What is the most common anesthesia used for cataract surgery? Understanding Modern Approaches

October 7, 2025 •

5 min read

For routine cataract surgery using modern phacoemulsification, the need for deep general anesthesia has been largely replaced by more localized methods. Today, the combination of topical anesthetic eye drops and an intracameral injection of lidocaine is the most common anesthesia used for cataract surgery, providing excellent pain control with minimal risk. This approach is often supplemented with intravenous (IV) sedation to help patients relax throughout the procedure.

Quick Summary

A combination of topical anesthetic eye drops and intracameral lidocaine is the most prevalent anesthesia method for cataract surgery. This is often paired with intravenous sedation to manage anxiety. Less frequently used options include regional anesthetic blocks and general anesthesia, reserved for specific medical or patient needs. The choice depends on the patient, surgeon, and complexity of the case.

Key Points

Combined Local Anesthesia is Most Common: A combination of topical anesthetic drops and an intracameral lidocaine injection is the standard for most modern cataract surgeries.
Topical Drops Numb the Surface: Eye drops like proparacaine provide initial numbing of the eye's surface, a non-invasive and low-risk method.
Intracameral Injection Provides Deeper Numbing: An injection of preservative-free lidocaine inside the eye is used to provide deeper anesthesia for internal structures and manage discomfort from lens manipulation.
IV Sedation Reduces Anxiety: Mild IV sedation (Monitored Anesthesia Care) is frequently used to help patients relax, though they remain conscious and able to cooperate.
Regional Blocks Provide Deeper Numbness and Eye Immobility: Injected regional blocks (peribulbar, retrobulbar) are used for more complex cases or less cooperative patients, as they paralyze eye muscles.
General Anesthesia is Rare: Complete unconsciousness with general anesthesia is reserved for specific cases like children or patients who cannot remain still.
Choice Depends on Patient and Case: Factors such as patient anxiety, surgical complexity, and overall health determine the best anesthetic approach.

Topical and Intracameral Anesthesia: The Modern Standard

With advancements in surgical techniques, particularly small-incision phacoemulsification, the need for deep anesthesia has significantly decreased. The overwhelming trend, particularly in Western countries, is the use of topical anesthesia, often enhanced by an intracameral injection. This approach offers a balance of patient comfort, safety, and rapid visual recovery.

Topical Anesthesia: This involves the administration of anesthetic eye drops, such as proparacaine or tetracaine, to the surface of the eye.

The drops act on the cornea and conjunctiva, blocking nerve signals and numbing the surface.
It is a non-invasive technique that avoids the risks associated with needles.
A key aspect of topical anesthesia is that the patient's eye muscles are not paralyzed, so the patient must be able to remain still and fixate on a microscope light during the short procedure.

Intracameral Anesthesia: To supplement topical drops and reduce discomfort from internal eye manipulation, a small, diluted dose of a preservative-free local anesthetic, most commonly 1% lidocaine, is injected into the anterior chamber of the eye.

This technique provides deeper anesthesia for sensitive structures like the iris and ciliary body.
It has been shown to significantly reduce intraoperative pain during lens manipulation and intraocular lens (IOL) insertion.

The Role of Intravenous (IV) Sedation

In many modern practices, topical and intracameral anesthesia is combined with mild-to-moderate IV sedation, often called 'twilight sedation' or Monitored Anesthesia Care (MAC).

Sedative medications like midazolam (Versed) and opioids like fentanyl may be administered through an IV.
This relaxes the patient, reduces anxiety, and may cause partial amnesia, leading to a more comfortable and less stressful experience.
The patient remains conscious and is able to follow instructions but is more relaxed and less aware of the procedure.

Regional Anesthetic Blocks: Less Common but Still Used

Before the widespread use of topical and intracameral methods, regional blocks were the standard for cataract surgery. These involve injecting local anesthetic around the eye to numb it and paralyze the eye muscles (akinesia), preventing movement.

Peribulbar block: Anesthetic is injected into the orbit but outside the muscle cone. It is safer than the retrobulbar block but may provide less akinesia.
Retrobulbar block: Involves injecting anesthetic directly inside the muscle cone behind the eye. This provides deep anesthesia and complete akinesia but carries higher risks, such as retrobulbar hemorrhage or globe perforation.
Sub-Tenon's block: A blunt cannula is used to deliver anesthetic into the space between the Tenon's capsule and the eye, providing effective and safe anesthesia.

Regional blocks are now typically reserved for more complex, longer cases, or in patients unable to cooperate sufficiently for topical techniques.

General Anesthesia: A Rare Option

General anesthesia, which renders the patient completely unconscious, is rarely used for cataract surgery due to its increased risks compared to local techniques. It is reserved for specific patient populations, including:

Pediatric patients
Adults who cannot cooperate or lie still for the procedure
Individuals with severe anxiety, cognitive impairments, or involuntary eye movements (nystagmus)
Patients with an allergy to local anesthetic agents

Comparison of Anesthesia Techniques for Cataract Surgery


Feature	Topical/Intracameral Anesthesia	Regional Block (Peribulbar)	General Anesthesia
Application	Drops applied to the eye surface, plus a small internal injection.	Injection near or around the eye.	Administered via IV and mask.
Consciousness	Awake, but relaxed with IV sedation.	Awake, but relaxed with IV sedation.	Unconscious.
Eye Movement	Patient must be able to remain still and fixate on light.	Eye muscles are paralyzed, ensuring no movement.	Eye muscles are paralyzed.
Typical Use	Most routine cataract surgeries.	Complex, longer, or less cooperative cases.	Children, highly anxious, or uncooperative patients.
Onset/Recovery	Very fast onset; quick recovery.	Slower onset; longer recovery time from block effects.	Longer recovery time.
Primary Risk	Minimal; potential mild discomfort.	Low risk, but higher than topical; bruising, swelling.	Higher risk; heart/lung complications.

Factors Influencing the Choice of Anesthesia

Several factors contribute to the selection of the most appropriate anesthesia for a cataract patient:

Patient Anxiety: Many patients feel anxious about having eye surgery while awake. IV sedation is often used to manage this and provide a more comfortable experience.
Surgical Complexity: Cases involving hard, dense cataracts or other complicating factors may require a regional block to ensure complete immobility and pain control.
Surgeon and Patient Preference: A surgeon's training and comfort level with a technique, combined with patient desires, play a significant role in the choice of anesthesia.
Underlying Medical Conditions: Certain systemic conditions can influence the choice. For instance, some patients with severe lung disease may tolerate IV sedation better than general anesthesia.
Patient Cooperation: The ability of the patient to remain still and follow instructions is crucial for the success of a topical technique. For uncooperative patients, an injection block or general anesthesia is required.

The Pharmacology of Common Agents

Understanding the medications used is key to appreciating the safety and efficacy of modern cataract anesthesia.

Amide Anesthetics (e.g., Lidocaine): These are the most common local anesthetics used. Lidocaine works by blocking voltage-gated sodium channels in nerve membranes, preventing pain signal propagation. For intracameral use, preservative-free formulations are crucial to prevent ocular surface toxicity.
Ester Anesthetics (e.g., Proparacaine): These are commonly used for topical numbing. Like amides, they inhibit nerve signals but are metabolized differently. Proparacaine has a fast onset and short duration, making it ideal for the start of the procedure.
IV Sedatives (e.g., Midazolam): Midazolam is a benzodiazepine that acts on GABA receptors in the central nervous system to produce sedation, reduce anxiety, and cause amnesia.
IV Analgesics (e.g., Fentanyl): This potent opioid is often used alongside midazolam to enhance pain relief and relaxation, further contributing to patient comfort.

Conclusion

Today, the most common anesthesia used for cataract surgery is a combination of topical drops and an intracameral injection of lidocaine, often supplemented with IV sedation. This approach is favored due to its high efficacy, excellent safety profile, and faster recovery time compared to regional blocks and general anesthesia. The optimal choice of anesthesia is a patient-specific decision, balancing anxiety management, surgical needs, and patient health. While regional blocks and general anesthesia remain available for more complex or special circumstances, the shift towards less invasive, needle-free techniques for most cases has significantly improved the patient experience. The decision should be made in close consultation with the surgical team to ensure maximum comfort and safety throughout the procedure.

Visit the National Institutes of Health website for more information on the efficacy of different anesthetic techniques for cataract surgery.

Frequently Asked Questions

Yes, for most cataract surgeries, you will be awake and conscious, though typically very relaxed from mild intravenous (IV) sedation. Most patients only remember parts of the procedure, and some may even fall asleep lightly.

Commonly used topical eye drops for numbing the surface of the eye include proparacaine and tetracaine. These provide rapid, short-acting relief at the surgical site.

The intracameral injection involves a small dose of preservative-free lidocaine administered inside the eye. It supplements topical drops by numbing sensitive structures like the iris, significantly reducing discomfort during the procedure.

Topical anesthesia uses eye drops to numb the surface, requiring the patient to keep their eye still during surgery. An eye block, an injection near the eye, numbs the eye and paralyzes the eye muscles, ensuring the eye cannot move.

Local anesthesia carries very low risk, especially topical methods. Injection-based blocks have a small but higher risk of complications, such as bruising or swelling, which is why topical methods are often preferred when possible.

The numbing effects of local anesthetics typically wear off within an hour or two after the procedure. The mild sedation may cause drowsiness for several hours, so it is important to have someone drive you home.

General anesthesia is used in rare cases, such as for children, patients with certain neurological conditions, those with severe anxiety who cannot remain still, or individuals with an allergy to local anesthetics.