A type of rod-cone dystrophy—where rod function decline is typically earlier or more pronounced than cone dystrophy—has been identified as a relatively common characteristic of Bardet–Biedl Syndrome.

The fundus exam via ophthalmoscopy is essentially normal early on in cone dystrophy, and definite macular changes usually occur well after visual loss.

Fluorescein angiography (FA) is a useful adjunct in the workup of someone suspected to have cone dystrophy, as it may detect early changes in the retina that are too subtle to be seen by ophthalmoscope.

The most common type of macular lesion seen during ophthalmoscopic examination has a bull's-eye appearance and consists of a doughnut-like zone of atrophic pigment epithelium surrounding a central darker area.

In another, less frequent form of cone dystrophy there is rather diffuse atrophy of the posterior pole with spotty pigment clumping in the macular area.

The relative sparing of rod function in cone dystrophy is evidenced by a normal scotopic ERG, i.e. when the test is carried out in the dark.

In more severe or longer standing cases, the dystrophy involves a greater proportion of rods with resultant subnormal scotopic records.

The beta-carotenoids, lutein and zeaxanthin, have been evidenced to reduce the risk of developing age-related macular degeneration (AMD),[2] and may therefore provide similar benefits[according to whom?]