Soft Contact Research Articles

Soft-stable interface in grasping multiple objects by wiring-tension

Efficiently manipulating objects in a group state poses an emerging challenge for soft robot hands. Overcoming this problem necessitates the development of hands with highly stable structures to bear heavy loads and highly compliant designs to universally adapt to various object geometries. This study introduces a novel platform for the development of robot hands aimed at manipulating multiple objects in each trial. In this setup, the objects come into soft contact with an elastic wire affixed to the finger skeletons. This combination results in a harmonious hybrid finger, inheriting both the soft, flexible properties of the wire and the robust stability provided by the finger skeleton. To facilitate this approach, a theoretical model was proposed to estimate the kinematics of manipulating multiple objects using wiring-based fingers. Based on this model, we designed a hybrid gripper comprising two wiring-based fingers for conducting experimental evaluations in manipulating four groups of samples: a pair of bevel gears, a pair of bevel gears plus a pneumatic connector, a pair of glue bottles, and a pair of silicon bottles. The experimental results demonstrated that our proposed gripper reached good performance with high success rates in durability tests conducted at various lifting velocities and high adaption with objects in soft-friendly ways. These findings hold promise for efficiently manipulating multiple complex objects in each trial without the need for complex control systems.

Two-Year Myopia Management Efficacy of Extended Depth of Focus Soft Contact Lenses (MYLO) in Caucasian Children

To evaluate the progression of myopia as assessed by change in axial length (AL) and spherical equivalent (SE) from baseline in Caucasian children wearing extended depth of focus soft contact lenses (CLs) compared to distance single-vision spectacles. Prospective non-randomized comparative clinical trial. A total of 90 children (6-13 years of age) with SE ranging from -0.75 to -10.00 diopters (D) were recruited. Of these children, 45 were fitted with CLs (MYLO, mark´ennovy), whereas 45 children wore spectacles. Cycloplegic refraction was measured with an auto-refractometer (Topcon-TRK-2P) and AL with an IOLMaster-700 (Zeiss) at 6-month intervals. Subjective responses after 1 month of CL wear related to vision and comfort were determined using a questionnaire with a scale from 1 (very poor) to 10 (excellent). High-contrast visual acuity (HCVA) and contrast sensitivity (CS) were evaluated at baseline, 12, and 24 months. After 2 years, mean change in SE/AL in the CL group was -0.62 ± 0.30 D/0.37 ± 0.04 mm and -1.13 ± 0.20 D/0.66 ± 0.03 mm in the spectacles group (P < .001). Cumulative absolute reduction in axial elongation (CARE) was 0.29 ± 0.06 mm. Difference in SE change was -0.50 ± 0.34 D. Although 100% of CL group had an AL increase ≤0.50 mm, all participants increased ≥0.50 mm in the spectacles group. In all, 53% of the CL group and 1% in the spectacles group showed a progression in SE ≤ -0.50D. All questionnaire items showed a mean value ≥9. There was a reduction logMAR HCVA in the CL compared to the spectacles group but it was less than 1 line (P < .001). Use of MYLO CLs reduced axial elongation and myopia progression compared to use of distance single-vision spectacles.

Visual Performance of Two Designs of Myopia Management Soft Contact Lenses Compared with a Monofocal One in Young Adults.

To compare the visual performance of two distinct types of soft contact lenses (CL) aimed at slowing down myopia progression with the performance of a monofocal soft CL. In a prospective double-masked, crossover trial, 18 myopic adults (aged 18-30 years old) were fitted in a randomized order with three types of disposable CL: MiSight (dual-focus), Mylo (extended depth of focus -EDOF-), and Clariti (single distance vision). Measurements were taken after wearing the CL for five days with five days off in between at two different optometry centers. High contrast distance visual acuity (VA) with spectacles and for each of the different CL, subjective refraction, slit lamp exam, aberrometry, stereopsis, monocular and binocular amplitude of accommodation and accommodative facility, and horizontal phorias were measured. The high contrast distance VAwas better for the single vision CL compared to the myopia control CL. No significant differences were observed between the r two myopia control CL. The overall root mean square (RMS) was higher for the double focus CL (RMS = 1.18 0.29 µm), followed by the EDOF CL (RMS = 0.76 0.35 µm) and then the single vision CL (RMS = 0.50 0.19 µm). The primary spherical aberration (SA) mean value was low for all of the three CL, without statistical differences among them. No other significant differences were detected. The overall RMS resulted in a higher value for the dual-focus than the EDOF CL, but no differences in high contrast distance VA and binocularity were detected between them. The monofocal CL's performance was better than the myopia control CL.

Wear Experience with a daily disposable soft contact lens for astigmatism in current wearers of a reusable soft toric contact lens.

The purpose of this study was to evaluate the wear experience of satisfied wearers of a particular reusable toric soft contact lens when refit into a water surface technology daily disposable toric soft contact lens. 30 participants completed the study over three visits. At the first visit, subjects were refit into with their habitual reusable toric soft contact lens (comfilcon A) to maximize fit and vision. Subjects returned after one week and were then refit into the study daily disposable soft contact lenses (verofilcon A) and completed surveys of their initial impressions of comfort, vision, and satisfaction. Participants wore the study lenses for two weeks, and then returned for their final visit to complete a vision and ocular health check. At the final visit, subjects also completed surveys to rate their overall and end-of-day comfort, quality of vision, stability of vision, and dryness using a visual analog scale (VAS). Participants also answered questions about their wear experience with the lenses. Overall median and interquartile range (IQR) of all data and surveys was calculated. Initial impressions of the study lenses revealed a median (IQR) score of 85 (28) for vision, 91 (25) for comfort, and 87 (21) for satisfaction. Overall VAS scores after two weeks of wear found median scores of 93 (16) for quality of vision, 88 (28) for stability of vision, and 91 (20) for comfort. End-of-day median scores were 82(27) for quality of vision, 90 (35) for stability of vision, and 80 (38) for comfort. Overall dryness scores were 20(45) and end-of-day dryness was 39 (46). Median(IQR) binocular logMAR visual acuity with the study lenses was -0.16(0.1). Median rotation of the lenses was 0(4.3) degrees. Participants wearing the daily disposable study lenses for astigmatism gave high scores in vision and comfort both at initial fitting and after two weeks of lens wear. Results showed that satisfied wearers of comfilcon A reusable toric soft contact lenses can be successfully refit with verofilcon A daily disposable contact lenses.

Pros and Cons of soft contact lens power mapping

Purpose. To provide an overview of currently available meth- ods and instruments for the measurement of soft contact lens power maps, together with their advantages and potential shortcomings. Material and Methods. The three leading measurement prin- ciples of Moiré Fringe, Shack-Hartmann and Phase Shifting Schlieren were identified, and the relevant literature reviewed and technical specifications summarised. To demonstrate some of the potential deficiencies associated with optical power mapping, a series of measurements were conducted on toric, multifocal and extended depth of focus lenses, using one representative instrument. Raw measured data were analysed using various analysis tools and parameters. Results. Power maps and power profiles are presented for the various lens types. Different smoothing filter settings resulted in significantly different power profiles near the optical centre. The ‘Power versus Azimuth’ profiles showed unexpected results. Conclusion. While all three methods are generally reliable and easy to use, there are still some limitations which need to be considered when interpreting the results. In particular, the profile filter settings need to be chosen carefully for multifocal and extended depth of focus lenses. The need for accurate refractive index data for lens material and solution was demonstrated. Keywords Soft contact lenses, power maps, power profiles, Moiré Fringe, Shack-Hartmann, Phase Shifting Schlieren

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.

Effectiveness of toric soft contact lenses for vision correction in patients with different degrees of astigmatism: a real-world study.

To assess the visual correction of patients with different degrees of astigmatism with toric soft contact lenses (TSC). It was a real-world study with prospective and single-arm design. A total of 384 patients with astigmatism who came for TSC fitting and alignment from November 2022 to January 2023 were included. According to the difference in astigmatism, patients were divided into groups A (cylinder degree: -0.75 to -0.50 D), B (cylinder degree: -1.75 to -1.00 D) and C (cylinder degree ≤ -2.00 D), and followed up on the day of wear, 1wk, 1 and 3mo, mainly to observe visual acuity, refraction, lens fit, visual quality and comfort at 1wk after wear. The visual acuity success rate and the overall success rate of the fitting were evaluation indicators (taking into account the four dimensions of visual acuity, fitting, quality of vision and comfort). The visual acuity success rate was calculated by taking "corrected visual acuity with contact lenses is no less than 1 line or better than best spectacle-corrected visual acuity" (i.e. corrected visual acuity with contact lenses is 1 line below, equal to, one line above or more than best spectacle-corrected visual acuity) as the criterion for visual success, and the the overall success rate of the fitting was calculated by using the comprehensive indicators (visual acuity, fit, visual quality, comfort) to meet certain conditions as the judgment criteria for successful fitting. After 1wk of wearing TSC, the visual acuity success rates of patients were 100% (207/207), 98.58% (139/141) and 97.22% (35/36) in the three groups, respectively, with residual cylinder closed to 0. The acceptability of the lens fitting was over 95%; the incidence of adverse visual symptoms was within 10% and the comfort acceptability was over 97%. The overall success rate of fitting for patients with high, medium and low astigmatism was 93.72% (194/207), 90.78% (128/141) and 88.89% (32/36), respectively. TSC (model: G&G POP·CT) are effective in correcting astigmatism in patients with different degrees of astigmatism.

Ultra-low friction in soft contact lenses: Analysis of dynamic free responses measured by the dynamic oscillating tribometer

Friction coefficient is considered as a measurement for clinical comfort of soft contact lenses. One of the main challenges in the tribology field is to evaluate the friction in soft materials such as soft contact lenses. In this work, we aim to evaluate the friction at the eyelid-lens contact using a new technique. This technique is based on a single-degree-of-freedom (SDOF) mass-spring system having a sliding contact. The experimental technique measures the free responses of the mechanical system. The friction is then evaluated from the damped free responses with a high accuracy. A variety of soft contact lenses are tested with some lubricants under many physiological conditions. The results are discussed and compared with those in the literature.

Reliability and agreement of subjective and objective non‐invasive break‐up time measurements in contact lens wearers

AbstractPurposeTo assess the reliability and agreement of non‐invasive break‐up time (NIBUT) in symptomatic and asymptomatic contact lens (CL) wearers using automatic objective and conventional subjective techniques.MethodsIn this prospective cross‐sectional study, soft CL wearers, classified into symptomatic and asymptomatic based on the Contact Lens Dry Eye Questionnaire‐8, underwent NIBUT assessment with the CL in situ. The CA‐800 Corneal Analyzer and the EasyTear® VIEW+ Tearscope were used for objective and subjective evaluation, respectively. The within‐subject repeatability and intraclass correlation coefficient (ICC) were calculated. The agreement between the devices was compared using the Bland–Altman method.ResultsA total of 141 CL wearers (51 male and 90 female) with a mean age of 33.6 (SD = 12.2) years were included. The repeatability and ICC values obtained with the CA‐800 device when measuring NIBUT were 5.4 s and 58.6% across the whole sample, 4.2 s and 48.8% for the asymptomatic group and 7.1 s and 68.4% for the symptomatic group. When using the subjective method (EasyTear®), the respective repeatability and ICC values were 7.3 s and 32.7% for the whole sample, 6.5 s and 30.4% for the asymptomatic group and 8.6 s and 35.9% for the symptomatic group. The CA‐800 device provided significantly (p &lt; 0.001) shorter NIBUT values compared with EasyTear® for the whole sample (3.3 [2.9] vs. 8.1 [3.4] s), the asymptomatic (3.3 [3.0] vs. 7.7 [3.6] s) and the symptomatic (3.8 [2.9] vs. 8.6 [3.0] s) groups.ConclusionObjective (CA‐800) NIBUT assessment provides more reliable measurements than the conventional subjective technique using the EasyTear® device. However, CL practitioners should also be aware that the objective method indicates shorter NIBUT values. Symptomatic CL wearers may also need a higher number of NIBUT measurements to obtain reliable estimations.

Keratoconus Management in the Community: A Survey of Optometrists.

Defining the patterns of practice and referral criteria of optometrists within New Zealand to investigate the diagnosis and management of keratoconus. Optometrists recruited through the New Zealand Association of Optometrists, Cornea and Contact Lens Society of New Zealand, and private practices were invited to complete an anonymous survey. Responses were received from 168 optometrists (representing 20.0% of the optometrist population). Half (48%) of optometrists had ≥15 years of experience, and 22% prescribed soft contact lenses daily, whereas only 6.4% prescribed rigid gas-permeable (RGP) lenses daily. The main barriers to prescribing RGPs were experience with fitting, low market demand, and patient discomfort. When referring to an ophthalmologist, 41% reported referring on progression of corneal parameters, 27% on initial diagnosis, 21% at no set time, and 10% with a reduction in visual acuity. Most optometrists (64%) would refer for possible surgery when visual acuity dropped between 6/9 and 6/12. Optometrists with greater experience were more likely to prescribe RGP lenses and co-manage patients with ophthalmologists. Ownership of a corneal imaging unit suggested an increased likelihood of prescribing RGP lenses but did not alter referral patterns. This survey provides an overview of current practice and highlights the importance of optometrists in the diagnosis and management of keratoconus. There was a significant discrepancy in keratoconus management, regarding optical correction modality and referral criteria for ophthalmology review. Further interdisciplinary work is required between optometry and ophthalmology to standardize referral guidelines and enhance visual outcomes.

The corneal biomechanical differences after wearing orthokeratology lenses and multifocal soft lenses in children: A self-control study

BackgroundTo compare the changes in corneal biomechanics after orthokeratology (OK) lens and Defocus Incorporated Soft Contact (DISC) lens treatment. MethodsOf 28 myopic children were recruited, with one eye wearing OK lens and the other eye wearing DISC lens for one year, and the data after discontinued for 4 weeks were also collected. Major outcomes were corneal biomechanics and axial length (AL) elongation. ResultsThroughout the follow-up period, the DISC group had longer the first applanation (A1) time, larger A1 deformation amplitude, A1 deflection length (A1 DLL), and A1 deflection amplitude than the OK group. AL elongation was less in the OK group at each visit (all P < 0.05) but faster in the OK group than in the DISC group after discontinuation (P = 0.006). Moreover, AL elongation was related to baseline A1 time, A1 velocity and whole eye movement max in the DISC group, and in the OK group, was related to the baseline the second applanation (A2) DLL, A2 delta arc length and stiffness parameter A1 (all P < 0.05). ConclusionsThe cornea was more deformable after wearing DISC lens than OK lens, and corneal biomechanical parameters were associated with AL elongation. Eyes showed less AL elongation during OK lens treatment while faster AL elongation after discontinuation than DISC lens. The baseline corneal biomechanics may help to predict AL elongation in myopic control strategies.

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.

What is the willingness to pay for soft toric contact lenses?

Ashton Morgan, John Whitehead and Philip Morgan report on a recently published peer review paper in Contact Lens and Anterior Eye by the same authors that presents an economic analysis of the benefits of soft toric contact lenses 1

Cost-Effectiveness Analysis of Myopia Progression Interventions in Children

Several interventions exist for treating myopia progression in children. While these interventions' efficacy has been studied, their cost-effectiveness remains unknown and has not been compared. To determine cost-effective options for controlling myopia progression in children. In this cost-effectiveness analysis, a Markov model was designed to compare the cost-effectiveness of interventions for controlling myopia progression over 5 years from a societal perspective in a simulated hypothetical cohort of patients aged 10 years with myopia. Myopia interventions considered included atropine eye drops, 0.05% and 0.01%, defocus incorporated multiple segment spectacles, outdoor activity, soft contact lenses (daily disposable and multifocal), rigid gas-permeable contact lenses, progressive addition lenses, bifocal spectacle lenses, orthokeratology, highly aspherical lenslets (HALs), and red light therapy; all interventions were compared with single-vision lenses. Deterministic and probabilistic sensitivity analysis determined the association of model uncertainties with the cost-effectiveness. Costs were obtained from the charges of the Hospital Authority of Hong Kong and The Chinese University of Hong Kong Eye Center. The mean costs (in US dollars) per child included the cost of hospital visits, medications, and optical lenses. The outcomes of effectiveness were the annual spherical equivalent refraction (SER) and axial length (AL) reductions. Incremental cost-effectiveness ratios (ICERs) were calculated for each strategy relative to single-vision lenses over a time horizon of 5 years. Outdoor activity, atropine (0.05%), red light therapy, HALs, and orthokeratology were cost-effective. The ICER of atropine, 0.05%, was US $220/SER reduction; red light therapy, US $846/SER reduction; and HALs, US $448/SER reduction. Outdoor activity yielded a savings of US $5/SER reduction and US $8/AL reduction. Orthokeratology resulted in an ICER of US $2376/AL reduction. These findings suggest that atropine eye drops, 0.05%, and outdoor activity are cost-effective for controlling myopia progression in children. Though more expensive, red light therapy, HALs, and orthokeratology may also be cost-effective. The use of these interventions may help to control myopia in a cost-effective way.

Current approaches to soft contact lens handling training – Global perspectives

PurposeAll neophyte contact lens wearers require training on how to handle contact lenses. Currently, almost no published information exists describing the most common approaches used by those involved in such training in soft contact lens wearers. This study aimed to gather information on the approaches taken by those conducting this training worldwide. MethodsAn online survey was created in English and translated to Spanish and distributed internationally via social media, conference attendees, and professional contacts. The anonymous survey included information on workplace setting of respondents, information about the typical approaches used for application and removal of soft contact lenses, length of the appointment, and success rate with their approach. Survey responses were received between May 2021 and April 2022. ResultsA total of 511 individuals completed the survey and responses were received from 31 countries with 48.7% from the UK. The most common approach taught for application was to have the patient hold the upper eyelashes (84.7%) and to hold the lower eyelid with the same hand as the lens (89.4%). Lenses were applied directly to the cornea by 57.7% of the respondents. The most common approach taught for lens removal was to drag the lens inferiorly from the cornea prior to removal (49.3%). Most respondents did not use videos to aid the teaching appointment (62.0%); however, they felt that their approach was successful in most cases (90). Application and removal training sessions lasted a median of 30 min and contact lenses were typically dispensed after the instructor witnessing successful application and removal three times. ConclusionVarious methods are adopted globally for training of application and removal of soft contact lenses, with many advising a patient-specific approach is required for success. The results of this survey provide novel insights into soft contact lens handling training in clinical practice.

TEMPORARY KERATOPROSTHESIS COMBINED WITH VITRECTOMY FOR SEVERE GLOBE INJURY.

To describe a case of a 44-year-old man with ocular trauma after a mine explosion. From the moment of the injury, the patient reported significant visual impairment (no perception of light in the right eye and a perception of light without localization in the left eye). The patient was diagnosed with a double-sided penetrating corneal scleral wound and traumatic cataract, retinal detachment, and intraocular foreign bodies after a battlefield mine explosion. The three-stage procedure, consisting of using soft contact lens as temporary keratoprosthesis, vitrectomy, and penetrating keratoplasty, was performed in the damaged eye. A soft contact lens allowed for excellent visualization of the posterior segment during vitrectomy. At the 1-month follow-up, the eye that was operated on could sense light. The corneal transplant remained translucent, and the retina was attached. The described method, when performed by an experienced surgeon, may aid in simultaneously treating coexisting corneal opacification and vitreoretinal disorders.

Peripheral Defocus, Pupil Size, and Axial Eye Growth in Children Wearing Soft Multifocal Contact Lenses in the BLINK Study.

The purpose of this study was to evaluate the relationship between peripheral defocus and pupil size on axial growth in children randomly assigned to wear either single vision contact lenses, +1.50 diopter (D), or +2.50D addition multifocal contact lenses (MFCLs). Children 7 to 11 years old with myopia (-0.75 to -5.00 D; spherical component) and ≤1.00D astigmatism were enrolled. Autorefraction (horizontal meridian; right eye) was measured annually wearing contact lenses centrally and ±20 degrees, ±30 degrees, and ±40 degrees from the line of sight at near and distance. Photopic and mesopic pupil size were measured. The effects of peripheral defocus, treatment group, and pupil size on the 3-year change in axial length were modeled using multiple variables that evaluated defocus across the retina. Although several peripheral defocus variables were associated with slower axial growth with MFCLs, they were either no longer significant or not meaningfully associated with eye growth after the treatment group was included in the model. The treatment group assignment better explained the slower eye growth with +2.50 MFCLs than peripheral defocus. Photopic and mesopic pupil size did not modify eye growth with the +2.50 MFCL (all P ≥ 0.37). The optical signal causing slower axial elongation with +2.50 MFCLs is better explained by the lens type worn than by peripheral defocus. The signal might be something other than peripheral defocus, or there is not a linear dose-response relationship within treatment groups. We found no evidence to support pupil size as a criterion when deciding which myopic children to treat with MFCLs.

Case report: Application of prosthetic soft contact lens as bandage contact lens for band keratopathy

Soft prosthetic contact lenses (PCL) offer the broadest cosmetic options to enhance the appearance of sighted, non-sighted diseased or disfigured eyes. A forty-six-year-old female with a previous history of injury to the right eye with a pencil, presented to contact lens clinic with complaints of irritation, discomfort, and sensitivity to bright light. The patient was advised to use antibiotics and lubricants along with BCL to improve comfort. Initially, BCL was recommended as continuous wear to improve the comfort level. During the follow-up visit, the patient was concerned about cosmesis and symptom relief at the same time. The patient was fitted with type D prosthetic soft contact lens with continuous wear. This case report highlights the dual use of PCL. It enhances the cosmesis acts as a therapeutic agent or BCL.

Heavy metal deposition and parameter change of soft contact lenses by exposure to particulate matter

BackgroundParticulate matter (PM) is known to contain heavy metals and be harmful to the tissues and organs of the human body including the eyes. As such, in this study, the deposition of heavy metals from PM on soft contact lenses was examined, and changes in the lens parameters were further investigated.MethodsSix types of soft contact lenses were exposed to captured PM10 for eight hours. The central thickness, water content, refractive power, and oxygen transmissibility of each contact lens were measured after analyzing the amounts of six heavy metals adsorbed on the contact lenses.ResultsLead, manganese, barium, arsenic, vanadium, and cadmium were detected in the captured PM, and only lead was adsorbed on all soft contact lenses except senofilcon C. The largest deposition was 23.21 ± 0.70 (10− 3)µg/lens of the lead on lotrafilcon B. The oxygen transmissibility of nelfilcon A exhibited statistically significant changes, however, it was within the ISO standard tolerance. Nevertheless, changes in the central thickness, water content, and refractive power of each soft contact lens were not statistically significant.ConclusionsThis study revealed that a considerable amount of lead in PM10 was adsorbed on soft contact lenses. Amongst lens parameters, only oxygen transmissibility changed significantly. Thus, wearing soft contact lenses under high PM10 concentration might affect the physiology of the eyes.

YouTube as a learning source for contact lens insertion and removal

ABSTRACT Clinical relevance Contact lens neophytes often learn about contact lens insertion and removal through YouTube videos of unknown quality. Background This study evaluates the quality of soft contact lens insertion and removal videos on YouTube. Methods A search for the keywords ‘Contact lens insertion’, ‘Contact lens removal’, ‘Put in contact lens’, and ‘Take off contact lens’ was performed on YouTube. The first 50 videos for each keyword were evaluated. The number of views, source of the publisher, days since upload, and video quality were scored based on the content in the videos. The maximum score of insertion and removal videos were 7 and 5 respectively. The videos were classified into three groups by publisher category: videos published by eye care professionals, companies and YouTubers. Results Only 45 contact lens insertion and 44 removal videos met the inclusion criteria and were analysed. Insertion and removal videos published by YouTubers had the highest view and view rate. However, their quality scores were significantly lower than videos published by eye care professionals and companies. Videos uploaded by companies had the highest scores (insertion: 5.00 ± 1.10; removal: 3.25 ± 0.75). The mean scores of insertion and removal videos published by YouTubers were 1.65 ± 0.93 and 1.00 ± 0.89, respectively, while the insertion and removal videos uploaded by eye care professionals scored 3.58 ± 2.07 and 2.75 ± 1.53, respectively. There was also a negative correlation between the quality scores and view rate (p = 0.008, r = -0.41). Conclusion Contact lens insertion and removal videos uploaded by YouTubers had the highest view rate but the lowest quality. Videos made by companies included most essential elements.