Cataract Surgeryin the

Developing World

Dr Brad TownendBSc(Med), MBBS, MPH, MMED, FRANZCO

A Blinding Problem…• Cataract is the leading cause of blindness in the world

– Defined as VA <6/120

• More than 20 million people in the world ‘blind’ due to cataract• 1999: International Agency for the Prevention of Blindness (IAPB) and

the World Health Organization (WHO)

“Vision 2020: The Right to Sight” initiative. • Mission: sustainable provision of high-quality cataract surgical services

throughout the underdeveloped world. • At the start: number of people blinded by cataract projected to double

by year 2020 if no improvements in global eye care delivery• Significant progress has been made in quantity and quality of cataract

surgery provided in Developing World

Q1: What is the leading cause of blindness in the world?

A CataractB GlaucomaC AMDD Infection / Uveitis

Intracapsular Surgery

• No IOL technology• Large wound• Zonule dissolving solution, cryo probe• Time consuming surgery• Ocular complications significant– RD, CMO, expulsive haemorrhage, infection

• Significant morbidity (weeks in hospital)• Remain aphakic with spectacle correction

Harold Ridley• WWII Royal Air Force casualties • Splinters of plastic (acrylic) from shattered

aircraft cockpit canopies became lodged in the eyes of wounded pilots

• Inert (did not trigger rejection or inflammation)

• artificial lenses for cataract surgery• Much opposition from the medical

community initially• Finally approved by FDA as ‘safe and

effective’ for human use in 1981

http://en.wikipedia.org/wiki/File:Plaque_for_Harold_Ridley's_first_intraocular_lens_at_St_Thomas'_Hospital.jpg

Q2: Harold Ridley implanted the first IOL in 1950 made of what material?

A GlassB SiliconC QuartzD Acrylic / Perspex

Extracapsular Surgery

– Preserve capsule for IOL insertion

– 10 mm limbal incision (astigmatism)

– 8-10 sutures

• Astigmatism, time, suture removal, complications

– Slow visual rehabilitation

Phaco-Emulsification• Better refractive and visual outcomes• Quicker surgical time (sutureless)• Fewer complications• Fast rehabilitation

BUT

• High cost of equipment• Maintenance• Consumables• Most blind people live in developing world

Q3: Which of the following is a disadvantage of phaco-emulsification

over traditional extracapsular surgery?

A Faster rehabilitation timeB AstigmatismC CostD No need for sutures

SICSSmall Incision Cataract Surgery

• Good quality outcomes• Cheap ($20 AUD per case)

– Cheap tools– Cheap lenses– No phaco machine– Few consumables (except blades)

• Efficient surgical times (5 minutes) and turnaround times (3 minutes)• Sutureless• Much easier and quicker to learn than phaco• More forgiving than phaco when complications

– Particularly for difficult dense cataracts• Can’t do SICS on soft Western cataracts!• Much fewer post-op visits than ECCE• Better VA outcomes than ECCE, and almost as good phaco

Q4: Which of the following is a limitation of SICS surgery?

A CheapB Difficult to perform on soft

Western cataractsC Efficient surgical timesD Astigmatism

OUTCOMES: SICS vs Phaco in Developing World

• 3 RCT’s• Phaco: more corneal oedema on day 1 post-op with worse VA on day 1• No significant difference in endothelial cell loss between techniques at 6 weeks• Phaco had higher rates of UCVA >6/9 and BCVA >6/6 compared to SICS• At 6 months: rate of BCVA and UCVA >6/18 similar between phaco and SICS• Phaco took 15.5 mins on average, SICS took 9 mins• PCO rate significantly higher in SICS group at 6 months (but VA not worse!)

– Needs longer follow-up

• Complication rates (including endophthalmitis) similar• BUT:

– SICS more efficient and economical– SICS faster visual rehabilitation

(For treating advanced cataracts in the Developing World)

Q5: Which of the following is true for treating advanced cataracts in the Developing World?

A SICS is more efficient, economical and has outcomes that are just as good as phacoB SICS causes more corneal oedema than phacoC Phaco has quicker post-op rehabilitationD SICS has more complications

References• Gogate P, Deshpande M, Nirmalan PK. Why do phacoemulsification? Manual

small-incision cataract surgery is almost as effective, but less expensive. Ophthalmology. 2007;114:965–968.

• Gogate PM, Kulkarni SR, Krishnaiah S, et al. Safety and efficacy of phacoemulsification compared with manual small-incision cataract surgery by randomized controlled clinical trial. Ophthalmology. 2005;112:869–874.

• Ruit S, Tabin G, Chang D, et al. A prospective randomized clinical trial of phacoemulsification vs manual sutureless small-incision extracapsular cataract surgery in Nepal. Am J Ophthalmol. 2007;143:32–38.

• Ruit S, Tabin GC, Nissman SA, Paudyal G, Gurung R. Low-cost high-volume extracapsular cataract extraction with posterior chamber intraocular lens implantation in Nepal. Ophthalmology. 1999;106:1887–1892.

• Tabin G, Chen M, Espandar L. Cataract surgery for the developing world. Curr Opin Ophthalmol. 2008;19:55–59.

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