Tritanomaly

This code describes tritanomaly, a rare form of color vision deficiency characterized by a reduced ability to perceive blue and yellow hues. Individuals with tritanomaly have a functional, but impaired, S-cone (short-wavelength sensitive) photopigment, leading to difficulty distinguishing between blues and greens, and yellows and reds. It is a congenital and typically stable condition.

Use this code when documentation explicitly states a diagnosis of tritanomaly, often identified through specific color vision tests like the Farnsworth D-15 or Ishihara plates (though Ishihara is less sensitive for tritan defects). This code is appropriate for reporting the presence of this specific type of blue-yellow color blindness.

• Differentiate from tritanopia (complete absence of S-cones), which is coded separately.
• Ensure the documentation specifies "tritanomaly" and not a general "color blindness" or "dyschromatopsia" without further detail.
• This code is typically a primary diagnosis when the color vision deficiency is the reason for the encounter, or a secondary diagnosis if it's a co-existing condition.