Trifocal intraocular lenses versus bifocal intraocular lenses after cataract extraction among participants with presbyopia

BACKGROUND

Presbyopia occurs when the lens of the eyes loses its elasticity leading to loss of accommodation. The lens may also progress to develop cataract, affecting visual acuity and contrast sensitivity. One option of care for individuals with presbyopia and cataract is the use of multifocal or extended depth of focus intraocular lens (IOL) after cataract surgery. Although trifocal and bifocal IOLs are designed to restore three and two focal points respectively, trifocal lens may be preferable because it restores near, intermediate, and far vision, and may also provide a greater range of useful vision and allow for greater spectacle independence in individuals with presbyopia.

OBJECTIVES

To assess the effectiveness and safety of implantation with trifocal versus bifocal IOLs during cataract surgery among participants with presbyopia.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Trials Register) (2019, Issue 9); Ovid MEDLINE; Embase.com; PubMed; ClinicalTrials.gov; and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP). We did not use any date or language restrictions in the electronic search for trials. We last searched the electronic databases on 26 September 2019. We searched the reference lists of the retrieved articles and the abstracts from the Annual Meeting of the Association for Research in Vision and Ophthalmology (ARVO) for the years 2005 to 2015.

SELECTION CRITERIA

We included randomized controlled trials that compared trifocal and bifocal IOLs among participants 30 years or older with presbyopia undergoing cataract surgery.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodology.

MAIN RESULTS

We identified five studies conducted in Europe with a total of 175 participants. All five studies assessed uncorrected distance visual acuity (primary outcome of the review), while some also examined our secondary outcomes including uncorrected near, intermediate, and best-corrected distance visual acuity, as well as contrast sensitivity. Study characteristics All participants had bilateral cataracts with no pre-existing ocular pathologies or ocular surgery. Participants' mean age ranged from 58 to 64 years. Only one study reported on gender of participants, and they were mostly women. We assessed all the included studies as being at unclear risk of bias for most domains. Two studies received financial support from manufacturers of lenses evaluated in this review, and at least one author of another study reported receiving payments for delivering lectures with lens manufacturers. Findings All studies compared trifocal versus bifocal IOL implantation on visual acuity outcomes measured on a LogMAR scale. At one year, trifocal IOL showed no evidence of effect on uncorrected distance visual acuity (mean difference (MD) 0.00, 95% confidence interval (CI) -0.04 to 0.04; I² = 0%; 2 studies, 107 participants; low-certainty evidence) and uncorrected near visual acuity (MD 0.01, 95% CI -0.04 to 0.06; I² = 0%; 2 studies, 107 participants; low-certainty evidence). Trifocal IOL implantation may improve uncorrected intermediate visual acuity at one year (MD -0.16, 95% CI -0.22 to -0.10; I²= 0%; 2 studies, 107 participants; low-certainty evidence), but showed no evidence of effect on best-corrected distance visual acuity at one year (MD 0.00, 95% CI -0.03 to 0.04; I²= 0%; 2 studies, 107 participants; low-certainty evidence). No study reported on contrast sensitivity or quality of life at one-year follow-up. Data from one study at three months suggest that contrast sensitivity did not differ between groups under photopic conditions, but may be worse in the trifocal group in one of the four frequencies under mesopic conditions (MD -0.19, 95% CI -0.33 to -0.05; 1 study; I² = 0%, 25 participants; low-certainty evidence). In two studies, the investigators observed that participants' satisfaction or spectacle independence may be higher in the trifocal group at six months, although another study found no evidence of a difference in participant satisfaction or spectacle independence between groups. Adverse events Adverse events reporting varied among studies. Two studies reported information on adverse events at one year. One study reported that participants showed no intraoperative or postoperative complications, while the other study reported that four eyes (11.4%) in the bifocal and three eyes (7.5%) in the trifocal group developed significant posterior capsular opacification requiring YAG capsulotomy. The certainty of the evidence was low.

AUTHORS' CONCLUSIONS

There is low-certainty of evidence that compared to bifocal IOL, implantation of trifocal IOL may improve uncorrected intermediate visual acuity at one year. However, there is no evidence of a difference between trifocal and bifocal IOL for uncorrected distance visual acuity, uncorrected near visual acuity, and best-corrected visual acuity at one year. Future research should include the comparison of both trifocal IOL and specific bifocal IOLs that correct intermediate visual acuity to evaluate important outcomes such as contrast sensitivity and quality of life.

Phakic intraocular lenses: Recent advances and innovations

Phakic intraocular lenses (pIOL) are recommended when counselling refractive surgery candidates presenting with high ametropia or ocular surface and/or corneal conditions that contraindicate corneal refractive surgery. This review aims to present the state-of-the-art regarding pIOL models currently available in Europe, addressing their newer indications and recent design innovations. These include, in the case of posterior chamber pIOLs, the addition of a central hole to improve aqueous humour circulation, the availability of larger optical zones, and multifocal optics for the compensation of presbyopia. The review also highlights their good safety and efficacy results, as well as the role of patient education to ensure adequate outcomes in the medium-long term. The indications of pIOLs in special situations, as well as bi-lensectomy, a procedure that most pIOL patients may eventually require as they age and develop cataracts, are also addressed.

Rapid Vision Correction by Special Operations Forces

BACKGROUND

This report describes a rapid method of vision correction used by Special Operations Medics in multiple operational engagements.

METHODS

Between 2011 and 2015, Special Operations Medics used an algorithm- driven refraction technique. A standard block of instruction was provided to the medics, along with a packaged kit. The technique was used in multiple operational engagements with host nation military and civilians. Data collected for program evaluation were later analyzed to assess the utility of the technique.

RESULTS

Glasses were distributed to 230 patients with complaints of either decreased distance or near (reading). Most patients (84%) with distance complaints achieved corrected binocular vision of 20/40 or better, and 97% of patients with near-vision complaints achieved corrected near-binocular vision of 20/40 or better. There was no statistically significant difference between the percentages of patients achieving 20/40 when medics used the technique under direct supervision versus independent use.

CONCLUSION

A basic refraction technique using a designed kit allows for meaningful improvement in distance and/or near vision at austere locations. Special Operations Medics can leverage this approach after specific training with minimal time commitment. It can serve as a rapid, effective intervention with multiple applications in diverse operational environments.

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.

The vertical monitor position for presbyopic computer users with progressive lenses: how to reach clear vision and comfortable head posture

When presbyopic employees are wearing general-purpose progressive lenses, they have clear vision only with a lower gaze inclination to the computer monitor, given the head assumes a comfortable inclination. Therefore, in the present intervention field study the monitor position was lowered, also with the aim to reduce musculoskeletal symptoms. A comparison group comprised users of lenses that do not restrict the field of clear vision. The lower monitor positions led the participants to lower their head inclination, which was linearly associated with a significant reduction in musculoskeletal symptoms. However, for progressive lenses a lower head inclination means a lower zone of clear vision, so that clear vision of the complete monitor was not achieved, rather the monitor should have been placed even lower. The procedures of this study may be useful for optimising the individual monitor position depending on the comfortable head and gaze inclination and the vertical zone of clear vision of progressive lenses.

PRACTITIONER SUMMARY

For users of general-purpose progressive lenses, it is suggested that low monitor positions allow for clear vision at the monitor and for a physiologically favourable head inclination. Employees may improve their workplace using a flyer providing ergonomic-optometric information.

The value and underutilization of simple reading glasses in geropsychiatry inpatient settings

For almost everyone, the need for reading glasses is an inevitable part of the second half of life. Forgetting one's reading glasses at a restaurant can be a disturbing reminder of one's dependence on them. For geriatric inpatients, however, the value of reading glasses in improving quality of life and preventing delirium may be overlooked. Subsequently, the authors present a brief review of visual impairment, the relationship of visual impairment and cognition and the cost of reading glass, and the results of a survey that was conducted to determine the proportion of inpatient geriatric psychiatry inpatient units in the United States, which provide reading glasses to inpatients as well as to assess the knowledge of medical directors of these units regarding the cost and perceived value of providing reading glasses to hospitalized patients.

Imaging properties of the light sword optical element used as a contact lens in a presbyopic eye model

The paper analyzes the imaging properties of the light sword optical element (LSOE) applied as a contact lens to the presbyopic human eye. We performed our studies with a human eye model based on the Gullstrand parameterization. In order to quantify the discussion concerning imaging with extended depth of focus, we introduced quantitative parameters characterizing output images of optotypes obtained in numerical simulations. The quality of the images formed by the LSOE were compared with those created by a presbyopic human eye, reading glasses and a quartic inverse axicon. Then we complemented the numerical results by an experiment where a 3D scene was imaged by means of the refractive LSOE correcting an artificial eye based on the Gullstrand model. According to performed simulations and experiments the LSOE exhibits abilities for presbyopia correction in a wide range of functional vision distances.

Strehl ratios characterizing optical elements designed for presbyopia compensation

We present results of numerical analysis of the Strehl ratio characteristics for the light sword optical element (LSOE). For comparison there were analyzed other optical imaging elements proposed for compensation of presbyopia such as the bifocal lens, the trifocal lens, the stenopeic contact lens, and elements with extended depth of focus (EDOF), such as the logarithmic and quartic axicons. The simulations were based on a human eye's model being a simplified version of the Gullstrand model. The results obtained allow to state that the LSOE exhibits much more uniform characteristics of the Strehl ratio comparing with other known hitherto elements and therefore it could be a promising aid to compensate for the insufficient accommodation range of the human eye.

Visual performances with monofocal, accommodating, and multifocal intraocular lenses in patients with unilateral cataract

PURPOSE

To compare the visual performance of patients with unilateral cataract following implantation of monofocal, accommodating, refractive, and diffractive multifocal intraocular lenses (IOL).

DESIGN

Prospective nonrandomized clinical trial.

METHODS

Eighty-seven patients with unilateral cataract were enrolled in 4 groups for phacoemulsification and IOL implantation. Twenty-four patients had monofocal (Alcon Acrysof) (group 1), 21 patients had accommodating (Human Optics 1CU) (group 2), 22 patients had diffractive multifocal (Tecnis ZM900) (group 3), and 20 patients had refractive multifocal (AMO Rezoom) (group 4) IOL implantations. Ages of patients were between 40 and 70. Parameters analyzed at the 18th postoperative month were subjective refractions, monocular and binocular distance, intermediate and near uncorrected visual acuities, monocular distance and near best-corrected visual acuities, monocular distance-corrected intermediate and near visual acuities, stereopsis, visual complaints, and spectacle dependency.

RESULTS

No significant difference was observed between distance and near best-corrected visual acuities of IOL groups, and between intermediate visual acuities of groups 2, 3, and 4. Groups 3 and 4 had statistically better near vision than the other groups (P < .05). No significant difference was observed between near visual acuities of groups 3 and 4. Number of patients with better stereoscopic function, spectacle independence, and complaints of halo in groups 3 and 4 was significantly higher than in other groups (P < .05).

CONCLUSIONS

Multifocal IOLs provide better stereopsis, higher spectacle independence rates, and satisfactory functional vision over a broad range of distances in presbyopic patients with unilateral cataract compared with the monofocal and accommodating IOLs.

Extended depth of focus contact lenses for presbyopia

The purpose of this Letter is to design, develop, fabricate, and test in clinical trials a new (to our knowledge) type of contact lenses that provides simultaneous near and distance focused vision for presbyopic subjects, including those with up to 2.00 diopters (D) of regular/irregular astigmatism, as an alternative to multifocal contact lenses. The purpose is obtained by generating an optical pattern on the front surface of contact lenses, capable of extending the depth of focus of lenses by 3.00 D with high visual contrast. The pattern was fabricated on top of contact lenses and tested by the use of an eye simulation as well as in clinical trials. Use of the extended depth of focus contact lens enabled patients to achieve good visual acuity and contrast sensitivity for both distance and near vision without compromising the energy distribution or the visual fields.

Preventing falls in older multifocal glasses wearers by providing single-lens distance glasses: the protocol for the VISIBLE randomised controlled trial

BACKGROUND

Recent research has shown that wearing multifocal glasses increases the risk of trips and falls in older people. The aim of this study is to determine whether the provision of single-lens distance glasses to older multifocal glasses wearers, with recommendations for wearing them for walking and outdoor activities, can prevent falls. We will also measure the effect of the intervention on health status, lifestyle activities and fear of falling, as well as the extent of adherence to the program.

METHODS/DESIGN

Approximately 580 older people who are regular wearers of multifocal glasses people will be recruited. Participants will be randomly allocated to either an intervention group (provision of single lens glasses, with counselling and advice about appropriate use) or a control group (usual care). The primary outcome measure will be falls (measured with 13 monthly calendars). Secondary measures will be quality of life, falls efficacy, physical activity levels and adverse events.

DISCUSSIONS

The study will determine the impact of providing single-lens glasses, with advice about appropriate use, on preventing falls in older regular wearers of multifocal glasses. This pragmatic intervention, if found to be effective, will guide practitioners with regard to recommending appropriate glasses for minimising the risk of falls in older people.

TRIAL REGISTRATION

The protocol for this study was registered with the Clinical Trials.gov Protocol Registration System on June 7th 2006 (#350855).

An exploration of modified monovision with diffractive bifocal contact lenses

A group of eight presbyopic subjects wore in succession four types of correction. One of these (A) consisted of a conventional pair of diffractive bifocals in which equal amounts of light contributed to the distance and near images in both eyes. Two (B and C) were modified monovision corrections using non-standard diffractive bifocal lenses. The diffractive designs were such that in the dominant eye a greater fraction of light was sent into the distance image and less into the near image and in the non-dominant eye a greater fraction contributed to the near image. The last lens combination (D) was a conventional monovision arrangement, with a single-vision distance correction on the dominant eye and a single-vision near correction on the non-dominant eye. Monocular and binocular high-contrast acuity, contrast sensitivity and stereopsis were assessed at both distance and near with each of the four lens combinations. It was hoped that the modified monovision arrangements (B and C) might yield improved distance and near acuities in comparison with the standard diffractive bifocals (A) while still maintaining good stereopsis in comparison with the single-vision monovision combination (D) and thus allow wearers to achieve better all round visual performance. Although these expectations were at least partly fulfilled, the modest advantages offered by the diffractive modified monovision approach did not appear to compensate for the disadvantages of its greater complexity.

LASIK in the presbyopic age group: safety, efficacy, and predictability in 40- to 69-year-old patients

OBJECTIVE

To report the safety, efficacy, and predictability of LASIK in a presbyopic population and to examine possible differences between age groups.

DESIGN

Retrospective, descriptive, comparative consecutive case series.

PARTICIPANTS

Seven hundred ten eyes of 424 patients between 40 and 69 years of age who underwent LASIK by the same surgeon between January 1999 and September 2005. Patients had manifest refractive spherical errors ranging from -10.5 to +6 diopters (D) and cylinder of up to 2.50 D.

METHODS

LASIK was performed with IntraLase femtosecond laser or Hansatome microkeratomes and VISX Star (S4 or S2; VISX Inc., Santa Clara, CA) or Baush & Lomb Technolas 217z (Zyoptix or PlanoScan; Bausch & Lomb, Claremont, CA) excimer lasers. There were 511 myopic eyes (spherical equivalent [SE], -5.03+/-2.02 D) and 199 hyperopic eyes (SE, +2.21+/-1.21 D). Patients were divided into 3 groups: group 1 (40 to 49 years old; n = 359 eyes), group 2 (50 to 59 years old; n = 293 eyes), and group 3 (60 to 69 years old; n = 58 eyes).

MAIN OUTCOME MEASURES

Uncorrected visual acuity (UCVA) and best spectacle-corrected visual acuity (BSCVA), retreatment rates, safety, efficacy, and predictability.

RESULTS

The mean age of patients in groups 1, 2, and 3 was 45, 53, and 63 years, respectively. With increasing age, there was a trend toward higher retreatment rates and more myopic end points. Safety, efficacy, and predictability were comparable between all groups. At the final follow-up (mean+/-standard deviation, 10.4+/-7.4 months), 80% to 100% of eyes had 20/30 or better UCVA and 81% to 90% were within +/-1.00 D. No eyes lost more than 2 lines of BSCVA, and only 9 eyes (1.3%) lost 2 lines. Subgroup analysis of eyes with a follow-up of 12 months or more was performed. The results were compared with those with shorter follow-up. Both subgroups had comparable outcomes; the duration of follow-up did not affect the visual outcomes.

CONCLUSIONS

Despite a trend toward worse final BSCVA and higher retreatment rates in older patients, a greater risk of visual loss after LASIK was not observed. LASIK for myopia and hyperopia has reasonable safety, efficacy, and predictability profiles in the 40- to 69-year-old presbyopic population.

Computer-based primary visual cortex training for treatment of low myopia and early presbyopia

PURPOSE

The NeuroVision technology is a noninvasive, patient-specific, perceptual learning program based on visual stimulation and facilitation of neural connections at the cortical level, involving a computerized visual training regimen using Gabor patches, to improve contrast sensitivity and visual acuity. The efficacy of NeuroVision in enhancing uncorrected visual acuity (UCVA) and unaided contrast sensitivity function (CSF) in patients with low myopia or early presbyopia was evaluated.

METHODS

Seventeen patients with low myopia (up to -1.75 D) and 21 patients with early presbyopia (up to +2.50 D add) were recruited in 2 clinical sites. Eleven myopic and 18 presbyopic patients underwent the NeuroVision program (treatment group), and 9 patients performed visual examinations only, serving as a control group.

RESULTS

The low myopia treatment group achieved a mean improvement of 2.2 logMAR lines in unaided VA, from 0.42 to 0.20 logMAR. Unaided CSF improved at all spatial frequencies (1.5, 3, 6, 12, 18 cpd). The early presbyopia treatment group achieved a mean improvement of 2.2 logMAR lines in near UCVA, from 0.47 to 0.25 logMAR. Near unaided CSF also improved at all spatial frequencies. The control patients in both arms of the study have not shown any significant change in vision. Additionally, the mean refractive error in all groups remained unchanged after treatment.

CONCLUSIONS

Results to date suggest that the NeuroVision technology is effective in improving UCVA and unaided CSF in low myopia and early presbyopia.

The Impact of Assistive Device Use on Disability and Depression Among Older Adults With Age-Related Vision Impairments

OBJECTIVE

One can conceptualize adaptive technology as a resource used by disabled older adults in order to maintain competence in everyday life. This study examined the independent relationships between optical and adaptive device utilization and change in functional disability and depression among older adults with age-related vision impairments.

METHODS

We interviewed older adults (n = 438) with a recent vision impairment applying for vision rehabilitation services both pre-service and at the 6-month follow-up. We conducted hierarchical regression analyses with functional disability and depressive symptoms as criteria. In order to identify their independent direct effects, we entered optical and adaptive device use into the final step, preceded by Time 1 criterion scores, demographics, baseline disability or depression (depending on criterion), and total rehabilitation service hours.

RESULT

Optical, but not adaptive, device use was significantly associated with declines in functional disability and depressive symptoms over time.

DISCUSSION

We propose that these differential effects result from the fact that optical devices optimize residual vision and thus allow for greater continuity in the way tasks are accomplished (i.e., reading still performed visually), whereas use of adaptive aids (e.g., talking books) involves learning new methods in order to compensate for lost functions and thus is not as desirable either functionally or psychologically.

Presbyopiekorrektur mittels Intraokularlinsen

Modern cataract surgery has advanced tremendously over the past 20 years. Improved surgical techniques, as well as improved implant materials and designs, have enlarged patient profiles and indications not only for cataract surgery, but also for refractive lens exchange surgery. This has also created much higher patient expectations. The loss of accommodation is a loss of quality of life for presbyopic and especially young pseudophakic patients. Multifocal intraocular lenses (MIOL) have been implanted since 1986, starting with 2-3 zone refractive and diffractive designs. Due to the surgical techniques available at that time, MIOL decentration and surgically induced astigmatism were possible complications. In addition, reduced contrast perception and increased glare were common problems of MIOL because of their optical principles. New developments in this field in recent years such as the folding, multizonal, progressive refractive MIOL and aspheric diffractive MIOL in combination with improved surgical techniques have overcome those initial problems. Therefore, modern MIOL (and in the future also accommodative IOL) can be considered not only for the correction of aphakia but also for refractive purposes.

Ausgleich der Presbyopie mit Kontaktlinsen

Contact lens fitting for presbyotic patients needs more than simple fitting shill; patients need additional psychological support. The wearer has to accept optical quality reduction due to the multifocality of the lens design. In general, the technical fitting of presbyotic contact lenses is comparable to monofocal systems. They work with the same rules of performance. The difference lies in the principles of correction by the lens itself. Simple presbyotic systems use uncorrected optical aberration to widen depth perception. These lenses are suitable for young presbyopes, up to a need of 1 diopter plus power for near vision. Uncorrected aspherical designs have a multifocal effect which can be used for presbyotic lenses. There are contact lenses on the market with simultaneous imaging, which is based on concentric rings around the near or distance centre. Another principles are based on segmented reading portions in the lower part of the lens, also called alternating systems. These very few design variations are the basis for the various specific models which are sold on the market today. The results of the fitting can never be foreseen as subjective and psychological aspects of the wearer overlay the objective results. Thus, the fitter needs experience and patient understanding, combined with fundamental knowledge of the specific lens type used.

Optical surface optimization for the correction of presbyopia

Presbyopia, the gradual loss of accommodation that accompanies aging, can be corrected by creating asphericity in the optical path of the eye. Bifocal and aspheric contact lenses, intraocular lenses, spectacle lenses, and laser refractive surgery are all widely used to alleviate the symptoms of presbyopia. These types of corrective surfaces try to concentrate vision in limited peaks over the full range of vergences. The methodology described in this paper is designed to correct presbyopia by optimizing vision over the entire target range of near to distant. A corrective surface was created by employing an iterative function minimization algorithm to optimize an optical metric. In most cases, it is possible to obtain an optical surface that will optically compensate for presbyopia.

Visual performance of a multi-zone bifocal and a progressive multifocal contact lens

PURPOSE

This study measured the relative visual performance of two planned-replacement soft contact lenses for presbyopic correction: a multi-zone bifocal (ACUVUE, Johnson & Johnson Vision Care, Jacksonville, FL) contact lens and a progressive multifocal (Focus Progressives, CIBA Vision, Duluth, GA) contact lens.

METHODS

This was a randomized, double-masked, non-dispensing cross-over study. Visual performance was evaluated by log of minimal angle of resolution (LogMAR) measurement of visual acuity (VA) under a representative range of luminances (distance 250 candela[cd]/m2 and 2.5 cd/m2, near 250 cd/m2 and 50 cd/m2) and contrasts (90% and 10%). The 45 presbyopic subjects were equally distributed in three subgroups according to spectacle addition: low presbyopia (+0.75D to +1.25D); medium presbyopia (+ 1.50D to + 1.75D); and high presbyopia (+2.00 to +2.50D).

RESULTS

Statistically significant differences were found in overall distance VA (P<0.001; average of four luminance-contrast combinations) and low-luminance distance VA (P=0.004), which, in both cases, favored the multi-zone bifocal lens design. For low presbyopes, the multi-zone bifocal design produced a significantly better visual performance (P=0.004) than did the progressive multifocal. Overall near VA was also significantly better (P<0.001) with the multi-zone bifocal lens. Differences in near VA were particularly marked in high-luminance conditions (high and low contrasts combined) and were statistically significant for all three presbyopic subgroups.

CONCLUSIONS

Visual acuity performance with the multi-zone bifocal was superior overall to that achieved with the progressive multifocal design. This study suggests that having only one addition is detrimental to performance with the progressive multifocal lens, particularly for low presbyopes.

Factors influencing success of monovision contact lens fitting: survey of contact lens diplomates

BACKGROUND

Contact lenses are frequently fitted so that one eye is focused for distance and the other for near (monovision) in order to reduce the dependence of presbyopic patients on bifocal spectacle correction.

METHODS

We surveyed Diplomates in the Cornea and Contact Lens section of the American Academy of Optometry (N = 179) regarding their estimates of success with monovision fitting and factors influencing their perception of success. Results were statistically analyzed to determine the fitting philosophies of responders estimating that they achieve high success rates (HSRs) and low success rates (LSRs), respectively.

RESULTS

Completed surveys were returned by 98 Diplomates (54.8%), who estimated an overall success rate of approximately 71.7% with monovision; 50.5% "totally successful" (wear monovision correction full-time without problems or need for additional correction) and 21.2% "successful" (wear monovision full-time, but experience some symptoms of blur or other discomfort, may wear over-correction at times for driving or detailed near work). Sighting dominance was the most frequently used method to determine the distant eye, followed by the plus-lens test. The HSR group tended to be more likely to take occupational factors into account when deciding which eye to use for the distance lens, and they used more flexibility in determining the near-add power. The LSR group discontinued monovision sooner than the HSR group, who continued treatment for longer than 4 weeks during the adaptation period much more often for all add ranges.

CONCLUSIONS

Practitioners who regard monovision treatment as very successful have somewhat different fitting philosophies than those who regard monovision as unsuccessful. Implementation of highly successful practitioners' fitting techniques may increase success with monovision contact lens fitting.

Evaluation of the ZEBRA 2000 (Z-10) Breger Vision bifocal contact lens

PURPOSE

Evaluate the ZEBRA 2000 (Z-10) bifocal contact lens on presbyopic and aphakic patients.

METHODS

Thirty-eight patients, 37 presbyopes and one aphake, were fit in the Z-10 and evaluated for 6 months.

RESULTS

Twenty patients (53%) completed 6 months of contact lens wear. Ten (26%) discontinued due to lens related problems, three (8%) discontinued due to other health problems, and five (13%) were lost to follow-up. Average refits per eye were 1.75. Average distance visual acuity was 20/25; average near visual acuity was J1.6; average wear time, 11 hours. Patient satisfaction was rated good in comfort and vision and fair in nighttime glare by patients' subjective evaluation.

CONCLUSIONS

The ZEBRA 2000 (Z-10) can be a useful addition in fitting the general presbyopic patient population.

[Deteriorating vision in the elderly: double stress?]

BACKGROUND

Epidemiologic studies have provided clear evidence that the majority of people affected by severe visual impairment are adults above the age of 60 years. The goal of this psychological research was to analyze the emotional and behavioral consequences of age-related visual impairment in three steps: descriptive data concerned with subjective well-being, depression, everyday competence, and leisure as well as explanations of interindividual variability based on individual and environmental variables are presented (study I). Also, the impact of the time of onset (early versus late in life) is addressed (study II). Finally, the role of the living accomodation (institutional versus private household) was the main target of another study (study III).

MATERIALS AND METHODS

Study I was based on 84 elderly adults who experienced an irreversible visual loss after age 55 years; a control group of unimpaired elderly adults is also included (mean age 75.8, range 59 to 92). In study II, 18 elderly adults who had been blind since their early childhood were compared to nine matched elderly adults who experienced blindness in their later life as well as nine matched unimpaired elderly adults (mean age 71.7, range 63 to 83). The data for study III came from 15 visually impaired institutional residents who were compared to 15 matched unimpaired residents and 15 matched visually impaired and 15 unimpaired older adults living in private households (mean age 87.0, range 78 to 93). All subjects underwent an intensive psychological measurement program.

RESULTS

The findings of study I emphasize that age-related visual impairment is associated with lower subjective well-being, greater depression, reduced everyday competence, and lowered leisure activity level. A significant portion of interindividual variability in these outcomes can be explained by addressing individual variables (e.g., comorbidity) as well as environmental variables (e.g., quality of the dwelling unit). Study II data offer evidence that older adults suffering from blindness since their early childhood are better adapted than older adults who experienced blindness only in their later years. Study III shows that visually impaired institutional residents reveal deficits in everyday competence and social contacts as contrasted with their unimpaired counterparts, whereas no difference is observed in the domain of subjective well-being.

CONCLUSIONS

All three studies point to the negative impact of age-related visual impairment on emotional and behavioral adaptation in later life. This highlights the need for a whole range of rehabilitative efforts, including psychosocial elements, which are described in the final part of this article.

Patients' task-orientation and perceived benefit of amplification in hearing-impaired elderly persons

This study investigated the reported handicap of 50 elderly hearing-impaired patients who were classified as high or low in task-orientation. Measures of perceived handicap were taken when subjects were fitted with hearing aids and three months later. Analysis indicated that subjects classified as both high and low on task-orientation reported significant increases in their hearing impairment at 3 mo., but subjects classified as high on task-orientation reported significantly less handicap than subjects classified as low.

Reduced visual acuity in elderly people: the role of ergonomics and gerontechnology

Gerontology is the scientific study of the ageing process and special problems of aged people. Ergonomics is an applied science for optimizing performance and productivity and reducing the risks of injury, discomfort and illness. Gerontechnology is concerned with fundamental and applied research on the complex interaction of elderly people with technological products and the built environment. It has the potential to improve the capability of people confronted by the challenges of ageing. We suggest that gerontechnology may have a particular role in relation to the reduction of visual acuity, and can improve the comfort and safety of older people.

A quantitative and qualitative assessment of the NOVAWET-Perception bifocal contact lens

PURPOSE

We prospectively evaluated the NOVAWET-Perception multifocal contact lens for comfort and performance.

METHODS

We fit 28 presbyopic patients with this multifocal contact lens. This multifocal rigid gas permeable lens has a multiaspheric back surface and multiple eccentricity values, allowing for a natural field of vision at all angles. Patients were evaluated prior to inclusion in the study and then at 1,3, and 9 months. Evaluations included slit lamp examination, visual acuity, contrast sensitivity, and completion of a questionnaire regarding comfort and overall satisfaction.

RESULTS

At the end of the study, 14 of 28 patients (50%) were successfully wearing the NOVAWET-Perception lenses. Of these, 12 (86%) achieved J2 or better near vision and 13 (93%) achieved 20/25 or better distance vision. Fourteen patients failed to complete the study.

CONCLUSIONS

We believe the NOVALENS multifocal contact lens is a viable option for the correction of many presbyopic patients.

Visual problems of the aging musician

The presbyopic musician presents the ophthalmologist with an often demanding set of visual needs. Many modalities, some necessarily creative, are available to aid older musicians in their vision-dependent art.

Varifocal contact lenses for the correction of presbyopia

A Nissel +1.75 D PS45 lens' label power seems to be made up of about +0.75 D distance and +0.75 D near addition. There are individual variations which will depend on pupil size, corneal shape, lens position and ocular aberrations. When a +0.75 Bausch & Lomb U3 lens was used as a control, there was also a significant increase in 'accommodation' measured (+0.75 D), but this could not be explained. When two other lenses with an aspheric surface were studied, they also showed a near addition effect. In this supplementary study the changes were explained by changes in spectacle accommodation. A lens with two spherical surfaces did not show the expected increase in spectacle accommodation. Astigmatism, as a general rule, was not corrected by the PS45 lens, although the very occasional case did show some reduction. Visual acuity and contrast sensitivity at 8 cpd and 3 cpd were not significantly affected when compared to the control lens.

Broken down by age and sex. The optical correction of presbyopia revisited

New transverse clinical data are presented which describe the time course of presbyopia, as indicated by the temporal change in magnitude of the binocular spectacle add, in normally sighted male and female Caucasian subjects. An initial steep increase in add requirement beginning in the early forties becomes relatively slower but still of significance beyond the mid-fifties. This observation is correlated with the age-related progressive decline in the amplitude of accommodation, itself a consequence of physiological changes in the crystalline lens and capsule. The continuing need for an increase, albeit at a reduced rate, in the positive near supplement beyond the mid-to-late fifties (by which time little or no useful accommodation is available), is now attributed to the visually disruptive effects within the high spatial frequency domain of progressive age-related lenticular changes. The magnification afforded by the positive add increases spatial grain and thereby enhances visibility of detail in an ageing visual system free of any gross senile pathology. A small but consistent gender difference (congruent to 0.1 D) is revealed in presbyopic corrections: physiological and (more probable) physical bases are suggested for the observation that females require an add of greater magnitude than their age-matched male counterparts.

Periodic health examination, 1995 update: 3. Screening for visual problems among elderly patients. Canadian Task Force on the Periodic Health Examination

OBJECTIVE

To provide recommendations to family physicians for screening elderly patients (over 65 years of age) for visual impairment and its common clinical causes.

OPTIONS

Visual acuity screening with Snellen sight chart, funduscopy, retinal photography, tonometry and perimetry.

OUTCOMES

Delay or prevention of visual deterioration or blindness.

EVIDENCE

A MEDLINE search for relevant articles published between January 1986 and December 1993 was undertaken, the bibliographies of the articles were scrutinized for additional articles, and experts were consulted. The highest available level of evidence was used in making recommendations.

VALUES

The evidence-based methods and values of the Canadian Task Force on the Periodic Health Examination were used. Preservation of vision was given the highest value in accordance with other guidelines regarding eyesight.

BENEFITS, HARMS AND COSTS

Potential benefits are to maintain or improve visual acuity. Potential for harm to patients is minimal. Limited data are available on costs.

RECOMMENDATIONS

There is fair evidence to include in the periodic health examination visual acuity testing with a Snellen sight chart and funduscopy or retinal photography in elderly patients with diabetes of at least 5 years' duration (grade B recommendation). The place of funduscopy in the detection of age-related macular degeneration and glaucomatous changes is controversial. For patients at high risk for glaucoma (positive family history, black race, severe myopia or diabetes) it would be prudent to have a periodic assessment by an ophthalmologist.

VALIDATION

Recommendations differ from those of the American Academy of Ophthalmology and the American Optometric Association. Recommendations for glaucoma screening are similar to those of the US Preventive Services Task Force. Present recommendations have been reviewed by experts in ophthalmology and optometry.

SPONSOR

These guidelines were developed and endorsed by the task force, which is funded by Health Canada and the National Health Research and Development Program. The principal author (C.P.) was supported in part by the Educational Centre for Aging and Health, McMaster University, Hamilton, Ont.

New range of stand magnifiers based on standardized image position

Combined Optical Industries Ltd. of Slough, UK, have released a new range of illuminated stand magnifiers. These have been designed with a uniform emerging vergence and are specified in terms of equivalent power according to the new standards. This paper describes these magnifiers in terms of their measured optical and ergonomic properties. The expected enlargement ratios achieved with typical presbyopic additions are tabulated.

Direction of gaze and comfort: discovering the relation for the ergonomic optimization of visual tasks

Perceived exertion caused by the extraocular muscles was assessed as a function of the direction of gaze and recorded in 114 subjects using a psychometric method. The results confirm statements in the literature that maximum comfort is achieved when gaze is aimed downwards. We found no correlations between perceived exertion and age or viewing distance. The relationship is relevant to ergonomics, for example in lens fitting and workplace layout.

[Presbytia: are eyeglasses unavoidable?]

The power of eye accommodation to close vision decreases with age. This physiological process, called presbytia (or presbyopia), occurs in all people reaching maturity, irrespective of sex and race. This paper describes the evolution of our knowledge concerning this phenomenon and the various means of correction utilized nowadays to compensate for the loss of accommodation power.

Computer-specific spectacle lens design preference of presbyopic operators

Twenty-nine presbyopic subjects who spent at least 20 hours a week at a video display terminal compared a progressive addition lens designed for this function, with another commonly prescribed task-specific lens. Each of the paired lens types was worn for 4 weeks and then compared directly for 1 week. A statistically significant (P < .05) portion of the subjects (76%) preferred the task-specific lenses overall. It also was preferred more frequently for each feature compared, although the difference was statistically significant (P < .05) only for utility of distance vision. Both of the task-specific designs contributed to symptomatic relief. The presence of a distance-clear zone and the absence of lens discontinuities most likely account for user preference for the task-specific lenses. That preference suggests improved performance for presbyopic computer users wearing task-specific progressive addition lenses.

Prescribing spectacles for aviators: USAF experience

This special report was written for USAF vision specialists to use as a guide when prescribing spectacles for military aviators and to extend to the civilian sector the knowledge gained from the USAF experience. Visual correction in aviators presents some unique problems, especially for presbyopes. The demands of each individual aircraft environment need to be well understood. Ophthalmologists and optometrists must consider all pertinent aeromedical factors before prescribing spectacles for ametropic aviators.

Diffractive bifocal contact lenses in aphakia and pseudophakia. A pilot study

Diffractive bifocal contact lenses function by diverting incident light to two focal points. Light from near objects is focused by diffraction while that from distant objects is focused by conventional refraction. Both processes occur simultaneously throughout the full aperture of the lens. Fourteen aphakic and pseudophakic contact lens wearers were fitted with diffractive bifocal lenses and observed for an eight week period. Six (42.8%) were satisfied with the visual result. Five subjects (35.7%) discontinued lens wear complaining of poor quality of near vision. We conclude that these lenses may help selected aphakic patients to discard their reading glasses but the low acceptance rate suggests that this type of optic is probably not suitable for implantation as an intraocular lens.