Dear Editor

We read with interest the paper by Keenan [ref 1] and colleagues.

We recently studied the 2005/06 Hospital Episode Statistics (HES) data for cataract and have reached similar conclusions. We agree with the authors’ observations that as NHS cataract surgery rates (CSRs) in England have increased significantly in recent years, several questions are now raised. What is the appropriate CSR in a developed market economy? Is the observed geographical variation in CSR in England a marker of increased incidence and requirement for surgery in some ‘high activity’ regions or a marker for overprovision? Conversely, in relation to lower activity regions, are there data set issues from the use of an administrative database such as the HES, or are there genuine clinical differences or variations in the organisational provision of cataract care? Private CSR rates are not considered as HES returns are restricted to NHS care. In our consideration of the most up to date HES returns there are some data problems -due to coding issues- at some hospital Trusts (details on request). Observational studies of cataract surgical practice and population studies of regional prevalence of cataract are now needed. An electronic clinical database -a cataract national dataset- is the most pragmatic method of capturing such data in a timely fashion. Such an e-tool would track changing thresholds for referral for cataract surgery and importantly, consider outcomes for patients at a national level. Such an initiative is technically possible, is strongly supported by the Royal College of Ophthalmologists and now requires government support. With the UK Government’s commitment to developing an electronic patient care record, the deployment of a national electronic cataract dataset would greatly assist in our better understanding of these questions.

Care of NHS cataract patients has improved as a result of better technology and improved access to care, much of which followed the Action on Cataract (AoC) initiative. [2] A recent quality improvement report in relation to NHS cataract care in Scotland has been compelling. [3] However ophthalmologists and commissioners of ophthalmic care should not become complacent. Pressures on eye care services for the future are likely to be significant; as a result of the aging population, lower clinical thresholds for safe treatment for cataract, the introduction of new treatments for patients with age-related maculopathy and other conditions.

Cataract surgery is a highly effective procedure which provides rapid improvement in vision related, as well as non-vision related, outcomes as well as being very cost effective. [4] Benefits to patients are lifelong. The principal causal factor of adult cataract is ageing and demand for services for cataract and other diseases of the aging eye are expected to increase as the UK population ages. The indications for surgery as recommended in the consensus guidelines from the College, simply stated, are: failing vision attributable to lens opacity despite optimal optical correction or ocular co-morbidity and patient willingness and fitness to undergo cataract surgery. The last issue is not problematic as surgery is almost always carried out under day care and local anaesthesia. There is no evidence, that we are aware of, to suggest that patients are having ‘inappropriate’ cataract surgery in the UK

We are aware some Primary Care Trusts (PCTs) are attempting to ‘demand manage’ cataract surgery to certain thresholds of patient visual impairment. Such decisions, if simply based on Snellen visual acuity levels, are likely to disadvantage elderly patients. [5] Attempts to include chronological age as a factor in healthcare policy are likely to be insensitive. [6] Some have suggested that access to surgery could be determined by an assessment of a range of a patient’s visual symptoms and disability, rather than a simple measurement of monocular visual acuity. [7] We support the concept that decision to operate for cataract remains a matter of balanced clinical judgment and consensus reaching with the individual patient. The World Health Organization recommended 3,000 cataract operations per million residents as the minimum to eliminate blindness from cataract and recommended 3,500 per million for established market economics for the year 2000. [8] This latter target is being attained across the English NHS.

References

1. Keenan T, Rosen P, Yeates D, Goldacre M. Time trends and geographical variation in cataract surgery rates in England: study of surgical workload Br J Ophthalmol 2007; EP. doi: 10.1136/bjo.2006.108977

2. Department of Health. Action on cataracts – Good Practice Guidance. NHS Executive. Feb 2000 http://www.dh.gov.uk/assetRoot/04/01/45/14/04014514.pdf

3. Tey A, Grant B, Harbison D, Sutherland S, Kearns P, Sanders R. Redesign and Modernisation of an NHS cataract service (Fife 1997-2004): multifaceted approach. BMJ. 2007; 334: 148-152

4. Walker JG, Anstey KJ, Hennessy MP, Lord SR, von Sanden C. The impact of cataract surgery on visual functioning, vision-related disability and psychological distress: a randomized controlled trial. Clin Experiment Ophthalmol. 34, 734-42 (2006)

5. Westcott, M C, Tuft, S J, Minassian, D C Effect of age on visual outcome following cataract extraction Br J Ophthalmol 2000 84: 1380-1382

6. Beare N, Dandona L. Cataract surgery in very elderly patients BMJ 2001;323:455.

7. Crabtree HL, Hildreth AJ, O'Connell JE, et al. Measuring visual symptoms in British cataract patients: the Cataract Symptom Scale. Br J Ophthalmol 1999;83:519-523

8. World Health Organisation Global Initiative for the Elimination of Avoidable Blindness. Geneva, Switzerland: World Health Organization; 2000. WHO/PBL/97.61 Rev 2.