Question of the Week

You are the chief resident on-call when one of your junior residents pages you about a clinic patient. The page reads “unusual lens pathology.” The patient is a cheerful, 75-year-old bearded man with a history of obesity, type 2 diabetes, and rosacea, but no prior ocular history. He is here for a routine visit. On exam, his visual acuity is 20/25 OU. He reports seeing glare around the stars, and he is particularly concerned about his ability to navigate at night, as his job depends on it. Fundus exam is normal. However, examination of the lens shows polychromatic needle-shaped crystalline deposits (see photo below) The colors of the crystals change depending on the angle of light; however on retroillumination, they appear opaque.

What is your diagnosis?

A. Christmas Tree Cataract

B. Asteroid Hyalosis

C. Snowflake Cataract

D. Mistletoe Cataract

E. Cholesterolosis bulbi

Answer

The correct answer is A.

The correct diagnosis is Christmas tree cataract (A), which is characterized by needle-like, polychromatic crystalline deposits within the deep cortex of the crystalline lens. These crystals refract light and display a spectrum of colors (such as pink, green, blue, red, and gold) depending on the angle of illumination, while appearing only faintly outlined on retroillumination. This pathology is thought to result from age-related degeneration of lens crystallin proteins associated with disordered calcium homeostasis. Although Christmas tree cataracts are classically associated with autosomal-dominant myotonic dystrophy, they can also occur idiopathically in elderly patients. Christmas tree cataracts are often minimally visually significant but may produce glare or cause difficulty navigating at night, which might be especially disturbing to our friend from the North Pole. Asteroid hyalosis (B) is incorrect because it is a condition of the vitreous where spherical calcium-lipid bodies are scattered throughout the posterior segment, producing a “stars in the night sky” effect. Snowflake cataracts (C) occur in younger patients with poorly controlled diabetes and appear as a white cataract with multiple cortical spokes. Mistletoe cataract (D) was just a distractor choice. Cholesterolosis bulbi (synchysis scintillans) is another condition of the vitreous that appears similar to asteroid hyalosis; however, in choleserolosis bulbi, the vitreous particles tend to settle at the bottom of the eye instead of being suspended in the vitreous.

Source: https://www.aao.org/eyenet/article/christmas-tree-cataract