Change in the age spectrum in strabismus surgery

The proportion of children undergoing strabismus surgery in the total volume of eye muscle operations appears to have decreased. To verify this we analyzed the age of patients who underwent extraocular muscle (EOM) surgery. The data of patients who underwent EOM surgery at the University Eye Hospital Giessen between 1991 and 2019 were reviewed and the numbers of operations in decadal age groups were compared to the German population in the respective period. In addition, the types of strabismus which led to surgery were evaluated. The data pool comprised > 25,000 surgeries involving > 60,000 muscles. In comparison to 1991, in 2019 the proportion of children aged ≤ 10 years decreased from 50.2% to 31.8%, corresponding to a relative decrease of more than one third. The proportion of patients aged > 50 years increased from 6.5% to 22.5%, i.e., by a factor > 3, while the population ≤ 10 years in 2019 was 13% smaller than in 1991 and the population aged > 50 years increased by 37%. The major reason for the decreasing proportion of children was a 53% reduction in surgery for esotropia. We found no apparent changes in the 2nd-5th decades of life. The lower proportion of children undergoing EOM surgery appears to indicate an improvement in vision screening during the past 4 decades. The increasing proportion of older patients may result from better information on potential treatment and increased incidence of acquired strabismus with corresponding complaints. The demographic shift played a secondary role. Due to the population structure in Germany, a further increase in the demand for EOM surgery is to be expected.