Childhood strabismus surgery has plummeted since 1960
medwireNews: Rates of surgery for childhood squint in England have fallen dramatically over the past 50 years, shows a study published in the British Journal of Ophthalmology.
While there are plausible explanations for the overall decline in surgery, there remains a marked discrepancy in rates of strabismus surgery by geographic region, which is of potential concern, say the authors.
"Of the various explanations for geographical variation, the most important single one may be variation in clinical judgment - by general practitioners in referring patients for surgery, and by ophthalmologists - in the thresholds for recommending surgery," write Munazzah Chou (East Surrey Hospital, Redhill, UK) and co-authors.
Chou's team used two sources of patient data to identify hospital admissions for squint surgery among people aged 15 years and younger between 1963/8 and 2010. A total of 519,089 such admissions were identified.
In the first database, annual admission rates fell from 188.8 per 100,000 population in 1968 to 64.1 per 100,000 in 2010. In the second database, admissions fell from 213.2 per 100,000 in 1963 to 61.3 per 100,000 in 2010.
In both regions, the greater part of the fall occurred between 1970 and 1990, note Chou et al. Likely drivers of this decline include a reduction in the incidence and/or severity of the condition; a switch from surgical to nonsurgical treatment; a reduced detection rate following the abolition of school eye tests; and patients, parents, and doctors being less willing to consider surgery for squint.
"Acknowledging the trend of falling rates of squint surgery in children, and understanding their causes, if possible, is important as it will contribute to the planning of service provision nationally," write the researchers. "There are also implications for the training of ophthalmologists, with reducing exposure and fewer opportunities to achieve proficiency in strabismus surgery."
In a second analysis, Chou et al looked at rates of squint surgery across regions of England in the period 1999-2010. They found that rates varied fivefold across the country, from 138.6 per 100,000 in Easington to 28.3 per 100,000 in Kensington and Chelsea.
This discrepancy was highly statistically significant, with a coefficient of variation (CV) of 76, the authors report, which is on a par with the variation in tonsillectomy over the same period.
The reasons for the geographic variation are unclear but may reflect differences in clinical decision-making about the likely risks and benefits of squint surgery, write Chou et al. Notably, no randomized controlled trial has examined the effectiveness or optimal timing of surgical and nonsurgical treatment options for infantile esotropia.
"In the absence of objective evidence, variation between clinicians in their exercise of clinical judgment is likely to become more pronounced," they conclude. "Future work should address whether this scale of variation is clinically warranted."
medwireNews (www.medwirenews.com) is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2013
By Joanna Lyford, Senior medwireNews Reporter