ICD-10 Code H33.122 – Parasitic cyst of retina, left eye (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code H33.122 – Parasitic cyst of retina, left eye
What it is
This code identifies a parasitic cyst located in the retina of the left eye. Use it when documentation specifies a retinal cyst caused by a parasite and clearly states the left eye.
Clinical signs
Findings may include reduced vision, floaters, or a visible retinal lesion on eye examination. Clinical features vary; refer to documentation and ophthalmology findings for confirmation.
When to use this code
Use H33.122 when the provider documents a parasitic cyst involving the left retinal tissue. It is appropriate for confirmed laterality and a retinal, not vitreous or choroidal, location. If the note is unclear, check documentation before coding.
Do not use for
Do not use this code for cysts in the right eye, unspecified eye, or nonparasitic retinal cysts. Do not assign it when the lesion is described in another ocular structure.
Coding tip
Verify both the parasitic cause and left-eye laterality in the provider note before assigning H33.122.