Phacodonesis
Pronunciation: fay-ko-don-EE-sis
Tremulous movement of the crystalline lens due to weakened or torn zonular support fibers.
Full Definition
Phacodonesis is the clinical sign of lens tremor or oscillation that occurs when zonular fibers supporting the crystalline lens are damaged, stretched, or partially torn. This trembling movement becomes apparent during eye movements or when the eye is gently tapped. Phacodonesis indicates zonular instability and may be seen in conditions such as pseudoexfoliation syndrome, trauma, Marfan syndrome, or high myopia. The presence of phacodonesis alerts surgeons to potential complications during cataract surgery and may require modified surgical techniques or the use of capsular support devices.
Usage
Usage note: Often confused with iridodonesis, which refers specifically to iris tremor. Both may occur together.
In Context
- "Subtle phacodonesis was noted on slit-lamp examination, suggesting zonular weakness." — Clinical examination note
- "The presence of phacodonesis prompted the use of iris hooks during surgery." — Preoperative planning note