Atlas of Ophthalmology

Christmas tree cataract

Christmas tree cataract
The Christmas tree cataract is highly reflective, iridescent and polychromatic. They look like little needles in the eye going in all directions and assume the shape of a Christmas tree. The needles change color when the angle of the incident light is changed. In Christmas tree cataract,the adjacent areas of the lens remain clear. It has been said that with increasing age there is degradation of the peptides and amino acids within the lens by endopeptidases. There is an increase in calcium ions and this local increase in calcium ions stimulates the endopeptidases resulting in protein breakdown. The breakdown products are subsequently deposited in the lumen of the reticular meshwork forming the Christmas tree cataract. The crystals are thus taken to be made of cystine (an amino acid). Accumulation of cystine beyond the point of crystallization causes the formation of needles that gives the fascinating appearance of the Christmas tree in the eye.
NGOUNOU, FAUSTIN, M.D., ACHA, BAFOUSSAM, CAMEROON; PATEL, RAJESH, M.D., ACHA, DOUALA, CAMEROON; ALICE, NCHIFOR, M.D., ACHA, BAFOUSSAM, CAMEROON; FRU, ELISEUS, M.D., ACHA, DOUALA, CAMEROON
H25.8
Lens -> Senile Cataract -> Mixed Cataract
9099
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