“Pathognomonic” Sign
Documentation of the “pathognomonic’ sign in
achromatopsia was first published in the book:
Photoreceptor Integrity Line As Revealed by Spectral
Domain OCT in Chapter 2: Achromatopsia/Rod
Monochromatism. More recently, another case has
been published in the book: The Retinal Atlas by
Lawrence A. Yannuzzi.
The sharply delineated rectangular hyporeflective space
(Case 1) has also more recently been called the
“bubble”3, as well as an “optical gap”4 or the “A” sign.
It appears that most but not all achromats have the
sign (Case 6). The sign may not be present in very young
achromats, becomes most pronounced at about age 30
and may slowly fade away decades later.3 A similar sign
appears to be present in less than 1% of patients with
SD (Case 7).4 Genetic testing in these cases will
hopefully shed light on the diagnosis.
