Spherical Soft Contact Research Articles

Intraocular Straylight and Multifocal Soft Contact Lens Fit With a Myopia Control Approach.

Center-distance multifocal contact lenses (MFCLs) are used to slow myopia progression. We examined the effect of two MFCLs on intraocular straylight values in myopic individuals. Twenty-five young myopic adults were enrolled and were fit with three contact lenses (Biofinity sphere, Biofinity Multifocal, and NaturalVue Multifocal) in a random order over two study visits. Pupil size (NeurOptics VIP-300, Laguna Hills, CA) and contact lens centration were measured. Right eye intraocular straylight measurements were collected (OCULUS C-Quant; Wetzlar, Germany) and compared with a spectacle trial lens. Log straylight (LogSL) values and straylight residuals were analyzed using repeated-measures analyses of variance with Tukey-corrected post hoc t -tests. The mean participant age (±SD) was 24.1±1.5 years, and right eye spherical equivalent refractive error was -3.38±1.53 DS. There was no difference in mesopic pupil size between visits ( P =0.68) and no difference in contact lens centration between lenses ( P =0.99). LogSL values differed by lens type ( P =0.004). LogSL with the spectacle trial lens was significantly greater than with each contact lens type (all P <0.05), but there were no significant differences in LogSL between the three contact lenses (all P >0.05). There was no difference between the three contact lens designs for straylight residuals ( P =0.33). Measured intraocular straylight for both MFCLs was not different than with a spherical soft contact lens. A significant increase in intraocular straylight with spectacle trial lens correction was observed compared with all contact lenses.

PREVALENSI PENDERITA MYOPIA YANG DIREHABILITASI DENGAN LENSA KONTAK LUNAK DI OPTIK KARTIKA JAYA

This study aims to determine the description of the wearer of spherical soft contact lenses as a tool to rehabilitate the visual acuity of patients with myopia refractive error at Kartika Jaya optics Bekasi. The population in this study were all patients with refractive errors who used a soft contact lens vision rehabilitation tool. This type of research is descriptive analytic with a design description of the use of spherical soft contact lenses. The sampling system used in this study is a document research method from the same source, namely all customers who were examined at Kartika Jaya optics. Analysis of hypothesis testing using SPSS version 24, which resulted in: the rehabilitation of visual acuity of patients with refractive errors of myopia using colorless spherical soft contact lenses was quite significant and the use of colored soft toric contact lenses was not significant.

Clinical performance and Willingness To Pay for soft toric contact lenses in low and moderate astigmats

PurposeTo determine clinical performance and the ‘Willingness To Pay’ for toric vs. spherical soft contact lenses in an astigmatic population. MethodsIn the clinical study, subjects with binocular low to moderate astigmatism (-0.75DC to −1.50DC) wore pairs of soft toric (Biofinity toric) and spherical (Biofinity) contact lenses in random sequence. Visual acuity (high and low contrast, monocular and binocular), subjective comfort and subjective vision were recorded. In the economics study, first subjects who had participated in the clinical study were presented with a series of randomised economic scenarios in order to determine their Willingness To Pay a premium (i.e. an increase) for toric lenses. Then, a similar set of scenarios were presented to a much larger group of online respondents and again, Willingness To Pay was established. ResultsFor the four measures of visual acuity, the Biofinity toric lens out-performed the Biofinity spherical lens by 0.6 to 1.1 lines.. Subjective vision performance was statistically significantly better with the toric lens for the distance task only. Comfort scores were not significantly different. Similar findings for Willingness To Pay were established for the clinical subjects and for the online respondents. The Willingness To Pay premium (additional fee) for a monthly supply of toric lenses (over spherical lenses) was between £13 and £16, if a toric lens provides better vision and similar comfort, as shown in the clinical study. ConclusionConsumers are willing to pay a monthly premium of around 50% to benefit from the typical experience of better vision and similar comfort for toric vs. spherical lenses. The level of additional cost for toric lenses compared to their spherical equivalents is less than this in the market, so eye care professionals should consider that toric lenses are delivering a greater clinical return than anticipated by wearers for the relatively small increase in price.

Toric versus spherical soft contact lenses in the correction of low to moderate astigmatism

Danya Lahmami reviews the published evidence comparing the correction of astigmatism with either spherical or toric soft contact lenses. This is an edited version of the 2020 City University/Optician Best Dissertation prize-winner (C105880, suitable for logging as one distance learning CPD point for optometrists, contact lens opticians and dispensing opticians)

Evaluation of corneal biomechanical properties in spherical and toric soft contact lens wear

Purpose: Corneal hysteresis (CH) and corneal resistance factor was found to be less for patient wearing toric contact lens as compared to soft spherical CH was calculated as the difference in air pressures between force-in applanation (P1) and force-out applanation (P2), or (P1–P2). Materials and Methods: This was the prospective study, 40 eyes of 22 patients with mean age of 22.09 ± 4.05 years. Eleven eyes were fitted with soft toric contact lens and 29 eyes were fitted with soft spherical contact lens. Dry eye, keratoconic or any systemic pathology were excluded. Soft toric and soft spherical contact lenses (Comfilcon A, Coopervision, and Southampton, UK) were fitted. The Ocular response Analyzer (Reichert Ophthalmic Instruments, Depew, New York, USA) was used to measure CH before and after 3 months using soft toric and soft spherical contact lenses. Descriptive statistics were used to analyze the demographic data. Paired t-test was employed for analyzing the difference between the base line value of CH with soft toric and soft spherical contact lens wearers after 3 months. Independent t-test was used to find the association between CH and gender. Results: CH was found to be lesser after 3 months of soft toric contact lens wear, as compared with soft spherical contact lenses. Mean increase of CH was found to range from 10.44 ± 0.96to 10.80 ± 0.96 mmHg (P = 0.000). Conclusion: In this study, there was a decrease in CH after using soft toric contact lenses and increase after using soft spherical contact lenses for 3 months. The increased CH with soft spherical contact lens was reversible in nature. However, CH may differ between lens type and modality of wear which can lead to long-term changes in the corneal biomechanical properties.

Greater higher order aberrations induced by toric orthokeratology versus soft toric multifocal contact lens wear.

Spherical orthokeratology and soft multifocal contact lenses are commonly used for myopia control and correction, but have been shown to increase spherical aberration, coma and total higher order root mean square (HORMS) aberrations. There are limited myopia control contact lens options for patients with moderate to high astigmatism. The purpose of this study was to quantify changes in higher order aberrations (HOA) in myopic astigmatic eyes fitted with toric orthokeratology (TOK) and soft toric multifocal (STM) contact lenses. Ocular wavefront aberrations were measured in both eyes of 30 adult subjects and are reported through the 6th radial order over a 5mm, dilated pupil. All eyes met refractive criteria of myopia (-5.00 D to plano) and cylinder (-3.50 to -1.25 D). Three measurements were taken at baseline and after 10±2days of lens wear (TOK, STM). Sixteen subjects achieved logMAR high contrast visual acuity of 0.30 or better in both eyes and were included in this analysis. Repeated measures analysis of variance and post-hoc paired t-tests were used, as appropriate, with Benjamini-Hochberg correction. Higher order root mean square, spherical aberration (C12), and coma RMS (C7, C8) increased with TOK (0.641 [0.222], 0.409 [0.157], 0.426 [0.187] µm, respectively) and STM (0.481 [0.107], 0.223 [0.139], 0.320 [0.130] µm, respectively) from baseline (all p<0.001). TOK was elevated compared to STM for HORMS (p=0.03), spherical aberration (p=0.001) and coma RMS (p=0.04). Toric orthokeratology induced more HORMS, spherical aberration and coma RMS than STM in myopic astigmats; however, both lens types showed an increase in HOA compared to baseline, which placed patients outside the age and pupil size matched normative ranges. While the optical changes that accompany these modalities are helpful for myopia management, the induction of HOAs may have unintended consequences on visual performance.

Induced Refractive Error Changes the Optical Coherence Tomography Angiography Transverse Magnification and Vascular Indices

To assess the effect of changing anterior eye refractive power with contact lenses on the transverse magnification of en face images and associated vascular indices from optical coherence tomographic angiography (OCT-A). Prospective crossover study. Spherical soft contact lenses (-6 diopter [D] to +6 D in 2 D steps) were used to induce anterior eye refractive power changes in 11 healthy young adults and 3×3-mm macular scans were captured using OCT-A (Zeiss AngioPlex, software version 11.0; Cirrus HD-OCT 5000, Carl Zeiss Meditec Inc). Image transverse magnification was predicted based on refraction and biometry measurements and compared with empirical changes in the en face images measured with image analysis. Linear regression analysis was performed to assess the relationship between induced refractive ametropia and foveal avascular zone (FAZ) area, perimeter, circularity, and vessel density and perfusion density. The predicted transverse magnification was linearly related to induced refractive ametropia and to the empirical transverse magnification changes (average slope: 1.02, 95% CI: 0.90-1.34). All the OCT-A indices showed linear relationships with induced refractive ametropia (P < .05) with the 12 D tested range altering the indices by 7% to 12%. After correcting for transverse magnification, all OCT-A indices except FAZ area were linearly related to induced refractive ametropia (P < .05) and were reduced to 1% to 9%. This study is the first to show that induced refractive ametropia can affect OCT-A image magnification and indices. These changes are clinically important and need to be considered along with biometry effects when interpreting OCT-A indices. Transverse magnification changes can affect the ability of OCT-A to precisely measure linear dimensions of blood vessels.

The effect of contact lens wear on retinal spectral domain optical coherence tomography

BackgroundThis study assessed the impact of contact lens wear on retinal spectral domain optical coherence tomography (SD‐OCT) image quality and macular thickness measurements, among subjects with myopia.MethodsThis was a prospective study including 34 subjects (26.59 ± 3.19-years) with myopia or myopic astigmatism. Twelve were imaged wearing spherical soft contact lenses, eight non‐contact lens wearers were imaged with a plano soft contact lens, and 14 with significant astigmatism were fitted with a rigid gas permeable (RGP) contact lens. For each group of contact lens types, the average image quality index (Q‐index), and the average macular thickness measurements were compared between macular OCT scans obtained from the same eyes with and without a contact lens.ResultsAmong the subjects assessed with their habitual spherical soft lenses, the average Q‐index was similar for scans acquired with and without a contact lens (30.10 ± 1.94 versus 31.03 ± 2.55; p = 0.18). Among non‐contact lens wearers, the average Q‐index was slightly higher for scans acquired without a contact lens, compared to scans with a plano contact lens (31.99 ± 2.06 versus 29.51 ± 1.56; p = 0.006). Among 14 subjects imaged wearing a fitted RGP contact lens, the Q‐index was similar for scans acquired with and without a contact lens (29.04 ± 2.73 versus 28.75 ± 2.86; p = 0.78). In all groups, there were no correlations between the power of the sphere and change in the Q‐index (that is, post‐ minus pre‐contact lens Q‐index), and no differences were found between OCT‐derived macular thickness measurements from scans with and without a contact lens. The magnitude of cylinder was not correlated with the change in the Q‐index in the habitual and RGP contact lens groups. However, an inverse correlation between cylinder power and change in the Q‐index was found in the plano contact lens group.ConclusionIn low to intermediate levels of myopia, with or without regular astigmatism, macular SD‐OCT imaging does not merit placement of a soft or rigid contact lens, nor is there an added benefit from removing a habitual spherical soft lens prior to scanning.

Essential contact lens practice 7 – Soft contact lens fitting

In the seventh article in our major series about modern contact lens practice edited by Dr Rachel Hiscox, Dr Byki Huntjens offers a practical overview of the key aspects and principles associated with spherical soft contact lens fitting.

Comparing Visual Acuity and Frontal Area Topography in Prescription of Spherical and Toric Soft Contact Lens

Comparing Visual Acuity and Frontal Area Topography in Prescription of Spherical and Toric Soft Contact Lens

Study on the Pupil Center Offset and High-order aberration after Wearing Spherical Soft Contact Lens in Young Myopes

Study on the Pupil Center Offset and High-order aberration after Wearing Spherical Soft Contact Lens in Young Myopes

Correcting progressive myopia with bifocal contact lenses with central zone for distant vision: changes in accommodation and axial length (a preliminary report)

To assess the state of accommodation and the dynamics of changes of ocular axial length in patients with progressive myopia who use bifocal soft contact lenses (BFSCLs). The main and control groups consisted of 50 children (100 eyes) each. Patients of the main group used BFSCLs with distance-oriented central zone and added power of 4 D on the periphery. Patients of the control group were corrected with spherical soft contact lenses (SSCLs). Baseline measurements included amplitude of accommodation (AA), positive relative accommodation (PRA) and the length of anterior-posterior axis of the eye. All patients were examined before wearing SCLs and every 3 months during the entire period of observation lasting 9 to 12 months. Correction of myopia with contact lenses is accompanied by the increase of AA and RPA. The users of BFSCLs with distance-oriented central zone and added power of 4 D on the periphery, which induces myopic peripheral defocus, had their accommodative function normalize much faster than the patients wearing SSCLs. The average increase in the ocular axial length in the BFSCLs group appeared to be significantly smaller than in the SSCLs group (0.11 and 0.58 D, respectively), which can be attributed to the simultaneous formation of the central focus and induced peripheral myopic defocus.

A Randomized Trial to Evaluate the Effect of Toric Versus Spherical Contact Lenses on Vision and Eyestrain.

Objectives:To compare the effect of toric versus spherical soft contact lenses on objective measures of visual performance using visual acuity and electromyography of the orbicularis oculi muscle.Methods:Current soft contact lens wearers with −0.75 to −1.75 D astigmatism in each eye were binocularly fitted with toric (1-Day ACUVUE MOIST for astigmatism) and spherical (1-Day ACUVUE MOIST) contact lenses in random order. After each fitting and at 1-week follow-up, high- and low-contrast visual acuities were measured. Electromyography was used to objectively evaluate eyestrain. Linear mixed models were used to assess differences between toric and spherical contact lenses.Results:The mean age (±SD) of the 60 participants was 27.5±5.0 years, spherical refractive error was −3.68±2.01 D, and cylinder was −1.28±0.36 D. High- and low-contrast visual acuities with toric lenses were better than with spherical lenses at both fitting (toric high-contrast: −0.065±0.078 and low-contrast: 0.133±0.103 vs. spherical high-contrast: 0.001±0.104 and low-contrast: 0.224±0.107) and follow-up (toric high-contrast: −0.083±0.087 and low-contrast: 0.108±0.107 vs. spherical high-contrast: −0.015±0.095 and low-contrast: 0.211±0.104) (all P<0.0001). Electromyography-measured eyestrain was less with toric versus spherical contact lenses at fitting (least-square ratio of toric over spherical=0.72; P=0.0019) but not at follow-up (ratio=0.86; P=0.11).Conclusion:These results suggest that toric contact lenses provided improved objective measures of vision in a low-to-moderate astigmatic population.

Efficacy of Toric Contact Lenses in Fitting and Patient-Reported Outcomes in Contact Lens Wearers.

To assess whether patient-reported measures are improved with soft toric contact lenses (TCLs) compared with soft spherical contact lenses (SCLs) and whether clinical time needed to fit TCL is greater than SCL. Habitual contact lens wearers with vertexed spherical refraction +4.00 to +0.25 D or -0.50 to -9.00 D and cylinder -0.75 to -1.75 DC were randomly assigned to be binocularly fitted into a TCL or SCL, and masked to treatment assignment. Time to successful fit was recorded. After 5 days, the National Eye Institute Refractive Error Quality of Life Instrument (NEI-RQL-42) and modified Convergence Insufficiency Symptom Survey (CISS) were completed. After washout, subjects were fit into the alternative lens design (TCL or SCL). Outcomes were evaluated using linear mixed models for the time to fit and CISS score, generalized linear model for the successful fit, and Wilcoxon tests for the NEI-RQL-42. Sixty subjects (71.7% women, mean age [±SD] = 27.5±5.0 years) completed the study. The mean time to fit the TCL was 10.2±4.3 and 9.0±6.5 min for the SCL (least square [LS] mean difference (TCL-SCL)=1.2, P=0.22). Toric contact lens scored better than SCL in global NEI-RQL-42 score (P=0.006) and the clarity of vision (P=0.006) and satisfaction with correction subscales (P=0.006). CISS showed a 15% reduction in symptoms (LS mean difference [TCL-SCL]=-2.20, P=0.02). TCLs are a good option when trying to improve the vision of patients with low-to-moderate astigmatism given the subjective improvements in outcomes.

A comparison of toric and spherical soft contact lenses on visual quality of life and ease of fitting in astigmatic patients

A comparison of toric and spherical soft contact lenses on visual quality of life and ease of fitting in astigmatic patients

Spherical Soft Contact Lens Designs and Peripheral Defocus in Myopic Eyes.

Peripheral retinal defocus has been implicated in myopia progression. The effect of commercially available spherical soft contact lenses (SCLs) on peripheral defocus of adult myopic eyes was investigated. Twenty-five young adults with spherical equivalent (SE) refractions between -0.50D and -6.00D were enrolled. Cycloplegic autorefraction (right eye) was measured centrally and ±20°, ±30°, and ±40° from the line of sight along the horizontal meridian using an autorefractor. Four commercially available spherical SCLs (Biofinity, Acuvue2, PureVision2, and Air Optix Night & Day Aqua) were evaluated. SE defocus (M) was used to calculate relative peripheral defocus (RPD) while wearing each SCL and relative peripheral refraction of the uncorrected eye. Spherical aberration (SA) changes caused by each SCL were measured along the line of sight by aberrometry. Peripheral defocus was analyzed using repeated-measures analyses of variance (RM-ANOVA). The association between changes in axial SA and the change in peripheral defocus was evaluated using linear mixed models. The mean age (±SD) and central SE refractive error were 24.0 ± 1.3 years and -3.45 ± 1.42D, respectively. PureVision2 did not change RPD (P = .33). Significant myopic shifts on the temporal retina were found with three lenses: Acuvue 2 (-0.29D at 30°; -0.80D at 40°; both P ≤ .01), Biofinity (-1.21 D at 40°; P = .02), and Air Optix Night & Day Aqua (-0.23D at 20°, -0.48D at 30°, and -1.50D at 40°; all P < .004). All SCLs caused a negative change in SA. SCLs inducing less negative (more positive) SA changes were associated with a less hyperopic change in RPD. Spherical SCL design can influence the peripheral defocus profile experienced by a myopic eye. Several, but not all, SCLs reduced peripheral hyperopia. Differences in how SCL types influence peripheral defocus may have implications for myopia progression.

The impact of silicone hydrogel contact lenses on the measurement of intraocular pressure using non-contact tonometry

Background/Aim. Measurement of intraocular pressure (IOP) over therapeutic silicone hydrogel soft contact lenses by a non-contact method of tonometry could be applied in opthalmologic practice but the results obtained are still controversial. The aim of this study was to evaluate the effect of spherically designed silicone hydrogel soft contact lenses and their power on values of IOP measured by using a noncontact tonometry method. Methods. We measured IOP with and without spherical silicone hydrogel soft contact lenses on 143 eyes of 80 subjects who did not have any ocular or systemic diseases. Results. The Wilcoxon statistical analysis test for ranking average values of IOP measured on 143 eyes over a spherical silicone hydrogel soft contact lenses showed significantly higher values compared to those measured with no contact lenses (15.81 ? 3.46 mm Hg vs 14.54 ? 3.19 mm Hg; respectively; Z = -5.224, p = 0.001). Refractive power analysis of the contact lenses of -9.00D to +6.00 D showed a significant difference of IOP in the range from 0.00D to -6.00D. Conclusion. Non-contact tonometry is not an accurate method of IOP measuring over spherical silicone hydrogel soft contact lenses which belong to therapeutic contact lenses.

Low-coherence interferometer for contact lens surface metrology

Contact lens performance depends on a number of lens properties. Many metrology systems have been developed to measure different aspects of a contact lens, but none test the surface figure in reflection to subwavelength accuracy. Interferometric surface metrology of immersed contact lenses is complicated by the close proximity of the surfaces, low surface reflectivity, and instability of the lens. An interferometer to address these issues was developed and is described here. The accuracy of the system is verified by comparison of glass reference sample measurements against a calibrated commercial interferometer. The described interferometer can accurately reconstruct large surface departures from spherical with reverse raytracing. The system is shown to have residual errors better than 0.05% of the measured surface departure for high slope regions. Measurements made near null are accurate to λ/20. Spherical, toric, and bifocal soft contact lenses have been measured by this system and show characteristics of contact lenses not seen in transmission testing. The measurements were used to simulate a transmission map that matches an actual transmission test of the contact lens to λ/18.

Low toric soft contact lens acceptance study.

The aim of the study was to evaluate the objective and subjective visual performance of custom toric contact lenses (TL) and their spherical off-the-shelf counterparts (SL) in subjects with low amounts of astigmatism. Twenty-three habitual soft lens wearers (40 eyes, 25-35 years) manifesting 0.50-1.00DC and ≤±3.00DS were recruited. Air Optix Aqua (Lotrafilcon B) was fit using the spherical equivalent of the manifest refraction. Intelliwave toric in Efrofilcon A (Definitive) was fit using the manifest refraction and keratometric data. Comprehensive visual performance tests were done through manifest refraction in a trial frame; in SL; and in TL. A subjective evaluation of quality of vision was also obtained. ANOVA revealed that, at the morning visit (AM), high contrast logMAR distance visual acuity (HCDVA) was significantly better (p<0.01) in spectacles as compared to SL. A similar trend was noted at the afternoon visit (PM). In addition, at the PM visit, HCDVA was significantly better (p<0.01) for TL as compared to their SL. ANOVA revealed that, at the PM visit, low contrast distance visual acuity (LCDVA) was significantly better (p=0.05) in spectacles as compared to SL. None of these differences were clinically significant. In addition, no statistically significant difference (p>0.05) in subjective vision rating scores was noted between SL and TL. The present investigation found no clinically significant difference in visual performance between spherical and toric soft contact lenses in low astigmats.

Peripheral Defocus with Spherical and Multifocal Soft Contact Lenses

To describe peripheral defocus when myopic eyes are corrected with spherical and center-distance multifocal soft contact lenses while looking at distance and near. Twenty-five young adults with spherical contact lens-corrected refractive error of -0.50 to -6.00 D participated. Refractive error of each participant's right eye was measured while it wore a spherical soft contact lens (Biofinity) and again while it wore a center-distance multifocal soft contact lens with a +2.50-D add (Biofinity Multifocal "D"). Measurements were made centrally and along the horizontal meridian at ±20, ±30, and ±40 degrees from the line of sight at distance and near (3.33-D demand). The mean (±SD) age and spherical equivalent refractive error were 23.8 ± 1.3 years and -3.62 ± 1.56 D, respectively. At distance, the multifocal contact lens resulted in significantly more myopic defocus than the spherical contact lens at the 40- and 30-degree locations on the nasal retina and at the 20- and 30-degree locations on the temporal retina (p < 0.0001). When accommodating to a near target, peripheral defocus was more myopic with the multifocal lens than with the spherical lens (p < 0.0001). When viewing the near target with the spherical lens, participants experienced foveal hyperopic defocus and peripheral hyperopic defocus at all but one peripheral location. While participants also experienced foveal hyperopic defocus with the multifocal when looking at near, peripheral defocus was minimal (not significantly different than zero) at several locations (i.e., peripheral emmetropia). The center-distance multifocal lens created peripheral myopic defocus when looking at distance. When looking at near, the multifocal lens resulted in relatively more myopic (less hyperopic) peripheral defocus than the spherical lens. The defocus profiles experienced with the multifocal contact lens in this study make it a good candidate for studies seeking to examine the effect of peripheral myopic defocus on myopia progression in children.