Visual Performance of Four Simultaneous-Image Multifocal Contact Lenses Under Dim and Glare Conditions

BCLA CLEAR Presbyopia: Management with contact lenses and spectacles

This paper seeks to outline the history, market situation, clinical management and product performance related to the correction of presbyopia with both contact lenses and spectacles. The history of the development of various optical forms of presbyopic correction are reviewed, and an overview is presented of the current market status of contact lenses and spectacles. Clinical considerations in the fitting and aftercare of presbyopic contact lens and spectacle lens wearers are presented, with general recommendations for best practice. Current options for contact lens correction of presbyopia include soft simultaneous, rigid translating and rigid simultaneous designs, in addition to monovision. Spectacle options include single vision lenses, bifocal lenses and a range of progressive addition lenses. The comparative performance of both contact lens and spectacle lens options is presented. With a significant proportion of the global population now being presbyopic, this overview is particularly timely and is designed to act as a guide for researchers, industry and eyecare practitioners alike.

Content development for a new item-bank for measuring multifocal contact lens performance

BACKGROUND

Presbyopia is an age-related condition that causes a decreased ability to focus on nearby objects. Multifocal contact lenses are commonly used to address this issue. However, there seems to be a notable dissatisfaction among multifocal contact lens wearers. The absence of a reliable instrument to measure the patient's perspective, despite the widespread use of this method, highlights the need for further research in this area.

OBJECTIVE

The objective of this study is to develop an item-bank integrating all domains necessary to assess the patient's perspective on multifocal contact lens performance, offering a comprehensive measure. The item-bank will ensure a high level of content validity, be self-administered, and will initially be available in Spanish. The aim of this tool is to serve as a valuable resource for research and optometric clinics, facilitating the follow-up of patients with presbyopia who wear multifocal contact lenses or those who are newly starting to use them.

METHODOLOGY

The MCL-PRO item bank, followed a systematic and step-wise inductive approach to gather information, following the recommendations outlined in the COSMIN guidelines and similar studies. The process involved the following steps: (1) Literature review and relevant existing items identification (2) Social media review, (3) Semi-structured focus groups, (4) performing qualitative analysis, (5) refining and revising the items, and (6) generating the content of the item bank.

RESULTS

A total of 575 items were included in the item-bank hosted under 8 different domains that were found to be important for presbyopic population: visual symptoms (213), activity limitation (111), ocular symptoms (135), convenience (36), emotional well-being (33), general symptoms (16), cognitive issues (21) and economic issues (10).

CONCLUSION

The item-bank created has followed standardised methodology for its development and encloses all the aspects for MCL performance evaluation from patients perspective.

Clinical Outcomes of a Randomized Trial with Contact Lenses for Astigmatic Myopia Management

SIGNIFICANCE

There are limited treatment options for myopia management of patients with moderate to high astigmatism. This work directly compares toric orthokeratology and soft toric multifocal lenses to show differences in visual acuity and patient satisfaction that could impact clinical care. Toric orthokeratology caused reduced visual acuity but was preferred subjectively for vision and overall.

PURPOSE

This study aimed to quantify objective and subjective clinical differences between toric orthokeratology and soft toric multifocal contact lenses in the same cohort of myopic wearers with moderate to high astigmatism.

METHODS

Thirty adults with refractive myopia (plano to -5.00 D) and astigmatism (1.25 to 3.50 D) were fitted empirically with both toric orthokeratology and soft toric multifocal contact lenses. Participants wore lenses for 10 days in random order, separated by a 14-day washout period. High-contrast visual acuity, low-contrast visual acuity, and glare logMAR visual acuity were measured. Surveys ascertained subject preference for comfort, vision, handling, and cost. Friedman, Wilcoxon signed rank, and χ2 tests were performed.

RESULTS

A subset of participants (n = 17) who achieved good vision with both lens types was analyzed. High-contrast and glare acuity with toric orthokeratology were reduced by one line compared with soft toric multifocal lenses (both 0.00 vs. -0.10, P ≤ .003). Participants preferred toric orthokeratology for vision ( P ≤ .03) but soft toric multifocal lenses for handling ( P ≤ .006). When forced to choose between lens types, participants preferred toric orthokeratology for vision and overall (both P ≤ .007).

CONCLUSIONS

Participants who achieved good vision with both lens types preferred toric orthokeratology over soft toric multifocal lenses, despite reduced high-contrast and glare visual acuity. Further research is needed to understand the relationship between visual performance and patient satisfaction.

Short-term tear film stability, optical quality and visual performance in two dual-focus contact lenses for myopia control with different optical designs

Purpose

To assess and compare short‐term visual and optical quality and tear film stability between two dual‐focus (DF) prototype myopia control contact lenses (CLs) having different inner zone diameters.

Methods

Twenty‐eight myopic subjects were included in this randomised, double‐masked crossover study. Refraction, best‐corrected visual acuity (VA) and tear film stability were measured at baseline (i.e., when uncorrected). Subjects were then binocularly fitted with the DF CLs, with only the sensorial dominant eye being assessed. Lenses were of the same material and had inner zone diameters of either 2.1 mm (S design) or 4.0 mm (M design). Visual and physical short‐term lens comfort, over‐refraction, best‐corrected VA, stereopsis at 40 cm, best‐corrected photopic and mesopic contrast sensitivity (CS), size and shape of light disturbance (LD), wavefront aberrations, subjective quality of vision (QoV Questionnaire) and tear film stability were measured for each lens.

Results

Both CL designs decreased tear film stability compared with baseline (p < 0.05). VA and photopic CS were within normal values for the subjects' age with each CL. When comparing lenses, the M design promoted better photopic CS for the 18 cycles per degree spatial frequency (p < 0.001) and better LD (p < 0.02). However, higher‐order aberrations were improved with the S design (p = 0.02). No significant difference between the two CLs was found for QoV scores and tear film stability.

Conclusions

Both DF CLs provided acceptable visual performance under photopic conditions. The 4.0 mm inner zone gave better contrast sensitivity at high frequencies and lower light disturbance, while the 2.1 mm central diameter induced fewer higher‐order aberrations for a 5 mm pupil diameter. Both CLs produced the same subjective visual short‐term lens comfort.

Multifocal contact lenses: A bibliometric study

PURPOSE

To analyze the state of scientific publications in multifocal contact lenses field through a bibliometric study.

METHODS

The database used to carry out the study was SCOPUS and contained the descriptors "multifocal contact lens", "bifocal contact lenses", "progressive contact lenses" and "presbyopia contact lenses", limited to the fields of title, keywords and abstract. The indicators applied in this research were: doubling time and annual growth rate, Price's transience index, Lotka's law of scientific productivity, and Bradford's zones.

RESULTS

A total of 346 articles were published between 1960 and 2019. The growth in the number of publications matches the exponential adjustment slightly better (R = 0.53). The duplication time was 13.2 years. The productivity level is focused on articles with an average number of authors of just 2.06 per article. The Bradford core was formed by two journals, Optometry and Vision Science and Eye and Contact Lens.

CONCLUSIONS

Research on multifocal contact lenses has exponential growth, without evidence of having reached a saturation point. The main countries in scientific production in this field are the United States and Australia.

Effect of Contact Lenses on Contrast Sensitivity under Various Lighting Conditions

Purpose

To assess contrast sensitivity in clear and colored soft contact lenses under different lighting conditions.

Methods

This study was performed on 34 medical students. Visual acuity was measured using a tumbling E chart at a distance of 6 m, and contrast sensitivity was determined by Pelli Robson chart at a distance of 1 m. These tests were repeated in mesopic (3 lux) and glare (2000 lux) conditions. Then, a clear contact lens was applied to one eye and a colored contact lens was applied to the other. After 2 hr, visual acuity and contrast sensitivity were measured for each individual. The results were compared with and without contact lenses under normal, mesopic, and glare conditions.

Results

The mean refractive error was 0.44 ± 0.20 diopters. Repeated measures ANOVA showed a decline in contrast sensitivity with colored and clear contact lenses as compared to no-lens condition (P < 0.001). Additionally, lighting conditions had a significant impact on contrast sensitivity (P < 0.001); contrast sensitivity was lower in mesopic and glare conditions than under normal lighting condition.

Conclusion

In addition to the drop in contrast sensitivity under unusual lighting conditions (e.g., glare and mesopic), wearing soft contact lenses can further reduce contrast sensitivity in different lighting conditions. Therefore, people who wear contact lenses should be aware of this reduction in visual performance in conditions like driving at night or in the fog.

Comparison of visual performance between extended depth of focus contact lens and single-vision contact lens in eyes with monofocal intraocular lens

PURPOSE

To assess the visual performance of extended depth of focus (EDF) contact lenses (CL) in eyes that had undergone monofocal intraocular lens (IOL) implantation, and compare that between EDF and single-vision (SV) contact lenses.

STUDY DESIGN

Prospective, randomized, crossover study METHODS: Seventeen patients implanted with monofocal IOLs were enrolled. The study was conducted using 1dayPure EDOF as a test CL and 1dayPure moisture (both SEED Co., Ltd.) as a control CL. Binocular visual acuity from far to near distances, photopic and mesopic contrast sensitivity (with and without glare), and stereopsis were evaluated after wearing the two kinds of CLs in random order. The obtained results were compared between the EDF and SV CLs.

RESULTS

Binocular visual acuity at 0.3, 0.4, 0.7, 1, and 5 m was 0.24 ± 0.12, 0.07 ± 0.09, - 0.02 ± 0.08, - 0.02 ± 0.08, and - 0.06 ± 0.07 logMAR during the EDF CL wear, respectively, and 0.39 ± 0.17, 0.26 ± 0.15, 0.04 ± 0.12, - 0.02 ± 0.08, and - 0.09 ± 0.09 during the SV CL wear, respectively. The EDF CL showed better results than the SV CL at 0.3, 0.4, and 0.7 m (p < 0.05). There were no significant differences in contrast sensitivity between the EDF and SV CLs at 1.5 cycles per degree under all conditions; however, the sensitivity of the EDF CL was generally worse than that of the SV CL from the middle to high spatial frequencies. Stereopsis at 40 cm was significantly better in the EDF CL wear than in the SV CL wear (p < 0.05).

CONCLUSIONS

The EDF CL substantially improved visual acuity at near to intermediate distances in IOL-implanted eyes. However, far visual acuity decreased under low-contrast conditions, and contrast sensitivity slightly declined at the middle to high spatial frequencies.

Tear film stability over a myopia control contact lens compared to a monofocal design

Clinical relevance: Tear film assessment is essential in contact lens wearers and it can improve the success rates of the fitting.Background: To compare the short-term effect of two contact lenses on pre-lens tear film stability and comfort: dual-focus contact lens (MiSight) and a monofocal contact lens (Proclear 1-day).Methods: This randomised, double-masked, crossover study was performed in twenty-eight healthy, myopic volunteers aged between 18 and 32 years (23.5 ± 4.1 years). Only one randomly chosen eye was assessed. Distance vision and refraction were evaluated at baseline. Each contact lens type (monofocal and dual-focus) was randomly fitted, always in both eyes. A visual analogue scale between 0 and 10 was used to assess general comfort, physical comfort, and visual comfort. Tear Film Surface Quality (TFSQ) index, TFSQ_area and auto Tear Break-Up Time were obtained using Medmont E-300 at baseline (naked eye condition) and 25 minutes after each contact lens insertion.Results: Refractive sphere and cylinder were, respectively, -1.36 ± 1.04 D (ranging from -6.00 to -0.25 D) and -0.23 ± 0.30 D (ranging from -0.75 to 0.00 D). TFSQ and TFSQ area were lower (meaning more stable tear film) at baseline when compared with both contact lens types (p < 0.025). Higher pre-lens tear instability (larger TFSQ and_TFSQ area values) was found with the dual-focus than the monofocal lens. Auto Tear Break-Up Time was higher at baseline than with each of the contact lenses, without statistically significant differences between both contact lens types. Visual analogue scales revealed statistically significant better scores in the monofocal contact lens than in dual-focus contact lens for general (0.77 ± 1.14 vs 3.12 ± 2.79), physical (0.96 ± 1.46 vs 2.19 ± 2.45) and visual comfort (1.27 ± 1.66 vs 3.92 ± 2.04).Conclusion: A slight reduction in short-term pre-lens tear film stability was found in the dual-focus design in comparison with the monofocal lens, potentially contributing to the deterioration of visual performance and comfort during dual-focus contact lens wear.

Visual Performance of Center-distance Multifocal Contact Lenses Fit Using a Myopia Control Paradigm

PURPOSE

The purpose of this study was to examine the visual performance of center-distance MFCLs in nonpresbyopic adults under different illumination and contrast conditions compared with a single-vision contact lens (SVCL).

METHODS

Twenty-five adult subjects were fit with three different lenses (CooperVision Biofinity D MFCL +2.50 add, Visioneering Technologies NaturalVue MFCL, CooperVision Biofinity sphere). Acuity and reading performance were evaluated.

RESULTS

A statistically significant difference in high-contrast distance acuity was observed (Biofinity, -0.18 ± 0.06; Biofinity MFCL, -0.14 ± 0.08; NaturalVue MFCL, -0.15 ± 0.03; repeated-measures [RM] ANOVA, P = .02). Under mesopic, high-contrast conditions, MFCLs performed worse than SVCLs (Biofinity, -0.05 ± 0.091; Biofinity MFCL, +0.03 ± 0.09; NaturalVue MFCL, +0.05 ± 0.091; RM-ANOVA, P < .0001). Under low-contrast conditions, MFCLs performed one line worse in photopic lighting and two lines worse under mesopic conditions (RM-ANOVA, P < .0001). Glare reduced acuity by 0.5 logMAR for all lenses (RM-ANOVA, P < .001). A statistically significant difference in near acuity was observed (RM-ANOVA, P = .02), but all lenses achieved acuity better than -0.1 logMAR (Biofinity, -0.16 ± 0.06; Biofinity MFCL, -0.17 ± 0.04; NaturalVue MFCL, -0.13 ± 0.08). Reading performance in words per minute (wpm) was worse with MFCLs (Biofinity MFCL, 144 ± 22 wpm; NaturalVue MFCL, 150 ± 28 wpm) than with SVCLs (156 ± 23 wpm; RM-ANOVA, P = .02) regardless of letter size (RM-ANOVA, P = .13). No difference in acuity between the MFCLs was detected (RM-ANOVA: all, P > .05).

CONCLUSIONS

Multifocal contact lenses perform similarly to SVCLs for high-contrast targets and display reduced low-contrast acuity and reading speed. Practitioners should recognize that high-contrast acuity alone does not describe MFCL visual performance.

Visual function, ocular surface integrity and symptomatology of a new extended depth-of-focus and a conventional multifocal contact lens

PURPOSE

To evaluate visual function, ocular surface integrity and dry eye symptoms with an extended depth-of-focus (EDOF) design and a conventional multifocal (MF) contact lens (CL) after 15 days of wear.

METHODS

A crossover single mask randomised clinical trial was conducted including 30 presbyopes who used an EDOF and a conventional MF CL (Biofinity MF) for 15 days each. Defocus curves, depth-of-focus range, contrast sensitivity (CS) under photopic and mesopic conditions (with and without glare) and subjective perception of halos and glare were evaluated. The ocular surface was evaluated through non-invasive Keratograph tear breakup time (NIKBUT), averaged tear breakup time (NIKBUT-avg), tear meniscus height (TMH), bulbar and limbal redness, and conjunctival and corneal staining. Dry eye symptoms were assessed with the OSDI questionnaire.

RESULTS

No statistically significant differences were found for defocus curves or depth-of-focus between the two CLs (both p > 0.05). Subjective perception of halos and glare was not significantly different between CLs. Statistically significant differences were observed for CS under mesopic conditions for low spatial frequencies (p = 0.008). None of the CL produced significant changes in NIKBUT, NIKBUT-avg, TMH or redness. No change in conjunctival staining was observed in 76.7 % and 73.3 % of participants for EDOF and Biofinity MF, respectively. No change in corneal staining was observed in 86.7 % and 83.3 % of participants for EDOF and Biofinity MF, respectively. No changes were observed in the symptomatology measured with OSDI questionnaire (p > 0.05).

CONCLUSIONS

Both CL for presbyopia offer good visual quality, preserve the ocular surface integrity and provide the patient with similar symptomatology levels after 15 days of lens wear.

Visual Performance of Daily-disposable Multifocal Soft Contact Lenses: A Randomized, Double-blind Clinical Trial

SIGNIFICANCE

The present study highlights the differences between modern daily-disposable multifocal soft contact lenses to assist eye care practitioners in fitting presbyopic contact lens wearers.

PURPOSE

The purpose of this study was to compare visual performance of three daily-disposable multifocal contact lenses.

METHODS

Presbyopes (n = 72) wore 1-Day Acuvue Moist Multifocal, BioTrue ONEday for Presbyopia, and Dailies AquaComfort Plus Multifocal for 1 week in a prospective, randomized, double-blind, crossover clinical trial. After 1 week, high- and low-contrast visual acuities (HCVA, LCVA) were measured between 6 m and 40 cm and stereopsis at 40 cm. Subjective performance was assessed with 1- to 10-point rating scales for clarity, ghosting, driving vision, vision stability, ease of focusing, overall vision satisfaction, and ocular comfort. Willingness to purchase was reported with categorical responses. Linear mixed models and χ tests were used for analysis, and level of significance was set at 5%.

RESULTS

BioTrue provided better HCVA and LCVA at distance than did Acuvue Moist (P ≤ .03). Subjectively, Acuvue Moist was rated lowest for distance clarity, distance ghosting, and driving vision (P ≤ .05). Acuvue Moist provided better HCVA at 70 to 40 cm and LCVA at 1 m to 40 cm than did BioTrue (P ≤ .01) and better LCVA at 1 m to 50 cm than did AquaComfort Plus (P ≤ .02). AquaComfort Plus also provided better HCVA and LCVA at 50 and 40 cm than did BioTrue (P ≤ .03). Acuvue Moist provided better stereopsis than did BioTrue (P = .02). Subjectively, BioTrue was rated lowest for near clarity (P ≤ .007) and lower than Acuvue Moist for intermediate clarity and near ghosting (P ≤ .04). No other differences were found between lenses (P > .05).

CONCLUSIONS

BioTrue had better distance performance compared with near, whereas Acuvue Moist performed conversely. AquaComfort Plus performed reasonably overall.

Predicting Short-Term Subjective Vision Performance of Contact Lenses Used in Myopia Control

OBJECTIVE

To investigate whether initial assessment of contact lenses prescribed for myopia control (MC) predicts short-term visual performance.

METHOD

Retrospective analysis of 43 participants in a double-masked, randomized, cross-over trial wearing at least one lens: single-vision (SV) lens (1-DAY ACUVUE MOIST) or MC lenses (MiSight or Proclear Multifocal-Distance +2.00D). Participants completed questionnaires at the fitting visit, a take-home questionnaire (THQ) 3 days after fitting and finally at the assessment visit (≥5 days after fitting). Questions comprised vision clarity and lack of ghosting (distance, intermediate, near at day/night time); vision stability; driving vision; overall vision satisfaction and comfort (1-10 scale, 1-point steps); and willingness to purchase based on vision and MC benefit of lens (yes/no response). Visual acuity was measured at fitting and assessment visits.

RESULTS

Vision clarity (intermediate and near) was significantly worse at assessment compared with fitting while wearing MC lenses (P<0.001), as was overall vision satisfaction (P<0.001), comfort (P<0.001), and vision stability (P=0.001) while wearing either SV or MC lenses. Participants willing to purchase at assessment visit was 84% with SV and 36% with MC lenses, increasing to 88% (SV, P=1.00) and 61% (MC, P<0.001) if the lenses slowed myopia progression. Visual acuity was no different with either MC or SV lenses at fitting or assessment (P≥0.251).

CONCLUSION

Initial performance at fitting did not predict short-term performance for SV or MC lenses. A significant increase in willingness to purchase if lenses slowed myopia progression was observed while wearing MC lenses. Educating patients on the benefits might increase acceptability of MC lenses.

Extended depth of focus contact lenses vs. two commercial multifocals: Part 1. Optical performance evaluation via computed through-focus retinal image quality metrics

PURPOSE

To compare the computed optical performance of prototype lenses designed using deliberate manipulation of higher-order spherical aberrations to extend depth-of-focus (EDOF) with two commercial multifocals.

METHODS

Emmetropic, presbyopic, schematic eyes were coupled with prototype EDOF and commercial multifocal lenses (Acuvue Oasys for presbyopia, AOP, Johnson & Johnson & Air Optix Aqua multifocal, AOMF, Alcon). For each test configuration, the through-focus retinal image quality (TFRIQ) values were computed over 21 vergences, ranging from -0.50 to 2.00D, in 0.125D steps. Analysis was performed considering eyes with three different inherent aberration profiles: five different pupils and five different lens decentration levels.

RESULTS

Except the LOW design, the AOP lenses offered 'bifocal' like TFRIQ performance. Lens performance was relatively independent to pupil and aberrations but not centration. Contrastingly, AOMF demonstrated distance centric performance, most dominant in LOW followed by MED and HIGH designs. AOMF lenses were the most sensitive to pupil, aberrations and centration. The prototypes demonstrated a 'lift-off' in the TFRIQ performance, particularly at intermediate and near, without trading performance at distance. When compared with AOP and AOMF, EDOF lenses demonstrated reduced sensitivity to pupil, aberrations and centration.

CONCLUSION

With the through focus retinal image quality as the gauge of optical performance, we demonstrated that the prototype EDOF designs were less susceptible to variations in pupil, inherent ocular aberrations and decentration, compared to the commercial designs. To ascertain whether these incremental improvements translate to a clinically palpable outcome requires investigation through human trials.

Extended depth of focus contact lenses vs. two commercial multifocals: Part 2. Visual performance after 1 week of lens wear

PURPOSE

To compare the visual performance of prototype contact lenses designed via deliberate manipulation of higher-order spherical aberrations to extend-depth-of-focus with two commercial multifocals, after 1 week of lens wear.

METHODS

In a prospective, participant-masked, cross-over, randomized, 1-week dispensing clinical-trial, 43 presbyopes [age: 42-63 years] each wore AIROPTIX Aqua multifocal (AOMF), ACUVUE OASYS for presbyopia (AOP) and extended-depth-of-focus prototypes (EDOF) appropriate to their add requirements. Measurements comprised high-contrast-visual-acuity (HCVA) at 6m, 70cm, 50cm and 40cm; low-contrast-visual-acuity (LCVA) and contrast-sensitivity (CS) at 6m and stereopsis at 40cm. A self-administered questionnaire on a numeric-rating-scale (1-10) assessed subjective visual performance comprising clarity-of-vision and lack-of-ghosting at various distances during day/night-viewing conditions and overall-vision-satisfaction.

RESULTS

EDOF was significantly better than AOMF and AOP for HCVA averaged across distances (p≤0.038); significantly worse than AOMF for LCVA (p=0.021) and significantly worse than AOMF for CS in medium and high add-groups (p=0.006). None of these differences were clinically significant (≤2 letters). EDOF was significantly better than AOMF and AOP for mean stereoacuity (36 and 13 seconds-of-arc, respectively: p≤0.05). For clarity-of-vision, EDOF was significantly better than AOP at all distances and AOMF at intermediate and near (p≤0.028). For lack-of-ghosting averaged across distances, EDOF was significantly better than AOP (p<0.001) but not AOMF (p=0.186). EDOF was significantly better than AOMF and AOP for overall-vision-satisfaction (p≤0.024).

CONCLUSIONS

EDOF provides better intermediate and near vision performance than either AOMF or AOP with no difference for distance vision after 1 week of lens wear.

Fitting success for three multifocal designs: Multicentre randomised trial

PURPOSE

To determine if the discontinuation of commercially-available simultaneous vision Multifocal Soft Contact Lenses is independent from the multifocal design. To determine causes for discontinuation and psychosocial factors involved.

METHODS

Multicentre single-blinded randomised controlled trial with external blinded evaluation for a three months follow-up period for three intervention groups. 150 single-vision soft wearers were randomly assigned a spherical near centred lens (S-CN), distance centred lens (CD) or aspherical near centred lens (A-CN). Cases of discontinuation, anxiety and quality of life were measured at one week and one month.

RESULTS

120 females and 30 males were included with an age range of 40-62 (48.79 ± 5.23). At one month, the S-CN design had a statistically significant higher risk of discontinuation than the other two OR: 6.12 (95%CI 2.5-14.9). Twenty-eight subjects discontinued wearing S-CN at first week (56%), while discontinuation of CD and A-CD were 15 (30%) and 11 (22%), with a statistically significant difference between S-CN design and the other two (p = 0.001). There were not statistically significant differences when direct comparison between discontinuation of CD and A-CN was made (p = 0.36). Thirty-two percent discontinued the use because of poor distance vision and 28% because of both poor distance and near vision. Psychosocial factors were not statistically significant.

CONCLUSIONS

Discontinuation of Multifocal Soft Contact Lenses is dependent on the design. Most common cause for discontinuation is poor distance vision. Psychosocial factors do not impact on discontinuation rates.

Disability glare in soft multifocal contact lenses

PURPOSE

The study investigated the effect of the design of multifocal contact lenses on the sensitivity to contrast and disability glare.

METHODS

Contrast sensitivity was measured in 16 young adults (mean age: 25.5±2.5years) at a distance of 2m under two conditions: no-glare and glare. Two designs (Center Near and Center Distance) of the Biofinity soft contact lens were used to simulate correction for presbyopes, while a correction with single vision trial lenses and contact lenses acted as controls.

RESULTS

The design of the used multifocal contact lenses had a significant influence on the log area under the curve of the contrast sensitivity function (AUC-CSF). Compared to the spectacle lens correction, the AUC-CSF was significantly reduced, in case CS was measured with the Center Near design lens, under the no-glare (p<0.001) and the glare condition (p: p<0.001). In case of the Center Distance design contact lens, the AUC-CSF was significantly smaller in case CS was tested under glare (p=0.001). Disability glare (DG) was depending on the spatial frequency and the design of the multifocal lens, while the Center Distance design produced higher amounts of DG (p<0.001), compared to the other used corrections.

CONCLUSION

The optical design of a multifocal contact lenses has a significant impact on the contrast sensitivity as well as the disability glare. In order to dispense the best correction in terms of contact lenses, the sensitivity to contrast under no-glare and glare conditions should be tested a medium spatial frequencies.

A Survey of Presbyopic Contact Lens Wearers in a University Setting

PURPOSE

To determine why presbyopic patients discontinue contact lens wear and describe their opinions of comfort and visual quality with contact lenses.

METHODS

A survey assessing current age, gender, contact lens material/design, and opinions of contact lens comfort and visual quality was mailed to 2400 presbyopic patients (age 40 years and older) that have had eye exams in the Ohio State University College of Optometry's Contact Lens Services over the last 4 years.

RESULTS

A total of 496 surveys were analyzed. The mean age of survey respondents was 57 ± 9 years, and 68% of the sample was female. Permanent discontinuation of contact lens wear was reported by 15%. No association was found between contact lens discontinuation and age (p = 0.7), gender (p = 0.2), age of beginning contact lens wear (p = 0.1), or contact lens material (p = 0.1). Poor vision (38%), discomfort (34%), convenience (20%), and cost (6%) were the primary reported reasons for discontinuation. There was no difference between the proportion of subjects reporting "poor vision" as their primary discontinuation reason and those reporting "discomfort" (p = 0.7). Discontinued wearers had a worse overall opinion of their distance (p = 0.03), intermediate (p = 0.01), and near vision (p = 0.002) compared to subjects who were still wearing their contact lenses.

CONCLUSIONS

Discomfort has been reported as the primary reason for contact lens discontinuation. In this presbyopic population, dissatisfaction with vision and discomfort were reported equally as often as primary reasons for discontinuation. As well, subjects who ceased contact lens wear had worse overall opinions of their vision at all distances than current contact lens wearers. The results of this survey suggest that presbyopes have unique demands and opinions related to contact lens wear.

Objective assessment of the effect of pupil size upon the power distribution of multifocal contact lenses

AIM

To analytically assess the effect of pupil size upon the refractive power distributions of different designs of multifocal contact lenses.

METHODS

Two multifocal contact lenses of center-near design and one multifocal contact lens of center-distance design were used in this study. Their power profiles were measured using the NIMO TR1504 device (LAMBDA-X, Belgium). Based on their power profiles, the power distribution was assessed as a function of pupil size. For the high addition lenses, the resulting refractive power as a function of viewing distance (far, intermediate, and near) and pupil size was also analyzed.

RESULTS

The power distribution of the lenses was affected by pupil size differently. One of the lenses showed a significant spread in refractive power distribution, from about -3 D to 0 D. Generally, the power distribution of the lenses expanded as the pupil diameter became greater. The surface of the lens dedicated for each distance varied substantially with the design of the lens.

CONCLUSION

In an experimental basis, our results show how the lenses power distribution is affected by the pupil size and underlined the necessity of careful evaluation of the patient's visual needs and the optical properties of a multifocal contact lens for achieving the optimal visual outcome.

Short-term comparison between extended depth-of-focus prototype contact lenses and a commercially-available center-near multifocal

PURPOSE

To compare the visual performance of prototype contact lenses which extend depth-of-focus (EDOF) by deliberate manipulation of multiple higher-order spherical aberration terms and a commercially-available center-near lens (AIR OPTIX Aqua Multifocal, AOMF).

METHODS

This was a prospective, cross-over, randomized, single-masked (participant), short-term clinical trial where 52 participants (age 45-70 years) were stratified as low, medium or high presbyopes and wore EDOF and AOMF on different days. Objective measures comprised high and low contrast visual acuity (HCVA/LCVA, logMAR), and contrast sensitivity (log units) at 6m; HCVA at 70cm, 50cm and 40cm and stereopsis (seconds of arc) at 40cm. HCVA at 70cm, 50cm and 40cm were measured as "comfortable acuity" rather than conventional resolution acuity. Subjective measures comprised clarity-of-vision and ghosting at distance, intermediate and near, overall vision satisfaction and ocular comfort (1-10 numeric rating scale) and lens purchase (yes/no response). Statistical analysis included repeated measures ANOVA, paired t-tests and McNemar's test.

RESULTS

Significant differences between lens types were independent of strata (p≥0.119). EDOF was significantly better than AOMF for HCVA at 40cm (0.42±0.18 vs. 0.48±0.22, p=0.024), stereopsis (98±88 vs. 141±114, p<0.001), clarity-of-vision at intermediate (8.5±1.6 vs. 7.7±1.9, p=0.006) and near (7.3±2.5 vs. 6.2±2.5, p=0.005), lack-of-ghosting (p=0.012), overall vision satisfaction (7.5±1.7 vs. 6.4±2.2, p<0.001) and ocular comfort (9.0±1.0 vs. 8.3±1.7, p=0.002). Significantly more participants chose to only-purchase EDOF (33% vs. 6%, p=0.003).). There were no significant differences between lens types for any objective measure at 6m or clarity-of-vision at distance (p≥0.356).

CONCLUSIONS

EDOF provides better intermediate and near vision performance in presbyopes than AOMF with no difference for distance vision during short-term wear.

Refractive errors

BACKGROUND

All over the world, refractive errors are among the most frequently occuring treatable distur - bances of visual function. Ametropias have a prevalence of nearly 70% among adults in Germany and are thus of great epidemiologic and socio-economic relevance.

METHODS

In the light of their own clinical experience, the authors review pertinent articles retrieved by a selective literature search employing the terms "ametropia, "anisometropia," "refraction," "visual acuity," and epidemiology."

RESULTS

In 2011, only 31% of persons over age 16 in Germany did not use any kind of visual aid; 63.4% wore eyeglasses and 5.3% wore contact lenses. Refractive errors were the most common reason for consulting an ophthalmologist, accounting for 21.1% of all outpatient visits. A pinhole aperture (stenopeic slit) is a suitable instrument for the basic diagnostic evaluation of impaired visual function due to optical factors. Spherical refractive errors (myopia and hyperopia), cylindrical refractive errors (astigmatism), unequal refractive errors in the two eyes (anisometropia), and the typical optical disturbance of old age (presbyopia) cause specific functional limitations and can be detected by a physician who does not need to be an ophthalmologist.

CONCLUSION

Simple functional tests can be used in everyday clinical practice to determine quickly, easily, and safely whether the patient is suffering from a benign and easily correctable type of visual impairment, or whether there are other, more serious underlying causes.

Short-Term Visual Performance of Novel Extended Depth-of-Focus Contact Lenses

PURPOSE

To compare the objective and subjective visual performance of a novel contact lens which extends depth of focus by deliberate manipulation of higher-order spherical aberrations and a commercially available zonal-refractive multifocal lens.

METHODS

A prospective, cross-over, randomized, single-masked, short-term clinical trial comprising 41 presbyopes (age 45 to 70 years) wearing novel Extended Depth of Focus lenses (EDOF) and ACUVUE OAYS for Presbyopia (AOP). Each design was assessed on different days with a minimum overnight wash-out. Objective measures comprised high-contrast visual acuity (HCVA, logMAR) at 6 m, 70 cm, 50 cm, and 40 cm; low-contrast visual acuity (LCVA, logMAR) and contrast sensitivity (log units) at 6 m; and stereopsis (seconds of arc) at 40 cm. HCVA at 70 cm, 50 cm, and 40 cm were measured as "comfortable acuity" rather than conventional resolution acuity. Subjective performance was assessed on a 1-10 numeric rating scale for clarity of vision and ghosting at distance, intermediate and near, overall vision satisfaction, ocular comfort, and lens purchase. Statistical analysis included repeated measures ANOVA and paired t tests.

RESULTS

HCVA, clarity of vision, and ghosting with EDOF were significantly better than AOP (p < 0.01); however, differences were dependent on testing distances and add groups. Post hoc analysis showed EDOF was significantly better than AOP for HCVA at 70 cm (0.11 ± 0.11 vs. 0.21 ± 0.16, p < 0.001), 50 cm (0.26 ± 0.17 vs. 0.36 ± 0.18, p = 0.003), 40 cm (0.42 ± 0.17 vs. 0.52 ± 0.21, p = 0.001), and LCVA at 6 m (0.22 ± 0.08 vs. 0.27 ± 0.12, p = 0.024). EDOF was significantly better than AOP for clarity of vision at distance (7.7 ± 1.6 vs. 6.8 ± 2.3, p = 0.029), intermediate (8.8 ± 1.4 vs. 7.0 ± 2.2, p < 0.001), and near (7.4 ± 2.4 vs. 5.2 ± 2.7, p < 0.001), ghosting at distance (9.1 ± 1.2 vs. 8.1 ± 2.5, p = 0.005), and overall vision satisfaction (7.6 ± 1.6 vs. 6.0 ± 2.6, p < 0.001). More participants chose to purchase EDOF compared to AOP (61 vs. 39%) and significantly more chose to only-purchase EDOF compared to only-purchase AOP (27 vs. 5%, p = 0.022).

CONCLUSIONS

When compared with AOP, EDOF lenses provide better intermediate and near vision performance in presbyopic participants without compromising distance vision.