scholarly journals Influence of Lenslet Configuration on Short-Term Visual Performance in Myopia Control Spectacle Lenses

2021 ◽  
Vol 15 ◽  
Author(s):  
Xue Li ◽  
Chenglu Ding ◽  
Yuhao Li ◽  
Ee Woon Lim ◽  
Yi Gao ◽  
...  
Keyword(s):  
Contrast Sensitivity ◽  
Random Order ◽  
Optical Quality ◽  
Visual Performance ◽  
Modulation Transfer ◽  
Short Term ◽  
Spatial Frequencies ◽  
Full Correction ◽  
The Right ◽  
Myopia Control

Purpose: This study aimed to evaluate short-term visual performance and optical quality of three different lenslet configurations on myopia control spectacle lenses.Materials and Methods: This study utilized a cross-over design. Distance visual acuity (VA) was measured in 50 myopic children; contrast sensitivity (CS) was measured in 36 myopic children. For each test, four spectacle lenses were evaluated in a random order: single-vision lens (SVL), lens with concentric rings of highly aspherical lenslets (HAL), lens with concentric rings of slightly aspherical lenslets (SAL), and lens with honeycomb configuration of spherical lenslets (HC). The modulation transfer function (MTF) and MTF area (MTFa) were used to determine optical quality. All tests were performed monocularly on the right eye with full correction.Results: HAL and SAL had larger MTFa than HC. VA in lenses with lenslets was significantly reduced compared to SVL (all p < 0.01). The reduction in VA was worse with HC than with SAL (p = 0.02) and HAL (p = 0.03); no effect of lenslet asphericity was found (p > 0.05). VA changes induced by lenslets showed no correlation with spherical equivalent refraction (all p > 0.05) and were weakly positively associated with age for SAL (r = 0.36, p = 0.01) and HC (r = 0.31, p = 0.03), but not for HAL (p = 0.30). The area under the log contrast sensitivity function (AULCSF) decreased with HAL and HC (all p < 0.001) in all illumination levels, and AULCSF with HAL was higher than that with HC in a photopic condition (1.17 ± 0.10 vs. 1.10 ± 0.13, p = 0.0004). The presence of lenslets did not affect CS at 3 cycles per degree (cpd) (p = 0.80). At 6 to 18 cpd, CS was significantly reduced by HAL and HC (all p < 0.05), but not SAL (p > 0.05) compared to SVL. At high spatial frequencies (>12 cpd) both SAL and HAL reduced CS significantly less than HC (all p < 0.01).Conclusion: Short-term visual performance was minimally impaired by looking through the lenslet structure of myopia control spectacle lenses. Concentric rings with aspherical lenslets had a significantly lower impact on both VA and CS than honeycomb configuration with spherical lenslets.

scholarly journals Short-Term Changes in Light Distortion in Orthokeratology Subjects

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Elena Santolaria Sanz ◽  
Alejandro Cerviño ◽  
Antonio Queiros ◽  
Cesar Villa-Collar ◽  
Daniela Lopes-Ferreira ◽  
...  
Keyword(s):  
Contrast Sensitivity ◽  
Optical Quality ◽  
Sensitivity Function ◽  
Spherical Equivalent ◽  
Short Term ◽  
High Frequencies ◽  
Corneal Aberrations ◽  
Quality Degradation ◽  
Spatial Frequencies ◽  
Distortion Parameters

Purpose. Quantifying adaptation to light distortion of subjects undergoing orthokeratology (OK) for myopia during the first month of treatment.Methods. Twenty-nine healthy volunteers (age: 22.34 ± 8.08 years) with mean spherical equivalent refractive error −2.10 ± 0.93D were evaluated at baseline and days 1, 7, 15, and 30 of OK treatment. Light distortion was determined using an experimental prototype. Corneal aberrations were derived from corneal topography for different pupil sizes. Contrast sensitivity function (CSF) was analyzed for frequencies of 1.50, 2.12, 3.00, 4.24, 6.00, 8.49, 12.00, 16.97, and 24.00 cpd under photopic conditions.Results. Average monocular values of all light distortion parameters measured increased significantly on day 1, returning to baseline after 1 week (P<0.05in all cases). Spherical-like aberration stabilized on day 7 for all pupil diameters, while coma-like for smaller pupils only. CSF was significantly reduced on day 1 for all spatial frequencies except for 1.5 cpd, returning to baseline afterwards. Significant correlation was found between light distortion and contrast sensitivity for middle and high frequencies (P<0.05) after 15 days.Conclusion. Despite consistently increased levels of corneal aberrations, light distortion tends to return to baseline after one week of treatment, suggesting that neural adaptation is capable of overcoming optical quality degradation.

scholarly journals Comparison of the visual performance of iris-fixated phakic lens and implantable collamer lens to correct high myopia

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Xiao-ling Jiao ◽  
Jun Li ◽  
Zhe Yu ◽  
Ping-hui Wei ◽  
Hui Song
Keyword(s):  
Visual Acuity ◽  
High Myopia ◽  
Optical Quality ◽  
Visual Performance ◽  
Quality Analysis ◽  
Modulation Transfer ◽  
Implantable Collamer Lens ◽  
Good Visual Acuity ◽  
Significant Difference ◽  
Group 6

Abstract Background To compare visual performance between the iris-fixated phakic intraocular len (pIOL) and implantable collamer len (ICL) to correct high myopia. Methods Twenty-four eyes underwent iris-fixated pIOL implantation and 24 eyes underwent ICL implantation. At the 6-month follow-up, the best-corrected visual acuity (BCVA) and uncorrected distance visual acuity (UDVA) were compared between the iris-fixated pIOL and ICL groups. The objective scatter index (OSI), modulation transfer function (MTF) cutoff, and ocular aberrations were performed to evaluate postoperative visual quality between the two groups. Results No significant difference was found in UDVA, BCVA, and spherical equivalent between the iris-fixated pIOL and ICL groups (P > 0.05). Six months after surgery, the following values were significantly higher in the ICL group than in the iris-fixated pIOL group: MTF cutoff, strehl ratio and optical quality analysis system values at contrasts of 9 %, 20 %, and 100 % (P < 0.01). The OSI in the iris-fixated pIOL group was higher than in the ICL group 6 months after surgery (P < 0.01). All high-order aberrations were slightly more severe in the iris-fixated pIOL group than in the ICL group 6 months after surgery, although only trefoil (P = 0.023) differed significantly in this regard. Conclusions Both iris-fixated lenses and ICLs can provide good visual acuity. ICLs confer better visual performance in MTF-associated parameters and induce less intraocular light scattering than iris-fixated pIOLs.

scholarly journals Comparison of visual and optical quality of monofocal versus multifocal intraocular lenses

2019 ◽  
Vol 30 (2) ◽  
pp. 299-306 ◽  
Author(s):  
Irene Altemir-Gomez ◽  
Maria S Millan ◽  
Fidel Vega ◽  
Francisco Bartol-Puyal ◽  
Galadriel Gimenez-Calvo ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Transfer Function ◽  
Contrast Sensitivity ◽  
Intraocular Lens ◽  
Modulation Transfer Function ◽  
Area Under The Curve ◽  
Optical Quality ◽  
Intraocular Lenses ◽  
Modulation Transfer ◽  
Multifocal Intraocular Lenses

Objective: To compare visual quality in patients implanted with Tecnis® monofocal (ZCB00) and multifocal (ZMB00) intraocular lenses taking into account their optical quality measured in vitro with an eye model. Methods: In total, 122 patients participated in this study: 44 implanted with monofocal and 78 with multifocal intraocular lenses. Measurements of visual acuity and contrast sensitivity were performed. The optical quality of the intraocular lenses was evaluated in three image planes (distance, intermediate and near) using an eye model on a test bench. The metric considered was the area under the curve of the modulation transfer function. Results: Optical quality at the far focus of the monofocal intraocular lens (area under the curve of the modulation transfer function = 66.97) was considerably better than that with the multifocal lens (area under the curve of the modulation transfer function = 32.54). However, no significant differences were observed between groups at the distance-corrected visual acuity. Distance-corrected near vision was better in the multifocal (0.15 ± 0.20 logMAR) than that in the monofocal group (0.43 ± 0.21 logMAR, p < 0.001), which correlated with the better optical quality at near reached by the multifocal intraocular lens (area under the curve of the modulation transfer function = 29.11) in comparison with the monofocal intraocular lens (area under the curve of the modulation transfer function = 5.0). In intermediate vision, visual acuity was 0.28 ± 0.16 logMAR (multifocal) and 0.36 ± 0.14 logMAR (monofocal) with p = 0.014, also in good agreement with the values measured in the optical quality (area under the curve of the modulation transfer function = 10.69 (multifocal) and 8.86 (monofocal)). The contrast sensitivity was similar in almost all frequencies. Pelli–Robson was slightly better in the monofocal (1.73) than in the multifocal group (1.64; p = 0.023). Conclusion: Patients implanted with multifocal ZMB00 achieved a distance visual acuity similar to those implanted with monofocal ZCB00, but showed significantly better intermediate and near visual acuity. A correlation was found between intraocular lenses’ optical quality and patients’ visual acuity. Contrast sensitivity was very similar between the multifocal and monofocal groups.

Comparison of short‐term light disturbance, optical and visual performance outcomes between a myopia control contact lens and a single‐vision contact lens

2020 ◽  
Vol 40 (6) ◽  
pp. 718-727 ◽  
Author(s):  
José Vicente García‐Marqués ◽  
Rute Juliana Macedo‐De‐Araújo ◽  
Alejandro Cerviño ◽  
Santiago García‐Lázaro ◽  
Colm McAlinden ◽  
...  
Keyword(s):  
Contact Lens ◽  
Performance Outcomes ◽  
Visual Performance ◽  
Short Term ◽  
Single Vision ◽  
Myopia Control

scholarly journals Effects of screen-based retinal light stimulation measured with a novel contrast sensitivity test

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0254877
Author(s):  
Antonia Neumann ◽  
Katharina Breher ◽  
Siegfried Wahl
Keyword(s):  
Optic Nerve ◽  
Contrast Sensitivity ◽  
Optic Nerve Head ◽  
Critical Role ◽  
Spectral Composition ◽  
Visual Performance ◽  
Light Stimulation ◽  
Full Field ◽  
Polychromatic Light ◽  
Myopia Control

Myopia is increasing worldwide hence it exists a pressing demand to find effective myopia control strategies. Previous studies have shown that light, spectral composition, spatial frequencies, and contrasts play a critical role in refractive development. The effects of light on multiple retinal processes include growth regulation, but also visual performance and perception. Changes in subjective visual performance can be examined by contrast sensitivity (CS). This study was conducted to investigate whether retinal light stimulation of different wavelength ranges is able to elicit changes in CS and, therefore, may be used for myopia control purposes. In total, 30 right eyes were stimulated with the light of different wavelength ranges, including dominant wavelengths of ∼480 nm, ∼530 nm, ∼630 nm and polychromatic light via a commercial liquid crystal display (LCD) screen. Stimulation was performed screen full-field and on the optic nerve head only. CS was measured before any stimulation and after each stimulation condition using a novel and time-efficient CS test. Post-stimulation CS changes were analyzed by ANOVA regarding the influencing factors spatial frequency, stimulation wavelength and stimulation location. A priorly conducted verification study on a subset of five participants compared the newly developed CS test to a validated CS test. The novel CS test exhibited good reliability of 0.94 logCS and repeatability of 0.13 logCS with a duration of 92 sec ± 17 sec. No clinically critical change between pre- and post-stimulation CS was detected (all p>0.05). However, the results showed that post-stimulation CS differed significantly at 18 cpd after stimulation with polychromatic light from short-wavelength light (p<0.0001). Location of illumination (screen full-field vs. optic nerve head) or any interactions with other factors did not reveal significant influences (all p>0.05). To summarize, a novel CS test measures the relationship between retinal light stimulation and CS. However, using retinal illumination via LCD screens to increase CS is inconclusive.

scholarly journals The effect of tinted spectacle lenses on contrast sensitivity and colour vision

2013 ◽  
Vol 72 (2) ◽  
Author(s):  
M. Shaik ◽  
P. D. Majola ◽  
L. M. Nkgare ◽  
N. B. Nene ◽  
C. Singh ◽  
...  
Keyword(s):  
Social Science ◽  
Contrast Sensitivity ◽  
Colour Vision ◽  
Light Transmission ◽  
Visual Performance ◽  
Dry Eyes ◽  
Spatial Frequencies ◽  
Kwazulu Natal ◽  
Harmful Radiation ◽  
The University

Aim: Spectacle wearers often prefer tintedlenses to clear or non-tinted lenses for their protection against harmful radiation, improved cos-mesis, enhancement of visual performance and effects on colour vision. Among the available tinted lenses on the market blue, brown and grey tinted spectacle lenses are popular with varying gradesranging from A to D. Due to reduced transmission of light through such lenses, the optical system of the eyes and the environmental vision may be temporarily altered. Colour vision (CV) and con-trast sensitivity (CS) are important aspects of this altered visual world. This study investigated the effect of spectacle lenses of varying grades of tint on CS and CV.Method: The study adopted a pre- and postest research design and a sample of 90 participants were selected from the University of KwaZulu-Natal student population using convenience sam-ling. Each participant was screened for patholgy, dyschromatopsia, severe dry eyes (TBUT<5 seconds), and the presence of any more than low metropia. Thereafter each successful participant was tested for CS and CV with their habitual precription and then tested randomly with a white clear) lens (placebo) and tinted (blue, brown, and grey) spectacle lenses made of CR39 material each having grades A, B and C over their habitual state. Light transmission was 85%, 75%, and 50% for grades A, B, and C respectively. The Functional Acuity Contrast Test (FACT) chart and American Optical Hardy, Rand, and Rittler (AO HRR) were used for the assessment of CS and CV respectively.Results: The data was analysed using the Statistical Package of Social Science (SPSS) version18. Compared to the habitual state, contrast sensitivity was enhanced with all the tinted lensesThe greater enhancement was for low spatial frequencies (LSF) and least for high spatial frequencies (HSF). With all tints Grade C had the least enhancement for very HSF. Many subjects showed no change in CV with any of the lensesused. The grey tint showed greater enhancement of CV as the density increases. Blue and brown tints showed a similar trend with grade B enhancing CV the most while grade C resulted in theleast reduction of CV.Conclusion: Grade A, B, and C of blue, brown and grey tinted spectacle lenses do not alter colour vision significantly but for the selected levels of transmission of the tints used, contrast sensitivity can be improved to some extent. 

scholarly journals Comparison of Optical Quality and Distinct Macular Thickness in Femtosecond Laser-Assisted versus Phacoemulsification Cataract Surgery

2019 ◽  
Author(s):  
Yong Wang ◽  
Jinling Zhang ◽  
Miaomiao Qin ◽  
Jianguo Miao ◽  
Wei Chen ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Femtosecond Laser ◽  
Cataract Surgery ◽  
Optical Quality ◽  
Macular Thickness ◽  
Modulation Transfer ◽  
Distance Visual Acuity ◽  
Spatial Frequencies ◽  
Post Operation ◽  
Phacoemulsification Cataract Surgery

Abstract Background: Optical quality and macular thickness changing optical quality is rarely reported after femtosecond laser-assisted cataract surgery. In current research, we evaluated optical quality recovery and distinct macular thicknesschanges after FLACS and phacoemulsification cataract surgery (PCS). Methods: A total of 100 cataract patients (100 eyes) were included (50 eyes for the FLACS group and 50 eyes for the PCS group). Modulation transfer function (MTF), point spread function (PSF) and dysfunctional lens index (DLI) were measured by a ray-tracing aberrometer (iTrace). Uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA) were also assessed pre-operation and 1 month after surgery. The MTF values at spatial frequencies of 5, 10, 15, 20, 25 and 30 cycles/degree (c/d) were selected. We used optical coherence tomography (OCT) to assess the macular thickness of different regions pre-operatively and1month after the surgery. Results: In PCS group, we found the statistically significant differences between pre-operation and post-operation in DLI ( p <0.0001), PSF(strehl ratio, SR) ( p= 0.027) and MTF ( p =0.028), but not intraocular pressure (IOP) ( p =0.857). The differences between pre-operation and post-operation for DLI ( p =0.031), SR ( p =0.01) and IOP ( p =0.03), but not MTF ( p =0.128) were also found in FLACS group. The differences were statistically significant when the spatial frequencies were at 5, 10 and 25 ( p =0.013, 0.031 and 0.048) between pre-operation and post-operation in PCS group but not FLACS group. In PCS group, we found the differences between pre-operation and post-operation in nasal inter macular ring thickness (NIMRT) ( p =0.03), foveal volume (FV) ( p =0.034) and average retinal thickness (ART) ( p =0.025) but not FLACS group. Conclusion: FLACSis safe that did not cause significant increase of macular thickness in current study. However, it also cannot produce better optical quality. In contrast,PCS can produce macular thickness changes, but better optical quality recovery. The slightly retinal change may not affect optical quality.

scholarly journals Comparative Analysis of Visual Performance and Astigmatism Tolerance with Monofocal, Bifocal, and Extended Depth-of-Focus Intraocular Lenses Targeting Slight Myopia

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Jie Xu ◽  
Tianyu Zheng ◽  
Yi Lu
Keyword(s):  
Contrast Sensitivity ◽  
Significant Negative Correlation ◽  
Optical Quality ◽  
Corneal Astigmatism ◽  
Intraocular Lenses ◽  
Visual Performance ◽  
Depth Of Focus ◽  
Visual Outcomes ◽  
Extended Depth Of Focus ◽  
Visual Function Questionnaire

Purpose. To compare the visual performance and astigmatism tolerance of 3 intraocular lens (IOL) groups: monofocal, bifocal, and extended depth-of-focus (EDOF) IOLs targeting slight myopia. Methods. Overall, there were 60 cataract surgery eyes from 60 patients with implantation of a monofocal, bifocal, or EDOF IOL (20 eyes in each IOL group). The EDOF IOLs targeted slight myopia (−0.25 D to −0.75 D). Intragroup comparison of visual acuity, defocus curve, objective optical quality, contrast sensitivity, visual function questionnaire scores, patients’ overall satisfaction, and the astigmatism tolerance was performed 3 months after surgery. Results. The EDOF group provided equivalently excellent distance visual outcomes (0.06 ± 0.12) as the monofocal (0.06 ± 0.09) and bifocal (0.03 ± 0.09) groups P = 0.554 , better intermediate vision than the other 2 groups P < 0.05 , and similarly satisfactory near visual outcomes (0.23 ± 0.16 at 20 cm, and 0.17 ± 0.14 at 33 cm) as the bifocal group (0.28 ± 0.14 at 20 cm and 0.08 ± 0.10 at 33 cm) P > 0.05 . The contrast sensitivity of EDOF IOL was slightly decreased compared to that of monofocal IOL, but it was better than that of bifocal IOL. The EDOF group showed significantly higher satisfaction than the bifocal group did when preoperative corneal astigmatism was 0.75 D or greater P = 0.009 . A significant negative correlation between the corneal astigmatism and patient satisfaction was observed in only the bifocal group. Conclusions. The EDOF IOLs targeting slight myopia offered satisfactory visual outcomes at an extended range from far to near distances. The EDOF and monofocal IOLs showed a better tolerance to astigmatism than did the bifocal IOL.

scholarly journals Contrast Sensitivity of Cats and Humans in Scotopic and Mesopic Conditions

2009 ◽  
Vol 102 (2) ◽  
pp. 831-840 ◽  
Author(s):  
Incheol Kang ◽  
Rachel E. Reem ◽  
Amy L. Kaczmarowski ◽  
Joseph G. Malpeli
Keyword(s):  
Contrast Sensitivity ◽  
Temporal Frequency ◽  
Companion Paper ◽  
Behavioral Data ◽  
Scotopic Vision ◽  
Visual Systems ◽  
Spatial Frequencies ◽  
Dim Light ◽  
The Right ◽  
Central Fixation

Human contrast sensitivity in low scotopic conditions is regulated according to the deVries–Rose law. Previous cat behavioral data, as well as cat and mice electrophysiological data, have not confirmed this relationship. To resolve this discrepancy at the behavioral level, we compared sensitivity in dim light for cats and humans in parallel experiments using the same visual stimuli and similar behavioral paradigms. Both species had to detect Gabor functions (SD = 1.5°, spatial frequencies from 0 to 4 cpd, temporal frequency 4 Hz) presented 8° to the right or left of a central fixation point over an 8 log-unit range of adaptation levels spanning scotopic vision and extending well into the mesopic range. Cats had 0.74 log unit greater absolute sensitivity than that of humans for spatial frequencies ≤1/8 cpd. Cats had better contrast sensitivity overall for spatial frequencies <1/2 cpd, whereas humans were more sensitive for spatial frequencies above this. However, most of the cat's sensitivity advantage for low spatial frequencies could be accounted for by the greater light-concentrating abilities of its optics. Contrast sensitivity to 4 cpd was poor or absent in the scotopic range for both species. For both, scotopic increment thresholds were proportional to the square root of retinal illuminance, in accordance with the deVries–Rose law. Overall, cat and human visual systems appear to operate under very similar constraints for rod vision, including the regulation of contrast sensitivity across adaptation levels. A companion paper compares sensitivity of neurons in the lateral geniculate nucleus to these behavioral data.

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