H18.6 Keratoconus

Name of the Condition

• Keratoconus (ICD Code: H18.6)

Summary

Keratoconus is a progressive eye disorder characterized by the thinning and bulging of the cornea into a cone-like shape. This structural change distorts the cornea's curvature, leading to irregular astigmatism and blurred or distorted vision. The condition typically affects both eyes, though often asymmetrically, and can worsen over time.

Causes

The exact cause of keratoconus is not fully understood, but it is thought to involve a combination of genetic predisposition, environmental factors, and hormonal influences. Some cases may be associated with systemic conditions or eye trauma, though many occur without a clear underlying trigger.

Risk Factors

• Family history of keratoconus
• Chronic eye rubbing or irritation
• Allergic conditions (e.g., atopic dermatitis, asthma)
• Certain connective tissue disorders (e.g., Ehlers-Danlos syndrome)
• Down syndrome

Symptoms

• Blurred or distorted vision
• Increased sensitivity to light and glare
• Frequent changes in eyeglass or contact lens prescriptions
• Difficulty seeing at night or in low light
• Eye strain or headaches

Diagnosis

Diagnosis involves a comprehensive eye examination, including slit-lamp microscopy to assess corneal shape and clarity. Corneal topography is used to map the cornea's curvature and detect irregularities. Pachymetry may measure corneal thickness, and refraction tests evaluate visual acuity changes.

Treatment Options

• Eyeglasses or soft contact lenses for mild cases
• Rigid gas permeable contact lenses for moderate to advanced cases
• Corneal collagen cross-linking to strengthen the cornea
• Intacs (corneal inserts) to reshape the cornea
• Corneal transplant for severe or progressive cases

Prognosis and Follow-Up

Prognosis varies depending on the severity and progression of the condition. Early detection and treatment can slow progression and preserve vision. Regular follow-up with an eye care specialist is essential to monitor changes and adjust treatment as needed. Most patients maintain functional vision with appropriate management.

Complications

• Progressive vision loss
• Corneal scarring
• Increased risk of corneal hydrops (sudden fluid accumulation)
• Difficulty fitting contact lenses
• Reduced quality of life due to visual impairment

Lifestyle & Prevention

• Avoid eye rubbing to prevent further corneal damage
• Use sunglasses to reduce light sensitivity
• Follow proper contact lens hygiene if applicable
• Maintain regular eye exams to monitor progression
• Discuss family history with healthcare providers for early screening

When to Seek Professional Help

Seek immediate medical attention if you experience sudden vision changes, severe eye pain, or increased light sensitivity, as these may indicate complications like corneal hydrops. Regular check-ups are recommended for those with risk factors or a family history.

Tips for Medical Coders

Document the laterality (unilateral or bilateral) and any associated conditions (e.g., atopy, connective tissue disorders) when coding for keratoconus. Ensure clinical notes support the diagnosis and specify the stage or progression if applicable. Use H18.6 for unspecified keratoconus; specify laterality or severity if documented.