Factors in the success of new contact lens wearers

Purpose

To determine the first-year retention rate for patients fitted with contact lenses (CLs) and identify factors associated with retention and dropout.

Lipid deposition on contact lenses in symptomatic and asymptomatic contact lens wearers

PurposeLipid deposition on contact lenses (CL) has traditionally been believed to reduce comfort during CL wear. The purpose of this study was to quantify lipid deposition on CL in a group of symptomatic and asymptomatic adapted CL wearers.MethodsThis was a single-masked, randomized clinical trial. Only confirmed symptomatic (comfortable lens wear time (CWT) < 8 h and a noticeable reduction in comfort over the course of the day) and asymptomatic (CWT > 10 h and minimal reduction in comfort over the course of the day) participants were recruited to participate in the study. Participants wore senofilcon A lenses in combination with a polyquaternium-based care solution (OPTI-FREE Replenish). Worn CL samples were collected on Day 14. Deposited lipid amounts from the lenses (including cholesteryl ester, cholesterol and triolein) were quantified using a liquid chromatography-mass spectrometry technique.ResultsLipid deposition was significantly higher in CL extracts of asymptomatic wearers compared to the symptomatic wearers for all lipid types quantified, including cholesteryl ester (2.1 ± 0.6 vs 1.6 ± 0.5 log μg/lens), cholesterol (1.5 ± 0.3 vs 1.1 ± 0.3 log μg/lens) and triolein (0.3 ± 0.2 vs 0.1 ± 0.1 log μg/lens) (all p < 0.002). The amount of cholesteryl ester deposited was greatest (p = 0.0001), followed by cholesterol, then triolein, for both the asymptomatic and symptomatic groups (both p = 0.0001).ConclusionThis study demonstrated that the asymptomatic group deposited a significantly greater amount of lipid on their CL. Although lipid levels measured are considered low to trigger any observable clinical deposition, they may influence other clinical outcomes, particularly comfort.     

Efficacy of two silicone-hydrogel contact lenses for bandage use after photorefractive keratectomy

PurposeTo evaluate the efficacy of two silicone hydrogel (SiH) contact lenses, approved for continuous wear for one week, following photorefractive keratectomy (PRK).MethodsForty seven myopic patients (94 eyes) undergone bilateral PRK were enrolled in this prospective, double-masked, comparative study. One eye of each patient was fitted with a Lotrafilcon B lens (Ciba Vision, Duluth, US; 30-day recommended replacement) whereas the fellow eye was fitted with an Asmofilcon A lens (Menicon, Nagoya, Japan; 14-day recommended replacement). Epithelial defect size was assessed using slit lamp biomicroscopy on the day of surgery and at days 1–4 post-operatively. Uncorrected and best-corrected visual acuity and retinal straylight (C-Quant, Oculus Optigerate, Germany) were evaluated pre-operatively and one month post-operatively.ResultsAverage epithelial defect size for Asmofilcon A and Lotrafilcon B was 25.5 ± 11.0 mm² vs. 27.1 ± 9.9 mm² at day 1 (p = 0.007) and 6.3 ± 7.0 mm² vs. 9.2 ± 9.5 mm² at day 2 (p = 0.012) post-operatively. Re-epithelialization at day 3 was completed in 87.2% of the eyes fitted with Asmofilcon A lenses, compared to 74.5% with Lotrafilcon B lenses (p = 0.012). At the 3rd post-operative day 29.8% of re-epithelialized eyes showed irregular suture with Lotrafilcon B, compared to 12.8% eyes with Asmofilcon A lenses (p < 0.001). Finally, no statistically significant differences were found post-operatively between the two lenses retinal straylight (p = 0.98) and best-corrected visual acuity (p = 0.68).ConclusionsSiH lenses can be used as an effective bandage after PRK due to the limited time requested for achieving complete corneal re-epithelialization. Faster and smoother epithelial healing is provided with Asmofilcon A over Lotrafilcon B lenses.     

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.     

The use of daily disposable lenses in problematic reusable contact lens wearers

PurposeReplacing soft contact lenses (CLs) on a daily basis brings a number of advantages, most notably, reduced exposure to deposits, disinfectants, allergens, and other contaminants. This retrospective study estimated the prevalence of problems in current wearers of reusable soft CLs and tested the effect of refitting “problem” patients with daily disposable (DD) hydrogel lenses.MethodsPrevalence was estimated from 398 current reusable CL wearers for: frequent/constant discomfort or dryness, ≥2 h of uncomfortable wear, ≥grade 2 conjunctival hyperaemia (0–4), or ≥grade 3 corneal staining (0–15). In the second part of the study, 217 reusable CL wearers classified as problem patients were randomly refitted with DD lenses manufactured from one of two materials: etafilcon A (n = 96) or nelfilcon A (n = 121) and reassessed 1 week later.ResultsThirty-nine percent (154/398) had some qualifying criterion: reduced comfortable wearing time (CWT), 20%; dryness, 20%; irritation, 5%; corneal staining, 8%; and hyperaemia, 7%. After refitting with DDs, the prevalence of reduced CWT was decreased from 65% to 51% (P = 0.0039), dryness from 60% to 41% (P < 0.0001) and corneal staining from 28% to 21% (P = 0.04). There was no significant change in the prevalence of irritation, or hyperaemia. Some differences were noted between the two lens materials.ConclusionsA high proportion of reusable soft lens wearers encounter clinically relevant signs or symptoms with their current CLs. This study provides evidence that refitting with DD lenses is a useful strategy for alleviating some of the common problems of CL wear.     

Fast versus gradual adaptation of soft monthly contact lenses in neophyte wearers

AimTo determine if a gradual adaptation period is necessary for neophytes when fitted with modern hydrogel or silicone hydrogel reusable disposable contact lenses.MethodAcross four sites, 74 neophytes (18–28 years) were randomly assigned to a reusable lens cleaned nightly with Opti-Free® Puremoist® multi-purpose contact lens solution: Proclear® (hydrogel) or Biofinity® (silicone hydrogel) and an adaptation schedule: fast (10 h wear from the first day) or gradual (4 h on the first day, increasing their wear time by 2 h on each subsequent day until they had reached 10 h). Masked investigators graded ocular surface physiology and non-invasive tear breakup time (NIBUT) and a range of comfort, vision and lens handling subjective ratings (0–100 visual analogue scales) were recorded at the baseline visit and after 10 h of lens wear, 4–6 days and 12–14 days after lens fitting. Subjective scores were also repeated after 7 days.ResultsThere was no difference (p > 0.05) in ocular surface physiology or NIBUT between fast and gradual adaptation groups at any time point in either lens type with the exception of increased corneal staining (p = 0.019) in the silicone hydrogel fast adaptation group after 4–6 days, but was similar by 12–14 days. Subjective scores were also similar across the visits and lens types with the exception of ‘lens awareness’ (p = 0.019) which was less in the gradual versus the fast adaptation silicone hydrogel lens group at 12–14 days.ConclusionThere seems to be no clinical benefit for recommending a gradual adaptation period in new wearers fitted with modern soft reusable disposable contact lenses. The findings of this work add to a growing body of evidence suggesting that such advice is unnecessary in regular soft contact lens wear, which has important ramifications for the initial clinical management of these patients.     

Performance evaluation of delefilcon a water gradient daily disposable contact lenses in first-time contact lens wearers

Purpose

To evaluate the tolerability of and subject and investigator satisfaction with delefilcon A (DAILIES TOTAL1^®) daily disposable contact lenses in first-time contact lens wearers.

Hydrogen-peroxide and silicone-hydrogel contact lenses: Worsening of external eye condition and tear film instability

Purpose

The aim is discussing the origins of worsening of external eye condition (EEC) and of tear film (TF) instability after wear of silicone-hydrogel contact lenses (CLs) with hydrogen-peroxide (H₂O₂) care system.

Fast versus gradual adaptation of soft daily disposable contact lenses in neophyte wearers

PurposeDespite the widespread practice of gradually adapting all new soft contact lens wearers (neophytes), there is little evidence-based research underpinning such practice. This work determined if a gradual adaptation period is necessary for neophytes when fitted with modern hydrogel or silicone-hydrogel daily disposable contact lenses.MethodAt four sites, neophytes (19–32 years) were randomly assigned to an adaptation schedule: fast (10 h wear from the first day) or gradual (4 h on the first day, increasing their wear-time by 2 h on each subsequent day until they had reached 10 h) with hydrogel (n = 24 fast; n = 21 gradual) or silicone-hydrogel (n = 10 fast; n = 10 gradual) contact lenses. Masked investigators graded ocular surface physiology and non-invasive tear breakup time (NIBUT). A range of subjective scores (using 0–100 visual analogue scales) were recorded at the initial visit and after 10 h of lens wear, 4–6 days and 12–14 days after initial fitting. Subjective scores were also repeated after 7 days.ResultsThere was no difference (p > 0.05) in ocular surface physiology between the fast and gradual adaptation groups at any time point in either lens type. NIBUT was similar at all time points for both adaptation groups in both lens types with the exception that the gradual adaptation silicone-hydrogel wearers had a slightly longer NIBUT (p = 0.007) than the fast adaptation group at 12-14 days. Subjective scores were also similar across the visits and lens types with the exception of ‘lens awareness’ and ‘ease of lens removal’ which were better (p < 0.05) in the fast compared with the gradual adaptation hydrogel lens group at day 7. Additionally, ‘end-of-day discomfort’ was better (p = 0.02) in the fast compared with the gradual adaptation hydrogel lens group at 12–14 days.ConclusionThere appears to be no benefit in daily disposable soft contact lens adaptation for neophytes with modern contact lens materials.     

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.

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.     

A 12-month prospective clinical trial of comfilcon A silicone-hydrogel contact lenses worn on a 30-day continuous wear basis.

PURPOSE: To evaluate the clinical performance of comfilcon A (Biofinity) during 12 months of continuous wear compared to other silicone-hydrogel lenses. METHOD: Forty-five subjects were fitted in one eye with the comfilcon A (test) lens. For 22 subjects, the other eye was fitted with lotrafilcon A (group A) and for the remaining 23 subjects the other eye was fitted with balafilcon A (group B). Twelve-month data are presented on 48 measured variables. RESULTS: There were no serious adverse events during the course of the study. A total of 33 subjects completed the study, with only 4 discontinuations for lens-related reasons, spread proportionately between the lenses. On preference scales, the test lens was superior to both control lenses for comfort (p<0.05) and overall preference (p<0.05) and in group A for vision (p<0.05). On grading scales, the test lens scored better than both control lenses for overall comfort (p<0.1 for group A, p<0.05 for group B), comfort during the day (p<0.05), end-of-day comfort (p<0.05) and overall preference (p<0.05), and better in group A for general vision quality (p<0.01), night vision quality (p<0.01) and handling (p<0.05). All lenses performed to a comparable degree on the basis of microcysts and corneal staining. There were significant differences between lenses in producing limbal redness (p<0.05), bulbar conjunctival hyperemia (p<0.1) and conjunctival NaFl staining (p<0.01) with the control lens in group A showing the greatest effect and the control lens in group B the least. CONCLUSION: Comfilcon A offers performance advantages over first generation silicone-hydrogel materials for continuous wear.     

Bulbar conjunctival staining in contact lens wearers and non lens wearers and its association with symptomatology.

It has become increasingly apparent that bulbar conjunctival anomalies are associated with dry eye symptoms. Lissamine green (LG) and sodium fluorescein (FL) conjunctival staining were assessed in 102 soft contact lens wearers and 79 non contact lens wearers. Conjunctival staining was increased in symptomatic patients. Both LG and FL staining were discriminating factors for symptomatic non lens wearers (>or=grade 1.5, p<0.001). Only LG staining could discriminate symptomatic from asymptomatic lens wearers (>or=grade 1.0, p=0.007). This analysis confirms the involvement of the conjunctiva in dry eye symptomatology. While both stains are useful, LG shows greater specificity for symptomatic subjects, particularly in contact lens wearer. It is recommended that the examination of patients complaining of dry eyes, in particular contact lens wearing patients include as routine, the examination of the conjunctiva with lissamine green.     

Therapeutic contact lenses

The indications for therapeutic contact lenses and details some of the more commonly encountered conditions where they have proved to be of great benefit are reviewed. A brief overview is given of the lens material and designs currently available in thisfield and advice on the management of patients requiring this type of lens modality.     

Clinical evaluation of a new multi-purpose disinfecting solution in symptomatic contact lens wearers.

PURPOSE: To evaluate the safety and efficacy of a new multi-purpose disinfecting solution (MPDS) in symptomatic soft contact lens wearers using Group IV soft lenses and compare its performance with that of a marketed MPS. METHODS: This was a 4-week, randomized, concurrently controlled, double-masked, multi-site study involving 362 subjects at 19 investigational sites in the US. Existing Group IV lens wearers, pre-screened to be symptomatic for contact lens-related ocular discomfort, were fitted with a new pair of lenses that matched their pre-study lens brand then randomly assigned to one of two treatment regimens: Regimen 1 (OPTI-FREE RepleniSH MPDS, Alcon Laboratories Inc.) or Regimen 2 (ReNu MultiPlus MPS No Rub Formula, Bausch and Lomb Inc.). At Day 0 (baseline), Days 14 and 28 subjects recorded comfort and ocular symptoms, wearing time, rewetting drop and lens removal frequency, and investigators assessed slit-lamp findings, lens deposits and wettability, and visual acuity. RESULTS: Total corneal staining mean score was significantly lower for the Regimen 1 group at Day 14 (P相似文献   

Predicting initial base curve of the rigid contact lenses according to Javal keratometry findings in patients with keratoconus

PurposeTo find an appropriate correlation between the base curve (BC) of rigid gas permeable (RGP) contact lenses and manual keratometry findings in Iranian patients with keratoconus (KCN) in order to simplify the fitting process, reduce the time, and lower the costs.MethodThis retrospective study was done in 121 eyes of 69 patients with KCN fitted with a specific trial set of RGP contact lenses over a 7-year period. The specifications of the final lens parameters included power, total diameter (1), and BC, the first two of which were fixed in all of the lenses in the trial set while BC was changed in 0.1-mm steps. Javal keratometer was used to measure keratometric values. The final fit assessment was performed based on the standard criterion of "three-point touch".ResultSingle and multiple linear correlations were done and the result was the following equation: BC = 2.455 (constant of the final multiple regression model) + 0.280 (steep keratometry) + 0.368 (flat keratometry) + 0.047 (corneal astigmatism)ConclusionThe advantages of this study include simplifying the RGP fitting process, reducing the examination time, lowering the costs, enhancing the confidence of the examiners and patients, easier lens fitting in remote places where more advanced devices are not accessible.     

Applanation tonometry in silicone hydrogel contact lens wearers

INTRODUCTION: Previous studies have investigated intraocular pressure (IOP) measurements through conventional soft (hydrogel) therapeutic contact lenses, and have found that an accurate IOP can be recorded in normal eyes, and in eyes with abnormal anterior segments. The IOP measurement through soft contact lenses may be affected by the water content and centre thickness of the lens. Silicone hydrogel contact lenses are now being used as therapeutic contact lenses due to their high oxygen permeability. The purpose of this study is to investigate if IOP can be accurately measured in a subject wearing a silicone hydrogel contact lens. METHODS: In a cohort study, the IOP was measured with a Goldmann applanation tonometer without a contact lens and then repeated with a hydrogel contact lens in situ. RESULTS: The IOP of 20 eyes of 10 volunteers with no ocular pathology was measured. The mean difference (+/-S.D.) found between IOP measurement with (mean 15.55+/-1.70 mmHg) and without (mean 16.05+/-1.90 mmHg) contact lens was found to be -0.5+/-0.89 mmHg. Statistical analysis was performed which revealed a correlation coefficient of 0.89. No significant statistical difference was found between the two groups with paired t-test (p=0.19). CONCLUSION: Accurate measurement of IOP by applanation tonometry can be achieved through a silicone hydrogel contact lens.