Amber Gaume

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 (&khgr;2, 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.

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.

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.

Short wavelength-automated perimetry compared with standard achromatic perimetry in autosomal dominant optic atrophy

Background: Autosomal dominant optic atrophy (ADOA, Kjer-type) is a heterogeneous, non-inflammatory degeneration of retinal ganglion cells. The diagnosis of ADOA can be challenging owing to its insidious onset and large variability in phenotypic expression, both within and between individual pedigrees. The earliest literature reports relatively mild centrocaecal scatomas to white targets in ADOA, but extensive and dense peripheral field loss to coloured targets, especially blue, with Bjerrum perimetry. The phrase “inverted peripheral visual fields to coloured targets” has been used to describe this phenomenon. Methods: Humphrey standard achromatic perimetry (SAP) and short wavelength-automated perimetry (SWAP) were carried out on five patients with ADOA. Results: Regardless of wide variations in patient age, visual acuity, disc appearance and colour vision, the SWAP mean deviation (MD) was between 10 and 20 times more depressed than the SAP MD. The actual differences ranged from 9.38 to 13.78 dB. Conclusions: These data are consistent with the original reports suggesting that, early in this disease process, the blue-target deficits are typically peripheral and that this difference between SAP and SWAP perimetry may be a robust indicator of ADOA in both early and late stages of this disease.

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.

OPAQUE CONTACT LENS COLOR CHOICES AMONG WOMEN OF DIFFERENT ETHNIC GROUPS.: Poster # 40

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.