Visual performance of myopia control soft contact lenses in non-presbyopic myopes

Purpose: To compare the visual performance of soft contact lenses reported to reduce myopia progression.Methods: In a double-blind, randomized, crossover trial, 30 non-presbyopic myopes wore MiSight™, center-distance Proclear® Multifocal (+2.00 D add), and two prototype lenses for 1 week each. High- and low-contrast visual acuities at 6 m, and 70 and 40 cm; stereopsis at 40 cm; accommodative facility at 33 cm; and horizontal phoria at 3 m and 33 cm were measured after 1 week. Subjective performance was assessed on a numeric rating scale for vision clarity, lack of ghosting, vision stability, haloes, overall vision satisfaction, and ocular comfort. Frequency of eye-strain symptoms and willingness to purchase lenses were also reported with categorical responses. Participants reported wearing times (total and visually acceptable). Linear mixed models and chi-square tests were employed in analysis with level of significance set at 5%. Theoretical optical performance of all lenses was assessed with schematic myopic model eyes (-1.00, -3.00, and -6.00 D) by comparing the slope of the edge spread function (ESF), an indicator for optical performance/resolution and the blur patch size of the line spread function, an indicator for contrast, between the lenses.Results: Proclear Multifocal and MiSight provided the best distance acuities. However, the prototype lenses were rated significantly higher for many subjective variables, and there were no subjective variables where commercial lenses were rated significantly higher than the prototypes. Theoretical optical performance showed steeper slopes of the ESF and greater blur patch sizes of the LSP with commercial lenses, supporting the clinical findings of better visual acuities but reduced subjective performance. Participants wore prototypes longer and reported their vision acceptable for longer each day compared to MiSight. Both prototypes had the highest willingness-to-purchase rate.Conclusions: The prototypes were better tolerated by myopes compared to the commercial soft contact lenses currently used for slowing myopia progression.</p

The Relationship between Visual Acuity, Subjective Vision, and Willingness to Purchase Simultaneous-image Contact Lenses

SIGNIFICANCE: This study reports that subjective vision ratings are better indicators of willingness to purchase simultaneous-image contact lenses than visual acuities and are more valuable in evaluating contact lens performance.PURPOSE: The purpose of this study was to investigate the relationship between visual acuities, subjective vision ratings, and willingness to purchase simultaneous-image contact lenses in presbyopes.METHODS: A retrospective analysis of visual acuities, subjective vision ratings, and willingness to purchase from final visits of two masked, crossover clinical trials of nine prototype and four commercially available simultaneous-image contact lenses in 141 presbyopes was performed. Pearson correlation and area under the receiver operating characteristic curve determined correlations between variables.RESULTS: Most subjective vision ratings were weakly correlated (r &lt; 0.3) with visual acuity at all distances and illumination. Moderate correlations (r, 95% confidence intervals) were found between overall vision satisfaction ratings with visual acuity at 40 (-0.34, -0.28 to -0.40) and 50 cm (-0.33, -0.27 to -0.39), near-vision ratings (daytime) with visual acuity at 40 (-0.48, -0.43 to -0.53) and 50 cm (-0.46; -0.41 to -0.51), and intermediate-vision ratings (daytime) with visual acuity at 40 (-0.39, -0.33 to -0.45) and 50 cm (-0.41, -0.35 to -0.46). Highest discrimination for willingness to purchase was with overall vision satisfaction (area under curve, 0.93) and vision stability (daytime; area under curve, 0.77). Ratings from 4 to 9 for vision satisfaction showed a linear increase in willingness to purchase: a 1-unit increase in vision satisfaction increased willingness to purchase by 20%. Ratings lower than 4 had 0% willingness to purchase. Other subjective ratings showed similar relationships, albeit only 10 to 15% increase in willingness to purchase per unit increase for ratings higher than 4.CONCLUSIONS: Subjective vision ratings are a better indicator of simultaneous-image contact lens performance than visual acuity. Overall vision satisfaction and vision stability are key predictors of willingness to purchase. Subjective vision ratings should be used to evaluate performance rather than visual acuity alone.</p

Effect of phospholipid deposits on adhesion of bacteria to contact lenses

PURPOSE.: Protein and lipid deposits on contact lenses may contribute to clinical complications. This study examined the effect of phospholipids on the adhesion of bacteria to contact lenses. METHODS.: Worn balafilcon A (n = 11) and senofilcon A (n = 11) were collected after daily wear and phospholipids were extracted in chloroform:methanol. The amount of phospholipid was measured by electrospray ionization mass spectrometry. Unworn lenses soaked in phospholipids were exposed to Pseudomonas aeruginosa and Staphylococcus aureus. After 18 h incubation, the numbers of P. aeruginosa or S. aureus that adhered to the lenses were measured. Phospholipid was tested for possible effects on bacterial growth. RESULTS.: A broad range of sphingomyelins (SM) and phosphatidylcholines (PC) were detected from both types of worn lenses. SM (16:0) (m/z 703) and PC (34:2) (m/z 758) were the major phospholipids detected in the lens extracts. Phospholipids did not alter the adhesion of any strain of P. aeruginosa or S. aureus (p > 0.05). Phospholipids (0.1 mg/mL) showed no effect on the growth of P. aeruginosa 6294 or S. aureus 031. CONCLUSIONS.: Phospholipids adsorb/absorb to contact lenses during wear, however, the major types of phospholipids adsorbed to lenses do not alter bacterial adhesion or growth.10 page(s

Extended depth of focus contact lenses vs. two commercial multifocals: Part 2. Visual performance after 1 week of lens wear

Purpose: To compare the visual performance of prototype contact lenses designed via deliberate manipulation of higher-order spherical aberrations to extend-depth-of-focus with two commercial multifocals, after 1 week of lens wear. Methods: In a prospective, participant-masked, cross-over, randomized, 1-week dispensing clinical-trial, 43 presbyopes [age: 42–63 years] each wore AIROPTIX Aqua multifocal (AOMF), ACUVUE OASYS for presbyopia (AOP) and extended-depth-of-focus prototypes (EDOF) appropriate to their add requirements. Measurements comprised high-contrast-visual-acuity (HCVA) at 6 m, 70 cm, 50 cm and 40 cm; low-contrast-visual-acuity (LCVA) and contrast-sensitivity (CS) at 6 m and stereopsis at 40 cm. A self-administered questionnaire on a numeric-rating-scale (1–10) assessed subjective visual performance comprising clarity-of-vision and lack-of-ghosting at various distances during day/night-viewing conditions and overall-vision-satisfaction. Results: EDOF was significantly better than AOMF and AOP for HCVA averaged across distances (p ≤ 0.038); significantly worse than AOMF for LCVA (p = 0.021) and significantly worse than AOMF for CS in medium and high add-groups (p = 0.006). None of these differences were clinically significant (≤2 letters). EDOF was significantly better than AOMF and AOP for mean stereoacuity (36 and 13 seconds-of-arc, respectively: p ≤ 0.05). For clarity-of-vision, EDOF was significantly better than AOP at all distances and AOMF at intermediate and near (p ≤ 0.028). For lack-of-ghosting averaged across distances, EDOF was significantly better than AOP (p < 0.001) but not AOMF (p = 0.186). EDOF was significantly better than AOMF and AOP for overall-vision-satisfaction (p ≤ 0.024). Conclusions: EDOF provides better intermediate and near vision performance than either AOMF or AOP with no difference for distance vision after 1 week of lens wear

Contact lens deposits, adverse responses, and clinical ocular surface parameters

Purpose.: To correlate clinical responses during contact lens wear with the amount of protein or cholesterol extracted from lenses after wear. Methods.: Clinical parameters, including adverse response rates and corneal staining, and symptomatology rating during lens wear were collected from a series of clinical tests comprising four different silicone hydrogel lenses with four different multipurpose solutions. To test for correlates, the amount of total protein or cholesterol extracted from lenses after daily wear were compared statistically to clinical parameters. Results.: The amount of protein (p = 0.008) or cholesterol (p = 0.01) extracted from lenses was higher for those subjects who showed solution-induced corneal staining. Amount of protein extracted was correlated (p < 0.01) with conjunctival staining (R = -0.23), lens front surface wetting (r = 0.14), and lens fit tightness (R = -0.20). These clinical parameters accounted for 48% of lens protein deposition. The amount of cholesterol extracted from lenses was much more weakly associated with clinical variables. Amount of protein or cholesterol extracted from lenses was not associated with the production of any corneal infiltrative or mechanical adverse event during wear and was only very weakly correlated with insertion comfort of lenses. Conclusions.: These results suggest that there may be no physiologically relevant consequence of cholesterol depositing on silicone hydrogel lenses. The amount of protein that deposits onto silicone hydrogel lenses during wear may have more affect on lens performance on-eye. However, the correlations were generally small and may still not indicate any causative relevant physiological response. Further work is required to determine whether there is any direct causative effect to support these correlative findings.6 page(s