1) A nucleus drop occurs when part or all of the lens nucleus falls into the vitreous cavity during cataract surgery. It has a low incidence rate of around 0.3%. 2) Risk factors include preexisting conditions like pseudoexfoliation or zonular weakness, as well as complications during surgery such as tears in the posterior capsule or zonules. 3) Definitive management involves a pars plana vitrectomy to remove the dropped nucleus and any remaining vitreous gel. This helps minimize complications like uveitis, glaucoma, or retinal detachment.

1. NUCLEUS DROP
Dr Dhwanit Khetwani

2. WHAT IS A NUCLEUS DROP?
Loss of a part or the whole Lens nucleus in the vitreous cavity.
INCIDENCE –The Incidence of nucleus drop following a PCR is 0.3% (2-3/1000)
Operations/year for Phacoemulsification Surgery.

3. RISK FACTORS
PREOPERATIVE
■ Pseudoexfoliation of the lens capsule with zonular weakness visible preoperatively
■ Mature or Hypermature cataracts in eyes in which the posterior capsule may be thin
and the zonules weak
■ Previous trauma in eyes in which the posterior capsule or zonule may be damaged
■ Visible zonular weakness or absence preoperatively
■ A small eye with a crowded anterior segment, a large eye with a loose capsule.
■ Previous vitrectomy
■ Marfan's syndrome and posterior polar cataracts (although these conditions rarely
lead to a lost nucleus)

4. INTRAOPERATIVE
■ Visible tears in the Posterior capsule during hydrodissection secondary to nicks in the
anterior capsule or anterior capsular block
■ Occult tears of the posterior capsule during hydrodissection secondary to anterior
capsular block
■ The Radial Progression of an Anterior CapsularTear
■ The Equatorial Or Posterior Rupture of the capsule by the phaco tip
■ A posterior capsule torn by an instrument or a sharp, mature nuclear fragment
during a surge in phaco energy
■ A zonular dialysis larger than 3 clock hours

5. COMPLICATIONS OF DROPPED NUCLEUS
Elevated
Intraocular
Pressure
Uveitis
Corneal
Oedema
Cystoid
Macular Oedema
Retinal
detachment
Hence, proper management of vitreous loss and retained lens fragments is the
most important factor, influencing theVisual Outcome .

6. ■ Elevated Intraocular Pressure- This could be due to clogging ofTrabecular Meshwork
with lens Proteins, Macrophages and other inflammatory cells. It generally is more
common in eye undergoing delayedVitrectomy
■ Intraocular Inflammation- The lens protein causes severe intraocular reaction.The
severity of inflammation is directly proportional to the volume of lens matter
Retained.
■ Corneal Oedema- (33-85% in cases with retained lens fragment) Increased
Intraoperative Manipulation, Postoperative inflammatory reaction and raised IOP are
three important factors contributing to CornealOedema.
■ Cystoid Macular Oedema- it has been reported in (7-41%) patients with retained
nuclear fragments in posterior segment.
■ RetinalTears/Detachment Reported in (7-8%) of cases. It can develop after Pars Plana
Vitrectomy to remove dislocated Nuclear fragment.

8. Primary Management by the Anterior
Segment Surgeon
■ First step in management is to recognize posterior capsular (PC) tear early. Early
recognition reduces the chances of vitreous loss and dropped fragment.
■ Signs of Posterior Capsular rupture
– Sudden deepening of anterior chamber, with slight dilation of pupil.
– Sudden, transitory appearance of a red reflex peripherally.
– difficulty in holding nuclear fragments with phacoemulsification tip,
– descent of the nucleus away from the phacoemulsification tip
– Pupillary snap sign

9. Deciding On Further Course Of Surgery.
■ If Retained Nucleus Is Small and NoVitreous Prolapse with Adequate Capsular Support,
then continuing with the phaco emulsification depends upon surgeons’ choice and
comfort.
■ Few points to remember:
– Primary objective is retrieval of retained nucleus fragment without aspirating
vitreous.
– Retained fragments can be brought in Anterior chamber by the use of Ophthalmic
Viscoelastic Device (OVD).
– Bottle height should be lowered and vacuum reduced.
– Avoiding sculpting and rotating the nucleus. Avoid using aspiration near the PC tear

10. The Retained lens material can be manoeuvred mechanically, with the use of OVD’s
and brought to the PupillaryArea, from where it can be removed by resuming
Phacoemulsification over a temporary scaffold (Sheet’s Glide).
Sheet’s Glide

11. ■ WhenVitreous is present at the AC,
– continued phacoemulsification can exert traction on the vitreous base, increasing
the risk of retinal detachment.
– Under such circumstances, removal of the residual lens material should follow an
initial AnteriorVitrectomy.

12. ■ IF NUCLEUS IS DRIFTED OUT OF REACH INTHE POSTERIOR SEGMENT
■ No Attempt should be made to retrieve it Anterior route.
■ Even If Nucleus has dropped in theVitreous cavity, unless optimal Three Port Pars-
plana vitrectomy is immediately available the Focus should be on
1. Minimizing collateral damage by safe Management of AnteriorVitreous by
adequate Bimanual AnteriorVitrectomy.
2. Cortical Clean-up
3. A stable IOL implantation, wherever possible.
4. Tight wound closure with suture and viscoelastic removal should be done.
5. Provide referral for promptVR consultation

13. ■ BIMANUALANTERIORVITRECTOMY-
– It should be performed through the two paracentesis avoiding the use of the
main incision.
– Using a Low Bottle height, High Cut rate and low Suction, the Anterior
Chamber should be cleared ofVitreous.
– TriamcinoloneAcetonide usage for visualization ensures thoroughVitrectomy
and adequateVitreous Removal and maybe helpful in postoperative
inflammation.
– The cutter is first passed through the Rent in Posterior Capsule to remove
adequate vitreous.
– This will ensure removal of all prolapsed vitreous in the Anterior Chamber and
prevent furtherVitreous Prolapse and the enlargement of PCR.

15. IOL Implantation options
■ The decision to implant IOL during primary surgery is taken by a surgeon taking into
account,
– integrity of capsular bag,
– capsular bag and capsulorhexis margin,
– location and size of PCR,
– degree of visibility permitting an accurate assessment of capsular integrity,
– size and hardness of dislocated Lens Fragment.

16. ■ Visibility too poor to assess Capsular support, Hard nuclear fragments that have
dislocated
– Postpone IOL implantation, giving time for fibrosis of the residual Capsular bag
and may permit secondary IOL implant in SULCUS.
■ Visibility is good, PCR is small- Conversion to posterior Continuous Curvilinear
Capsulorhexis is feasible.A single Piece PC IOL can be placed in the bag
.
■ PCR is large/peripheral, a PCCC is not Feasible. If visibility is good and
capsulorehexis margin is intact, after adequate AnteriorVitrectomy, a three piece PC
IOL can be implanted in the sulcus with Optic Capture through the Capsulorhexis
margin.
■ Capsular bag can be assessed and the capsular support is found to be grossly
inadequate. Implantation of an AC IOL or fixating a PC IOL to iris (Iris Claw) or
sclera(SFIOL).

17. Medical Management
■ The aim is to treat secondary complications including intraocular inflammation and glaucoma.
■ Topical Non steroidal anti-inflammatory drugs (NSAIDS) to control inflammation along with
the Cycloplegic agents
■ Topical Anti-Glaucoma medications and Oral carbonic anhydrase inhibitors may be necessary
for IOP control.

18. DEFINITIVE SURGERY
■ TIMING OFTHE DEFINITIVE SURGERY
– Depends on an individual case bases.
– DelayedVitrectomy may lead to development of Glaucoma and Corneal Oedema
– AVitreoretinal specialist’s availability to team up with a cataract surgeon is ideal.
– IfVitreoretinal Surgeon is not available , an honest communication, a good counselling,
and appropriate referral is a must.
– Vitrectomy for dislocated nuclear fragments can be delayed upto 3 weeks without
significant difference in theVisual Outcome.

19. Pre-Operative assessment
■ Following information should be included while referring the patientVitreoretinal
Surgeon
– Amount/type/hardness of retained lens Material
– Presence/absence of an IOL implant
– Assessment of Capsular Support
– Calculated IOL power

20. ■ The following factors should be assessed before a definitive Surgery
– Integrity of the cataract wound should be verified.
– Slit-Lamp Examination to assess corneal clarity, grade the degree of anterior
chamber inflammation and Intraocular Pressure
– Indirect Ophthalmoscopy, should be performed to assess nuclear fragment as well as
to exclude Peripheral Retinal tears, Retinal Detachment or Choroidal detachment.
– B-Scan Ultrasonography in cases of Media haze (corneal oedema or associated
Vitreous Haemorrhage.

21. Surgical Procedure
■ A three-port pars planaVitrectomy is the procedure of choice and standard of care.
■ Hybrid or mixed gauge vitrectomy is performed with an active 20 G port for
introduction of a Large–bore Fragmatome. A fragmatome is similar to a PHACO probe
without an infusion Sleeve.

22. ■ STEP 1: PARS PLANAVITRECTOMY
■ Key Points :
– Remove all the vitreous from Anterior Chamber/ primary cataract wound (if
present)
– Intra vitrealTriamicilone could be utilized for better visualization of vitreous.
– All the vitreous attachment to the nucleus should be removed.
– If fragmatome is being used then induction of PVD is must and vitreous base
should be trimmed to extent possible.

23. ■ STEP 2: REMOVAL OF NUCLEUS
■ It depends upon type of nucleus:
a) Soft nucleus : Most of the times it can be removed byVitrectomy cutter itself.
■ Key Points :
– Cut rate should be low near 600-800 cuts per minute with suction on the higher
side.
– Few drops of PFCL can be used as a cushion to prevent the nucleus pieces falling
directly over the macula and causing damage to it.
– Light pipe can be used to crush the nucleus against the cutter probe for easy
cutting.

24. b) Hard Nucleus:
1) Using Fragmatome/ PhacoTip without Sleeve:
■ Key Points :
– Perform adequate vitrectomy prior to use of an ultrasonic fragmatome to avoid
vitreous fibrils being sucked into the fragmatome hand piece, causing vitreous
traction. Using triamcinolone acetonide to stain the vitreous ensures easy
visualization.
– Reducing fragmentation power to only 5 -10 % facilities nuclear extraction by
continuous occlusion of the suction port and avoidance of projectile fragments.
– Using a small bubble of PFCL for protecting retina from projectile nuclear
fragments.

26. ■ 2) Delivering Nucleus via limbal route:
– Elevating it with using Active suction with the hard tip flute cannula and
bringing it to anterior chamber.
– Using a pick/MVR blade to elevate it in the anterior chamber.The major
disadvantage being it may cause damage to underlying retina.
– Using PFCL(Perfluorocarbon liquid) to float it upto pupillary plane and then
delivering the nucleus via limbal route.The major advantage being all the nuclear
fragments floats above the bubble and can be removed, it can be also utilized
with accompanying retinal detachment.The caution has to be taken as nuclear
fragments tends to slip over the meniscus to the periphery, hence meticulous
examination of periphery also help in visualization and removal of these
fragments.

27. ■ STEP 3: PERIPHERAL EXAMINATION BY INDENTATION helps us to locate any pre
existing breaks or localize any unknown breaks caused during the surgery and manage
them by barraging them with laser intra operatively thus reducing chances of post
operative retinal detachment.

29. VISUAL OUTCOME
■ AVisual Acuity of 20/40 is achieved in 60-80 % cases with dropped nucleus.