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Fulltext Spontaneous repositioning of posterior chamber intraocular lens: a mere coincidence?

Wern-Yih C, Jan-Bond C, Sudha M, Norlelawati A, Shatriah I

Arq Bras Oftalmol, 2020 08;83(4):329-331.
PMID: 32756777 DOI: 10.5935/0004-2749.20200054

Despite the recent developments in modern cataract surgery and the application of a vast array of new devices and machines, late in-the-bag intraocular lens dislocation remains a devastating, albeit rare, complication. Various nonsurgical and surgical techniques have been used to manage this complication. We report a case of spontaneous repositioning in the left eye of an anteriorly subluxated in-the-bag intraocular lens. The spontaneous repositioning may have been caused by antagonistic effects related to the topical administration of brimonidine and prednisolone. The dislocation was treated without aggressive manipulation or surgical intervention.

Matched MeSH terms: Lenses, Intraocular*
Targeting cyst wall is an effective strategy in improving the efficacy of marketed contact lens disinfecting solutions against Acanthamoeba castellanii cysts

Abjani F, Khan NA, Yousuf FA, Siddiqui R

Cont Lens Anterior Eye, 2016 Jun;39(3):239-43.
PMID: 26675112 DOI: 10.1016/j.clae.2015.11.004

Acanthamoeba cysts are highly resistant to contact lens disinfecting solutions. Acanthamoeba cyst wall is partially made of 1,4 β-glucan (i.e., cellulose) and other complex polysaccharides making it a hardy shell that protects the resident amoeba. Here, we hypothesize that targeting the cyst wall structure in addition to antiamoebic compound would improve the efficacy of marketed contact lens disinfecting solutions. Using chlorhexidine as an antiamoebic compound and cellulase enzyme to disrupt cyst wall structure, the findings revealed that combination of both agents abolished viability of Acanthamoeba castellanii cysts and trophozoites. When tested alone, none of the agents nor contact lens disinfecting solutions completely destroyed A. castellanii cysts and trophozoites. The absence of cyst wall-degrading enzymes in marketed contact lens disinfecting solutions render them ineffective against Acanthamoeba cysts. It is concluded that the addition of cyst wall degrading molecules in contact lens disinfecting solutions will enhance their efficacy in decreasing the incidence of Acanthamoeba effectively.

Matched MeSH terms: Contact Lenses/adverse effects; Contact Lenses/parasitology*
Development of anti-acanthamoebic approaches

Mungroo MR, Tong T, Khan NA, Anuar TS, Maciver SK, Siddiqui R

Int Microbiol, 2021 Aug;24(3):363-371.
PMID: 33754231 DOI: 10.1007/s10123-021-00171-3

Acanthamoeba keratitis is a sight-endangering eye infection, and causative organism Acanthamoeba presents a significant concern to public health, given escalation of contact lens wearers. Contemporary therapy is burdensome, necessitating prompt diagnosis and aggressive treatment. None of the contact lens disinfectants (local and international) can eradicate Acanthamoeba effectively. Using a range of compounds targeting cellulose, ion channels, and biochemical pathways, we employed bioassay-guided testing to determine their anti-amoebic effects. The results indicated that acarbose, indaziflam, terbuthylazine, glimepiride, inositol, vildagliptin and repaglinide showed anti-amoebic effects. Compounds showed minimal toxicity on human cells. Therefore, effects of the evaluated compounds after conjugation with nanoparticles should certainly be the subject of future studies and will likely lead to promising leads for potential applications.

Matched MeSH terms: Contact Lenses/adverse effects; Contact Lenses/parasitology*
Applications of photodynamic therapy in keratitis

Anwar A, Khan NA, Alharbi AM, Alhazmi A, Siddiqui R

Int Ophthalmol, 2024 Mar 15;44(1):140.
PMID: 38491335 DOI: 10.1007/s10792-024-03062-4

Keratitis is corneal inflammatory disease which may be caused by several reason such as an injury, allergy, as well as a microbial infection. Besides these, overexposure to ultraviolet light and unhygienic practice of contact lenses are also associated with keratitis. Based on the cause of keratitis, different lines of treatments are recommended. Photodynamic therapy is a promising approach that utilizes light activated compounds to instigate either killing or healing mechanism to treat various diseases including both communicable and non-communicable diseases. This review focuses on clinically-important patent applications and the recent literature for the use of photodynamic therapy against keratitis.

Matched MeSH terms: Contact Lenses*
Refractive outcomes comparison between the Lenstar LS 900® optical biometry and immersion A-scan ultrasound

Naicker P, Sundralingam S, Peyman M, Juana A, Mohamad NF, Win MM, et al.

Int Ophthalmol, 2015 Aug;35(4):459-66.
PMID: 25024102 DOI: 10.1007/s10792-014-9970-4

To determine the accuracy of intraocular lens (IOL) calculations in eyes undergoing phacoemulsification cataract surgery with IOL implantation using immersion A-scan ultrasound (US) and Lenstar LS 900(®) biometry. In this prospective study, 200 eyes of 200 patients were randomized to undergo either Lenstar LS 900(®) or immersion A-scan US biometry to determine the IOL dioptric power prior to phacoemulsification cataract surgery. Post-operative refractive outcomes of these two groups of patients were compared. The result showed no significant difference between the target spherical equivalent (SE) and the post-operative SE value by the Lenstar LS 900(®) (p value = 0.632) or immersion A-scan US biometry (p value = 0.438) devices. The magnitude of difference between the two biometric devices were not significantly different (p value = 0.868). There was no significant difference in the predicted post-operative refractive outcome between immersion A-scan US biometry and Lenstar LS 900(®). Based on the results, the immersion A-scan US technique is as accurate as Lenstar LS 900(®) in the hands of an experienced operator.

Matched MeSH terms: Lenses, Intraocular*
Fulltext Agreement analysis of LENSTAR with other techniques of biometry

Jasvinder S, Khang TF, Sarinder KK, Loo VP, Subrayan V

Eye (Lond), 2011 Jun;25(6):717-24.
PMID: 21394115 DOI: 10.1038/eye.2011.28

To assess the agreement of the optical low-coherence reflectometry (OLCR) device LENSTAR LS900 with partial coherence interferometry (PCI) device IOLMaster and applanation and immersion ultrasound biometry.

Matched MeSH terms: Lenses, Intraocular*
Fulltext Intraocular lens implant

Sukumaran K

Med J Malaysia, 1983 Dec;38(4):272-4.
PMID: 6599981
Matched MeSH terms: Lenses, Intraocular*
A systematic review of phacoemulsification cataract surgery in virtual reality simulators

Lam CK, Sundaraj K, Sulaiman MN

Medicina (Kaunas), 2013;49(1):1-8.
PMID: 23652710

The aim of this study was to review the capability of virtual reality simulators in the application of phacoemulsification cataract surgery training. Our review included the scientific publications on cataract surgery simulators that had been developed by different groups of researchers along with commercialized surgical training products, such as EYESI® and PhacoVision®. The review covers the simulation of the main cataract surgery procedures, i.e., corneal incision, capsulorrhexis, phacosculpting, and intraocular lens implantation in various virtual reality surgery simulators. Haptics realism and visual realism of the procedures are the main elements in imitating the actual surgical environment. The involvement of ophthalmology in research on virtual reality since the early 1990s has made a great impact on the development of surgical simulators. Most of the latest cataract surgery training systems are able to offer high fidelity in visual feedback and haptics feedback, but visual realism, such as the rotational movements of an eyeball with response to the force applied by surgical instruments, is still lacking in some of them. The assessment of the surgical tasks carried out on the simulators showed a significant difference in the performance before and after the training.

Matched MeSH terms: Lenses, Intraocular
Contact lens-related infectious keratitis in Malaysia

Reddy SC, Tajunisah I

Ann Ophthalmol (Skokie), 2008;40(1):39-44.
PMID: 18556981

Fifty-six contact lens-related corneal ulcers (central in 32; hypopyon in 24 and stromal abscess in 6) were studied. Culture was positive in 78.9%. Corneal ulcers healed with intense antibiotic therapy in nearly all patients. Increased awareness of lens care/disinfection and frequent replacement of storage cases and solution, and early detection of pathogens and intensive appropriate antibiotic therapy are key points in management.

Matched MeSH terms: Contact Lenses/microbiology*
Fulltext Manufacture of Contact Lens of Nanoparticle-Doped Polymer Complemented with ZEMAX

Shaker LM, Al-Amiery AA, Kadhum AAH, Takriff MS

Nanomaterials (Basel), 2020 Oct 15;10(10).
PMID: 33076278 DOI: 10.3390/nano10102028

Many people suffer from myopia or hyperopia due to the refractive errors of the cornea all over the world. The use of high refractive index (RI), Abbe number (νd), and visible light transmittance (T%) polymeric contact lenses (CLs) holds great promise in vision error treatment as an alternative solution to the irreversible laser-assisted in situ keratomileusis (LASIK) surgery. Titanium dioxide nanoparticles (TiO2 NPs) have been suggested as a good candidate to rise the RI and maintain high transparency of a poly(methyl methacrylate) (PMMA)-TiO2 nanocomposite. This work includes a preparation of TiO2 NPs using the sol gel method as well as a synthesis of pure PMMA by free radical polarization and PMMA-TiO2 CLs using a cast molding method of 0.005 and 0.01 w/v concentrations and a study of their effect on the aberrated human eye. ZEMAX optical design software was used for eye modeling based on the Liou and Brennan eye model and then the pure and doped CLs were applied. Ocular performance was evaluated by modulation transfer function (MTF), spot diagram, and image simulation. The used criteria show that the best vision correction was obtained by the CL of higher doping content (p < 0.0001) and that the generated spherical and chromatic aberrations in the eye had been reduced.

Matched MeSH terms: Contact Lenses
Fulltext Retained intraocular foreign bodies and visual prognosis

Tan PL

Med J Malaysia, 1980 Sep;35(1):58-60.
PMID: 7254000

3 cases of perforating injury with retention of intra-ocular foreign body are presented. Their clinical presentation, management and final visual results are discussed. Despite the generally poor prognosis associated with these injuries, some cases surprisingly have good visual results.

Matched MeSH terms: Contact Lenses
Fulltext Patterns of Use and Knowledge about Contact Lens Wear amongst Teenagers in Rural Areas in Malaysia

Mohd-Ali B, Tan XL

Int J Environ Res Public Health, 2019 12 17;16(24).
PMID: 31861174 DOI: 10.3390/ijerph16245161

BACKGROUND: Contact lenses (CLs) are more popular than spectacles for vision correction amongst the youth. Knowledge about the risks of wearing CLs is critical especially for those with poor access to public health education. This study investigates the patterns of use and level of knowledge about CL wear amongst teenagers living in rural areas in Selangor, Malaysia using a set of validated questionnaires.
METHODS: A total of 8500 self-administered questionnaires were distributed in eight selected secondary schools. The results were analysed using descriptive statistics.
RESULTS: A total of 2474 (29%) completed questionnaires were collected. The mean age of the respondents was 14.8 ± 1.5 years, and approximately 7.2% were CL wearers. The majority of the wearers were females (76.0%) and wore soft CLs (92.2%). Cosmetic purposes (58.1%) and comfort (24.6%) were the main reasons for wearing CLs. Many of the respondents purchased their lenses from optical shops (50.1%) and beauty accessory shops (15.6%), and approximately 10% did not disinfect their lenses properly. Regarding knowledge about CL care, approximately 56% of the respondents responded correctly.
CONCLUSION: Half of the respondents do not have sufficient knowledge about the risks of wearing CLs. Thus, aggressive public health education aimed at teenagers is needed to prevent improper CL usage.

Matched MeSH terms: Contact Lenses*
Fulltext A survey of optometric contact lens prescribing in Malaysia

Norhani Mohidin, Tee, Lee Fung

Jurnal Sains Kesihatan Malaysia, 2009;7(2):59-72.
MyJurnal

This survey represents an initial examination of contact lens practice in Malaysia. It is based on a questionnaire that was sent to selected members of the Association of the Malaysian Optometrists to survey the prescribing habits of g contact lenses and care products. Questions included types of lenses prescribed, care systems frequently recommended and types of complications seen. Optometrists in Malaysia prescribed an average of 90 new pairs of contact lenses per year. Soft lenses made up 84% of the prescription followed by 14% of rigid gas permeable lenses and 1.5% of polymethymethacrylate lenses. Disposable/frequent replacement lenses accounted for 60% of the soft lenses prescribed. The most commonly prescribed disinfecting system was chemical disinfection. The most common complication seen during aftercare consultation was dry eye-related problems.

Matched MeSH terms: Contact Lenses
Analysis of coupling efficiency on hemispherical fiber lens by method of lines

Lambak Z, Abdul Rahman F, Mokhtar MR, Tengku IA

Opt Express, 2009 Feb 16;17(4):2926-37.
PMID: 19219196

The method of lines (MoL) has been developed to study coupling efficiency on hemispherical lens. In this paper, the physical shape of the lens is approximated by cascading a number of straight waveguide segments. The perfectly matched layer (PML) is applied as an absorber for the MoL to reduce numerical reflection in the simulation region. Analysis is done by calculating coupling efficiency at the plane of integration where the coupling efficiency is an overlap integral between laser diode field and fiber field. The result of coupling efficiency in this analysis is compared to the experiment and ABCD matrix. It is found that MoL gives good result accuracy.

Matched MeSH terms: Lenses*
Underwater DVI: Simple fingerprint technique for positive identification

Khoo LS, Hasmi AH, Mahmood MS, Vanezis P

Forensic Sci Int, 2016 Sep;266:e4-e9.
PMID: 27567043 DOI: 10.1016/j.forsciint.2016.08.019

An underwater disaster can be declared when a maritime accident occurred or when an aircraft is plunged into water area, be it ocean, sea or river. Nevertheless, handling of human remains in an underwater recovery operation is often a difficult and demanding task as working conditions may be challenging with poor to no visibility, location of remains at considerable depths and associated hazards from surrounding water. A case of the recent helicopter crash, into a famous river in Sarawak, domiciled by huge crocodiles, is discussed in this paper. Search and recovery team as well as the combat divers from the Special Elite Troop Commando, known as VAT 69, were deployed to the scene to perform the underwater recovery to search for all the victims on board involving five Malaysians with a pilot of Philippines nationality. This paper highlights the limitations and challenges faced during the underwater search and recovery. All the bodies recovered were in moderate decomposition stage with crushed injuries and mutilated face and body. A simple and conventional fingerprint technique were used to record the fingerprint. The prints impressions were later photographed using a smartphone and transferred back to the RMP headquarters in Kuala Lumpur for fingerprint match by using WhatsApp Messenger, a phone application. All the first five victims were identified within an average of 10min. The last victim recovered was the pilot. For foreign nationals, the Immigration Department of Malaysia will record the prints of both index fingers only. The lifting of the fingerprint of the last victim was the most challenging in which only one index finger left that can be used for comparison. A few techniques were attempted using the black printer's ink, glass and tape techniques for the last victim. Subsequently, images of the prints impression were taken using the same smartphone with additional macro lens attached to it to enhance the resolution. The images were transferred to the RMP headquarters through WhatsApp Messenger. The prints were confirmed to be the pilot 20min later.

Matched MeSH terms: Lenses
Fulltext Intralenticular matchstick in a toddler: a rare presentation of penetrating ocular injury from a toy gun

Royan, Jeyarine, Teo, Khairy Shamel Sonny, Vengadasalam, Selva Raja

Journal of Biomedical and Clinical Sciences, 2018;3(1):15-18.
MyJurnal

To report on a rare case of an intralenticular foreign body which
demonstrates that use of a spring-powered airsoft gun can result in a severe
ocular injury. A 2-year-old male presented following a trauma to the left eye.
The trauma was caused by a wooden matchstick from a spring-powered airsoft
gun being shot into his eye. On examination, there was a shallow anterior
chamber with a full thickness corneal laceration, with fragmented matchstick
pieces embedded in the cornea and in the lens. The corneal foreign bodies
were removed, corneal laceration wound sutured and lensectomy done. There
were no post-operative complications, and the cornea wound healed with a
scar. A few months later, he underwent a successful secondary intraocular lens
implantation surgery with an iris claw lens. Airsoft guns are easily available to
children who are unaware of its dangers. It can cause significant ocular
morbidity despite successful surgical treatment of the injury.

Matched MeSH terms: Lenses, Intraocular
Fulltext Spontaneous dislocation of intraocular lens as a late complication of uncomplicated cataract surgery: a case series

Lam HH, Visvaraja S

Clin Exp Optom, 2012 Jan;95(1):99-102.
PMID: 21954950 DOI: 10.1111/j.1444-0938.2011.00640.x

Five patients having uncomplicated phacoemulsification were implanted with CT-Asphina 603P intraocular lenses into the capsular bag. After a few months, three of the patients had haptic flexion anterior to the optic despite minimal capsular fibrosis. One patient had spontaneous dislocation of the intraocular lens into the anterior chamber with only minimal capsular fibrosis. Another patient had one haptic dislocated out of the bag. Late intraocular lens dislocation is also seen in newly designed preloaded intraocular lenses despite the absence of significant capsular fibrosis. Haptic-optic junction design and intraocular lens material play important roles in such complication. A slightly large capsulorhexis might be a deterrent for implantation of this intraocular lens.

Matched MeSH terms: Lenses, Intraocular*
Fulltext Management and treatment of contact lens-related Pseudomonas keratitis

Willcox MD

Clin Ophthalmol, 2012;6:919-24.
PMID: 22791973 DOI: 10.2147/OPTH.S25168

Pubmed and Medline were searched for articles referring to Pseudomonas keratitis between the years 2007 and 2012 to obtain an overview of the current state of this disease. Keyword searches used the terms "Pseudomonas" + "Keratitis" limit to "2007-2012", and ["Ulcerative" or "Microbial"] + "Keratitis" + "Contact lenses" limit to "2007-2012". These articles were then reviewed for information on the percentage of microbial keratitis cases associated with contact lens wear, the frequency of Pseudomonas sp. as a causative agent of microbial keratitis around the world, the most common therapies to treat Pseudomonas keratitis, and the sensitivity of isolates of Pseudomonas to commonly prescribed antibiotics. The percentage of microbial keratitis associated with contact lens wear ranged from 0% in a study from Nepal to 54.5% from Japan. These differences may be due in part to different frequencies of contact lens wear. The frequency of Pseudomonas sp. as a causative agent of keratitis ranged from 1% in Japan to over 50% in studies from India, Malaysia, and Thailand. The most commonly reported agents used to treat Pseudomonas keratitis were either aminoglycoside (usually gentamicin) fortified with a cephalosporin, or monotherapy with a fluoroquinolone (usually ciprofloxacin). In most geographical areas, most strains of Pseudomonas sp. (≥95%) were sensitive to ciprofloxacin, but reports from India, Nigeria, and Thailand reported sensitivity to this antibiotic and similar fluoroquinolones of between 76% and 90%.

Matched MeSH terms: Contact Lenses
Fulltext Differences in Perspectives of Medical Device Adverse Events: Observational Results in Training Program Using Virtual Cases

Yoon C, Nam KC, Lee YK, Kang Y, Choi SJ, Shin HM, et al.

J Korean Med Sci, 2019 Oct 14;34(39):e255.
PMID: 31602825 DOI: 10.3346/jkms.2019.34.e255

BACKGROUND: Medical device adverse event reporting is an essential activity for mitigating device-related risks. Reporting of adverse events can be done by anyone like healthcare workers, patients, and others. However, for an individual to determine the reporting, he or she should recognize the current situation as an adverse event. The objective of this report is to share observed individual differences in the perception of a medical device adverse event, which may affect the judgment and the reporting of adverse events.
METHODS: We trained twenty-three participants from twelve Asia-Pacific Economic Cooperation (APEC) member economies about international guidelines for medical device vigilance. We developed and used six virtual cases and six questions. We divided participants into six groups and compared their opinions. We also surveyed the country's opinion to investigate the beginning point of 'patient use'. The phases of 'patient use' are divided into: 1) inspecting, 2) preparing, and 3) applying medical device.
RESULTS: As for the question on the beginning point of 'patient use,' 28.6%, 35.7%, and 35.7% of participants provided answers regarding the first, second, and third phases, respectively. In training for applying international guidelines to virtual cases, only one of the six questions reached a consensus between the two groups in all six virtual cases. For the other five questions, different judgments were given in at least two groups.
CONCLUSION: From training courses using virtual cases, we found that there was no consensus on 'patient use' point of view of medical devices. There was a significant difference in applying definitions of adverse events written in guidelines regarding the medical device associated incidents. Our results point out that international harmonization effort is needed not only to harmonize differences in regulations between countries but also to overcome diversity in perspectives existing at the site of medical device use.

Matched MeSH terms: Contact Lenses/adverse effects
Fulltext Sensitivity of Acanthamoeba cyst to antimicrobial agents

Noradilah, S. A., Mohamed Kamel, A. G., Anisah, N., Noraina, A. R., Yusof, S.

Malaysian Journal of Medicine and Health Sciences, 2010;6(1):111-117.
MyJurnal

Introduction: Acanthamoeba is an ubiquitous free-living protozoa which causes serious ocular problems. Acanthamoeba keratitis is becoming more prevalent amongst contact lens wearers. The disease can cause loss of vision and blindness if not treated properly. The objective of this research is to study the sensitivity of six Acanthamoeba spp. isolates, of which three were from the clinical isolates (HKL 95, HTH 40 and HS 6) and the remaining three from environmental isolates (TTT 9, TL 3 and SMAL 8) to antimicrobial agents. Methods: The antimicrobial agents chosen for this purpose were polyhexamethylene biguanide (PHMB) and chlorhexidine. Serial dilutions were perfomed for polyhexamethylene biguanide and chlorhexidine. Cyst suspensions from the chosen isolates were exposed to PHMB and chlorhexidine respectively. After 48 hours incubation time at 30°C, each mixture was filtered and filtration membrane was put onto non-nutrient agar laid with Escherichia coli. The agar plates were incubated for three days at 30°C and examined daily until day 14 to detect the presence of Acanthamoeba trophozoites under the inverted microscope. The presence of trophozoites indicated the ineffectiveness of the antimicrobial agents. Results: Both of the antimicrobial agents tested were found to be effective against Acanthamoeba cysts from all the test strains. Polyhexamethylene biguanide gave a minimum cysticidal concentration (MCC) mean value of 2.848 μg/mL while chlorhexidine showed
MCC mean value at a concentration of 3.988 μg/mL. Conlusion: It can be concluded that the Acanthamoeba cysts were sensitive to polyhexamethylene biguanide and chlorhexidine.

Matched MeSH terms: Contact Lenses

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