Browsing by Author "Bullimore, Mark A."
Now showing 1 - 4 of 4
- Results Per Page
- Sort Options
Item Patient and Parent Perceptions of Myopia Modalities(2022-05) Lattery, Lauren Jayne; Richdale, Kathryn L.; Ritchey, Eric R.; Bullimore, Mark A.Background: Previous studies have reported quality of life (QoL) with soft contact lenses (SCL), orthokeratology (OK), or glasses (GL) in adults and children, but have not compared QoL across all three modalities nor compared adults to children. Studies have compared parent/child QoL responses for visually impaired children, but not in normally sighted children. The aim of this study was to compare QoL of myopic adults and children in GL, SCL, and OK lenses as well as parent/child responses. Methods: Forty-eight adults (aged 18 - 26 years), 49 children (aged 9 - 17 years) and the children’s parents completed Pediatric Refractive Error Profile 2 (PREP2), a validated questionnaire with 7 subscales (symptoms, vision, activities, appearance, peer perception, handling, and overall). Adults and children had to have worn their correction for at least three years. Parents were asked to answer how they thought their child would answer. Scores were compared between age groups, correction groups, and between children and their parents using non-parametric ANOVA, Mann-Whitney U and Wilcoxon Signed Rank tests, as appropriate. Post-hoc pairwise comparisons between correction groups were conducted with Bonferroni adjustment. Results: Average age of adults was 21.9 ± 2.4 and children was 14.1 ± 2.2 years and duration of correction use was 8.2 ± 3.3 for adults and 5.0 ± 2.2 years for children (both p < 0.01). Adult OK wearers were more satisfied with vision (p = 0.04), activities (p < 0.001) and overall (p = 0.03) compared to GL wearers. Children OK wearers reported higher scores for activities than SCL (p = 0.048) and GL wearers (p < 0.001). Parents of contact lens wearers reported higher perceived in activities (OK p < 0.001; SCL p = 0.02), handling (OK p = 0.02; SCL p < 0.001), appearance (SCL p = 0.001), and overall (OK p = 0.001; SCL p < 0.001) subscales than parents of child GL wearers. Conclusion: Activity driven children and adults should consider being fit in OK. Parents’ perceptions did not align with their children’s perceptions of their correction.Item Quantification of Age-Related and per Diopter Accommodative Changes of the Lens and Ciliary Muscle in the Emmetropic Human Eye(Investigative Ophthalmology & Visual Science, 2013-02) Richdale, Kathryn; Sinnott, Loraine T.; Bullimore, Mark A.; Wassenaar, Peter A.; Schmalbrock, Petra; Kao, Chiu-Yen; Patz, Samuel; Mutti, Donald O.; Glasser, Adrian; Zadnik, KarlaPurpose: To calculate age-related and per diopter (D) accommodative changes in crystalline lens and ciliary muscle dimensions in vivo in a single cohort of emmetropic human adults ages 30 to 50 years. Methods: The right eyes of 26 emmetropic adults were examined using ultrasonography, phakometry, anterior segment optical coherence tomography, and high resolution magnetic resonance imaging. Accommodation was measured both subjectively and objectively. Results: In agreement with previous research, older age was linearly correlated with a thicker lens, steeper anterior lens curvature, shallower anterior chamber, and lower lens equivalent refractive index (all P < 0.01). Age was not related to ciliary muscle ring diameter (CMRD) or lens equatorial diameter (LED). With accommodation, lens thickness increased (+0.064 mm/D, P < 0.001), LED decreased (−0.075 mm/D, P < 0.001), CMRD decreased (−0.105 mm/D, P < 0.001), and the ciliary muscle thickened anteriorly (+0.013 to +0.026 mm/D, P < 0.001) and thinned posteriorly (−0.011 to −0.015, P < 0.01). The changes per diopter of accommodation in LED, CMRD, and ciliary muscle thickness were not related to subject age. Conclusions: The per diopter ciliary muscle contraction is age independent, even as total accommodative amplitude declines. Quantifying normal biometric dimensions of the accommodative structures and changes with age and accommodative effort will further the development of new IOLs designed to harness ciliary muscle forces.Item The Effect of Age, Accommodation and Refractive Error on the Adult Human Eye(Optometry and Vision Science, 2016-01) Richdale, Kathryn; Bullimore, Mark A.; Sinnott, Loraine T.; Zadnik, KarlaPurpose: To quantify changes in ocular dimensions associated with age, refractive error, and accommodative response, in vivo, in 30- to 50-year-old human subjects. Methods: The right eyes of 91 adults were examined using ultrasonography, phakometry, keratometry, pachymetry, interferometry, anterior segment optical coherence tomography, and high resolution magnetic resonance imaging. Accommodation was measured subjectively with a push-up test and objectively using open-field autorefraction. Regression analyses were used to assess differences in ocular parameters with age, refractive error and accommodation. Results: With age, crystalline lens thickness increased (0.03 mm/yr), anterior lens curvature steepened (0.11 mm/yr), anterior chamber depth decreased (0.02 mm/y) and lens equivalent refractive index decreased (0.001 /y) (all p < 0.01). With increasing myopia, there were significant increases in axial length (0.37 mm/D), vitreous chamber depth (0.34 mm/D), vitreous chamber height (0.09 mm/D) and ciliary muscle ring diameter (0.10 mm/D) (all p < 0.05). Increasing myopia was also associated with steepening of both the cornea (0.16 mm/D) and anterior lens surface (0.011 mm/D) (both p < 0.04). With accommodation, the ciliary muscle ring diameter decreased (0.08 mm/D), and the muscle thinned posteriorly (0.008 mm/D), allowing the lens to shorten equatorially (0.07 mm/D) and thicken axially (0.06 mm/D) (all p < 0.03). Conclusions: Refractive error is significantly correlated with not only the axial dimensions, but the anterior equatorial dimension of the adult eye. Further testing and development of accommodating intraocular lenses should account for differences in patients’ preoperative refractive error.Item The Effect of Phenylephrine on the Ciliary Muscle and Accommodation(Optometry and Vision Science, 2012-10) Richdale, Kathryn; Bailey, Melissa D.; Sinnott, Loraine T.; Kao, Chiu-Yen; Zadnik, Karla; Bullimore, Mark A.Purpose: To objectively measure changes in the human ciliary muscle dimensions in vivo following instillation of topical phenylephrine, a mydriatic and vasodilating agent. Methods: A cross-sectional study of 25 healthy young adults was conducted. Measurements of pupil size, accommodation, and ciliary muscle thickness were made both before and 30 minutes after instillation of 1% proparacaine and 2.5% phenylephrine. Accommodation was measured three ways: subjectively using a push-up technique and Royal Air Force (RAF) rule, and objectively using both the Grand Seiko autorefractor and PowerRefractor. Images of the temporal ciliary muscle were made using the Visante Anterior Segment Optical Coherence Tomographer (OCT). Ciliary muscle images were objectively analyzed using a computer-based segmentation technique. Results: Amplitude of accommodation with the push-up test was reduced by about 1D with phenylephrine (p < 0.001). Phenylephrine did not change the accommodative response to a 4-D Badal target as measured by either autorefraction or photorefraction (p > 0.30). There was statistically significant thickening of the anterior region and thinning of the posterior region of the ciliary muscle with accommodation (p < 0.001, all locations). Phenylephrine did not affect either baseline ciliary muscle thickness, or the accommodative contraction of the muscle (p > 0.09). Conclusions: Low-dose phenylephrine does not affect ciliary muscle dimensions, ciliary muscle contractility, or accommodative response to a 4 D near target.