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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*
Combinational system of a truncated ball lens and a hyperbolic lens for collimating a highly divergent source

Chen LC, Low AL, Chien SF

Appl Opt, 2004 Dec 10;43(35):6380-3.
PMID: 15617273

We propose the use of a truncated ball lens in a collimating system to transform a spherical wave from a highly divergent source into a plane wave. The proposed scheme, which incorporates a hyperbolic lens, is discussed, and the overall system is found to have a large acceptance angle and to be free of spherical aberration. Diffraction and polarization effects are neglected, as well as skew rays.

Matched MeSH terms: Lenses
Fulltext Comparison between point-based and ring-based technologies in Keratometric measurement among Post Myopic Laser Refractive surgery patients

Md Muziman Syah, Khairidzan Mohd Kamal, Mahfuzah Mokhtar, Aminul Hakim Sofian Sauri

International Medical Journal Malaysia, 2017;16(11):17-17.
MyJurnal

Corneal power or keratometric value represents two-third of total
refractive power of the eye. It is an important parameter in intraocular lens calculation.
Purpose of the study was to evaluate repeatability and agreement of keratometric
measurements obtained from a six points-based keratometry device; IOLMaster 500 (Carl
Zeiss Meditec AG, Jena, Germany) and two Placido disc-based keratometry devices;
Atlas Topographer 995 and 9000 models (Carl Zeiss Meditec AG, Jena, Germany). (Copied from article).

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*
Fulltext Easy lens cleaning solution for laboratory microscopes

Pramanik T, Ghosh A, Roychowdhury P

Med J Malaysia, 2005 Mar;60(1):116.
PMID: 16250297
Matched MeSH terms: Lenses*
Fulltext Changes in the morphology of corneal endothelial cells in young myopic adults after 6 months of wearing soft contact lenses: a Malaysian perspective

Ahmad A, Mohd-Ali B, Ishak B

Clin Optom (Auckl), 2018;10:109-113.
PMID: 30319302 DOI: 10.2147/OPTO.S172272

Purpose: Soft contact lens wear is most frequently associated with morphologic changes in corneal endothelial cells, but the data are scarce in Asians. This study aimed to evaluate changes in corneal endothelial cell morphology after 6 months of wearing soft hydrogel contact lenses (SH) in young myopic adults living in Kuala Lumpur.

Patients and methods: Forty-eight subjects were included in the study, 24 were fitted with SH contact lenses (A) and the rest were prescribed with glasses (B). Refraction was conducted subjectively and standard contact lens fitting protocol was followed. Corneal endothelial cell morphology (endothelial cell density, ECD; coefficient of variation, COV; cells' hexagonality, HEX; and central corneal thickness, CCT) was evaluated using specular microscope. Data were collected at baseline and after 6 months of lens wear.

Results: Mean age of all subjects was 21.23±1.30 years. All results are shown at baseline and 6 months, respectively. Mean refraction for A was -2.16±0.97 diopter sphere (DS) and -2.05±1.03 DS (P=0.49); for B was -2.72±1.51 DS and -2.73±1.51 DS (P=0.58). Mean ECD (cell/mm2) for A: 3104.19±237.30 and 3107.23±237.51 (P=0.07); for B: 3011.56±227.95 and 2983.83±244.55 (P=0.33). COV (%) for A: 46.52±8.63 and 48.53±10.65 (P=0.06); for B: 46.93±9.31 and 46.14±10.65 (P=0.88). HEX (%) for A: 46.21±10.12 and 45.15±10.01 (P=0.08); for B: 46.21±10.12 and 45.15±10.01 (P=0.12). CCT (µm) for A: 520.33±0.04 and 525.70±0.05 (P=0.41); for B: 532.00±0.04 µm and 530.00±0.05 µm (P=0.40).

Conclusion: This study found no significant change in corneal endothelial cell morphology after 6 months of wearing SH contact lenses. This is probably due to better oxygen permeability of the contact lens material, good compliance, and short wearing period.

Matched MeSH terms: Contact Lenses*
Opportunities and threats to contact lens practice: A global survey perspective

Thite N, Desiato A, Shinde L, Wolffsohn JS, Naroo SA, Santodomingo-Rubido J, et al.

Cont Lens Anterior Eye, 2021 12;44(6):101496.
PMID: 34426063 DOI: 10.1016/j.clae.2021.101496

AIM: To understand the views of contact lens (CL) practitioners across the globe regarding what they perceive as opportunities and threats in CL practice.
METHODS: A self-administered anonymised questionnaire, constructed in English and translated in six more languages, was distributed through reputed international professional bodies and academic institutions worldwide. The questionnaire included items on demographic characteristics, type of practice, and questions designed to explore practitioners' perspective on the future of their CL practice over the next five years.
RESULTS: A total of 2408 valid responses were analysed. Multifocal CLs for presbyopia, CLs for myopia control, use of daily disposable (DD) CLs for occasional wear, and biocompatible materials to improve comfort were identified as promising areas of opportunities by practitioners (all 8/10). Respondents from North America, and Europe valued DDCLs for occasional wear moderately more favourable (Median: 9/10 for all) as compared to colleagues in Asia (Median: 8/10, p

Matched MeSH terms: Contact Lenses*
Fulltext Comparison of vision-related quality of life between wearing Orthokeratology lenses and spectacles in myopic children living in Kuala Lumpur

Mohd-Ali B, Low YC, Mohamad Shahimin M, Arif N, Abdul-Hamid H, Wan Abdul-Halim WH, et al.

Cont Lens Anterior Eye, 2023 Feb;46(1):101774.
PMID: 36319519 DOI: 10.1016/j.clae.2022.101774

PURPOSE: There are limited reports available on the impact of wearing Orthokeratology (ortho-K) lenses on the quality of life of Asian children. This study evaluated and compared vision-related quality of life (VRQoL) between myopic children wearing ortho-K lenses and single-vision spectacles (SVSs), living in Kuala Lumpur, using Paediatric Refractive Error Profile (PREP) questionnaires.
METHODS: This is a cross sectional study. Myopic children who had been wearing ortho-K and SVSs for 12 months were recruited, and the questionnaires were distributed online. The PREP scores were obtained using a summary scoring method. The Shapiro-Wilk test was used to determine data normality. Unpaired t-test was performed for normally distributed data, and the Mann-Whitney test for non-normally distributed data. P

Matched MeSH terms: Contact Lenses*
Fulltext Anterior chamber implantation at University Hospital, Kuala Lumpur

Lim TK

Med J Malaysia, 1984 Sep;39(3):205-9.
PMID: 6544921

50 cases of anterior chamber intraocular lens implantation at the University Hospital, Kuala Lumpur were studied. 80% of the cases achieved visual acuity of 6/9 or better. The percentage would be higher if cases with pre-existing pathology are excluded and the period of follow-up is longer. Complications, mainly minor and non sight-threatening, are discussed.

Matched MeSH terms: Lenses, Intraocular*
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*
Towards Vision 2020 -Trends of Cataract Surgery in Melaka Hospital, A Malaysian Tertiary Center: 2007-2014

Thevi T, Abas AL

Kathmandu Univ Med J (KUMJ), 2021 2 18;18(70):122-132.
PMID: 33594017

Background Cataract surgery which is the only scientific method to treat cataracts has evolved from large incisions of intracapsular cataract excision to extracapsular cataract exicison and now modern day phacoemulsification. Anaesthesia too has progressed from general anaesthesia to local and topical anaesthesia. A variety of intraocular lenses are available ranging from rigid to foldable, multifocal and toric. Day care surgeries are becoming the norm these days. Objective Cataract surgery has advanced with new techniques and modalities. We studied the trends of cataract surgery and outcomes over the years. Method We performed secondary data analysis (National Eye Database) of cataract surgery patients in Hospital Melaka (2007 - 2014). Result Most patients were 60-69 years (mean 65.0 years). Primary cataract rose (p<0.05) but there was no difference in laterality and first or second eye (p>0.05). More patients presented with Hypertension and Diabetes (p<0.05). Pterygium encroaching the cornea showed a rise (p<0.05). Phacoemulsification (80.8%) showed a rise while Extracapsular Cataract Extraction (ECCE) (15.4%) declined (p<0.05). More Specialists operated and fewer combined surgeries were performed (p<0.001). Type of anaesthesia did not change (p>0.05). Operative complications reduced (p<0.001). Anterior chamber, scleral fixated and foldable intraocular lenses usage reduced (p<0.05). There was no change in pre-operative visual acuity (p>0.05) but postoperative vision showed a rise in good outcomes (p<0.05). Conclusion Melaka Hospital shows a rise in phacoemulsification and a decline in Extracapsular Cataract Extraction. More patients presented with primary cataracts. More Specialists operated and there was a reduction in intraoperative and postoperative complications. Post-operative visual outcomes showed a remarkable improvement. This improvement is in keeping with the aim of improved vision for all by 2020.

Matched MeSH terms: Lenses, Intraocular*
Contact lens related pseudomonas corneal ulcer: a case report

Sivaraj R, Verghese I, Lai YK, Parasakthi N

Family Physician, 1994;6:18-20.

Contact lenses provide an alternative to spectacles for many people. However, the hazard of bacterial corneal ulcers exists. This article describes a soft contact lens wearer who developed a bacterial corneal ulcer. Prompt diagnosis and treatment is essential for eradication of the infection and prevention of loss of vision.

Matched MeSH terms: Contact Lenses; Lenses
Fulltext Anti-Acanthamoeba activity of a semi-synthetic mangostin derivative and its ability in removal of Acanthamoeba triangularis WU19001 on contact lens

Chuprom J, Sangkanu S, Mitsuwan W, Boonhok R, Mahabusarakam W, Singh LR, et al.

PeerJ, 2022;10:e14468.
PMID: 36523474 DOI: 10.7717/peerj.14468

Garcinia mangostana L., also known as the mangosteen tree, is a native medicinal plant in Southeast Asia having a wide variety of pharmacologically active compounds, including xanthonoid mangostin. In this study, we examined the pharmacological activities of the selected semi-synthetic mangostin derivative, namely, amoebicidal activity, encystation inhibition, excystation activity, and removal capacity of adhesive Acanthamoeba from the surface of contact lens (CL). Among the three derivatives, C1 exhibited promising anti-Acanthamoeba activity against Acanthamoeba triangularis WU19001 trophozoites and cysts. SEM images displayed morphological changes in Acanthamoeba trophozoites, including the loss of acanthopodia, pore formation in the cell membrane, and membrane damage. In addition, the treated cyst was shrunken and adopted an irregular flat cyst shape. Under a fluorescence microscope, acridine orange and propidium iodide (AO/PI) staining revealed C1 induced condensation of cytoplasm and chromatin with the loss of cell volume in the treated trophozoites, while calcofluor white staining demonstrated the leakage of cell wall in treated cysts, leading to cell death. Interestingly, at the concentration ranges in which C1 showed the anti-Acanthamoeba effects (IC50 values ranging from 0.035-0.056 mg/mL), they were not toxic to Vero cells. C1 displayed the highest inhibitory effect on A. triangularis encystation at 1/16×MIC value (0.004 mg/mL). While C1 demonstrated the excystation activity at 1/128×MIC value with a high rate of 89.47%. Furthermore, C1 exhibited the removal capacity of adhesive Acanthamoeba from the surface of CL comparable with commercial multipurpose solutions (MPSs). Based on the results obtained, C1 may be a promising lead agent to develop a therapeutic for the treatment of Acanthamoeba infections and disinfectant solutions for CL.

Matched MeSH terms: Contact Lenses*
Fulltext Lens-induced glaucoma in a tertiary centre in northeast of Malaysia

Azhany Y, Norhayati A, Siti Raihan I, Liza Sharmini AT

Malays Fam Physician, 2014;9(2):48-52.
PMID: 25883765 MyJurnal

To determine the clinical presentations, management and outcome of lens-induced glaucoma (LIG) in Hospital Universiti Sains Malaysia.

Matched MeSH terms: Lenses
Fulltext Multi Beam Dielectric Lens Antenna for 5G Base Station

Ansarudin F, Abd Rahman T, Yamada Y, Rahman NHA, Kamardin K

Sensors (Basel), 2020 Oct 16;20(20).
PMID: 33081110 DOI: 10.3390/s20205849

In the 5G mobile system, new features such as millimetre wave operation, small cell size and multi beam are requested at base stations. At millimetre wave, the base station antennas become very small in size, which is about 30 cm; thus, dielectric lens antennas that have excellent multi beam radiation pattern performance are suitable candidates. For base station application, the lens antennas with small thickness and small curvature are requested for light weight and ease of installation. In this paper, a new lens shaping method for thin and small lens curvature is proposed. In order to develop the thin lens antenna, comparisons of antenna structures with conventional aperture distribution lens and Abbe's sine lens are made. Moreover, multi beam radiation pattern of three types of lenses are compared. As a result, the thin and small curvature of the proposed lens and an excellent multi beam radiation pattern are ensured.

Matched MeSH terms: Lenses
Fulltext Peripheral refraction with different designs of progressive soft contact lenses in myopes

Allinjawi K, Sharanjeet-Kaur SK, Akhir SM, Mutalib HA

F1000Res, 2016;5:2742.
PMID: 28163898 DOI: 10.12688/f1000research.9971.1

Aim: The purpose of this study was to compare the changes in relative peripheral refractive error produced by two different designs of progressive soft contact lenses in myopic schoolchildren. Methods: Twenty-seven myopic schoolchildren age between 13 to 15 years were included in this study. The measurements of central and peripheral refraction were made using a Grand-Seiko WR-5100K open-field autorefractometer without correction (baseline), and two different designs of progressive contact lenses (PCLs) (Multistage from SEED & Proclear from Cooper Vision) with an addition power of +1.50 D. Refractive power was measured at center and at eccentricities between 35º temporal to 35º nasal visual field (in 5º steps). Results: Both PCLs showed a reduction in hyperopic defocus at periphery. However, this reduction was only significant for the Multistage PCL (p= 0.015), (Proclear PCL p= 0.830). Conclusion: Multistage PCLs showed greater reduction in peripheral retinal hyperopic defocus among myopic schoolchildren in comparison to Proclear PCLs.

Matched MeSH terms: Contact Lenses, Hydrophilic
Fulltext New modified equation of contact lens method in determining post myopic laser refractive surgery corneal power

Md. Muziman Syah, M.M., Mutalib, H. A., Sharanjeet Kaur, M. S., Khairidzan, M. K.

International Medical Journal Malaysia, 2016;15(1):61-68.
MyJurnal

Introduction: The purpose of this study was to derive a modified equation for contact lens method (CLM) in
calculating post myopic laser refractive surgery corneal power. Methods: A total of 93 subjects who
underwent myopic laser refractive surgery at IIUM Eye Specialist Clinic were recruited. The accuracy of
postoperative corneal power using the standard CLM and newly-derived contact lens modified method
(CLMmod) were compared to the standard comparison method ; the historical method (HM). The CLMmod
equation was derived by adjusting postoperative corneal power of CLM according to amount of refractive
change. Results: The mean postoperative corneal power using standard CLM was significantly higher than
HM (mean difference: -0.24 D, p < 0.001). Fifty seven percent (n = 53 eyes) of the standard CLM results were
within ±0.50 D of HM results. The difference between postoperative corneal power using standard CLM and
HM increased significantly with the amount of refractive change (r = 0.835; p < 0.001). The mean
postoperative corneal power of CLMmod showed that there was no statistical significant difference compared
to the HM results (mean difference: 0.00 D, p= 0.964). Eighty eight percent (n = 82 eyes) of the CLMmod
results were within ±0.50 D of HM results with improvement of 31% from the standard CLM results.
Conclusion: The CLMmod equation provides more accurate calculation in determining post myopic laser
refractive surgery corneal power. In near future, this modified equation can be used as an alternative
equation to calculate postoperative corneal power when the preoperative data is unavailable.

Matched MeSH terms: Contact Lenses
Fulltext Assessment of digital camera in mapping meandering flume using close range photogrammetric technique

Udin, W. S., Ahmad, A., Ismail, Z.

Pertanika Journal of Science & Technology, 2014;22(1):123-138.
MyJurnal

In recent years image acquisition in close range photogrammetry relies on digital sensors such as digital cameras, video cameras, CCD cameras etc that are not specifically designed for photogrammetry. This study is performed to evaluate the compatibility of the digital metric camera and non-metric camera for the purpose of mapping meandering flume, using close range photogrammetric technique and further, to determine the accuracy that could be achieved using such a technique. The meandering flume provides an opportunity to conduct an experimental study in a controlled environment. In this study, the digital images of the whole meandering flume were acquired using a compact digital camera - Nikon Coolpix S560, a Single Lens Reflex (SLR) Nikon D60 and also a metric digital camera Rollei D30. A series of digital images were acquired to cover the whole meandering flume. Secondary data of ground control points (GCP) and check points (CP), established using the Total Station technique, was used. The digital camera was calibrated and the recovered camera calibration parameters were then used in the processing of digital images. In processing the digital images, digital photogrammetric software was used for processes such as aerial triangulation, stereo compilation, generation of digital elevation model (DEM) and generation of orthophoto. The whole process was successfully performed and the output produced in the form of orthophoto. The research output is then evaluated for planimetry and vertical accuracy using root mean square error (RMSE). Based on the analysis, sub-meter accuracy is obtained. It can be concluded that the differences between the different types of digital camera are small . As a conclusion, this study proves that close range photogrammetry technique can be used for mapping meandering flume using both the metric digital camera and non-metric digital camera.

Matched MeSH terms: Lenses
Taburan Formasi Semantan Semenanjung Malaysia (Semantan Formation Distribution in Peninsular Malaysia)

Kamal Roslan Mohamed

Sains Malaysiana, 1996;25.

The Semantan Formation which is Middle to Upper Triassic age, comprises a rapidly alternating sequence of carbonaceous shale, siltstone and rhyolite tuff with a few lenses of chert, conglomerate and recrystallised limestone. The shale and tuff make up the bulk of the sequence. Jaafar Ahmad (1976) was introduced the formation name of the rock sequence in Karak-Temerloh area, but the similar sequence (in term of lithology, paleontology and structural pattern) found in the other areas were given different names. After an extensive study, the following formations or part of them, may be include in the Semantan Formation; Raub Series (Scrivenor 1911); Calcareous Formation (Richardson 1939); Calcareous Series (Richardson 1947); Younger arenaceous Series (Alexander 1956); Raub Group (Alexander 1959); Jengka Pass Formation (Ichikawa et al. 1966); Kerdau Formation (Burton 1973a); part of Jelai Formation (Burton 1973a); Gemas Formation (Lum 1977); Jurong Formation (Burton 1973a); Pahang Volcanic Series (Hutchison 1973c).
Formasi Semantan merupakan jujukan batuan sedimen yang berusia Trias Tengah - Akhir di Jalur Tengah Semenanjung Malaysia. Jujukan ini terdiri daripada selang lapis batuan syal berkarbon, batu lodak, dan batu pasir yang kebanyakannya bertuf, serta terdapat kekanta konglomerat, batu kapur dan rijang dalam selang lapis ini. Syal adalah unit yang paling dominan dalam formasi ini. Jaafar Ahmad (1976) menamakan jujukan ini untuk kawasan Karak - Temerloh, tetapi jujukan yang serupa (dari segi litologi, paleontologi dan gaya struktur) juga ditemui di kawasan lain, tetapi dipanggil dengan nama lain. Dari hasil kajian menyeluruh yang telah dijalankan, didapati nama-nama unit batuan berikut atau sebahagian daripadanya mungkin merupakan penamaan yang serupa untuk Formasi Semantan, iaitu Siri Raub (Scrivenor 1911), Formasi Berkapur (Richardson 1939), Siri Berkapur (Richardson 1947), Siri Arenit Muda (Alexander 1958), sebahagian Kumpulan Raub (Alexander 1959), Formasi Jengka Pass (Ichikawa et al. 1966), Formasi Kerdau (Burton 1973a), sebahagian Formasi Jelai (Burton 1973a), Formasi Gemas (Lum 1977), Formasi Jurong (Burton 1973a) dan Siri Volkano Pahang (Hutchison 1973).

Matched MeSH terms: Lenses
Fulltext Habits of contact lens wearers toward lens care in Malaysia

Bhandari M, Hung PR

Med J Malaysia, 2012 Jun;67(3):274-7.
PMID: 23082416 MyJurnal

The purpose to do this research was to find out the habits of contact lens wearers towards lens care in this country, and to evaluate the compliance of contact lens wearers.
METHODS: All respondents underwent an interview regarding questionnaire which was carried out at the Klang Valley and Sabah, Malaysia by trained bilingual optometrists. The questionnaire was obtained from a study by Yvonne Wu et al., 2010. The questionnaire included information about respondents' demographics, contact lens hygiene behaviors and attitudes toward lens care. Comparison between groups and certain factors of lens care were analyzed.
RESULTS: Within the 100 respondents, 74% were female. The majority used monthly disposable lens (53%, 53/100), 35% (35/100) wore daily lens, 3% (3/100) wore biweekly disposable lens, 8% (8/100) wore quarter-yearly (3 months) lens, and only a participant (1%) used conventional lenses. The major non-compliance aspect that found out from this research were poor lens case (46%), inadequate cleaning of lens before storing (38%) and wearers not remembering how often they were advised to return for an aftercare (24%).
CONCLUSION: The poor lens care hygiene, inadequate cleaning of lens before storing may due to lack of proper advice to the contact lens wearers during examination or lack of awareness of aftercare visit.

Matched MeSH terms: Contact Lenses*

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