Jeffrey J. Walline

Corneal reshaping and myopia progression

Background/aims: Anecdotal evidence indicates that corneal reshaping contact lenses may slow myopia progression in children. The purpose of this investigation is to determine whether corneal reshaping contact lenses slow eye growth. Methods: Forty subjects were fitted with corneal reshaping contact lenses. All subjects were 8 to 11 years and had between −0.75 D and −4.00 D myopia with less than 1.00 D astigmatism. Subjects were age-matched to a soft contact lens wearer from another myopia control study. A-scan ultrasound was performed at baseline and annually for 2 years. Results: Twenty-eight of 40 (70%) subjects wore corneal reshaping contact lenses for 2 years. The refractive error and axial length were similar between the two groups at baseline. The corneal reshaping group had an annual rate of change in axial lengths that was significantly less than the soft contact lens wearers (mean difference in annual change = 0.16 mm, p = 0.0004). Vitreous chamber depth experienced similar changes (mean difference in annual change = 0.10 mm, p = 0.006). Conclusion: Results confirm previous reports of slowed eye growth following corneal reshaping contact lens wear.

The Children's Overnight Orthokeratology Investigation (COOKI) Pilot Study

Purpose. Innovations in contact lens materials and designs allow patients to wear contact lenses during sleep to flatten the cornea and temporarily to reduce myopic refractive error and improve unaided visual acuity. We conducted the Children’s Overnight Orthokeratology Investigation (COOKI) pilot study, a case series, to describe the refractive error and visual changes, as well as the slitlamp observations associated with overnight orthokeratology in children, over a period of 6 months. Methods. Twenty-nine 8- to 11-year-old children with myopia between −0.75 and −5.00 D and <−1.50 D corneal toricity were fitted with corneal refractive therapy contact lenses (Paragon Vision Sciences, Mesa, AZ). They were examined within 1 hour of awakening and about 6 hours later at 1 day, 1 week, 2 weeks, 1 month, 3 months, and 6 months after the first night of contact lens wear. At each visit, the logarithm of the minimum angle of resolution (logMAR) visual acuity, manifest refraction, slitlamp examination, and corneal topography were performed. Results. Twenty-three subjects completed the 6-month study. Three subjects decided not to wear contact lenses, two did not achieve acceptable fits, and one moved from the area. At the 6-month afternoon visit, the mean ± SD uncorrected high-contrast visual acuity was +0.08 ± 0.15 logMAR (Snellen equivalent, 20/24), and the mean ± SD spherical equivalent refraction was −0.16 ± 0.66 D. The corneas of three-fifths of the subjects showed mild staining at the morning visit, and one-third of the patients showed mild corneal staining at the afternoon visit. The most common type of stain was central punctate staining. No subjects experienced lasting adverse visual effects from cornea-reshaping contact lens wear during the study period. Conclusions. Overnight cornea-reshaping contact lenses are efficacious for young myopic patients, and no children experienced a serious adverse event during the study.

Multifocal Contact Lens Myopia Control

Purpose Previous studies on soft multifocal contact lens myopia control published in the peer-reviewed literature reported findings of noncommercial contact lenses worn for 1 year or less. This study sought to determine the progression of myopia and axial elongation of children fitted with commercially available distance center soft multifocal contact lenses for 2 years. Methods Eight- to eleven-year-old children with −1.00 D to −6.00 D spherical component and less than 1.00 D astigmatism were fitted with soft multifocal contact lenses with a +2.00 D add (Proclear Multifocal “D”; CooperVision, Fairport, NY). They were age- and gender-matched to participants from a previous study who were fitted with single-vision contact lenses (1 Day Acuvue; Vistakon, Jacksonville, FL). A-scan ultrasound and cycloplegic autorefraction were performed at baseline, after 1 year, and after 2 years. Multilevel modeling was used to compare the rate of change of myopia and axial length between single-vision and soft multifocal contact lens wearers. Results Forty participants were fitted with soft multifocal contact lenses, and 13 did not contribute complete data (5 contributed 1 year of data). The adjusted mean ± standard error spherical equivalent progression of myopia at 2 years was −1.03 ± 0.06 D for the single-vision contact lens wearers and −0.51 ± 0.06 for the soft multifocal contact lens wearers (p < 0.0001). The adjusted mean axial elongation was 0.41 ± 0.03 and 0.29 ± 0.03 for the single-vision and soft multifocal contact lens wearers, respectively (p < 0.0016). Conclusions Soft multifocal contact lens wear resulted in a 50% reduction in the progression of myopia and a 29% reduction in axial elongation during the 2-year treatment period compared to a historical control group. Results from this and other investigations indicate a need for a long-term randomized clinical trial to investigate the potential for soft multifocal contact lens myopia control.

Changes in the Quality of Life of People with Keratoconus

PURPOSE The Collaborative Longitudinal Evaluation of Keratoconus Study (CLEK) previously showed that people with keratoconus report significantly impaired vision-related quality-of-life (V-QoL), as measured on the National Eye Institute Visual Function Questionnaire (NEI-VFQ), similar to that of people who have severe macular degeneration. For this study, we evaluated changes that occurred in V-QoL over seven years of follow-up. DESIGN In this prospective cohort study of 1,166 participants followed up for seven years, we estimated change in V-QoL by projecting the slope of a minimum of three reports on 11 scales of the NEI-VFQ. Correlation with clinical indicators was evaluated, and differences were assessed between those who had clinically significant changes in clinical factors and those who did not. Logistic regression was used to assess factors associated with a decline in 10 points or more in a scale score over seven years. RESULTS All scales showed modest decline except ocular pain and mental health. Baseline factors were not associated with longitudinal change in NEI-VFQ scores. A 10-letter decline in high-contrast binocular visual acuity or a 3.00-diopter increase in corneal curvature were associated with significantly larger declines in V-QoL. In multivariate analysis, these factors also were found to be associated with a 10-point decline in NEI-VFQ scale scores. CONCLUSIONS Keratoconus is associated with significantly impaired V-QoL that continues to decline over time. For a substantial plurality of patients, these declines are significant.

Repeatability and Validity of Astigmatism Measurements

BACKGROUND As more patients inquire about refractive surgical procedures, the measurement of astigmatism prior to surgery becomes more important in assessing refractive outcome. Knowledge of the repeatability of the astigmatism measurement allows one to distinguish a true change in cylinder power from measurement error. METHODS Forty adults with structurally normal eyes and refractive errors were evaluated for the repeatability of astigmatic refractive error measures. Noncycloplegic and cycloplegic measurements of refractive astigmatism were made by retinoscopy, subjective refraction, and autorefraction. All measures were made at 2 visits within 2 weeks by the same examiner. Difference versus mean plots and the 95% limits of agreement of each technique determined the repeatability of a measurement and the agreement between the methods of measurement. RESULTS The most reliable measure of astigmatic refractive error was cycloplegic autorefraction, with 95% limits of agreement of +/- 0.28 D, followed by noncycloplegic autorefraction (+/- 0.35 D) and cycloplegic subjective refraction (+/- 0.44 D). Noncycloplegic retinoscopy was the least reliable astigmatic refractive error measure, with interoccasion 95% limits of agreement of +/- 1.02 D. The most repeatable measurement of cylinder axis was cycloplegic autorefraction; none of the measurements differed by 10 degrees or more. The least repeatable measurement was noncycloplegic retinoscopy; 40% of the measurements differed by 10 degrees or more. CONCLUSION For studies seeking to measure changes in astigmatism in normal eyes, cycloplegic autorefraction is the method of choice.

Randomized Trial of the Effect of Contact Lens Wear on Self-Perception in Children

Purpose. To determine whether contact lens wear affects children’s self-perceptions. Methods. The Adolescent and Child Health Initiative to Encourage Vision Empowerment Study was a randomized, single-masked trial conducted at five clinical centers in the United States. Subjects were 8- to 11-year-old myopic children randomly assigned to wear spectacles (n = 237) or soft contact lenses (n = 247) for 3 years. The primary endpoint was the Self-Perception Profile for Children Global Self-Worth scale. Secondary outcomes included the Physical Appearance, Athletic Competence, Scholastic Competence, Behavioral Conduct, and Social Acceptance Self-Perception Profile for Children scales. Results. Global self-worth was not affected by contact lens wear [analysis of variance (ANOVA), difference = 0.06; 95% CI, −0.004 to 0.117]. Physical appearance (ANOVA, difference = 0.15; 95% CI, 0.07 to 0.22), athletic competence (ANOVA, difference = 0.08; 95% CI, 0.01 to 0.15), and social acceptance (ANOVA, difference = 0.10; 95% CI, 0.03 to 0.17) were all greater for contact lens wearers. Conclusions. Although contact lens wear does not affect global self-perceptions of 8- to 11-year-old myopic children their physical appearance, athletic competence, and social acceptance self-perceptions are likely to improve with contact lens wear. Eye care practitioners should consider the social and visual benefits of contact lens wear when choosing the most appropriate vision correction modality for children as young as 8 years of age.

The contact lens and myopia progression (CLAMP) study: design and baseline data.

Background. Although previous contact lens myopia control studies indicate that rigid contact lenses slow the progression of myopia in children, they have all suffered from limitations that challenge the significance of their results. The Contact Lens and Myopia Progression (CLAMP) Study addresses the limitations of previous studies and attempts to correct them by implementing alternative Study designs. The CLAMP study also measures all the ocular components to examine the potential mechanism of treatment effect. Methods. Eligible children were fitted with rigid gas-permeable contact lenses and enrolled in a run-in period to determine whether they were able to adapt to rigid contact lens wear. Subjects who successfully completed the run-in period were randomly assigned to wear rigid contact lenses or soft contact lenses for the remainder of the 3-year study. The primary outcome measure will be the 3-year change in cycloplegic autorefraction; the secondary outcome measures will include the 3-year change in axial length, peripheral autorefraction, crystalline lens curvatures, corneal curvature and thickness, accommodation, and intraocular pressure, which are being measured annually. Results. We examined 148 eligible subjects who participated in the run-in period. Of the 148 eligible subjects, 116 (78.4%) were able to adapt to rigid contact lens wear and were enrolled in the CLAMP Study. The mean age of the participants at the baseline visit was 10.5 years, and 59.5% were girls. At the randomization visit, the mean (±SD) spherical equivalent refractive error in the right eye was −2.09 ± 0.89 D, the mean central curvature of the right cornea by videokeratography was 44.5 ± 1.3 D, and the mean axial length of the right eye was 24.13 ± 0.71 mm. Conclusions. Four of five children aged 8- to 11-years-old were able to adapt to rigid gas-permeable contact lens wear. The CLAMP Study aims to further clarify the effect of rigid gas-permeable contact lenses on myopia progression in children.

Development of phoria in children

Background. Although the prevalence of phoria in adults is well documented, data are scarce on phoria in children. We present results using modified clinical technique vision screening and data from the Orinda Longitudinal Study of Myopia on a large, population-based sample of nonstrabismic children to document the prevalence of phoria with age. Methods. We collected cross-sectional (N=1495) and longitudinal (N=469) data. Phoria data were collected by cover tests administered by one observer who subjectively classified phoria as orthophoria, esophoria, or exophoria in 2 δ steps. Results. Ninety-seven percent of the children were orthophoric at distance, and there were no significant changes with age. Near phoria showed a more normal distribution, with a 10.8% decrease in the prevalence of exophoria (from 31.8 to 21.0%) and a 5.5% increase in the prevalence of esophoria (from 6.7 to 12.2%) between kindergarten and fifth grade. Conclusions. Children are typically orthophoric or exophoric at near, but convergent shifts occur with age.

The Adolescent and Child Health Initiative to Encourage Vision Empowerment (ACHIEVE) study design and baseline data.

Purpose. The purpose of this study was to describe the baseline characteristics of subjects and methods for a multicenter, randomized clinical trial to compare the effects of contact lens wear and spectacle wear on childrens self-perception. Methods. Eligible subjects are randomly assigned to wear glasses or contact lenses throughout the 3-year study. Self-perceptions are measured 1 month after randomization and every 6 months using the Self-Perception Profile for Children (SPPC). Childrens satisfaction with spectacles and refractive error-related visual quality of life are also measured using surveys developed for the study. Visual acuity, cycloplegic autorefraction, corneal curvature, and axial dimensions are measured annually. Results. Five clinical sites enrolled 484 subjects with a mean (± standard deviation [SD]) age of 10.4 ± 1.1 years. Approximately three-fifths of the subjects are girls, 47.1% of the subjects are white, 21.5% are black, and 21.5% are Hispanic. The mean (± SD) cycloplegic spherical equivalent autorefraction of the right eye is –2.38 ± 1.04 D, and the average (± SD) axial length of the right eye is 24.32 ± 0.77 mm. The average (± SD) Global Self-Worth score on the SPPC is 3.20 ± 0.62 on a scale from one (low perceived competence) to 4 (high perceived competence). The average (± SD) spectacle satisfaction is 59.1 ± 26.6 on a scale from zero (no satisfaction) to 100 (perfect satisfaction). The average refractive error-related quality of life score is 63.5 ± 12.8 on a scale from zero (poor quality of life) to 100 (excellent quality of life). Conclusions. Subjects enrolling in the ACHIEVE Study are an ethnically diverse group of young myopic children. Ocular characteristics of the sample are consistent with data presented in other randomized clinical trials evaluating treatments for myopic children. The data reported here represent the baseline data for a 3-year randomized clinical trial to investigate the effects of contact lens vs. spectacle wear on childrens self-perceptions.

Variables affecting rigid contact lens comfort in the collaborative longitudinal evaluation of keratoconus (CLEK) study.

Purpose. To identify factors associated with rigid contact lens comfort in keratoconus. Methods. Baseline data from the 16 Collaborative Longitudinal Evaluation of Keratoconus (CLEK) Study clinical sites were analyzed for all patients wearing a rigid contact lens in their more severely keratoconic eye (as determined by steep keratometry). Corneal transplant patients, patients who did not wear a rigid contact lens in either eye, patients who did not wear a rigid lens in their worse eye, and patients with missing contact lens comfort data were excluded from the sample. A total of 751 eyes were included. Variables assessed included measures of disease severity, visual acuity through the patients’ habitual rigid contact lenses, contact lens wearing time, the apical fitting relationship of the contact lens, the degree of peripheral clearance, and the presence of corneal scarring and staining. Comfort was measured by asking the patients “In general, how comfortable are your contact lenses?” (1 = very comfortable through 5 = very irritating). Results. Measures of disease severity (steep keratometry and the first definite apical clearance lens) were not associated with lens comfort. There was no difference in self-reported contact lens comfort between patients fitted with apical touch vs. apical clearance. Patients with a peripheral clearance rating of “minimal unacceptable” (more common among patients with milder keratoconus) were approximately half as likely to report good contact lens comfort compared with patients with “average” peripheral clearance (unadjusted odds ratio, 0.39; 95% confidence interval, 0.19 to 0.79). There was no association between contact lens comfort and the other peripheral clearance ratings compared with ratings of average. Conclusions. There does not appear to be an association between decreasing patient-reported rigid lens comfort and increasing disease severity as measured by steep keratometry or first definite apical clearance lens in this sample. The apical fitting relationship (flat vs. steep) does not appear to be associated with patient-reported comfort. Minimal peripheral clearance may contribute to decreased rigid contact lens comfort in keratoconus.