Masked comparison of two silicone hydrogel bandage contact lenses after photorefractive keratectomy

PurposeTo compare the efficiency and safety of two bandage contact lenses after photorefractive keratectomy (PRK).MethodsIn this double-blind study, 45 patients (90 eyes) received PRK in both eyes and wore bandage contact lenses (BCLs), PureVision (Bausch & Lomb, Rochester, NY, USA) in one eye and PureVision2 (Bausch & Lomb, Rochester, NY, USA) in the other eye, randomly assigned. The medication regimen after surgery was the same for both eyes. The epithelial defect's size, conjunctival hyperemia and lens centration were graded objectively using slit-lamp biomicroscopy on days 1, 3 and 5 after surgery. Also ocular symptoms of discomfort including tearing, photophobia, foreign body sensation and visual fluctuations were assessed subjectively at each visit.ResultsThe mean epithelial defect size on the first day after operation was similar in eyes fitted with PureVision (30.08 ± 5.30 mm²) and PureVision2 (30.25 ± 5.72 mm²) lenses. (p = 0.79) Contact lens deposits and bulbar hyperaemia on days 1 and 3 after PRK were similar between the two eyes, but were significantly greater on day 5 for PureVision2 lenses. (p = 0.02; p = 0.04 respectively) There was no difference in contact lens decentration, and discomfort symptoms including pain, tearing, foreign body sensation, photophobia and visual fluctuations between the eyes fitted with PureVision and PureVision2. (p > 0.05)ConclusionsPureVision and PureVision2 contact lenses are equivalent as bandage lenses in important aspects such as corneal re-epithelialization and subjective comfort., although PureVision2 led to a higher incidence of contact lens deposits and conjunctival hyperemia early post-PRK.     

Rebound tonometry measurements over extended-wear bandage contact lenses

BackgroundThe aim of this study was to assess the validity of rebound tonometry measurements obtained over eyes wearing extended-wear bandage contact lenses with the highest oxygen transmissibility (Dk/t) value of 175 @ -3.00 D.MethodsA total of 151 normal eyes were included in this prospective pretest-posttest study. A rebound tonometer (iCare PRO) was used to collect intraocular pressure readings from “naked” eyes (eyes without contact lenses) and the same eyes wearing extended-wear lotrafilcon A bandage contact lenses (Alcon Air Optix Night & Day Aqua Contact Lenses). The mean pre- and post-application values were pooled and compared using the paired t-test.ResultsThe application of extended-wear lotrafilcon A contact lenses over normal eyes did not cause a statistically significant change in the intraocular pressure measurements obtained using an iCare PRO tonometer (13.74 ± 2.15 mm Hg vs. 13.77 ± 2.26 mm Hg, p-value = 0.6506).ConclusionBased on this study conducted on normal eyes, the removal of extended-wear bandage contact lenses is not necessary when taking intraocular pressure measurements using the iCare PRO rebound tonometer.     

Objective evaluation of static and dynamic behavior of different toric silicone-hydrogel contact lenses

PurposeThe present study aimed to estimate how orientation position, recovery time, and contact lens decentration, associated with visual performance, may vary on several designs of the most recent toric silicone-hydrogel toric contact lenses in two-time different moments.MethodsTo evaluate the toric silicone-hydrogel toric contact lens position and stability, it was conducted with a prospective, observational, randomized, and single-center case series including 95 astigmatic eyes wearing four toric silicone-hydrogel toric contact lenses for two weeks. Orientation and decentration were analyzed with ImageJ software from video-frames extracted with a Python application. Recovery time was evaluated after 45 degrees of inferior-temporal misorientation.ResultsEvaluation of misorientation after 20 min of wear revealed the highest amount for Saphir RX, −20.41 ± 10.84 deg, and lowest for Air Optix Aqua for Astigmatism, −1.43 ± 7.48 deg. The highest horizontal misalignment was found for Air Optix Aqua for Astigmatism, −0.627 ± 0.330 mm, and lowest for Biofinity Toric, 0.004 ± 0.270 mm. Vertical misalignment presented the highest value for Acuvue Vita for Astigmatism, −0.652 ± 0.369 mm, and lowest for Air Optix Aqua for Astigmatism, −0.126 ± 0.231 mm. Recovery time showed the highest amount for Saphir RX, 80.70 ± 33.26 s, and lowest for Biofinity Toric 43.67 ± 23.70 s. Only Air Optix Aqua for Astigmatism presented significant differences after two-week of wear for misorientation (P = 0.02) and horizontal misalignment (P < 0.001). When pairwise comparisons are made between toric silicone-hydrogel toric contact lenses, significant differences (P < 0.001) are found.ConclusionsAlthough there was acceptable fitting, based upon decentration, orientation, and recovery with the study contact lenses, the stabilization and profile design used in the Air Optix Aqua for Astigmatism helped to minimize rotation and vertical misalignment. In addition, the peri-ballast and thickness profile of the Biofinity Toric improved rotational recovery and horizontal misalignment compared to the other contact lenses. Finally, lenses with a better fitting profile showed better visual performance.     

Usefulness of bandage contact lenses in the immediate postoperative period after uneventful myopic LASIK

Purpose

To determine the usefulness of a silicone-hydrogel bandage contact lens (BCL) in the immediate postoperative period after uneventful myopic laser in-situ keratomileusis (LASIK).

Histochemical analysis of bandage contact lens precipitates.

Contact lens deposits have been reported previously with extended wear of soft contact lenses, with proteins, lipids, mucous, and various salts such as chloride, potassium and calcium being deposited on the lens surface [1]. We report an unusual case of precipitates on the surface of a bandage contact lens (BCL) following intensive treatment with topical preservative free artificial tears. Evaluation included microscopic and histochemical analysis of the BCL. We have also reviewed the literature for previous reports of contact lens precipitates.     

The effect of lens wear on refractive index of conventional hydrogel and silicone-hydrogel contact lenses: a comparative study.

PURPOSE: The purpose of this work was to evaluate the ability of four silicone-hydrogel contact lenses (galyfilcon A, balafilcon A, lotrafilcon A and lotrafilcon B) to retain their equilibrium water content before and after wear, through measurements of refractive index and compare with that of a conventional disposable hydrogel contact lens (etafilcon A). METHODS: The refractive indices of 115 contact lenses were measured using an automated refractometer (CLR 12-70, Index Instruments, Cambridge, U.K.) before and after a schedule of daily wear by 58 patients for 30 days in the case of silicone-hydrogel lenses and 15 days for the conventional contact lenses. RESULTS: In the silicone-hydrogel contact lenses the changes on the refractive indices were not statistically significant, however after being worn the refractive index of the conventional etalfilcon A hydrogel contact lens increased significantly (p<0.001). CONCLUSION: The results presented here show that after being worn the silicone-hydrogel contact lens, show more capacity to retain or to reach their initial equilibrium water content than conventional hydrogel contact lenses. This suggests that the silicone-hydrogel contact lenses are less susceptible to spoilation over time maintaining its biocompatibility and contributing to the clinical success of lens performance.     

Effects of senofilcon A and lotrafilcon B bandage contact lenses on epithelial healing and pain management after bilateral photorefractive keratectomy

PurposeThe purpose of this study was to compare postoperative epithelial healing time and ocular discomfort score in patients wearing two types of silicon hydrogel bandage contact lenses (BCLs) following bilateral photorefractive keratectomy (PRK).MethodsFor the study’s contralateral eye comparison, 43 patients who underwent bilateral PRK were randomized to be fitted for a senofilcon a lens in one eye and a lotrafilcon B lens in the other. The patients were masked to the specific BCL in each eye. On the first 3 days after PRK, the epithelial defect size was calculated, and patients reported their level of ocular discomfort, including pain, epiphora, and photophobia, on a visual analog scale (0 = no pain or discomfort, 10 = highest level of pain and discomfort).ResultsEpithelial defect size (mm²) did not differ significantly between the BCLs on Day 1 (senofilcon A vs. lotrafilcon B: 14.15 ± 5.59 vs. 14.93 ± 5.72, p = .327), Day 2 (senofilcon A vs. lotrafilcon B: 7.43 ± 4.67 vs. 7.04 ± 3.82, p = .586), or Day 3 (senofilcon A vs. lotrafilcon B: 0.59 ± 1.44 vs. 0.38 ± 1.08, p = .348) postoperation. By Day 3, re-epithelialization was complete in 35 eyes (81.3%) with senofilcon A lenses and 36 eyes (83.7%) with lotrafilcon B lenses. Patients reported less pain in eyes with senofilcon A lenses during the first 3 days postoperation (for all, p < .001) and less epiphora during the first 2 days postoperation (Day 1: p = .008, Day 2: p < .001, Day 3: p = .267) than in eyes with lotrafilcon B lenses. No significant difference in photophobia emerged between the BCLs postoperatively (for all, p > .05).ConclusionsAlthough duration of corneal re-epithelialization after PRK between the two BCLs did not differ significantly, senofilcon A lenses caused significantly less pain and epiphora after PRK.     

Randomized crossover trial of silicone hydrogel contact lenses

PurposeThe aim of the current study is to assess, using new technologies, the interaction of four monthly silicone hydrogel contact lenses on the ocular surface and the comfort over 15 days of use.MethodsProspective cross-over, randomized and double-masked study including four materials (lotrafilcon-B, samfilcon-A , comfilcon-A and filcom-V3). Clinical examination was performed in the following order: tear meniscus height, first break-up of the tear film, the average time of all tear film breakup incidents, bulbar redness, limbal redness (Keratograph 5M ,Oculus, Germany); central corneal thickness (Pentacam, Oculus, Germany), thermography values (FLIR A325; FLIR Systems Inc., USA), and slit-lamp evaluations, including ocular surface staining. Finally, subjective comfort was obtained from Contact Lens Dry Eye Questionnaire-8.ResultsThe impact of contact lens wear on the ocular surface didn’t show statistically significant changes over time except for corneal and conjunctival staining grades on day 15 compared to day 1 for the comfilcon A group (P = .003 and P = .01, respectively). Contact lens stability and impact on the ocular surface during contact lens wear didn’t show statistically significant changes over time except in the case of the comfilcon A material with respect to the irritation item (P = .01).ConclusionsThese results suggest that the impact of monthly silicone hydrogel contact lens materials on the ocular surface after and during contact lens wear, contact lens stability over time, and subjective comfort did not reveal any significant changes over 15 days of use for any of the materials.     

Trends in the use of silicone hydrogel contact lenses for daily wear

Although the first silicone hydrogel contact lenses introduced onto the world contact lens market in 1999 held approval for both daily wear and extended wear use, the latter modality was promoted much more heavily by the manufacturers. The first silicone hydrogel lenses specifically promoted for daily wear were introduced in 2003. Data that we have gathered from annual contact lens fitting surveys demonstrate an immediate increase in market share whereby this lens type now represents more than one-third of soft lens fits in the United Kingdom. The success of this lens category is attributed to the health and safety benefits of silicone hydrogel materials and the positive impact of lens manufacturers by way of the effective marketing and distribution of these products.     

Multi-site clinical assessment of Complete Revitalens MPDS in 2981 contact lens wearers across Europe and USA

PurposeTo evaluate ocular response and subject acceptance of a new multipurpose disinfecting solution (MPDS), Complete Revitalens (RevitaLens OcuTec in the US Market), for soft contact lens care in a large “real practice” setting.MethodThis is an international multi-center, open-label assessment carried out in 10 countries across Europe and in the USA. Up to 10 subjects who were currently wearing soft contact lenses for at least 1 year and using a MPS as a lens care system were included at each investigational site.ResultsData were collected from 996 European and 1985 American wearers, 75% of those patients wore silicone hydrogel contact lenses. Approximately 94% found the new MPDS “somewhat more effective” to “much more effective” in keeping contact lenses feeling clean and 88% found the new MPDS to be somewhat more effective to much more effective in keeping their lenses feeling comfortable in the evening. Over 93% reported an improvement in vision clearness in the evening after approximately 1 month while using the new MPDS. Wearers with grade 2, 3 or 4 of severity decreased by 11.3, 6.4 and 9.8% over 1 month period for redness, burning and irritation, respectively. After approximately 1 month 83% of wearers declared that they would prefer to use the new MPDS.ConclusionsOver 88% felt their lenses were somewhat to much more comfortable at the end-of-day and 94% found the new MPDS to be somewhat to much more effective in keeping their lenses feeling clean compared to their previous care system.     

Determining the spectral transmittance of photochromic contact lenses

PurposeThis study evaluates the spectral transmission of photochromic contact lenses.MethodA custom built photochromic filter transmission testing device (ICS photochromic bench) was developed to measure the spectral transmission of light adaptive filters. The spectral properties of seven contact lenses were measured using the ICS photochromic bench at 23⁰C and 35⁰C in their exposed (darkening) state at time points 0 s, 45 s, 90 s, and 15 min. and their unexposed (fading) state at 45 s, 15 min. and 20 min.. Mixed between and within repeated measures ANOVA (MRM-ANOVAs) and generalized additive modeling (GAMs) were used to compare the effects of temperature and solar exposure time on spectral transmittance of photochromic contact lenses.ResultsThe mean (±SD) transmission of photochromic contact lenses in the exposed state were 94.7 ± 0.2, 39.1 ± 1.4, 27.0 ± 0.7 and 14.7 ± 1.0, and 93.7 ± 0.9, 38.8 ± 2.4, 30.2 ± 1.8, and 26.1 ± 1.0 at times 0 s, 45 s, 90 s, and 15 min. at 23⁰C and 35⁰C respectively. The mean (±SD) transmission of photochromic contact lenses in the unexposed state were 18.3 ± 1.5, 71.3 ± 2.4, and 80.2 ± 2.4, and 39.1 ± 1.0, 90.6 ± 1.0 and 91.1 ± 0.9 at times 45 s, 15 min. and 20 min. at 23⁰C and 35⁰C respectively. There was a significant decrease in light transmission as solar exposure time increased (GAM, MRM-ANOVA, p < 0.05). There was a significant effect of temperature and solar exposure time on the photochromic contact lenses (GAM, MRM-ANOVA, p < 0.05). The differences in the light transmitted by the photochromic contact lenses occurred at time 90 s and 15 min (Tukey HSD, at 90 s and 15 min, p < 0.05), where contact lenses at a temperature of 35⁰C showed greater light transmission than that at 23⁰C. There were differences in spectral transmittance based on the temperature of the contact lens. Contact lenses at 35⁰C transmitted more light than at 23⁰C at all unexposed times (MRM-ANOVA, p < 0.05).ConclusionSpectral transmission of photochromic contact lenses were successfully measured with the ICS photochromic bench. Temperature appears to influence both the activation and deactivation of photochromic contact lenses such that the higher the temperature, the greater the light transmission.     

Clinical evaluation of different types of contact lenses in keratoconus management

PurposeTo compare the clinical and topographical findings of the keratoconus patients according to the prescribed contact lens type and to investigate the effects of corneal collagen cross-linking (CXL) and cone location on lens selection.MethodsThe records of 301 eyes of 195 keratoconus patients who were prescribed contact lenses were analyzed retrospectively. The eyes were grouped according to the lens type: Soft toric contact lens (STCL), rigid gas-permeable contact lens (RGPCL), hybrid contact lens (HCL) and mini-scleral contact lens (MSCL). The history of having CXL, ophthalmological examination findings, and the topographical findings were compared between the groups. Brown-Forsythe, Chi-square, and post-hoc tests were used to compare the groups. Mann-Whitney U test was used for subgroup analysis. Comparison of the lens-corrected visual acuity (LCVA) and spectacle-corrected visual acuity (SCVA) levels was made with Wilcoxon signed-ranks test.ResultsThere was no significant difference between the groups regarding topographical cone location, CXL history, spherical refraction, and LCVA. The difference between spectacle-corrected visual acuity and LCVA was higher in RGPCL and MSCL groups than STCL group (p=0.01). Keratometry of RGPCL and MSCL groups were higher than STCL and HCL groups (p=0.01, p<0.001). In RGPCL group, eyes with central cones had a higher increase in visual acuity with contact lenses compared to eyes with paracentral cones (p=0.043). STCL and MSCL were mostly prescribed in mild and severe keratoconic eyes, respectively. In RGPCL group, the increase in visual acuity with contact lens was higher in eyes treated with CXL (p= <0.01).ConclusionsWhile STCL and HCL were mostly prescribed in mild keratoconus, RGPCL and MSCL were selected for moderate or advanced disease. If appropriately chosen, all types of contact lenses could result in a good visual acuity level. CXL history did not affect the prescribed lens type. Having central cone location and CXL history in RGPCL group improved visual acuity more efficiently.     

Stabilization of comfort and visual quality after the insertion of soft contact lenses

PurposeTo evaluate comfort, visual function, and in vivo wettability after the insertion of hydrogel and silicone hydrogel contact lenses for a better understanding of how long practitioners should wait for the initial evaluation of soft contact lenses.MethodsA short-term prospective, contralateral, randomized, and participant-masked study was carried out. Twenty healthy participants (25.4 ± 2.6 years) were evaluated after the insertion of two different soft contact lenses at different times (1, 5, 10, 20, 30 min). Ocufilcon D (hydrogel) and Somofilcon A (silicone hydrogel) contact lenses were randomly assigned to both eyes of the same participant. Comfort, visual function under photopic conditions in terms of high-contrast visual acuity, low-contrast visual acuity, contrast sensitivity, and in vivo wettability were measured.ResultsThere was an increase in comfort (p < 0.001), high-contrast visual acuity (p < 0.05), and contrast sensitivity (p < 0.001, only with silicone hydrogel) directly related to time after contact lens insertion. Besides, in vivo wettability suffered a statistically significant deterioration directly related to time with both contact lenses (p < 0.05). Except for comfort and contrast sensitivity, all the parameters stabilized their values 10 min after the insertion of both soft contact lenses. Additionally, in vivo wettability and visual acuity differences were found between hydrogel and silicone hydrogel contact lenses (p < 0.05).ConclusionsIt would be possible to properly evaluate high-contrast visual acuity, low-contrast visual acuity, and in vivo wettability 10 min after the insertion of both soft contact lenses.     

Bitoric rigid gas permeable contact lenses in the optical management of penetrating keratoplasty

PurposeThe purpose of this study was to evaluate the complexity and effectiveness of fitting bitoric rigid gas permeable contact lenses (RGPCLs), compared to spherical RGPCLS, when used in the correction of high amounts of post-penetrating keratoplasty astigmatism.MethodsRecords of post-penetrating keratoplasty (PKP) patients being managed with bitoric RGPCLs were compared to controls (post-PKP patients managed with spherical RGPCLs). Factors that were analyzed included the number of diagnostic RGPCLs used to assess the initial fit, the number of RGPCLs ordered to finalize the fit and the number of total doctor visits to finalize the fit.ResultsFourteen eyes of 14 patients satisfied the study criteria. The average amount of total astigmatism in this study group was 10.0 D ± 5.0 compared to the control group which was 3.3 D ± 2.6. The number of diagnostic RGPCLs used for the study group was 1.2 ± 0.4 compared to 1.0 ± 0.0 for the control group. The mean number of contact lenses ordered to complete the fitting for the study group was 1.9 ± 0.7 compared to the control which was 2.1 ± 0.8. The study group presented for an average of 6.3 ± 1.6 visits whereas the control group presented for 4.9 ± 1.1 visits. Contact lens corrected acuity for the study group was 0.101 ± 0.11 (20/25) compared to the control group 0.08 ± 0.12 (20/24).ConclusionsThe complexity of fitting bitoric RGPCLs was found to be similar to fitting spherical RGPCLs on post-PKP eyes and the visual outcomes were not different.     

Vision stolen by a hidden thief: 5-Year retention of a bandage contact lens

An 80 year-old male patient was prescribed a bandage contact lens on the left eye 5 years ago because of an injury on the eye by a wooden stick. He was never followed up to remove the contact lens. Two years ago, he suffered from gradually decreased visual acuity in the left eye. After removing the contact lens, his visual acuity gradually increased to 12/20 and the symptom revealed. Intraocular pressure, corneal endothelium density, corneal curvature, and the anterior chamber depth were within the normal range in the left eye, and were comparable with the right eye. Although no permanent damage was found in the patient, a strict follow-up procedure is strongly recommended for patients who receive a bandage contact lens.     

Acanthamoeba keratitis in patients wearing scleral contact lenses

Purpose

To report a series of cases of Acanthamoeba keratitis (AK) in scleral lens wearers with keratoconus to determine whether this type of contact lens presents a greater risk for development of infection. Methods: This study reports three patients who wore scleral contact lenses to correct keratoconus and developed AK. The diagnoses of AK were established based on cultures of the cornea, scleral contact lenses, and contact lens paraphernalia. This study investigated the risk factors for infections. Results: The possible risks for AK in scleral contact lens wearers are hypoxic changes in the corneal epithelium because of the large diameter and minimal tear exchange, use of large amounts of saline solution necessary for scleral lens fitting, storing the scleral lens overnight in saline solution rather than contact lens multipurpose solutions, not rubbing the contact lens during cleaning, and the space between the cornea and the back surface of the scleral lens that might serve as a fluid reservoir and environment for Acanthamoeba multiplication. Two patients responded well to medical treatment of AK; one is still being treated. Conclusions: The recommendations for use and care of scleral contact lenses should be emphasized, especially regarding use of sterile saline (preferably single use), attention to rubbing the lens during cleaning, cleaning of the plunger, and overnight storage in fresh contact lens multipurpose solutions without topping off the lens solution in the case.     

Impact of soft contact lenses on lid- parallel conjunctival folds

PurposeLid-parallel conjunctival folds (LIPCOF) are related to dry eye symptoms and appear to be related to mechanical forces in blinks. The primary aim of this longitudinal, parallel group study was to investigate impact of contact lens wear (CLW) on LIPCOF and secondly the impact of contact lens wear on lid-wiper epitheliopathy (LWE) and dry eye symptoms.MethodsAfter a 2-week wash-out phase with a hydrogen peroxide care regimen, 30 experienced contact lens wearers (female: 25, male: 5; median age: 34.5 years) with at least LIPCOF Sum grade 1 (nasal + temporal LIPCOF, either eye) were randomised into three groups: one which discontinued CLW (SPEC), one which were refitted with senofilcon A two-weekly replacement daily wear silicone hydrogel (OAS) and one which continued to wear their habitual lenses (HCL). LIPCOF Sum and LWE were evaluated at the enrolment visit and over a period of 12 weeks. LIPCOF were classified by fold number using a four-grade scale. LWE was classified using a five-point scale after staining with lissamine green and fluorescein. Symptoms were evaluated with the Ocular Surface Disease Index (OSDI).ResultsOn enrolment, there were no differences between groups for LIPCOF Sum (median 2.0), LWE (1.0) and OSDI scores (12.5) (Kruskal-Wallis, p > 0.718). Median changes at 12-weeks follow-up compared to the enrolment visit were (HCL-group: 0.5, 0.0, 0.0; OAS-group: −1.0, −0.5, −10.42; SPEC-group: −0.5, −0.5, −5.21; LIPCOF, LWE and OSDI, respectively). LIPCOF (Friedman-Test, p = 0.178), LWE (p = 0.791) and OSDI (p = 0.874) were unaltered over the period of observation in the HCL group. LWE (p = 0.120) was unaltered in OAS group but LIPCOF (p = 0.001) and OSDI (p = 0.003) significantly improved. In the SPEC group LIPCOF (p = 0.031), LWE (p = 0.002) and OSDI (ANOVA repeated measurements, p = 0.034) changed significantly.ConclusionsRefitting experienced CLW with senofilcon A daily wear, 2-week reusable contact lenses, or ceasing lens wear, improved LIPCOF, LWE and dryness symptoms.     

The use of contact lenses among university students in Chengdu: Knowledge and practice of contact lens wearers

Purpose

To assess the prevalence and general knowledge of contact lens wearers among college students in Chengdu, a metroplolitan of Chinaand find out the routine habits of use and hygienic conditions when wearing contact lenses.