Effect of presbyopic vision corrections on perceptions of driving difficulty

Improving the performance of multifocal diffractive lens designs by adding a peripheral piston

Peripheral piston modulation in diffractive multifocal lenses suggests potential improvements in distance vision quality. Five lens designs-bifocal (BF), bifocal with piston (BFP), trifocal (TF), trifocal with piston (TFP), and a commercial refractive (RCN)-were compared using an adaptive optics visual simulator. Optical simulations revealed enhanced optical quality for distant objects with peripheral pistons, without compromising near vision. Visual performance and quality were assessed in eight cycloplegic young subjects. The peripheral piston was associated with trends toward improved high- and low-contrast visual acuity and visual preference scores at distance, suggesting functional and perceptual benefits over non-piston designs.

Development and Validation of a Novel Night-Time Hazard Visibility Test

Purpose

Night-time driving is dangerous, with increased crash rates, particularly involving vulnerable road users. A Night-Time Hazard Visibility Test (NHVT) was developed and validated by exploring the effects of refractive and cataract blur on performance.

Methods

The NHVT comprised video clips of night-time roads from the driver's perspective, including different hazards (pedestrians, cyclists, and vehicles). Participants responded when they first recognized hazards requiring them to take evasive action to avoid a collision. In experiment 1, there were 16 young visually normal drivers (mean age = 22.3, standard deviation [SD] = 2.2 years) who completed 2 NHVT sets, viewed separately through best-correction and refractive blur (+1.00 diopter sphere [DS]). In experiment 2, a refined version of the NHVT was administered to an additional 16 young visually normal drivers (mean age = 21.1, SD = 1.2 years) with best-correction and cataract blur. The order of visual conditions and NHVT sets were counterbalanced.

Results

In experiment 1, refractive blur significantly reduced photopic visual acuity (VA) compared to best-corrected vision (+0.09 vs. -0.21 logMAR, P < 0.001) and delayed response times by 0.69 seconds (3.10 vs. 2.41 seconds, P < 0.001) compared to best-corrected vision. In experiment 2, cataract blur reduced VA compared to best-corrected vision (+0.03 vs. -0.17 logMAR, P < 0.001) and delayed response times by 0.63 seconds (2.92 vs. 2.29 seconds, P < 0.001).

Conclusions

The NHVT was sensitive to refractive and cataract blur, providing preliminary support of its validity as a measure of night-time hazard visibility performance.

Translational Relevance

The NHVT has potential as an off-road assessment of visibility for night driving and application for assessment of drivers with different refractive corrections and ocular diseases.

Laser refractive correction of presbyopia

Presbyopia is an inevitable and progressive loss of the eye's ability to focus on nearby objects due to aging, which affects everyone regardless of their refractive error. Uncorrected presbyopia is a significant burden worldwide and affects the quality of life. Conservative options include spectacle correction, contact lenses, and pharmacologic agents. Spectacles are commonly used to correct vision, but have certain drawbacks such as peripheral blur and impaired depth perception. These limitations have been associated with an increased risk of accidental falls. Several surgical options are available to address these issues, including cornea-based, lens-based, or scleral procedures. These procedures involve modifying the cornea's optics, replacing the crystalline lens, or attempting to restore accommodation. Each of the options has its benefits and limitations. One of the most common surgical methods of presbyopic correction that has recently become popular is presbyopic Laser assisted In situ keratomileusis (LASIK) due to its improved safety and efficacy. This article is a review of all the currently available data and studies regarding the various methods of correction of presbyopia, with an emphasis on the principles and outcomes of the corneal laser refractive procedures for presbyopia correction, such as PresbyLASIK, Supracor, PRESBYOND laser blended vision, and Custom Q.

Impact of presbyopia treatment pilocarpine hydrochloride 1.25% on night-driving performance

CLINICAL RELEVANCE

Patients prescribed pilocarpine ophthalmic solution are advised to be cautious when driving at night, but studies evaluating the effects of pilocarpine hydrochloride ophthalmic solution 1.25% (pilo), approved to treat presbyopia, on driving at night are lacking.

BACKGROUND

This double-masked, crossover, phase 3b study evaluated night-driving performance with pilo or the placebo once daily.

METHODS

Forty-three adults (40-55 years) with presbyopia impacting daily activities and mesopic, high-contrast, binocular distance-corrected near vision 6/12-6/30 were randomised to bilateral treatment with pilo followed by placebo or placebo followed by pilo (with a ≥7-day washout between interventions). Night-driving performance was evaluated at twilight at a closed-circuit course. Primary efficacy endpoint: overall composite night-driving performance Z score at the end of the 7-14-day intervention period, 1 hour post-instillation. Pilo was considered non-inferior if the lower limit of the 95% confidence interval (CI) for the least squares mean difference (LSMD, pilo minus placebo) was >-0.25. Other efficacy endpoints: individual components of the night-driving performance test (hazard avoidance rate; road sign recognition rate and distance; pedestrians recognition distance; overall driving and lane-keeping times) and night-driving experience questionnaire. Safety included treatment-emergent adverse events (TEAEs).

RESULTS

The mean overall composite Z scores were -0.121 (pilo) and 0.118 (placebo). The LSMD (pilo minus placebo) was -0.224 (95% CI, -0.346, -0.103), with 3 of the 7 individual tasks being significantly better with the placebo. The questionnaire did not reveal significant differences between pilo and the placebo. There were no serious or severe TEAEs and no TEAE-related discontinuations. The most common ocular TEAEs were headache and visual impairment with pilo (both 27.9%), and dry eye (7.0%) with the placebo.

CONCLUSION

The overall performance of night driving was inferior with pilo, compared with placebo. The study findings are consistent with the current class labelling and provide evidence to inform regulators and assist clinicians considering prescribing pilo to adults who seek treatment of presbyopia symptoms and drive at night.ClinicalTrials.gov identifier: NCT04837482.

Driving performance and road sign identification by multifocal contact lens wearers in a driving simulator

PURPOSE

The purpose of this study was to compare sign identification distances and driving performance metrics in presbyopic participants while wearing multifocal contact lenses (MFCL) and while wearing progressive addition lens (PAL) spectacles.

METHODS

19 presbyopic participants completed PAL spectacle assessments and contact lens fitting and follow up visits before driving assessments began. These assessments occurred in a simulator equipped with a full-sized sedan on a motion platform and a 260 degree screen. Participants completed the driving task with PAL and with MFCL. Participants followed a lead car and identified signs at various distances from the road. For the two wearing conditions, comparisons of the distance along the road at which signs were identified were made using repeated measures ANOVA. Paired t-tests were used to compare driving performance for the two conditions.

RESULTS

There was no statistical difference in sign identification distance between PAL and MFLC for signs 32.0 m from the road side of the road (182 ± 46 m for MFCL; 205 ± 45 m for PAL; P = 0.07) or 51.4 m from the side of the road (204 ± 43 m for MFCL; 216 ± 36 m for PAL; P = 0.3). Only signs 70.2 m from the roadside showed a significant difference (207 ± 42 m with MFCL; 232 ± 39 m with PAL; P = 0.01), All distances were greater than those required to safely stop a vehicle. There were no significant differences in the driving performance metrics between the refractive corrections.

CONCLUSION

Driving performance metrics were similar for MFCL and PAL spectacles. Sign identification distances with both eyewear types were well within the distances required for safe vehicle stopping.

Presbyopia - A Review of Current Treatment Options and Emerging Therapies

Presbyopia is a common age-related vision disorder characterized by a progressive inability to focus on near objects. If uncorrected or under-corrected, presbyopia can significantly impact patients' quality of life. Presbyopia represents an area of considerable unmet need due to its rising prevalence worldwide as the population ages, the high proportion of under-treated individuals in some parts of the world, and the limitations of currently available corrective methods. Progressive or bifocal spectacles are associated with peripheral blur, a restricted visual field and impaired depth perception, which have been linked to an increased risk of falls in the elderly. Contact lens options can be difficult to maintain due to the development of age-related dry eye symptoms and reduced manual dexterity. Other corrective methods involve surgical interventions that modify the optics of the cornea, replace the crystalline lens, or attempt to restore active accommodation. While patients undergoing surgery report satisfactory outcomes post-operatively, many of them eventually require reading glasses. Non-invasive therapies with novel mechanisms of action are currently being investigated; these include miotic agents and UNR844, a lipoic acid choline ester. In this narrative review, available evidence on presbyopia prevalence, quality of life impact and risk factors are described, with a focus on observational studies in non-clinical settings. The diagnosis pathway and patient journey in presbyopia are outlined, and various treatment options are analyzed. The data reviewed herein reveals significant gaps in the provision of vision correction for this common condition, with a paucity of effective, non-invasive treatment options broadly accessible to presbyopic individuals.

Quality of Life in Presbyopes with Low and High Myopia Using Single-Vision and Progressive-Lens Correction

This study evaluates the impact of the severity of myopia and the type of visual correction in presbyopia on vision-related quality of life (QOL), using the refractive status and vision profile (RSVP) questionnaire. A total of 149 subjects aged 41-75 years with myopic presbyopia were recruited: 108 had low myopia and 41 had high myopia. The RSVP questionnaire was administered. Rasch analysis was performed on five subscales: perception, expectation, functionality, symptoms, and problems with glasses. Highly myopic subjects had a significantly lower mean QOL score (51.65), compared to low myopes (65.24) (p < 0.001). They also had a significantly lower functionality score with glasses (49.38), compared to low myopes (57.00) (p = 0.018), and they had a worse functionality score without glasses (29.12), compared to low myopes (36.24) (p = 0.045). Those who wore progressive addition lenses (PAL) in the high-myope group (n = 25) scored significantly better, compared to those who wore single-vision distance (SVD) lenses (n = 14), with perception scores of 61.19 and 46.94, respectively (p = 0.029). Highly myopic presbyopes had worse overall QOL and functionality, both with and without glasses, compared to presbyopes with low myopia. High-myopic PAL users had a better perception outcome than SVD lens wearers. Low-myopic PAL wearers had a better QOL than SVD wearers.

Visual Perception: Monovision Can Bias the Apparent Depth of Moving Objects

'Monovision' - using one eye for near work and one for distance - is a common alternative to reading glasses. New work shows that monovision can cause the distance of moving objects to be misestimated, with potentially serious consequences.

Light distortion of soft multifocal contact lenses with different pupil size and shape

PURPOSE

To study the light distortion effects of soft multifocal contact lenses and the influence of different pupil size and shape.

METHODS

A total of 14 eyes of 7 healthy contact lens users (mean age 28.6 ± 8.5 years) were recruited. The "Light Disturbance Analyser" device was employed for light characterization. The selected lenses were the monthly disposable "Biofinity multifocal" (CooperVision, CA, USA), both centre-distance and centre-near designs (addition power +2.50 D). Two circular pupils of 3 mm and 5 mm of diameter, and an elliptical shape (3 horizontal and 5 vertical mm) were used. Metrics such as the light distortion index (LDI), best-fit circle radius and its irregularity were analysed, among others.

RESULTS

The LDI was generally higher with multifocal lenses, varying from 3.7 ± 0.3 % of the single vision lens to 6.1 ± 3.3 % of the multifocal centre-distance design and the 5-mm pupil. Larger pupils gave higher LDI values, changing from 4.5 ± 2.0 % (3 mm) to 6.1 ± 3.3 % (5 mm) with the centre-distance design. The elliptical pupil produced the largest discrepancy in the distortion size between the vertical and horizontal directions. The centre-distance and centre-near designs behaved similarly in terms of light distortion.

CONCLUSIONS

The multifocal contact lenses of the study increased light distortion effects under low light conditions, especially with larger pupils. The shape of the distortion pattern is associated with the shape of the pupil. It seems that not all, but a big percentage of light distortion would be produced by the presence of the out-of-focus images given by a multifocal lens.

Presbyopic Excimer Laser Ablation: A Review

PURPOSE

To provide an overview of the efficacy and safety of available presbyopic excimer laser ablation profiles.

METHODS

Literature review.

RESULTS

Monovision with excimer laser traditionally applies near correction to the non-dominant eye. Different excimer laser presbyopic approaches include the increase in depth of focus, through the controlled change of spherical aberration or asphericity, or multifocal ablation patterns with central or peripheral near vision zones. The studies investigating different excimer laser ablation patterns applied in previously myopic eyes revealed high levels of efficacy with all ablation profiles (between 68% and 99% achieving binocular uncorrected distance visual acuity [UDVA] of 20/25 or better, and between 70% and 100% achieving uncorrected near visual acuity [UNVA] presenting J3 or better). In hypermetropic eyes, most of the studies revealed high levels of efficacy with different platforms (between 78% and 100% achieving binocular UDVA of 20/25 or better and between 70% and 100% achieving UNVA presenting J3 or better). Loss of two or more lines of corrected distance visual acuity varied between 0% and 10% in the myopic eyes and between 0% and 14% in the hyperopic eyes.

CONCLUSIONS

There is evidence that excimer laser presbyopic strategies accomplish spectacle independence at reasonable levels. There are reliable and safe options for both myopic and hyperopic eyes with satisfactory outcomes regarding near and distance vision. [J Refract Surg. 2018;34(10):698-710.].

Presbyopia: Effectiveness of correction strategies

Presbyopia is a global problem affecting over a billion people worldwide. The prevalence of unmanaged presbyopia is as high as 50% of those over 50 years of age in developing world populations, due to a lack of awareness and accessibility to affordable treatment, and is even as high as 34% in developed countries. Definitions of presbyopia are inconsistent and varied, so we propose a redefinition that states "presbyopia occurs when the physiologically normal age-related reduction in the eye's focusing range reaches a point, when optimally corrected for distance vision, that the clarity of vision at near is insufficient to satisfy an individual's requirements". Strategies for correcting presbyopia include separate optical devices located in front of the visual system (reading glasses) or a change in the direction of gaze to view through optical zones of different optical powers (bifocal, trifocal or progressive addition spectacle lenses), monovision (with contact lenses, intraocular lenses, laser refractive surgery and corneal collagen shrinkage), simultaneous images (with contact lenses, intraocular lenses and corneal inlays), pinhole depth of focus expansion (with intraocular lenses, corneal inlays and pharmaceuticals), crystalline lens softening (with lasers or pharmaceuticals) or restored dynamics (with 'accommodating' intraocular lenses, scleral expansion techniques and ciliary muscle electrostimulation); these strategies may be applied differently to the two eyes to optimise the range of clear focus for an individual's task requirements and minimise adverse visual effects. However, none fully overcome presbyopia in all patients. While the restoration of natural accommodation or an equivalent remains elusive, guidance is given on presbyopic correction evaluation techniques.

Safety and satisfaction of myopic small-incision lenticule extraction combined with monovision

Background

To investigate the safety and optical quality of small-incision lenticule extraction (SMILE) combined with monovision, and patient satisfaction with the procedure.

Methods

The present study assessed a non-random case series involving 60 eyes of 30 patients (mean age 45.53 ± 3.20 years [range 41 to 52 years]) treated bilaterally using the VisuMax 500 system (Carl Zeiss Meditec, Jena, Germany) between January and July 2016. The target refraction was plano for the distance eye, and between − 0.5 and − 1.75 diopters (D) for the near eye. Visual acuity, refraction errors, ocular aberrations, and satisfaction questionnaire scores were calculated 1 year after surgery.

Results

All surgeries were uneventful, with a mean safety index of 1.03 and 1.04 in dominant and nondominant eyes, respectively. Binocular uncorrected distance visual acuity of all patients was ≥20/32, while binocular uncorrected near visual acuity was ≥20/40 1 year postoperatively. Higher-order aberration (0.45 ± 0.14, 0.51 ± 0.15 μm), spherical (0.18 ± 0.15, 0.21 ± 0.14 μm) and coma aberration (0.31 ± 0.16, 0.27 ± 0.17 μm) were identical between dominant and nondominant eyes after surgery. The overall satisfaction rate was 86.7% (26/30), with large contributions from age (OR = 1.76 95% CI: 1.03–2.53; P = 0.036). Binocular uncorrected distance visual acuity was related to preoperative spherical diopter (r = − 0.500; P = 0.005).

Conclusions

Monovision appears to be a safe and effective option for myopia patients with presbyopia who are considering the SMILE procedure. Patients with younger age were more satisfied with the procedure.

Light disturbance with multifocal contact lens and monovision for presbyopia

Dysphotopsia affects a significant number of patients, particularly after visual correction with multifocal optical designs.

PURPOSE

Evaluate light distortion (LD) in two modalities of contact lens (CL) wear: multifocal (MF) and monofocal (MV).

METHODS

This was a randomized, double-masked, crossover study involving 20 presbyopic patients. Patients were randomized first into either MF or MV for 15 days of use with a 1 week wash-out period between each lens type. The LD was evaluated with the Light Distortion Analyzer (LDA, University of Minho) under monocular and binocular conditions. The light distortion index (LDI, %), among other parameters were analyzed. Subjective quality of vision was assessed with the Quality of Vision (QoV).

RESULTS

The LD showed an increase in all parameters in both CL modalities being significant for MV in the non-dominant eye (p < 0.030, for all LD parameters). For the MF, there was also a significant increase in LDI (p = 0.016) and in BFCrad (p = 0.022) in the non-dominant eye. After 15 days of MF lens wear, there was a significant decrease in all LD parameters (p < 0.002) in the dominant eye. Binocularly, a significant improvement from 1 to 15 days was observed for LDI (p = 0.009) and BFCrad (p = 0.0013) with MF. The QoV questionnaire showed no significant changes with neither CL.

CONCLUSIONS

Adaptation to light disturbances induced by MF CL is more effective compared to MV. Practitioners will have greater success if they prepare their patients for the adaptation required as their vision will get better and have less of an issue with light disturbance.

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.

Ocular Straylight with Different Multifocal Contact Lenses

PURPOSE

Multifocal contact lenses have been growing in popularity as a modality to correct presbyopic eyes, although visual side effects such as disability glare have been reported. The objective of this study was to investigate the effect of multifocal contact lenses on disability glare by means of ocular straylight.

METHODS

A prospective randomized, comparative study was performed that included 16 subjects free of ocular pathology. Straylight was measured using a commercial straylight meter with the natural and dilated pupil. Participants were fitted with Proclear Multifocal (Distance/Near), ACUVUE Oasys for Presbyopia, and Air Optix Aqua Multifocal randomized to the left or right eye. Straylight measurements were repeated with the contact lens in situ after the pupil dilation. Results obtained with the dilated pupil without contact lens acted as a control.

RESULTS

Diameter of the natural and dilated pupil was 2.87 ± 0.40 mm and 7.45 ± 0.86 mm, respectively (P < .001). After pupil dilation, straylight increased from 0.92 ± 0.13 log(s) to 1.04 ± 0.11 log(s) (P < .001). Of the four studied lenses, a significant difference was only found between Air Optix and the control group (P = .006). The latter showed also slightly increased light scatter.

CONCLUSIONS

A difference in measured straylight was found between the studied multifocal lenses. The observed variability and the straylight-pupil size dependency should be taken into account to avoid elevated straylight in multifocal contact lens wearers. The reason for the observed differences in straylight must be the subject of future studies.

Soft multifocal simultaneous image contact lenses: a review

Soft multifocal simultaneous image contact lenses have boomed in recent years due to the growing number of presbyopic patients demanding visual solutions, allowing them to maintain their current standard of living. The concept of 'simultaneous image' is based on blur interpretation and/or blur tolerance of superimposed multiple images on the retina formed by various powers of a contact lens. This is the basis for a specific type of multifocal contact lens developed for the compensation of presbyopia. Manufacturers have released a great variety of soft simultaneous image lens designs to meet different patient needs but their fitting is still unsatisfactory in some cases. Some presbyopes discontinue wearing contact lenses due to some limitations in visual quality and comfort that can be overcome with an appropriate contact lens selection based on a comprehensive pre-fitting evaluation. This paper aims to review the different types of soft multifocal contact lenses that are currently available for presbyopic correction and to define the steps and factors crucial for their fitting, such as pupil, aberrations, accommodation and centring. A discussion about useful tools to achieve a customised fitting leading to a successful outcome, such as the defocus curve, power profile and questionnaires, is performed.

Glaucoma and Driving: On-Road Driving Characteristics

Purpose

To comprehensively investigate the types of driving errors and locations that are most problematic for older drivers with glaucoma compared to those without glaucoma using a standardized on-road assessment.

Methods

Participants included 75 drivers with glaucoma (mean = 73.2±6.0 years) with mild to moderate field loss (better-eye MD = -1.21 dB; worse-eye MD = -7.75 dB) and 70 age-matched controls without glaucoma (mean = 72.6 ± 5.0 years). On-road driving performance was assessed in a dual-brake vehicle by an occupational therapist using a standardized scoring system which assessed the types of driving errors and the locations where they were made and the number of critical errors that required an instructor intervention. Driving safety was rated on a 10-point scale. Self-reported driving ability and difficulties were recorded using the Driving Habits Questionnaire.

Results

Drivers with glaucoma were rated as significantly less safe, made more driving errors, and had almost double the rate of critical errors than those without glaucoma. Driving errors involved lane positioning and planning/approach, and were significantly more likely to occur at traffic lights and yield/give-way intersections. There were few between group differences in self-reported driving ability.

Conclusions

Older drivers with glaucoma with even mild to moderate field loss exhibit impairments in driving ability, particularly during complex driving situations that involve tactical problems with lane-position, planning ahead and observation. These results, together with the fact that these drivers self-report their driving to be relatively good, reinforce the need for evidence-based on-road assessments for evaluating driving fitness.

Randomized Crossover Trial of Silicone Hydrogel Presbyopic Contact Lenses

PURPOSE

To assess the performance of four commercially available silicone hydrogel multifocal monthly contact lens designs against monovision.

METHODS

A double-masked randomized crossover trial of Air Optix Aqua multifocal, PureVision 2 for Presbyopia, Acuvue OASYS for Presbyopia, Biofinity multifocal, and monovision with Biofinity contact lenses was conducted on 35 presbyopes (54.3 ± 6.2 years). After 4 weeks of wear, visual performance was quantified by high- and low-contrast visual acuity under photopic and mesopic conditions, reading speed, defocus curves, stereopsis, halometry, aberrometry, Near Activity Visual Questionnaire rating, and subjective quality of vision scoring. Bulbar, limbal, and palpebral hyperemia and corneal staining were graded to monitor the impact of each contact lens on ocular physiology.

RESULTS

High-contrast photopic visual acuity (p = 0.102), reading speed (F = 1.082, p = 0.368), and aberrometry (F = 0.855, p = 0.493) were not significantly different between presbyopic lens options. Defocus curve profiles (p < 0.001), stereopsis (p < 0.001), halometry (F = 4.101, p = 0.004), Near Activity Visual Questionnaire (F = 3.730, p = 0.007), quality of vision (p = 0.002), bulbar hyperemia (p = 0.020), and palpebral hyperemia (p = 0.012) differed significantly between lens types, with the Biofinity multifocal lens design principal (center-distance lens was fitted to the dominant eye and a center-near lens to the nondominant eye) typically outperforming the other lenses.

CONCLUSIONS

Although ocular aberration variation between individuals largely masks the differences in optics between current multifocal contact lens designs, certain design strategies can outperform monovision, even in early presbyopes.

Pupil diameter, working distance and illumination during habitual tasks. Implications for simultaneous vision contact lenses for presbyopia

PURPOSE

To determine working distance, pupil diameter and illumination in real life conditions in a sample of presbyopic participants performing habitual tasks.

METHODS

A total of 59 presbyopic subjects (aged between 45 and 63 years) with different occupational backgrounds participated in the study. Participants were first interviewed regarding their habitual tasks with the aid of an ad hoc questionnaire, following which in-office photopic and mesopic pupil diameter was determined. Pupil diameter was also evaluated while participants conducted each of the self-reported habitual tasks by taking a photograph, which was later submitted to image analysis. In addition, working distance was determined with a measuring tape and the illumination that reached the pupil during each of the different tasks was measured, in lux, with a light meter.

RESULTS

The four most common habitual tasks were computer use, reading, sewing and sports. A high intersubject variability was found in pupil diameter, working distance and illumination conditions while conducting the same task. Statistically significant differences were found between the in-office measured photopic and mesopic pupil diameters and those obtained while participants were conducting their habitual tasks in real life conditions (all p<0.001).

CONCLUSIONS

Potential multifocal contact lens users may present with different ages, different jobs or hobbies and different preferences regarding lighting conditions and working distances. This results in different pupil size, even within the same task. This information may be critical when selecting a particular lens design and add power. Eye care practitioners are therefore advised to assess pupil diameter in real life conditions.

Aged Drivers May Experience Decreased Visual Function While Driving

PURPOSE

To investigate conventional visual acuity (VA) and changes therein over time in older drivers.

DESIGN

A cross-sectional study.

METHODS

One hundred twenty-four drivers (41 younger drivers aged 21-39 years, 40 middle-aged drivers aged 40-59 years, and 43 older drivers aged 60-77 years) who consented to undergo conventional and functional VA testing, perform the Trail Making Test B, and complete a questionnaire on visual performance while driving at an expressway rest stop in Ashigara, Japan, were studied.

RESULTS

The overall proportion of the study subjects with a decimal bilateral VA less than 0.7, the Japanese threshold score for obtaining and renewing a driver's license, was 10%. The number of the subjects with decimal functional VA scores and minimum VA scores less than 0.7 was significantly higher in the older group than in the younger group (P < 0.05), although the conventional VA scores did not differ significantly between the older and younger groups (P = 0.621). The Trail Making Test B scores were significantly higher in the older group than in the younger and middle-aged groups (P < 0.05). The total score of the "visual performance during driving at night" category correlated significantly with the logMAR functional VA and logMAR minimum VA (P < 0.05) but not the logMAR VA.

CONCLUSIONS

Older drivers might experience decreased functional VA and increased frequency of transient decreases in VA while driving. The functional VA test might capture visual impairment among older drivers that went undetected by the conventional VA test.

Adaptation to multifocal and monovision contact lens correction

PURPOSE

To compare visual performance with the Biofinity multifocal (MF) contact lens with monovision (MV) with the Biofinity single-vision contact lens.

METHODS

A crossover study of 20 presbyopic patients was conducted. Patients were randomized first into either an MF or an MV lens for 15 days for each modality, with a washout period between each lens type. Measurements included monocular and binocular high- and low-contrast logarithm of the minimum angle of resolution visual acuity (VA) at distance and near visions, binocular distance contrast sensitivity function, and near stereoacuity.

RESULTS

At 15 days, patients lost fewer than two letters (half a line of VA) of binocular distance and near VA, with the MF and MV lens under high- and low-contrast conditions (P > 0.05 for both comparisons). No statistically significant differences were seen in binocular VA at near or distance with either lens. However, the monocular distance VA improved significantly in the nondominant eye, with the MF lens by one line over the 15-day period under high-contrast (P = 0.023) and low-contrast (P = 0.035) conditions; this effect was not seen with the MV lens. Contrast sensitivity function was within the normal limits with both lenses. The stereoacuity was significantly (P < 0.01) better with MF than with MV.

CONCLUSIONS

Multifocal contact lens correction provided satisfactory levels of VA comparable with MV without compromising stereoacuity in this crossover study. The near vision significantly improved in the dominant eye, and the distance vision improved in the nondominant eye from 1 to 15 days with the MF lens, suggesting that patients adapted to the multifocality overtime, whereas this was not true for MV.

Quantification of ghosting produced with presbyopic contact lens correction

OBJECTIVES

The defocused portion of the image obtained in wearers of bifocal and multifocal contact lenses often appears as a "ghost." Relatively few methods exist to quantify the ghosting perceived with lenses. The purpose of this study is to validate and implement a questionnaire to help patients quantify the ghost images perceived with bifocal or multifocal corrections.

METHODS

Ten subjects viewed simulated bifocal vision images displayed on a monitor. Images contained a focused and a defocused (ghost) component of a specific dimension (direction, position offset, intensity, and focus). Using a test card, the subjects identified the ghosting dimension level displayed on the monitor. An additional 54 presbyopic subjects wearing a multifocal correction monocularly viewed a well-focused stimulus and then compared the perceived image to that of the other well-corrected eye looking at the ghosting test card to quantify their visual experience of the 4 proposed ghosting dimensions.

RESULTS

Regardless of ghost letter size and orientation, subject responses were within 1 rating unit of expected on >95% of all trials for all 4 dimensions when asked to directly match a single dimension of ghosting. With bifocal images containing random amounts of these 4 dimensions most response errors were also within ± 1 unit. In presbyopes wearing a multifocal lens, the focus dimension was most strongly associated with overall ratings of ghosting.

CONCLUSIONS

The subjects can accurately and reliably report on ghost intensity, focus, direction and position offset, and well-focused ghosts are most correlated with the overall perceptual saliency of ghosting.

Task oriented visual satisfaction and wearing success with two different simultaneous vision multifocal soft contact lenses

Purpose

A longitudinal prospective, cross-over, double masked study was designed to evaluate task oriented visual satisfaction and wearing success with two types of simultaneous vision multifocal soft contact lenses.

Methods

Twenty-two presbyopic subjects followed two 14-day trial periods in which they were alternatively and randomly fitted with two types of multifocal lenses. Habitual tasks were described in terms of observation distance, visual demand level and time allocation. Subjects graded visual satisfaction with each pair of lenses and each habitual task at different times during each trial. Overall satisfaction was evaluated after completion of the two trial periods. Wearing success was determined by the percentage of subjects opting to continue multifocal lens wear and by the number of subjects still wearing their lenses six months later.

Results

Viewing distance and visual demand level were found to influence visual satisfaction (p < 0.001). Visual satisfaction decreased for tasks involving higher visual demands and for near and far viewing distances, rather than for intermediate vision or a combination of near and far vision. A combined effect of lens type and evaluation time was discovered (p = 0.046). Although 78% of subjects decided to continue lens wear, only one subject was wearing them on a daily basis 6 months after the completion of the study. Insufficient quality of vision was reported as the main reason for multifocal contact lens discontinuation.

Conclusions

A task oriented visual satisfaction evaluation may prove helpful in lens design selection, as well as in predicting wearing success.

Visual outcomes of LASIK-induced monovision in myopic patients with presbyopia

PURPOSE

To evaluate binocular visual acuity (VA), contrast sensitivity, and stereopsis in myopic patients after laser in situ keratomileusis (LASIK)-induced monovision.

DESIGN

Prospective, observational study.

METHODS

We performed a prospective study of 37 consecutive patients older than 45 years who underwent bilateral myopic LASIK with planned monovision. At the 6-month postoperative visit, we evaluated distance and near binocular visual acuity, contrast sensitivity, and stereopsis. Binocular tests were done without spectacles (in monovision condition) and compared with the results obtained by repeating the same binocular tests with the same patients (serving as a control group) after spectacle correction of the residual myopic defect in the nondominant eye for distance tests (reverting monovision) and after spectacle correction of the presbyopia bilaterally for near tests (near best spectacle-corrected VA).

RESULTS

By inducing a mean residual spherical equivalent defect of -0.97 diopter in the nondominant eye, the patients achieved a mean near binocular uncorrected visual acuity (UCVA) of 0.74, a mean reading test binocular UCVA of 0.88 using an acceptable spontaneous reading distance (48 cm), and a mean distance binocular UCVA of 1.08. A slight decrease in contrast sensitivity and stereopsis was observed in monovision compared to full distance correction.

CONCLUSIONS

Monovision is a valid option for myopic patients with presbyopia who are considering LASIK. Good distance and near UCVAs can be obtained with this procedure.