-
Contact Lens & Anterior Eye : the... Aug 2020Overnight orthokeratology lenses are approved in countries all over the world for the temporary reduction in myopia, and recently, one lens design has received... (Review)
Review
Overnight orthokeratology lenses are approved in countries all over the world for the temporary reduction in myopia, and recently, one lens design has received regulatory approval for myopia control in Europe. The modern orthokeratology lens has a substantial history from its origins of attempting to flatten the corneal curvature with a spherical rigid contact lens to sophisticated gas permeable lenses, designed to reshape the cornea. These lenses are predominantly prescribed for children to slow myopia progression and limit axial elongation of the eye. This article reviews the peer-reviewed literature on the efficacy of orthokeratology for myopia control, sustainability after treatment is discontinued, and the safety concerns of overnight contact lens wear. Future avenues of research are discussed.
Topics: Child; Contact Lenses; Cornea; Corneal Topography; Europe; Humans; Myopia; Refraction, Ocular
PubMed: 32331970
DOI: 10.1016/j.clae.2020.03.018 -
Deutsches Arzteblatt International Oct 2022Millions of people in Germany wear contact lenses every day. Deficient contact lens hygiene can lead to corneal infection. Contact lens-associated keratitis usually has... (Review)
Review
BACKGROUND
Millions of people in Germany wear contact lenses every day. Deficient contact lens hygiene can lead to corneal infection. Contact lens-associated keratitis usually has a highly acute presentation and can cause long-term visual loss.
METHODS
This review is based on pertinent publications retrieved by a selective search in PubMed, as well as on relevant metaanalyses, Cochrane reviews, and reports by national and international health care authorities.
RESULTS
23-94% of contact lens wearers report associated discomfort and eye problems. The annual incidence of contact lens-associated keratitis is 2-4/10 000. It is due to bacteria in 90% of cases, and much less commonly to acanthamoebae and fungi. The pathogens generally arrive with the contact lens on the surface of the eye and can penetrate into the corneal tissue because the tear film under the lens is not swept away from the ocular surface by the eyelids, and corneal epithelial changes are often present as well. Corneal infiltration that is diagnosed early is often self-limited, but advanced bacterial infection usually requires intense topical antibiotic treatment. Some severe infections can only be eradicated by emergency corneal transplantation; this is the case in 20-30 % of fungal and acanthamoebic infections.
CONCLUSION
The wearing of contact lenses, particularly soft ones, is associated with a risk of microbial keratitis if proper contact lens hygiene is not exercised. Contact lens-associated keratitis very rarely causes permanent damage to eyesight (0.6 cases per 10 000 contact lens wearers per year). The use of contact lenses always calls for meticulous care.
Topics: Humans; Corneal Ulcer; Keratitis; Contact Lenses; Cornea; Corneal Diseases
PubMed: 35912449
DOI: 10.3238/arztebl.m2022.0281 -
Indian Journal of Ophthalmology Apr 2023Dry eye disease (DED) is prevalent in all age groups and is known to cause chronic ocular discomfort and pain, and greatly affects the quality of life. Patients with... (Review)
Review
Dry eye disease (DED) is prevalent in all age groups and is known to cause chronic ocular discomfort and pain, and greatly affects the quality of life. Patients with ocular surface disease (OSD) may also have reduced tear secretion due to lacrimal gland damage, thus leading to aqueous deficient DED. Even with conventional management modalities such as lubricating eyedrops, topical corticosteroids, autologous serum eyedrops, or punctal plugs, many patients continue to suffer from debilitating symptoms. Contact lenses are increasingly being used in OSD providing surface hydration, protection from environmental insults, mechanical damage from abnormal lids, and as a modality for constant drug delivery to the ocular surface. This review describes the role of soft lenses and rigid gas-permeable scleral lenses in the management of DED associated with OSD. The efficacy of contact lenses, lens selection, and optimal lens fit are reviewed for specific indications.
Topics: Humans; Quality of Life; Dry Eye Syndromes; Contact Lenses; Lacrimal Apparatus; Ophthalmic Solutions
PubMed: 37026246
DOI: 10.4103/IJO.IJO_2778_22 -
Clinical & Experimental Optometry Sep 2017The prevalence of myopia has been steadily rising, with 28 per cent of the global population said to be affected in 2010 and to rise to affect nearly 50 per cent by... (Review)
Review
The prevalence of myopia has been steadily rising, with 28 per cent of the global population said to be affected in 2010 and to rise to affect nearly 50 per cent by 2050. Increasing levels of myopia increase the risk of vision impairment and in particular, high myopia is associated with the risk of serious and permanent visual disability due to associated sight-threatening complications. To stem the burden associated with higher levels of myopia, there are efforts to slow the progression of myopia, and several optical and pharmaceutical strategies have been found useful in slowing myopia to varying degrees. More recently, numerous multifocal soft contact lenses and extended depth of focus soft contact lenses (collectively referred to as myopia control contact lenses) were found effective in slowing myopia. As opposed to overnight orthokeratology, myopia control contact lenses are worn during the day and the hypotheses proposed to explain the efficacy of these lenses are generally based on the premise that the stimulus for eye growth is a defocused retinal image with hyperopic blur either centrally or peripherally. Although the individual power profiles of the lenses vary, the contact lens generally incorporates 'positive power' to reduce the hyperopic blur and/or impose myopic defocus or in the case of the extended depth of focus lens, has a power profile designed to optimise retinal image quality for points on or in front of the retina. The use of soft contact lenses as a platform for myopia control offers an exciting and effective avenue to manage myopia but there is a need for further research on issues such as the mechanism underlying control of myopia, improving efficacy with lenses, and understanding rebound on discontinuation. More significantly, although contact lenses are generally safe and improve quality of life in older children, one of the major challenges for improved uptake and acceptance of contact lenses centres on the perceived risk of complications with lens wear. This issue needs to be addressed.
Topics: Contact Lenses; Contact Lenses, Hydrophilic; Disease Progression; Eyeglasses; Humans; Myopia
PubMed: 28752898
DOI: 10.1111/cxo.12584 -
Eye (London, England) Dec 2020Our aim is to review current and significant articles on contact lens wear in keratoconus patients. A comprehensive literature search of PubMed was performed for the... (Review)
Review
Our aim is to review current and significant articles on contact lens wear in keratoconus patients. A comprehensive literature search of PubMed was performed for the following topics on contact lens wear in keratoconus patients: (1) characteristics of contact lens wearers, (2) safety and efficacy, (3) complications, (4) fitting techniques, (5) contact lens wear after procedures/surgeries, (6) patient satisfaction. A total of 104 studies were finally selected and reviewed. Gas permeable (GP) lens wear provided significantly better vision than glasses. Special cone design lenses had better patient comfort levels though there was no difference in best corrected visual acuity among the GP lenses. Soft lenses showed good efficacy for the treatment of mild-to-moderate keratoconus with newer designs improving visual performance such as customised hydrogel and novel pinhole lenses. Scleral and hybrid lenses provide good visual acuity and comfort for keratoconic patients previously intolerant to RGP lenses. RGP lens wear post-cross linking (CXL) is relatively well-tolerated. Contact lenses may still be required post intrastromal corneal ring procedures and post keratoplasty. Scheimpflug imaging and anterior segment optical coherent tomography (ASOCT) are useful in contact lens fitting. Computerized contact lens fitting techniques could reduce the chair time of lens fitting as well as improve comfort and visual performance. Contact lenses play an important role in the visual rehabilitation of keratoconus patients. New contact lens designs and materials have significantly expanded the available fitting options for keratoconus patients. Imaging technology can be utilized to guide contact lens fitting.
Topics: Contact Lenses; Corneal Topography; Humans; Keratoconus; Prosthesis Fitting; Retrospective Studies; Sclera; Visual Acuity
PubMed: 32641797
DOI: 10.1038/s41433-020-1065-z -
Progress in Retinal and Eye Research May 2020Contact lenses represent a widely utilized form of vision correction with more than 140 million wearers worldwide. Although generally well-tolerated, contact lenses can... (Review)
Review
Contact lenses represent a widely utilized form of vision correction with more than 140 million wearers worldwide. Although generally well-tolerated, contact lenses can cause corneal infection (microbial keratitis), with an approximate annualized incidence ranging from ~2 to ~20 cases per 10,000 wearers, and sometimes resulting in permanent vision loss. Research suggests that the pathogenesis of contact lens-associated microbial keratitis is complex and multifactorial, likely requiring multiple conspiring factors that compromise the intrinsic resistance of a healthy cornea to infection. Here, we outline our perspective of the mechanisms by which contact lens wear sometimes renders the cornea susceptible to infection, focusing primarily on our own research efforts during the past three decades. This has included studies of host factors underlying the constitutive barrier function of the healthy cornea, its response to bacterial challenge when intrinsic resistance is not compromised, pathogen virulence mechanisms, and the effects of contact lens wear that alter the outcome of host-microbe interactions. For almost all of this work, we have utilized the bacterium Pseudomonas aeruginosa because it is the leading cause of lens-related microbial keratitis. While not yet common among corneal isolates, clinical isolates of P. aeruginosa have emerged that are resistant to virtually all currently available antibiotics, leading the United States CDC (Centers for Disease Control) to add P. aeruginosa to its list of most serious threats. Compounding this concern, the development of advanced contact lenses for biosensing and augmented reality, together with the escalating incidence of myopia, could portent an epidemic of vision-threatening corneal infections in the future. Thankfully, technological advances in genomics, proteomics, metabolomics and imaging combined with emerging models of contact lens-associated P. aeruginosa infection hold promise for solving the problem - and possibly life-threatening infections impacting other tissues.
Topics: Anti-Bacterial Agents; Bacteria; Contact Lenses; Cornea; Eye Infections, Bacterial; Humans; Keratitis; Prosthesis-Related Infections
PubMed: 31756497
DOI: 10.1016/j.preteyeres.2019.100804 -
Clinical & Experimental Optometry Jan 2018
Topics: Conjunctivitis; Contact Lenses, Hydrophilic; Corneal Edema; Humans; Inflammation
PubMed: 29235184
DOI: 10.1111/cxo.12629 -
Experimental Eye Research Jan 2021Acanthamoeba keratitis (AK) is a rare protozoal infection of the cornea. At least eight species of Acanthamoeba are known to cause this sight-threatening disease of the... (Review)
Review
Acanthamoeba keratitis (AK) is a rare protozoal infection of the cornea. At least eight species of Acanthamoeba are known to cause this sight-threatening disease of the ocular surface. Acanthamoeba spp. exist in a wide array of niches ranging from thermal springs to under ice and every conceivable habitat in between. Contact lens wear is the leading risk factor for AK and is practiced by over 30 million individuals in the United States, yet the incidence of AK is less than 33 cases per one million contact lens wearers. Serological studies have reported that 90%-100% of individuals with no history of AK possess antibodies specific for Acanthamoeba antigens indicating that exposure to this organism is commonplace, yet disease is remarkably rare. Animal studies have shed light on the pathobiology and immunobiology of AK and indicate that a constellation of factors including the ocular surface microbiome and the microbiome of Acanthamoeba itself contribute to the pathogenesis of AK. Interesting, secretory antibodies produced by the adaptive immune response can prevent the initiation of corneal infection, but once Acanthamoeba trophozoites breach the corneal epithelium the adaptive immune system is helpless in altering the course of AK. It has been almost 50 years since AK was first described, yet many questions remain unanswered about this curious and enigmatic disease of the ocular surface.
Topics: Acanthamoeba; Acanthamoeba Keratitis; Animals; Antibodies, Protozoan; Contact Lenses; Cornea; Eye Infections, Parasitic; Humans; Risk Factors
PubMed: 33221372
DOI: 10.1016/j.exer.2020.108365 -
Asia-Pacific Journal of Ophthalmology... Dec 2020Contact lens wear is one of the relevant risk factors for dry eye, and the coexistence of dry eye poses a serious challenge in patients wearing contact lenses. The Tear... (Review)
Review
Contact lens wear is one of the relevant risk factors for dry eye, and the coexistence of dry eye poses a serious challenge in patients wearing contact lenses. The Tear Film and Ocular Surface Society Workshop addressed issues around the topic of discomfort in contact lens wear, which is a major cause for discontinuation of contact lens wear, and termed this condition as contact lens discomfort. With the rapid advances in contact lens technology and pharmacological agents and deeper understanding of this field, updating the "new normal" beyond what is known as standard is essential. This review aims to summarize the latest topics in contact lens and dry eye that would be useful for clinicians and contact lens practitioners.
Topics: Contact Lenses, Hydrophilic; Dry Eye Syndromes; Humans; Tears
PubMed: 33284229
DOI: 10.1097/APO.0000000000000329 -
Clinical & Experimental Optometry Apr 2022Contact lens prescribing data serve as a benchmark for eye care clinicians in assessing their own prescribing patterns and provide useful contextual information for...
CLINICAL RELEVANCE
Contact lens prescribing data serve as a benchmark for eye care clinicians in assessing their own prescribing patterns and provide useful contextual information for researchers and the contact lens industry.
PURPOSE
To document global trends in contact lens prescribing during the first two decades of this century.
METHODS
A longitudinal survey of contact lens prescribing was conducted by asking contact lens practitioners to provide 11 items of information from 10 consecutive contact lens fits between January and March each year from 1996 to 2020, inclusive.
RESULTS
Data relating to 406,859 contact lens fits were collected from 71 countries between 1996 and 2020, generating 4.5 million data points. Demographic analysis for 61 nations returning ≥100 fits demonstrated that a majority of lenses (65-70%) were fitted to females. The average age of lens wearers was 30.8 ± 13.9 years for males and 32.5 ± 14.3 years for females. Trend analysis of 20 countries returning prescribing data for ≥13 years between 2000 and 2020 revealed the following: increase in the age of lens wearers; dramatic rise in the extent of fitting silicone hydrogel and daily disposable lenses; increased fitting of soft toric and multifocal lenses; increasing proportion of rigid lens fits in specialist (non-spherical) designs; incomplete provision of near contact lens corrections for contact lens wearing presbyopes; ongoing low levels of extended wear fits; and almost exclusive use of multi-purpose care systems. Daily disposable lenses were used for both full-time and part-time wear, whereas rigid and soft reusable lenses were primarily worn full time.
CONCLUSIONS
The evolution of international contact lens fitting over the first two decades of this century is documented. The data presented here may assist all stakeholders in advancing contact lens clinical practice, informing contact lens research, and guiding contact lens manufacturers.
Topics: Adolescent; Adult; Contact Lenses; Contact Lenses, Hydrophilic; Female; Humans; Male; Optometry; Prescriptions; Silicones; Surveys and Questionnaires; Young Adult
PubMed: 35184672
DOI: 10.1080/08164622.2022.2033604