Cataracts and ‘The Block’: When Surgeons Demand Local

If you’re like me, you’ve spent time in the eye suite managing "MAC" cases that didn’t feel like MAC at all — an 85-year-old with dementia, claustrophobia, and Parkinson’s tremors who absolutely cannot hold still, while the surgeon wants to operate through a microscope. The cataract is "routine." The patient is anything but. On the anesthesiology oral boards, the eye suite scenario is a test of your professional backbone and your ability to recognize when sedation has become more dangerous than a different anesthetic altogether.

The examiner’s goal in these scenarios is to see if you’ll cave to social pressure — an impatient surgeon, an anxious patient — or whether you’ll hold the standard of care even when it’s uncomfortable. Holding that line is what passes the exam.

The Core Logic

Cataract surgery typically involves topical anesthesia plus IV sedation, a peri/retrobulbar block, or general anesthesia. The choice depends on patient cooperation, comorbidities, and the surgeon’s preference. The fundamental principle: the anesthetic technique must produce a still, comfortable patient who can breathe safely. Sedation that blunts cooperation but not movement — or that depresses respiration — achieves none of these goals.

The trap is incremental escalation: a little more propofol, a little more midazolam, until the patient is snoring on a stretcher with their airway unprotected and their SpO2 drifting down — all while the surgeon is halfway through the case. The consultant prevents this by defining the limits upfront and sticking to them.

How the Examiner Tests This

The standard scenario: elderly patient with moderate dementia, scheduled for cataract extraction under MAC. Mid-case the patient starts moving. The surgeon asks for "more sedation." You give more propofol. The patient’s respiratory rate drops to 6 and the SpO2 falls to 90%. The examiner watches what you do next.

Common probes: "The surgeon says the procedure will take another 15 minutes and we just need to get through it." Your answer must address patient safety first — an apneic patient in a procedure chair is not a manageable situation, and giving more sedation is not the answer. "What do you do?" Provide airway support, wake the patient, and have a frank conversation about whether to continue, convert to GA, or reschedule.

The Board Trap

The titration trap: giving progressively more sedation in response to a moving patient without reassessing the patient’s airway and respiratory status. Elderly patients have narrow therapeutic windows. The dose that stops movement also stops breathing.

The retrobulbar block trap: if you perform a retrobulbar or peribulbar block, you must know the specific complications. Retrobulbar hemorrhage can cause orbital compartment syndrome and vision loss. Brainstem anesthesia occurs when local anesthetic tracks along the optic nerve sheath into the subarachnoid space — the patient goes apneic and unconscious. Your management: support ventilation and hemodynamics until the local anesthetic redistributes. This is self-limited, but it can last 20-30 minutes and requires you to maintain the airway the entire time.

Lead-In Phrases

• "I will define the limits of sedation with the surgeon before starting the case — if the patient requires more than light sedation to remain cooperative, we should discuss converting to a general anesthetic or rescheduling."
• "My first priority is the patient’s respiratory safety, not completion of the procedure. I will not continue to escalate sedation in the setting of respiratory depression."
• "If I perform a retrobulbar block, I am prepared to manage the two most serious complications: retrobulbar hemorrhage, which requires immediate orbital decompression, and brainstem anesthesia, which requires supportive ventilation for 20-30 minutes until the block resolves."
• "If the patient cannot cooperate under light sedation and the block is inadequate, the safest path is general anesthesia with a laryngeal mask airway — not more propofol."
• "I will establish a clear communication plan with the surgeon: we have agreed on a maximum sedation depth, and if we reach that level, we pause the case and reassess."

FAQs

Is an LMA appropriate for cataract surgery under GA?

Yes — a properly seated LMA provides airway protection while avoiding the hemodynamic and IOP spikes associated with intubation and extubation. The key requirement: no active reflux risk, and the patient must be deep enough to tolerate the LMA without coughing or bucking. A cough on emergence is a significant IOP event in an open globe that’s just been sutured closed.

What’s the IOP concern with emergence?

IOP spikes during coughing, straining, and bucking can be 30-40 mmHg above baseline. In a closed, healed eye this is usually tolerable. In an eye that’s been opened and sutured, it risks wound dehiscence and vitreous extrusion. A smooth emergence — deep extubation or IV lidocaine 1-1.5 mg/kg before emergence — significantly reduces this risk.

How do I manage the anxious patient who won’t stop moving?

The conversation happens before induction, not after. I talk with the patient about what they’ll experience, reassure them they won’t see the instruments, and establish a signal (squeezing my hand) if they need to stop. Dexmedetomidine is a reasonable anxiolytic adjunct because it provides sedation without respiratory depression. If none of this is sufficient, the honest answer is to offer general anesthesia — not to sedate them into a dangerous respiratory depression.

The eye suite is a test of your leadership. Practice saying "no" to more sedation in Boards Bot — because the examiner is going to play the role of the impatient surgeon, and your answer has to come from clinical logic, not social pressure.