Blue Cone Monochromatism.
Level 5 - mechanism / opinion, no new human data
Narrative review without systematic search methodology or original data
PubMed 40736816 · doi:10.1007/978-3-031-72230-1_14
What was done
This is a narrative review describing the epidemiology, clinical presentation, pathophysiology, and diagnostic differentiation of blue cone monochromatism (BCM) from rod monochromatism (achromatopsia).
What was found
The abstract reports an estimated prevalence of 1 in 100,000 individuals, predominantly affecting males through X-linked recessive inheritance. Patients present in infancy with visual acuity between 20/80 and 20/200, pendular nystagmus, photophobia, myopia, and color vision restricted to the blue light spectrum due to absence of L- and M-cone function with preserved S-cone and rod function. Differential features distinguishing it from achromatopsia include better visual acuity, preserved tritan discrimination, myopia (compared to hyperopia in achromatopsia), and distinct electrophysiological and psychophysical (Berson plates) test results.
Why it matters
This synthesis outlines the critical clinical and psychophysical distinctions required to accurately diagnose blue cone monochromatism and differentiate it from complete achromatopsia.
Limits
As a narrative review, it presents no original clinical data, sample size, or systematic search methodology. Quantitative diagnostic thresholds and the incidence of progressive central retinal atrophy are not detailed in the abstract.