Keep Your Strabismus Diagnosis Coding From Getting Crossed Up
Learn the difference between hypertropia and hypotropia. Strabismus, commonly known as crossed eyes or misalignment of the eyes, is a complex condition with multiple subtypes, causes, and treatment implications. The condition normally occurs in individuals with poor eye muscle control or who are very nearsighted, according to the American Academy of Ophthalmology, and it most often manifests in children before 3 years old. Any one of 12 extraocular muscles — or a combination of them — could be involved. Because of this variability, ICD-10-CM coding for strabismus requires careful attention to clinical detail and documentation. Coders who master the nuances of the strabismus code set not only ensure accurate claims submission but also contribute to quality reporting, data integrity, and proper patient care tracking. Keep reading to learn about the different forms of strabismus and how to code the conditions. Review These Key Terms An important factor in determining the correct diagnosis code is the direction in which the patient’s eye(s) turn. Look for these terms in the documentation: Don’t miss: If the condition is not constant, it can be classified as intermittent or transient strabismus. Unilateral strabismus describes turning that is always in the same single eye, while alternating strabismus occurs sometimes in one eye and other times in the other. Check Documentation for Specificity ICD-10-CM lists strabismus codes in Chapter 7: Diseases of the Eye and Adnexa (H00-H59). Strabismus codes specifically fall under H49-H52, divided into key categories: Each category drills down into laterality (right, left, bilateral, unspecified) and, in some cases, into finer subclassifications of strabismus type. Important: Correct application of strabismus codes begins with robust clinical documentation. At a minimum, coders should confirm the following details: Without this level of specificity, coders may be forced to assign unspecified codes, which can reduce claim acceptance and limit data accuracy. Break Down the Categories Paralytic strabismus (H49.-): These codes apply when strabismus is due to paralysis of an extraocular muscle, usually from cranial nerve palsy. Coding examples: The documentation should clearly state the cranial nerve affected and laterality to help you select the correct ICD-10-CM code. Esotropia and exotropia (H50.0- and H50.1-): Esotropia involves inward deviation, while exotropia refers to outward deviation. The ICD-10-CM code book breaks these conditions down by: Coding examples: Correct coding here depends on whether the provider has documented if the deviation alternates between eyes or consistently occurs in one eye. Vertical strabismus (H50.2-): Hypertropia (upward deviation) and hypotropia (downward deviation) codes are specified by laterality. Coding examples: The code book also includes other codes to capture combined deviations, such as cyclotropia or dissociated vertical deviation. Intermittent heterotropia (H50.3-): You’ll use these codes when eye misalignment occurs sporadically. Again, documentation must specify the type (eso-, exo-, hyper-). Coding examples: Other disorders of binocular movement (H51.-): These codes apply when the problem is not classic strabismus but still affects ocular alignment or binocular vision, such as: Check These Case Studies Scenario 1: A patient presents with palsy in the abducens nerve of the left eye due to diabetic neuropathy. You would report H49.22 (Sixth [abducent] nerve palsy, left eye). Additionally, you would report E11.49 (Type 2 diabetes mellitus with other diabetic neurological complication) to describe the underlying condition. Scenario 2: Since birth, both of a child’s eyes have turned inward intermittently at different times. You would report H50.05 (Alternating esotropia). Jerry Salley, BA, MFA, Contributing Writer
