Silicone Hydrogel Soft Contact Research Articles

Optical Characterization of Hydrogel and Silicone Hydrogel Soft Contact Lenses

Contact lenses are biomaterials that have emerged as an alternative to glasses in correcting vision defects. In this study, commercial nesofilcon A (hydrogel-Hy) and delefilcon A (silicone hydrogel-SiHy) daily disposable soft contact lenses were optically examined using UV-visible light spectroscopy. Optical absorption and transmittance measurements of the lenses were taken with a UV-visible spectrophotometer, and their properties of blocking the harmful part of the radiation to the eye and transmitting the harmless part were investigated. From the absorption spectrum, it was seen that the nesofilcon A lens absorbed ultraviolet light better. From the optical absorption coefficient spectra of nesofilcon A and delefilcon A lenses, the absorption edges were obtained as 386 and 325 nm, and the optical band gap values were 3.37 and 3.98 eV, respectively. Additionally, the refractive index profiles of the lenses were plotted. The refractive indices of the lenses at 550 nm wavelength were calculated as 1.55 and 1.77 for nesofilcon A and delefilcon A, respectively. While the delefilcon A lens transmitted visible light well, the nesofilcon A lens blocked UV light better and its refractive index was determined to be closer to the 1.40 the value specified by the manufacturer.

Epidemiological survey of two morphotypes of Demodex folliculorum (Prostigmata: Demodicidade) in young people from southern Spain

Different morphotypes of Demodex from humans have been described. Among them, molecular studies have made it possible to discern between the Demodex folliculorum and Demodex brevis. Further studies showed two morphotypes of D. folliculorum harboured two different habits (human skin and human eyelashes), both of them with finger-shaped terminal opisthosoma difficult to differentiate and that can be assigned to D. folliculorum,Thus, a complete morphometric study of the species, which in this study are referred to as Demodex folliculorum species complex, was carried out. From this morphometric and meristic study two distinct morphological forms (short and long) could be identified within the Demodex folliculorum species complex. These forms differ significantly in four out of the six biometric parameters we analysed: gnathosomal length and width, podosomal width, and opisthosomal length. Moreover, a comprehensive survey of the two morphotypes from different habitats (skin and eyelashes), was carried out in young people of Southern Spain. Therefore, an analysis of 104 asymptomatic students, which were contact lens wearers, and the presence of D. folliculorum was carried out. A statistical analysis based on Bayesian zero inflated Poisson GLM has been applied to our sample data. For the age group considered (18–24 years old), the overall D. folliculorum prevalence for skin face or eye infections (at least one of them) was 19.31 % (51 people), with a statistically significant higher prevalence in males men. Furthermore, there is a slight statistical correlation between the presence of Demodex in silicone hydrogel soft contact lens wearers. This study confirms: i) the existence of two morphotypes of D. folliculorum that appear segregated due to the parasitization microhabitats,ii) a higher prevalence of mites in men than in women, iii) the existence of a high number of statistically supported double infections (skin-eyelashes). It also provides epidemiological data on the prevalence of long and short forms of D. folliculorum in a healthy young population.

Silicone hydrogel versus hydrogel soft contact lenses for differences in patient-reported eye comfort and safety: A Cochrane systematic review summary.

This work is significant because it is the first Cochrane systemic review that compares the comfort and safety of hydrogel and silicone hydrogel soft contact lenses (SCL). This study aimed to conduct a systemic review of randomized trials comparing the comfort and safety of silicone hydrogel and hydrogel SCLs. CENTRAL, MEDLINE Ovid, EMBASE.com, PubMed, LILACS, ClinicalTrials.gov, and World Health Organization International Clinical Trials Registry Platform were searched on or before June 24, 2022, to identify randomized clinical trials that compared silicone hydrogel and hydrogel SCLs. Seven trials were identified and evaluated. One trial reported Ocular Surface Disease Index results, with the evidence being very uncertain about the effects of SCL material on Ocular Surface Disease Index scores (mean difference, -1.20; 95% confidence interval, -10.49 to 8.09). Three trials reported visual analog scale comfort score results, with no clear difference in comfort between materials, although results were of low certainty; trial results could not be combined because the three trials reported results at different time points. None of the included trials reported Contact Lens Dry Eye Questionnaire 8 or Standard Patient Evaluation of Eye Dryness scores. There was no evidence of a clinically meaningful difference (>0.5 unit) between daily disposable silicone hydrogel and hydrogel SCLs in corneal staining, conjunctival staining, or conjunctival redness (very low certainty evidence). The overall evidence for a difference between all included silicone hydrogel and hydrogel SCL trials was of very low certainty, with most trials judged as having a high overall risk of bias. There was insufficient evidence to support recommending one SCL material over the other. Future well-designed trials are needed to generate high certainty evidence to further clarify differences in SCL material comfort and safety.

Subjective Symptoms of First-Time Wearers of Verofilcon A Silicone Hydrogel One-Day Disposable Contact Lenses: A First Time Use of Verofilcon A (FTVeA) Study.

Purpose: Verofilcon A, a new daily disposable silicone hydrogel soft contact lens (SCL), is expected to be more comfortable to wear due to its smooth surface. This study aims to compare the comfort level of verofilcon A with eyeglasses in first-time SCL wearers. Methods: A total of 58 new SCL wearers participated in this study. Participants' comfort scores while wearing glasses or verofilcon A were examined at baseline (glasses) and one and four weeks after starting to wear the SCLs. Results: At the end of the one-month study period, no participants had abandoned wearing the SCLs due to discomfort. The vision scores (1-10) for glasses (baseline) and SCLs (week one, week four) were better withSCLs than glasses in the morning (7.9 ± 1.9 vs 8.9 ± 1.3, 9.0 ± 1.2, p<0.01), during the day (8.0 ± 1.6 vs 9.0 ± 1.1, 8.9 ± 1.2, p<0.01), at the end of the day (7.2 ± 2.1 vs 8.5 ± 1.5, 8.7 ± 1.4, p<0.01), and the entire day (7.7 ± 1.7 vs 8.9 ± 1.2, 8.7 ± 1.3, p<0.01). The percentages of participants who agreed that wearing SCLs at week four was as good as or better than glasses in terms of overall vision, peripheral vision, vision at the end of the day, comfort during the day, comfort at the end of the day, less fatigue during the day, and less fatigue at the end of the day were 91.4%, 100.0%, 91.4%, 89.7%, 82.8%, 87.9%, and 89.7%, respectively. Of the participants, 93.1%, 100.0%, and 93.1% felt that the SCLs were easy to wear, more comfortable than expected, and would like to purchase the same lenses in the future, respectively. Conclusion: These findings suggest that verofilcon A is more comfortable than glasses and is effective as an introductory lens for first-time SCL wearers.

Adhesion of Asian Dust Particles to Verofilcon a Soft Contact Lenses.

Asian dust poses a serious global health hazard. Airborne particles adhering to contact lenses may cause substantial damage to the ocular surface. The recently released one-day disposable silicone hydrogel soft contact lens (SCL), the verofilcon A, has a smooth surface with SMARTSURFACE® technology, which is designed to prevent adhesion of protein components and foreign bodies. The purpose of this study was to verify the protective quality of verofilcon A SCL against adhesion of Asian dust particles to its surface. Verofilcon A and etafilcon A (control lens) SCLs were used (n=16 per group), and 0.2 mL of physiological saline containing 0.01 mg/mL of Asian dust particles was dropped on the surface of SCLs, allowed to stand for 1 hour, shaken for 1 minute, and rinsed three times with saline (after rinsing). In addition, the samples were agitated by a vortex mixer for 1 minute and rinsed three times with saline (after vortex). The number of Asian dust particles adhering to the SCLs and percentage of the surface area occupied by the Asian dust particles was determined before washing, after rinsing, and after vortexing. The number of adherent Asian dust particles was lower on verofilcon A SCL (297 ± 116 after rinsing, and 5 ± 14 after vortexing) than on etafilcon A SCL (523 ± 212 after rinsing, p=0.003, and 378 ± 268 after vortexing, p<0.001). The Asian dust adhesion area was also lower on verofilcon A SCL (3.6 ± 2.3% after rinsing and 0.0 ± 0.1% after vortexing than on etafilcon A (10.2 ± 2.1% after rinsing, p=0.002, and 5.2 ± 3.0% after vortexing, p<0.001). These findings indicate that verofilcon A SCL has the property of low adhesion of Asian dust particles. Verofilcon A SCL can be recommended for SCL wearers during windy and Asian dust days.

Brinzolamide-loaded soft contact lens for ophthalmic delivery.

Aim: In this study, brinzolamide (BRZ) was loaded in balafilcon A silicone hydrogel soft contact lens to enhance delivery in glaucoma therapy. Materials & methods: BRZ-loaded soft contact lens was prepared by the soaking method with optimization of pH, temperatureand concentration of drug loading solution. Results: At pH 7.4, loading temperature and concentration of 32°C and 3mg/ml, respectively, enhanced drug loading capacity and release wereobserved. Diffusional experiments showed Higuchi model of release. BRZ loading brought no appreciable changes in the physical properties of soft contact lens, likewise, maintaining stability. Conclusion: The results demonstrated BRZ loading and delivery through silicone hydrogel soft contact lens which provides a potential alternative in glaucoma therapy.

Corneal hysteresis and intraocular pressure are altered in silicone-hydrogel soft contact lenses wearers

PurposeThe aim of this work is to determinate the effects in the physical parameters in terms of intraocular pressure (IOP) and central corneal thickness (CCT) and corneal biomechanics in terms of corneal resistance factor (CRF) and corneal hysteresis (CH) of wearing silicone-hydrogel soft contact lenses (SiH-CLs) in young adult subjects during a short-term follow-up.Methods40 eyes of 20 healthy patients with a mean age of 22.87 ± 4.14 were involved in this study. Subjects with corneal diseases, dry eye, irregular astigmatism or who have been previous contact lens wearers were excluded. The ocular response analyzer (Reichert Ophthalmic Instruments) was used to measure CH, CRF and IOP and Scheimpflug imaging (the GALILEI™ Dual Scheimpflug camera analyzer, Ziemer) was used to measure CCT before and 10 days (Group 1) and 20 days (Group 2) after wearing the SiH-CLs.ResultsIOP was significantly decreased 10 days after using the SiH-CLs (p = 0.009). Within the 20 days' period, Group 2 revealed an even more pronounced decrease in IOP (p = 0.003) while CH increased significantly (p = 0.04). CCT and CRF did not show a significant change during the period of SiH-CLs use. Our finding allowed obtaining an empirical expression that relates IOP, CCT, CRF and CH within a biomechanical compensation experimental model.ConclusionsCorneal biomechanical parameters and physical properties of the cornea may be altered due to SiH-CLs use. Our findings could have an impact on the management of glaucoma progression and ocular hypertension.

Use of Autologous Serum Eye Drops with Contact Lenses in the Treatment of Chemical Burn-Induced Bilateral Corneal Persistent Epithelial Defects.

Objective We aim to evaluate the clinical effect of combined topical 20% autologous serum eye drops (ASEs) along with silicone–hydrogel soft contact lenses (SCLs) in the treatment of chemical burn-induced bilateral corneal persistent epithelial defects (PEDs) and to review the literature of related studies. Methods From January 1, 2017, to December 31, 2019, we conducted a retrospective chart review of 8 patients with chemical burn-induced bilateral corneal PEDs who were unsuccessfully treated with conventional medical therapy and were then treated with combined topical 20% (v/v) ASEs and silicone–hydrogel CLs. The clinical effects and effectiveness of the combined treatment were evaluated. Results The bilateral corneal PEDs healed in all sixteen eyes of the eight patients within 2 weeks. The patients did not report any discomfort associated with the combined treatment. Improved ocular comfort/visual acuity and decreased conjunctival injection correlated with healing. No recurrent corneal epithelial breakdown was noted during the 3-month posttreatment follow-up. Conclusions The combined treatment of silicone–hydrogel CLs and ASEs can help to stabilize the ocular surface and successfully treat chemical burn-induced bilateral corneal PEDs. It may be considered as an alternative treatment method for patients with bilateral chemical burn-induced corneal PEDs with potential corneal melting.

Silicone hydrogel versus hydrogel soft contact lenses for differences in patient-reported eye comfort and safety

Silicone hydrogel versus hydrogel soft contact lenses for differences in patient-reported eye comfort and safety

Shape of the anterior surface of the cornea after extended wear of silicone hydrogel soft contact lenses.

To measure geometrical changes in the anterior surface of the cornea after wearing silicon hydrogel (SiH) soft contact lenses continuously for 1week. Forty-three eyes with 3.0D of myopia and 22 eyes with 3.0D of hyperopia were enrolled in the prospective, interventional study. All subjects underwent a general eye examination, corneal tomography with wavefront aberration analysis, corneal thickness measurements and epithelial thickness mapping before and after wearing SiH lenses (Acuvue Oasys) for 7days. No significant changes in average keratometry were observed in either refractive group. In the myopic group, keratometry findings for the flat meridian (K1) and central corneal thickness decreased significantly. After +3.0 D lens wear in the hyperopic group, a significant decrease in epithelial thickness up to 3.19µm was observed in the central and paracentral cornea, (p<0.001). In both refractive groups, the largest epithelial thickness increase was seen in the periphery. A decrease in spherical aberration was noted in myopic eyes, while an increase of both higher order corneal aberrations and coma was found in hyperopic subjects. Extended wear of SiH lenses results in a significant change in epithelial thickness leading to alteration in the geometry of the anterior surface of the cornea, particularly in hyperopic patients. These epithelial thickness variations lead to changes in the higher order aberrations of the cornea.

Compressive behaviour of soft contact lenses and its effect on refractive power on the eye and handling off the eye.

PurposeTo investigate the stress-strain behaviour of 9 soft contact lens materials, that are commonly used in the market, under uniaxial compression loading.MethodsSeven types of hydrogel and two types of silicone-hydrogel soft contact lens materials were hydrated in phosphate-buffered saline (PBS) solution then subjected to uniaxial compression loads. The load rate was set to 16.0 N/min starting with two consecutive initial 5.0 N loading cycles followed by three relaxation periods of 4.0 min within which there were two more 5.0 N loading cycles and eventually, a full loading cycle that stopped at a load of 49.0 N. The load and contraction data obtained experimentally were analysed to derive the stress-strain behaviour. Finite Element (FE) analysis was then utilised to evaluate the performance of soft contact lenses on the human eye and handling lenses off the eye.ResultsUnlike tensile tests, all tested materials showed nonlinear behaviour when tested under compression. When fitted to first-order Ogden hyperelastic model, parameter μ was found to be varying in the range 0.12 to 0.74 MPa and material parameter α was found to be varying in the range 8.2 to 20.326 among the nine tested materials. Compression modulus of elasticity was 2.2 times higher than the tensile modulus of elasticity on average. FE simulation with nonlinear Ogden constitutive model showed a limited change (8%~12%) in the optical performance when compared to other material models, however, it predicted higher stress when the lens was simulated under bending during off-eye handling.ConclusionsCompression tests revealed slightly nonlinear behaviour when materials were strained under compression stress down to 15% ~ 30% of their nominal heights. Considering the physiological compression loading range of 8 mmHg, secant moduli of elasticity were 1.5% to 6.9% higher than the tension moduli of elasticity depending on the material. Tensile-based moduli of elasticity could be used in FE analysis as a step towards simulating the optical performance of soft contact lenses on-eye. However, nonlinear compression-based material models are recommended for FE analysis of soft contact lenses when lens-handling is investigated off-eye.

Solid Platelet‑rich Plasma Combined with Silicone-hydrogel Soft Contact Lens for Non-healing Corneal Ulcers: A Case Series

ABSTRACT Purpose: To present a case series of non-healing corneal ulcers treated by solid activated platelet-rich plasma (PRP) combined with silicone-hydrogel soft contact lens. Methods: Three eyes from three patients with unresponsive corneal ulcers were included. A clot of PRP was applied directly onto the corneal ulcer and covered with a soft contact lens. The primary outcome was corneal healing. Changes in corneal ulcer area were measured by analyzing slit-lamp photographs taken using ImageJ software. Results: Successful corneal healing was achieved in all patients within two weeks, with no recurrences or signs of infection through the last follow-up. In two of the three cases, treatment was applied twice. Conclusions: This novel procedure was easy to perform, economically advantageous, and a possible alternative to surgical approaches for enhancing epithelial wound healing in patients with non-healing corneal ulcers. Further prospective and comparative studies are needed to assess the efficacy of this treatment.

Change in the geometry of positive- and negative-powered soft contact lenses during wear.

Contact lens wear causes mutual interactions between the ocular surface and the lens, which may affect comfort as well as vision. The aim of this study was to examine deformations in modern positive- and negative-powered silicone hydrogel soft contact lenses (SiH SCLs) after 7 days of continuous wear. This pre-post interventional study included 64 eyes: 42 eyes with myopia of -3.00 D and 22 eyes with hyperopia of +3.00 D. All patients underwent general ophthalmic examination, corneal topography/tomography, total corneal and epithelial thickness mapping, and specular microscopy before and after the wearing period. SiH SCLs made of senofilcon A were worn continuously for 7 days on all eligible eyes. The geometry of the new and used lenses was measured 3 to 6 minutes after removal in two perpendicular planes using a custom-made swept source optical coherence tomography (SS-OCT) system for in vitro measurements. The anterior and posterior radii of curvature decreased in -3.00 D lenses in two perpendicular planes. This effect correlated significantly with average keratometry of the cornea. Sagittal lens height was lower in +3.00 D lens after wear, which correlated moderately with the corneal sagittal height. A significant decrease in central corneal epithelial thickness was observed after wearing +3.0 D lenses. In conclusion, SiH SCLs made of senofilcon A undergo minor deformations after 7-day continuous wear. Geometry modifications are different for -3.00 D and +3.00 D lenses, and they imitate the shape of the anterior eye surface. These geometric changes are accompanied by a decrease in the central thickness of corneal epithelium after +3.00 D lens wear.

Amphiphilic polymer co‐networks: 32 years old and growing stronger – a perspective

AbstractThis brief perspective overviews amphiphilic polymer co‐networks (APCNs), polymeric chemically crosslinked hydrogels also covalently hosting a hydrophobic segment, conferring upon these materials the important property of internal self‐organization in aqueous environments. APCN synthesis is most conveniently accomplished via the random crosslinking copolymerization of a hydrophilic monomer with a hydrophobic macro‐crosslinker, whereas better structures are attained via the end‐linking of amphiphilic linear ABA triblock copolymers or amphiphilic star diblock copolymers. Microphase‐separated morphologies, translucency‐to‐transparency, biocompatibility, low to moderate aqueous swelling, fair mechanical strength and possible stimulus‐responsiveness constitute the main physicochemical properties of APCNs, with their major commercial application being in silicone hydrogel soft contact lenses. Modeling the swelling, morphological and mechanical behavior of these intriguing materials is an area where more progress is necessary in order to improve our understanding of these networks and facilitate the design of next‐generation APCNs. © 2020 Society of Industrial Chemistry

Evaluation of In Vitro Wettability of Soft Contact Lenses Using Tear Supplements

To evaluate the interaction between tear supplements and soft contact lenses (SCLs), we measured the contact angles (CAs) on the SCLs using commercially available tear supplements. We used four daily disposable conventional hydrogel lenses (etafilcon A, etafilcon A+ polyvinylpyrrolidone, nelfilcon A, and omafilcon A containing 2-methacryloyloxyethyl phosphorylcholine [MPC]) and four silicone hydrogel lenses (narafilcon A, senofilcon A, delefilcon A, and stenfilcon A). The CAs on the SCLs were measured using a sessile drop technique and four different types of sessile drops, including saline, artificial tears, lubricants containing 2-MPC (MPC solution), and 0.1% hyaluronate acid (HA). The CA values associated with the silicone hydrogel lenses were significantly (P<0.001) lower than those associated with the conventional hydrogel lenses with all four solutions. The mean CA of 0.1% HA was significantly (P<0.01) higher than that of saline. The mean CA of the MPC solution was significantly (P<0.01) lower than that of saline with the conventional hydrogel lenses but significantly (P<0.05) higher than that of saline with the silicone hydrogel lenses. The CAs associated with the silicone hydrogel SCLs were higher with the use of the MPC solutions and HA in vitro. The measured CAs may depend on ingredient agents, surface treatment of the CLs, and components of the tear supplements.

Validation and reliability of the Turkish version of Contact Lens Dry Eye Questionnaire-8 (CLDEQ-8)

PurposeContact lens dry eye questionnaire-8 (CLDEQ-8) quantifies the disturbing symptoms with the aim of assessing the satisfaction and overall opinion of contact lens wearers. The aim of this study was to develop Turkish version and to evaluate the validity and reliability of the questionnaire. MethodsCLDEQ-8 was translated into Turkish language, using the back translation methods. In a sample of 10 individuals, validation of translation was checked as pre-test evaluation. Turkish version of CLDEQ-8 questionnaire was conducted in 100 soft contact lens wearers. Validity was investigated using Rasch analysis and reliability by Cronbach’s alpha (α) and person separation index (PSI). ResultsThe participants were healthy other than refractive errors. Their mean age was 25.19 ± 7.03 years and male to female ratio was 14/86. All of them were silicone-hydrogel soft contact lens wearers. Their contact lens history was 3.13 ± 3.77 years and mean refraction error was -2.69 ± 1.64 diopters.The whole 8 items were consistent with the Rasch model (p > 0.05) and unidimensional (paired t test, p = 0.1). Both Cronbach’s alpha and PSI values were higher than 0.7 (α = 0.873, PSI = 0.867). There were not functional differences in questionnaire items regarding overall age groups (Andersen LR test, p = 0.518). ConclusionTurkish version of the CLDEQ-8 conforms to the Rasch model and provides the one dimensional assumption. The questionnaire has internal consistency, is valid and reliable in Turkish contact lens wearers.

Performance and Safety of Silicone Hydrogel Soft Contact Lenses

Performance and Safety of Silicone Hydrogel Soft Contact Lenses

Влияние препарата «Катионорм» на слезную пленку при обструктивной дисфункции мейбомиевых желез у пользователей мягких контактных линз

There are more than 80 million users of soft contact lenses in the world - 10-15 % of the population. The prevalence of meibomyus gland dysfunction is 43-61 % with the prevalence of obstructive form and the development of lipodeficiency in lacrimal film. At the same time, the use of traditional tear substitutes based on hyaluronic acid is ineffective and the problem of finding a tear substitute with exposure to all 3 layers of lacrimal film becomes relevant. Nanoemulsion “Cationorm” is created as a means of pathogenetic therapy of dry eye syndrome against the background of lipodeficiency, however, there weren't any studies of its effectiveness in obstructive form of meibomyus gland dysfunction among users of soft contact lenses. We examined 3 layers of lacrimal film with the help of Norn's sample with determination of time of lacrimal film break, bio-measurement of lacrimal meniscus and biomicoscopy of eyelid edge region at painting of lissamino-om green. The study involved 28 young carriers of silicone-hydrogel contact lenses with signs of obstructive form of meibomyus gland dysfunction, who we divided into two groups: a control group used to eliminate the symptoms of a hyaluronic acid-based tear substitute, and an experimental group using the drug “Cationorm”. We revealed prolonged effect of nanoemulsion “Cationorm” on all three layers of lacrimal film, which hasn't only symptom lacrimal, but has pathogenetic therapeutic delayed effect among users of soft contact lenses with obstructive form of dysfunction of meibomyum glands, and nanostimer of lipid microspheres provides full compatibility even with material of silicone-hydrogel soft contact lenses. We proved the protective effect of the preparation on ocular epithelium cells.

Oxidative stress correction in the treatment of severe keratoconjunctivitis sicca in patients with Sjorgen's syndrome

To evaluate the antioxidative effect of artificial tears in the treatment of keratoconjunctivitis sicca (KCS). The study included 43 patients (60 eyes) with severe KCS: 38 women (50 eyes) and 5 men (10 eyes) aged from 27 to 76 years (in average 52 years). Patients were randomly divided into 2 groups; all patients used therapeutic silicone hydrogel soft contact lens (SCL) and instillations of 0.05% Cyclosporin A (CyA) 2 times a day. Patients of the first group (22 people, 30 eyes) used 0.15% hyaluronic acid. In the second group, patients (21 people, 30 eyes) used a tear substitute with similar surface-active component, but with antioxidant properties. The results of the treatment were evaluated using basic and additional research methods at 1, 3, 6 and 12 months. Corneal epithelialization was achieved after 1 month of conservative treatment in all patients who wore SCLs and were treated with instillations of 0.05% CyA and artificial tears. Then the lenses were removed and the patients were switched to instillations of CyA and artificial tears. Comparative analysis of the results showed that higher functional indicators were achieved in the second group, where patients used Artelac Rebalance drops with antioxidant properties. Improvement of clinical and functional parameters in the treatment of severe forms of KCS was achieved by direct action on both links of pathogenesis with minimal amounts of the drugs and the frequency of their use. Subsequent supportive therapy contributed to stabilization of the results and further increase of the functional parameters.

Changes in accommodative micro-fluctuations after wearing contact lenses of different optical designs

Purpose: It has been postulated that eye fatigue symptoms associated with use of digital devices may be a result of ciliary muscle stress. Accommodative micro-fluctuations (AMF) are caused by ciliary muscle vibrations related to ciliary muscle stress during accommodation. Contact lenses with innovative optical designs may reduce AMF. The objective of this study was to evaluate changes in AMF in subjects wearing silicone hydrogel soft contact lenses with two different optical designs.