Quality of life in contact lens wear: BLINK study survey results

Paper title: Quality of life after wearing multifocal contact lenses for myopia control for 2 weeks in the BLINK Study

Authors: Ticak, Anita (1); Walline, Jeffrey J (2); Bernsten, David A (1); Mutti, Donald O (2); Jones-Jordan, Lisa A (2); Cardenas, Laura (1); Day, Elizabeth (2); Dougherty, Bradley E (2); The BLINK study group

1. University of Houston College of Optometry, Houston, Texas, USA.

2. The Ohio State University College of Optometry, Columbus, Ohio, USA.

Date: Nov 2023

References: Ticak A, Walline JJ, Berntsen DA, Mutti DO, Jones-Jordan LA, Cardenas L, Day E, Dougherty BE; BLINK Study Group. Quality of life after wearing multifocal contact lenses for myopia control for 2 weeks in the BLINK Study. Ophthalmic Physiol Opt. 2023 Nov;43(6):1491-1499.

[Link to open access paper]

Vision-related quality-of-life surveys can be used within myopia control clinical trials to provide important subjective information on the tolerance, benefit and visual quality of trial treatments.

The Pediatric Refractive Error Profile (PREP) survey was created to quantify the vision-related quality-of-life in children. The survey content was based on data from focus groups of contact lens wearing children aged 8-14yrs and was used to show children subjectively experienced improved vision-related quality-of-life through contact lens wear. It also identified those children more likely to benefit from contact lens use.^1,2

The PREP2 survey aimed to navigate limitations of the original PREP survey, which included poor repeatability and a difficulty in drawing comparisons over longer time periods. The revised study standardised the spread of positive and negatively worded items used and sub-scales relating to Vision, Symptoms, Appearance, Activities, Peer Perceptions, Handling and a separate Overall section were introduced. Rasch analysis was suggested by the authors of the PREP2 study as a way of further analysing the survey data gathered. The Rasch model is a widely accepted method for evaluating and scoring health science surveys.

The purpose of this study was to investigate vision-specific quality of life measures for children wearing single vision and multifocal contact lenses over two weeks by the use of PREP2 survey subscales.

The BLINK study recruited 294 children aged 7 to 11yrs to the 3-yr, randomised, double-masked multi-site trial. Participants were randomised to wear either single vision contact lenses, Biofinity +1.50D add power or +2.50D add power multifocal lens designs (CooperVision).³ Children completed the PREP2 study at 6-monthly intervals over the 3-yr study period. The subscales deemed most appropriate to be used in the survey were Vision, Symptoms, Activities and Overall.

This study reports the findings after two weeks contact lens wear to determine the survey validity. The participants wore contact lenses for an average of 10.3hrs per day, with no difference between the treatment groups.

All subscales demonstrated item reliability and the item fit to the Rasch model for all scales was good. There were no significant differences between the groups for any of the PREP2 subscale scores other than for the Vision subscale. Those wearing +2.50D add powered lenses reported worse visual function than single vision lens wearers, although no differences were found between the +1.50D and single vison wearers or between the two multifocal lenses.

Boys reported more symptoms than girls for the Symptoms subscale and older children reported better scores for the Overall subscale, but there were no significant sex or age differences for other subscales or differences due to refractive error.

The PREP2 survey was found to be statistically valid, suggesting that the responses were an accurate assessment of multifocal contact lens wear in the BLINK study.

The results showed that although the +2.50D add powered multifocal lens gave a statistically significant reduction for Vision subscale scores, the visual quality was clinically similar to that of the +1.50D add powered lens and no relationship was found between contact lens power and the Symptoms, Activities or Overall subscales.

This suggests the higher-powered contact lenses were well-tolerated with minimal effects on vision-related quality-of-life and are a viable option for myopia management in children.

• The minimal reduction in subjective visual quality found after wearing the +2.50D add power lens highlights the visual difference multifocal lens wear provides compared to single vision lenses. Previous studies have reported visual acuity with multifocal lens may differ due to altered contrast sensitivity, higher order aberrations, reading speed and glare.^4-7 These factors may be contributing to the slightly reduced acuity some children experienced. More research is needed to subjectively as well as objectively assess the impact of these factors.
• The use of the PREP2 survey subscales, such as Symptoms, during myopia management treatment product trials may help further our understanding of the overall product performance and acceptability of wear, and would also be a valuable tool in assessing long-term in vision-related quality-of-life.
• The mean age at recruitment to the study was 10 yrs, most children (68.5%) were white and the mean refractive error for all participants was -2.38D. The results may not be directly applicable to children from different age or ethnicity groups or those with higher myopia.

Title: Quality of life after wearing multifocal contact lenses for myopia control for 2 weeks in the BLINK Study

Authors: Anita Ticak, Jeffrey J. Walline, David A. Bernsten, Donald O. Mutti, Lisa A. Jones-Jordan, Laura Cardenas, Elizabeth Day, Bradley E. Dougherty, The BLINK study group

Purpose: To validate Pediatric Refractive Error Profile 2 (PREP2) subscales that can be used to evaluate contact lens wearers and compare vision-specific quality of life measurements between children wearing multifocal and single vision contact lenses for 2 weeks.

Methods: Two hundred and ninety-four myopic children aged 7-11 years (inclusive) were enrolled in the 3-year, double-masked Bifocal Lenses In Nearsighted Kids (BLINK) Study. Participants completed the PREP2 survey after having worn contact lenses for 2 weeks. The Vision, Symptoms, Activities and Overall PREP2 subscales were used to compare participants' subjective assessment while wearing +1.50 or +2.50 D add multifocal or single vision contact lenses. Rasch analysis was used to validate each subscale and to compare participants' subjective assessment of contact lens wear.

Results:  Item fit to the Rasch model was good for all scales, with no individual items having infit mean square statistics outside the recommended range (0.7-1.3). Response category function was acceptable for all subscales, with ordered category thresholds. Measurement precision, assessed by the Rasch person reliability statistic, was less than ideal (≥0.8) for three of the subscales, but met the minimum acceptable standard of 0.5. Scores for the Vision subscale differed by treatment assignment (p = 0.03), indicating that participants with the highest add power reported statistically worse quality of vision, although the difference was only 3.9 units on a scale of 1-100. Girls reported fewer symptoms than boys (p = 0.006), but there were no other differences between boys and girls.

Conclusions: Rasch analysis demonstrates that the PREP2 survey is a valid instrument for assessing refractive error-specific quality of life. These results suggest that vision-related quality of life is not meaningfully affected by 2 weeks of soft multifocal contact lens wear for myopia control.

[Link to open access paper]