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Meta-Analysis
. 2014 Jan 29;2014(1):CD008812.
doi: 10.1002/14651858.CD008812.pub2.

Phacoemulsification with posterior chamber intraocular lens versus extracapsular cataract extraction (ECCE) with posterior chamber intraocular lens for age-related cataract

Samantha R de Silva  1 , Yasmin Riaz, Jennifer R Evans
Affiliations
Meta-Analysis

Phacoemulsification with posterior chamber intraocular lens versus extracapsular cataract extraction (ECCE) with posterior chamber intraocular lens for age-related cataract

Samantha R de Silva et al. Cochrane Database Syst Rev. .

Abstract

Background: Age-related cataract is one of the leading causes of blindness worldwide. Therefore, it is important to establish the most effective surgical technique for cataract surgery.

Objectives: The aim of this review is to examine the effects of two types of cataract surgery for age-related cataract: phacoemulsification and extracapsular cataract extraction (ECCE).

Search methods: We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2013, Issue 4), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to May 2013), EMBASE (January 1980 to May 2013), Latin American and Caribbean Literature on Health Sciences (LILACS) (January 1982 to May 2013), Web of Science Conference Proceedings Citation Index - Science (CPCI-S) (January 1970 to May 2013), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 13 May 2013.

Selection criteria: We included randomised controlled trials of phacoemulsification compared to ECCE for age-related cataract.

Data collection and analysis: Two authors independently selected and assessed all studies. We defined two primary outcomes: 'good functional vision' (presenting visual acuity of 6/12 or better) and 'poor visual outcome' (best corrected visual acuity of less than 6/60) at three and 12 months after surgery. We also collected data on intra and postoperative complications, and the cost of the procedures.

Main results: We included 11 trials in this review with a total of 1228 participants, ranging from age 45 to 94. The studies were generally at unclear risk of bias due to poorly reported trial methods. No study reported presenting visual acuity, so we report both uncorrected (UCVA) and best corrected visual acuity (BCVA). Studies varied in visual acuity assessment methods and time frames at which outcomes were reported. Participants in the phacoemulsification group were more likely to achieve UCVA of 6/12 or more at three months (risk ratio (RR) 1.81, 95% confidence interval (CI) 1.36 to 2.41, two studies, 492 participants) and one year (RR 1.99, 95% CI 1.45 to 2.73, one study, 439 participants). People in the phacoemulsification group were also more likely to achieve BCVA of 6/12 or more at three months (RR 1.12, 95% CI 1.03 to 1.22, four studies, 645 participants) and one year (RR 1.06, 95% CI 0.99 to 1.14, one study, 439 participants), but the difference between the two groups was smaller. No trials reported BCVA less than 6/60 but three trials reported BCVA worse than 6/9 and 6/18: there were fewer events of this outcome in the phacoemulsification group than the ECCE group at both the three-month (RR 0.33, 95% CI 0.20 to 0.55, three studies, 604 participants) and 12-month time points (RR 0.62, 95% CI 0.36 to 1.05, one study, 439 participants). Three trials reported posterior capsule rupture: this occurred more commonly in the ECCE group than the phacoemulsification group but small numbers of events mean the true effect is uncertain (Peto odds ratio (OR) 0.56, 95% CI 0.26 to 1.22, three studies, 688 participants). Iris prolapse, cystoid macular oedema and posterior capsular opacification were also higher in the ECCE group than the phacoemulsification group. Phacoemulsification surgical costs were higher than ECCE in two studies. A third study reported similar costs for phacoemulsification and ECCE up to six weeks postoperatively, but following this time point ECCE incurred additional costs due to additional visits, spectacles and laser treatment to achieve a similar outcome.

Authors' conclusions: Removing cataract by phacoemulsification may result in a better visual acuity compared to ECCE, with a lower complication rate. The review is currently underpowered to detect differences for rarer outcomes, including poor visual outcome. The lower cost of ECCE may justify its use in a patient population where high-volume surgery is a priority, however, there are a lack of data comparing phacoemulsification and ECCE in lower-income settings.

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Conflict of interest statement

None known.

Figures

1
1
Types of cataract surgery
2
2
Study flow diagram.
3
3
'Risk of bias' graph: review authors' judgements about each risk of bias item presented as percentages across all included studies.
4
4
'Risk of bias' summary: review authors' judgements about each risk of bias item for each included study.
1.1
1.1. Analysis
Comparison 1 Phacoemulsification versus ECCE, Outcome 1 Good functional vision at 3 months (uncorrected acuity).
1.2
1.2. Analysis
Comparison 1 Phacoemulsification versus ECCE, Outcome 2 Good functional vision at 12 months (uncorrected acuity).
1.3
1.3. Analysis
Comparison 1 Phacoemulsification versus ECCE, Outcome 3 Good functional vision at 3 months (best corrected acuity).
1.4
1.4. Analysis
Comparison 1 Phacoemulsification versus ECCE, Outcome 4 Good functional vision at 12 months (best corrected acuity).
1.5
1.5. Analysis
Comparison 1 Phacoemulsification versus ECCE, Outcome 5 Poor visual outcome at 3 months (best corrected acuity 6/60 or worse).
1.6
1.6. Analysis
Comparison 1 Phacoemulsification versus ECCE, Outcome 6 Poor visual outcome at 12 months (best corrected acuity 6/60 or worse).
1.7
1.7. Analysis
Comparison 1 Phacoemulsification versus ECCE, Outcome 7 Capsular rupture.
1.8
1.8. Analysis
Comparison 1 Phacoemulsification versus ECCE, Outcome 8 % corneal endothelial cell loss.
1.10
1.10. Analysis
Comparison 1 Phacoemulsification versus ECCE, Outcome 10 Posterior capsule opacification.
1.11
1.11. Analysis
Comparison 1 Phacoemulsification versus ECCE, Outcome 11 Retinal detachment.
1.12
1.12. Analysis
Comparison 1 Phacoemulsification versus ECCE, Outcome 12 Cystoid macular oedema.
1.13
1.13. Analysis
Comparison 1 Phacoemulsification versus ECCE, Outcome 13 Iris prolapse.
See this image and copyright information in PMC

Update of

References

References to studies included in this review

Chee 1999 {published data only}
    1. Chee SP, Ti SE, Sivakumar M, Tan DT. Postoperative inflammation: extracapsular cataract extraction versus phacoemulsification. Journal of Cataract and Refractive Surgery 1999;25(9):1280‐5. - PubMed
Díaz‐Valle 1998 {published data only}
    1. Díaz‐Valle D, Benítez del Castillo Sánchez JM, Castillo A, Sayagués O, Moriche M. Endothelial damage with cataract surgery techniques. Journal of Cataract and Refractive Surgery 1998;24(7):951‐5. - PubMed
George 2005 {published data only}
    1. George R, Rupauliha P, Sripriya AV, Rajesh PS, Vahan PV, Praveen S. Comparison of endothelial cell loss and surgically induced astigmatism following conventional extracapsular cataract surgery, manual small‐incision surgery and phacoemulsification. Ophthalmic Epidemiology 2005;12(5):293‐7. - PubMed
Kara‐Junior 2010 {published data only}
    1. Kara‐Junior N, Sirtoli MG, Santhiago MR, Parede TR, Espíndola RF, Carvalho Rde S. Phacoemulsification versus extracapsular extraction: governmental costs. Clinics 2010;65(4):357‐61. - PMC - PubMed
Katsimpris 2004 {published data only}
    1. Katsimpris JM, Petropoulos IK, Apostolakis K, Feretis D. Comparing phacoemulsification and extracapsular cataract extraction in eyes with pseudoexfoliation syndrome, small pupil, and phacodonesis. Klinische Monatsblätter für Augenheilkunde 2004;221(5):328‐33. - PubMed
Landau 1999 {published data only}
    1. Landau IM, Laurell CG. Ultrasound biomicroscopy examination of intraocular lens haptic position after phacoemulsification with continuous curvilinear capsulorhexis and extracapsular cataract extraction with linear capsulotomy. Acta Ophthalmologica Scandinavica 1999;77(4):394‐6. - PubMed
Laurell 1998 {published data only}
    1. Laurell CG, Zetterstrom C, Philipson B, Syren‐Nordqvist S. Randomized study of the blood‐aqueous barrier reaction after phacoemulsification and extracapsular cataract extraction. Acta Ophthalmologica Scandinavica 1998;76(5):573‐8. - PubMed
MEHOX 2004 {published data only}
    1. Bourne RR, Minassian DC, Dart JK, Rosen P, Kaushal S, Wingate N. Effect of cataract surgery on the corneal endothelium: modern phacoemulsification compared with extracapsular cataract surgery. Ophthalmology 2004;111(4):679‐85. - PubMed
    1. Minassian DC, Rosen P, Dart JKG, Reidy A, Desai P, Sidhu M. Extracapsular cataract extraction compared with small incision surgery by phacoemulsification: a randomised trial. British Journal of Ophthalmology 2001;85(7):822‐9. - PMC - PubMed
Ravalico 1997 {published data only}
    1. Ravalico G, Tognetto D, Palomba MA, Lovisato A, Baccara F. Corneal endothelial function after extracapsular cataract extraction and phacoemulsification. Journal of Cataract and Refractive Surgery 1997;23(7):1000‐5. - PubMed
Rizal 2003 {published data only}
    1. Rizal AM, Aljunid SM, Normalina M, Hanom AF, Chuah KL, Suzainah Y, et al. Cost analysis of cataract surgery with intraocular lens implantation: a single blind randomised clinical trial comparing extracapsular cataract extraction and phacoemulsification. Medical Journal of Malaysia 2003;58(3):380‐6. - PubMed
Stumpf 2006 {published data only}
    1. Stumpf S, Nosé W. Endothelial damage after planned extracapsular cataract extraction and phacoemulsification of hard cataracts. Arquivos Brasileiros de Oftalmologia 2006;69(4):491‐6. - PubMed

References to studies excluded from this review

Arriaga 2002 {published data only}
    1. Arriaga ME, Lozono J. A comparative study of visual acuity outcomes: phacoemulsification vs extracapsular cataract extraction. Investigative Ophthalmology and Visual Science 2002;43:E‐Abstract 360.
Balent 2001 {published data only}
    1. Balent LC, Narendrum K, Patel S, Kar S, Patterson DA. High volume sutureless intraocular lens surgery in a rural eye camp in India. Ophthalmic Surgery and Lasers 2001;32(6):446‐55. - PubMed
Bellucci 1995 {published data only}
    1. Bellucci R, Morselli S, Pucci V. Small pupils: An indication of phacoemulsification. European Journal of Implant and Refractive Surgery 1995;7(4):236‐9.
Bömer 1995 {published data only}
    1. Bömer TG, Lagrèze WD, Funk J. Increased intraocular pressure after cataract extraction‐‐effect of surgical technique, surgical procedure and preventive drug administration. A prospective, randomized double‐blind study. Klinische Monatsblätter für Augenheilkunde 1995;206(1):13‐9. - PubMed
Bovet 1992 {published data only}
    1. Bovet J, Stepanian E, Leuenberger PM. Phacoemulsification: technical initiation at what price?. Klinische Monatsblätter für Augenheilkunde 1992;200(5):447‐50. - PubMed
Bovet 1994 {published data only}
    1. Bovet J, Baumgartner JM. Benefits of ambulatory surgery in cataract surgery. Klinische Monatsblätter für Augenheilkunde 1994;204(5):282‐5. - PubMed
Cavallini 1996 {published data only}
    1. Cavallini GM, Lugli N, Campi L, Lazzerini A, Longanesi L. Surgically induced astigmatism after manual extracapsular cataract extraction or after phacoemulsification procedure. European Journal of Ophthalmology 1996;6(3):257‐63. - PubMed
Dam‐Johansen 1993 {published data only}
    1. Dam‐Johansen M, Olsen T. Refractive results after phacoemulsification and ECCE: A comparative study. Acta Ophthalmologica 1993;71(3):382‐7. - PubMed
Dowler 2000 {published data only}
    1. Dowler JG, Hykin PG, Hamilton AM. Phacoemulsification versus extracapsular cataract extraction in patients with diabetes. Ophthalmology 2000;107(3):457‐62. - PubMed
Egger 1994 {published data only}
    1. Egger SF, Huber‐Spitzy V, Skorpik C, Weghaupt H, Scholda C, Arocker‐Mettinger E, et al. Different techniques of extracapsular cataract extraction: Bacterial contamination during surgery. Prospective study on 230 consecutive patients. Graefe's Archive for Clinical and Experimental Ophthalmology 1994;232(5):308‐11. - PubMed
Geerling 2000 {published data only}
    1. Geerling G, Dart JK. Management and outcome of cataract surgery in ocular cicatricial pemphigoid. Graefe's Archive for Clinical and Experimental Ophthalmology 2000;238(2):112‐8. - PubMed
Grinbaum 2003 {published data only}
    1. Grinbaum A, Blumenthal M, Assia E. Comparison of intraocular pressure profiles during cataract surgery by phacoemulsification and extracapsular cataract extraction. Ophthalmic Surgery, Lasers and Imaging 2003;34(3):182‐6. - PubMed
Honda 1995 {published data only}
    1. Honda K. Quality of vision in pseudophakic persons after extracapsular cataract extraction or phacoemulsification‐aspiration. Japanese Journal of Clinical Ophthalmology 1995;49(4):763‐6.
Kim 1996 {published data only}
    1. Kim JW. Comparative study of intraocular pressure change after cataract surgery: phacoemulsification and extracapsular cataract extraction. Korean Journal of Ophthalmology 1996;10(2):104‐8. - PubMed
Lagreze 1996 {published data only}
    1. Lagreze WD, Bomer TG, Funk J. Effect of surgical technique on the increase in intraocular pressure after cataract extraction. Ophthalmic Surgery and Lasers 1996;27(3):169‐73. - PubMed
Li 2005 {published data only}
    1. Li Y, Wang CY, Wu LA, Ni W, Zhang L, Yang XG. Early clinical research on tear film stability changes after surgery for age‐related cataract. International Journal of Ophthalmology 2005;5(4):677‐80.
Liu 1995 {published data only}
    1. Liu Y, Li S. Reduction of induced corneal astigmatism after IOL implantation by small incision technique. Eye Science 1995;11(4):202‐4. - PubMed
Liu 2003a {published data only}
    1. Liu J, Xu J, He M. Comparing patients' vision function after phacoemulsification with intraocular lens implantation with that after extracapsular cataract extraction with intraocular lens implantation. Chinese Journal of Clinical Rehabilitation 2003;7(1):30‐1.
Liu 2003b {published data only}
    1. Liu JW, Xu JJ, He MG. Comparing patients' quality of life after phacoemulsification with intraocular lens implantation with that after extracapsular cataract extraction with intraocular lens implantation. Chinese Journal of Ophthalmology 2003;39(2):94‐7. - PubMed
Loo 2004 {published data only}
    1. Loo CY, Kandiah M, Arumugam G, Goh PP, John E, Gurusami B, et al. Cost efficiency and cost effectiveness of cataract surgery at the Malaysian Ministry of Health ophthalmic services. International Ophthalmology 2004;25(2):81‐7. - PubMed
Lupidi 1994 {published data only}
    1. Lupidi G, Diotallevi A, Tomassoni I, Feraudo M, Checcucci M, Mancinelli G. Postoperative astigmatism after phacoemulsification and ECCE. Annali di Ottalmologia e Clinica Oculistica 1994;120(10):593‐7.
Ma 2000 {published data only}
    1. Ma X, Li J, Wang J. Investigation on the results of posterior chamber intraocular lens implantation after different operative methods for diabetic patients. Chinese Ophthalmic Research 2000;18(4):364‐6.
Matheu 1997 {published data only}
    1. Matheu A, Castilla M, Duch F, Martí M, Lillo J, Gil M. Manual nucleofragmentation and endothelial cell loss. Journal of Cataract and Refractive Surgery 1997;23(7):995‐9. - PubMed
Moulick 2009 {published data only}
    1. Moulick PS, Rodrigues FE, Shyamsundar K. Evaluation of posterior capsular opacification following phacoemulsification, extracapsular and small incision cataract surgery. Medical Journal Armed Forces India 2009;65(3):225‐8. - PMC - PubMed
Müller‐Jensen 1996 {published data only}
    1. Müller‐Jensen K, Barlinn B, Zimmerman H. Astigmatism reduction: No‐stitch 4.0 mm versus sutured 12.0 mm clear corneal incisions. Journal of Cataract and Refractive Surgery 1996;22(8):1108‐12. - PubMed
Muralikrishnan 2004 {published data only}
    1. Muralikrishnan R, Venkatesh R, Venkatesh Prajna N, Frick KD. Economic cost of cataract surgery procedures in an established eye care centre in Southern India. Ophthalmic Epidemiology 2004;11(5):369‐80. - PubMed
Okinami 1994 {published data only}
    1. Okinami S, Hiroishi G, Saitou I, Iwaki M, Ogino N, Matsumura M, et al. Intraocular lens implantation in eyes with uveitis. Japanese Journal of Clinical Ophthalmology 1994;48(4):739‐44.
Ram 2001 {published data only}
    1. Ram J, Pandey SK, Apple DJ, Werner L, Brar GS, Singh R, et al. Effect of in‐the‐bag intraocular lens fixation on the prevention of posterior capsule opacification. Journal of Cataract and Refractive Surgery 2001;27(7):1039‐46. - PubMed
Sun 2010 {published data only}
    1. Sun XY, Li YZ, Qian T. Correction of corneal astigmatism by topography‐guided incision in cataract surgery. International Journal of Ophthalmology 2010;10(3):462‐5.
Watson 1992 {published data only}
    1. Watson A, Sunderraj P. Comparison of small‐incision phacoemulsification with standard extracapsular cataract surgery: Postoperative astigmatism and visual recovery. Eye 1992;6(6):626‐9. - PubMed
Yasuyoshi 1995 {published data only}
    1. Yasuyoshi H, Yokotani K, Miki M. Progression of diabetic retinopathy following different procedures of cataract surgery. Japanese Journal of Clinical Ophthalmology 1995;49(12):1795‐8.

References to studies awaiting assessment

Durovic 2004 {published data only}
    1. Durovic BM. Endothelial trauma in the surgery of cataract [Trauma endotela kod hirurskog lecenja katarakte]. Vojnosanitetski Pregled 2004;61(5):491‐7. - PubMed
Trnavec 1997 {published data only}
    1. Trnavec B, Cuvala J, Cernák A, Vodrázková E. Comparison of corneal endothelial cells after ECCE and phacoemulsification of the lens [Porovnanie nálezu endoteliálnych buniek rohovky po ECCE a fakoemulzifikácii sosovky]. Ceská a Slovenská Oftalmologie 1997;53(4):240‐3. - PubMed

Additional references

Ang 2012
    1. Ang M, Evans JR, Mehta JS. Manual small incision cataract surgery (MSICS) with posterior chamber intraocular lens versus extracapsular cataract extraction (ECCE) with posterior chamber intraocular lens for age‐related cataract. Cochrane Database of Systematic Reviews 2012, Issue 4. [DOI: 10.1002/14651858.CD008811.pub2] - DOI - PubMed
Apple 1989
    1. Apple DH, Marmalis N, Olson RJ, Kincaid MC. Intraocular Lenses: Evolution, Designs, Complications, and Pathology. Baltimore: Williams & Wilkins, 1989.
Duane 1986
    1. Duane T. Textbook of Ophthalmology. Lippincott‐Raven, 1986.
Glanville 2006
    1. Glanville JM, Lefebvre C, Miles JN, Camosso‐Stefinovic J. How to identify randomized controlled trials in MEDLINE: ten years on. Journal of the Medical Library Association 2006;94(2):130‐6. - PMC - PubMed
Haripriya 2012
    1. Haripriya A, Chang DF, Reena M, Shekhar M. Complication rates of phacoemulsification and manual small‐incision cataract surgery at Aravind Eye Hospital. Journal of Cataract and Refractive Surgery 2012;38(8):1360‐9. - PubMed
Higgins 2011
    1. Higgins JPT, Altman DG, Sterne JAC (editors). Chapter 8: Assessing risk of bias in included studies. In: Higgins JPT, Green S (editors). Cochrane Handbook for Systematic Reviews of Interventions Version 5.1.0 (updated March 2011). The Cochrane Collaboration, 2011. Available from www.cochrane‐handbook.org.
Kirkham 2010
    1. Kirkham JJ, Dwan KM, Altman DG, Gamble C, Dodd S, Smyth R, et al. The impact of outcome reporting bias in randomised controlled trials on a cohort of systematic reviews. BMJ 2010;340:c365. - PubMed
Kuper 2008
    1. Kuper H, Polack S, Eusebio C, Mathenge W, Wadud Z, Foster A. A case‐control study to assess the relationship between poverty and visual impairment from cataract in Kenya, the Philippines, and Bangladesh. PLoS Medicine 2008;5(12):e244. - PMC - PubMed
Lewallen 2002
    1. Lewallen S, Courtright P. Gender and use of cataract surgical services in developing countries. Bulletin of the World Health Organization 2002;80(4):300‐3. - PMC - PubMed
Nangrejo 2011
    1. Nangrejo KM, Sahto AA, Pechuho MA, Siddiqui SJ, Abbassi AM. Visual outcome, phacoemulsification versus extracapsular cataract extraction. Medical Channel 2011;17(3):29‐31.
Passolini 2004
    1. Passolini D, Mariotti SP, Pokharel GP, Pararajasegarm R, Etyalale D, Negrel AD, et al. 2002 global update of available data on visual impairment:a compilation of population‐based prevalence studies. Ophthalmic Epidemiology 2004;11(2):67‐115. - PubMed
Perera 2007
    1. Perera R, Glasziou P. A simple method to correct for the design effect in systematic reviews of trials using paired dichotomous data. Journal of Clinical Epidemiology 2007;60(9):975‐8. - PubMed
Polack 2008
    1. Polack S, Kuper H, Eusebio C, Mathenge W, Wadud Z, Foster A. The impact of cataract on time‐use: results from a population based case‐control study in Kenya, the Philippines and Bangladesh. Ophthalmic Epidemiology 2008;15(6):372‐82. - PubMed
Polack 2010
    1. Polack S, Eusebio C, Mathenge W, Wadud Z, Rashid M, Foster A, et al. The impact of cataract surgery on activities and time‐use: results from a longitudinal study in Kenya, Bangladesh and the Philippines. PloS One 2010;5(6):e10913. - PMC - PubMed
Resnikoff 2004
    1. Resnikoff S, Passolini D, Etyalale D, Kocur I, Pararajasegarm R, Pokharel GP, et al. Global data on visual impairment in the year 2002. Bulletin of The World Health Organization 2004;82(11):844‐51. - PMC - PubMed
RevMan 2012 [Computer program]
    1. The Nordic Cochrane Centre, The Cochrane Collaboration. Review Manager (RevMan). Version 5.2. Copenhagen: The Nordic Cochrane Centre, The Cochrane Collaboration, 2012.
Riaz 2006
    1. Riaz Y, Mehta JS, Wormald R, Evans JR, Foster A, Ravilla T, et al. Surgical interventions for age‐related cataract. Cochrane Database of Systematic Reviews 2006, Issue 4. [DOI: 10.1002/14651858.CD001323.pub2] - DOI - PMC - PubMed
Riaz 2013
    1. Riaz Y, 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. Cochrane Database of Systematic Reviews 2013, Issue 10. [DOI: 10.1002/14651858.CD008813.pub2] - DOI - PMC - PubMed

References to other published versions of this review

Riaz 2010
    1. Riaz Y, Malik ANJ, Evans JR. Phacoemulsification with posterior chamber intraocular lens versus extracapsular cataract extraction (ECCE) with posterior chamber intraocular lens for age‐related cataract. Cochrane Database of Systematic Reviews 2010, Issue 11. [DOI: 10.1002/14651858.CD008812] - DOI - PMC - PubMed

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