How should initial fit inform soft contact lens prescribing

Area of Science:

• Ophthalmology
• Biomaterials Science

Background:

• Contact lens fit is crucial for wearer comfort and visual acuity.
• Understanding how initial lens fit correlates with end-of-day performance is essential for prescribing practices.

Purpose of the Study:

• To evaluate the relationship between initial contact lens fit and end-of-day fit for both HEMA (hydrogel) and silicone-hydrogel (SiHy) lenses.
• To determine if early indicators of lens fit can predict long-term wearability.

Main Methods:

• Thirty participants were fitted with HEMA and SiHy lenses contralaterally.
• Key fit parameters (centration, lag, movement, recovery speed) were measured at multiple time points up to 8 hours.
• Corneal topography and tear break-up time were assessed pre-wear; comfort was self-reported.

Main Results:

• Comfort and centration were similar between HEMA and SiHy lenses, though comfort decreased over time.
• HEMA lenses exhibited greater movement on blink and lag compared to SiHy lenses.
• Early indicators of lens movement and recovery speed (after 10-20 minutes) predicted 8-hour wear performance for both lens types.

Conclusions:

• Initial assessment of contact lens movement and recovery speed is critical for predicting 8-hour wear.
• Contact lenses demonstrating poor movement or slow recovery after 10-20 minutes of wear should be considered for rejection to ensure optimal patient outcomes.