Q13.1 Absence of iris

ICD-10-CM Q13.1: Absence of Iris

ICD-10-CM code Q13.1 represents the diagnosis of absence of iris, classified as a congenital abnormality. It is organized under congenital malformations of the anterior segment of the eye. Clinical literature indicates this condition involves partial or full iris hypoplasia and can affect multiple ocular structures. 1 2

Plain-language overview

Code Q13.1 identifies a congenital abnormality characterized by the absence of the iris, which clinical texts define as complete or partial iris hypoplasia visible during a specialized eye examination. 1 2

What this code represents

The diagnosis concept Q13.1 is an active terminology record with the preferred name absence of iris, functioning as a narrower concept under the parent category Q13 for congenital malformations of the anterior segment of the eye. 1

Within the broader range of congenital eye malformations spanning categories Q10 through Q18, Q13.1 is specifically situated alongside other anterior segment conditions such as iris coloboma and congenital corneal opacity. 3

Clinical context

Clinical descriptions of classic aniridia indicate the condition can involve multiple eye structures beyond the iris, potentially including the cornea, lens, fovea, and optic nerve, which may affect visual acuity. 2

Documentation considerations

Clinical literature notes that optical coherence tomography is performed to confirm a diagnosis of aniridia, particularly when iris defects are subtle, and high-frequency ultrasound biomicroscopy is used for infants with opaque corneas. 2

What the sources add

While the terminology record establishes the official code hierarchy and semantic type, the clinical text adds operational context by detailing the specific ocular examinations and variable physical presentations associated with this congenital condition. 1 2

Comparing the sources shows the terminology record limits Q13.1 to a high-level congenital abnormality classification, whereas the clinical text describes complex multi-structure ocular manifestations, and the code list provides specific adjacent diagnostic distinctions. 1 2 3

Sources

1. ICD-10-CM Q13.1 terminology record — National Cancer Institute Enterprise Vocabulary Services; accessed 2026-07-27.
2. Bookshelf — ncbi.nlm.nih.gov; accessed 2026-07-27.
3. Q13.1 - Absence of iris | ICD-10-CM — unboundmedicine.com; accessed 2026-07-27.