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  1. Asfahani J, Samuding K, Mostapa R, Othman O
    Appl Radiat Isot, 2021 Jan;167:109296.
    PMID: 33022484 DOI: 10.1016/j.apradiso.2020.109296
    Natural gamma ray well logging technique is used to characterize the radioactivity (GR) laterally and vertically in Banting district, SW of Malaysia. Seven drilled boreholes, along N-S profile with their natural gamma ray records are utilized to compute the heat production (HP) parameter, based on the Bucker and Rybach relationship.The analysis of 3467 measured points in those boreholes indicates that GR varies between 6.24 API and 358.4 API with an average of 79.95 API, while HP varies between 0.086 and 5.65 μw/m3 with an average of 1.25 μw/m3.The multi-fractal Concentration-Number (C-N) is used to characterize the radioactivity and heat production variations and to isolate different GR and HP populations in the study region. The high radioactivity and heat production ranges are mainly related to the silty clay layers, accompanied by uranium and thorium.
  2. Yagoub MFS, Khalifa OO, Abdelmaboud A, Korotaev V, Kozlov SA, Rodrigues JJPC
    Sensors (Basel), 2021 Jul 31;21(15).
    PMID: 34372449 DOI: 10.3390/s21155206
    Wireless Sensor Networks (WSNs) have gained great significance from researchers and industry due to their wide applications. Energy and resource conservation challenges are facing the WSNs. Nevertheless, clustering techniques offer many solutions to address the WSN issues, such as energy efficiency, service redundancy, routing delay, scalability, and making WSNs more efficient. Unfortunately, the WSNs are still immature, and suffering in several aspects. This paper aims to solve some of the downsides in existing routing protocols for WSNs; a Lightweight and Efficient Dynamic Cluster Head Election routing protocol (LEDCHE-WSN) is proposed. The proposed routing algorithm comprises two integrated methods, electing the optimum cluster head, and organizing the re-clustering process dynamically. Furthermore, the proposed protocol improves on others present in the literature by combining the random and periodic electing method in the same round, and the random method starts first at the beginning of each round/cycle. Moreover, both random and periodic electing methods are preceded by checking the remaining power to skip the dead nodes and continue in the same way periodically with the rest of the nodes in the round. Additionally, the proposed protocol is distinguished by deleting dead nodes from the network topology list during the re-clustering process to address the black holes and routing delay problems. Finally, the proposed algorithm's mathematical modeling and analysis are introduced. The experimental results reveal the proposed protocol outperforms the LEACH protocol by approximately 32% and the FBCFP protocol by 8%, in terms of power consumption and network lifetime. In terms of Mean Package Delay, LEDCHE-WSN improves the LEACH protocol by 42% and the FBCFP protocol by 15%, and regarding Loss Ratio, it improves the LEACH protocol by approximately 46% and FBCFP protocol by 25%.
  3. Khalifa OO, Amirah Bt Sharif N, Saeed RA, Abdel-Khalek S, Alharbi AN, Alkathiri AA
    Contrast Media Mol Imaging, 2021;2021:1101911.
    PMID: 34992507 DOI: 10.1155/2021/1101911
    Quantum computing is a computer development technology that uses quantum mechanics to perform the operations of data and information. It is an advanced technology, yet the quantum channel is used to transmit the quantum information which is sensitive to the environment interaction. Quantum error correction is a hybrid between quantum mechanics and the classical theory of error-correcting codes that are concerned with the fundamental problem of communication, and/or information storage, in the presence of noise. The interruption made by the interaction makes transmission error during the quantum channel qubit. Hence, a quantum error correction code is needed to protect the qubit from errors that can be caused by decoherence and other quantum noise. In this paper, the digital system design of the quantum error correction code is discussed. Three designs used qubit codes, and nine-qubit codes were explained. The systems were designed and configured for encoding and decoding nine-qubit error correction codes. For comparison, a modified circuit is also designed by adding Hadamard gates.
  4. Ho NWW, Catherine Bastion ML, Mustapha M, Othman O
    Cureus, 2021 Jul;13(7):e16685.
    PMID: 34462703 DOI: 10.7759/cureus.16685
    Intraorbital foreign bodies are a common complication of eye trauma. If improperly managed, it may lead to severe complications. In this case series, the first case is an intraconal foreign body after being hit by a stone, and the second case is an intraconal foreign body from a metallic piece of a crane wheel. We discuss the role of imaging in confirming the presence of the foreign body, localizing it, and guiding when surgery is indicated. Our two cases showed differences in the management approach, as the first case had multiple issues requiring multiple procedures. However, the second case had a relatively specific pathology, management, and outcome. With adequate treatment and a bit of luck, the visual outcome can be satisfactory.
  5. Maniam A, Zuhaimy H, Vendargon FMM, Othman O
    Cureus, 2021 Nov;13(11):e19450.
    PMID: 34912600 DOI: 10.7759/cureus.19450
    BACKGROUND: Chronic myeloid leukaemia (CML) presenting with only ocular manifestations either at the initial stage of diagnosis or at relapse is uncommon. We report two cases of CML presenting with isolated visual symptoms.

    CASE SERIES: The first case is a 21-year-old healthy gentleman who presented with left eye painless loss of vision for a one-week duration. Visual acuity was 6/60 in the left eye and 6/6 in the right eye. There were scattered retinal haemorrhages in both eyes and a sub-macular bleed over the left eye. The full blood count revealed a high white cell count of 134.6 × 109/L. Peripheral blood smear showed hyper-leucocytosis with absolute eosinophilia and basophilia and the presence of blasts suggestive of CML thus chemotherapy was commenced. The second case is a 28-year-old in haematological, molecular, and cytogenic remission from CML for the past two years, presented with left eye painless vision loss for five days duration. Vision in the left eye was counting fingers. There was a large subretinal mass involving the left optic disc. Magnetic resonance imaging of the brain and orbit showed an elliptical orbital mass at the left globe posteriorly with diffuse thickening of the optic nerve. The patient was diagnosed as CML relapsed to the left optic nerve. He underwent intrathecal chemotherapy and orbital irradiation.

    CONCLUSION: Both these cases are unique since the manifestation of CML was with only ocular features at the time of presentation as per in the first case during the initial diagnosis and in the second case during relapse. This highlights that it is evident that the knowledge of ocular involvement in leukaemia is crucial since the eye is the only organ where leukemic infiltration to nerves and blood vessels can be observed directly. Recognizing fundus changes in leukaemia allows earlier diagnosis and prompt treatment. These case reports highlight the importance of recognizing early fundus changes, which should allow earlier diagnosis and treatment.

  6. Wai Wye NH, Naffi AA, Othman O, Bastion MC
    Cureus, 2021 Oct;13(10):e18700.
    PMID: 34790457 DOI: 10.7759/cureus.18700
    Craniopharyngioma is a rare and benign sellar and suprasellar region tumour. It rarely manifests during pregnancy. We report a 32-year-old primigravida at 19 weeks of gestation with a craniopharyngioma, presenting with visual disturbances during pregnancy. Her vision was 6/9 OD and counting fingers OS with a relative afferent pupillary defect in the left eye. Fundi were normal bilaterally. Visual field testing showed a nasal field defect OD and generalized depression OS. Brain magnetic resonance imaging revealed a suprasellar tumour with chiasmatic compression. Craniotomy and excision of the tumour were done at 20 weeks of gestation. Histopathological examination was consistent with craniopharyngioma. Postoperatively, mother and foetus were stable. Vision improved from counting fingers to 6/6 OS and remained at 6/9 OD. Subsequently, she delivered a healthy baby at term. Such rare and difficult cases warrant close multidisciplinary cooperation pre- and post-operatively to attain optimal outcomes for both mother and baby. By optimizing the patient's medical condition, risks of complications may be reduced. A poor pre-operative vision should also not deter surgical intervention as a proven good visual outcome is achievable.
  7. Basiron SF', Khaw AML, Ch'ng TW, Othman O
    BMJ Case Rep, 2022 Mar 29;15(3).
    PMID: 35351754 DOI: 10.1136/bcr-2021-248259
    An adolescent female with underlying bilateral pseudophakia and idiopathic intermediate uveitis had reduced visual acuity due to posterior capsule opacification (PCO). The rapid progression and different morphological formations of Elschnig pearls were not influenced by the uveitis and immunosuppressive treatment. No capsulotomy was performed, and the PCO regressed spontaneously over time.
  8. Zahari KM, Rosland SF, Hannie C, Othman O
    Cureus, 2024 May;16(5):e61289.
    PMID: 38947604 DOI: 10.7759/cureus.61289
    Streff syndrome is a non-malingering visual disturbance commonly affecting near and color vision, which is prevalent in the younger population. This case report presents Streff-like syndrome in a middle-aged woman. A 47-year-old woman with underlying major depressive disorder presented with bilateral reduced vision and a constricted visual field for one week. These symptoms were accompanied by additional neurological complaints of headache, weakness, and numbness triggered after a stressful event that affected her work performance. Examinations revealed reduced vision more toward near, diminished red saturation, color vision deficiencies, and bilateral tubular visual fields. Notably, the relative afferent pupillary defect was negative, with both anterior and posterior segments normal. Neuroimaging and inflammatory workup results were within normal limits. An additional +1.00 lens improved her symptoms and visual acuities. Collaborative management involving psychiatry, neurology, and ophthalmology, including psychotherapy, led to significant symptom improvement. At the five-month follow-up, the patient experienced a complete resolution of her visual symptoms. Although Streff syndrome is a primary visual problem, additional psychogenic factors may add to variable cases. This case underscores the importance of recognizing stress-induced psychogenic manifestation, particularly in patients with underlying mental health conditions, and emphasizes an interdisciplinary management approach.
  9. Teo SK, Mohd Khialdin S, Yong MH, Othman O, Ami M
    Optom Vis Sci, 2020 Dec;97(12):1018-1022.
    PMID: 33252541 DOI: 10.1097/OPX.0000000000001607
    SIGNIFICANCE: Ocular tilt reaction (OTR) is an abnormal eye-head postural reaction that consists of skew deviation, head tilt, and bilateral ocular torsion. Understanding of the pathway of the vestibulo-ocular reflex (VOR) is essential because this will help to localize the pathology.

    PURPOSE: The aim of this study was to report a case of OTR with contralateral internuclear ophthalmoplegia (INO) and fifth and seventh cranial nerve palsies.

    CASE REPORT: A 51-year-old gentleman with underlying diabetes mellitus presented with sudden onset of diplopia for 3 days. On examination, his visual acuity was 20/30 bilaterally without a relative afferent pupillary defect. He had a right OTR consisting of a right head tilt, a skew deviation with a left eye hypertropia, and bilateral ocular torsion (right excyclotorsion and left incyclotorsion) with nystagmus. He also had a left adduction deficit and right abduction nystagmus consistent with a left INO. Ocular examination revealed evidence of proliferative diabetic retinopathy bilaterally. Two days after the initial presentation, the patient developed left seventh and fifth cranial nerve palsies. MRI showed left pontine infarction and multiple chronic lacunar infarctions. There was an incidental finding of a vascular loop compression on cisternal portions of the left trigeminal, facial, and vestibulocochlear nerves. Antiplatelet treatment was started on top of a better diabetic control. The diplopia was gradually resolved with improved clinical signs. In this case, the left pontine infarction had likely affected the terminal decussated part of the vestibulocochlear nerve from the right VOR pathway, medial longitudinal fasciculus, and cranial nerve nuclei in the left pons.

    CONCLUSIONS: The OTR can be ipsilateral to the lesion if the lesion is before the decussation of the VOR pathway in the pons, or it can be contralateral to the lesion if the lesion is after the decussation. In case of an OTR that is associated with contralateral INO and other contralateral cranial nerves palsy, a pathology in the pons that is contralateral to the OTR should be considered. Neuroimaging study can hence be targeted to identify the possible cause.

  10. Kuan HC, Ivan Cheng EY, Yong MH, Wan Abdul Halim WH, Othman O
    Cureus, 2021 Dec;13(12):e20822.
    PMID: 35141078 DOI: 10.7759/cureus.20822
    Corneal nodular lesions are not uncommon in clinical practice. Diagnosing and managing this condition can be challenging due to its variable causes. This article highlights three cases of corneal nodular lesions. A common clinical pathway for the diagnosis and treatment of cornea nodular lesions is discussed. Two young females and an elderly man presented with a unilateral corneal nodule of variable duration, which was further demonstrated on anterior segment optical coherence tomography (AS-OCT). Several diagnoses were made after thorough history and examination which include herpetic stromal keratitis, phlyctenular keratoconjunctivitis secondary to blepharitis, and Salzmann nodular degeneration. All cases were initiated on topical antibiotics and topical steroids with additional medication or surgical procedure onboard according to their clinical condition. The corneal nodules resolved with scarring after a period of treatment. In conclusion, corneal nodular lesions can be associated with various pathologies. Thorough history, examination, and appropriate investigations are needed to reveal the underlying causes. Serial anterior segment images and AS-OCT are useful to monitor progression and treatment response. Prompt diagnosis and initiation of treatment are crucial to prevent further complications.
  11. Maniam A, Chee Min L, Kiet Phang L, Vendargon FM, Othman O
    Cureus, 2021 Dec;13(12):e20769.
    PMID: 35111454 DOI: 10.7759/cureus.20769
    Keratomycosis is a significant cause of mono-ocular blindness, especially in tropical regions. Fungal keratitis developing in corneal incisions is very rare. We report the experience of treating two patients diagnosed with recalcitrant candida keratitis post-phacoemulsification with anterior chamber washout and deep debridement. The first patient was a 68-year-old woman who underwent left eye phacoemulsification nine months ago with a postoperative best corrected visual acuity of 6/6. The second patient was a 73-year-old man who had uneventful right eye phacoemulsification six months prior with a postoperative best corrected visual acuity of 6/9. Both patients used topical steroids postoperatively for more than three months and noted a drop in vision. Both patients had deep stromal infiltration and endothelial plaque at the primary corneal wound. They were unresponsive to topical, intracameral, and systemic antifungal therapy. Both patients underwent anterior chamber evacuation of hypopyon and endothelial plaque removal. Evacuation of hypopyon and removal of endothelial plaque was done with a 23G vitrectomy cutter using a low-powered vacuum controlled at 200 mmHg. The fluid inside the tubing was sent for culture analysis. We used viscoelastic coating on the endothelium to minimize the damage during the operations. Intracameral amphotericin B 15 µg/0.1 ml was given at the end of the operation. Postoperatively, both patients had clear corneas. The first patient's visual acuity improved 6/18, and the second patient's visual acuity improved to 6/9. Both cultures isolated Candida parapsilosis sensitive to amphotericin. These patient cases highlight that evacuation of the anterior chamber infiltration in recalcitrant fungal keratitis and intracameral injection of amphotericin B can be an effective adjuvant therapy.
  12. Yusof AMZ, Othman O, Tang SF, Hassan MR, Din NM
    Int J Ophthalmol, 2022;15(11):1782-1790.
    PMID: 36404967 DOI: 10.18240/ijo.2022.11.08
    AIM: To compare the diagnostic ability of glaucoma parameters measured by the optical coherence tomography (OCT) in normal, preperimetric glaucoma (PPG) and perimetric glaucoma (PG) patients.

    METHODS: This cross-sectional observational study includes 127 eyes of 127 subjects. Patients were divided into PPG (51 eyes), PG (46 eyes), and normal controls (30 eyes) based on clinical optic disc assessment and Humphrey visual field changes. The Heidelberg Spectralis OCT machine using Glaucoma Module Premium Edition software was used to measure the retinal nerve fiber layer (RNFL) and Bruch's membrane opening-minimum rim width (BMO-MRW) to assess the optic nerve head and ganglion cell layer (GCL) thickness in the macula.

    RESULTS: RNFL, MRW, and GCL thickness were all significantly thinner in PG compared to PPG and the normal group. The BMO-MRW parameters showed better specificity (>70%) at 90% specificity compared to both RNFL and GCL parameters to discriminate normal, PPG, and PG patients. All BMO-MRW parameters showed higher area under curves (AUC) compared to RNFL and GCL parameters with the highest AUC observed in the superotemporal sector of the BMO-MRW (AUC=0.819 and and 0.897 between normal and PPG and PG groups respectively).

    CONCLUSION: While the BMO-MRW best discriminates PPG and PG against normal eyes, GCL parameters poorly differentiate the three groups.

  13. Azal AB, Hussein SH, Tang SF, Othman O, Din NM
    Int J Ophthalmol, 2023;16(8):1243-1249.
    PMID: 37602343 DOI: 10.18240/ijo.2023.08.09
    AIM: To evaluate whether latanoprost/timolol fixed combination (LTFC) dosed twice daily may provide further intraocular pressure (IOP) reduction and evaluate the safety profile at this dose.

    METHODS: This is an open-labeled, randomized, prospective crossover study on fourty primary open angle glaucoma patients. Two weeks of washout period were followed by randomization to either once daily (OD, group A) or twice daily dosing (BD, group B) of LTFC for 4wk. After another 2-week washout period, the patients' treatment dose was crossed-over for another 4wk. IOP reduction alongside ocular and systemic side effects were evaluated.

    RESULTS: Mean baseline IOP was 18.57±2.93 and 17.8±3.01 mm Hg before OD and BD dose respectively, (P=0.27). Mean IOP after BD dose was statistically lower (12.49±1.59 mm Hg) compared to OD (13.48±1.81 mm Hg, P=0.017). Although IOP reduction after BD dose was more (5.32±3.24 mm Hg, 29.89%) than after OD dosing (5.04 mm Hg, 27.14%), it did not reach statistical significance (P=0.68). Patients switched from OD to BD (group A) showed mean IOP reduction by 0.69 mm Hg [95% confidence interval (CI): -0.09 to 1.48 mm Hg, P=0.078]; but patients switched from BD to OD (group B) had significantly higher mean IOP by 1.25 mm Hg (95%CI: -2.04 to -0.46 mm Hg, P=0.006). BD dose had more ocular side effects albeit mild.

    CONCLUSION: Mean IOP after LTFC dosed twice daily is statistically lower, with additional mild side effects.

  14. Mohammad Razali A, Tang SF, Syed Zakaria SZ, Che-Hamzah J, Aung T, Othman O, et al.
    Ophthalmic Res, 2023;66(1):854-861.
    PMID: 36917970 DOI: 10.1159/000530072
    INTRODUCTION: The aim of this study was to assess the effect of phacoemulsification and endo-cyclophotocoagulation (phaco-ECP) on intraocular pressure (IOP) fluctuation as assessed by the water drinking test (WDT) in primary open angle glaucoma (POAG).

    METHODS: This was a prospective observational study carried out at a tertiary referral centre. POAG patients on topical antiglaucoma medications and planned for phaco-ECP were recruited. WDT was performed before surgery and 6 weeks postoperatively by drinking 10 mL/kg of water in 5 min followed by serial IOP by Goldmann applanation tonometry measurements at 15, 30, 45, and 60 min. Mean IOP, IOP fluctuation (difference between highest and lowest IOP), IOP reduction, and factors affecting IOP fluctuation were analysed.

    RESULTS: Twenty eyes from 17 patients were included. Baseline IOP was similar before (14.7 ± 2.7 mm Hg) and after (14.8 ± 3.4 mm Hg, p = 0.90) surgery. There was no difference in mean IOP (17.6 ± 3.4 mm Hg vs. 19.3 ± 4.7 mm Hg pre- and postoperative, respectively, p = 0.26) or peak IOP (19.37 ± 3.74 mm Hg vs. 21.23 ± 5.29 mm Hg, p = 0.25), albeit a significant reduction in IOP-lowering medications (2.2 ± 1.15 vs. 0.35 ± 0.93, p < 0.001) postoperatively. IOP fluctuation was significantly greater (6.4 ± 3.2 mm Hg vs. 4.6 ± 2.1 mm Hg, p = 0.015) with more eyes having significant IOP fluctuation of ≥6 mm Hg (11 eyes [55%] vs. 4 eyes [20%], p < 0.001) postoperatively. Factors that were significantly associated with increased postoperative IOP fluctuations were higher preoperative IOP fluctuation (β = 0.69, 95% CI 0.379-1.582, p = 0.004) and more number of postoperative antiglaucoma medications (β = 0.627, 95% CI 0.614-3.322, p = 0.008).

    CONCLUSION: Reducing aqueous production with phaco-ECP does not eliminate IOP fluctuation in POAG patients. The increase in postoperative IOP fluctuation suggests increased outflow resistance after phaco-ECP.

  15. Cheng TC, Yahya MFN, Mohd Naffi AA, Othman O, Seng Fai T, Yong MH, et al.
    J Craniofac Surg, 2021 Oct 01;32(7):2285-2291.
    PMID: 33770023 DOI: 10.1097/SCS.0000000000007645
    BACKGROUND: To evaluate the satisfaction of surgeons and trainees with three-dimensional (3D) ophthalmic surgery during a demonstration compared to traditional surgery.

    METHODS: This validated questionnaire-based study was conducted over 1-month during which Ngenuity 3D surgery was demonstrated. All surgeons and trainees exposed were recruited to complete a questionnaire comprising visualization, physical, ease of use, teaching and learning, and overall satisfaction.

    RESULTS: All 7 surgeons and 33 postgraduate students responded. Surgeons reported no significant difference except overall (P = 0.047, paired t-test). Postgraduate trainees reported significantly better experience with 3D for illumination (P = 0.008), manoeuvrability (P = 0.01), glare (P = 0.037), eye strain (P = 0.008), neck and upper back strain (P = 0.000), lower back pain (P = 0.019), communication (P = 0.002), comfortable environment (P = 0.001), sharing of knowledge (P = 0.000), and overall (P = 0.009).

    CONCLUSIONS: During early experience, surgeons and trainees reported better satisfaction with 3D overall. Trainees had better satisfaction with 3D in various subcomponents of visualization, physical, ease of use, and education.

  16. Wong WM, Tham YC, Simunovic MP, Chen FK, Luu CD, Chen H, et al.
    Asia Pac J Ophthalmol (Phila), 2024;13(1):100030.
    PMID: 38233300 DOI: 10.1016/j.apjo.2023.100030
    PURPOSE: There are major gaps in our knowledge of hereditary ocular conditions in the Asia-Pacific population, which comprises approximately 60% of the world's population. Therefore, a concerted regional effort is urgently needed to close this critical knowledge gap and apply precision medicine technology to improve the quality of lives of these patients in the Asia-Pacific region.

    DESIGN: Multi-national, multi-center collaborative network.

    METHODS: The Research Standing Committee of the Asia-Pacific Academy of Ophthalmology and the Asia-Pacific Society of Eye Genetics fostered this research collaboration, which brings together renowned institutions and experts for inherited eye diseases in the Asia-Pacific region. The immediate priority of the network will be inherited retinal diseases (IRDs), where there is a lack of detailed characterization of these conditions and in the number of established registries.

    RESULTS: The network comprises 55 members from 35 centers, spanning 12 countries and regions, including Australia, China, India, Indonesia, Japan, South Korea, Malaysia, Nepal, Philippines, Singapore, Taiwan, and Thailand. The steering committee comprises ophthalmologists with experience in consortia for eye diseases in the Asia-Pacific region, leading ophthalmologists and vision scientists in the field of IRDs internationally, and ophthalmic geneticists.

    CONCLUSIONS: The Asia Pacific Inherited Eye Disease (APIED) network aims to (1) improve genotyping capabilities and expertise to increase early and accurate genetic diagnosis of IRDs, (2) harmonise deep phenotyping practices and utilization of ontological terms, and (3) establish high-quality, multi-user, federated disease registries that will facilitate patient care, genetic counseling, and research of IRDs regionally and internationally.

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