-
Investigative Ophthalmology & Visual... Apr 2021The prevalence of myopia has markedly increased in East and Southeast Asia, and pathologic consequences of myopia, including myopic maculopathy and high... (Review)
Review
The prevalence of myopia has markedly increased in East and Southeast Asia, and pathologic consequences of myopia, including myopic maculopathy and high myopia-associated optic neuropathy, are now some of the most common causes of irreversible blindness. Hence, strategies are warranted to reduce the prevalence of myopia and the progression to high myopia because this is the main modifiable risk factor for pathologic myopia. On the basis of published population-based and interventional studies, an important strategy to reduce the development of myopia is encouraging schoolchildren to spend more time outdoors. As compared with other measures, spending more time outdoors is the safest strategy and aligns with other existing health initiatives, such as obesity prevention, by promoting a healthier lifestyle for children and adolescents. Useful clinical measures to reduce or slow the progression of myopia include the daily application of low-dose atropine eye drops, in concentrations ranging between 0.01% and 0.05%, despite the side effects of a slightly reduced amplitude of accommodation, slight mydriasis, and risk of an allergic reaction; multifocal spectacle design; contact lenses that have power profiles that produce peripheral myopic defocus; and orthokeratology using corneal gas-permeable contact lenses that are designed to flatten the central cornea, leading to midperipheral steeping and peripheral myopic defocus, during overnight wear to eliminate daytime myopia. The risk-to-benefit ratio needs to be weighed up for the individual on the basis of their age, health, and lifestyle. The measures listed above are not mutually exclusive and are beginning to be examined in combination.
Topics: Accommodation, Ocular; Contact Lenses; Disease Progression; Eyeglasses; Global Health; Humans; Myopia; Prevalence; Refraction, Ocular
PubMed: 33909032
DOI: 10.1167/iovs.62.5.6 -
Investigative Ophthalmology & Visual... Apr 2021The role of accommodation in myopia development and progression has been debated for decades. More recently, the understanding of the mechanisms involved in... (Review)
Review
The role of accommodation in myopia development and progression has been debated for decades. More recently, the understanding of the mechanisms involved in accommodation and the consequent alterations in ocular parameters has expanded. This International Myopia Institute white paper reviews the variations in ocular parameters that occur with accommodation and the mechanisms involved in accommodation and myopia development and progression. Convergence is synergistically linked with accommodation and the impact of this on myopia has also been critiqued. Specific topics reviewed included accommodation and myopia, role of spatial frequency, and contrast of the task of objects in the near environment, color cues to accommodation, lag of accommodation, accommodative-convergence ratio, and near phoria status. Aspects of retinal blur from the lag of accommodation, the impact of spatial frequency at near and a short working distance may all be implicated in myopia development and progression. The response of the ciliary body and its links with changes in the choroid remain to be explored. Further research is critical to understanding the factors underlying accommodative and binocular mechanisms for myopia development and its progression and to guide recommendations for targeted interventions to slow myopia progression.
Topics: Accommodation, Ocular; Convergence, Ocular; Disease Progression; Humans; Myopia; Refraction, Ocular; Vision, Binocular
PubMed: 33909034
DOI: 10.1167/iovs.62.5.4 -
Journal of Optometry 2022Convergence insufficiency (CI) is a common binocular vision (BV) disorder characterized by difficulty in maintaining motor fusion at near, which affects approximately... (Review)
Review
Convergence insufficiency (CI) is a common binocular vision (BV) disorder characterized by difficulty in maintaining motor fusion at near, which affects approximately 7.5 percent of the population. Diagnostic criteria for the disorder are inconsistent, ranging from one to many clinical signs. Methodology for clinical tests is inconsistent in measurement technique, visual targets, required repetitions, and normative values. This manuscript demonstrates the inconsistencies amongst published studies, and highlights the importance of consistent clinical diagnostic signs, measurement techniques, visual targets, and cut-off criteria. For each clinical sign, the recommended methodology for the procedure is described. Several studies do not take age into account when diagnosing CI in their cohorts. As such, the review emphasizes changes in diagnostic signs with age. This manuscript highlights the need for consistent and clear procedures and diagnostic criteria amongst clinicians and provides the basis for future studies in terms of diagnostic testing required for CI of varying age groups.
Topics: Accommodation, Ocular; Convergence, Ocular; Humans; Ocular Motility Disorders; Vision Disorders; Vision, Binocular
PubMed: 34963569
DOI: 10.1016/j.optom.2021.11.002 -
Asia-Pacific Journal of Ophthalmology... 2020Presbyopia reduces an individual's ability to perform visual tasks at near distances. It is a global problem, affecting over a billion people worldwide. Contact lenses,... (Review)
Review
Presbyopia reduces an individual's ability to perform visual tasks at near distances. It is a global problem, affecting over a billion people worldwide. Contact lenses, glasses, refractive surgery, and intraocular lens surgery are the main modalities in presbyopia treatment, although they all have some disadvantages. Thus, there is an increasing need for effective, easy-to-use, and noninvasive approaches for treating presbyopia while not limiting patients' daily activities. Pharmacological presbyopia treatment as an alternative method has been under investigation in recent years. We reviewed all relevant articles using the keywords "presbyopia," "presbyopia treatment," "pharmacological presbyopia treatment," and "presbyopic corrections" from 2010 to February 9, 2020, and summarized the main results of clinical trials, investigating the drops used for presbyopia treatment.
Topics: Accommodation, Ocular; Cyclooxygenase 2 Inhibitors; Drug Therapy, Combination; Humans; Muscarinic Agonists; Ophthalmic Solutions; Presbyopia; Refraction, Ocular; Treatment Outcome
PubMed: 32511122
DOI: 10.1097/APO.0000000000000297 -
Clinical & Experimental Optometry Jan 2020Evidence from animal and human studies suggests that ocular growth is influenced by visual experience. Reduced retinal image quality and imposed optical defocus result... (Review)
Review
Evidence from animal and human studies suggests that ocular growth is influenced by visual experience. Reduced retinal image quality and imposed optical defocus result in predictable changes in axial eye growth. Higher order aberrations are optical imperfections of the eye that alter retinal image quality despite optimal correction of spherical defocus and astigmatism. Since higher order aberrations reduce retinal image quality and produce variations in optical vergence across the entrance pupil of the eye, they may provide optical signals that contribute to the regulation and modulation of eye growth and refractive error development. The magnitude and type of higher order aberrations vary with age, refractive error, and during near work and accommodation. Furthermore, distinctive changes in higher order aberrations occur with various myopia control treatments, including atropine, near addition spectacle lenses, orthokeratology and soft multifocal and dual-focus contact lenses. Several plausible mechanisms have been proposed by which higher order aberrations may influence axial eye growth, the development of refractive error, and the treatment effect of myopia control interventions. Future studies of higher order aberrations, particularly during childhood, accommodation, and treatment with myopia control interventions are required to further our understanding of their potential role in refractive error development and eye growth.
Topics: Accommodation, Ocular; Astigmatism; Contact Lenses, Hydrophilic; Corneal Wavefront Aberration; Eye; Eyeglasses; Humans; Myopia; Orthokeratologic Procedures; Refractive Errors
PubMed: 31489693
DOI: 10.1111/cxo.12960 -
Journal Francais D'ophtalmologie Dec 2021The digital revolution, which has been underway since the 1980's, is disrupting our daily routines with an exponential increase in the use of screens, which has not been... (Review)
Review
The digital revolution, which has been underway since the 1980's, is disrupting our daily routines with an exponential increase in the use of screens, which has not been without consequence to our visual system. Digital eye strain (DES), or computer vision syndrome (CVS), includes all the visual symptoms secondary to the use of digital devices. DES is present in at least 50% of regular users of digital media and is defined by blurred vision, difficulty focusing, ocular irritation or burning, dry eye, visual fatigue, headaches and increased sensitivity to light. Exposure time, age, female gender, and work environment are the main factors increasing its prevalence. Its pathophysiology, still poorly understood, is felt to be multifactorial and includes disturbances in the accommodative-convergence balance and changes in the ocular surface. Regarding accommodation and convergence, the studies are mostly old and their results heterogeneous. Conversely, many studies have shown an increase in the prevalence of dry eye in screen users. Although the retinal toxicity of blue light has been proven in in vitro models, the low level of evidence in the available studies does not allow it to be clearly correlated with the symptoms of DES. The objective of this review is to condense the knowledge available in the literature on the symptoms, prevalence, pathophysiology and management of DES.
Topics: Accommodation, Ocular; Asthenopia; Dry Eye Syndromes; Female; Humans; Internet; Prevalence
PubMed: 34657757
DOI: 10.1016/j.jfo.2020.10.002 -
Ophthalmology Jul 2020To evaluate the efficacy and safety of 0.05%, 0.025%, and 0.01% atropine eye drops over 2 years to determine which is the optimal concentration for longer-term myopia... (Randomized Controlled Trial)
Randomized Controlled Trial
PURPOSE
To evaluate the efficacy and safety of 0.05%, 0.025%, and 0.01% atropine eye drops over 2 years to determine which is the optimal concentration for longer-term myopia control.
DESIGN
Randomized, double-masked trial extended from the Low-Concentration Atropine for Myopia Progression (LAMP) Study.
PARTICIPANTS
Three hundred eighty-three of 438 children (87%) aged 4 to 12 years with myopia of at least -1.0 diopter (D) originally randomized to receive atropine 0.05%, 0.025%, 0.01%, or placebo once daily in both eyes in the LAMP phase 1 study were continued in this extended trial (phase 2).
METHODS
Children in the placebo group (phase 1) were switched to receive 0.05% atropine from the beginning of the second-year follow-up, whereas those in the 0.05%, 0.025%, and 0.01% atropine groups continued with the same regimen. Cycloplegic refraction, axial length (AL), accommodation amplitude, photopic and mesopic pupil diameter, and best-corrected visual acuity were measured at 4-month intervals.
MAIN OUTCOME MEASURES
Changes in spherical equivalent (SE) and AL and their differences between groups.
RESULTS
Over the 2-year period, the mean SE progression was 0.55±0.86 D, 0.85±0.73 D, and 1.12±0.85 D in the 0.05%, 0.025%, and 0.01% atropine groups, respectively (P = 0.015, P < 0.001, and P = 0.02, respectively, for pairwise comparisons), with mean AL changes over 2 years of 0.39±0.35 mm, 0.50±0.33 mm, and 0.59±0.38 mm (P = 0.04, P < 0.001, and P = 0.10, respectively). Compared with the first year, the second-year efficacy of 0.05% and 0.025% atropine remained similar (P >0.1), but improved mildly in the 0.01% atropine group (P = 0.04). For the phase 1 placebo group, the myopia progression was reduced significantly after switching to 0.05% atropine (SE change, 0.18 D in second year vs. 0.82 D in first year [P < 0.001]; AL elongated 0.15 mm in second year vs. 0.43 mm in first year [P < 0.001]). Accommodation loss and change in pupil size in all concentrations remained similar to the first-year results and were well tolerated. Visual acuity and vision-related quality of life remained unaffected.
CONCLUSIONS
Over 2 years, the efficacy of 0.05% atropine observed was double that observed with 0.01% atropine, and it remained the optimal concentration among the studied atropine concentrations in slowing myopia progression.
Topics: Accommodation, Ocular; Administration, Topical; Atropine; Child; Child, Preschool; Disease Progression; Dose-Response Relationship, Drug; Double-Blind Method; Female; Follow-Up Studies; Humans; Male; Mydriatics; Myopia, Degenerative; Ophthalmic Solutions; Refraction, Ocular; Time Factors; Visual Acuity
PubMed: 32019700
DOI: 10.1016/j.ophtha.2019.12.011 -
Clinical & Experimental Optometry Jan 2020Modern methods of measuring the refractive state of the eye include wavefront sensors which make it possible to monitor both static and dynamic changes of the ocular... (Review)
Review
Modern methods of measuring the refractive state of the eye include wavefront sensors which make it possible to monitor both static and dynamic changes of the ocular wavefront while the eye observes a target positioned at different distances away from the eye. In addition to monitoring the ocular aberrations, wavefront refraction methods allow measurement of the accommodative response while viewing with the eye's habitual chromatic and monochromatic aberrations present, with these aberrations removed, and with specific aberrations added or removed. A large number of experiments describing the effects of accommodation on aberrations and vice versa are reviewed, pointing out the implications for fundamental questions related to the mechanism of accommodation.
Topics: Accommodation, Ocular; Corneal Wavefront Aberration; Humans; Refraction, Ocular; Visual Acuity
PubMed: 31284325
DOI: 10.1111/cxo.12938 -
Journal of Physiological Anthropology Jan 2024Myopia, commonly known as near-sightedness, has emerged as a global epidemic, impacting almost one in three individuals across the world. The increasing prevalence of... (Review)
Review
BACKGROUND
Myopia, commonly known as near-sightedness, has emerged as a global epidemic, impacting almost one in three individuals across the world. The increasing prevalence of myopia during early childhood has heightened the risk of developing high myopia and related sight-threatening eye conditions in adulthood. This surge in myopia rates, occurring within a relatively stable genetic framework, underscores the profound influence of environmental and lifestyle factors on this condition. In this comprehensive narrative review, we shed light on both established and potential environmental and lifestyle contributors that affect the development and progression of myopia.
MAIN BODY
Epidemiological and interventional research has consistently revealed a compelling connection between increased outdoor time and a decreased risk of myopia in children. This protective effect may primarily be attributed to exposure to the characteristics of natural light (i.e., sunlight) and the release of retinal dopamine. Conversely, irrespective of outdoor time, excessive engagement in near work can further worsen the onset of myopia. While the exact mechanisms behind this exacerbation are not fully comprehended, it appears to involve shifts in relative peripheral refraction, the overstimulation of accommodation, or a complex interplay of these factors, leading to issues like retinal image defocus, blur, and chromatic aberration. Other potential factors like the spatial frequency of the visual environment, circadian rhythm, sleep, nutrition, smoking, socio-economic status, and education have debatable independent influences on myopia development.
CONCLUSION
The environment exerts a significant influence on the development and progression of myopia. Improving the modifiable key environmental predictors like time spent outdoors and engagement in near work can prevent or slow the progression of myopia. The intricate connections between lifestyle and environmental factors often obscure research findings, making it challenging to disentangle their individual effects. This complexity underscores the necessity for prospective studies that employ objective assessments, such as quantifying light exposure and near work, among others. These studies are crucial for gaining a more comprehensive understanding of how various environmental factors can be modified to prevent or slow the progression of myopia.
Topics: Child, Preschool; Child; Humans; Prospective Studies; Myopia; Refraction, Ocular; Accommodation, Ocular; Circadian Rhythm
PubMed: 38297353
DOI: 10.1186/s40101-024-00354-7 -
Journal of Robotic Surgery Oct 2023Stereopsis may be an advantage of robotic surgery. Perceived robotic ergonomic advantages in visualisation include better exposure, three-dimensional vision, surgeon... (Review)
Review
Stereopsis may be an advantage of robotic surgery. Perceived robotic ergonomic advantages in visualisation include better exposure, three-dimensional vision, surgeon camera control, and line of sight screen location. Other ergonomic factors relating to visualisation include stereo-acuity, vergence-accommodation mismatch, visual-perception mismatch, visual-vestibular mismatch, visuospatial ability, visual fatigue, and visual feedback to compensate for lack of haptic feedback. Visual fatigue symptoms may be related to dry eye or accommodative/binocular vision stress. Digital eye strain can be measured by questionnaires and objective tests. Management options include treatment of dry eye, correction of refractive error, and management of accommodation and vergence anomalies. Experienced robotic surgeons can use visual cues like tissue deformation and surgical tool information as surrogates for haptic feedback.
Topics: Humans; Robotic Surgical Procedures; Asthenopia; Depth Perception; Accommodation, Ocular; Ergonomics
PubMed: 37204648
DOI: 10.1007/s11701-023-01618-7