Displaying publications 21 - 30 of 30 in total

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  1. Jayallan B, Ngah NF, Hussain NI, Nik Jaafar NR, Aizuddin AN, Yong MH, et al.
    Cureus, 2023 May;15(5):e38423.
    PMID: 37273393 DOI: 10.7759/cureus.38423
    INTRODUCTION: During the COVID-19 pandemic, non-frontline medical disciplines, including ophthalmology, were advised to minimize their services to channel crucial healthcare resources to manage the surge in COVID-19 cases. The ophthalmology department postponed all non-urgent appointments and elective surgical procedures. However, little is known about the visual and mental health impact of these changes in ophthalmology services. Therefore, our study aimed to explore the impact of postponement in ophthalmology outpatient clinic appointments towards visual acuity (VA) changes and the psychological well-being of patients during the COVID-19 pandemic in Malaysia.

    METHODOLOGY: This cross-sectional study, utilizing a convenience sampling method, recruited patients attending ophthalmology outpatient clinic services from July 2020 to June 2021 to participate in the study. The Snellen chart was used to measure the VA, and the Kessler psychological distress scale (K-10) was used to measure psychological distress levels among patients with (study) and without (controls) postponement of the appointment.  Results: A total of 485 patients were included in the data analysis; 267 study and 218 controls. There is a statistically significant difference in categorical change of VA (p < 0.001) and categorical K-10 score (p = 0.048) among the study and control groups. Nonetheless, a decline in VA alone does not show a statistically significant association with an increased probability of experiencing psychological distress (p=0.149).

    CONCLUSION: Postponement of ophthalmology appointments negatively affected the VA and the psychological well-being of patients. Appropriate assessment of patients before postponing their appointment is crucial to mitigate the worsening of VA and psychological distress.

  2. 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.

  3. Lam C, Alsaeedi HA, Koh AE, Harun MHN, Hwei ANM, Mok PL, et al.
    Tissue Eng Regen Med, 2021 02;18(1):143-154.
    PMID: 33415670 DOI: 10.1007/s13770-020-00312-1
    BACKGROUND: Different methods have been used to inject stem cells into the eye for research. We previously explored the intravitreal route. Here, we investigate the efficacy of intravenous and subretinal-transplanted human dental pulp stem cells (DPSCs) in rescuing the photoreceptors of a sodium iodate-induced retinal degeneration model.

    METHODS: Three groups of Sprague Dawley rats were used: intervention, vehicle group and negative control groups (n = 6 in each). Intravenous injection of 60 mg/kg sodium iodate (day 0) induced retinal degeneration. On day 4 post-injection of sodium iodate, the rats in the intervention group received intravenous DPSC and subretinal DPSC in the right eye; rats in the vehicle group received subretinal Hank's balance salt solution and intravenous normal saline; while negative control group received nothing. Electroretinogram (ERG) was performed to assess the retinal function at day 0 (baseline), day 4, day 11, day 18, day 26, and day 32. By the end of the study at day 32, the rats were euthanized, and both their enucleated eyes were sent for histology.

    RESULTS: No significant difference in maximal ERG a-wave (p = 0.107) and b-wave, (p = 0.153) amplitude was seen amongst the experimental groups. However, photopic 30 Hz flicker amplitude of the study eye showed significant differences in the 3 groups (p = 0.032). Within the intervention group, there was an improvement in 30 Hz flicker ERG response of all 6 treated right eyes, which was injected with subretinal DPSC; while the 30 Hz flicker ERG of the non-treated left eyes remained flat. Histology showed improved outer nuclear layer thickness in intervention group; however, findings were not significant compared to the negative and vehicle groups.

    CONCLUSION: Combination of subretinal and intravenous injection of DPSCs may have potential to rescue cone function from a NaIO3-induced retinal injury model.

  4. Looi SY, Bastion MC, Leow SN, Luu CD, Hairul NMH, Ruhaslizan R, et al.
    Indian J Ophthalmol, 2022 Jan;70(1):201-209.
    PMID: 34937239 DOI: 10.4103/ijo.IJO_473_21
    Purpose: There are no effective treatments currently available for optic nerve transection injuries. Stem cell therapy represents a feasible future treatment option. This study investigated the therapeutic potential of human umbilical cord-derived mesenchymal stem cell (hUC-MSC) transplantation in rats with optic nerve injury.

    Methods: Sprague-Dawley (SD) rats were divided into three groups: a no-treatment control group (n = 6), balanced salt solution (BSS) treatment group (n = 6), and hUC-MSCs treatment group (n = 6). Visual functions were assessed by flash visual evoked potential (fVEP) at baseline, Week 3, and Week 6 after optic nerve crush injury. Right eyes were enucleated after 6 weeks for histology.

    Results: The fVEP showed shortened latency delay and increased amplitude in the hUC-MSCs treated group compared with control and BSS groups. Higher cellular density was detected in the hUC-MSC treated group compared with the BSS and control groups. Co-localized expression of STEM 121 and anti-S100B antibody was observed in areas of higher nuclear density, both in the central and peripheral regions.

    Conclusion: Peribulbar transplantation of hUC-MSCs demonstrated cellular integration that can potentially preserve the optic nerve function with a significant shorter latency delay in fVEP and higher nuclear density on histology, and immunohistochemical studies observed cell migration particularly to the peripheral regions of the optic nerve.

  5. Alsaeedi HA, Lam C, Koh AE, Teh SW, Mok PL, Higuchi A, et al.
    J. Photochem. Photobiol. B, Biol., 2020 Jan;203:111727.
    PMID: 31862637 DOI: 10.1016/j.jphotobiol.2019.111727
    Blindness and vision impairment are caused by irremediable retinal degeneration in affected individuals worldwide. Cell therapy for a retinal replacement can potentially rescue their vision, specifically for those who lost the light sensing photoreceptors in the eye. As such, well-characterized retinal cells are required for the replacement purposes. Stem cell-based therapy in photoreceptor and retinal pigment epithelium transplantation is well received, however, the drawbacks of retinal transplantation is the limited clinical protocols development, insufficient number of transplanted cells for recovery, the selection of potential stem cell sources that can be differentiated into the target cells, and the ability of cells to migrate to the host tissue. Dental pulp stem cells (DPSC) belong to a subset of mesenchymal stem cells, and are recently being studied due to its high capability of differentiating into cells of the neuronal lineage. In this review, we look into the potential uses of DPSC in treating retinal degeneration, and also the current data supporting its application.
  6. Koh AE, Alsaeedi HA, Rashid MBA, Lam C, Harun MHN, Saleh MFBM, et al.
    J. Photochem. Photobiol. B, Biol., 2019 Jul;196:111514.
    PMID: 31154277 DOI: 10.1016/j.jphotobiol.2019.111514
    Retinal disorders account for a large proportion of ocular disorders that can lead to visual impairment or blindness, and yet our limited knowledge in the pathogenesis and choice of appropriate animal models for new treatment modalities may contribute to ineffective therapies. Although genetic in vivo models are favored, the variable expressivity and penetrance of these heterogeneous disorders can cause difficulties in assessing potential treatments against retinal degeneration. Hence, an attractive alternative is to develop a chemically-induced model that is both cost-friendly and standardizable. Sodium iodate is an oxidative chemical that is used to simulate late stage retinitis pigmentosa and age-related macular degeneration. In this study, retinal degeneration was induced through systemic administration of sodium iodate (NaIO3) at varying doses up to 80 mg/kg in Sprague-Dawley rats. An analysis on the visual response of the rats by electroretinography (ERG) showed a decrease in photoreceptor function with NaIO3 administration at a dose of 40 mg/kg or greater. The results correlated with the TUNEL assay, which revealed signs of DNA damage throughout the retina. Histomorphological analysis also revealed extensive structural lesions throughout the outer retina and parts of the inner retina. Our results provided a detailed view of NaIO3-induced retinal degeneration, and showed that the administration of 40 mg/kg NaIO3 was sufficient to generate disturbances in retinal function. The pathological findings in this model reveal a degenerating retina, and can be further utilized to develop effective therapies for RPE, photoreceptor, and bipolar cell regeneration.
  7. Koh AE, Alsaeedi HA, Rashid MBA, Lam C, Harun MHN, Ng MH, et al.
    Front Cell Dev Biol, 2021;9:652017.
    PMID: 33987180 DOI: 10.3389/fcell.2021.652017
    Mesenchymal stem cells (MSC) are highly regarded as a potential treatment for retinal degenerative disorders like retinitis pigmentosa and age-related macular degeneration. However, donor cell heterogeneity and inconsistent protocols for transplantation have led to varied outcomes in clinical trials. We previously showed that genetically-modifying MSCs to express erythropoietin (MSCEPO) improved its regenerative capabilities in vitro. Hence, in this study, we sought to prove its potential in vivo by transplanting MSCsEPO in a rat retinal degeneration model and analyzing its retinal transcriptome using RNA-Seq. Firstly, MSCsEPO were cultured and expanded before being intravitreally transplanted into the sodium iodate-induced model. After the procedure, electroretinography (ERG) was performed bi-weekly for 30 days. Histological analyses were performed after the ERG assessment. The retina was then harvested for RNA extraction. After mRNA-enrichment and library preparation, paired-end RNA-Seq was performed. Salmon and DESeq2 were used to process the output files. The generated dataset was then analyzed using over-representation (ORA), functional enrichment (GSEA), and pathway topology analysis tools (SPIA) to identify enrichment of key pathways in the experimental groups. The results showed that the MSCEPO-treated group had detectable ERG waves (P <0.05), which were indicative of successful phototransduction. The stem cells were also successfully detected by immunohistochemistry 30 days after intravitreal transplantation. An initial over-representation analysis revealed a snapshot of immune-related pathways in all the groups but was mainly overexpressed in the MSC group. A subsequent GSEA and SPIA analysis later revealed enrichment in a large number of biological processes including phototransduction, regeneration, and cell death (P adj <0.05). Based on these pathways, a set of pro-survival gene expressions were extracted and tabulated. This study provided an in-depth transcriptomic analysis on the MSCEPO-treated retinal degeneration model as well as a profile of pro-survival genes that can be used as candidates for further genetic enhancement studies on stem cells.
  8. Alsaeedi HA, Koh AE, Lam C, Rashid MBA, Harun MHN, Saleh MFBM, et al.
    J. Photochem. Photobiol. B, Biol., 2019 Sep;198:111561.
    PMID: 31352000 DOI: 10.1016/j.jphotobiol.2019.111561
    Blindness and vision loss contribute to irreversible retinal degeneration, and cellular therapy for retinal cell replacement has the potential to treat individuals who have lost light sensitive photoreceptors in the retina. Retinal cells are well characterized in function, and are a subject of interest in cellular replacement therapy of photoreceptors and the retinal pigment epithelium. However, retinal cell transplantation is limited by various factors, including the choice of potential stem cell source that can show variability in plasticity as well as host tissue integration. Dental pulp is one such source that contains an abundance of stem cells. In this study we used dental pulp-derived mesenchymal stem cells (DPSCs) to mitigate sodium iodate (NaIO3) insult in a rat model of retinal degeneration. Sprague-Dawley rats were first given an intravitreal injection of 3 × 105 DPSCs as well as a single systemic administration of NaIO3 (40 mg/kg). Electroretinography (ERG) was performed for the next two months and was followed-up by histological analysis. The ERG recordings showed protection of DPSC-treated retinas within 4 weeks, which was statistically significant (* P ≤ .05) compared to the control. Retinal thickness of the control was also found to be thinner (*** P ≤ .001). The DPSCs were found integrated in the photoreceptor layer through immunohistochemical staining. Our findings showed that DPSCs have the potential to moderate retinal degeneration. In conclusion, DPSCs are a potential source of stem cells in the field of eye stem cell therapy due to its protective effects against retinal degeneration.
  9. 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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