A “dropped nucleus” means fragments of the cataract (lens material) fall through a posterior capsule tear into the vitreous cavity at the back of the eye. This occurs when PCR happens before the lens material has been fully removed, especially in dense cataracts where large fragments remain ¹.
The posterior capsule normally acts as a floor. When it tears, gravity and fluid currents can carry lens pieces backward. This does not mean the surgeon “lost control”; it reflects an anatomical barrier failure during a dynamic, fluid-based procedure.
Why it matters:
- Lens fragments in the vitreous can provoke significant inflammation
- They can raise intraocular pressure
- They increase the risk of cystoid macular oedema and, rarely, retinal detachment
Management depends on fragment size and inflammation. Small fragments may be observed with intensive anti-inflammatory treatment. Larger or symptomatic fragments usually require pars plana vitrectomy by a vitreoretinal surgeon to remove the retained lens material ¹ ³.
Timing is tailored. Early surgery can reduce inflammation, but operating through a cloudy cornea can increase risk. Evidence suggests outcomes are good with timely vitrectomy, and brief delays to improve visibility may be clinically sensible ².
The goal is to restore a quiet eye and protect the retina.
References
- Kim JE, Flynn HW Jr, Smiddy WE, Murray TG, Rubsamen PE. Retained lens fragments after phacoemulsification. Ophthalmology. 1994;101(11):1827-1832.
- Scott IU, Flynn HW Jr, Dev S, Shaikh S, Mittra RA, Arevalo JF, Miller D. Functional and anatomic outcomes following vitreoretinal surgery for retained lens fragments. Ophthalmology. 2003;110(8):1567-1572.
- Vanner EA, Stewart MW. Vitrectomy timing for retained lens fragments after cataract surgery. Retina. 2011;31(8):1531-1538.
Related Topics
- What is Posterior Capsule Rupture?
- Why is my risk of retinal detachment increased after PCR?
- Why is there increased cystoid macular oedema (CMO) after PCR?
- Why might my eye pressure rise after PCR?
- When will I be seen again after PCR?
- What does PCR mean for my bilateral surgery?
- Will my vision be ok after posterior capsule rupture?
- Will my vision be ok after dropped nucleus surgery following PCR?
- How long will the operation take if PCR occurs?
- Can I go to Moorfields for a second opinion instead?
- If I seek a second opinion, can I still have my corrective surgery at Blue Fin Vision®?
- What happens to my fees if I cancel the second eye after PCR?
- Is my risk higher for the second eye if I had PCR in the first?
- What is anterior vitrectomy and why is it performed after PCR?
- What is a three-piece monofocal lens and why is it used after PCR?
- What is a sulcus supplementary (Sulcoflex) lens?
- What is dropped nucleus and why does it happen after PCR?
- What is expulsive suprachoroidal haemorrhage and why is it mentioned with PCR?
- Why does pseudoexfoliation increase the risk of PCR?
- Why do very dense cataracts increase the risk of PCR?
- Is posterior capsule rupture negligence?
