Contact Lenses: Selecting RGP Material Properties
In this month’s column — part two in a two-part series — I present specific cases that highlight the considerations of these material properties.
Clinical Scorecard: Contact Lenses: Selecting RGP Material Properties
At a Glance
| Category | Detail |
|---|
| Condition | Rigid Gas Permeable (RGP) Lens Wear |
| Key Mechanisms | Material properties including oxygen permeability, surface chemistry, hardness/modulus, and specific gravity influence lens selection. |
| Target Population | Patients wearing RGP lenses, particularly those experiencing discomfort or visual disturbances. |
| Care Setting | Optometric practice specializing in contact lenses. |
Key Highlights
- Higher-Dk materials optimize oxygen delivery and reduce corneal edema.
- Surface non-wetting can cause lens fogging; switching to lower-Dk materials with lower wetting angles may help.
- Careful material selection can enhance vision, comfort, and ocular health.
Guideline-Based Recommendations
Diagnosis
- Evaluate lens fit, ocular surface health, and material properties.
Management
- Refit patients with higher-Dk materials for better oxygen delivery.
- Address surface non-wetting with appropriate lens coatings and care systems.
Monitoring & Follow-up
- Follow-up on symptoms and lens performance after material changes.
Risks
- Corneal edema and visual disturbances due to inadequate oxygen permeability.
Patient & Prescribing Data
RGP lens wearers experiencing visual disturbances or discomfort.
Use of higher-Dk materials and appropriate lens care systems can resolve issues like corneal edema and lens fogging.
Clinical Best Practices
- Choose high-Dk materials for high-plus lenses to optimize physiology.
- Implement lid hygiene and tear supplements for patients with meibomian gland dysfunction.
References
