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.

F I J I

N E P A L

A L I C E S P R I N G S

EYE CHART:How to be cruel to old guys!