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Surgical technique

TL;DR — Three lens-removal techniques are in current use worldwide: phacoemulsification, manual small-incision cataract surgery (MSICS) and, decreasingly, extracapsular cataract extraction (ECCE). Phacoemulsification beats ECCE clearly — uncorrected acuity 6/12 or better at three months RR 1.81 (95% CI 1.36–2.41) and fewer eyes worse than 6/9–6/18 (RR 0.33, 0.20–0.55) (de Silva 2014, PMID 24474622). MSICS versus phacoemulsification is a near-tie on best-corrected acuity (pooled RR 0.99, 95% CI 0.98–1.01 across 7 studies and 1,223 participants) with a small uncorrected-acuity advantage to phaco (RR 0.90, 0.84–0.96) and phaco costing more than four times as much in the one trial reporting cost (Riaz 2013, PMID 24114262). Femtosecond-laser assistance has been tested more thoroughly than almost any device in ophthalmology and has not changed patient-relevant outcomes: FACT found a 3-month unaided-acuity difference of −0.01 logMAR (95% CI −0.05 to 0.03) (Day 2020, PMID 32386810), FEMCAT found composite success 41.1% vs 43.6% (adjusted OR 0.85, 0.64–1.12, p = 0.250) with €10,703 saved per additional success using conventional phaco (Schweitzer 2020, PMID 31954466), and a 42-RCT Cochrane review found low-certainty evidence of slightly fewer posterior capsule tears (Peto OR 0.50, 0.25–1.00) and a clinically unimportant 1-letter acuity advantage (Narayan 2023, PMID 37369549). The choice of technique is therefore mostly a question of setting, cost and surgeon skill, not of achievable vision.

Phacoemulsification

The standard modern operation: a 2–3 mm clear-corneal or limbal incision, continuous curvilinear capsulorhexis, hydrodissection, ultrasonic fragmentation and aspiration of the nucleus, cortical clean-up, and in-the-bag implantation of a foldable posterior-chamber IOL. It is the most common incisional operation in most high-income countries and >3.5 million are performed annually in the US alone (Chen 2025, PMID 40227658).

Technique choices with documented consequences:

  • Incision type. In the ESCRS randomised prophylaxis trial, clear-corneal incisions carried a 5.88-fold higher endophthalmitis risk than scleral tunnels (95% CI 1.34–25.9) (ESCRS Endophthalmitis Study Group 2007, PMID 17531690).
  • Nuclear disassembly. Chopping is preferred in high myopia to minimise zonular stress and reduce posterior capsule rupture (Elhusseiny 2023, PMID 36473016), and versatility across disassembly techniques with capsular support devices is recommended in pseudoexfoliation (Crandall 2018, PMID 29965904).
  • Capsulorhexis size and IOL overlap. Incomplete capsulorhexis–IOL overlap raised early PCO risk (180–360° overlap OR 2.058; <180° OR 5.403, both P < 0.001) in 1,039 eyes (Gu 2022, PMID 34727350). A 5.5 mm rhexis is recommended in exfoliation syndrome, with cortical clean-up by a tangential approach and removal of residual lens epithelial cells to reduce capsular contraction (PMID 29965904).
  • Anterior capsular polishing is recommended in myopic eyes to reduce postoperative capsular contraction syndrome (PMID 36473016).

Manual small-incision cataract surgery

MSICS uses a sutureless self-sealing scleral tunnel through which the nucleus is expressed or viscoexpressed intact, followed by IOL implantation. It requires no phacoemulsification machine or consumables and tolerates dense and mature cataracts that would demand high phaco energy.

Comparison Result Evidence Source
BCVA 6/18 or better at 6–8 weeks Pooled RR 0.99 (95% CI 0.98–1.01) — no difference 7 studies, 1,223 participants Riaz 2013, PMID 24114262
UCVA 6/18 or better at 6–8 weeks Pooled RR 0.90 (0.84–0.96) favouring phaco 3 studies, 767 participants PMID 24114262
BCVA <6/60 11 events in 1,223 participants; Peto OR 2.48 (0.74–8.28) — uncertain 7 studies PMID 24114262
Complications Too few events to detect a difference 8 trials, 1,708 participants, India/Nepal/South Africa PMID 24114262
Cost Phacoemulsification more than four times the cost of MSICS in the one trial reporting it 1 trial PMID 24114262
Endothelial cell loss at 6 weeks Phaco 543.4 vs MSICS 505.9 cells/mm² (manual count, P = 0.44); 474.2 vs 456.1 automated (P = 0.98) RCT, 200 patients Gogate 2010, PMID 20152605
CDVA better than 6/18 at 6 weeks 98.5% (phaco) vs 97.3% (MSICS) same PMID 20152605
Meta-analysis of 6 RCTs, 1,315 eyes No significant differences in BCVA 6/9 or better (P = 0.69), BCVA <6/18 (P = 0.68), endothelial cell loss (P = 0.45) or complications (P = 0.44 intraoperative, P = 0.87 postoperative) Zhang 2013, PMID 22958062

The practical consensus is unchanged from the older Cochrane synthesis: MSICS provides early visual rehabilitation and comparable visual outcome to phacoemulsification, has better outcomes than ECCE, and can be used in any clinic currently performing ECCE with IOL (Riaz 2006, PMID 17054134). Contemporary reviews position MSICS as the cost-effective and scalable technique for low- and middle-income countries, with simulator-based training improving early proficiency and complication rates and patient-reported satisfaction comparable to phacoemulsification given a proficient surgeon; the named research gaps are skill transferability, long-term outcomes and sex disparities in access (Winterton 2026, PMID 41175388; Bernhisel 2020, PMID 31770166).

Extracapsular cataract extraction

ECCE removes the nucleus through a large sutured limbal incision. It survives where phaco and MSICS are unavailable — in Palestine in 2015, 67% of government-centre cataract operations were still ECCE despite phacoemulsification being 73.4% of the national total (Maswadi 2022, PMID 34121602).

Outcome Phaco vs ECCE Evidence Source
UCVA ≥6/12 at 3 months RR 1.81 (95% CI 1.36–2.41) 2 studies, 492 participants de Silva 2014, PMID 24474622
UCVA ≥6/12 at 1 year RR 1.99 (1.45–2.73) 1 study, 439 participants PMID 24474622
BCVA ≥6/12 at 3 months RR 1.12 (1.03–1.22) 4 studies, 645 participants PMID 24474622
BCVA worse than 6/9–6/18 at 3 months RR 0.33 (0.20–0.55) favouring phaco 3 studies, 604 participants PMID 24474622
Posterior capsule rupture Peto OR 0.56 (0.26–1.22) — commoner with ECCE but uncertain 3 studies, 688 participants PMID 24474622
Iris prolapse, cystoid macular oedema, PCO All higher with ECCE 11 trials, 1,228 participants PMID 24474622

Femtosecond-laser-assisted cataract surgery

FLACS automates the corneal incisions, capsulotomy and lens fragmentation. The randomised evidence is unusually complete and unusually consistent.

Trial / review Design Primary result
FACT (Day 2020, PMID 32386810; Day 2021, PMID 33511963) 785 patients, 3 NHS hospitals, outcome-masked non-inferiority, margin 0.1 logMAR 3-month unaided acuity difference −0.01 logMAR (95% CI −0.05 to 0.03); CDVA difference −0.01 (−0.05 to 0.02); 71% of both arms within ±0.5 D, 93% vs 92% within ±1.0 D; 2 posterior capsule tears in PCS, none in FLACS
FEMCAT (Schweitzer 2020, PMID 31954466) 907 patients (1,476 eyes), 5 French university hospitals, participant-masked superiority with sham laser Composite success 41.1% vs 43.6% (adjusted OR 0.85, 95% CI 0.64–1.12, p = 0.250); ICER €10,703 saved per additional success with conventional phaco
FEMCAT cost-utility (Bénard 2023, PMID 37200037) Preplanned 12-month cost-utility FLACS not cost-effective over the evaluated horizon
Cochrane (Narayan 2023, PMID 37369549) 42 RCTs, 7,298 eyes, 5,831 participants Anterior capsular tears Peto OR 0.83 (0.40–1.72), low certainty; posterior capsular tears Peto OR 0.50 (0.25–1.00), low certainty, ≈4 fewer per 1,000; CDVA at ≥6 months MD −0.01 logMAR (−0.02 to 0.00), ≈1 letter, moderate certainty and not clinically important. 16 studies reported financial links to the laser manufacturer; 13 paired-eye studies analysed ignoring pairing
Earlier Cochrane (Day 2016, PMID 27387849) Same question, fewer trials Same direction, less precision
Meta-analysis (Lee 2025, PMID 40731148) 46 RCTs, 8,871 eyes, with trial sequential analysis Better CDVA at 1 week (P = 0.011), no difference beyond 1 week, no difference in uncorrected acuity, spherical equivalent, surgically induced astigmatism, or overall complications (P = 0.999); no clear cost-effectiveness advantage

Two methodological points from the Cochrane review deserve to be carried forward: more than a third of the included trials reported financial links with the laser manufacturer, and the within-person paired-eye studies were analysed as though the eyes were independent, which inflates apparent precision (PMID 37369549).

Where FLACS may still matter is the difficult case rather than the routine one. Perspective reviews argue advantages in hard nuclei, white cataracts, shallow anterior chambers and posterior polar cataracts, and note that the reproducible round capsulotomy gains importance with toric, multifocal and EDOF lenses where optic centration and effective lens position are critical (Chen 2026, PMID 41679368; Levitz 2021, PMID 33833494). There is level-1 evidence that posterior capsular rupture rate is lower with modern FLACS software, while the promised reduction in ultrasound energy has not been consistently demonstrated (PMID 33833494). Intra-individual comparison in the same patients showed less pupil narrowing with low-energy FLACS in grade ≤3 cataracts (0.08 ± 0.22 mm², P = 0.034) but not in grade >3 (P = 0.849), and significantly different cumulative dissipated energy between techniques (P < 0.001) (Salgado 2023, PMID 37551374). A separate femtosecond platform designed for photoemulsification achieved "zero-phaco" removal in 29 of 33 eyes (88%) in a contralateral-eye comparison (de Saint Jean 2023, PMID 37138745).

Difficult eyes

Setting Technique implications Source
High myopia (AL >26 mm) Chopping to reduce zonular stress; anterior capsular polishing against capsular contraction syndrome; higher postoperative IOP spikes and refractive surprises; only 63% achieve ≥20/40 Elhusseiny 2023, PMID 36473016
Nanophthalmos (AL ≤20.5 mm) 14 eyes in 22,847 operations (0.06%); 79% within target refraction, 21% with ≥1 D myopic shift Lai 2024, PMID 39407912
Pseudoexfoliation 9.84% of 315 consecutive eyes required scleral IOL fixation or capsular tension ring; risk stratified by mydriasis <6.30 mm, ACD <2.074 mm, lens decentration >0.260 mm Hayashi 2024, PMID 38290806; PMID 29965904
Diabetes Higher intra- and postoperative complication rates; enhanced preoperative evaluation and timing considerations Go 2021, PMID 34967932
Previous vitrectomy Higher dropped-nucleus risk; worse acuity and prediction error Lundström 2020, PMID 32126043; Lundström 2020, PMID 32649433

Risk stratification models exist but are immature: of 4,192 articles screened, eight described preoperative models grouping patients into risk categories, mostly for attending surgeons and mostly predicting zonular complications and posterior capsule rupture; the commonest predictors were poor patient positioning, advanced age, small pupils and pseudoexfoliation, and the shared methodological limitations were absent multivariable modelling, non-standardised outcomes and no external validation (Kang 2025, PMID 39900805).

Learning curve and training

Complication rate in resident-performed surgery falls by about 50% after the first 40 cases and then plateaus over the next 20; preoperative risk factors include mature cataract and abnormal zonular function (Ament 2011, PMID 21107259). A systematic review of 15 studies identified patient-related risk factors (older age, hypertension, prior vitrectomy, zonular pathology, pseudoexfoliation, poor preoperative acuity, small pupils, certain cataract types), surgeon-related factors (postgraduate year, handedness) and process factors (absence of supervision, long phacoemulsification time, high phaco power and torsion) (Kang 2024, PMID 38648911). Surgeon volume and adverse-event rates have been debated in the editorial literature (Hatch 2008, PMID 18982026).

Virtual-reality simulation is widely adopted but weakly evidenced. Six RCTs with 151 trainees were identified; all evidence was very low certainty, no meta-analysis was possible, and results were inconsistent — VR versus no supplementary training gave shorter operating times in one 12-participant study (MD −17 minutes, 95% CI −21.62 to −12.38) and fewer intraoperative complications in another (P < 0.001), while comparisons with wet-laboratory training conflicted; two of six studies were industry-funded (Lin 2021, PMID 34931701). The surgeon-experience finding in the ESCRS trial — that more experienced surgeons were more likely to be associated with endophthalmitis cases — is a reminder that case-mix confounds all surgeon-level comparisons (PMID 17531690).

Setting and cost

The technique decision in a resource-constrained system is a throughput and cost decision. Phacoemulsification cost more than four times MSICS in the one trial reporting it (PMID 24114262), and phacoemulsification surgical costs exceeded ECCE in the ECCE comparison (PMID 24474622). The older Cochrane conclusion — that phacoemulsification gives the best visual outcomes but will be accessible in poorer countries only if the cost of the machine and foldable IOLs falls — still frames the global picture (PMID 17054134). Future-of-surgery reviews add sustainability and carbon cost to the same calculation (O'Brart 2025, PMID 40082703).

Open questions

  • Does FLACS help in the cases where it is now advocated? Routine-case equivalence is established across 42 RCTs (PMID 37369549) and 46 RCTs (PMID 40731148); the claimed advantages in hard nuclei, white cataracts, shallow chambers and posterior polar cataracts (PMID 41679368) rest on perspective and case-series evidence, with no randomised trial restricted to those indications identified in this session's searches.
  • Does the industry-funding and paired-eye-analysis problem change the FLACS conclusion? 16 of 42 trials reported manufacturer links and 13 paired-eye trials ignored pairing (PMID 37369549); no re-analysis correcting for pairing has been published in this evidence set.
  • Is MSICS non-inferior on long-term endpoints? Equivalence is demonstrated at 6–8 weeks (PMID 24114262; PMID 22958062) but the Cochrane authors specifically call for developing-region research on cost, PCO and endothelial cell damage over longer follow-up (PMID 17054134), which had not appeared in the searches behind this page.
  • What does simulator training actually buy? All six randomised trials were very low certainty with inconsistent results and 151 participants in total (PMID 34931701), yet VR training is standard in most US programmes.
  • Can a validated risk-stratification model be built? Eight existing models share the same defects — no multivariable modelling, non-standardised outcomes, no external validation (PMID 39900805) — and none has been prospectively tested for improving case allocation or outcomes.

References

  1. de Silva SR, Riaz Y, Evans JR. Phacoemulsification with posterior chamber intraocular lens versus extracapsular cataract extraction (ECCE) with posterior chamber intraocular lens for age-related cataract. The Cochrane database of systematic reviews. 2014;2014:CD008812. PMID 24474622
  2. Riaz Y, de Silva SR, Evans JR. Manual small incision cataract surgery (MSICS) with posterior chamber intraocular lens versus phacoemulsification with posterior chamber intraocular lens for age-related cataract. The Cochrane database of systematic reviews. 2013;2013:CD008813. PMID 24114262
  3. Day AC, Burr JM, Bennett K, et al. Femtosecond Laser-Assisted Cataract Surgery Versus Phacoemulsification Cataract Surgery (FACT): A Randomized Noninferiority Trial. Ophthalmology. 2020;127:1012-1019. PMID 32386810
  4. Schweitzer C, Brezin A, Cochener B, et al. Femtosecond laser-assisted versus phacoemulsification cataract surgery (FEMCAT): a multicentre participant-masked randomised superiority and cost-effectiveness trial. Lancet (London, England). 2020;395:212-224. PMID 31954466
  5. Narayan A, Evans JR, O'Brart D, et al. Laser-assisted cataract surgery versus standard ultrasound phacoemulsification cataract surgery. The Cochrane database of systematic reviews. 2023;6:CD010735. PMID 37369549
  6. Chen SP, Woreta F, Chang DF. Cataracts: A Review. JAMA. 2025;333:2093-2103. PMID 40227658
  7. Endophthalmitis Study Group, European Society of Cataract & Refractive Surgeons. Prophylaxis of postoperative endophthalmitis following cataract surgery: results of the ESCRS multicenter study and identification of risk factors. Journal of cataract and refractive surgery. 2007;33:978-88. PMID 17531690
  8. Elhusseiny AM, Salim S. Cataract surgery in myopic eyes. Current opinion in ophthalmology. 2023;34:64-70. PMID 36473016
  9. Crandall AS. Exfoliation Syndrome and Cataract Surgery. Journal of glaucoma. 2018;27 Suppl 1:S102-S104. PMID 29965904
  10. Gu X, Chen X, Jin G, et al. Early-Onset Posterior Capsule Opacification: Incidence, Severity, and Risk Factors. Ophthalmology and therapy. 2022;11:113-123. PMID 34727350
  11. Gogate P, Ambardekar P, Kulkarni S, et al. Comparison of endothelial cell loss after cataract surgery: phacoemulsification versus manual small-incision cataract surgery: six-week results of a randomized control trial. Journal of cataract and refractive surgery. 2010;36:247-53. PMID 20152605
  12. Zhang JY, Feng YF, Cai JQ. Phacoemulsification versus manual small-incision cataract surgery for age-related cataract: meta-analysis of randomized controlled trials. Clinical & experimental ophthalmology. 2013;41:379-86. PMID 22958062
  13. Riaz Y, Mehta JS, Wormald R, et al. Surgical interventions for age-related cataract. The Cochrane database of systematic reviews. 2006;2006:CD001323. PMID 17054134
  14. Winterton C, Mai A, Pettey J. Manual small incision cataract surgery. Current opinion in ophthalmology. 2026;37:31-35. PMID 41175388
  15. Bernhisel A, Pettey J. Manual small incision cataract surgery. Current opinion in ophthalmology. 2020;31:74-79. PMID 31770166
  16. Maswadi R, Bascaran C, Clare G, et al. Cataract Surgical Services in Palestine. Ophthalmic epidemiology. 2022;29:223-231. PMID 34121602
  17. Day AC, Burr JM, Bennett K, et al. Femtosecond laser-assisted cataract surgery compared with phacoemulsification: the FACT non-inferiority RCT. Health technology assessment (Winchester, England). 2021;25:1-68. PMID 33511963
  18. Bénard A, Sitta R, Brezin AP, et al. Cost Utility and Value of Information Analysis of Femtosecond Laser-Assisted Cataract Surgery. JAMA ophthalmology. 2023;141:625-629. PMID 37200037
  19. Day AC, Gore DM, Bunce C, et al. Laser-assisted cataract surgery versus standard ultrasound phacoemulsification cataract surgery. The Cochrane database of systematic reviews. 2016;7:CD010735. PMID 27387849
  20. Lee SH, Chiu YC, Tsai PC, et al. Femtosecond laser-assisted cataract surgery versus conventional phacoemulsification cataract surgery: a meta-analysis of randomized controlled trials. Scientific reports. 2025;15:27569. PMID 40731148
  21. Chen X, Zhong Y, Wang K, et al. Femtosecond Laser-Assisted Cataract Surgery: Precision, Practice, and the Path to Personalization. American journal of ophthalmology. 2026;285:213-217. PMID 41679368
  22. Levitz LM, Dick HB, Scott W, et al. The Latest Evidence with Regards to Femtosecond Laser-Assisted Cataract Surgery and Its Use Post 2020. Clinical ophthalmology (Auckland, N.Z.). 2021;15:1357-1363. PMID 33833494
  23. Salgado R, Torres P, Marinho A, et al. Cataract Grade and Pupil: Comparison Between Conventional Phacoemulsification and Low-Energy Femtosecond Laser Assisted Cataract Surgery. Clinical ophthalmology (Auckland, N.Z.). 2023;17:2193-2200. PMID 37551374
  24. de Saint Jean A, Dufournel D, Stodulka P, et al. Comparison of ultrasound phacoemulsification and FemtoMatrix® PhotoEmulsification® cataract surgery. Frontiers in medicine. 2023;10:1157486. PMID 37138745
  25. Lai THT, Tse JYT, Chan JWT, et al. Visual and Refractive Outcomes after Phacoemulsification Cataract Surgery in Nanophthalmic Eyes. Journal of clinical medicine. 2024;13. PMID 39407912
  26. Hayashi K, Yoshida M, Manabe SI, et al. High-risk factors for zonular complications during cataract surgery in eyes with pseudoexfoliation syndrome. The British journal of ophthalmology. 2024;108:1193-1199. PMID 38290806
  27. Go JA, Mamalis CA, Khandelwal SS. Cataract Surgery Considerations for Diabetic Patients. Current diabetes reports. 2021;21:67. PMID 34967932
  28. Lundström M, Dickman M, Henry Y, et al. Risk factors for dropped nucleus in cataract surgery as reflected by the European Registry of Quality Outcomes for Cataract and Refractive Surgery. Journal of cataract and refractive surgery. 2020;46:287-292. PMID 32126043
  29. Lundström M, Dickman M, Henry Y, et al. Cataract surgery of eyes with previous vitrectomy: risks and benefits as reflected in the European Registry of Quality Outcomes for Cataract and Refractive Surgery. Journal of cataract and refractive surgery. 2020;46:1402-1407. PMID 32649433
  30. Kang C, Zhu AS, Waldman O, et al. Cataract surgery risk stratification models: a systematic review. Graefe's archive for clinical and experimental ophthalmology = Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie. 2025;263:1229-1238. PMID 39900805
  31. Ament CS, Henderson BA. Optimizing resident education in cataract surgery. Current opinion in ophthalmology. 2011;22:64-7. PMID 21107259
  32. Kang C, Lee MJ, Chomsky A, et al. Risk factors for complications in resident-performed cataract surgery: A systematic review. Survey of ophthalmology. 2024;69:638-645. PMID 38648911
  33. Hatch W, Singer S, Hooper P. Surgeon volumes and adverse event rates in cataract surgery. Canadian journal of ophthalmology. Journal canadien d'ophtalmologie. 2008;43:524-7. PMID 18982026
  34. Lin JC, Yu Z, Scott IU, et al. Virtual reality training for cataract surgery operating performance in ophthalmology trainees. The Cochrane database of systematic reviews. 2021;12:CD014953. PMID 34931701
  35. O'Brart D. The future of cataract surgery. Eye (London, England). 2025;39:1451-1456. PMID 40082703