Purchase of contact lenses and contact-lenses-related symptoms following the Contact Lenses in Pediatrics (CLIP) Study.

BACKGROUND: The rate and reasons for discontinuation of contact lens wear by young patients are not well known. The Contact Lenses in Pediatrics (CLIP) Study surveyed participants 3 months after the final study visit to determine the percentage of participants who continued to wear contact lenses after study conclusion. The factors associated with continued contact lens wear and differences in behaviors between the children and teens were also determined to provide insights to practitioners who provide refractive correction for patients in those age groups. METHODS: Three months after the CLIP Study completion, participants and parents returned mailed surveys that assessed post-study lens purchase and symptoms related to contact lens wear if contact lenses wear had been continued. Responses were compared between the children and teens using chi(2) or Fisher's exact test. RESULTS: Almost 92% of the surveys were returned. Eighty percent of teens' parents reported purchasing lenses after the study, vs. 63% of the children's parents (p=0.02). Symptoms reported at the last study visit were not significantly associated with future purchase, though there was a trend towards more light sensitivity in those who did not purchase more contact lenses (23.1% vs. 11.8%). Satisfaction with contact lenses was high among both those purchasing additional contact lenses and those who did not. Both children and teens reported similar frequencies of symptoms such as burning, itching or tearing eyes 3 months following study completion. Teens reported having contact-lens-related dry eyes more frequently than children. CONCLUSIONS: A large proportion of children and an even higher proportion of teens continued wearing their lenses 3 months after completing the CLIP Study. Children and teens reported similar contact lens comfort and low frequencies of most symptoms, though teens experienced more dry-eye symptoms. Overall, reports of symptoms in this sample were lower than had been reported in adult populations by other investigators.

A randomized trial of the effect of soft contact lenses on myopia progression in children.

PURPOSE: Soft contact lenses have been reported to increase the progression of myopia. The purpose of this study was to determine whether soft contact lenses affect the progression of myopia in children. METHODS: Children between the ages of 8 and 11 years with -1.00 to -6.00 D myopia and less than 1.00 D astigmatism were randomly assigned to wear soft contact lenses (n = 247) or spectacles (n = 237) for 3 years. Refractive error and corneal curvatures were measured annually by cycloplegic autorefraction, and axial length was measured annually by A-scan ultrasound. Multilevel modeling was used to compare the rate of change of refractive error, corneal curvature, and axial length between spectacle and contact lens wearers. RESULTS: There was a statistically significant interaction between time and treatment for myopia progression (P = 0.002); the average rate of change was 0.06 D per year greater for contact lens wearers than spectacle wearers. After 3 years, the adjusted difference between contact lens wearers and spectacle wearers was not statistically significant (95% confidence interval [CI] = -0.46 to 0.02). There was no difference between the two treatment groups with respect to change in axial length (ANCOVA, P = 0.37) or change in the steepest corneal curvature (ANCOVA, P = 0.72). CONCLUSIONS: These data provide reassurance to eye care practitioners concerned with the phenomenon of "myopic creep." Soft contact lens wear by children does not cause a clinically relevant increase in axial length, corneal curvature, or myopia relative to spectacle lens wear. (ClinicalTrials.gov, NCT00522288.).

Benefits of contact lens wear for children and teens.

PURPOSE: Children are not offered elective contact lenses as a treatment option for refractive error nearly as often as teens are. The purpose of this report was to examine the benefits of contact lens wear for children and teens to determine whether children benefit as much as teens. If they do, children should routinely be offered contact lens wear as a treatment for refractive error. METHODS: Neophyte contact lens wearers were categorized as children (8-12 years of age) or teens (13-17 years of age). They completed the Pediatric Refractive Error Profile (PREP), a pediatric quality-of-life survey for subjects affected only by refractive error, while wearing glasses; then they were fitted with silicone hydrogel contact lenses. One week, 1 month, and 3 months after receiving contact lenses, the subjects completed the same PREP survey. Subjects also completed questions regarding wearing time and satisfaction with contact lenses during specific activities. RESULTS: The study enrolled 169 subjects at three clinical centers. Ninety-three (55%) of the subjects were girls; 78 (46%) were white; and 44 (26%) were Hispanic. After wearing contact lenses for 3 months, the overall PREP score increased from 64.4 for children and 61.8 for teens while wearing glasses to 79.2 for children and 76.5 for teens. The improvement from baseline to 3 months was significant for children and teens (P<0.0001 for both groups), but there was not a significant difference in improvement between children and teens (P>0.05). The areas of most improvement were satisfaction with correction, activities, and appearance. CONCLUSIONS: Contact lenses significantly improved the quality of life, as reported by children and teens using the PREP, and there was not a difference in improvement between children and teens. Contact lens wear dramatically improves how children and teens feel about their appearance and participation in activities, leading to greater satisfaction with their refractive error correction. The improvement in quality of life after contact lens wear indicates that children should be offered contact lenses as a treatment for refractive error as routinely as teens.

Empirical advanced orthokeratology through corneal topography: the University of Houston clinical study.

PURPOSE: Traditionally, orthokeratology has used diagnostic lenses to determine the best fit. The purpose of this study was to determine the efficacy of fitting empirically from corneal topography, without the use of diagnostic lenses. METHODS: Twenty-nine subjects, 18 to 37 years old, with myopia of 1.00 to 4.00 diopters (D) and astigmatism of no more than 1.50 D, were entered into this 6-month study. Corneal topography, scanning slit topography and corneal thickness (Orbscan), confocal microscopy, ultrasound corneal thickness, aberrometry, and biomicroscopy were used to assess corneal changes. Unaided logMAR high-contrast visual acuity, subjective refraction, and questionnaires were used to monitor vision and symptoms. Follow-up visits were scheduled after 1 day, 1 week, 2 weeks, 1 month, 3 months, and 6 months. RESULTS: For 6-month data, unaided logMAR acuity improved from 0.78 +/- 0.26 in the right eye and 0.75 +/- 0.22 in the left eye to 0.06 +/- 0.18 in the right eye and 0.04 +/- 0.16 in the left eye. Myopia decreased from -2.55 +/- 0.87 D in the right eye and -2.47 +/- 0.89 D in the left eye to +0.45 +/- 0.74 D in the right eye and -0.17 +/- 0.69 D in the left eye. Shape factor, using corneal topography, increased from 0.85 +/- 0.13 in the right eye and 0.85 +/- 0.15 in the left eye to 1.28 +/- 0.32 in the right eye and 1.30 +/- 0.29 in the left eye. Both eyes showed a decrease in lower-order aberrations (i.e., defocus) and an increase in higher-order aberrations (i.e., spherical aberrations and coma). CONCLUSIONS: Myopia reduction after 1 week was clinically insignificant from the 1-month results, indicating that the full effect is achieved by 1 week. Neither total nor epithelial corneal thickness varied significantly from baseline measurements.

Contact Lenses in Pediatrics (CLIP) Study: chair time and ocular health.

PURPOSE: Despite several studies that show 8- to 11-year-old children are capable of wearing a various contact lens modalities, parents often report that their eye care practitioner would not fit their child with contact lenses until the child was about 13 years old. We conducted the Contact Lenses in Pediatrics (CLIP) Study to compare contact lens fitting and follow-up between 8- to 12-year-old children and 13- to 17-year-old teenagers. METHODS: At the baseline visit, all subjects underwent a contact lens fitting, including visual acuity, a manifest refraction, autorefraction, and biomicroscopy. Subjects then underwent contact lens insertion and removal training, which consisted of talking about contact lens care as well as inserting and removing a contact lens three times. Subjects returned for follow-up visits at 1 week, 1 month, and 3 months, and visual acuity, contact lens fit assessment, and biomicroscopy were performed. The time of the fitting, the insertion and removal training, and each follow-up visit were measured individually and added for a total chair time. Biomicroscopy examinations were conducted according to a standardized protocol. RESULTS: We enrolled 84 children and 85 teens in the study. Of the 169 subjects, 93 (55.0%) were female, 78 (46.2%) were white, 44 (23.3%) were Hispanic, and 28 (17.6%) were black. The mean (+/- SD) total chair time for children was 110.6 +/- 39.2 min, significantly more than 95.3 +/- 25.2 min for teens (Student's t-test, p = 0.003). Most of the difference was caused by insertion and removal training, which lasted 41.9 +/- 32.0 min for children and 30.3 +/- 20.2 min for teens (Student's t-test, p = 0.01). The presence of conjunctival staining increased from 7.1% of the subjects at baseline to 19.9% of the subjects at 3 months (chi2, p = 0.0006), but the changes were similar between children and teens. No other biomicroscopy signs increased significantly over the 3-month period. CONCLUSIONS: The total chair time for children is approximately 15 min longer than teens, but most of that difference is explained by longer time spent teaching children insertion and removal. Because insertion and removal is generally taught by staff members, the eye care practitioner's time with the patient is similar between children and teens. Furthermore, neither children nor teens experienced problems related to contact lens wear during the study. Eye care practitioners should consider routinely offering contact lenses as a treatment option, even for children 8 years old.

A comparison of tear volume (by tear meniscus height and phenol red thread test) and tear fluid osmolality measures in non-lens wearers and in contact lens wearers.

PURPOSE: Various measures are available to assess the tear film, yet little specific information is available on how they relate to each other. An exploratory study was undertaken to assess three measures and their relationship in non-contact lens wearers and in contact lens wearers. METHODS: Forty-three young subjects (mean age, 25.0 +/- 3.1 years; 19 men and 24 women) without overt ocular disease were recruited and categorized into four similarly sized groups based on contact lens wear (no lens wear, conventional daily wear hydrogels, silicone hydrogel lenses worn on a continuous basis, and gas-permeable contact lenses). Sets of measures, in random order and from both eyes whenever possible, were made using a phenol red thread (PRT) test over 15 seconds (open eye), biomicroscopy to assess tear meniscus height (TMH) from a perpendicular perspective using a 0.05-mm resolution graticule, and a borosilicate glass micropipette used to collect a 5-microL sample of tears for assessment of osmolality by vapor pressure measures. RESULTS: For the complete group of subjects, the TMH data averaged 0.22 +/- 0.07 mm; the average PRT wetting length was 18.0 +/- 6.1 mm; and the tear osmolality averaged 317 +/- 28 mOsm/kg. The intereye differences averaged 0.04 mm for TMH, 3.7 mm for PRT, and 15 mOsm/kg for tear osmolality. There were no detectable sex-related differences in the measures. Compared with the control group (average, 0.25 mm), the TMH data showed a trend to be lower in daily hydrogel (0.21 mm) and silicone hydrogel (0.20 mm) lens wearers, but not in gas-permeable lens wearers (0.24 mm). PRT data was bimodally distributed, with the control group showing slightly higher (average, 21.1 mm) wetting compared with hydrogel lens wearers (16.7 and 17.4 mm) and gas-permeable lens wearers (average, 17.3 mm). Hydrogel (319 mOsm/kg for both groups) and gas-permeable lens wearers (average, 324 mOsm/kg) had higher tear osmolality measures compared with the control group (average, 305 mOsm/kg). Although some of the differences approached statistical significance, any statistical differences were evident only after outliers were removed. However, on pooling all data, there was a statistically significant positive correlation between TMH and open-eye PRT measures (P < 0.001) and an indication of a negative correlation between open-eye PRT and tear osmolality measures. CONCLUSIONS: Even contemporary contact lens wear can have a small but measurable impact on the precorneal tear film osmolality or volume. The changes are internally consistent and, overall, support the idea that the PRT test provides a useful measure of tear meniscus volume.

Can UV radiation-blocking soft contact lenses attenuate UV radiation to safe levels during summer months in the southern United States?

PURPOSE: Peak solar UV radiation (UVR) intensities are typically experienced in summer months. People living in the southern states of the United States, where the UVR frequently exceeds the recommended minimum erythema dose (MED), are at particular risk, especially outdoor workers. The present study analyzed summertime MED readings in Houston, TX, to assess the frequency of intensities regarded as unhealthy. The study also sought to assess whether UV-blocking hydrogel contact lenses provide ocular protection from these high doses. METHODS: Readings, taken at midday using a UVR biometer, were analyzed to assess the potential UVR risk. The spectral response of the meter, modified by the spectral transmission curves of the contact lenses, allowed us to mathematically assess the ocular protection provided. In addition, ambient UVR measurements were taken at midday, using a portable UVR radiometer. The detector was adapted so that a standard diameter hydrogel contact lens could be placed over it to quantify the UV-blocking capabilities of the lens. RESULTS: The MED readings showed that the recommended safety standards were exceeded approximately at local midday 90% of the time. Model calculations and empirical data demonstrated that contact lenses attenuated the MED readings by up to 90%, bringing them well within the recommended Environmental Protection Agency safety standards. CONCLUSION: The efficacy of the model used in this study was verified through direct comparison of the modeled and measured data. UV-blocking hydrogel soft contact lenses reduce the MED to the human eye and therefore limit the lifetime ocular dose. These lenses are highly recommended to prevent the development of UVR-related ocular pathologic conditions.

Opaque contact lens color choices among women of different ethnic groups.

PURPOSE: The opaque contact lens (OCL) market is profitable and expanding. This pilot study sought to identify OCL color preferences among women of three ethnic groups, African American (A), white (W), and Hispanic Americans (H). METHODS: Sixty-three brown-eyed female subjects (19 A; 22 W; 22 H), 18 to 35 years of age, with uncorrected near visual accuity of at least 20/50 were recruited. Each subject was presented with OCLs of three different color pattern designs in each of four colors (blue, green, gray, and hazel). The subjects viewed their appearance in a mirror while wearing each lens. Once all lenses had been observed, the subjects chose their lens color preference. RESULTS: Using the nonparametric Kruskal-Wallis test, an ethnic preference was shown for all but the gray contact lenses. In group A 47.4% rated the hazel lens as their first choice whereas 0% chose the blue lens. In contrast, 45.5% of group C chose the blue lens over the other colors but did not favor the hazel lens, which was their first choice only 4.5% of the time. Group H demonstrated the most diversity in color preference, however, 36.4% chose green as their overall lenscolor preference. CONCLUSIONS: Distinct differences exist in OCL color preferences among the three ethnic groups studied. Improved understanding of this ethnic difference could increase the efficiency of the trial lens process while possibly decreasing inventory costs when one ethnic group dominates a practice patient base.