H40.1320 Pigmentary glaucoma, left eye, stage unspecified

ICD-10-CM H40.1320: Pigmentary glaucoma, left eye, stage unspecified

ICD-10-CM code H40.1320 identifies pigmentary glaucoma in the left eye when the stage is unspecified. Clinical literature characterizes pigmentary glaucoma as a secondary glaucoma, and public coding references list distinct codes to specify disease severity. A diagnosis code documents a clinical concept but does not independently establish payer coverage. 2 5 6

Plain-language overview

Pigmentary glaucoma is identified in clinical literature as a secondary glaucoma, and the ICD-10-CM code H40.1320 specifically represents this condition in the left eye when the stage is unspecified. 2 5 6

What this code represents

The code H40.1320 corresponds to the diagnosis of pigmentary glaucoma, left eye, stage unspecified, distinguishing it from other left eye severity codes such as H40.1322 for moderate stage and H40.1323 for severe stage. 4 6

Coding details

Public coding references list H40.1320 within a broader category of pigmentary glaucoma codes that designate laterality and severity, including H40.1310 for the right eye and H40.1330 for bilateral cases. 6

Documentation considerations

The supplied coding references list H40.1320 as the designation for pigmentary glaucoma of the left eye with an unspecified stage, existing alongside distinct codes for mild, moderate, severe, and indeterminate stages. 4 6

Clinical context

Clinical literature discusses pigmentary glaucoma management challenges and notes that patients with uncontrolled intraocular pressure and visual field damage progression may undergo surgical interventions such as canaloplasty. 1

Published clinical reviews categorize pigmentary glaucoma as a secondary glaucoma and describe a five-stage clinical gradation for pigment dispersion syndrome that includes a transitional stage converting to pigmentary glaucoma. 2

Coverage and utilization context

The Centers for Medicare and Medicaid Services includes the H40.1320 code in billing and coding articles for procedures such as corneal pachymetry, while clinical literature discusses therapeutic approaches for pigmentary glaucoma including pharmacologic treatment, laser procedures, and surgery. 2 5

What the sources add

Clinical research sources examine surgical outcomes and disease staging for pigmentary glaucoma, whereas government and coding references provide the specific alphanumeric ICD-10-CM structure and descriptions for billing and documentation. 1 2 5 6

The CMS billing article lists H40.1320 alongside moderate and severe left eye stages, while the clinical literature discusses therapeutic strategies that vary by disease stage, providing different operational and clinical contexts. 2 4

Sources

1. Canaloplasty in Pigmentary Glaucoma: Long-Term Outcomes and Proposal of a New Hypothesis on Its Intraocular Pressure Lowering Mechanism — pmc.ncbi.nlm.nih.gov; accessed 2026-07-25.
2. Pigment Dispersion Syndrome and Pigmentary Glaucoma: New Clinical Gradation and Current Therapeutic Strategies — pmc.ncbi.nlm.nih.gov; accessed 2026-07-25.
3. Phecode 365.1 · ExPRSweb — csg.sph.umich.edu; accessed 2026-07-25.
4. Article - Billing and Coding: Micro-Invasive Glaucoma Surgery (MIGS) (A57864) — cms.gov; accessed 2026-07-25.
5. Article - Billing and Coding: Corneal Pachymetry (A56548) — cms.gov; accessed 2026-07-25.
6. ICD-10-CM 2024 | H40.13 - Pigmentary glaucoma — unboundmedicine.com; accessed 2026-07-25.