Managing a nucleus drop during cataract surgery is one of the most challenging and critical situations an ophthalmic surgeon may encounter. While it’s a rare occurrence, its management demands quick thinking, precise action, and a thorough understanding of both anterior and posterior segment techniques. The goals are always to preserve vision, prevent complications, and optimize the long-term outcomes for the patient.

Different surveys in India have found the incidence rate of nucleus drop between 0.04-0.1%. ^(1,2) Dropped nucleus and cortical remnants occur most commonly in phacoemulsification, than other techniques of cataract surgery. ⁽³⁾

Certain conditions associated with posterior capsular or zonular weakness have a higher risk of nucleus drop in cataract surgery. These include the following ⁽⁴⁾:

• Pseudoexfoliation syndrome
• Advanced or intumescent cataract
• Traumatic cataract
• Previous intraocular surgeries like vitrectomy or glaucoma procedures
• Difficult situations like shallow AC, small pupil or iris transillumination defects
• Advanced age
• Chronic uveitis

Here’s a guide with the do’s and don’ts of managing a nucleus drop, to help you navigate the situation with confidence.

The Do’s: Navigating the Crisis with Care

1. Do Stay Calm and Assess the Situation Quickly: The first step in managing a nucleus drop is to remain composed. Once the nucleus drops, you must assess the situation. Understand the anatomy involved, determine if the nucleus has migrated to the posterior chamber or vitreous cavity, and evaluate any potential damage to the retina or lens capsule.
2. Do Protect the Corneal Endothelium: Protecting the corneal endothelium should be a priority. In cases where the nucleus or pieces of it are in the anterior chamber, it is crucial to minimize trauma to the cornea by using Ophthalmic Viscoelastic Devices (OVDs). If possible, avoid using excessive force while managing the situation, as this could further compromise endothelial function. ⁽⁵⁾
3. Do Call for a Vitreoretinal Back-up surgeon Promptly: A pars plana vitrectomy (PPV) is usually the main approach for managing a nucleus drop when the lens fragment has entered the vitreous cavity. This can often be performed during the same surgical session if a vitreoretinal surgeon is available, although may require anaesthesia supplementation. If the procedure cannot be completed immediately the case should be promptly referred to a retina specialist. Ensuring a water-tight wound closure is crucial. In the interim, managing inflammation and intraocular pressure (IOP) with appropriate topical and systemic treatment is essential.
4. Do Use the Right Instruments and Proper Vitrectomy Techniques for Nucleus Removal: A 23G or 25G vitrectomy system is used to safely remove the nuclear fragment. Any vitreous in the anterior chamber and near the wound should be cleared. ⁽⁶⁾ Triamcinolone can be used for better visualisation. ⁽⁷⁾ If a portion of the nucleus is too large or dense for safe extraction, divide it into smaller pieces with the vitrectomy probe and the light pipe. ⁽⁸⁾ The cut rate can be kept around 600-800 cpm, with higher suction rate (300-400 mm Hg). Fragmatome, that uses ultrasonic energy for fragmentation, can be used for hard nuclei. In such cases it is of utmost importance to clear all the vitreous around the nuclear fragments diligently. ⁽⁹⁾ Perfluorocarbon liquids (PFCL) can be used to both lift up the nucleus, and protect the retina.
5. Do Inform the Patient and Offer Clear Postoperative Guidance: Be transparent with the patient and their family about the situation. Discuss the potential outcomes, including the risk of retinal detachment or vision loss. Outline the post-operative care plan, which may include a course of antibiotics and steroids, close monitoring, additional surgical procedures, and possibly longer recovery times.

The Don’ts: What to Avoid in a Nucleus Drop Incident

1. Don’t Attempt to Extract the Nucleus with Fishing Manoeuvres: A common mistake is attempting to extract the nucleus with anterior segment techniques. In cases where the nucleus fragment is in the anterior hyaloid face, posterior assisted levitation (PAL) can be done. ⁽⁵⁾ In this technique, the fragments are approached from a pars plana route and a dispersive viscoelastic is injected behind them. The fragments are then maneuvered into the anterior chamber with the tip of injecting cannula. If the nucleus has entered the posterior segment or vitreous cavity, performing a vitrectomy is essential for both safe removal and proper management.
2. Don’t Neglect the Retina: It's easy to focus entirely on the lens material during a nucleus drop, but never neglect a thorough retinal examination. Inadequate vitrectomy may leave debris or fragments behind, increasing the risk of secondary complications such as retinal detachment or inflammation. Retinal tears or detachment may go unnoticed if not evaluated promptly. Avoid assuming that the retina is unaffected by the lens drop—always assess it directly with good pupillary dilation. ⁽¹⁰⁾
3. Don’t Choose Aphakia: The correct IOL can be chosen depending on the capsular support. For sulcus fixation, a 3 piece or PMMA lens is preferred over a single piece IOL. In case of absence of adequate support, it is better to plan for a scleral-fixated, iris claw or looped anterior chamber IOL, in the same or separate sitting.
4. Don’t Ignore the Risk of Postoperative Uveitis or Endophthalmitis: An intraocular foreign body, such as a nuclear fragment, can increase the risk of vitritis/ endophthalmitis. Prophylactic antibiotic therapy should be administered, and the wound should be sealed carefully to prevent infection. Always double-check your incision sites and ensure that they are watertight before finishing the procedure.
5. Don’t Forget About Long-Term Follow-Up: After managing a nucleus drop, the patient's recovery needs ongoing attention. Frequent follow-ups are necessary to monitor for potential complications like cystoid macular edema (CME), retinal tear or detachment. ⁽¹¹⁾ Keeping a vigilant eye on postoperative healing ensures that any complications can be managed early for the best possible visual outcomes.

Conclusion: Mastering Nucleus Drop Management

Managing a nucleus drop is a delicate balance of precision, patience, and experience. By following these do’s and don’ts, you can optimize both the surgical outcome and the patient’s long-term vision. Remember that handling these complications with the right technique, tools and a calm demeanour is the key to ensuring a successful result.

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