell layers will partially block the normal choroidal fluorescence. Dark choroid is seen on fluorescein angiography in 85% of cases only. Lafaut, in his case report of Stargardts disease, noticed that dark choroid was not seen in either eye. [3] Our case also had a missing dark choroid on fluorescein angiography.

Appropriate low vision aids along with genetic counseling are the present treatment modalities.

FDA approval for the trial of human embryonic stem cell injection into the eye is a ray of hope for Stargardts patients.

Hereditary disorders are inherited in different ways. Every person inherits two copies of each gene, one from each parent. Transmission of disease can vary from person to person, even within the same family. [4],[5] Genetic research has identified nearly about 500 genes that contribute to inherited eye diseases. The inheritance pattern of Stargardts is mostly autosomal recessive although a small number may be autosomal dominant. Corneal dystrophies are mostly autosomal dominant except macular dystrophy and congenital hereditary endothelial dystrophy type-2. Coexistence of two distinct inherited eye disorders in this family may be an expression of two genetic disorders and may be coincidental. Further genetic research and histopathology studies may provide a better therapeutic strategy.

References

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