Optometry and vision science : official publication of the American Academy of Optometry
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Randomized Controlled Trial
Myopia Control with Bifocal Contact Lenses: A Randomized Clinical Trial.
Most studies have reported only minimal reductions in myopia progression with bifocal or progressive multifocal spectacles, although somewhat larger, although mostly still clinically insignificant, effects have been reported in children with nearpoint esophoria and/or accommodative dysfunctions. The CONTROL study was a 1-year, prospective, randomized, clinical trial of bifocal contact lenses for control of myopia in children with eso fixation disparities at near. ⋯ The distance center bifocal contact lenses tested in this study achieved greater control over myopia progression and axial elongation (>70%) compared with most published results with multifocal spectacles. Further studies are warranted to identify the critical factors and mechanisms underlying this myopia control effect.
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To illustrate that corneal neuralgia may be the basis for refractory dry eye syndrome after laser-assisted in situ keratomileusis (LASIK). ⋯ Patients with persistent dry eye symptoms out of proportion to clinical signs after LASIK have a syndrome that may best be classified as corneal neuralgia. In vivo confocal microscopy can be informative as to the neuropathic basis of this condition. In keeping with current understanding of complex regional pain syndrome, early multimodal treatment directed toward reducing peripheral nociceptive signaling is warranted to avoid subsequent centralization and persistence of pain. Distinguishing this syndrome from typical post-LASIK dry eye remains a challenge.
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A panel of experts was invited to discuss the following questions: Why does the prevalence of dry eye disease (DED) appear to be increasing? Are you satisfied with the current definition and classification of DED-aqueous deficiency versus evaporative dry eye? Beyond the innate human factors (e.g., genetics), what external factors might contribute to DED? What areas related to DED need to be more fully understood? In examining a patient complaining of dry eye, what is your strategy (e.g., tests, questionnaire)? What is your strategy in unraveling the root cause of a patient's dry eye symptoms that may be shared by many anterior segment diseases? What are the two or three most common errors made by clinicians in diagnosing DED? Why do contact lens (CL) patients complain of dry eye while wearing lenses but not when not wearing lenses? What areas related to CL discomfort need to be more fully understood? What is your most effective strategy for minimizing CL discomfort? With current advances in biotechnology in dry eye diagnostics and management tools, do you think our clinicians are better prepared to diagnose and treat this chronic condition than they were 5 or 10 years ago? Do you foresee any of these new point-of-care tests becoming standard clinical tests in ocular surface evaluation? What treatments are effective for obstructed Meibomian glands secondary to lid margin keratinization? What level of DED would prevent you from recommending an elected ophthalmic surgery? What strategy do you use to help your patients comply with the recommended home therapies? How do you best manage patients whose severity of dry eye symptoms does not necessarily match clinical test results, especially in cases of ocular surface neuropathy? Where do you see dry eye diagnosis and treatment in 10 years or more?
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A head-centric disparity model of anomalous binocular correspondence (ABC) in strabismus provides a framework that captures several associated perceptual-motor characteristics that are unexplained by the retino-centric model (anomalous retinal correspondence) of Von Graefe and Burian. The head-centric model elaborates on the anomalous-projection model of Verhoeff and Brock, originally described by Wells, late in the 18th century, which proposes that three-dimensional space perception is based on information obtained separately from the two eyes in ABC, without binocular retinal correspondence. Binocular parallax angles formed by the two eyes' monocular head-centric directions provide sufficient information to estimate distance but not enough to stimulate diplopia without a reference for zero disparity. ⋯ In ABC, the subjective-squint angle is unaffected by registered vergence movements. Binocular sensory fusion is obtained via the head-centric model by adjusting the diameter of the head-centric horopter, independent of the vergence angle, from the fixation distance to the distance of another reference point. By altering the reference viewing distance for zero disparity, the sign and magnitude of disparity stimuli for fusion and diplopia are changed, thereby enabling the perception of a fused fixation target and the appreciation of physiological diplopia in strabismus.
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The previous literature on Bland-Altman analysis only describes approximate methods for calculating confidence intervals for 95% limits of agreement (LoAs). This article describes exact methods for calculating such confidence intervals based on the assumption that differences in measurement pairs are normally distributed. ⋯ Exact confidence intervals for LoAs can differ considerably from the Bland and Altman approximate method, especially for sample sizes that are not large. There are better, more precise methods for calculating confidence intervals for LoAs than the Bland and Altman approximate method, although even an approximate calculation of confidence intervals for LoAs is likely to be better than none at all. Reporting confidence limits for LoAs considered as a pair is appropriate for most situations; however, there may be circumstances where it is appropriate to report confidence limits for LoAs considered individually.