William W. Cooper and his epidemiological study "On the conical cornea" of 1850.

PURPOSE: We present the life and work of William White Cooper, with a focus on his 1850 study On the conical cornea, the earliest known multicentre epidemiological investigation of keratoconus. We contextualise Cooper's contribution within mid-19th-century ophthalmology, reassessing his findings in light of modern epidemiological knowledge.

METHODS

Historical research was conducted using Gallica (the digital platform of the National Library of France (BnF)) and the historical resources of The Lancet website. The keywords used were 'conical cornea' or 'keratoconus,' which were the most common names for keratoconus.

RESULTS

William White Cooper, a leading Victorian ophthalmic surgeon and later Surgeon-Oculist in Ordinary to Queen Victoria, conducted what appears to be the first epidemiological study of keratoconus, nearly a century before the earliest study typically cited in modern literature. Drawing on data from multiple ophthalmic hospitals across England, Scotland, Ireland, and Macao, Cooper compiled prevalence figures from over 200,000 examined patients between 1814 and 1850. Prevalence rates, recalculated for comparison with modern standards, varied markedly between regions: from 0 in Edinburgh to 254.0 cases per 100,000 in Plymouth, with an overall prevalence of 85.92 per 100,000 for the United Kingdom. The highest prevalence was observed in Macao (324.15 per 100,000), leading Cooper to hypothesise that warmer climates might favor the occurrence of keratoconus. Despite the diagnostic limitations of the period, these values are strikingly close to those reported in parts of modern Europe, underscoring the scale and relevance of his pioneering work.

CONCLUSION

Cooper's 1850 investigation represents the earliest known multicentre epidemiological study of keratoconus, predating modern reports by nearly a century. Despite methodological limitations inherent to the mid-19th century, his findings anticipated contemporary prevalence patterns and introduced the hypothesis of environmental influences on disease occurrence. This work not only enriches the historical record of keratoconus, but also highlights the enduring value of early clinical observation in shaping epidemiological understanding.