Anaesthesia for Cataract Surgery: Changes, Considerations and Current practice

Ruqaiyah Behranwala

The primary goals of anaesthesia for cataract surgery are to provide adequate analgesia, minimise patient anxiety and movement, and facilitate rapid postoperative recovery (1). Although general anaesthesia was historically the standard approach, it is now rarely used and is reserved for selected patients, including children, individuals with cognitive impairment, severe anxiety or claustrophobia and those with significant head tremor (2). Advances in phacoemulsification, foldable intraocular lenses and microincision techniques have driven a shift towards regional and topical anaesthetic approaches. Consequently, most cataract procedures are now performed as day-case surgeries under local anaesthesia (3).

Types of Local anaesthesia

Topical and Intracameral

Topical anaesthesia is now the most commonly used anaesthetic technique for routine cataract surgery. It involves application of anaesthetic drops or gels to the ocular surface, producing analgesia of the cornea, conjunctiva, and anterior sclera. Common agents include proxymetacaine hydrochloride, tetracaine, and lidocaine gel (4). Advantages include rapid postoperative recovery, avoidance of needle related complications and early visual rehabilitation. Lack of akinesia requires good patient cooperation and surgical experience (5). Topical anaesthesia is often supplemented with intracameral anaesthetic, typically preservative-free 1% lidocaine, instilled into the anterior chamber to provide additional analgesia to the iris and ciliary body (6).

Sub-tenon block

Sub-Tenon’s anaesthesia involves instillation of local anaesthetic into the sub-Tenon’s space using a blunt cannula. The sub-Tenon’s space is a potential space between Tenon’s capsule and the sclera, allowing circumferential spread of anaesthetic around the globe. It provides effective analgesia and moderate akinesia with a low risk of serious complications. It is particularly useful in patients who experience discomfort or excessive eye movement during surgery, as well as in those with high myopia, in whom needle-based blocks carry a higher risk of globe perforation. Minor complications include conjunctival chemosis and subconjunctival haemorrhage, while absolute contraindications are active ocular infection or prior scleral buckle surgery (7).

Retrobulbar block

Retrobulbar anaesthesia involves injection of local anaesthetic into the intraconal space, which is enclosed by the four rectus muscles and their connecting fascia, extending from the annulus of Zinn to the posterior globe. This provides rapid-onset dense analgesia and akinesia by blocking cranial nerves III and VI. Historically popular for its reliable akinesia, retrobulbar anaesthesia has declined due to the risk of serious complications, including retrobulbar haemorrhage, globe perforation, optic nerve injury, and brainstem anaesthesia. It remains indicated for anxious or uncooperative patients or when extensive intraocular manipulation is anticipated. Relative contraindications include long axial length, posterior staphyloma, and anticoagulation therapy (8).

Peribulbar block

Peribulbar anaesthesia involves injection of local anaesthetic into the extraconal space either through the skin or conjunctiva. The anaesthetic diffuses into the intraconal space, providing analgesia and variable akinesia. It is widely used for longer or more complex cataract surgeries, particularly when retrobulbar block is considered higher risk. Advantages include improved safety compared with retrobulbar block, with lower risk of globe perforation or optic nerve injury, while still providing effective analgesia. Limitations include slower onset, need for larger volumes, occasional incomplete akinesia and transient increases in intraocular pressure. Indications mirror those of retrobulbar block and include patients with long axial length, posterior staphyloma, scleral buckle, or orbital implants (9).

Conclusion

Anaesthesia for cataract surgery has evolved with advances in surgical techniques and patient expectations. The choice of anaesthesia for cataract surgery should be tailored to the individual patient, considering ocular anatomy, comorbidities, surgical complexity and patient cooperation. Topical, sub-Tenon’s, retrobulbar, and peribulbar techniques each offer distinct advantages and limitations and understanding their efficacy and safety is key to optimising patient comfort and postoperative recovery.

References

  1. Hamilton RC. Anesthesia for cataract surgery: current concepts. Curr Opin Ophthalmol. 2000;11(1):10–14.
  2. Nanji KC, Roberto SA, Morley MG, Bayes J. Preventing adverse events in cataract surgery: recommendations from a Massachusetts expert panel. Anesth Analg. 2018;126:1537–44.
  3. Wong DH. Regional anaesthesia for intraocular surgery. Can J Anaesth. 1993;40(7):635–57.
  4. Bardocci A, Lofoco G, Perdicaro S, Ciucci F, Manna L. Lidocaine 2% gel versus lidocaine 4% unpreserved drops for topical anesthesia in cataract surgery: a randomized controlled trial. Ophthalmology. 2003;110(1):144–9. doi:10.1016/S0161-6420(02)01562-2.
  5. Grabow HB. Topical anaesthesia for cataract surgery. Eur J Implant Refract Surg. 1993;5(1):20–4. doi:10.1016/S0955-3681(13)80056-1. Available from: https://www.sciencedirect.com/science/article/pii/S0955368113800561
  6. Crandall AS, Zabriskie NA, Patel BCK, Burns TA, Mamalis N, Malmquist-Carter LA, Yee R. A comparison of patient comfort during cataract surgery with topical anesthesia versus topical anesthesia and intracameral lidocaine. Ophthalmology. 1999;106(1):60–6.
  7. Roman SJ, Chong Sit DA, Boureau CM, et al. Sub-Tenon’s anaesthesia: an efficient and safe technique. Br J Ophthalmol.1997;81:673–6.
  8. Yanoff M, Duker JS. Clinical Ophthalmology. 3rd ed. Philadelphia: Elsevier; 2009. p. 442.
  9. Yanoff M, Duker JS. Clinical Ophthalmology. 3rd ed. Philadelphia: Elsevier; 2009. p. 443.

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