Cataract surgery

• Summary
• Indications for surgery
• Surgical techniques
• Phacoemulsification
• Postoperative care
• Complications
• References
• Author(s)

Summary

Cataract surgery is one of the most common and effective surgical procedures performed globally. It involves removal of the cataract and replacing it with an intraocular lens (IOL), with the aim of improving vision.

Indications for surgery

Surgery is indicated in any type of cataract if the symptoms from the cataract interfere with daily function. Age is not a contraindication to cataract surgery; improvements in vision often have significant benefits for older adults.

Surgical techniques

Cataract surgery is typically performed on an outpatient basis under local anaesthesia with monitored sedation. The local anaesthesia is supplied topically, by block or by sub-Tenon’s (episcleral) infusion. It is a quick surgery, with the intraocular components usually taking 10-20 minutes (by experienced surgeons).

The two techniques most commonly performed are:

• Small incision surgery (aka phacoemulsification)
• Standard extracapsular cataract extraction (ECCE)

Small incision surgery

This is the most commonly performed technique. It involves phacoemulsification of the lens (the steps of which are described below) and implantation of a synthetic intraocular lens.

Extracapsular cataract extraction (ECCE)

In ECCE, the anterior capsule and lens are removed through a large incision, but the posterior capsule is left in the eye. The surgery involves:

• Anterior capsulotomy
• Removal of lens nucleus and cortical contents: the lens nucleus is removed in one piece through the large incision; the cortex is aspirated; and the lens capsule left behind to support an IOL
• IOL placed in the eye and incision sutured

Intracapsular cataract extraction (ICCE)

Here, the whole lens including the capsule is removed.

This is rarely performed as it does not allow for capsule-supported IOL placement and requires a sutured IOL, contact lens correction or an aphakic spectacle (aphakia = absence of a lens inside the eye), which have reduced long-term safety and outcomes compared to a capsule-supported IOL.

Phacoemulsification

Phaecoemulsification is the standard method of cataract removal in developed countries and urban centres in developing countries. It involves the following steps:

1. Corneal incision: a small incision is formed in the cornea. This needs to be 3mm wide for phacoemulsification; 10mm for extracapsular cataract; 12mm for intracapsular cataract
2. Capsulorhexis: the capsule of the lens is removed from the eye using shear and stretch forces
3. Hydrodissection: this separates the lens from the capsule. After this, the lens with the cataract can be removed
4. Removal of lens material: a common method involves using the phacoemulsification ultrasound probe to divide the lens into 4 quadrants that can then be removed
5. Viscoelastic (a viscous, gel-like substance) is used to inflate the lens
6. Insertion of intraocular lens: these are initially folded up, and they unfold in the eye after insertion

Postoperative care

• Mild pain within the first 24 hours after surgery is to be expected
• Patients can resume normal activity (e.g. reading, walking, eating, watching TV) in the evening of surgery
• The eye may be patched
• The eye is often examined 1 day post-operatively (although this is increasingly being replaced with telephone consultations for uncomplicated cases). As long as continued patching is not required, patients are usually able to resume driving
• Patients are normally seen 1 week and 1 month post-surgery to monitor for complications and proper healing
• The final glasses prescription is determined 1-3 months post-surgery. Glasses are often needed for reading and/or night driving after surgery

Complications

Whilst cataract surgery itself is a low-risk procedure, it is often performed in older adults who have medical comorbidities, which increases the risk of adverse outcomes. Furthermore, since cataract surgery is performed so frequently, even rare complications can affect large numbers of patients. Complications can be subdivided into ‘immediate’ and ‘delayed’.

Immediate complications

These may limit vision at the end of the 1-3 month recovery period.

• Endophthalmitis (〜0.1%) – caused by bacterial/fungal infection within the eye (usually from bacteria from the patient’s eyelids/conjunctiva), causing markedly reduced vision and lasting visual impairment. It is treated by injection of intravitreal antibiotics. This is an important and serious complication to remember!
• Intraocular lens malposition/dislocation
• Posterior capsule rupture with or without loss of vitreous (1-3%)
• Corneal oedema —> reduced vision, pain
• Clinically apparent cystoid macular oedema – retinal thickening and oedema involving the macula
• Toxic anterior segment syndrome (TASS) – inflammation of the anterior segment of the eye, related to non-sterility of equipment/solutions/supplies used in surgery. Typically occurs within 24 hours of surgery
• Haemorrhagic Occlusive Retinal Vasculitis (HORV) – a rare but severe condition occurring 1-21 days after intraocular vancomycin use. Hence, vancomycin is not recommended as prophylaxis against endophthalmitis in cataract surgery
• Choroidal/vitreous/anterior chamber haemorrhage (all <1%)
• Wound gape or prolapse of iris (<1%)
• Protruding/broken sutures
• Refractory uveitis

Delayed complications

• Posterior capsule opacification (19.7%) can be successfully treated with yttrium-aluminium-garnet (YAG) laser capsulotomy, hence is not universally considered a complication
• Retinal detachment – highly myopic patients are at increased risk. May require treatment with laser, cryotherapy or surgery
• Uveitis
• Open-angle glaucoma (<1%)
• Closed-angle glaucoma (<1%)
• Bullous keratopathy
• Concerns about increased risk of macular degeneration

References

1. Salmon, John F., and Jack J. Kanski. Kanski’s Clinical Ophthalmology: A Systematic Approach. Ninth Edition, Elsevier, 2020.
2. Cataract in the Adult Eye: Surgery and Diagnostic Procedures. Preferred Practice Patterns. American Academy of Ophthalmology. September 2006.
3. UpToDate. https://www.uptodate.com/contents/cataract-in-adults?source=history_widget. Accessed 2 Sept. 2022.
4. Weber, Adam C., et al. ‘A Case of Listeria Monocytogenes Endophthalmitis with Recurrent Inflammation and Novel Management’. Journal of Ophthalmic Inflammation and Infection, vol. 5, no. 1, Oct. 2015, p. 28. BioMed Central, https://doi.org/10.1186/s12348-015-0058-8.
5. Lam, Chee Kiang, et al. ‘Virtual Phacoemulsification Surgical Simulation Using Visual Guidance and Performance Parameters as a Feasible Proficiency Assessment Tool’. BMC Ophthalmology, vol. 16, no. 1, June 2016, p. 88. BioMed Central, https://doi.org/10.1186/s12886-016-0269-2.

Author(s)

Jessica Mendall

Jessica is a final year medical student studying in London. She previously studied preclinical medicine in Oxford, intercalating in Systems Neuroscience and Molecular Pathology. She is particularly interested in Ophthalmology, medical education and clinical research.

Published: 23/8/22

Last updated: 29/1/25