Clinical Scorecard: Contact Lens Practice Pearls: Don’t Forget to LARS

At a Glance

Key Highlights

• Modern toric soft lenses have improved stability but rotation still occurs and impacts vision correction.
• Each degree of lens misalignment results in approximately 3% to 3.5% loss of cylinder correction.
• Applying the LARS principle precisely reduces chair time, improves patient satisfaction, and enhances practice efficiency.

Guideline-Based Recommendations

Diagnosis

• Assess lens rotation after allowing lenses to settle on the eye.
• Use lens stabilization markings to accurately determine rotation direction and degree.

Management

• If lens rotates left, add the rotation degrees to the refractive axis when ordering lenses.
• If lens rotates right, subtract the rotation degrees from the refractive axis.
• Adjust axis based on consistent rotation; variable rotation suggests lens design issues requiring alternative lens choice.

Monitoring & Follow-up

• Confirm reproducibility of lens rotation and visual clarity at follow-up visits.
• Interpret over-refraction results in the context of observed lens alignment.

Risks

• Assuming perfect lens alignment can lead to extended chair time and patient frustration.
• Ignoring small rotations can cause significant loss of astigmatic correction, especially with higher cylinder powers.

Patient & Prescribing Data

Patients requiring correction of astigmatism with toric soft lenses

Small axis adjustments based on observed lens rotation improve visual outcomes and patient satisfaction; framing adjustments as fine-tuning enhances patient confidence.

Clinical Best Practices

• Do not assume lens stability; always confirm rotation before finalizing prescription.
• Allow sufficient settling time before assessing lens rotation.
• Use the LARS principle systematically to adjust lens axis.
• Educate patients that minor adjustments are intentional and based on precise measurements, not guesswork.
• Consider lens design changes if rotation is inconsistent.

References

• Ma JJ, Tseng SS. Simple method for accurate alignment in toric phakic and aphakic intraocular lens implantation. J Cataract Refract Surg. 2008;34:1631-1636.
• Jackson JM. Toric lenses for today and tomorrow. Contact Lens Spectrum. 2016;31(8):28-32.