Tackling the greatest challenge in cataract surgery

Despite all that modern technology has done to advance the treatment of cataracts, our greatest challenge continues to be the large and increasing backlog of cataract blindness in developing countries.^1–5 While in North America and western Europe, intraocular lens (IOL) research and development are primarily directed towards reversing lens ageing (presbyopia), millions in developing nations with reversible blindness caused by cataracts go untreated.

Modern phacoemulsification machines are expensive to purchase and maintain, have relatively high disposable costs, and require extensive surgical training. Furthermore, for the more advanced and mature cataracts typical of underserved populations, performing phacoemulsification becomes more difficult and complication prone. What is needed is a high volume, cost effective, low technology procedure that can treat the most advanced of cataracts with a low complication rate in the shortest amount of time.

This very goal is being achieved in a handful of international programmes that are providing a hopeful paradigm for overcoming worldwide cataract blindness. I have had the privilege of visiting both the Aravind Eye Hospital network in southern India, and the Tilganga Eye Centre in Kathmandu, Nepal. Seeing first hand how their systems provide high volume, low cost cataract surgery is an awe inspiring experience for any visiting ophthalmologist.

Founded in 1976 by the now 87 year old Dr G Venkataswamy, Aravind Eye Hospital has grown into a network of five regional eye hospitals providing high level ophthalmic care to the poor population of southern India. Private paying patients comprise approximately 30% of their patient base. This revenue funds 70% of their services that are provided at no cost to the indigent via a financially self sustaining programme that receives minimal government reimbursement. In terms of cataract surgery, this means that of the approximately 200 000 procedures performed annually in the Aravind system, 70% are provided free.

While private cataract patients at Aravind may pay anywhere from $200–$300 to undergo phacoemulsification with foldable IOLs imported from the United States, the non-paying cataract patients are treated for less than $15 per case, including the IOL. This is accomplished by performing a manual, sutureless, small incision extracapsular procedure with re-usable equipment and supplies.^6–9 Their IOL manufacturing facility, Aurolab, produces poly(methlymethacrylate) (PMMA) IOLs for less than $5 per lens. Following a retrobulbar block, the nucleus is expressed through a capsulorhexis and a temporal, self sealing 6.0–6.5 mm scleral pocket incision. Manual cortical cleanup precedes capsular bag implantation of a PMMA IOL. The technique is commonly abbreviated as manual SICS (small incision cataract surgery).

An efficient, high volume system utilising low cost, sub-5 minute procedures to tackle advanced cataracts with minimal complications is clearly the best way to use the scarcest and most precious asset of the system—the cataract surgeon

While the procedure itself seems straightforward, it is the stunning speed, skill, and efficiency with which it is performed that must literally be seen to be believed. By alternating between two parallel operating room tables, a single surgeon is able to perform over 15 cases per hour by consistently completing sub-5 minute procedures on the densest of cataracts with no intervening turnover time. To ensure efficiency across different surgical teams, every aspect of the procedure is standardised, from preoperative patient and instrument preparation to the surgical steps themselves. Having been screened in outlying eye camps, as many as 300–400 cataract patients will by bussed to an Aravind eye hospital where they will all undergo their surgery on a single day. After several days of in-house follow up, they are transported back to their rural villages where a local postoperative visit and refraction are performed 1 month later by the Aravind staff. This standardised Aravind system streamlines and centralises cataract care by performing all surgery in the main hospital.¹⁰

Founded in 1994 by Dr Sanduk Ruit, the Tilganga Eye Centre is a shining example of an efficient eye care delivery system on a smaller scale. Dr Ruit has developed his own variation of the manual, sutureless SICS.^11–13 Tilganga Eye Centre is also financially self sustaining wherein private care subsidises charity care. They also have their own IOL manufacturing facility, which, like that at Aravind, is able to supply low cost IOLs to other developing countries. Because the rural population in Nepal is so widely scattered among mountain villages that are accessible only by foot, the Tilganga system strives to deliver portable cataract care by transporting the necessary staff and equipment to remote eye camps.^14,15 Using a single portable operating table, the Tilganga surgeons can also perform more than 10 cataract surgeries per hour. As at Aravind, the high volume, cost effective Tilganga surgical techniques and protocols are standardised across their surgical teams.

Though of a different scale and serving different types of communities, Aravind and Tilganga are complementary models of how best to address the world’s backlog of cataract blindness. They demonstrate that the solution requires not just a cost effective surgical technique, but also an entire system of efficient and financially self sustaining cataract care delivery. There must be a system for attracting, screening, diagnosing, and transporting cataract patients to and from rural camps. There must be a source of low cost IOLs, medications, and supplies. Most importantly, there must be highly coordinated teams of dedicated ophthalmologists and support staff, who execute their roles with military precision. To assure maximum efficiency and reproducibility, there must be a standard protocol for every aspect of care.

In this issue of BJO (p 1079), Venkatesh and co-authors provide a detailed outcome study of the high volume, manual SICS (small incision cataract surgery) method used at Aravind. Two days’ surgical volume for three cataract surgeons (∼600 cases) were randomly selected and reviewed retrospectively. Despite a high percentage of advanced and mature cataracts, operative complications were extremely low, and vitreous loss occurred in less than 1% of cases. Understandably, stringent postoperative outcome data with long term follow up are not easily attainable in a rural cataract camp population. However, with 6 week follow up of nearly 90% of the patients, 95% achieved a best corrected visual acuity of at least 6/18 (not excluding macular or other pathology). These outcomes are all the more impressive considering that almost 90% of the patients had preoperative vision of 5/60 or worse, and that the surgical time for these nearly 600 patients averaged 3.75 minutes.

How does the manual, sutureless SICS compare to other cataract methods? One prospective randomised study determined that this technique resulted in better uncorrected acuity than standard extracapsular cataract extraction.¹⁶ Astigmatism control is particularly important in populations that have limited access to spectacles. I recently participated in a prospective randomised trial at the Tilganga Eye Centre comparing manual, sutureless SICS with phaco in a cataract camp population. While the data analysis is not complete, I can attest to the difficulty of performing phaco in a camp setting with a high incidence of advanced cataracts and poor corneal visibility. Finally, from the standpoint of cost effectiveness, manual SICS is clearly superior to the alternatives.^17,18

Outcome studies such as these provide convincing evidence that surgical systems, such as those at Aravind and Tilganga, are the most promising, efficacious, and cost effective means to eradicate cataract blindness in developing countries. Beyond the impressive productivity of these two institutions, equally important has been their desire and ability to train surgical teams from other developing countries in their methods of cataract surgery. An efficient, high volume system utilising low cost, sub-5 minute procedures to tackle advanced cataracts with minimal complications is clearly the best way to use the scarcest and most precious asset of the system—the cataract surgeon.