Idiopathic bilateral cataracts occur in many cases of CTX

Idiopathic bilateral cataracts represent a key opportunity to diagnose CTX

In a systematic review of selected case series, the prevalence of cataracts in CTX patients was 88%.¹ In CTX, cataracts are typically early-onset and bilateral, although the exact age of onset varies. Cataracts often present between the ages of 4 and 18 years.² They usually develop in the first 3 decades of life, although a smaller number of patients develop cataracts later in life, after neurologic symptoms are already advanced.^2,3 Because idiopathic bilateral cataracts are relatively rare, it may be possible to test all such cases to identify or diagnose CTX.

Causes of idiopathic bilateral cataracts

In CTX, cataracts are caused by a buildup of cholestanol in the lens.⁴ Among patients with a known neurologic disorder presenting with early-onset cataracts, CTX may be the second most common cause after myotonic dystrophy.⁵

Other causes of bilateral cataracts in children include: galactosemia,⁶ diabetes,⁷ uveitis associated with chronic juvenile arthritis,⁸ history of chronic corticosteroid use⁹ or whole body irradiation,¹⁰ hypoglycemia,^11,12 or hypocalcemia.^13,14

Fleck lenticular cataract morphology in CTX¹⁵

Although virtually all reported cases of CTX feature cataracts, very few cases describe the appearance or characteristics of the cataracts.^1,15 It is possible that CTX cataracts may be somewhat distinctive in their appearance or morphology.¹⁵ The cataracts seen in one family of 3 affected siblings had a distinct “fleck” appearance.¹⁵ The nature of the crystalline lens opacities has been described as zonular, anterior, or posterior opacities that were like spokes, dots, flecks, or snowflakes, or a combination of the above.¹⁵