Renal coloboma syndrome

Objective: To characterize the ocular features of renal coloboma syndrome. Design: Prospective, observational case series. Participants: Twelve patients referred by the pediatric nephrology clinic a nd the ophthalmic records of five additional patients. Methods. For each patient, age at the time of examination, gender, renal fu nction, and presence of a mutation in the PAX2 gene were noted. All patient s underwent measurement of visual acuity and anterior and posterior segment examination with fundus photography. Goldmann visual fields were tested in four cases. Main Outcome Measures: Visual acuity, optic disc abnormalities, and mutatio n in the PAX2 gene. Results. Mean age was 21.5 years. Renal failure was mild in 6 patients and severe in 11 patients. A mutation in the PAX2 gene was identified in nine p atients, without correlation to the ocular phenotype. Ocular features could be divided into five groups: optic disc dysplasia limited to an unusual pa ttern of retinal vessels without functional consequence; optic disc pit wit h normal visual acuity and blind spot enlargement; large optic disc colobom a; large coloboma of the optic disc and adjacent retina; morning glory anom aly (these last three conditions were accompanied by poor visual acuity). F undus abnormalities were symmetrical in most cases and unrelated to renal s tatus. Conclusions: Ophthalmic and renal characteristics of the renal coloboma syn drome are highly variable. The need for dialysis or renal transplantation c an occur early in life or several years later. A wide range of ocular abnor malities located in the posterior segment can be observed. Mild optic disc dysplasia or pit have no functional consequence and can be underdiagnosed. More severe colobomas or related abnormalities, such as morning glory anoma ly, often lead to poor visual acuity. Molecular biology allows detection of the mutations in the PAX2 gene, but can be negative in approximately 50% o f cases. The observation of an optic disc coloboma or related abnormality s timulates the ophthalmologist to propose simple nephrologic investigations to check for renal hypoplasia, a potentially life-threatening disease. Conv ersely, renal hypoplasia stimulates the nephrologist to ask for a fundus ex amination to confirm the diagnosis and check for complications such as reti nal detachment. Ophthalmology 2001;108:1912-1916 (C) 2001 by the American A cademy of Ophthalmology.