What are the advantages of phacoemulsification over traditional cataract surgery?

Advantages of Phacoemulsification Over Traditional Cataract Surgery

Phacoemulsification is superior to traditional extracapsular cataract extraction (ECCE) and should be the preferred technique when available, as it produces better uncorrected visual acuity, fewer surgical complications, and less induced astigmatism. 1

Visual Outcomes

Uncorrected Visual Acuity:

• Phacoemulsification produces significantly better uncorrected distance visual acuity (UDVA) compared to manual extracapsular cataract extraction (ECCE), allowing more patients to function without glasses immediately after surgery 1
• Meta-analysis demonstrates that a greater proportion of patients achieve final uncorrected visual acuity ≥6/9 with phacoemulsification compared to manual small-incision cataract surgery (MSICS) 2
• At 6 weeks postoperatively, 81% of phacoemulsification patients achieved presenting visual acuity ≥6/18 compared to 71% with MSICS 3

Best-Corrected Visual Acuity:

• Final best-corrected visual acuity outcomes are equivalent between techniques, with approximately 98% of patients achieving ≥6/18 vision with both phacoemulsification and MSICS 3, 2
• This indicates that while phacoemulsification provides better immediate uncorrected vision, both techniques ultimately restore excellent visual function when refractive correction is provided 3

Surgical Complications

Lower Complication Rates:

• Randomized clinical trials demonstrate that phacoemulsification has a lower rate of serious surgical complications compared to manual ECCE, specifically reduced rates of iris prolapse and posterior capsule rupture 1
• Overall intraoperative and postoperative complication rates are comparable between phacoemulsification and MSICS, though phacoemulsification shows slightly fewer posterior capsular rents in some studies 3, 2

Corneal Safety:

• Endothelial cell loss is similar between phacoemulsification and MSICS, with no significant difference in the percentage of endothelial cell count loss 2
• Central corneal thickness changes are comparable between techniques, though phacoemulsification may cause slightly more corneal edema on the first postoperative day 3

Refractive Advantages

Reduced Astigmatism:

• Phacoemulsification induces significantly less surgically-induced astigmatism (SIA) compared to both MSICS and traditional ECCE 1, 2
• Mean SIA with phacoemulsification is approximately 0.86-1.1 diopters compared to 1.16-1.2 diopters with MSICS 4, 3
• Meta-analysis confirms phacoemulsification causes substantially less astigmatism (P < 0.00001) 2

Astigmatism Management:

• The small incision used in phacoemulsification limits astigmatic changes that occur with larger incisions 1
• This enables both better astigmatism management and the implantation of specialty intraocular lenses (IOLs) that require precise refractive outcomes 1

Technical Advantages

Incision Size:

• Phacoemulsification utilizes sutureless, small-incision technique (typically 2.2-3.0mm) with foldable IOL implantation 1, 5
• Smaller incisions heal faster, require fewer or no sutures, and result in more stable refractive outcomes 1

Specialty IOL Compatibility:

• The precise nature of phacoemulsification enables implantation of premium IOLs including multifocal, extended depth of focus, and toric lenses 1
• These specialty lenses require the minimal astigmatism and precise refractive outcomes that phacoemulsification provides 1

Important Caveats

Surgical Time:

• Manual MSICS is significantly faster than phacoemulsification (mean 10.8 minutes vs 13.2 minutes), which may be relevant in high-volume settings 4
• In economically disadvantaged countries or eye camps where surgical volume is high and access to phacoemulsification is limited, MSICS remains a cost-effective alternative 1, 4

Cost Considerations:

• While phacoemulsification is superior in outcomes, MSICS remains popular in resource-limited settings due to cost-effectiveness 1
• When performed well, MSICS produces excellent final visual outcomes despite slightly higher astigmatism 6

Special Populations:

• In uveitic cataract, both techniques show comparable complication rates and final corrected visual acuity, though phacoemulsification still induces less astigmatism 4
• Manual SICS may be preferred in settings with limited phacoemulsification access or when surgical volume demands faster technique 4

Clinical Bottom Line

Phacoemulsification should be the standard technique in settings where it is available, as it provides superior uncorrected visual acuity, lower complication rates, and significantly less induced astigmatism compared to traditional ECCE. 1, 2 The technique's small-incision approach enables both better refractive outcomes and the use of premium IOLs that can further enhance visual function 1. While manual small-incision techniques remain valuable in resource-limited settings and produce equivalent best-corrected visual outcomes, phacoemulsification's advantages in uncorrected vision and astigmatism control make it the preferred approach when accessible 1, 3, 2.