Silicone Hydrogel Contact Research Articles

Enhancing Performance of Silicone Hydrogel Contact Lenses with Hydrophilic Polyphenolic Coatings

This study explores the application of a dopamine-assisted co-deposition strategy to modify the surface of daily disposable silicone hydrogel contact lenses. Aiming to enhance the hydrophilicity of these typically hydrophobic lenses, we developed an industry-friendly process using simple dip coating in aqueous solutions. By co-depositing tannic acid, dopamine and chitosan derivative and employing periodate oxidation, we achieved a rapid and efficient coating process. High-molecular-weight branched polyethylene imine was introduced to promote surface reactions. The resulting lenses exhibited extreme hydrophilicity and lipid repellency without compromising their intrinsic properties or causing cytotoxicity. While the coating demonstrated partial antimicrobial activity against Gram-positive Staphylococcus aureus, it offers a foundation for the further development of broad-spectrum antimicrobial coatings. This versatile and efficient process, capable of transforming hydrophobic contact lenses into hydrophilic ones in just 15 min, shows significant potential for improving comfort and performance in daily disposable contact lenses.

Analysis of Deposition and Diffusion of Cholesterol in Silicone Hydrogel Contact Lenses Using Confocal Microscopy.

In this study, we investigated lipid deposition and diffusion in silicone hydrogel (Si-Hy) contact lenses using confocal microscopy. Different Si-Hy lenses were analyzed to understand the interaction patterns of cholesterol with various lens materials. The results highlight significant differences in the deposition and diffusion of lipids through the lenses, revealing that some materials, such as comfilcon A, allow lipids to diffuse more freely compared to others, such as samfilcon A, which provides a greater barrier. The study also observed different morphology and movement of lipid agglomerates across the lenses and above it surfaces. These findings contribute to the understanding of lipid-lens interaction, which is important for the development of lenses with improved comfort and functionality. The research highlights the importance of considering lipid interactions in the design and selection of Si-Hy contact lenses to enhance wearer comfort and lens performance.

International trends in prescribing silicone hydrogel contact lenses for daily wear (2000–2023): An update

PurposeIntroduced around the turn of the 21st century, silicone hydrogel contact lenses alleviated hypoxic anterior eye complications due to their high oxygen transmissibility. The purpose of this work is to update earlier surveys by describing international trends in silicone hydrogel daily wear contact lens fitting between 2000 and 2023. MethodAn annual contact lens prescribing survey was sent to eye care practitioners in up to 71 countries between 2000 and 2023. Data relating to 260,144 daily wear soft contact lens fits undertaken in 20 countries returning reliable longitudinal data were analysed in respect of silicone hydrogel daily wear contact lens fitting. ResultsThere has been a dramatic increase in silicone hydrogel daily wear lens fits (p < 0.0001), increasing from 2.8 % of all daily wear soft lens fits in 2000 to 73.7 % in 2023. Of all daily wear soft contact lenses prescribed to males, 44.6 % were silicone hydrogel lenses, compared with 43.5 % for females (p = 0.0146). The mean age of those wearing silicone hydrogel daily wear lenses was 32.0 ± 14.5 years, compared to 30.4 ± 13.6 years for those wearing daily wear hydrogel lenses (p < 0.0001). Between 2019–2023, the average percentage of fits was – (a) material type: silicone hydrogel – 73 %; mid-water content hydrogels – 13 %; high water content hydrogels – 9 %; and low water content hydrogels – 5 %, and (b) lens design: spherical – 44 %, toric – 32 %, multifocal – 17 %, monovision – 4 %, and ‘other’ – 3 %. ConclusionThe dramatic increase in silicone hydrogel contact lens prescribing for daily wear has been commensurate with the introduction of multiple lens brands and an ongoing expansion of lens designs, parameters and replacement frequency options. The balance between silicone hydrogel and hydrogel lens prescribing is perhaps starting to approach an equilibrium.

Kontaktlinsenversorgung bei ausgeprägter Sicca bei vermuteter Alakrimie bei einem sechsjährigen Kind

Purpose. The aim of this case report is to describe a case of suspected alacrimia in a six-year-old child that resulted in irregular astigmatism with risk of amblyopia. A specialty contact lens fitting for visual rehabilitation was performed. Material and Methods. Different wearing modes (extended wear and daily wear) as well as contact lens types (soft silicone hydrogel contact lenses of different wearing rhythms, as well as rigid gas permeable (RGP) contact lenses were fitted. Results. In this case, different contact lens types (soft and rigid contact lenses) could not achieve a satisfactory treatment result. However, a piggyback contact lens system with daily wear was a good treatment solution. Conclusion. Irregular astigmatism in children is always a high risk of amblyopia. For this reason, timely optical treatment for visual rehabilitation is a high priority. Sometimes it is necessary to combine different contact lenses and wearing modalities to achieve the best solution for a complex treatment situation. Keywords: ALACRIMIA, HYPOLACRIMIA, SICCA, IRREGULAR ASTIGMATISM, VISUAL REHABILITATION, AMBLYOPIA RISK

Drug-impregnated contact lenses via supercritical carbon dioxide: A viable solution for the treatment of bacterial and fungal keratitis

Keratitis is a corneal infection caused by various bacteria and fungi. Eye drop treatment of keratitis involves significant challenges due to difficulties in administration, inefficiencies in therapeutic dosage, and frequency of drug applications. All these are troublesome and result in unsuccessful treatment, high cost, time loss, development of drug resistance by microorganisms, and a massive burden on human health and the healthcare system. Most of the antibacterial and antifungal medications are non-water-soluble and/or include toxic drug formulations. Here, the aim was to develop drug-loaded contact lenses with therapeutic dosage formulations and extended drug release capability as an alternative to eye drops, by employing supercritical carbon dioxide (ScCO2) as a drug impregnation solvent to overcome inefficient ophthalmic drug use. ScCO2, known as a green solvent, has very low viscosity which provides high mass transfer power and could enhance drug penetration into contact lenses much better with respect to drug loading using other solvents. Here, moxifloxacin (MOX) antibiotic and amphotericin B (AMB) antifungal medicines were separately loaded into commercially available silicone hydrogel contact lenses through 1) drug adsorption from the aqueous solutions and 2) impregnation techniques via ScCO2 and their efficacies were compared. Drug impregnation parameters, i.e., 8–25 MPa pressure, 310–320 K temperature, 2–16-hour impregnation times, and the presence of ethanol as polar co-solvent were investigated for the optimization of the ScCO2 drug impregnation process. The highest drug loading and long-term release kinetic from the contact lenses were obtained at 25 MPa and 313 K with 2.5 h impregnation time by using 1 % ethanol (by volume). Furthermore, antibacterial/antifungal activities of the MOX- and AMB-impregnated contact lenses were effective against in vitro Pseudomonas aeruginosa (ATCC 10145) bacteria and Fusarium solani (ATCC 36031) fungus for up to one week. Consequently, the ScCO2 method can be effectively used to impregnate commercial contact lenses with drugs, and these can then be safely used for the treatment of keratitis. This offers a sustainable delivery system at effective dosage formulations with complete bacterial/fungal inhibition and termination, making it viable for real animal/human applications.

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.

Assessment of large-diameter and small-diameter SoftK specialty contact lenses for early-stage keratoconus.

Soft contact lenses may be a good alternative for early-stage keratoconus (KC) patients who do not tolerate rigid gas permeable (RGP) lenses due to ocular discomfort or complications. This prospective study compared outcomes obtained after 2 weeks of wearing two types of soft silicone hydrogel contact lenses for keratoconus that varied in their diameter and central thickness (cc). Patients with Amsler-Krumeich grades I or II KC were fitted with small-diameter (14.2 or 14.8 mm) SoftK (SD-SoftK, cc = 0.48 mm) and large-diameter (17 mm) SoftK (LD-SoftK, cc = 0.60 mm) lenses, each worn for 2 weeks in a crossover design. Low (10%;10VA) and high (100%;100VA) contrast visual acuity, contrast sensitivity (CS, Pelli-Robson), higher order aberrations (HOAs, Visionix Vx130), the number of trial lens modifications during fitting and the subjectively preferred lens were compared using Friedman tests with post-hoc analysis. Forty eyes (N = 20, 10 males, mean age: 39.0 ± 9.9 years, range: 23-55 years) were examined. Their habitual median (interquartile1, interquartile3) 10VA (LogMAR), 100VA (LogMAR) and CS (LogCS) were 0.52 (0.30, 0.50), 0.14 (0.10, 0.15) and 1.35 (1.35, 1.50), respectively. For the SD-SoftK condition, the values were 0.23 (0.17, 0.30), 0.02 (0.00, 0.05) and 1.50 (1.50, 1.65), respectively. For the LD-SoftK condition, the respective values were 0.36 (0.27, 0.44), 0.09 (0.05, 0.13) and 1.50 (1.50, 1.60). SD-SoftK lenses significantly improved 10VA compared with habitual and LD-SoftK. SD-SoftK also significantly improved CS compared with habitual, but not LD-SoftK. LD-SoftK significantly improved spherical aberration compared with uncorrected (0.03 ± 0.10 μ vs. 0.07 ± 0.13 μ) but not SD-SoftK (0.04 ± 0.07 μ). Both lenses required a mean of 1.5 modifications prior to final lens fitting. Fewer adverse events were seen with SD-SoftK (N = 3) compared with LD-SoftK (N = 8), and 75% of participants preferred SD-SoftK lenses. SD-SoftK lenses were preferred by 75% of subjects, were associated with fewer adverse events and significantly improved 10VA compared with LD-SoftK lenses. SD-SoftK lenses also significantly improved CS compared with the habitual correction, but this did not differ significantly from the LD-SoftK lenses.

Assessing neophyte response to daily disposable silicone hydrogel contact lenses: A randomised clinical trial investigation over one month.

This randomised clinical trial assessed the impact on symptoms, tear film dynamics and ocular surface integrity of daily disposable silicone-hydrogel contact lenses (CLs) over a month, paying special attention to lid wiper epitheliopathy (LWE) and its implications for CL discomfort. Neophyte CL wearers (n = 44, 21.09 ± 5.00 years old) were randomly assigned to either the experimental (n = 24) or control group (n = 20). Participants assigned to the experimental group were required to wear daily disposable CLs for 1 month for at least 8 h/day and 6 days/week. All participants were healthy subjects (no history of ocular surgery or active ocular disease) with spherical refractive errors between -8.00 and +5.00 D and cylindrical power <0.75 D. At the baseline and 1-month sessions, the Dry Eye Questionnaire 5 (DEQ-5) was completed, together with the measurement of tear film osmolarity with the TearLab osmometer, tear meniscus height (TMH) and lipid layer pattern (LLP) using a slit-lamp with Tearscope Plus attached, fluorescein break-up time (FBUT), maximum blink interval (MBI), corneal staining with fluorescein under cobalt blue light and LWE with lissamine green under slit lamp and halogen white light. At the baseline session, LWE showed a negative correlation with DEQ-5 (r = -0.37, p = 0.02). Significant differences in FBUT and LWE (p = 0.04) and a positive correlation between LWE and DEQ-5 (r = 0.49, p = 0.007) were observed at 1 month. Intrasession analysis at 1 month showed significant differences between the experimental and control groups in DEQ-5, FBUT and LWE (all p ≤ 0.02). Intersession analysis in the experimental group showed variations in DEQ-5, FBUT and LWE (all p ≤ 0.02) but no significant variation in the control group (all p ≥ 0.11). The presence of LWE was significantly correlated with higher symptom values in the DEQ-5. Also, participants in the experimental group presented higher values of LWE after 1 month of CL wear, in comparison with the control group.

Myopie-Management vom Kind zum Erwachsenen anhand eines Fallberichts

Purpose: The case report describes the successes and lessons learned from optical therapeutic management of progressive myopia, based on long-term treatment plan and the resulting development of the correction and axial lengths of a female patient from age 8 to 22 years. Material and Methods: Using a risk analysis and adaptive care plan, with age-appropriate contact optic care, an attempt was made to positively inhibit, the progression of myopia in a young female patient from 2009 to 2023. The scientific facts and contact lens techniques available at the time of treatment, were applied such as analysis of environmental factors, use of bifocal silicone hydrogel contact lenses and orthokeratology. Results: By using orthokeratology contact lenses, the increase in myopia and axial length growth could be clinically inhibited over several years. Early setbacks during the treatment period due to ineffective measures or early treatment cessation (partial rebound effect) could be stopped or stabilized due to the increasing age of the patient. Conclusion: By means of targeted and controlled contact lens treatment, it is possible to successfully inhibit the progression and thus mitigate the subsequent, secondary health risk.

Evaluation of mucin changes between daily and extended wear silicone hydrogel contact lenses

Background: Initially, contact lenses were recommended only for daily wear because of infection and discomfort concerns. With rising demand, particularly for overnight use, extended wear lenses have gained significance. Despite concerns, intensive development of materials like Lotrafilcon B aims to meet this demand, focusing on comfort and safety.Aim: This study aimed to evaluate the mucin quantity and quality changes between daily and extended wear (Lotrafilcon B), impacting eye health and comfort.Setting: The study was conducted at Kirana Eye Center, Cipto Mangunkusumo Hospital, Jakarta, Indonesia.Methods: This study was a single-blinded randomised clinical trial with two parallel groups. Forty (40) eligible subjects willingly participated. Mucin 5AC (MUC5AC) and Ferning-type tests were conducted. The 40 subjects with moderate myopia were then divided into a daily wear and an extended wear group. The MUC5AC test was performed at pre-fitting and at 4 weeks, whereas the Ferning-type tests were taken at pre-fitting and 1st and 4th weeks.Results: For both groups, there was a significant increase in MUC5AC levels from pre-fitting to week four, but with no significant difference between them in final MUC5AC levels. Additionally, the comparison of eyes with normal and abnormal Ferning-types between the two groups showed no significant differences at pre-fitting, 1st and 4th weeks.Conclusion: There is no significant difference in MUC5AC levels with the use of daily or extended wear (with Lotrafilcon B).Contribution: This study compares the impact of daily and extended wear Lotrafilcon B contact lenses on eye health and comfort in moderate myopia patients.

Contact lenses in paediatric aphakia in the Netherlands; A multicentre retrospective chart study

PurposeThe main aim of this study was to evaluate the type, parameters, loss and complications of contact lenses (CLs) in the treatment of paediatric aphakia over a 10-year period. MethodsThis retrospective multicentre chart review included the files of aphakic CL wearers under the age of 9 years old that were treated between 2008 and 2018. Patients with traumatic aphakia and scarring of the cornea were excluded. The following data were collected; demographic data, cataract type (congenital or secondary), CL type, parameters and wearing time, reason for replacement and discontinuation of the CLs, visual acuity (VA), prophylactic use of antibiotics (ABs), and complications. ResultsNinety-one aphakic children (132 eyes) were fitted with soft CLs. The median age of cataract extraction was 10.50 weeks (interquartile range (IQR) 7,15) in the congenital cataract group and 112 weeks (IQR 41,285) in the secondary cataract group. At the initial fitting a silicone elastomer CL was fitted in 86 % and a silicone hydrogel CL in 12 %, the remaining 2 % were mixed CL types. The median CL power at baseline was + 29 D (IQR 25,32) and after 3 years of wear the median power had shifted significantly to + 20 D (IQR 17,26), P < 0.001. A total of 1083 extra CL replacements were needed of which 414 in the first year of wear. Of these 414 replacements almost half (46 %;n = 191) were due to loss of the CL. Complications developed in 8 (9 %) cases and 7 (8 %) patients discontinued CL wear. ConclusionThis paper confirms that paediatric aphakia can be successfully treated with soft CLs with low rates of complications and discontinuation encountered. Unscheduled CL replacements due to loss are a concern, especially in the first year, and are straining for both the care giver and medical system. Attentive care and clear information is advised during the first year of CL wear.

In-vitro dehydration kinetics coefficient of Kalifilcon A and other contact lens materials

In contact lens (CL) wear, dehydration needs to be tailored to avoid dryness and related symptoms. In this view, this work aims to assess and compare the in-vitro dehydration kinetics of five CL materials, including the newly developed Kalifilcon A CL. At 36 °C and 60% relative humidity, the in-vitro dehydration kinetics of the different CLs were compared using a gravimetric method. CLs were analyzed either after a rinse of a few seconds in preservative-free saline solution or after a 24-h incubation in the same solution. A model based on the Fick diffusion equation was employed to deduce a water kinetics coefficient, providing insights into water diffusion within the polymeric matrix. The study reveals that all materials exhibit a non-Fickian dehydration behavior, with significant differences in dehydration kinetics coefficients and dehydration rate slopes. Etafilcon A and Omafilcon A, both hydrogel CLs, exhibit a similar behavior, different compared to the pattern shown by Senofilcon A and Delefilcon A, silicone-hydrogel CLs. Notably, Kalifilcon A, despite being a silicone-hydrogel, displays a hydration behavior reminiscent of hydrogel CLs.

Ocular effects of exposure to low-humidity environment with contact lens wear: A pilot study.

To compare the ocular effects of exposure to a low-humidity environment with and without contact lens (CL) wear using various non-invasive tests. Fourteen habitual soft CL wearers were exposed to controlled low humidity (5% relative humidity [RH]) in an environmental chamber for 90 min on two separate occasions. First, when wearing their habitual spectacles and then, on a separate visit, when wearing silicone hydrogel CLs that were fitted specifically for this purpose. All participants had adapted to the new CL prior to data collection. Three non-invasive objective measurements were taken at each visit: blinking rate, objective ocular scatter (measured using the objective scatter index) and ocular surface cooling rate (measured using a long-wave infrared thermal camera). At each visit, measurements were taken before the exposure in comfortable environmental conditions (RH: 45%), and after exposure to environmental stress (low humidity, RH: 5%). CL wearers showed increased blinking rate (p < 0.005) and ocular scatter (p = 0.03) but similar cooling rate of the ocular surface (p = 0.08) when compared with spectacle wear in comfortable environmental conditions. The exposure to low humidity increased the blinking rate significantly with both types of corrections (p = 0.01). Interestingly, ocular scatter (p = 0.96) and cooling rate (p = 0.73) were not significantly different before and after exposure to low humidity. There were no significant two-way interactions between correction and exposure in any of the measurements. CLs significantly increased the blinking rate, which prevented a quick degradation of the tear film integrity as it was refreshed more regularly. It is hypothesised that the increased blinking rate in CL wearers aids in maintaining ocular scatter quality and cooling rate when exposed to a low-humidity environment. These results highlight the importance of blinking in maintaining tear film stability.

In Vitro Evaluation of Soft Contact Lens Wettability With a Nonmodified Commercial Videokeratoscope.

To evaluate a new in vitro technique for measuring soft contact lens wettability using a nonmodified commercial videokeratoscope, the Medmont E300. To this end, the capability of different artificial tears containing hyaluronic acid (HA) to improve soft contact lens wettability in vitro was investigated. An experimental in vitro study was conducted to assess the wetting properties of three artificial tears containing different concentrations of HA (0.1%, 0.2%, and 0.3%) on soft contact lenses. A saline solution was used as the control. For each solution, 15 hydrogel (Ocufilcon D) contact lenses and 15 silicone-hydrogel (Somofilcon A) contact lenses were evaluated. The in vitro wettability of the lenses was measured using the Medmont E300 with a self-developed technique, which involved measuring the tear film surface quality (TFSQ) mean, TFSQ area, TFSQ central, and TFSQ inferior. Compared with the saline solution, all the concentration of HA (0.1%, 0.2%, and 0.3%) improved the in vitro wettability of both soft contact lenses by decreasing their TFSQ mean and TFSQ area ( P <0.05). Regression models revealed an exponential relationship between contact lens wettability and the concentration of HA for both soft contact lenses ( R >0.5, P <0.05). Furthermore, the hydrogel contact lens presented a wetter surface than the silicone-hydrogel contact lens ( P <0.05). The measurement of in vitro wettability of soft contact lenses with a nonmodified Medmont E300 seems to be a useful technique to evaluate the wetting properties of contact lens products.

Revolutionizing contact lens manufacturing: exploring cutting-edge techniques and innovations for enhanced vision and comfort

Abstract This review paper delves into the advancements and innovations revolutionizing contact lens (CL) manufacturing, focusing on techniques and technologies aimed at improving vision quality and wearer comfort. The article begins by tracing the evolution of CL fabrication techniques, paying homage to Leonardo da Vinci’s early contributions. It then discusses traditional methods such as lathe-cutting, spincasting, molded lens fabrication, and the recent advent of 3D printing in CL production. The review further explores advanced CL designs, including spherical, aspheric, toric, and bifocal/multifocal CLs, highlighting their specific applications and benefits. Material innovations in lens manufacturing are examined, with an emphasis on silicone hydrogel CL, hybrid lenses combining different materials, and the development of biocompatible and gas-permeable (GP) materials. Evaluation of optical design efficiency is another crucial aspect covered in this paper, encompassing visual acuity, contrast sensitivity, through-focus curves, reading performance, peripheral refraction, and patient-reported outcomes for quality of vision. Additionally, the role of nanotechnology and surface modifications in enhancing lens properties is explored, along with advances in lens coating and surface treatments, including antimicrobial and UV protection coatings. Nanocomposites of polymethyl methacrylate (PMMA) and TiO2 showed refractive indices between 1.52 and 1.59, while combining TiO2 NPs with poly(2-hydroxyethyl methacrylate) (PHEMA) yielded values ranging from 1.47 to 1.53. PGMA-TiO2 nanocomposites exhibited refractive indices between 1.47 and 1.50. Furthermore, nanocomposites of PVP-PVA-Ag with silver (Ag) NPs achieved higher refractive indices within the range of 1.45 to 1.49. This article concludes by discussing the challenges and future directions in CL manufacturing, focusing on addressing lens discomfort, improving oxygen permeability and moisture retention, and enhancing manufacturing efficiency and scalability. Overall, this review offers valuable insights into the cutting-edge techniques and innovations transforming CL production and paving the way for improved vision correction and wearer satisfaction.

Patient Satisfaction and Tear Film Break-Up Time After First-Time Wearing of Silicone Hydrogel Contact Lenses.

The dryness and discomfort associated with soft contact lenses (SCLs) prevent their continued use. Recently, verofilcon A, a new daily disposable silicone hydrogel material SCL, was introduced, which has a high water content (surface water content of 80% or more) that overcomes the low water content drawback of silicone hydrogels. In this study, we evaluated the non-invasive tear break-up time (NIBUT) and comfort level in individuals wearing verofilcon A SCL for the first time. We enrolled 42 first-time SCL wearers, comprising 84 eyes. NIBUT was measured using the DR-1α® dry eye observation device at the state of the naked eye before SCL wear (baseline) and at one and four weeks after the first SCL wear. Additionally, we conducted a questionnaire survey during the fourth week to assess the comfort level (0-10) of SCL wear. Results:The NIBUT values were significantly higher at one week (10.8 ± 2.2 s, p<0.01) and four weeks (11.4 ± 2.2 s, p<0.01) after the first SCL wear than those at baseline (5.9 ± 2.0 s). Comfort level in SCL use was significantly higher at one week (9.0 ± 1.1, p<0.01) and four weeks (8.7 ± 1.2, p<0.01) than that at baseline (7.8 ± 1.8), and this level was higher regardless of the baseline NIBUT value. Prolonged BUT and increased comfort levels were observed in individuals wearing verofilcon A SCLs. Improvement in tear fluid retention was found to alleviate dry eye and discomfort, suggesting that verofilcon A may be a beneficial introductory lens for first-time SCL wearers.

Observation and assessment of the immediate use of a silicon hydrogel contact lens after transepithelial corneal cross linking: a prospective study

BackgroundTransepithelial corneal crosslinking (CXL) is a novel surgical approach for the treatment of keratoconus, which is a bilateral asymmetrical ophthalmological disease accompanied by progressive corneal ectasia. Silicon hydrogel (SiH) contact lenses have been extensively used in clinical ophthalmologic medicine, as a postoperative ophthalmological intervention. However, the ideal lens application duration after transepithelial CXL remains uncertain. Here, we aimed to investigate the effects and comfort of immediate corneal contact lens use after transepithelial CXL for keratoconus.MethodsIn this prospective study, 60 patients with keratoconus who underwent transepithelial CXL treatment were enrolled from September 2021 to January 2023 with a male:female ratio of 39:21, and an average age of 25.42 ± 5.47 years. The patients were divided randomly into two groups: group A contained 30 patients wearing silicone hydrogel contact lenses for 7 days postoperatively, and group B contained 30 patients wearing the same contact lenses for 3 days.Ten subjective ophthalmologic symptoms were surveyed by the patients, including pain, photophobia, foreign body sensation, tearing, burning, blurred vision, dry eyes, difficulty opening the eyes, astringency, and stinging. Ophthalmologic signs, including corneal edema and conjunctival congestion, were recorded by a single clinician on postoperative days 1, 3, and 7.ResultsEach surgical procedure was readily performed without complications, and both groups postoperative day 7 (P = 0.04), where group B scored (0.01 ± 0.41) lesser than group A (0.12 ± 0.29), whilst corneal edema in both groups recorded significantly different on postoperative days 5 and 7 (group A demonstrated the result of 0.17 ± 0.14 and 0.08 ± 0.11 for the respective days, whereas group B indicated 0.10 ± 0.13 and 0.03 ± 0.07 at the corresponding times).ConclusionsImmediate use of silicone hydrogel corneal lenses after transepithelial CXL effectively alleviates postoperative ocular distress, particularly with a three-day use period as the ideal duration.

Association of ocular surface and meibomian gland alterations with silicone hydrogel contact lens wear

PurposeTo evaluate silicone hydrogel contact lens (SH-CL) effects on the meibomian glands, corneal structure, and ocular surface parameters. MethodsFifty SH-CL wearers for at least 6 months, and 50 sex and age-matched control subjects were recruited for this cross-sectional study. Visual display terminal (VDT) work and CL wear duration were questioned, ocular surface and tear functions were evaluated using OSDI questionnaire, tear break-up time (TBUT), corneal fluorescein staining, and Schirmer test. Corneal sensitivity was measured with Cochet-Bonnet aesthesiometry. Meibography and in vivo confocal microscopy (IVCM) were performed to evaluate meibomian glands and corneal structure. Intergroup comparisons were made using the Chi-square test, Wilcoxon test, or Kruskal–Wallis test. ResultsIn the CL group, TBUT was shorter (P = 0.01), corneal fluorescein staining (P = 0.04), OSDI scores (P < 0.001), and meiboscores (P < 0.001) were higher than the control group. The biomicroscopic evaluation revealed meibomian gland dysfunction (MGD) in 34 % of the CL group and 20 % of the control group, which was not statistically significant (P > 0.05). IVCM showed that endothelial cell density was lower (P = 0.01) and polymegethism was higher (P < 0.001) in the CL group. Subbasal nerve density and corneal sensitivity measurements were similar in the two groups (P > 0.05). The longer VDT work duration was associated with increased CFS in the CL group (P = 0.05). ConclusionThe results showed that SH-CL wear increased dry eye symptoms and ocular discomfort, especially in longer VDT work duration. Meibography revealed significantly worse results in SH-CL wearers. SH-CL-related ocular discomfort seems to be more associated with MGD rather than neurosensorial alterations.

고함수율의 셀룰로오스 표면층을 갖는 실리콘 하이드로젤 콘택트렌즈의 제조 및 물성

고함수율의 셀룰로오스 표면층을 갖는 실리콘 하이드로젤 콘택트렌즈의 제조 및 물성

Optical Quality and Visual Performance With Different Toric Contact Lens Designs.

To evaluate the optical quality of different toric contact lens (CL) designs and compare their on-eye visual correction performance. Twenty soft CL wearers aged 20 to 39 years were enrolled. Two daily disposable silicone-hydrogel toric CLs were tested: the "Eyelid Stabilized Design" (ESD-CL) and prism-ballast design (PB-CL); a spherical daily disposable silicone hydrogel CL (spherical CL) was used as a control. On-eye performance was compared for corrected distance visual acuity (CDVA), astigmatism, and ocular higher-order aberrations (HOAs); astigmatism and ocular HOAs were measured with a wavefront sensor. The subjective quality of vision, rated for "blurred vision" and "double vision," lens rotation, and fitting were also compared. The ESD-CLs, PB-CL, and no-CL provided better CDVA than spherical CL ( P <0.05). Compared with spherical CL and no CL, PB-CL and ESD-CLs caused significantly lesser astigmatism ( P <0.05). Coma was significantly lesser with ESD-CLs than that with PB-CL ( P <0.05); total HOAs did not differ among the four conditions. The subjective ratings for blurred and double vision were significantly lower with ESD-CLs than those with spherical CL ( P <0.05). Toric CLs provide a better CDVA than spherical CLs. However, differences in coma and subjective symptoms may occur because of the design of toric CLs.