doi: 10.1161/01.STR.0000204088.04384.74
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(Stroke. 2006;37:766-a.)
© 2006 American Heart Association, Inc.
Letters to the Editor |
Cataract Surgery After Acute Stroke: Maybe More Than a Coincidence
Department of Clinical Geratology, University of Oxford, Oxford, UK, Department of Family Medicine, Taipei Veterans General Hospital, National Yang Ming University, School of Medicine, Taipei, Taiwan
Department of Clinical Geratology, University of Oxford, Oxford, UK
Department of Family Medicine, Taipei Veterans General Hospital, National Yang Ming University, School of Medicine, Taipei, Taiwan
Oxford Brooke University, School of Health and Social Care, Oxford, UK
To the Editor:
Cataract and stroke are 2 common pathologies in the elderly population. The need of cataract surgery in the UK approximates 200 000 a year, and >2.4 million people aged over 65 experienced cataracts with visual impairment in 1 eye or 2. This number increases by 1.1 million over a 5-year period.1 About 5% of patients undertaking cataract surgery reported a past history of stroke.2 Most stroke patients experience various levels of functional impairment which may, on the one hand, limit them from having cataract surgery, but, on the other hand, they may have a stronger drive to improve their visual acuity after stroke.
Oxford Radcliffe Hospital (ORH) Trust is the only general hospital providing acute stroke care, so the majority of patients in Oxfordshire contracting acute stroke would be sent to ORH for treatment. A retrospective chart survey of acute stroke inpatients in ORH Trust in 2003 to 2004 was done to explore the relationship between stroke and cataract surgery. In 2003, 735 acute stroke inpatient records (mean age=77.3±13.4 years, 47.9% males) were sorted by ICD-10 (I619, I639, I64X) and were followed through 2004 with the mean follow-up of 377.8 days. At discharge, 213 (28.9%) died at the stroke events, 281 (53.8%) went back home with care package, 15 returned to nursing homes (2.9%), and 226 (43.3%) were transferred for intermediate care. In 2004, 20 patients (3.8%) died, mostly because of infectious complications and recurrent cardiovascular events. Among the 522 stroke survivors, 138 (26.4%) of them were readmitted, and 11 cataract surgeries were performed during the follow-up period. Four hundred and sixteen stroke survivors from 2003 to 2004 were aged over 64. Patients undertaking cataract surgery after stroke were aged over 64 (median age=77 years, range: 65 to 87 years), and none of them had been transferred to any form of intermediate care, implying that they perhaps recovered better from stroke events. In 1999 to 2000, 
164 000 cataract surgeries were performed for patients aged over 64 in England and Wales, and the cataract surgery rate of people aged over 64 was 1.9% in England and Wales.3,4 Cataract surgery rate in stroke survivors aged over 64 was 2.6% (11/416) in our study, which was higher than the national survey.
Is this discovery merely a coincidence between common pathology in the elderly? Maybe yes and maybe no. Hu et al reported that cataract extraction surgery was positively related to coronary heart diseases, and oxidative damages were considered the cause of both conditions.5 In addition, does head CT scans done during acute stroke events predispose cataract? Previous studies indicated that radiation exposure (diagnostic X-ray and CT scan) was not related to cataract in the middle-aged and the elderly.6,7 It is still premature to conclude a causal relationship between stroke and cataract surgery. A large-scaled longitudinal study is needed to ascertain this phenomenon. However, from the patient’s perspective, a stroke survivor with relatively preserved functional status may have a stronger drive to enhance their visual acuity. And, from clinician’s perspective, cataract with visual impairment should be treated more aggressively in order to prevent falls after a stroke. This may be a coincidence following a larger-scale investigation; the attempt to explore the need for stroke survivors should continue.
References
1. Reidy A, Minassian DC, Vafidis G, Joseph J, Farrow S, Wu J, Desai P, Connolly A. Prevalence of serious eye disease and visual impairment in a north London population: Population based, cross sectional study. BMJ. 1998; 316: 1643–1646.
2. Desai P, Minassian DC, Riedy A. National cataract surgery survey 1997–8: a report of the results of the clinical outcomes. Br J Ophthalmol. 1999; 83: 1336–1340.
3. Minassian DC, Reidy A. Visual impairment from cataract in England and Wales: the NHS surgical burden. CE Optometry. 2001; 4: 52–54.
4. Office for National Statistics. Population trends. No. 114, 2003. Available at: http://www.statistics.gov.uk/downloads/theme_population/PT114.pdf. Accessed Nov 2, 2005.
5. Hu FB, Hankinson SE, Stampfer MJ, Manson JE, Colditz GA, Speizer FE, Hennekens CH, Willett WC. Prospective study of cataract extraction and risk of coronary heart disease in women. Am J Epidemiol. 2001; 153: 875–881.
6. Klein BE, Klein RE, Moss SE. Exposure to diagnostic x-rays and incident age-related eye disease. Ophthalmic Epidemiol. 2000; 7: 61–65.[CrossRef][Medline] [Order article via Infotrieve]
7. Hourihan F, Mitchell P, Cumming RG. Possible associations between computed tomography scan and cataract: the Blue Mountains Eye Study. Am J Public Health. 1999; 89: 1864–1866.
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