Diffuse interstitial keratitis, unspecified eye

This code signifies a widespread inflammation of the corneal stroma (the middle layer of the cornea) without an identified cause or specific laterality. It indicates a non-ulcerative, non-suppurative inflammation that can lead to corneal opacification and vision impairment.

Use this code when documentation indicates interstitial keratitis affecting the entire cornea, but the specific eye (right or left) is not documented. This diagnosis is typically supported by slit-lamp examination findings demonstrating stromal inflammation, often with neovascularization, in the absence of an epithelial defect.

• Avoid using this code if the laterality (right or left eye) is specified in the medical record; instead, choose the more specific H16.321 or H16.322.
• Do not confuse this with other forms of keratitis, such as ulcerative keratitis (H16.0-) or superficial keratitis (H16.2-).
• Always review documentation for any underlying systemic conditions (e.g., syphilis, tuberculosis) that may be the cause, as these would require additional codes.