The clinical importance of peripheral refraction as a function of accommodation has become increasingly evident in the last years with special attention given to myopia control. Low order ocular aberrations were measured with a Hartmann–Shack aberrometer in a sample of 28 young emmetropic subjects. A stationary Maltese cross was presented at 2.5 D and 5.0 D of accommodative demand and at 0°, 10° and 20° of eccentricity in the horizontal visual field under two different illumination conditions (white and red light). Wavefront data for a 3 mm pupil diameter were analyzed in terms of the vector components of refraction (M, J0 and J45) and the relative peripheral refractive error (RPRE) was calculated. M was myopic at both accommodative demands and showed a statistically significant myopic increase with red illumination. No significant change in J0 and J45 was found with accommodation nor between illumination conditions. However, J0 increased significantly with eccentricity, exhibiting a nasal-temporal asymmetry. The RPRE was myopic at both accommodation demands and showed a statistically significant hyperopic shift at 20° in the nasal retina. The use of red light introduced statistically and clinically significant changes in M, explained by the variation of the ocular focal length under a higher wavelength illumination, increasing the experimental accommodative demand. These findings may be of relevance for research exploring peripheral refraction under accommodation, as the choice of target illumination is not trivial.
Purpose To assess changes in visual function and optical and tear film quality in computer users. Methods Forty computer workers and 40 controls were evaluated at the beginning and end of a working day. Symptoms were assessed using the Quality of Vision questionnaire (QoV), 5‐item Dry Eye Questionnaire (DEQ‐5) and Symptom Assessment in Dry Eye version II (SANDE II). Tear film quality was evaluated using the Medmont E300 dynamic corneal topography tool to measure the tear film surface quality (TFSQ), TFSQ area and auto tear break‐up time (TBUT). Optical quality was assessed by measuring high, low and total ocular aberrations with a Hartmann–Shack wavefront sensor. Visual performance was assessed by measuring photopic and mesopic visual acuity, photopic and mesopic contrast sensitivity and light disturbance. Results Poorer DEQ‐5, QoV and SANDE II scores were obtained in computer workers at the end of the working day compared with controls (p ≤ 0.02). Computer workers exhibited a higher (worse) TFSQ and TFSQ area at visit 2 compared with visit 1 (p ≤ 0.04), while no significant differences in TBUT (p = 0.19) or ocular aberrations were observed (p ≥ 0.09). Additionally, both light disturbance (p ≤ 0.04) and mesopic and photopic contrast sensitivity worsened at several spatial frequencies (p ≤ 0.04) throughout the working day in computer workers, while visual acuity remained unchanged (p ≥ 0.07). In contrast, control subjects exhibited no decrease in any variable during the day. Conclusions While visual acuity remained unchanged, several aspects of visual function and quality of vision decreased over a day of computer use. These changes were accompanied by greater dry eye symptoms and tear film changes, which are likely to have played a fundamental role. The present study provides insight into new metrics to assess digital eye strain.
Pharmacological dilation of the eye to have a larger pupil diameter may allow a better understanding of the wavefront error changes with accommodation. This work aimed to investigate whether dilation of the pupil with Phenylephrine Hydrochloride (PHCl) application changes the accommodative response and the Zernike coefficient magnitude with accommodative demand when computed to a common pupil size. Sixteen right eyes of healthy young subjects were measured with the commercial Hartmann–Shack aberrometer IRX3 (Imagine Eyes, Orsay, France) 30 min after two drops of 1.0% PHCl were applied. The eye wavefronts for accommodative demands from 0 to 5 D were measured in natural conditions and after pupil dilatation. Statistically significant differences between both conditions were found for the Zernike coefficients C3−1, C31, C40 and C60. Without the effect of PHCl, higher values were found for all higher-order Zernike coefficients (HOA). With increased accommodative response, an increase of C3−1 and a decrease of C31 was observed and the C40 becomes more negative; the change from positive to negative is shown in the accommodative demand of 1.5 D. Conversely, C60 increases with increasing accommodative demand. To conclude, the results demonstrated that the mydriatic effect of PHCl causes changes in the magnitude of HOA when accommodation is stimulated. The trends observed in the different Zernike coefficients were the same reported in previous studies.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.