Congenital corneal opacities - a surgical approach to nomenclature and classification.

The classification system of congenital corneal opacification (CCO) may be better considered from a perspective of pathogenesis, surgical intervention, and prognosis. The author feels that CCO is best considered as being primary and secondary. Primary CCO includes corneal dystrophies and choristomas presenting at birth. Secondary CCO may be best considered as cases of kerato-irido-lenticular dysgenesis (KILD) and other secondary causes including infection, iatrogenic, developmental anomalies of the iridotrabecular system or lens or both, and developmental anomalies of the adnexal. The appropriate classification may help determine prognosis of any surgical intervention. Terminology is crucial to furthering our understanding of the formation of the anterior chamber if we are to do so by studying cases of CCO. Peters' anomaly is too imprecise a term to describe cases of CCO. This classification of primary and secondary CCO with its subclassifications cannot be made by clinical examination alone and necessitates other diagnostic assessments. It is time to only accept studies of CCO genotype/phenotype correlation for publication if there is clinical phenotype augmented by anterior segment imaging (OCT or high-frequency ultrasound) or histology or both.