Ophthalmic & physiological optics : the journal of the British College of Ophthalmic Opticians (Optometrists) · 2022
Influence of rigid lens decentration and rotation on visual image quality in normal and keratoconic eyes.
СтатьяПоддержка исследования: вне правительства СШАПоддержка NIH: внешняя программаНазвание и аннотация: Перевод пока не подготовлен
Обработка статьи · этапы, ошибки и управление
Загрузка состояния…
Ошибки и ограничения
История · было → стало
Состояние обновляется каждые 5 секунд, пока блок открыт. Процент показывается только там, где известен объём работы. Пауза останавливает продолжение этапа; текущий запрос к источнику может завершиться.
Rozema Jos J, Hastings Gareth D, Jiménez-García Marta, Koppen Carina, Applegate Raymond A
Аннотация
PURPOSE: To investigate whether the movement of a rigid sphero-cylindrical contact lens has a greater impact on the visual image quality in highly aberrated eyes than in normal eyes.
METHODS: For 20 normal and 20 keratoconic SyntEyes, a previously determined best sphero-cylindrical rigid lens was permitted to shift by up to ±1 mm from the line of sight and rotate up to ±15°. Each of the 52,111 lens locations sampled was ray-traced to determine the influence on the wavefront aberration. In turn, the logarithm of visual Strehl ratio (log10 [VSX]) was calculated for each aberration structure and was used to estimate the associated changes in logMAR visual acuity. Finally, contour surfaces of two-letter change in visual acuity were plotted in three-dimensional misalignment space, consisting of decentrations in the x and y directions and rotation, and volumes within these surfaces were calculated.
RESULTS: The variations in image quality within the misalignment space were unique to each eye. A two-letter loss was generally reached with smaller misalignments in keratoconic eyes (10.5 ± 4.7° of rotation or 0.27 ± 0.13 mm of shift) than in normal eyes (13.4 ± 1.8° and 0.39 ± 0.15 mm, respectively) due to larger cylindrical errors. For keratoconic eyes, on average, 14.4 ± 14.9% of misalignment space saw VSX values above the lower normal VSX threshold, well below the values of normal eyes of 48.5 ± 18.5%. In some eyes, a specific combination of lens shift and lens rotation away from the line of sight leads to a simulated improvement in visual image quality.
CONCLUSION: Variations in visual image quality due to the misalignment of rigid sphero-cylindrical contact lens corrections are larger for keratoconic eyes than for normal eyes. In some cases, a specific misalignment may improve visual image quality, which could be considered in the design of the next generation of rigid contact lenses.
METHODS: For 20 normal and 20 keratoconic SyntEyes, a previously determined best sphero-cylindrical rigid lens was permitted to shift by up to ±1 mm from the line of sight and rotate up to ±15°. Each of the 52,111 lens locations sampled was ray-traced to determine the influence on the wavefront aberration. In turn, the logarithm of visual Strehl ratio (log10 [VSX]) was calculated for each aberration structure and was used to estimate the associated changes in logMAR visual acuity. Finally, contour surfaces of two-letter change in visual acuity were plotted in three-dimensional misalignment space, consisting of decentrations in the x and y directions and rotation, and volumes within these surfaces were calculated.
RESULTS: The variations in image quality within the misalignment space were unique to each eye. A two-letter loss was generally reached with smaller misalignments in keratoconic eyes (10.5 ± 4.7° of rotation or 0.27 ± 0.13 mm of shift) than in normal eyes (13.4 ± 1.8° and 0.39 ± 0.15 mm, respectively) due to larger cylindrical errors. For keratoconic eyes, on average, 14.4 ± 14.9% of misalignment space saw VSX values above the lower normal VSX threshold, well below the values of normal eyes of 48.5 ± 18.5%. In some eyes, a specific combination of lens shift and lens rotation away from the line of sight leads to a simulated improvement in visual image quality.
CONCLUSION: Variations in visual image quality due to the misalignment of rigid sphero-cylindrical contact lens corrections are larger for keratoconic eyes than for normal eyes. In some cases, a specific misalignment may improve visual image quality, which could be considered in the design of the next generation of rigid contact lenses.