H18.033 Corneal deposits in metabolic disorders, bilateral

ICD-10-CM H18.033: Corneal deposits in metabolic disorders, bilateral

ICD-10-CM code H18.033 identifies corneal deposits in metabolic disorders affecting both eyes. It falls under the broader category of corneal pigmentations and deposits. Bilateral stromal corneal crystals can be associated with systemic metabolic or storage disorders, and clinical evaluation may involve slit-lamp examination and anterior segment optical coherence tomography. 1 2 3

Plain-language overview

Code H18.033 describes corneal deposits linked to metabolic disorders when the condition is present in both eyes. The clinical finding of bilateral stromal corneal crystals has a broad differential that includes systemic metabolic or storage disorders. 1 3

What this code represents

The code H18.033 represents a diagnosis of corneal deposits in metabolic disorders, bilateral. It is part of the H18.0 category for corneal pigmentations and deposits, which also includes codes for the right eye, left eye, and unspecified eye. 3

Coding details

The H18.033 code provides bilateral laterality specificity for corneal deposits in metabolic disorders. Distinct codes exist for the right eye (H18.031), left eye (H18.032), and unspecified eye (H18.039) within the same ICD-10-CM category. 3

Clinical context

Bilateral diffuse stromal corneal crystals are a distinctive finding that may be observed during a slit-lamp examination. Anterior segment optical coherence tomography can demonstrate hyperreflective deposits distributed throughout the corneal stroma. 1

A rigorous stepwise evaluation may be undertaken to systematically exclude alternative etiologies of bilateral stromal corneal crystals. This differential encompasses hereditary corneal dystrophies, systemic metabolic or storage disorders, hematologic malignancies, and drug-induced keratopathies. 1

Documentation considerations

Documentation for this diagnosis may include slit-lamp examination findings showing crystalline deposits in the corneal stroma. Anterior segment optical coherence tomography images showing multiple hyperreflective lesions distributed throughout the corneal stroma may also be documented. 1

Coverage and utilization context

The H18.033 code is listed in a Centers for Medicare and Medicaid Services billing and coding article for external ocular photography. This article groups H18.031 through H18.033 together under the description of corneal deposits in metabolic disorders. 2

What the sources add

The CMS billing article lists H18.033 within an ocular photography coverage document, while the Unbound Medicine source provides the full code tree hierarchy. The clinical source adds that bilateral stromal corneal crystals require evaluation for multiple systemic etiologies. 1 2 3

Sources

1. Shimmering Clarity: A Rare Case Report of Ocular Cystinosis — pmc.ncbi.nlm.nih.gov; accessed 2026-07-25.
2. Article - Billing and Coding: Ocular Photography - External (A57068) — cms.gov; accessed 2026-07-25.
3. ICD-10-CM 2024 | H18 - Other disorders of cornea — unboundmedicine.com; accessed 2026-07-25.