Round Table Cataract Blindness - Challenges for The 21st Century

Round Table
Cataract blindness – challenges for the 21st century
Garry Brian1 & Hugh Taylor2
Cataract prevalence increases with age. As the world’s population ages, cataract-induced visual dysfunction and
blindness is on the increase. This is a significant global problem. The challenges are to prevent or delay cataract
formation, and treat that which does occur.
Genetic and environmental factors contribute to cataract formation. However, reducing ocular exposure to
UV-B radiation and stopping smoking are the only interventions that can reduce factors that affect the risk of
cataract. The cure for cataract is surgery, but this is not equally available to all, and the surgery which is available
does not produce equal outcomes.
Readily available surgical services capable of delivering good vision rehabilitation must be acceptable and
accessible to all in need, no matter what their circumstances. To establish and sustain these services requires
comprehensive strategies that go beyond a narrow focus on surgical technique. There must be changes in
government priorities, population education, and an integrated approach to surgical and management training.
This approach must include supply of start-up capital equipment, establishment of surgical audit, resupply of
consumables, and cost-recovery mechanisms. Considerable innovation is required. Nowhere is this more evident
than in the pursuit of secure funding for ongoing services.
Keywords: Cataract/etiology/prevention and control; Cataract extraction/standards/economics; Aging; Health
services accessibility; Health care rationing; Lenses, Intraocular/supply and distribution (source: MeSH).
Mots cle´s: Cataracte/e´tiologie/pre´vention et controˆle; Extraction cataracte/normes/e´conomie; Vieillissement;
Accessibilite´ service sante´; Gestion ressources sante´; Cristallin artificiel/ressources et distribution (source: INSERM).
Palabras clave: Catarata/etiolog?´a/prevencio´n y control; Extraccio´n de catarata/normas/econom?´a; Envejeci-
miento; Accesibilidad a los servicios de salud; Asignacio´n de recursos para la atencio´n de salud; Lentes
intraoculares/provisio´n y distribucio´n (fuente: BIREME).
Bulletin of the World Health Organization, 2001, 79: 249–256.
Voir page 254 le re´sume´ en franc¸ais. En la pa´gina 254 figura un resumen en espan˜ol.
Introduction
The prevalence of cataract also increases with
age in developing countries, although it often
Cataract was a significant global problem at the
occurs earlier in life, and there is more of it. For
beginning of the last century, but not widely
example, in an Indian study, visually significant
recognized as such. Today, it is a greater problem,
cataract occurred 14 years earlier than in a
the significance of which is better understood. The
comparable study in the United States (6, 7). The
challenge is to deal with it so that it is no longer a
age-adjusted prevalence of cataract in India was
problem at the beginning of the next century.
three times that of the US, with 82% of Indians of
Increasing age is associated with an increasing
75 to 83 years old having visually significant
prevalence of cataract. Data from Australia show
cataract or aphakia, compared to 46% (senile lens
that this prevalence doubles with each decade of age
changes associated with a visual acuity of 6/9 and
after 40years, so that everyone in their nineties is
worse, or a history of cataract extraction) of those
affected (1). Similar data come from population-
aged 75 to 85 years in the US (6, 7).
based studies in other economically developed parts
Over the next 20years, it is estimated that the
of the world (2–5).
world’s population will increase by about one third
(8). This growth will occur predominantly in
1 Chief Medical Adviser, Fred Hollows Foundation, Locked Bag 100,
developing areas. During the same period, the
Rosebery, New South Wales 1445, Australia
number of people over 65 years of age will more
(email: gbrian@hollows.com.au).
than double (8). This ‘‘greying’’ of the population
2 Professor and Managing Director, Centre for Eye Research Australia.
will occur in both developing and developed
Ref. No. 00-1033
countries.
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Special Theme – Blindness
If nothing else alters, these demographic
70to 80years. In some industrialized countries, a
changes will lead to a doubling in the amount of
combination of legislation and public health educa-
cataract, visual morbidity, and need for cataract
tion has proved effective in reducing smoking and
surgery. The current 20million people with severely
exposure to sun (39, 40). In industrialized countries
reduced vision of 3/60or worse as a result of cataract
the challenge is now to eliminate smoking and make
will have swelled to 40million by the year 2020(8).
UV-B irradiation avoidance the norm in all leisure
The challenge we face is to prevent this from
and work activities. If this were to be achieved, then
occurring by delaying the development of cataract
cataract could be halved (41).
and by providing ready access to cataract surgery for
A far greater challenge will be to accomplish
all those who need it.
this in developing countries. These are often in
regions with high incident light, and have populations
dependent on outdoor agrarian activities, weak
Prevention
legislative capacity with little consumer protection,
and little or no anti-smoking education and promo-
Although many cross-sectional studies of risk factors
tion. In addition, there are many more immediate
for cataract have now been made (9), and the results
imperatives for the daily survival of their people.
of some longitudinal studies are available (10, 11), our
Prospects are poor.
understanding of age-related cataract etiology is
People with diabetes have an increased risk of
incomplete. Secondary cataract is much less common
cortical and posterior subcapsular cataract (9, 16, 25)
and can occur after trauma, intraocular inflammation,
and are also more likely to have early cataract surgery.
exposure to ionizing radiation and other events.
These associations will assume greater importance as
The most exciting recent developments in
diabetes continues to increase in both developing and
cataract epidemiology have been the identification of
industrialized areas. The challenge is to design and
a strong genetic component. Twin studies in the
deliver widespread public health initiatives aimed at
United Kingdom suggest that approximately half of
dietary and physical activity education and behaviour
nuclear and two thirds of cortical cataract can be
change to control this epidemic of diabetes.
accounted for by hereditary factors (12, 13). Domi-
In the United States, a high body mass index
nant genes have been implicated for cortical cataract
increased the risk of developing posterior subcap-
and additive genetic effects for nuclear. These
sular cataract (42). At the other end of the spectrum
findings are generally consistent with those from
of community and individual wealth, studies in India
population-based studies (14–16). However, at this
have shown that severe protein-calorie malnutrition
stage, nothing can be done to alter an individual’s
is more common in people with cataract (6). In
genetic makeup in relation to cataract.
addition, cataract has been linked to severe diarrhoea
‘‘Age’’ in this context almost certainly repre-
and cholera (26, 27). One of the many problems that
sents the cumulative effect of the complex inter-
have to be solved here is inequity of resource and
action of exposure to many factors over time that
opportunity distribution, both within and between
contribute to the development of cataract. Some of
countries (43).
these factors are known, others are not yet identified
As our understanding of the cellular and
or confirmed. Important risk factors for age-related
molecular changes associated with cataract formation
cataract include exposure to ultraviolet-B (UV-B)
becomes refined, the possibility increases of delaying
radiation (2, 5, 16–18), the presence of diabetes
its onset. Initial hopes for the protective use of aspirin
(9, 25), and the use of therapeutic drugs such as
have not been substantiated (32, 44). To date, perhaps
corticosteroids (28–30), and recreational drugs such
with the exception of the antioxidant vitamins A, C,
as nicotine (3, 4, 31) and alcohol (4, 32, 33). The
and E (19), no other serious protective pharmaceutical
occurrence of severe diarrhoea and dehydration have
contender has emerged. The challenges do not end
been suggested by some studies (26, 27), but not by
with the identification and trial of an effective
others (20). The role of dietary antioxidant vitamins is
preventive drug. Depending on its formulation, mass
unclear and often contradictory (19, 21–24).
supply and distribution would need to be organized
The results of studies currently under way on
along the lines of oncherciasis treatment in endemic
the effectiveness of antioxidant vitamin supplements
areas, or perhaps fluoridation of drinking-water.
(34–36) are awaited with interest. Until they or other
The benefits of cataract prevention are
studies prove otherwise, the only known effective
obvious, but unfortunately, the likelihood of achiev-
ways to reduce the risk of cataract seem to be to
ing it is remote. However, a delay of 10years in the
reduce ocular UV-B radiation exposure, and to stop
onset of cataract would, with today’s criteria for
smoking (37). Australian data indicated a population-
surgical intervention, halve the number needing
attributable risk for smoking and nuclear cataract of
surgery. In Australia, where the median age for
17%, and a risk of 10% for UV-B exposure and
developing cataract is in the eighth decade, this
cortical cataract (38). Given the overall prevalences
reduction would be achieved with only a 14% delay in
of the different cataract types, this gives a 14%
the onset rate (41). The challenges of cataract
combined population risk for ‘‘cataract’’ attributable
research, influencing government policy and modify-
to smoking and UV-B exposure. This would translate
ing the behaviour of the public are therefore worth
into a retardation of the median age for cataract from
taking up.
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Cataract blindness – challenges for the 21st century
Treatment
for cataract and clear lens extraction in developed
countries.
The cure for cataract is surgery. However, this
In developing countries, the intracapsular
surgery is not equally available to all, and where it is
cataract extraction threshold has largely persisted,
available it does not produce equal outcomes.
because where surgery is available, this is the
Decisions have to be made, according to the
technique most frequently used. As extracapsular
prevailing circumstances, about how much cataract
cataract extraction with intraocular lens implantation
is enough to warrant surgery, who should have that
becomes more common (43), the threshold will be
surgery, how it should be performed and delivered,
reduced. This will have huge implications for the
and how it should be paid for.
number of operations that need to be done.
How much cataract is enough to warrant
Who should have cataract surgery?
surgery?
With a descending threshold for cataract surgery,
In the strictest sense, ‘‘blindness’’ as a ‘‘total lack of
criteria must be set as to when this procedure is really
sight’’ has never been the criterion for cataract
required. The decision has implications for the
surgery. Indeed, it has been a contraindication.
planning, delivery, financing, and accessibility of
Instead, the criterion has been an ‘‘extreme loss of
cataract surgical services. It is obviously impractical
function’’ as a result of reduced vision, characterized
to declare a single surgical threshold for ‘‘cataract
by an inability for self-care. Usually this is measured
blindness’’ that would be appropriate and acceptable
against the arbitrary scale of ‘‘visual acuity’’. ‘‘Legal
to all, or even a majority, of individuals and
blindness’’, with financial benefits, was first specified
communities. We have to assume there is a
by the 1935 Social Security Act in the United States
distribution of levels of visual impairment (54), and
(45). This approximated a definition of blindness as
define a particular threshold as ‘‘blind and requiring
the vision at which intracapsular cataract extraction
surgery’’, depending on the prevailing social and
would be considered, and the vision with the
economic situation.
resultant uncorrected aphakia.
Definition of such a threshold for a given
Empirically, the quality of vision afforded by
community needs more than just a visual acuity
aphakic correction does not warrant cataract surgery
determination. The daily visual needs of members of
at a threshold better than 6/60or 3/60
. In
that community need to be identified and the
industrialized countries, this threshold persisted
functional implications of disability assessed (54).
during the introduction of intraocular lens implanta-
Questionnaires such as the VF-14 can be useful (49).
tion. However, as the surgery has become consis-
An assessment of the level of disability that family
tently safer, with predictably good vision reha-
and community will tolerate in its members also
bilitation, often without the need for spectacle
should be evaluated. For example: what level of
correction at all, this threshold has decreased. Also,
disability prevents a person from making their usual
there have been increasing social and economic
contribution to their family and community? At what
imperatives to lower the threshold. For example, a
level is another family member required to leave
driving licence is now considered essential for many,
economically active work and provide support? At
even those retired (46). This requires vision of the
what level is a community prepared, where there is a
order of 6/12. The shift from a largely unskilled
pension system, to support a visually disabled
workforce with lesser vision demands, increasing
person? All of these types of information may be
emphasis on leisure pursuits, and greater expecta-
expected to lower the final threshold.
tions concerning quality of life, including for the
According to Australian data (1), and just using
retired, have all contributed to a demand for
visual acuity as the indicator, the number of cataract
sustained good vision. There is also the accumulating
operations needed increases 2.5 times as the thresh-
evidence of increased mortality and morbidity
old changes from < 6/60to < 6/24, and increases
associated with vision reduction (47).
fivefold if it goes to < 6/12 (Fig. 1). In developing
The threshold for cataract surgery in many
countries the increase would probably be more.
industrialized countries is now 6/9 or less (1, 11, 48,
On the other hand, the level of disability at
49). This has resulted in a substantial increase in
which a government or insurer is prepared to pay for
numbers receiving surgery in these countries over the
intervention is likely to raise the final threshold. The
last 20years. Threefold to fourfold increases in a
reality of economic rationing is that, except when
decade have been reported from the United States,
patients pay for their own surgery or are subsidized
Sweden (48, 50), the United Kingdom (51) and
by other paying patients, limited resources will
Australia (52). Cataract surgery now accounts for
limit the total number of surgeries financed. This
more than half the ophthalmic procedures in some
rationing is likely to be reflected in a paucity of
areas, and in several countries it is the most common
surgical facilities, staff and consumables.
elective surgery (52, 53). In recent years, corneal
In rich and poor countries alike, services may
refractive procedures have caused increased public
be rationed by making them unaffordable or
scrutiny of vision and its correction. The pursuit of
inaccessible. Rationing also occurs with the use of
uncorrected ‘‘super-vision’’ of better than 6/6 is on
the ‘‘surgical waiting list’’. For example, in England
the rise. This may translate to an even greater demand
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Special Theme – Blindness
accessible only to people living in their immediate
vicinity. But even where such facilities are available,
there is often a lack of instruments and other
equipment, exacerbated by poor maintenance, with
medications and other consumables in short supply.
Overall, there are not enough cataract surgeons.
In the continent of Africa, for example, there are 500
or so ophthalmologists, about 1:1 000 000 popu-
lation. A considerable number of these are in private
practice, unavailable to the general population (56).
Low government salaries, and conflicts of interest
between private and public practice, diminish the
efficiency of government-employed physicians (57),
who also usually live and work in urban settings. They
are often underutilized, with a low surgical output per
surgeon. Even if working well, their surgical output is
usually insufficient to meet the actual need or the
potential demand. For example, Indian surgeons, on
average, do between 400 and 900 cataract surgeries per
year, depending on whether they are in public or
private practice (58). Also, inefficient use is made of
and Wales there is an estimated cataract backlog of
non-ophthalmologists for routine aspects of vision
2.4 million people with visual impairment (<6/12)
care, often because the majority of paramedical
due to cataract (55). About 160 000 cataract opera-
personnel and general doctors have only superficial
tions are performed each year, with an annual
knowledge of eye conditions. Nor are they widely used
increase of about 7%. However, with 1.1 million
as cataract surgeons, an obvious and achievable
new cases expected over 5 years, death will remove
solution to the problem of insufficient trained
almost as many people from the cataract backlog as
practitioners (57, 59, 60).
are removed by completed surgery.
Where cataract surgical services are made
Once the surgical threshold has been estab-
available, patients may not make use of them. For
lished, the task is to establish widespread access to
example, when rural Kenyans (61) were offered free
services capable of delivering the necessary vision
intracapsular cataract extraction, only 70% agreed to
rehabilitation.
the surgery, and in a Nepalese study (62), even when
offered transport and free surgery, the use rate was
below 60%.
Access to treatment
Poor uptake of services may be because
patients do not know or believe that cataract is
Without trivializing the remaining challenges for
curable. Potential patients may also be unaware of the
industrialized countries in this regard, it has to be
possibility of an operation, or of the availability of a
recognized that the real challenges here are in the
particular surgical service. Or, they may have no
developing ones.
previous experience of successful cataract surgery.
Where there is wealth, it is a maldistribution of
Large numbers of people who are irreversibly blind
surgeons and facilities, outmoded and inefficient
because of surgical complications, or functionally
work practices, personal greed, indifferent profes-
blind with uncorrected aphakia, may be deterrents to
sionalism, and budgetary constraints that combine to
accessing available services. Also, aphakic spectacles
limit equitable access to cataract surgery. However, in
may be regarded as the brand of a cripple. Poor
a largely open society with high literacy rates, a free
outcomes, whether due to poor patient selection or
press, an informed public, and organized professional
poor surgery, can erode trust and contribute to a
and special interest groups, the quality and use of
facility’s bad reputation.
cataract services are likely to be improved by
There may also be misconceptions about
vigilance, debate and compromise.
cataract surgery, such as still waiting for the cataract
In developing countries there are many more
to mature when intraocular lens implantation is
solid barriers to the availability of, access to, and
possible earlier. Or, there may be fatalism about
uptake of cataract surgery. It is these that we must
blindness. Practices of traditional medicine are often
identify, scrutinize and overcome. Although the
associated with religious beliefs and mystification.
desire to do this may be present, generally, the
Belief in magical cures influences a population’s
impetus and resources to initiate it will not come
attitude towards modern health practices and treat-
from within these countries, but elsewhere.
ments, including cataract surgery. Frequently, it is
The vast majority of cataract patients in
difficult to provide better information for potential
developing countries live in rural areas, while hospitals
patients and dispel discouraging misinformation.
and surgical facilities are frequently in the cities and
Even where these obstacles do not prevent
larger towns. In practice, generally, these facilities are
surgery, the monetary and other costs of services may
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Cataract blindness – challenges for the 21st century
be beyond the reach of community, family, or
The work of the Fred Hollows Foundation in
individual resources. These cost impediments may
cataract-related projects in Africa and Asia is a further
include the distance to such services, lack of
example (59, 78). The integrated approach to cataract
transport, having no one to act as escort and carer,
surgery offered by the Foundation varies according
and seasonal work demands on partially sighted
to local circumstances, but may consist of surgical
patients and their families.
and management training, supply of start-up capital
The international ophthalmic community has
equipment, and help in setting up surgical audit,
largely concentrated on the technicalities of cataract
consumables resupply, and cost recovery mechan-
surgery in developing areas. During the last 15 years,
isms (43, 59).
much effort has been directed to identifying the best
It is only through an integrated approach that
operative procedure. There was controversy, even
the challenge of creating widespread access to
though the answers were often already known from
surgical services capable of delivering good quality
experience in developed countries, but extracapsular
vision rehabilitation will be met. Then we must
cataract extraction with posterior chamber lens
ensure that those without the personal resources to
implantation (63, 64) is now widely accepted as the
afford choice of service can access these services.
procedure of choice (58, 65–69). It is recommended
Generally it is those most in need who are least able to
because its results are better than those obtained with
influence community politics and who suffer most
the alternatives (70–72). Also, equipment such as the
from unjust choices.
robust, affordable, portable microscope and YAG
laser produced by the Fred Hollows Foundation in
collaboration with Australian industry, are now
Paying for treatment
available.
The industrialized world is fiscally challenged by an
apparently insatiable demand for medical technology
The question of quality
and services. Whether under the guise of ‘‘managed
Much of what has happened in the last 15 years has
care’’, priority listing of interventions or some other
been driven by the relatively easily met need to
system, attempts to control expenditure will continue
achieve increased surgical output, rather than by a
to incite public and professional debate. From this
regard for vision outcome and rehabilitation. Con-
debate, a position of compromise and common good
cern about the audit of outcome and quality
is expected to arise. In developing countries, political
assurance is relatively recent. This has revealed that
elites are under much more pressure to allocate
despite all the attention to cataract surgical detail,
severely limited resources to priorities other than
postoperative vision results are less positive than
cataract services. Unless patients pay for their own
anticipated, and complication rates are greater. For
surgery and subsidize that of those who cannot afford
example, assessment of urban Indian surgery (73)
it, widespread surgery will not be sustained.
showed 21% of patients had a very poor outcome
An alternative approach is to develop a direct
(presenting visual acuity of worse than 6/60), with
link between cataract services and revenue-generating
another 35% having poor outcome (6/18 to 6/60). In
industry (43). Such an arrangement should involve the
neighbouring Nepal, 21% are still blind postopera-
most modern technologies in value-adding industries
tively with presenting visual acuity of <6/60in both
(81). This will accelerate economic development,
eyes. However, this improves to 7% with best
finance services for those unable to afford them, and
correction (74, 75). Opacification of the posterior
greatly reduce dependence on government funding.
capsule can occur, but it rarely causes blindness (76).
The challenge of such development may seem beyond
More effort needs to be directed to improving the
the interest or influence of ophthalmologists (82), but
quality of cataract surgery (74, 77), through improve-
in fact this is not the case. Consider an example: the
ment in areas such as case selection and postoperative
manufacture of intraocular lenses (83).
care, rather than just concentrating on surgical
Observations of pharmaceutical production in
technique and volume.
the worst of circumstances in Eritrea, a country then
The surgical act plays only a small part in the
at war, showed that intraocular lens manufacture was
cure of cataract. It must be supported by a whole
possible (83). The Fred Hollows Foundation has
gamut of linked activities: training and ongoing
acted on this and similar information to establish
development for surgeons, nurses and administra-
manufacturing facilities in both Eritrea and Nepal
tors; equipment purchase, maintenance, and replace-
(84). Each is run by a local management board and
ment; the ordering and supply of consumables; cost
staff. Research and development have led to the
recovery with patient cross-subsidization so the very
incorporation of technology that is more sophisti-
poor have equitable access; improving management
cated than that used in comparable Western produc-
capability and commitment; planning; and fostering
tion. Now, as these commercial enterprises move
recipient ownership. Integration and coordination of
into profit, ownership is being transferred to
all these activities, as well as many others, are required
indigenous organizations. Individuals and their
for a successful sustainable cataract intervention (78).
communities have directly benefited from these
In India, the effective work of the Aravind Hospital
lens factories — through education, salary, and an
system is testimony to this (79, 80).
affordable intraocular lens for local use. Major
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Special Theme – Blindness
advantages also come with the export of the
Conclusion
internationally certified intraocular lenses produced,
and the foreign exchange this generates.
Cataract is a significant and increasing global
It will be obvious that not every developing
problem. The challenges are to prevent or delay
country needs or wants an intraocular lens factory.
cataract formation, and cure that which does occur.
However, even in the commercial context of a small
Preventive interventions must be identified, per-
medical discipline such as ophthalmology, the manu-
fected and delivered, through research, changes in
facturing and service opportunities are many, and
government policy and legislation, and modification
include sutures, surgical instruments, other equip-
of community and individual behaviour.
ment, pharmaceuticals, education and information
Widespread surgical services capable of deli-
materials and other such supplies. The international
vering good vision rehabilitation must be acceptable
ophthalmic community could contribute to this
and accessible to all in need, no matter what their
development process either by raising the capital
circumstances. To establish and sustain these
for a commercial enterprise or by using products
services requires comprehensive strategies going
manufactured in such circumstances in its everyday
well beyond a narrow focus on surgical technique.
work, provided they are of comparable quality to those
There must be changes in government priorities,
made in the West. Where such products are not
population education, and, where missing, an
available, the collective purchasing power of ophthal-
integrated approach to surgical and management
mologists could be used to encourage producers in
training, with supply of start-up capital equipment,
industrialized countries to enter suitably structured
and help in setting up surgical audit, consumables
joint ventures in the developing world. Only with
resupply and cost recovery mechanisms. Consider-
unconventional approaches such as these will cataract
able innovation is required. Nowhere is this more
surgery be available in the long term to those who are
evident than in the pursuit of secure funding for
at present the least able to get access to it and pay for it.
ongoing services. n
Re´sume´
Ce´cite´ due a` la cataracte – Les enjeux pour le XXIe sie`cle
La pre´valence de la cataracte augmente avec l’aˆge. A
tous ceux qui en ont besoin quelle que soit leur situation,
mesure que la population mondiale vieillit, les dysfonc-
et acceptables par tous. La mise en place durable de ces
tionnements visuels et la ce´cite´ dus a` la cataracte
services suppose des strate´gies comple`tes qui aillent au-
augmentent, ce qui repre´sente un proble`me important
dela` des simples techniques chirurgicales. Il convient en
partout dans le monde. Les enjeux consistent donc a`
effet aussi de modifier les priorite´s gouvernementales,
pre´venir ou a` retarder l’apparition de la cataracte et a` la
d’e´duquer la population et d’adopter une approche
traiter lorsqu’elle survient.
inte´gre´e de la formation a` la prise en charge et a` la
Des facteurs ge´ne´tiques et environnementaux
chirurgie.
contribuent a` l’apparition de la cataracte. Les seules
Cette de´marche doit comprendre la fourniture
interventions susceptibles de re´duire les facteurs de
de mate´riel de base, l’e´tablissement d’un controˆle
risque consistent a` diminuer l’exposition oculaire aux
sur le plan chirurgical, le re´approvisionnement en
rayonnements UV-B et a` cesser de fumer. La cataracte
fournitures renouvelables et des me´canismes de
s’ope`re tre`s bien, mais l’ope´ration n’est pas a` la porte´e
re´cupe´ration des couˆts. Des innovations conside´-
de tous et les me´thodes chirurgicales ne donnent pas les
rables s’imposent, particulie`rement en ce qui
meˆmes re´sultats partout.
concerne la recherche d’un financement durable
Des services chirurgicaux capables de garantir une
des services.
bonne re´cupe´ration de la vision doivent eˆtre accessibles a`
Resumen
Ceguera por catarata: retos para el siglo XXI
La prevalencia de la catarata aumenta con la edad. A
el riesgo de catarata. La curacio´n se consigue so´lo con
medida que envejece la poblacio´n mundial, aumentan
tratamiento quiru´rgico, pero no todo el mundo puede
tambie´n los casos de disfuncio´n visual y ceguera por
acceder a e´l, y las intervenciones quiru´rgicas disponibles
catarata. Se trata de un problema mundial importante,
tienen resultados dispares.
que nos desaf?´a a prevenir o retrasar la formacio´n de
Es necesario que todas las personas necesitadas,
cataratas y a tratar todos los casos que aparezcan.
cualesquiera que sean sus circunstancias, puedan
A la formacio´n de la catarata contribuyen factores
acceder fa´cilmente a servicios quiru´rgicos aceptables,
tanto gene´ticos como ambientales. Sin embargo, la
capaces de restablecer debidamente la vista. Para
reduccio´n de la exposicio´n a la radiacio´n UV-B y el
establecer y sostener estos servicios se requieren
abandono del tabaco son las u´nicas medidas que
estrategias amplias que no se detengan en la simple
permiten reducir la influencia de factores que inciden en
te´cnica quiru´rgica. Hay que introducir cambios en las
254
Bulletin of the World Health Organization, 2001, 79 (3)

---

Cataract blindness – challenges for the 21st century
prioridades de la Administracio´n y la educacio´n de la
control de las intervenciones quiru´rgicas, la reposicio´n
poblacio´n, y enfocar de forma integrada la capacitacio´n
del material fungible y los mecanismos de recuperacio´n
en el manejo y el tratamiento quiru´rgico de esta dolencia.
de costos. Se requiere para ello una innovacio´n
Forman parte de ese enfoque el suministro de bienes
considerable, lo que resulta especialmente evidente a
de equipo iniciales, el establecimiento de sistema de
la hora de buscar fondos para los servicios en marcha.
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