点击显示 收起
Correspondence to:
N Congdon
Wilmer Eye Institute John Hopkins Hospital 600 N Wolfe Street Baltimore, MD 21287, USA; ncongdon@jhmi.edu
Renewed vision for years to come
Keywords: cataract extraction; visual function
Cataract is the leading cause of blindness in the world,1 and the leading cause of low vision in European derived populations.2 The burden of cataract is likely to increase as the world’s population ages.2 At present, no effective means of preventing cataract exists, with the possible exception of smoking cessation.3 For the foreseeable future, the sole method of preventing cataract blindness will remain the surgical removal of the opacified lens. Fortunately, successful results are the rule rather than the exception with cataract surgery in the developed world4–6 and many parts of the developing world.7,8 Fully 90% of people undergoing cataract surgery can expect to attain vision of 6/12 or better postoperatively,4,5 and a similar proportion report being satisfied with their surgery.6
The fact that cataract remains an important cause of blindness in the developing world, and even in parts of the developed world,9 suggests that a commitment to improved access to cataract surgical services is required. However, the widespread provision of such services can be expensive: the annual cost of cataract surgery in the United States, for example, exceeds $US3 billion,10 and some two thirds of the US Medicare budget is expended on the examination and treatment of cataract.11 The strongest argument in favour of increasing expenditures to combat cataract blindness has been the contention that cataract extraction is a highly cost effective surgery.12,13 However, as the authors of the paper in this issue of the BJO (p 1017), note, "three variables must be known in order to support (the) statement (that cataract surgery is cost effective)." While data on the cost of cataract surgery and its impact on vision have generally been widely available, the paper by Lundstrom and Wendel is one of the first to provide evidence on the duration of improved visual function after surgery.
While Lundstrom and Wendel indicate that the proportion of subjects reporting improved vision after surgery declines, not surprisingly, with longer follow up, their conclusion that 80% still have improved function 7 years after surgery is, none the less, extremely encouraging. Healthcare policy makers and governmental and non-governmental organisations engaged in the provision of eye care should be motivated by the fact that currently available surgical treatment for the world’s leading cause of blindness is capable not only of bringing renewed sight now, but for many years to come.
REFERENCES
Thylefors B, Negrel AD, Pararajasegaram R, et al. Global data on blindness. Bull World Health Organization 1995;73:115–21.
Congdon N, O’Colmain B, Klaver CC, et al. Causes and prevalence of visual impairment among adults in the United States. Arch Ophthalmol 2004;122:477–85.
McCarty CA, Nanjan MB, Taylor HR. Attributable risk estimates for cataract to prioritize medical and public health action. Invest Ophthalmol Vis Sci 2000;41:3720–5.
Desai P, Minassian DC, Reidy A. National cataract surgery survey 1997–98: a report of the results of clinical outcomes. Br J Ophthalmol 1999;83:1336–40.
Stenevi U, Lundstrom M, Thorburn W. An outcome study of cataract surgery based on a national register. Acta Ophthalmol Scand 1997;75:688–91.
Lundstrom M, Stenevi U, Thorburn W, et al. Catquest questionnaire for use in cataract surgery care: assessment of surgical outcomes. J Cataract Refract Surg 1998;24:968–74.
Prajna NV, Chandrakanth KS, Kim R, et al. The Madurai Intra-Ocular Lens Study. II: Clinical outcomes, Am J Ophthalmol 1998;125:14–25.
Yorston D, Foster A. Audit of extra-capsular cataract extraction and posterior chamber lens implantation as a routine treatment for age-related cataract in East Africa. Br J Ophthalmol 1999;83:897–901.
Sommer A, Tielsch JM, Katz J, et al. Racial differences in the cause-specific prevalence of blindness in east Baltimore. N Engl J Med 1991;325:1412–17.
Javitt JC. Who does cataract surgery in the United States? Arch Ophthalmol 1993;111:1329.
Ellwein LB, Urato CJ. Use of eye care and associated charges among the Medicare population: 1991–98. Arch Ophthalmol 2002;120:804–11.
Kobelt G, Lundstrom M, Stenevi U. Measuring utility and outcome in cataract surgery. J Cataract Refract Surg 2002;28:1742–9.
Busbee BG, Brown MM, Brown GC, et al. Incremental cost-effectiveness of initial cataract surgery. Ophthalmology 2002;109:606–13.