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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 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 In vitro effects of multi-purpose contact lens disinfecting solutions towards survivability of Acanthamoeba genotype T4 in Malaysia

Mohd Hussain RH, Afiqah WN, Abdul Ghani MK, Khan NA, Siddiqui R, Anuar TS

Saudi J Biol Sci, 2021 Apr;28(4):2352-2359.
PMID: 33911949 DOI: 10.1016/j.sjbs.2021.01.030

The incidence of Acanthamoeba keratitis has been increasing since the previous decades, especially among contact lens users. This infection is majorly caused by the use of ineffective contact lens disinfecting solution. Thus, this study was conducted to evaluate the in vitro effects of multi-purpose disinfecting solutions (MPDS) against Acanthamoeba trophozoites and cysts. Acanthamoeba genotype T4 isolated from contact lens paraphernalia and an environmental strains were propagated for trophozoite or cyst-containing culture and adjusted in final concentration of 1 × 105 cells/ml. Amoebicidal and cysticidal assays were conducted by incubating trophozoites and cysts with OPTI-FREE® Express®, ReNu® Fresh™, Complete® Multi-Purpose Solution and AVIZOR Unica® Sensitive according to the manufacturer's minimum recommended disinfectant time (MMRDT) for up to 12 h at 30 ⁰C. Trypan blue hemocytometer-based microscopic counts determined amoebicidal and cysticidal effects. The viability of Acanthamoeba trophozoites and cysts was confirmed by re-inoculated them in the 1.5% non-nutrient agar plates. It was found that none of the MPDS showed amoebicidal and cysticidal effects during the MMRDT. However, OPTI-FREE® Express® demonstrated a significant differences in average cell reduction for both stages within MMRDT. When subjected to 12 h exposure, both OPTI-FREE® Express® and ReNu® Fresh™ led to significant reduction in the number of trophozoite and cyst cells. Notably, Complete® Multi-Purpose Solution and AVIZOR Unica® Sensitive did appreciably improve the solution effectiveness towards trophozoite cells when incubated for 12 h. All MPDS were largely ineffective, with 100% survival of all isolates at MMRDT, while OPTI-FREE® Express® showed limited amoebicidal activity against the contact lens paraphernalia isolate, however, it was more against the environmental strains after 12 h incubation time. The commercially available MPDS employed in this research offered minimal effectiveness against the protozoa despite the contact time. Improvement or development of new solution should consider the adjustment of the appropriate disinfectant concentration, adequate exposure time or the incorporation of novel chemical elements, which are effective against Acanthamoeba for accelerated disinfecting and more reduction of potential exposure of contact lens users to Acanthamoeba keratitis.

Matched MeSH terms: Contact Lenses
Fulltext The consistency of retinal image size measurement using smartphone application

Nura Syahiera Ibrahim, Firdaus Yusuf @ Alias, Norsham Ahmad

Malaysian Journal of Medicine and Health Sciences, 2020;16(3):15-20.
MyJurnal

Introduction: Unequal retinal image size (RIS) or aniseikonia is usually related with anisometropia. Higher dif- ferences of RIS may manifest symptoms such as dizziness, headache or disorientation. In worst case might cause suppression that leads to amblyopia. Current study aims to evaluate the consistency of aniseikonia measurement in Smart Optometry smartphone application among myopic, hyperopic, and astigmatic simulated anisometropia and real anisometropia groups. Methods: Fifteen real anisometropes (refractive error; -0.50 until -6.00 diopters; D) and fifteen emmetropes (refractive error: -0.25 until +0.50D) were recruited. Real anisometropes wore their habitual spectacle correction while each emmetropes were fitted using soft contact lenses of +4.00DS, -4.00DS and -4.00DC with base curve 8.6 and total diameter 14.2mm in random order to mimic myopic-, hyperopic- and astigmat- ic-anisometropia before testing. Participants with any ocular disease and binocular vision problem were excluded. The consistency of aniseikonia measurement was determined in two visits, separated by at least 24-hour interval. Three repetitive measurements were taken in each visit. Results: Independent t-test and paired t-test showed that real and simulated anisometropia gave insignificant aniseikonia percentage, p>0.05. ICC findings revealed moder- ate-to-good agreement for all simulated and real groups. Bland Altman analysis between two visits exhibited good agreement among all simulated group; myopic (mean difference 0.2047; 95%CI:-1.1386-1.549), hyperopic (mean difference 0.2200; 95%CI:-0.9286-1.3686) and astigmatic (mean difference 0.2533; 95%CI:-0.7114-1.2180). Real anisometropes demonstrated good agreement with bias value of 0.2247(95%CI:-0.9162-1.3656) using Bland Altman plot. Conclusion: Smart Optometry application provides consistent measurement of aniseikonia regardless any types of anisometropia.

Matched MeSH terms: Contact Lenses, Hydrophilic
Fulltext Relationship between Routine Handling Practices with Potential Pathogenic Bacteria Isolated from Contact Lenses Among Students in UiTM Negeri Sembilan

Adam Zafdri Md Zali, Rashidah Iberahim

Journal of Academia Universiti Teknologi MARA Negeri Sembilan, 2021;9(1):106-116.
MyJurnal

Pseudomonas aeruginosa and Staphylococcus aureus are types of bacteria known to cause bacterial keratitis. Pseudomonas aeruginosa causes bacterial keratitis by adhering to the surface of the contact lenses, when the P. aeruginosa are in contact with the eye, resulting in infectious keratitis. As for Staphylococcus aureus, when there is a predisposing factor such as wearing expired or extended use of contact lenses (contact lenses that can be used continually for up to one week even while sleeping) weaken the individual defences and leads to the development of bacterial keratitis. Both bacteria are capable to infect eye cornea and lead to bacterial keratitis through contact lenses wearer. The findings of this study provide information on the importance of routine practices in handling contact lenses to help reduce the incidence of bacterial keratitis caused by wear contact lenses in an individual. The side effect of wearing contact lenses such as redness of the eye and keratitis due to the infection by pathogenic bacteria which comes from the behavior and low hygiene level management of individual had led the study to create awareness to contact lenses wearer. In this study, 25 soft and hard contact lenses with purposed for colored or toric contact lenses were obtained among UiTM Negeri Sembilan students. The users required to answer the questionnaire form regarding the type, behavior, and routine practices of their contact lenses. Pathogenic bacteria were isolated using the cotton swab technique and cultured on nutrient broth. The streak technique was used to cultured bacteria from broth to nutrient agar, blood agar, and MacConkey agar. Later, the identification of bacteria was carried out using biochemical tests and microscopic observation. From the laboratory results, 84% of the tested contact lenses contained pathogenic bacteria on their surface. These findings concluded that the presences of pathogenic microorganisms on the contact lenses used closely related to the behavior in handling and hygenic practices level by the contact lenses users.

Matched MeSH terms: Contact Lenses
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 Prevalence of bimaxillary protrusion among UiTM orthodontic patients

Ruqoyyah Muslimat Othman, Noor Airin Aidil Koay, Sarah Haniza Abdul Ghani, Noraina Hafizan Norman

Compendium of Oral Science, 2019;6(1):1-8.
MyJurnal

Objective: To determine the prevalence of bimaxillary protrusion in general and the prevalence of skeletal Class I and dental Class I bimaxillary protrusion/ proclination among orthodontic patients attending postgraduate orthodontic clinic at Faculty of Dentistry, Universiti Teknologi MARA (UiTM), Sungai Buloh, Malaysia. Materials and Methods: This is a cross sectional study which was carried out in two stages. The first part involves a random selection of 100 extra-oral profile photographs taken from postgraduate orthodontic residents’ patient list. The photographs were taken using Canon digital SLR camera EOS 70D with macro lens EF 100mm (Canon Inc., Tokyo, Japan) with patients in natural head position. The photographs were visually analysed for its bimaxillary protrusion features by two operators. The second part comprises of analyses of extra-oral profile photographs as well as intra-oral photographs of right buccal segment view which was conducted in two separate sittings. In the first sitting, five assessors analysed 259 extra - and intra-oral photographs followed by 40 photographs assessed in the second sitting for skeletal and dental Class I bimaxillary protrusion/ proclination. Statistical analysis for Kappa score was performed to assess the agreement between assessors using SPSS version 23 and Stata version 13. Results: The first part of the study showed an average prevalence of 34% with bimaxillary protrusion in 100 orthodontic patients. Whilst in the second part, prevalence of skeletal and dental Class I bimax ranging from 28 -33 per cent and 38-40 per cent respectively with very good and good inter-reliability agreement for both component. Conclusion: The prevalence of bimaxillary protrusion in general among UiTM orthodontic patients was found to range from 31 per cent to 37 per cent. Whilst the prevalence of skeletal and dental Class I bimax ranging from 28-33 per cent and 38-40 per cent respectively.

Matched MeSH terms: Lenses
Fulltext A case of trauma related Acanthamoeba keratitis

Kamel AG, Faridah H, Yusof S, Norazah A, Nakisah MA

Trop Biomed, 2004 Dec;21(2):135-8.
PMID: 16493405 MyJurnal

Acanthamoeba is an uncommon cause of keratitis but one of the most severe because of the prolonged and painful course of the disease and poor visual outcome. Although contact lens use is the principal risk factor, about 10% of cases occur following trauma and exposure to contaminated soil or water. Two cases of Acanthamoeba keratitis involving women contact lens wearers have previously been reported in Malaysia but this is the first time, a non contact lens related Acanthamoeba keratitis is reported. The case involved a 28 year old Indonesian male construction worker who had a trauma of the right eye during work. His eye was struck by sand and dust particles after which he quickly washed with water from an open tank at the construction site. He experienced pain, redness, glaring and blurring of vision of the right eye three days later. The diagnosis was missed at initial presentation but culture of the corneal scraping had proven Acanthamoeba as the aetiological agent. The history and clinical findings of this trauma related Acanthamoeba keratitis are briefly discussed.

Matched MeSH terms: Contact Lenses
Fulltext Protein and microbial determinations on worn contact lenses cleaned conventionally using the Lens2® automatic lens cleaner

Haliza Abdul Mutalib, Ahmad Rohi Ghazali, Noor Suhailah Ali

Jurnal Sains Kesihatan Malaysia, 2008;6(1):11-21.
MyJurnal

The accumulation of tear film proteins as well as microbes colonization onto worn contact lenses can be eliminated conventionally by mechanical rubbing during the cleaning process. Lens2® functions in rotation manner to loosen the deposits on the contact lens and has antimicrobial coating to keep lenses away from contamination. The objective of this study was to determine the efficiency of Lens2® to remove deposited protein and reduce microbial contamination compared to conventional method. Twenty-eight subjects each wore a pair of contact lens FDA Group 1 (Polymacon, SoftLens® 38, Bausch & Lomb) for one month and cleaned them using multipurpose solution (COMPLETE® MoisturePLUSTM, Advanced Medical Optics) separately using two different methods. The right lens was cleaned conventionally while the left lens were cleaned using the Lens2®. The control group of thirteen subjects each wore a pair of contact lens for the same period and cleaned both conventionally. These lenses and its cases were then analyzed for protein deposition using Bichinchoninic Acid Assay (BCA) Kit (Sigma, USA) in 96-well plate. Microbial contamination was determined by culturing the samples on nutrient agar for bacteria and fungi and non-nutrient agar for amoeba isolation. The mean of total protein on control lenses (17.014 ± 13.246 µg/mL) was not significantly different from those on the Lens2® (21.623 ± 19.127 µg/mL). There were also low growth numbers of amoeba in each group of samples. Interestingly, there were no growths of amoeba from all Lens2® samples collected. There was also low growth numbers of bacteria in each sample group whereby Lens2® had the lowest growth of bacteria. No growth of fungi was obtained from all samples. The automatic lens cleaner, Lens2® was found to be as efficient as the conventional cleaning method. However, the Lens2® has additional advantage because of its antimicrobial material and need shorter time in the cleaning process as well as easy and effective.

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
Fulltext Sequelae of neglected senile cataract

Azhany Y, Hemalatha C, Nani D, Rosediani M, Liza-Sharmini A

Malays Fam Physician, 2013;8(1):33-7.
PMID: 25606266 MyJurnal

Cataract is the most common cause of blindness in the world. An attack of phacolytic and phacomorphic glaucoma as a result of neglected cataract constitutes a medical emergency that must be addressed immediately. Ocular emergencies such as these is challenging for the surgeon with guarded or poor prognosis. We describe the presentation, management and prognosis of three cases of phacomorphic and phacolytic glaucoma. All three patients underwent aggressive management of intraocular pressure. Despite successful cataract operation with implantation of intraocular lens, there was only mild improvement of the vision. Optic nerve and pupil functions were permanently affected following the insult. Phacomorphic and phacolytic glaucoma present a very challenging problem to the surgeon with poor visual outcome. Public health education and awareness are important and health workers should encourage patients with cataract to seek early treatment for better prognosis.

Matched MeSH terms: Lenses, Intraocular
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
Fulltext The effectiveness of gentamicin against acanthamoeba cysts in vitro

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

Malaysian Journal of Medicine and Health Sciences, 2012;8(2):51-54.
MyJurnal

Acanthamoeba is a free-living protozoa which causes serious ocular problem. Acanthamoeba keratitis is becoming more prevalent amongst contact lens wearers and it can cause loss of vision and blindness if not treated properly. The objective of this research is to determine the effectiveness of gentamicin against six Acanthamoeba spp. isolates, of which three were clinical isolates (HS 6, HKL 95, HTH 73) and three environmental isolates (SMAL 7, SMAL 8, TTT 9). Cyst suspension from the chosen isolates were exposed to gentamicin. After 48 hours of incubation at temperature of 30°C and 37oC, 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 30oC and 37oC and the plates were examined daily until day 14 to look for the presence of Acanthamoeba trophozoites under inverted microscope. The presence of trophozoites indicated the ineffectiveness of gentamicin. Gentamicin was found to be effective against Acanthamoeba cysts from all the test strains at both incubation temperatures. The minimum cysticidal concentration (MCC) mean value of gentamicin was 0.193 mg/mL at 30oC and 0.229 mg/mL at 37oC. So, we concluded that gentamicin has cysticidal potential towards Acanthamoeba.

Matched MeSH terms: Contact Lenses
Some aspects of refractive errors in West Malaysia

Chandran S, Ooi Eu-sen V

Med J Malaya, 1971 Mar;25(3):193-7.
PMID: 4253246
Matched MeSH terms: Contact Lenses
Fulltext Contact lens related Elizabethkingia meningoseptica keratitis-a first Southeast ASEAN case report & literature review

Ang, Wen-Jeat, Embong Zunaina, Raja Omar Raja Norliza, Abdul Jalil Fadzillah

Journal of Biomedical and Clinical Sciences, 2017;2(1):1-4.
MyJurnal

We describe the first clinical case of contact lens related corneal ulcer caused by Elizabethkingia meningosepticaregistered in Southeast Asia. A 20-year-old female student who wasa regular soft contact lens wearer, presented with pain, photophobia and blurring of vision of the right eye for 3 days. On slit lamp examination, there was a small paracentral anterior stromal infiltrate with an overlying epithelial defect. Microbiological cultures from corneal scrapings, contact lens and its casing were positive for E.meningoseptica. Due to high likelihood of contact lens contamination causing keratitis, topical fortified gentamicin0.9% and ceftazidime 5% were administered empirically. Topical vancomycin 5% was later added tailoring to the culture and sensitivity of the organism. After 8 weeks of treatment, the keratitis subsided and corneal epithelial defect completely healed with residual corneal opacity. Even though uncommon, contact lens related E.meningosepticakeratitis can occur in healthy immunocompetent individuals with no ocular comorbidities.

Matched MeSH terms: Contact Lenses, Hydrophilic
Fulltext Dislocated posterior chamber intraocular lens (PCOIL) in patients with retinitis pigmentosa (RP)

Lam, C.S., Mushawiahti, M., Bastion, M.L.C.

Journal of Surgical Academia, 2017;7(1):38-42.
MyJurnal

Subluxation or dislocation of PCIOL is one of the complications of cataract operation in RP patients. This paper reports the presentation of PCIOL dislocation and subluxation and the management and outcome in 3 eyes of 2 RP patients. Two medical records of patients with RP who developed dislocated or subluxated PCIOL and subsequently underwent explantation of the dropped IOL were evaluated. Two patients had bilateral eye cataract operation done and had PCIOL implanted. Patient 1 developed left eye subluxated PCIOL inferiorly after 2 years of the cataract operation and right eye dislocated PCIOL anteriorly 4 years after cataract operation. Patient 2 develop right eye subluxated PCIOL inferiorly after 12 years of the cataract operation. Patient 1 with right eye dislocated PCIOL underwent intraocular lens (IOL) explantation and was left aphakic as her visual prognosis was poor due to advanced RP. The left IOL remained within the visual axis despite subluxation and no intervention has been done. Patient 2 with right eye subluxated PCIOL underwent IOL explantation and anterior chamber intraocular lens (ACIOL) implantation. ACIOL remained stable and visual acuity improved post-operation. Both the operations were uneventful. Post-operatively, there was no elevated intraocular pressure and no prolonged ocular inflammation, which required prolonged anti-inflammatory and no retinal detachment was seen. Both patient and surgeon should be aware of potential PCIOL subluxation or dislocation in RP. The presentation may be as late as more than a decade after the cataract operation.

Matched MeSH terms: Lenses, Intraocular
Phomopsidione nanoparticles coated contact lenses reduce microbial keratitis causing pathogens

Bin Sahadan MY, Tong WY, Tan WN, Leong CR, Bin Misri MN, Chan M, et al.

Exp Eye Res, 2019 01;178:10-14.
PMID: 30243569 DOI: 10.1016/j.exer.2018.09.011

Microbial keratitis is the infection caused by pathogenic microorganisms that commonly occurs among the contact lens users. Various antimicrobial compounds were coated on contact lenses to kill keratitis causing microorganisms, however these compounds caused several adverse side effects. Hence, the aim of this study is to develop a silicone hydrogel contact lens coated with phomopsidione nanoparticle that inhibit keratitis causing clinical isolates. Phomopsidione nanoparticles were synthesized using polyvinyl alcohol as encapsulant. The nanoparticles showed an average size of 77.45 nm, with neutral surface charge. Two drug release patterns were observed in the drug release profile, which are the initial slow release phase with extended drug release (release rate 46.65 μg/h), and the burst release phase observed on Day 2 (release rate 2224.49 μg/h). This well-regulated drug delivery system enables the control of drug release to meet the therapeutic requirements. On agar diffusion assay, 3 out of 5 test microorganisms were inhibited by phomopsidione nanoparticle coated contact lenses, including two Gram negative bacteria. Besides, all test microorganisms showed at least 99% of growth reduction, with the treatment of the contact lens model. The drug loaded onto the nanoparticles is sufficient to prevent the bacterial growth. In conclusion, this study provides an effective alternative to combat keratitis-causing microorganisms among contact wearers.

Matched MeSH terms: Contact Lenses
Global trends in myopia management attitudes and strategies in clinical practice - 2019 Update

Wolffsohn JS, Calossi A, Cho P, Gifford K, Jones L, Jones D, et al.

Cont Lens Anterior Eye, 2020 02;43(1):9-17.
PMID: 31761738 DOI: 10.1016/j.clae.2019.11.002

PURPOSE: A survey in 2015 identified a high level of eye care practitioner concern about myopia with a reported moderately high level of activity, but the vast majority still prescribed single vision interventions to young myopes. This research aimed to update these findings 4 years later.
METHODS: A self-administrated, internet-based questionnaire was distributed in eight languages, through professional bodies to eye care practitioners globally. The questions examined: awareness of increasing myopia prevalence, perceived efficacy of available strategies and adoption levels of such strategies, and reasons for not adopting specific strategies.
RESULTS: Of the 1336 respondents, concern was highest (9.0 ± 1.6; p 

Matched MeSH terms: Contact Lenses, Hydrophilic
Novel Polyvinyl Pyrrolidone-Loaded Olopatadine HCl-Laden Doughnut Contact Lens to Treat Allergic Conjunctivitis

Xue Y, Zhang W, Lei Y, Dang M

J Pharm Sci, 2020 05;109(5):1714-1724.
PMID: 32007507 DOI: 10.1016/j.xphs.2020.01.022

Olopatadine HCl is an antiallergic drug used for the management of allergic conjunctivitis. Currently, it is delivered via eye drop solution, which is highly inefficient due to low bioavailability. Silicone contact lenses can be used to sustain the release of ophthalmic drugs. However, the presence of drug alters the optical transmittance and physical properties of the contact lens. The objective was to design a novel polyvinyl pyrrolidone (PVP)-coated olopatadine-ethyl cellulose microparticles-laden doughnut contact lens to sustained ocular delivery with limited alteration to the optical and swelling properties of the contact lens. The doughnut was implanted within the periphery of the lens using modified casting technique. Olopatadine HCl was loaded by soaking (SM-OL), direct loading (DL-OL), and doughnut casting method (DNT-OL). PVP (comfort agent) was loaded on the surface of contact lens for all the batches via novel curing technique. The in vitro olopatadine HCl release data of SM-OL (up to 48-72 h) and DL-OL batches (up to 72 h) showed high burst release, whereas DNT-OL batch showed sustained release up to 120 h without significant (p > 0.05) alteration in the optical and swelling properties of contact lens. All the batches showed sustained release of PVP up to 120 h. The in vivo studies in the rabbit tear fluid showed improvement in the olopatadine HCl and PVP retention time in comparison to eye drop solution. The PVP-loaded DNT-OL-500 lens showed tear stabilization (comfort wear) in Schirmer strip test (rabbits) with no protein adherence in comparison to DNT-OL-500 lens without PVP. The study demonstrated the successful delivery of olopatadine HCl and PVP-K30 from the doughnut contact lens for the extended period with limited alteration to the optical and swelling properties of contact lens.

Matched MeSH terms: Contact Lenses
Fulltext Acanthamoeba-mediated cytopathic effect correlates with MBP and AhLBP mRNA expression

Ng SL, Nordin A, Abd Ghafar N, Suboh Y, Ab Rahim N, Chua KH

Parasit Vectors, 2017 12 28;10(1):625.
PMID: 29282148 DOI: 10.1186/s13071-017-2547-0

BACKGROUND: In recent years, the concern of Acanthamoeba keratitis has increased since the infection is often associated with contact lens use. Partial 18S rRNA genotypic identification of Acanthamoeba isolates is important to correlate with pathophysiological properties in order to evaluate the degree of virulence. This is the first report of genotypic identification for clinical isolates of Acanthamoeba from corneal scrapings of keratitis in Malaysia. This study is also the first to correlate the mRNA expression of MBP and AhLBP as virulent markers for axenic strains of Acanthamoeba.
RESULTS: In this study, ten clinical isolates were obtained from corneal scrapings. Rns genotype and intra-genotypic variation at the DF3 region of the isolates were identified. Results revealed that all clinical isolates belonged to the T4 genotype, with T4/6 (4 isolates), T4/2 (3 isolates), T4/16 (2 isolates) and one new genotype T4 sequence (T4/36), being determined. The axenic clinical isolates were cytopathogenic to rabbit corneal fibroblasts. MBP and AhLBP mRNA expression are directly correlated to Acanthamoeba cytopathic effect.
CONCLUSIONS: All ten Malaysian clinical isolates were identified as genotype T4 which is predominantly associated with AK. Measuring the mRNA expression of Acanthamoeba virulent markers could be useful in the understanding of the pathogenesis of Acanthamoeba keratitis.

Matched MeSH terms: Contact Lenses

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