Diagnosis of Incomplete Congenital Stationary Night Blindness in a 2-year-old boy

Congenital stationary night blindness (CSNB) is an umbrella term for a clinically and genetically heterogeneous group of rare inherited retinal diseases (IRDs). Incomplete CSNB (iCSNB) is a rare subtype, with only around 30 detailed clinical case descriptions (excluding reports on female carriers) published so far [1], [2], [3], [4], [5]. First symptoms such as nyctalopia, nystagmus, strabismus and markedly reduced visual acuity (VA) typically occur within the first year of life, with nystagmus usually being the first observable symptom [6].