A cherry-red spot is a finding in the macula

Macula

The macula or macula lutea is an oval-shaped highly pigmented yellow spot near the center of the retina of the human eye. It has a diameter of around 5 mm and is often histologically defined as having two or more layers of ganglion cells...

 of the eye

Eye

Eyes are organs that detect light and convert it into electro-chemical impulses in neurons. The simplest photoreceptors in conscious vision connect light to movement...

 in a variety of lipid storage disorders and in central retinal artery occlusion.
It describes the appearance of a small circular choroid shape as seen through the fovea centralis.
Its appearance is due to a relative transparency of the macula; storage disorders cause the accumulation of storage material within the cell layers of the retina, however, the macula, which is relatively devoid of cellular layers, does not build up this material, and thus allows the eye to see through the macula to the red choroid below.

The sign was first described by Warren Tay, founding member of the British Ophthalmological Society, in 1881, with reference to a patient with Tay-Sachs disease.

The cherry red spot is seen in central retinal artery occlusion, appearing several hours after the blockage of the retinal artery occurs. The cherry red spot is seen because the macula receives its blood supply from the choroid artery while the surrounding retina is pale due to retinal artery infarction. It is also seen in several other conditions, classically Tay-Sachs Disease

Tay-Sachs disease

Tay–Sachs disease is an autosomal recessive genetic disorder...

, but also in Niemann-Pick Disease

Niemann-Pick disease

Niemann–Pick disease refers to a group of fatal inherited metabolic disorders that are included in the larger family of lysosomal storage diseases .-Signs and symptoms:Symptoms are related to the organs in which they accumulate...

, Sandhoff disease

Sandhoff disease

Sandhoff disease, also known as Sandhoff-Jatzkewitz disease, variant 0 of GM2-Gangliosidosis or Hexosaminidase A and B deficiency, is a lysosomal genetic, lipid storage disorder caused by the inherited deficiency to create functional beta-hexosaminidases A and B...

, and mucolipidosis

Mucolipidosis

Mucolipidosis is a group of inherited metabolic disorders that affect the body's ability to carry out the normal turnover of various materials within cells....

.

Differential Diagnosis of Cherry Red Spot at Macula

1. Metabolic Storage Diseases:
   1. Mucopolysaccharidosis
   2. Hurler's disease
   3. Tay-Sachs disease
      Tay-Sachs disease
      Tay–Sachs disease is an autosomal recessive genetic disorder...
      
      
   4. MPS VII
   5. Farber's disease
   6. GM1 gangliosidoses
      GM1 gangliosidoses
      The GM1 gangliosidoses are caused by a deficiency of beta-galactosidase, with resulting abnormal storage of acidic lipid materials in cells of the central and peripheral nervous systems, but particularly in the nerve cells.-Early infantile GM1:...
      
      
   7. Juvenileeroid
   8. Niemann Pick's disease
   9. Sandoff's disease
   10. Shprintzen-Goldberg syndrome
       Shprintzen-Goldberg syndrome
       Shprintzen-Goldberg syndrome is a craniosynostosis syndrome caused, at least in some cases, by mutation in the FBN1 gene....
       
       
   11. Lysosomal Storage Diseases
2. Congenital Developmental Diseases : Amaurosis, congenital, Leber's
3. Hereditary/ Familial:
   1. Hallervorden Spatz disease
   2. leukodystrophy, Krabbe's
4. Degenerative: Metachromatic leukodystrophy
5. Vascular: central retinal artery occlusion
6. Drugs:
   1. Quinine toxicity
   2. Dapsone toxicity
7. Poisoning:
   1. Carbon monoxide
   2. Methanol