Ophthalmology and Optometry Coding Alert

Question: If I code for chronic open-angle glaucoma, should I use H40.10X0 or H40.1190?

AAPC Forum Participant

Answer: The ICD-10-CM Index does not offer “chronic” as a choice under Glaucoma > open angle. Instead, the index directs you to codes in the H40.1- (Open-angle glaucoma) section, which is where you will begin your search for the most specific diagnosis code. Here, you will find the following choices:

• H40.10- (Unspecified open-angle glaucoma)
• H40.11- (Primary open-angle glaucoma)
• H40.12- (Low-tension glaucoma)
• H40.13- (Pigmentary glaucoma)
• H40.14- (Capsular glaucoma with pseudoexfoliation of lens)
• H40.15- (Residual stage of open-angle glaucoma)

All of the codes with the exception of H40.10- require 6th characters to specify laterality (1 = right, 2 = left, 3 = bilateral, and 9 = unspecified). All the codes, except H40.15-, also carry the instruction to add a 7th character specifying the stage of the open-angle glaucoma: 0 = stage unspecified, 1 = mild stage, 2 = moderate stage, 3 = severe stage, and 4 = indeterminate stage.

If the chart notes lack specificity regarding the type, stage, and laterality of the glaucoma, you’re left with ICD-10 H40.10X0 (Unspecified open-angle glaucoma, stage unspecified), using the placeholder X for the 6th character as H40.10- has no laterality option for you to choose. Code H40.1190 (Primary open-angle glaucoma, unspecified eye, stage unspecified) would not be correct, as the code specifies primary open-angle glaucoma, which is not supported by the description of the condition as you present it.

This would be a good opportunity to query your provider and discuss ways in which they can better document details of the condition.