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Clinical & Experimental Optometry May 2008Understanding the normal functioning of the human lens and its role in the development of disorders of vision, such as presbyopia and cataract, requires a thorough... (Review)
Review
Understanding the normal functioning of the human lens and its role in the development of disorders of vision, such as presbyopia and cataract, requires a thorough knowledge of how the lens grows and how its properties change with age. Many of these properties can be obtained only by studying the isolated organ in vitro. In addition, because of the difficulties in obtaining human tissues, animal lenses are frequently used as models for the human lens. Information is needed for these as well. In this review, current knowledge of lens growth and factors that affect growth are examined in a variety of species. Topics covered include changes in lens weight, dimensions, stiffness and refractive index distribution with age and the influence of other factors such as gender, environment and body size. From these, it has become clear that lens growth is not greatly affected by external influences. Although there are many similarities in the growth of lenses from different species, humans (and probably all primates) have distinctly different growth patterns, with prenatal and postnatal growth having different regulatory mechanisms. As a result, human lens properties are different from those of other species. Unfortunately, many of the published data are unreliable, presumably because of post-mortem changes, making it difficult to extrapolate in vitro observations to the in vivo situation.
Topics: Aging; Biomechanical Phenomena; Embryonic Development; Fetus; Humans; In Vitro Techniques; Lens, Crystalline; Models, Biological; Organ Size; Presbyopia; Risk Factors
PubMed: 18331361
DOI: 10.1111/j.1444-0938.2008.00255.x -
American Journal of Ophthalmology Sep 2023To evaluate the safety, efficacy, and pharmacokinetics of pilocarpine hydrochloride 1.25% (Pilo hereafter) compared with vehicle when administered bilaterally, twice... (Randomized Controlled Trial)
Randomized Controlled Trial
PURPOSE
To evaluate the safety, efficacy, and pharmacokinetics of pilocarpine hydrochloride 1.25% (Pilo hereafter) compared with vehicle when administered bilaterally, twice daily (6 hours apart) for 14 days in participants with presbyopia.
DESIGN
Phase 3, randomized (1:1), controlled, double-masked, multicenter study.
METHODS
Participants (40-55 years of age) had objective and subjective evidence of presbyopia affecting daily activities with mesopic, high-contrast, binocular distance-corrected near visual acuity (DCNVA) of 20/40 to 20/100. The primary/key secondary endpoint was the proportion of participants gaining ≥3 lines in mesopic/photopic, high-contrast, binocular DCNVA on day 14 (last study visit), hour 9 (3 hours after the second dose), with no more than a 5-letter loss in mesopic/photopic corrected distance visual acuity with the same refractive correction. Key safety measures included treatment-emergent adverse events (TEAEs) and some ocular measurements. Pilocarpine plasma levels were assessed in approximately 10% of enrolled participants.
RESULTS
Overall, 230 participants were randomized to Pilo twice daily (N = 114) and vehicle (N = 116). The proportion of participants achieving the primary and key secondary efficacy endpoints was statistically significantly greater with Pilo twice daily than vehicle, with between-treatment differences of 27.3% (95% CI = 17.3, 37.4) and 26.4% (95% CI = 16.8, 36.0), respectively. The most common TEAE was headache, reported in 10 participants (8.8%, Pilo group) and 4 participants (3.4%, vehicle group). Pilocarpine's accumulation index on day 14 was ≤1.11 after the second dose.
CONCLUSIONS
Near-vision improvements were statistically greater with Pilo twice daily than with vehicle, without compromising distance acuity. The safety profile of Pilo twice daily was consistent with that of Pilo once daily, and systemic accumulation was minimal, supporting twice daily administration.
Topics: Humans; Pilocarpine; Presbyopia; Visual Acuity; Refraction, Ocular; Double-Blind Method
PubMed: 37149245
DOI: 10.1016/j.ajo.2023.05.008 -
Current Biology : CB Aug 2019Monovision is a common prescription lens correction for presbyopia [1]. Each eye is corrected for a different distance, causing one image to be blurrier than the other....
Monovision is a common prescription lens correction for presbyopia [1]. Each eye is corrected for a different distance, causing one image to be blurrier than the other. Millions of people have monovision corrections, but little is known about how interocular blur differences affect motion perception. Here, we report that blur differences cause a previously unknown motion illusion that makes people dramatically misperceive the distance and three-dimensional direction of moving objects. The effect occurs because the blurry and sharp images are processed at different speeds. For moving objects, the mismatch in processing speed causes a neural disparity, which results in the misperceptions. A variant of a 100-year-old stereo-motion phenomenon called the Pulfrich effect [2], the illusion poses an apparent paradox: blur reduces contrast, and contrast reductions are known to cause neural processing delays [3-6], but our results indicate that blurry images are processed milliseconds more quickly. We resolve the paradox with known properties of the early visual system, show that the misperceptions can be severe enough to impact public safety, and demonstrate that the misperceptions can be eliminated with novel combinations of non-invasive ophthalmic interventions. The fact that substantial perceptual errors are caused by millisecond differences in processing speed highlights the exquisite temporal calibration required for accurate perceptual estimation. The motion illusion-the reverse Pulfrich effect-and the paradigm we use to measure it should help reveal how optical and image properties impact temporal processing, an important but understudied issue in vision and visual neuroscience.
Topics: Adult; Depth Perception; Female; Humans; Illusions; Male; Motion; Motion Perception; Presbyopia; Vision, Monocular; Young Adult
PubMed: 31353183
DOI: 10.1016/j.cub.2019.06.070 -
Journal of the West African College of... 2022To determine the prevalence of presbyopia, near vision spectacle use, and near vision spectacle coverage among cosmetologists in Mushin Local Government Area of Lagos...
OBJECTIVE
To determine the prevalence of presbyopia, near vision spectacle use, and near vision spectacle coverage among cosmetologists in Mushin Local Government Area of Lagos State with the view of creating awareness, improving productivity and quality of life.
MATERIALS AND METHODS
This was a descriptive cross-sectional study, conducted among 251 cosmetologists aged ≥ 30 years. All participants had a standardized protocol including visual acuity assessment (distance and near), anterior and posterior segment examinations, and refraction. Spectacle usage, work, productivity impact, and near vision-related quality of life (NVQoL) information were obtained with the 12-item Near Vision-Related Quality of Life Questionnaire, the Spectacle Usage section of the World Health Organisation (WHO) Spectacle and Work Productivity Questionnaire. Data obtained was analysed using Statistical Package for Social Sciences version 23 (IBM Corp. Armonk, NY).
RESULTS
Two hundred and fifty-one cosmetologists were studied with a male to female ratio of 1:6.4 and overall mean age of 43.9 ± 6.5 years. The prevalence of presbyopia was 67.3% and the unmet need was 51.3%. Eighty-four percent of presbyopic participants reported severe difficulty with their NVQoL compared to 16% of non-presbyopes. There was a statistically significant association between uncorrected presbyopia and reduced NVQoL ( < 0.001).
CONCLUSION
This study demonstrated a relatively high prevalence of presbyopia, high unmet need, and a significant reduction in the near vision-related quality of life. This indicates the need for improved access to refractive services and spectacles among this group of artisans in whom near vision plays an indispensable role.
PubMed: 36388744
DOI: 10.4103/jwas.jwas_149_22 -
Eye and Vision (London, England) 2017Presbyopia affects people from the 4 decade of life and is characterized by accommodative loss that leads to negative effects on vision-targeted health-related quality... (Review)
Review
INTRODUCTION
Presbyopia affects people from the 4 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 providing near-lenses independence would be a truly groundbreaking approach in the treatment of presbyopia. The purpose of this review is to analyze the emerging pharmacological solutions proposed to address presbyopia.
RESULTS
Several ophthalmic eye drops compounds solutions have been described in peer-reviewed papers or presented in ophthalmological tabloids and congresses. Each topical treatment deals with drug combinations aimed to modify one or more factors involved in the accommodative process and have been proposed to be instilled either monocularly or binocularly. It remains unclear how much each drug in the final combined form is involved in the achievement of the outcome and contributes to it.
CONCLUSION
Despite the lack of a completely well understood mechanism, pharmacological control of presbyopia seems to be a possible and very attractive alternative for presbyopic patients. The studies mentioned in this review are to be considered pilot investigations as they involve either a small number of subjects or are single case series. Complete studies are needed to confirm which will be the more effective pharmacological compound for the treatment of presbyopia.
PubMed: 28191476
DOI: 10.1186/s40662-017-0068-8 -
International Journal of Ophthalmology 2017A systematic review of the recent literature regarding pseudophakic monovision as a reliable methods for presbyopia correction was performed based on the PubMed,... (Review)
Review
A systematic review of the recent literature regarding pseudophakic monovision as a reliable methods for presbyopia correction was performed based on the PubMed, MEDLINE, Nature and the American Academy of Ophthalmology databases in July 2015 and data from 18 descriptive and 12 comparative studies were included in this narrative review. Pseudophakic monosvision seems to be an effective method for presbyopia with high rates of spectacles independence and minimal dysphotopsia side-effects, that should be considered by the modern cataract surgeons.
PubMed: 28730093
DOI: 10.18240/ijo.2017.06.24 -
Journal of Patient-reported Outcomes Nov 2021Presbyopia is defined as the age-related deterioration in the ability to focus on close objects, causing difficulty with near vision tasks. The study aim was to...
BACKGROUND
Presbyopia is defined as the age-related deterioration in the ability to focus on close objects, causing difficulty with near vision tasks. The study aim was to understand the lived experience of phakic presbyopia and identify all relevant visual function symptoms and associated functional impacts.
METHODS
Fifty individuals with clinician-confirmed phakic presbyopia (US n = 30, France n = 10, Germany n = 10) and seven healthcare professionals (HCPs) participated in in-depth, face-to-face, qualitative concept elicitation interviews. Verbatim transcripts were analyzed using thematic analysis methods.
RESULTS
Visual function symptoms reported by participants with phakic presbyopia were categorized as: primary near vision functioning symptoms (impaired near visual acuity, n = 50/50, 100%; difficulty with near vision in dim light, n = 42/50, 84%; difficulty focusing at close distances, n = 30/50, 60%; difficulty seeing things when glare is present, n = 30/50, 60%) and secondary symptoms (eye strain, n = 37/50, 74%; dry eyes, n = 35/50, 70%; headaches, n = 30/50, 60%). Proximal impacts on functional vision included difficulty reading in near vision (n = 49/50, 98%, including printed text and handwriting), seeing objects in near vision n = 48/50, 96%, and performing activities of daily living that require near vision (n = 49/50, 98%, including using a smartphone or computer). Distal impacts on functional vision included emotional, work, financial and social impacts. HCP interviews supported participant findings.
CONCLUSION
Findings provide a comprehensive understanding of the lived experience of phakic presbyopia which informed the development of a presbyopia conceptual model and patient-reported outcome assessments of vision correction independence and near vision functioning. The sample did not include those whose vision cannot be adequately corrected with lenses or surgery.
PubMed: 34731344
DOI: 10.1186/s41687-021-00383-1 -
Scientific Reports May 2023A new presbyopia-correcting intraocular lens (IOL) combining bifocal and extended-depth-of-focus profiles (Symbiose: Artis Symbiose Plus; Cristalens Industrie, Lannion,...
A new presbyopia-correcting intraocular lens (IOL) combining bifocal and extended-depth-of-focus profiles (Symbiose: Artis Symbiose Plus; Cristalens Industrie, Lannion, France) was introduced. We compared the output with that of a standard monofocal IOL (PL E: Artis PL E). The two four-haptic hydrophobic IOLs were made of the same material from the same company. Cataract patients bilaterally implanted with either PL E or Symbiose between November 2021 and August 2022 were reviewed. The principal measures of the postoperative results were uncorrected distance visual acuity (UDVA); corrected distance VA (CDVA); uncorrected intermediate VA; uncorrected near VA; objective optical quality; and distance-corrected defocus curves. This study included forty-eight patients (96 eyes), with 22 and 26 patients (44 and 52 eyes, respectively) being implanted with PL E and Symbiose, respectively. All patients received the same type of IOL implanted in both eyes. The average age of patients was 70.9 ± 7.1 and 60.0 ± 8.5 years in PL E and Symbiose groups, respectively, with significantly younger patients in Symbiose group (p < 0.001). Both IOLs displayed excellent UDVA and CDVA with no statistical difference (p = 0.081 (monocular UDVA), p = 0.599 (monocular CDVA), p = 0.204 (binocular UDVA), and p = 0.145 (binocular CDVA)). In comparison with PL E group, Symbiose group showed significantly superior postoperative intermediate and near VA (p < 0.001). PL E group showed significantly superior objective optical quality compared with Symbiose group (p < 0.001). Symbiose provides a continuous range of vision that ensures a seamless transition from far to near with no discontinuity. It also delivers a smooth defocus curve with a larger landing area than the PL E. But the objective optical quality was better in PL E.
Topics: Humans; Middle Aged; Aged; Presbyopia; Haptic Technology; Eye, Artificial; Lenses, Intraocular; Eye; Intraocular Lymphoma
PubMed: 37225829
DOI: 10.1038/s41598-023-35377-0 -
Arquivos Brasileiros de Oftalmologia 2023
Topics: Humans; Presbyopia; Accommodation, Ocular
PubMed: 37878949
DOI: 10.5935/0004-2749.2023-0196 -
The British Journal of Ophthalmology Jul 2007
Topics: Developing Countries; Eyeglasses; Health Services Needs and Demand; Humans; Presbyopia; Visual Acuity
PubMed: 17576703
DOI: 10.1136/bjo.2006.112862