Presbyopia Research Papers - Academia.edu (original) (raw)

To examine the optical quality of healthy presbyopic eyes before and after implantation of the pseudoaccommodating AcrySof ReSTOR Natural intraocular lens (IOL) (Alcon Laboratories) by measuring visual acuity and wavefront aberrations.University of Valencia, Fernández-Vega Ophthalmological Institute, Valencia, Spain.Monocular refraction and photopic distance (6 m) and near (0.33 m) visual acuities were determined before and after clear lens extraction with bilateral AcrySof ReSTOR Natural IOL implantation in 30 hyperopic eyes (+0.50 to +4.00 diopters [D]) of presbyopic patients with low astigmatism (≤1.00 D). Postsurgical binocular visual acuity was measured over a range of effective distances. Wavefront aberrations were measured before and after surgery. Aberrations for 2 pupil diameters (3.0 mm and 5.0 mm) were decomposed using Zernike polynomials; total, defocus, astigmatism spherical, and coma aberration terms were studied separately. Postimplantation results were compared with preoperative values.Safety and efficacy indices for distance vision were 1.01 and 0.96, respectively. At near, they improved to 1.07 and 1.06, respectively. Vision at intermediate distances was noticeably poorer. Total, defocus, and spherical aberrations changed after IOL implantation with both pupil diameters (P<.01). Total and defocus aberrations were significantly reduced postoperatively. Spherical aberration coefficients changed to negative and less positive values for a 3.0 mm and a 5.0 mm pupil, respectively.Implantation of the pseudoaccommodating IOL in healthy eyes yielded uncorrected levels of high-contrast, distance, and near acuities comparable to preoperative best corrected values. Higher-order aberration levels appeared to be similar to the preoperative values.

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- Ophthalmology, Surgery, Binocular vision, Treatment

This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process which may lead to differences between this version and the Version of... more

- by Helen McAneney
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- Optometry, Medicine, Clinical Sciences, Optometry and Ophthalmology
- by Allon Barsam and +1
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- Neuro ophthalmology, Neuro, Eating, Clinical Sciences

PURPOSE: To examine the effect of uncorrected astigmatism in older adults.

- by Sunil Shah
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- Ophthalmology, Surgery, Binocular vision, Quality of life

Introduction Presbyopia affects people from the 4th decade of life and is characterized by accommodative loss that leads to negative effects on vision-targeted health-related quality of life. A non-invasive pharmacological treatment... more

- by Antonio Renna
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- Ocular Pharmacology, Presbyopia

Background: Presbyopia is an age-related loss of lens accommodation resulting in difficulty in performing near task with attendant effect on the quality of life. Objective: The objective of the study was to determine the prevalence of presbyopia and presbyopic spectacle correction coverage among public school teachers in Ifo township, with a view to providing a baseline information that could be useful for advocacy and planning appropriate intervention. Study Design: The study was a descriptive, cross-sectional study. Materials and Methods: Six hundred public school teachers aged 30 years and above were examined in 25 clusters using a multistage random sampling technique with probability proportional to size. Questionnaire was used to obtain information on demographic data, sources of spectacle and barriers to spectacle use. All participants underwent a standardised protocol including visual acuity assessment (distance and near acuity), anterior and posterior segment examinations and refraction. Results: Six hundred teachers were examined with an age range of 30–61 years. The mean age was 44.7 ± 7.5 years and the male to female ratio was 1:2.2. The prevalence of presbyopia was 81.3% and 38.5% of the presbyopic teachers did not have presbyopic correction. However, the average age of onset of presbyopia was earlier in females 33 years compared to 36 years observed in males, although not statistically significant (P = 0.88). The presbyopic correction coverage was 61.5%. One hundred and eighty-six (62%) presbyopic teachers obtained their spectacle from opticians, and the main barriers to the use of near vision spectacle were lack of awareness (23.7%) and cost (13.7%). Conclusion: This study demonstrated a high prevalence of presbyopia among public school teachers in Ifo town, SouthWest Nigeria, but less presbyopic spectacle correction coverage.

- by Idowu Oluwatobi and +1
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- Presbyopia

Purpose: To compare the performance of a low-addition silicone hydrogel multifocal soft lens with other soft lens correction options in a group of habitual soft lens wearers of distance correction who are symptomatic of early presbyopia. Method: This clinical study was designed as a prospective, doublemasked, randomized, crossover, dispensing trial consisting of four 1-week phases, one for each of the correction modalities: a low-addition silicone hydrogel multifocal soft lens, monovision, habitual correction, and optimized distance visual correction. The prescriptions of all modalities were finalized at a single fitting visit, and the lenses were worn according to a randomized schedule. All lenses were made from lotrafilcon B material. A series of objective vision tests were conducted: high-and low-contrast LogMAR under high-and low-room lighting conditions, stereopsis, and critical print size. A number of other data collection methods used were novel: some data were collected under controlled laboratory-based conditions and others under "real-world" conditions, some of which were completed on a BlackBerry hand-held communication device. Results: All participants were able to be fit with all four correction modalities. Objective vision tests showed no statistical difference between the lens modalities except in the case of low-contrast near LogMAR acuity under low-lighting levels where monovision (ϩ0.29 Ϯ 0.10) performed better than the multifocal (ϩ0.33 Ϯ 0.11, Pϭ0.027) and the habitual (ϩ0.37 Ϯ 0.12, PϽ0.001) modalities. Subjective ratings indicated a statistically better performance provided by the multifocal correction compared with monovision, particularly for the vision associated with driving tasks such as driving during the daytime (93.3 Ϯ 8.8 vs. 84.2 Ϯ 23.7, Pϭ0.05), at nighttime (88.8 Ϯ 11.7 vs. 74.9 Ϯ 23.6, Pϭ0.001), any associated haloes or glare (92.0 Ϯ 10.6 vs. 78.0 Ϯ 22.8, Pϭ0.003), and observing road signs (90.1 Ϯ 11.8 vs. 79.4 Ϯ 20.2, Pϭ0.027). Preference for the multifocal compared with monovision was also reported when watching television (95.0 Ϯ 6.4 vs. 82.6 Ϯ 20.1, Pϭ0.001) and when changing focus from distance to near (87.0 Ϯ 13.4 vs. 66.1 Ϯ 32.2, PϽ0.001). Conclusions: For this group of early presbyopes, the AIR OPTIX AQUA MULTIFOCAL-Low Add provided a successful option for visual correction, which was supported by the results of subjective ratings, many of which were made during or immediately after performing such activities as reading, using a computer, watching television, and driving. These results suggest that making a prediction of "success or not" based on consulting room acuity tests alone is probably unwise.

- by Craig Woods
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- Hydrogels, Visual acuity, Hydrogel, Patient Satisfaction

In healthy persons, the amplitude of ac-commodation (AA) diminishes gradually and consistently from the first years of life until an age of approximately 55 years. At this age, the AA is essentially considered to be zero and what is... more

- by Ana Barrio
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- Aging, Visual acuity, Accommodation, Clinical

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.

- by Rebecca Ivers
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- Clinical Trial, Quality of life, Older people, Randomised Controlled Trial

The aim was to determine world-wide patterns of fitting contact lenses for the correction of presbyopia. Methods: Up to 1,000 survey forms were sent to contact lens fitters in each of 38 countries between January and March every year over five consecutive years (2005 to 2009). Practitioners were asked to record data relating to the first 10 contact lens fittings or refittings performed after receiving the survey form. Results: Data were received relating to 16,680 presbyopic (age 45 years or older) and 84,202 pre-presbyopic (15 to 44 years) contact lens wearers. Females are over-represented in presbyopic versus pre-presbyopic groups, possibly reflecting a stronger desire for the cosmetic benefits of contact lenses among older women. The extent to which multifocal and monovision lenses are prescribed for presbyopes varies considerably among nations, ranging from 79 per cent of all soft lenses in Portugal to zero in Singapore. There appears to be significant under-prescribing of contact lenses for the correction of presbyopia, although for those who do receive such corrections, three times more multifocal lenses are fitted compared with monovision fittings. Presbyopic corrections are most frequently prescribed for full-time wear and monthly replacement. Conclusions: Despite apparent improvements in multifocal design and an increase in available multifocal options in recent years, practitioners are still under-prescribing with respect to the provision of appropriate contact lenses for the correction of presbyopia. Training of contact lens practitioners in presbyopic contact lens fitting should be accelerated and clinical and laboratory research in this field should be intensified to enhance the prospects of meeting the needs of presbyopic contact lens wearers more fully.

- by Craig Woods
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- Adolescent, Contact Lenses, Child, Physical sciences

Purpose. At a fixed viewing distance (VD), reading speed increases with print size. It is not known if this holds for computer tasks when postures are not constrained. Reflective glare on a monitor may reduce productivity. The effects of both may be modified by age. We evaluated effects of age, font size, and glare on performance for visually demanding text-based tasks on a computer. Methods. Nineteen young (18 to 35 years old) and eight older (55 to 65 years old wearing progressive lenses that correct for presbyopia) subjects participated in a study with two trial factors: font size (1.78, 2.23, and 3.56 mm) and glare (produced by bright light-emitting diode task light reflective off a matte liquid crystal display monitor). The monitor location was fixed but subjects were allowed to change their posture and move the chair. Subjects performed visual tasks that required similar visual skills to common tasks such as Internet use, data entry, or word processing. Results. Productivity, accuracy, and VD increased as font size increased. For each 1-mm increase in font size, there was a mean productivity gain of 3 correct clicks/min and an improvement in accuracy of 2%. Font size increase also led to lowered perceived task difficulty. Adding reflective glare on the monitor surface led to a reduced VD but had no effect on productivity or accuracy. With visual corrections for presbyopia, age had no effect on these relationships. Conclusions. Productivity is improved when the font is increased from 1.78 or 2.23 to 3.56 mm for text-based computer tasks. The largest font size corresponds to a visual angle of font of 23.4 arcmin. This visual angle of font is above the high end of ISO recommendations (International Organization for Standardization, 1992Standardization, , 2011. The findings may be useful for setting the font sizes for computers and for training office workers. (Optom Vis Sci 2014;91:682Y689)

- by James Sheedy
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- Aging, Reading, Adolescent, Visual acuity

Според Световната Здравна Организация през 2018г. в световен мащаб повече от 1,8 билиона човека страдат от пресбиопия. Броят им нараства бързо поради застаряващото глобално население.
Пресбиопията (Presbys=стар, ops=поглед) или възрастовото далекогледство представлява невъзможност за ясно виждане наблизо поради физиологично възрастово намаляване на обема на акомодация. С напредване на възрастта възможностите на окото да акомодира намаляват, тъй като лещата губи своята еластичност и все по- трудно променя формата си към сферична. Появява се така наречения „синдром на дългите ръце“- пациентите отдалечават текста, за да стане по- ясен и четлив.

- by Zornitsa Dicheva
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- Optics, Ophtalmology, Optometry and Ophthalmology, Presbyopia
- by Adrian Bruce
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- Aging, Convergence, Adolescent, Biological Sciences
- by Eileen Birch
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- Binocular vision, Depth Perception, Visual System, American

Background Unmet expectations are a major cause of client dissatisfaction, yet very little is known about the expectations and health values that clients in optometry practice hold about having an eye examination and purchasing spectacles. This study identified different attitudes and behaviours held by presbyope clients in optometric practices.

- by Jacques Desallais
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- Psychology, Nursing, Optometry, Decision Making

Background: There is limited information regarding the prevalence of presbyopia in different parts of the world. The add power and the prevalence of presbyopia by age and gender in general population of Shahroud, north of Iran, were... more

- by Abbasali Yekta
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- Iran, Clinical, Risk factors, Clinical Sciences
- by Oliver Findl
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- Polymers, Clinical Sciences, Optometry and Ophthalmology, Phacoemulsification

The monovision concept of correcting one eye for distance and the other for near maybe utilized in presbyopes undergoing refractive surgery. We have performed a systematic review of published literature to evaluate the factors influencing monovision success, and to determine the visual outcome in patients with monovision. Articles in MEDLINE and published bibliographies reporting monovision prescription for correction of presbyopia were systematically identified and reviewed. Pertinent data were abstracted and, when feasible, statistically analyzed. The mean success rate was 73%. The success in monovision correlated with distance correction on dominant eye, alternating dominance, less than 50 seconds of arc stereoacuity reduction, and less than 0.6 prism diopter of distance esophoric shifts. Monovision resulted in significant reduction of binocular contrast sensitivity function at spatial frequencies higher than 4 cycles per degree, and 2–6% reduction in task performance, but resulted in minimal reduction of binocular visual acuity, peripheral vision, visual field width and binocular depth of focus. The published literature indicates that monovision is an effective and reasonable therapeutic modality for correcting presbyopia. Proper patient selection and clinical screening are essential for monovision success.

- by Sandeep Jain
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- Binocular vision, Peripheral vision, Visual acuity, Contact Lenses

There are several methods for presbyopia treatment. Refractive lens exchange (RLE) followed by multifocal intraocular lens (MFIOL) implantation enables high rate of spectacle independence but have some visual disturbances. Laser in Situ Keratomileusis (LASIK) monovision gives patient ability to have good distant vision with dominant eye and good near vision with nondominant eye. In this prospective randomized study we wanted to compare clinical outcomes in patients who underwent either of the mentioned procedures. The first group included 50 patients (N = 100 eyes) who underwent RLE with MFIOL implantation and the second group included 50 patients (N = 100 eyes) who underwent LASIK monovision as presbyopia treatment. Uncorrected distant, near and intermediate visual acuity, patient's subjective satisfaction and visual disturbances were measured. Follow up was 6 months. Patients in RLE group had better near uncorrected visual acuity (UCVA) and patients in LASIK monovision group h...

- by Iva Dekaris and +1
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- Anthropology, Treatment Outcome, Visual acuity, Prospective studies

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.

- by Zbigniew Jaroszewicz
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- Computer Aided Design, Lenses, Optical physics, Reproducibility of Results

To evaluate to what extent the modification of corneal asphericity to induce spherical aberration (SA) can improve the depth of focus and to determine whether preoperative adaptive optics assessment (Voptica SL) can predict an optimal SA... more

- by Pablo Artal
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- Ophthalmology, Visual acuity, Prospective studies, Depth Perception

We explored the relative changes in ocular, corneal, and internal aberrations associated with normal aging with special emphasis in the role of ocular alignment and lens shape factor in the balance of aberrations. Ocular and corneal aberrations together with the angle kappa were measured for a 5-mm pupil diameter in 46 eyes with low refractive errors and ages ranging between 20 and 77 years. The root mean square (RMS) of the higher order ocular and corneal aberrations increased with age at a rate of 0.0032 2m/year and 0.0015 2m/year, respectively. While in young eyes the partial compensation of aberrations by the internal surfaces was clear, no significant difference was found between corneal and ocular RMS in the older group. The ocular spherical aberration (0.0011 2m/year) and horizontal coma (0.0017 2m/year) increased moderately with age. This is not due to changes in the optical alignment, since angle kappa did not vary significantly with age. Age-related variations in the radii of curvature of the crystalline lens modify slightly its shape factor, reducing the compensation of lateral coma. This suggests that geometrical changes in the crystalline lens with age contribute to modify its aberration structure, reducing the compensation mechanism and explaining most of the measured increment of ocular aberrations with age.

- by Pablo Artal
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- Optics, Aging, Coma, Vision
- by Urs Mosimann and +1
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- Algorithms, Praxis, Dementia, Risk assessment

Introduction
Uncorrected refractive error is the leading cause of visual impairment worldwide and leads to an impaired quality of life. This study was designed to determine the prevalence of uncorrected refractive error and presbyopia, to assess spectacle coverage, and to evaluate visual health-related quality of life among persons aged 15–50 years old in Nampula, Mozambique.
Methods
Participants were assessed using a validated rapid assessment of refractive error protocol, comprised of a demographic questionnaire, a standardized ophthalmic assessment to determine refractive status and spectacle coverage, and a modified vision-related quality of life questionnaire to assess the impact of uncorrected refractive error on participants’ visual health status.
Results
Among the 3,453 respondents, visual impairment prevalence was 3.5%

- by Stephen J Thompson
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- Optometry, Development Studies, International Development, Africa

Multifocal intraocular lenses (MFIOL) enable good near and far vision after cataract surgery. Excellent results with cataract patients encouraged ophthalmologists to implant MFIOL after clear lens extraction (CLE). There are two types of MFIOL: diffractive and refractive. In our prospective study we compared clinical outcomes after CLE and bilateral implantation of diffractive (Tecnis Multifocal), (N=100 eyes, 50 patients) and refractive (ReZoom), (N=100 eyes, 50 patients) MFIOL to patients with presbyopia and hyperopia. Near and distant uncorrected visual acuity (UCVA), spectacle dependency, subjective satisfaction and visual disturbances were measured and compared between two groups. Patients achieved good near and distant UCVA in both groups. "Tecnis" group had better near UCVA (statistically not significant) and less night time visual disturbances. "ReZoom" group reported less problems with intermediate vision. Diffractive and refractive MFIOL enable high rat...

- by Ivana Romac and +1
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- Anthropology, Visual acuity, Patient Satisfaction, Refractive Indices

Magnetic Resonance Imaging was used to study changes in the crystalline lens and ciliary body with accommodation and aging. Monocular images were obtained in 15 young (19-29 years) and 15 older (60-70 years) emmetropes when viewing at far (6 m) and at individual near points (14.5 to 20.9 cm) in the younger group. With accommodation, lens thickness increased (mean T 95% CI: 0.33 T 0.06 mm) by a similar magnitude to the decrease in anterior chamber depth (0.31 T 0.07 mm) and equatorial diameter (0.32 T 0.04 mm) with a decrease in the radius of curvature of the posterior lens surface (0.58 T 0.30 mm). Anterior lens surface shape could not be determined due to the overlapping region with the iris. Ciliary ring diameter decreased (0.44 T 0.17 mm) with no decrease in circumlental space or forward ciliary body movement. With aging, lens thickness increased (mean T 95% CI: 0.97 T 0.24 mm) similar in magnitude to the sum of the decrease in anterior chamber depth (0.45 T 0.21 mm) and increase in anterior segment depth (0.52 T 0.23 mm). Equatorial lens diameter increased (0.28 T 0.23 mm) with no change in the posterior lens surface radius of curvature. Ciliary ring diameter decreased (0.57 T 0.41 mm) with reduced circumlental space (0.43 T 0.15 mm) and no forward ciliary body movement. Accommodative changes support the Helmholtz theory of accommodation including an increase in posterior lens surface curvature. Certain aspects of aging changes mimic accommodation.

- by James M Pope
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- Magnetic Resonance Imaging, Aging, Vision, Young Adult

- by Zbigniew Jaroszewicz
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- Computer Aided Design, Lenses, Optical physics, Reproducibility of Results

- by Jose Alfonso
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- Ophthalmology, Surgery, Binocular vision, Treatment

Purpose. The purpose of this study is to assess the visual performance of subjects wearing gas-permeable (GP) multifocal contact lenses, soft bifocal contact lenses, GP monovision lenses and spectacles. Methods. The study included 32 subjects between the ages of 42 and 65 years wearing GP monovision, the Acuvue Bifocal (Vistakon), the Essentials GP Multifocal (Blanchard), and progressive addition lenses (PAL; spectacles group). There were eight subjects in each of these groups who were already wearing these modalities. Binocular low (18%) and high (95%) contrast acuities were recorded using the Bailey-Lovie chart; binocular contrast sensitivity from 1.5 to 18 cycles per degree (cpd) measured with the Vistech VCTS 6500 system, and monocular glare sensitivity at three luminance settings (400, 100, and 12 foot lamberts) was measured using the brightness acuity tester (BAT). Binocular near visual task performance (a modified version of letter counting method used in previous presbyopic studies) was also assessed. Results. For the contact lens-wearing groups, subjects wearing GP multifocals provided the best binocular high and low contrast acuity followed by soft bifocal wearers. There was relative parity between the binocular high and low contrast acuity with PAL and GP multifocal wearers. Monovision acuity, measured binocularly, was determined to be lower than the other three groups with this difference being most significant with high contrast acuity. Among contact lens-wearing groups, it was observed that GP multifocal lens wearers experienced the lowest amount of monocular disability glare followed by soft bifocal wearers and monovision wearers. Subjects wearing soft bifocal lenses and monovision demonstrated slightly reduced binocular contrast sensitivity at all spatial frequencies. In the contact lens groups, GP multifocal lens wearers had the highest binocular contrast sensitivity at all spatial frequencies, on parity with PAL wearers, except at the highest spatial frequency (18 cpd) at which PAL wearers had better vision. Error scores for the binocular near visual task performance between the four groups revealed subjects with GP multifocal lenses and PAL wearers to have the least errors, followed by monovision users and then soft bifocal wearers with the most errors. Conclusion. Subjects wearing GP multifocals, soft bifocals, monovision, and PAL spectacles have good binocular contrast sensitivity, satisfactory binocular low and high contrast acuity, and increased sensitivity to glare. Presbyopic subjects requiring the use of contact lenses under dim light levels could benefit from GP multifocal lenses. Contrast and glare sensitivity evaluations provide significant information regarding the visual performance of the presbyopic contact lenses and should be included in regular presbyopic contact lens fitting. (Optom Vis Sci 2006;83:611-615)

- by Vasudevan Lakshminarayanan
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- Binocular vision, Visual acuity, Contact Lenses, Visual Performance

To evaluate long-term outcomes of small-aperture corneal inlay implantation for the surgical compensation of presbyopia. Paracelsus Medical University, Salzburg, Austria. Prospective interventional cohort study. Monocular implantation of a Kamra small-aperture inlay (model ACI7000) (1.6 mm central aperture) was performed in emmetropic presbyopic eyes. The preoperative and postoperative parameters included monocular and binocular uncorrected (UDVA) and corrected (CDVA) distance visual acuities, uncorrected intermediate visual acuity (UIVA), and uncorrected (UNVA) and corrected (CNVA) near visual acuities; refraction; patient satisfaction; and complications. From September 4, 2006, to May 21, 2007, a small-aperture inlay (1.6 mm central aperture) was implanted in 32 emmetropic presbyopic eyes. The mean binocular uncorrected visual acuities improved as follows: UNVA from Jaeger (J) 6 ± 1.2 lines (∼20/50) to J2 ± 1.8 lines (∼20/25) (P < .001) and UIVA from 0.2 logMAR ± 1.3 lines (∼20...

- by Alois Dexl and +1
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- Binocular vision, Treatment Outcome, Visual acuity, Prospective studies

The monovision concept of correcting one eye for distance and the other for near may be utilized in presbyopes undergoing refractive surgery. We have performed a systematic review of published literature to evaluate the factors influencing monovision success, and to determine the visual outcome in patients with monovision. Articles in MEDLINE and published bibliographies reporting monovision prescription for correction of presbyopia were systematically identified and reviewed. Pertinent data were abstracted and, when feasible, statistically analyzed. The mean success rate was 73%. The success in monovision correlated with distance correction on dominant eye, alternating dominance, less than 50 seconds of arc stereoacuity reduction, and less than 0.6 prism diopter of distance esophoric shifts. Monovision resulted in significant reduction of binocular contrast sensitivity function at spatial frequencies higher than 4 cycles per degree, and 2-6% reduction in task performance, but resulted in minimal reduction of binocular visual acuity, peripheral vision, visual field width and binocular depth of focus. The published literature indicates that monovision is an effective and reasonable therapeutic modality for correcting presbyopia. Proper patient selection and clinical screening are essential for monovision success. (Surv Ophthalmol 40:491-499, 1996)

- by Sandeep Jain
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- Binocular vision, Peripheral vision, Visual acuity, Contact Lenses

The optical correction of presbyopia must be handled individually. Our aim was to compare the methods used in addition to the refractive near vision, with the final addition used in presbyopic patients. Methods: Eighty healthy subjects with a mean age of 49.7 years (range 40 to 60 years) were studied. Tentative near additions were determined using four different techniques: one-half amplitude accommodation with minus lenses (AAL); one-third accommodative demand with positive lens (ADL); balanced range of accommodation with minus and positive lenses (BRA) and crossed cylinder test with initial myopisation (CCT). The power of the addition was then refined to ar rive at the final addition. Results: The mean tentative near additions were lower than the final addition for ADL and BRA addition methods. The mean differences between tentative and final additions were low for all the tests examined (less than 0.25 D). The intervals between the 95% limits of agreement differed substantially and were always higher than ±0.50 D. Conclusion: All the methods used displayed similar behavior and provided a tentative addition close to the final addition. The coefficient of agreements (COA) detected suggests that every tentative addition should be adjusted according to the particular needs of the patient.

- by Daniel O Dantas and +1
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- Visual acuity, Depth Perception, Optometry and Ophthalmology, Reproducibility of Results
- by Mark Packer
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- Cataract, Optometry and Ophthalmology, prosthesis Design, Presbyopia

To evaluate visual function in patients with early presbyopia using the functional visual acuity (FVA) test. This study included 27 eyes of 27 healthy older volunteers (mean age, 44.1 ± 2.6 years) and 14 eyes of 14 healthy young volunteers (mean age, 28.4±4.8 years). The distance-corrected visual acuity (DCVA), distance-corrected near VA (DCNVA), subjective amplitude of accommodation (AA), and distance and near pupillary diameters were measured. The distance FVA and distance-corrected near FVA (DCNFVA) were measured using the FVA Measurement System. The standard Schirmer test and standard tear break-up time measurement also were performed. The logarithm of the minimum angle of resolution (logMAR) DCVA was better than 0 in all subjects. The percentages of subjects with logMAR DCNVA below 0 was significantly lower in the presbyopia group than in the young group. The DCNFVA in the presbyopia group was significantly (P < 0.001) poorer than the DCNVA in that group. Significant linear ...

- by Yuta Shigeno
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- Medicine, Multidisciplinary, Visual acuity, Young Adult

- by ebrahim jafarzadehpur
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- Iran, Clinical, Risk factors, Clinical Sciences

With the recent introduction of potentially accommodative intraocular lenses (IOL), there is a need for methods to evaluate their accommodative potential. In most studies assessing IOL movement, pilocarpine is used to stimulate contraction of the ciliary muscle. The aim of this study is to determine if pilocarpine-induced ciliary muscle contraction is comparable to physiological stimulus-driven accommodation in young and presbyopic subjects.

- by Oliver Findl
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- Biometry, Accommodation, Optometry and Ophthalmology, Pilocarpine

There are isolated reports that accommodative response is reduced in some populations with low vision. The purpose of this study was to measure accommodative response in a wider range of pre-presbyopes with visual impairment and to examine what factors may affect accommodation among the low vision population. METHODS. Accommodative responses for accommodative demands between 4 and 10 D were measured with dynamic retinoscopy in 21 subjects with low vision due to a variety of disorders and in 40 control subjects, aged 3 to 35 years. The control subjects were divided into age groups of 3 to 5, 6 to 10, 11 to 26, and 27 to 35 years, and the response of each subject with low vision was compared against the age-matched control group. The slope of the accommodative function and the mean error of the accommodative response were also calculated. RESULTS. Eighty-six percent of the subjects with low vision showed responses that were outside the 95% range of normal. The deficit increased with increasing accommodative demand. Reduced accommodation was not predicted by age, visual acuity, presence of nystagmus, refractive error or time of onset of the disorder. The results show that the accommodation errors are often greater than predicted by increased depth of focus due to poor visual acuity. CONCLUSIONS. It seems likely that accommodative response is based on many factors that may be present in an eye with low vision, which interact in a complex fashion. (Invest Ophthalmol Vis Sci.

- by Susan Leat
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- Adolescent, Visual acuity, Biological Sciences, Refractive Error

Multifocal vision corrections are increasingly used solutions for presbyopia. In the current study we have evaluated, optically and psychophysically, the quality provided by multizone radial and angular segmented phase designs. Optical and relative visual quality were evaluated using 8 subjects, testing 6 phase designs. Optical quality was evaluated by means of Visual Strehl-based-metrics (VS). The relative visual quality across designs was obtained through a psychophysical paradigm in which images viewed through 210 pairs of phase patterns were perceptually judged. A custom-developed Adaptive Optics (AO) system, including a Hartmann-Shack sensor and an electromagnetic deformable mirror, to measure and correct the eye's aberrations, and a phase-only reflective Spatial Light Modulator, to simulate the phase designs, was developed for this study. The multizone segmented phase designs had 2-4 zones of progressive power (0 to +3D) in either radial or angular distributions. The respo...

- by Maria Vinas
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- Psychophysics, Computer Science, Medicine, Contact Lenses

The relative contribution of tonic vergence to the maximum near vergence response as a function of age and the development of presbyopia has received little attention. Tonic vergence position was measured subjectively in a group of 50 subjects between 20 and 68 years of age. While there was no progressive trend with age, tonic vergence did exhibit a small but consistent convergent increase after 40 years of age. Thus, tonic vergence showed a slight change, possibly of a motor adaptive nature, concurrent with increasing age and the development of clinical presbyopia. ,

- by ken ciuffreda
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- Aging, Clinical Sciences, Aged, Optometry and Ophthalmology

To evaluate the effect of the KAMRA corneal inlay on the retinal image brightness in the peripheral visual field. A KAMRA inlay was "implanted" into a theoretical eye model in a corneal depth of 200 microns. Corneal radius was varied to a steep, normal, and flat (7.37, 7.77, and 8.17 mm) version keeping the proportion of anterior to posterior radius constant. Pupil size was varied from 2.0 to 5.0 mm. Image brightness was determined for field angles from -70° to 70° with and without KAMRA and proportion of light attenuation was recorded. In our parameter space, the attenuation in brightness ranges in between 0 and 60%. The attenuation in brightness is not affected by corneal shape. For large field angles where the incident ray bundle is passing through the peripheral cornea, brightness is not affected. For combinations of small pupil sizes (2.0 and 2.5 mm) and field angles of 20-40°, up to 60% of light may be blocked with the KAMRA. For combinations of pupil sizes and field...

- by Timo Eppig
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- Technology, Cornea, Biological Sciences, Light

- by Jose Alfonso
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- Ophthalmology, Surgery, Binocular vision, Treatment