Prescribing daily disposable contact lenses in the UK.

Patterns of prescribing daily disposable contact lenses in the UK were determined by mining through data gathered from annual contact lens fitting surveys conducted over the past 12 years. Spherical, toric and multifocal design daily disposable lenses represent a substantial proportion of all contact lenses prescribed, reflecting the significant ocular health and lifestyle advantages offered by this lens category.     

Acanthamoeba keratitis associated with misuse of daily disposable contact lenses.

PURPOSE: To report a case of Acanthamoeba keratitis that occurred in a daily disposable contact lens wearer. METHOD: Case report. RESULTS: A 70-year-old gentleman presented to eye casualty with a red left eye with reduced vision and corneal epithelial changes. Acanthamoeba keratitis was not suspected initially as he was a daily disposable contact lens wearer. This led to a delay of 17 days in initiating treatment. He responded well to topical polyhexamethylene biguanide and propamidine and made a full recovery. CONCLUSION: Acanthamoeba keratitis can occur in patients who reuse daily disposable contact lenses. A diagnosis of Acanthamoeba keratitis can be difficult to make and should be considered in all patients who wear contact lenses, including daily disposable lenses. All patients who wear daily disposable contact lenses should be reminded that the benefits of this modality of contact lens are only possible if the lenses are worn once and thrown away.     

In vitro power profiles of daily disposable contact lenses

PurposeTo evaluate and compare the distribution of refractive power within the optic zone of different soft contact lenses and to investigate the effect of lens decentration on the power profiles.MethodsThe Nimo TR1504 instrument was used to measure the optical power across different aperture diameters (from 1.5 mm to 5.5 mm in steps of 0.5 mm) of four daily disposable contact lenses: DAILIES TOTAL1, Proclear 1-Day, SofLens daily disposable and 1-DAY ACUVUE MOIST. Measurements were performed using a wet cell. Power data were evaluated when contact lenses were in its centered position and after inducing different amounts of lens decentration (from 0.2 mm to 1.0 mm in steps of 0.2 mm).ResultsAll contact lenses showed an increase – more negative – in lens power with distance from the lens center. The amount of change varied depending on the lens. It was about 10% of lens power for DAILIES TOTAL1 (−0.29 diopters (D)), SofLens daily disposable (−0.36 D), and Proclear 1-Day (−0.32 D) whereas 1-DAY ACUVUE MOIST showed a percentage variation of 3.3% (−0.10 D). After inducing a lens decentration up to 1 mm, the power curves were shifted in the negative direction. However, the change obtained in lens power compared with well-centered position was always lower than a quarter of diopter both for all the lenses and aperture diameters.ConclusionsOur results showed a variation of the refractive power from the lens center, becoming more negative toward the periphery, with a negligible effect of the decentration for all disposable contact lenses studied.     

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.

Effect of material ionicity on the performance of daily disposable contact lenses.

The surface of hydrophilic contact lenses is intrinsically hydrophobic. Biocompatibility requires the contact lens surface to be coated with a lipoproteinic biofilm produced by the ocular secretion. For daily disposable modality of wear it is essential that biocompatibility, clinically represented by good in vivo wettability and subjective acceptance, is achieved as quickly as possible following insertion, as the process needs to be repeated daily. It has been hypothesised that non-ionic materials will not achieve biocompatibility as rapidly as ionic materials owing to the latter's ability to attract high levels of adsorbed proteins. The current investigation was a double-masked crossover study that evaluated, over 1 week of wear, a new non-ionic material (Nelfilcon A) and a current ionic material (Etafilcon A) under daily disposable modality. The results obtained showed that overall, both contact lens materials achieved good in vivo tear stability over the first 30 min of wear and good subjective acceptance that remained stable over the period of wear. The results obtained demonstrate that a non-ionic material can achieve rapid biocompatibility and subjective acceptance in a similar manner to an ionic material.     

Clinical performance of daily disposable soft contact lenses using sustained release technology.

PURPOSE: Polyvinyl alcohol (PVA) is a successful tear film stabiliser and is widely used in comfort drops and some soft contact lens materials. A PVA-containing lens, nelfilcon A has been modified to include additional (non-functional) PVA in order to provide improved comfort. This study aims to examine the clinical performance of this nelfilcon A lens with AquaRelease (AquaRelease). METHODS: Two contralateral, investigator masked, open label, subjective and objective evaluations were conducted. The first examined the effect of adding increased molecular weight PVA to nelfilcon A (n=5), and the second compared this AquaRelease lens to ocufilcon B (n=34). The principal measures were non-invasive break-up time (NIBUT) and subjective comfort, which were assessed at the beginning and end of a week of daily wear, and three times throughout 1 day at 8, 12 and 16 h. RESULTS: All subjects successfully completed the daily wearing schedule of 16h. On initial insertion, subjective comfort and NIBUT improved for AquaRelease than original nelfilcon A lenses (p<0.05). Initial comfort was better for AquaRelease compared to ocufilcon B lenses (p=0.01); however, NIBUT was not statistically different (11.7+/-15.6s versus 8.4+/-6.8s; p=0.26). Subjective comfort decreased with time (p<0.001), but there was no significant difference between AquaRelease and ocufilcon B lenses (p=0.16). NIBUT was not significantly affected by time (p=0.56) or between lenses (p=0.33). At the end of a weeks' wear, subjective initial, end-of-day, overall comfort and vision were rated significantly better with AquaRelease than ocufilcon B (p<0.01). CONCLUSIONS: Release of additional non-functionalised PVA from the nelfilcon A lenses appears to enhance comfortable contact lens wear.     

Patient experience and physiological response to two commercially available daily disposable myopia control contact lenses

BackgroundA range of myopia management (MM) contact lenses are becoming available to practitioners. These lenses are designed to slow myopia progression and axial elongation. This study explored the initial experience of participants wearing daily disposable MM contact lenses to investigate established factors previously associated with successful lens wear.MethodsThis was a prospective, double-masked, crossover study. Twenty participants aged 18–30 years old were assigned to wear two daily disposable MM lenses in a randomised order. Visual acuity, contrast sensitivity, and amplitude/lag of accommodation were assessed at baseline, post-insertion, and after 2 and 6 h of lens wear. Self-reported lens comfort and vision quality were recorded at the same timepoints, and at 10 h post-insertion. Pairwise comparisons were performed between the two lenses at each timepoint, as well as assessing changes throughout wear. The relationship of the measured parameters to overall lens satisfaction was also assessed.ResultsThere were no significant differences between the two MM lenses at any timepoint for any of the participant-reported parameters, including overall satisfaction. A small difference in visual acuity was noted at 6 h post-insertion, although this is unlikely to be clinically significant. Comfort decreased throughout the day, most notably at 10 h post-insertion. A moderate positive correlation was observed between participant-reported visual quality and overall satisfaction. A similar pattern was seen for comfort and overall satisfaction. Self-reported vision quality and measured visual acuity were poorly correlated, highlighting the benefit of subjectively assessing the quality of vision with these lenses.ConclusionsThe participants demonstrated comparable measures across a range of measures between the two MM lenses. Notably, half of the participants demonstrated a clear lens preference, although the preferred lens varied between individuals. Candidates for MM may benefit from trialling more than one MM lens design, to maximise initial wearing satisfaction.     

Evaluation of daily disposable senofilcon A contact lenses in a symptomatic population

PurposeTo evaluate the comfort performance of ACUVUE OASYS® 1-Day with HydraLuxe? Technology among symptomatic contact lens wearers by using Contact Lens User Experience (CLUE) comfort scores and Contact Lens Dry Eye Questionnaire 8 (CLDEQ-8) discomfort and dryness scores.MethodsThree clinical trials evaluated comfort and dryness when refitting symptomatic contact lens wearers to ACUVUE OASYS® 1-Day with HydraLuxe? lenses. This analysis combined the CLUE comfort and CLDEQ-8 scores obtained at baseline and 2-week follow-up and compared average scores between visits. Subjects were grouped by habitual lens modality (daily disposable or daily wear reusable) and habitual lens material (silicone hydrogel or hydrogel). The analysis included data from 107 subjects.ResultsSignificant increases in mean CLUE comfort scores between baseline and 2–week follow-up occurred in all subject groups across habitual lens modality and material, indicating an improvement in overall comfort. CLUE comfort score improved clinically (≥5-point increase) among 75.7% of subjects (81/107). Similarly, significant decrease in mean CLDEQ-8 scores between baseline and 2-week follow-up occurred in all subject groups, indicating a decrease in the prevalence of dryness and discomfort symptoms. CLDEQ-8 score improved clinically (≥3-point reduction) among 82.2% of subjects (88/107). A majority of subjects (57.0%) became asymptomatic (CLDEQ-8 score ≤ 11 points) after 2 weeks of bilateral wear.ConclusionRefitting symptomatic contact lens patients to ACUVUE OASYS® 1-Day with HydraLuxe? can improve overall comfort and reduce symptoms of dryness and discomfort, irrespective of the previous lens modality or habitual lens material.     

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.     

Ultraviolet (UV) transmittance characteristics of daily disposable and silicone hydrogel contact lenses.

The ultraviolet (UV) transmittance spectra of daily wear hydrogel and disposable silicone hydrogel contact lenses were measured. Average transmittance percentages were calculated for each lens for the entire UV spectrum and individually for the UVC, UVB and UVA portions of the spectrum. The significance of the differences in transmittance spectra obtained for the lenses was analysed using a one-way ANOVA planned comparisons test (alpha=0.05). The transmittance data were then used to calculate a UV protection factor (PF) for each contact lens brand tested. The PFs for 1-DAY ACUVUE MOIST (6.22), ACUVUE ADVANCE (10.02) and ACUVUE OASYS (11.96) contact lenses show that these contact lenses have superior UV-blocking capabilities. The PFs for Focus DAILIES (1.79), SofLens 1-day disposables (1.72), NIGHT & DAY (1.84), O2 Optix (1.99) and Purevision (2.62) show that these contact lenses posses more modest UV-blocking characteristics. This paper reviews the importance of protection of the anterior ocular surface from UV damage and quantifies the protection afforded by selected commercially available disposable contact lenses.     

Local oxygen transmissibility of disposable contact lenses.

AIM: Despite global standardisation in measurement of oxygen transmissibility (Dk/t), in our clinic we continue to see limbal vasculature changes in patients wearing some disposable lenses. The use of central Dk/t as a simple designator of a contact lens oxygen performance has clearly failed, it being acknowledged as often unrelated to the oxygen performance of the lens periphery. This study investigates a new criterion for contact lens oxygen transmissibility, the local Dk/t. METHOD: The study measured 20 spherical disposable lens brands (power range: -15.00 to +8.00 D) and 8 toric lens brands (power range: -8.00 to +4.00 D sphere, with a -1.00 D/-1.25 D x 180). An electro-mechanical gauge (Heidenhain, Germany) was used to measure lens thickness (t) at different positions on the lens. Oxygen permeability (Dk) of each lens material was calculated from the equation Dk =1.67 e (0.0397 x water content) of Morgan and Efron [Contact Lens Anterior Eye 21 (1998) 3] who used ISO/ANSI standard methodologies. The local Dk/t value was calculated from the point of maximum thickness on the lens and compared to the criterion of 12 Fatt units set by Benjamin [Int. Contact Lens Clin. 23 (1996) 188], to provide corneal oxygenation greater than or comparable to that available in the normal closed eye. RESULTS: All lens types with a water content over 65% had a local Dk/t of 12 Fatt units or more for most or all lens powers: CIBAVision FocusDailies, Bausch & Lomb Soflens66, CooperVision Actifresh400, and CIBAVision PrecisionUV. In addition, some lenses in the 55-62% water content range had some lens powers with a local Dk/t in excess of 12: CooperVision Proclear, Johnson & Johnson Acuvue 1 and CIBAVision Focus 2 week. None of the disposable toric lenses had a minimum Dk/t of 12 or more. The silicone-hydrogels, Bausch & Lomb PureVision and CIBAVision Focus Night&Day, comfortably exceeded Dk/t of 50 for all lens powers. CONCLUSION: Some current disposable soft lenses have local Dk/t values below physiological requirements. Contact lens manufacturers and international standards organisations should consider introducing the labelling of local Dk/t values on lens packaging so that clinicians can make informed prescribing decisions.     

Comparative performance of disposable soft contact lenses.

A short-term clinical study was undertaken to compare and evaluate the fit and clinical behaviour of eight disposable hydrogel contact lenses. Thirty subjects were enrolled in a 1-day, randomised, double-masked study. The lenses compared were Vistakon Acuvue (8.80), Vistakon Surevue (8.80), Aspect Frequency-55, Bausch & Lomb Medalist (SeeQuence 2), Ciba Focus (8.90), Lunelle Rythmic, Pilkington Barnes Hind Precision-Wand Wesley Jessen Freshlook. Three of the eight designs, Acuvue (86.7%), Precision-UV (86.7%) and Frequency-55 (90%), achieved relatively high levels of fitting success. The Rythmic lenses achieved the lowest success rate (70%) showing significantly greater downward decentration than the other designs. Although all the lenses were designed to fit a wide variety of eyes, they exhibited widely varying fitting characteristics. Some were more successful than others. The study shows that it is necessary for practitioners to utilise a range of lens designs in order to fit satisfactorily the typical contact lens population.     

In-vitro dewetting properties of planned replacement and daily disposable silicone hydrogel contact lenses

AimTo compare the in-vitro videokeratoscopic surface dewetting properties of new-generation silicone hydrogel (SiH) planned replacement contact lenses (CL) with those of daily disposable CLs.MethodA chrome coated cornea model was used for the in-vitro evaluation of surface dewetting. Pre-lens and post-lens film layers were formed by instilling a normal preservative-free normal saline solution (PFNs) (0.9 %) before and after the placement of the CL on the model cornea. The tests were carried out on fanfilcon A, lotrafilcon B, samfilcon A, and senofilcon A lenses, as well as such daily disposable lenses as delefilcon, nesofilcon A and senofilcon one day. Using videokeratoscopic methods, images were obtained at 30-second intervals up to 180 s in the lens and control groups and were analyzed by the ImajeJ® program.ResultsThe mean measured area of the keratoscopic rings was largest in the fanfilcon group (67.56 mm²), followed by 61.53 mm² in the lotrafilcon A group and 64.60 mm² in the samfilcon group, while the smallest area was measured in the senofilcon A group, at 56.90 mm². The area was measured as 64.33, 63.09 and 68.39 mm² for the delefilcon, nesofilcon and Senofilcon one day CLs, respectively. The dewetting patterns and properties differed in the CL groups (p < 0.05), while no significant differences were found between the measured areas of the planned replacement and daily disposable CL groups (p > 0.05).DiscussionVideokeratoscopy using in-vitro cornea models has been identified as a reproducible and reliable method for the analysis of the surface dewetting of CLs. The dewetting characteristics of CL groups have been found to differ from each other, despite all being produced from SiH materials. The surface wetting coating has been shown to affect CL dewetting performance.     

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.     

Ultraviolet transmittance of the Vistakon disposable contact lenses.

With increasing scientific evidence demonstrating the harmful effects of ultraviolet (UV) radiation on different ocular tissues, contact lens manufacturers are incorporating UV blocking monomers into their contact lenses. This study evaluated the transmittance spectra of Vistakon's disposable soft contact lenses (1 Day Acuvue, Acuvue, Surevue, and Vistavue). All except Vistavue contain a UV blocking agent. Transmittance for each lens was recorded from 200 to 400 nm on a Shimadzu UV 160U Dual Beam Recording Spectrophotometer. The results indicate that lenses which incorporate the UV blocking monomer significantly reduced the transmission of W radiation while untreated lenses did not. Our findings indicate that 1 Day Acuvue, Surevue, and Acuvue meet the American National Standards Institution (ANSI) Standard Z80.20 for Class 2 UV blockers: a maximum of 30% transmittance of UVA wavelengths and 5% transmittance of UVB wavelengths. In contrast, the Vistavue lens demonstrated negligible UV blockage. Our technique, in which contact lenses were placed directly in front of a measuring beam, was accurate and simpler than previously reported methods and may be useful in future studies. We found that UV blocking soft contact lenses can be a viable alternative for spectacles in protecting internal ocular structures from UV radiation. However, the external structures of the eye remain at risk and would continue to benefit from the use of UV blocking sunglasses or spectacle lenses.     

Ocular health of children wearing daily disposable contact lenses over a 6-year period

PurposeTo report on the ocular health and safety of children fit with soft hydrogel daily-disposable contact lenses, and followed for 6-years in a double-masked clinical trial investigating the performance of a dual-focus contact lens designed to control myopia progression.MethodsChildren aged 8−12 years, naïve to contact lens wear, were enrolled across four international sites. During years 1–3, children were randomised to either MiSight® 1 day or Proclear® 1 day (both omafilcon A, CooperVision, Inc.). The lenses were identical in material and geometry except for the front optical zone design. At the end of year-3, all those wearing Proclear 1 day were switched to MiSight 1 day, therefore all wore MiSight 1 day in years 4−6. Subjects agreed to wear the lenses at least 10-hours/day, 6-days/week. After dispensing, study visits were at 1-week, 1-month, 6-months and every 6-months until 6-years. At each visit, ocular measurements and subjective responses were recorded. Biomicroscopy used 0–4 grading scales; grade 0 represented no findings.Results144 children were enrolled: 69F:75M; mean age 10.1 years; mean cycloplegic spherical-equivalent refraction -2.11D; ethnicities included 34 East-Asian, 12 West-Asian, and 79 Caucasian. 92 completed the 6-years. Only three subjects discontinued due to an ocular adverse event (AE). No contact lens related AEs were classified as serious. The incidence rate of infiltrative AEs was 0.61% (6.1/1000 wearing-years; 95%CI: 0.24%–1.57%). The most common biomicroscopy findings were limbal, bulbar and tarsal hyperaemia and tarsal roughness. 99% of all biomicroscopy findings were grade-1 or lower. After 6-years of lens wear, ocular health by biomicroscopy was similar to pre-lens wear.ConclusionsAcross the 6-years, there were no contact lens related serious AEs and biomicroscopy showed no significant changes. Results suggest that children this age can successfully wear daily-disposable hydrogel contact lenses with minimal impact on ocular physiology.     

Variation in sag values in daily disposable,reusable and toric soft contact lenses

PurposeWhile knowledge of the ocular surface sagittal height (OC-SAG) is increasing with newer instrumentation, understanding of soft lens sag values (CL-SAG) in daily clinical practice is limited. This study aimed to report the differences in CL-SAG of a large collection of daily disposable (DD), reusable (2-week and 4-week replacement) and toric lens designs.Methods12 different spherical DD and 15 reusable lens types were analysed (labelled power −3.00D); 17 different toric lens types analysed (6 DD and 11 reusable) in −3.00D =C 0.75 × 180. Posterior CL-SAG was measured directly using a spectral domain OCT-based instrument (Optimec is830).ResultsThe range in CL-SAG for DDs was 3,398-3,912 microns, for reusable lenses 3,372-4,004 microns and for toric lenses 3,536-4,157 microns. Lens diameter and BC together influence CL-SAG values. For lenses with the same labelled base curve (BC), the maximum difference in the DD group was 264 microns, in the reusable group 418 microns and in the toric group 345 microns. Three lens designs within the DD group and five in the reusable group offer two BCs, with an average variation (±SD) in CL-SAG of 276 ± 39 microns; one toric lens with two BCs showed a 377-micron difference.ConclusionsMarked differences in CL-SAG values were found in this study, also between lenses of the same BC. While ECPs should be aware that diameter and BC together influence CL-SAG, this also indicates that lens substitution based on BC alone could result in substantial differences in CL-SAG, with a potential impact on lens fit. Lens designs offering two BCs showed a somewhat narrow band in absolute terms in CL-SAG, and switching from a spherical to a toric lens of the same lens manufacturer could result in a significant change in CL-SAG.     

Clinical performances of two disposable soft contact lenses of different materials on Hong Kong-Chinese.

Dryness due to contact lens wear and poor wetting of contact lenses among contact lens wearers is a common observation and contact lens manufacturers have introduced new, better quality soft lens materials that are claimed to be more deposit resistant, and/or dehydration resistant. The purpose of this study was to evaluate and compare the clinical performance of Hydron ActiSoft 60 section sign, made of a new material (HyGMAtrade mark) which is claimed to be dehydration resistant with excellent wettability, with ActiFresh 400, made of conventional non-ionic hydrogel material. The experiment was conducted as a double-masked, randomised, cross-over study. Clinical assessment included pre-lens non-invasive tear break up time (PL-NITBUT), logMar visual acuity and contrast sensitivity (CS). Corneal staining, if any, was recorded at each visit. Subjective ratings in regard to dryness, grittiness, lens awareness, vision, comfort, handling (removal), handling (cleaning) and the overall preference of each lens type were obtained at the end of 3 (Phase A) and 6 months' (Phase B) wear. Twenty-eight subjects successfully completed the study. In Phase A, no significant differences were found in both baseline PL-NITBUT and PL-NITBUT after wearing the same lenses for 1 month between the two lens types. In phase B, baseline PL-NITBUT for ActiFresh 400 was significantly shorter than that for ActiSoft 60. However, after 1 month of wear, the difference in PL-NITBUT between the two lens types was no longer significant. PL-NITBUT was significantly reduced after 1 month's wear for both ActiSoft 60 and Actifresh 400, and in both Phase A and Phase B. The two lens types provided comparable logMAR visual acuity, and there was no significant differences in CS (Pelli Robson) between spectacle lens correction (equivalent spheres) and either lens type. The incidence of corneal epithelial staining was significantly higher and more severe with ActiFresh 400 than with ActiSoft 60, both in Phase A and Phase B. Statistically, there were no significant differences in the scores to the set of questions listed in the questionnaire between the two lens types, except for lens awareness and lens handling. Of the subjects having a preference for one lens, more subjects preferred ActiSoft 60 than ActiFresh 400. In terms of overall preference of the two lens types, at the end of Phase A, 50% of the subjects preferred ActiSoft 60 while only 30% preferred ActiFresh 400, the remaining 20% had no preference. However, by the end of Phase B, preferences for ActiSoft 60 and ActiFresh 400 were comparable. This appeared to be due mainly to the ease of lens handling of the latter.     

Ocular physiology and comfort in neophyte subjects fitted with daily disposable silicone hydrogel contact lenses

PurposeTo evaluate the performance of a silicone hydrogel daily disposable lens in neophyte subjects over 12 months.MethodsSeventy four subjects with no previous contact lens experience were randomised to wear narafilcon A (1 DAY ACUVUE^® TruEye™) lenses (LW group) or to wear no contact lenses (NLW group) for 12 months. Biomicroscopy (performed by a masked investigator), visual acuity and subjective response scores were recorded at an initial visit and six follow-up visits, in addition to lens fit and surface evaluation for the LW group. Comfort was recorded with SMS messaging.ResultsFifteen of the LW group discontinued before the end of the study, compared with six of the NLW group. Measured visual acuity was about half a line better for the NLW group as these subjects were provided with their full sphero-cylindrical over-refraction, compared to the LW group in their best spherical corrected contact lenses; subjective scores for vision were similar for the two groups. Bulbar conjunctival hyperaemia, limbal hyperaemia, corneal staining, conjunctival staining and papillary conjunctivitis were clinically equivalent for the two groups whereas conjunctival staining was higher in the LW group. Comfort scores assessed by SMS were equivalent for the LW and NLW groups; there was a measurable improvement in comfort during the first month of wear for the LW group.ConclusionThis work has demonstrated that modern soft lenses (narafilcon A daily disposable silicone hydrogel lenses) offer an excellent, comfortable form of vision correction, and are able to exhibit minimal alterations to ocular physiology.