Browsing by Author "Tomiyama, Erin S."
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Item Comparison of Toric Orthokeratology and Soft Toric Multifocal Contact Lenses in Managing the Astigmatic Myope(2022-05-11) Tomiyama, Erin S.; Richdale, Kathryn L.; Berntsen, David A.; Marsack, Jason D.; Zadnik, KarlaPurpose: Myopia management is an important intervention to reduce the risk of vision threatening ocular disease. Contact lens treatments for patients with astigmatism include toric orthokeratology (TOK) and soft toric multifocal (STM) lenses. The purpose of this study was to quantify visual performance and the potential for myopia management efficacy with TOK and STM in moderate to high astigmatic patients. Methods: Thirty adults, age 18-39 years, with myopia (plano to -5.00 D) and refractive astigmatism (-1.25 to -3.50 D) were recruited to complete this five-visit crossover study. Subjects wore both TOK and STM lenses in random order for 10±2 days each. After lens wear, visual performance and acceptance was measured with logMAR visual acuity and patient-reported outcome surveys. Peripheral refraction and wavefront aberrometry were measured to determine the lens’ potential impact for myopia management. Results: Adults, who are critical users, preferred STM for cost when forced to choose between the two corrections. Compared to baseline, TOK induced a myopic shift in defocus (M) at all retinal locations except 20 degrees nasal (all p<0.03), but STM only induced a myopic shift at 20 degrees temporal (p<0.03). TOK resulted in more myopic defocus than STM at all locations (all p<0.05) except 20 degrees nasal and temporal in the left eye. Higher-order root mean square wavefront error (5 mm pupil diameter) was significantly increased with TOK (0.64±0.22 µm) and STM (0.48±0.11 µm) from baseline (0.24±0.08 µm, both p < 0.001), and TOK was elevated compared to STM (p = 0.026). Conclusion: TOK induced greater peripheral myopic defocus and higher-order aberrations, which may indicate improved efficacy for myopia management. Adult astigmats preferred the vision with TOK over STM.Item The Role of Corneal Astigmatism When Fitting Orthokeratology Contact Lenses(2019-08) Tomiyama, Erin S.; Richdale, Kathryn L.; Marsack, Jason D.; Berntsen, David A.Purpose: About one-third of children aged 5-17 years old have astigmatism. Children with increasing astigmatism can also have an accompanying increase in myopia via axial elongation. All of the randomized clinical trials to date have excluded patients with more than 1.50 D of astigmatism and there are limited data on the success of orthokeratology in patients with moderate to high astigmatism. The purpose of this thesis was to assess the fit of sphere and toric lenses and quantify the amount of corneal astigmatism corrected, and to determine the effect of peripheral elevation and central corneal astigmatism on toric orthokeratology fitting. Methods: Two different studies were performed. The first was a retrospective analysis on 32 eyes of 16 subjects, half fitted with sphere and half with toric orthokeratology lenses. The post-treatment data after 1-3 months of successful nightly wear were compared to pre-treatment data to analyze the change in corneal astigmatism. The second study was a prospective analysis of the Pentacam tomography of 25 moderate refractive myopic astigmats (1.25 to 3.50 DC), ages 19 to 38 years. A subset of 20 subjects were fitted with Paragon Dual Axis Corneal Refractive Therapy (CRT) lenses that were worn for 10 2 days. Results: Three methods of analysis showed that the decrease in corneal astigmatism for the spherical lens group was 0.10 - 0.22 D, which was approximately 22 - 31% correction, and the toric group was 0.29 - 0.57 D, which was 20 - 36% correction (all p < 0.006). There was a strong correlation between central corneal astigmatism and corneal elevation at the 4, 6, and 8 mm chords (r = 0.979, r = 0.961, r = 0.927, respectively; all p < 0.001). After Dual Axis lens wear, the average decentration of the treatment zone from the pupil center was 0.29 ± 0.23 mm temporal and 0.13 ± 0.26 mm inferior. Conclusion: Toric orthokeratology lenses correct slightly more corneal astigmatism than spherical lenses. Central corneal astigmatism was highly correlated to peripheral elevation and may be a more expedient measure for clinical use when fitting toric orthokeratology lenses. The amount of treatment zone decentration with toric lenses was minimal which may lead to better visual performance.