Displaying publications 1 - 20 of 94 in total

Abstract:
Sort:
  1. Ransangan J, Manin BO
    Vet Microbiol, 2010 Sep 28;145(1-2):153-7.
    PMID: 20427132 DOI: 10.1016/j.vetmic.2010.03.016
    Culture of Asian seabass, Lates calcarifer (Bloch) is a popular aquaculture activity in Malaysia. This fish is in high demand and fetches a good price in the local market. The seed for this fish is commercially produced by induced spawning in hatcheries. However, the seed supply is affected by frequent mass mortality of larvae aged between 15 and 60 dph. The clinical signs shown by the affected larvae include lethargy, loss of appetite, uncoordinated swimming, unusual spiral movement pattern and dark coloration. Histological examination of brain and eye of the affected specimens revealed extensive cell vacuolation in larvae aged 15-25 dph. Partial nucleotide sequence of the nervous necrosis virus coat protein gene of the affected larvae showed 94.0-96.1% homology to the nucleotide sequences of coat protein gene from nervous necrosis virus isolated from other countries in the Southeast Asia and Australia. This study provides scientific evidence based on molecular technique that many episodes of mass mortality in seabass larvae in Sabah is associated with the viral nervous necrosis. Because no effective treatment has been reported for this infection, stringent biosecurity measures must be adopted for exclusion of the pathogen from the culture system.
    Matched MeSH terms: Retina/pathology; Retina/virology
  2. Aliahmad B, Kumar DK, Hao H, Unnikrishnan P, Che Azemin MZ, Kawasaki R, et al.
    ScientificWorldJournal, 2014;2014:467462.
    PMID: 25485298 DOI: 10.1155/2014/467462
    Fractal dimensions (FDs) are frequently used for summarizing the complexity of retinal vascular. However, previous techniques on this topic were not zone specific. A new methodology to measure FD of a specific zone in retinal images has been developed and tested as a marker for stroke prediction. Higuchi's fractal dimension was measured in circumferential direction (FDC) with respect to optic disk (OD), in three concentric regions between OD boundary and 1.5 OD diameter from its margin. The significance of its association with future episode of stroke event was tested using the Blue Mountain Eye Study (BMES) database and compared against spectrum fractal dimension (SFD) and box-counting (BC) dimension. Kruskal-Wallis analysis revealed FDC as a better predictor of stroke (H = 5.80, P = 0.016, α = 0.05) compared with SFD (H = 0.51, P = 0.475, α = 0.05) and BC (H = 0.41, P = 0.520, α = 0.05) with overall lower median value for the cases compared to the control group. This work has shown that there is a significant association between zone specific FDC of eye fundus images with future episode of stroke while this difference is not significant when other FD methods are employed.
    Matched MeSH terms: Retina/pathology*; Retinal Vessels/pathology
  3. Tajunisah I, Patel DK
    N Engl J Med, 2009 Aug 27;361(9):899.
    PMID: 19710488 DOI: 10.1056/NEJMicm0802683
    Matched MeSH terms: Retina/pathology*; Retinal Detachment/etiology*; Retinal Detachment/pathology
  4. Eu-sen VO
    Med J Malaya, 1969 Sep;24(1):18-20.
    PMID: 4243836
    Matched MeSH terms: Retina*
  5. Cheng RW, Yusof F, Tsui E, Jong M, Duffin J, Flanagan JG, et al.
    J Physiol, 2016 Feb 01;594(3):625-40.
    PMID: 26607393 DOI: 10.1113/JP271182
    KEY POINTS: Vascular reactivity, the response of the vessels to a vasoactive stimulus such as hypoxia and hyperoxia, can be used to assess the vascular range of adjustment in which the vessels are able to compensate for changes in PO2. Previous studies in the retina have not accurately quantified retinal vascular responses and precisely targeted multiple PaO2 stimuli at the same time as controlling the level of carbon dioxide, thus precluding them from modelling the relationship between retinal blood flow and oxygen. The present study modelled the relationship between retinal blood flow and PaO2, showing them to be a combined linear and hyperbolic function. This model demonstrates that the resting tonus of the vessels is at the mid-point and that they have great vascular range of adjustment, compensating for decreases in oxygen above a PETCO2 of 32-37 mmHg but being limited below this threshold. Retinal blood flow (RBF) increases in response to a reduction in oxygen (hypoxia) but decreases in response to increased oxygen (hyperoxia). However, the relationship between blood flow and the arterial partial pressure of oxygen has not been quantified and modelled in the retina, particularly in the vascular reserve and resting tonus of the vessels. The present study aimed to determine the limitations of the retinal vasculature by modelling the relationship between RBF and oxygen. Retinal vascular responses were measured in 13 subjects for eight different blood gas conditions, with the end-tidal partial pressure of oxygen (PETCO2) ranging from 40-500 mmHg. Retinal vascular response measurements were repeated twice; using the Canon laser blood flowmeter (Canon Inc., Tokyo, Japan) during the first visit and using Doppler spectral domain optical coherence tomography during the second visit. We determined that the relationship between RBF and PaO2 can be modelled as a combination of hyperbolic and linear functions. We concluded that RBF compensated for decreases in arterial oxygen content for all stages of hypoxia used in the present study but can no longer compensate below a PETCO2 of 32-37 mmHg. These vessels have a great vascular range of adjustment, increasing diameter (8.5% arteriolar and 21% total venous area) with hypoxia (40 mmHg P ETC O2; P < 0.001) and decreasing diameter (6.9% arteriolar and 23% total venous area) with hyperoxia (500 mmHg PETCO2; P < 0.001) to the same extent. This indicates that the resting tonus is near the mid-point of the adjustment ranges at resting PaO2 where sensitivity is maximum.
    Matched MeSH terms: Retina/physiology*; Retinal Vessels/physiology*
  6. Soe HJ, Khan AM, Manikam R, Samudi Raju C, Vanhoutte P, Sekaran SD
    J Gen Virol, 2017 Dec;98(12):2993-3007.
    PMID: 29182510 DOI: 10.1099/jgv.0.000981
    Plasma leakage is the main pathophysiological feature in severe dengue, resulting from altered vascular barrier function associated with an inappropriate immune response triggered upon infection. The present study investigated functional changes using an electric cell-substrate impedance sensing system in four (brain, dermal, pulmonary and retinal) human microvascular endothelial cell (MEC) lines infected with purified dengue virus, followed by assessment of cytokine profiles and the expression of inter-endothelial junctional proteins. Modelling of changes in electrical impedance suggests that vascular leakage in dengue-infected MECs is mostly due to the modulation of cell-to-cell interactions, while this loss of vascular barrier function observed in the infected MECs varied between cell lines and DENV serotypes. High levels of inflammatory cytokines (IL-6 and TNF-α), chemokines (CXCL1, CXCL5, CXCL11, CX3CL1, CCL2 and CCL20) and adhesion molecules (VCAM-1) were differentially produced in the four infected MECs. Further, the tight junctional protein, ZO-1, was down-regulated in both the DENV-1-infected brain and pulmonary MECs, while claudin-1, PECAM-1 and VE-cadherin were differentially expressed in these two MECs after infection. Non-purified virus stock was also studied to investigate the impact of virus stock purity on dengue-specific immune responses, and the results suggest that virus stock propagated through cell culture may include factors that mask or alter the DENV-specific immune responses of the MECs. The findings of the present study show that high DENV load differentially modulates human microvascular endothelial barrier function and disrupts the function of inter-endothelial junctional proteins during early infection with organ-specific cytokine production.
    Matched MeSH terms: Retina/cytology; Retina/immunology; Retina/virology
  7. Mohd Lazaldin MA, Iezhitsa I, Agarwal R, Bakar NS, Agarwal P, Mohd Ismail N
    Int J Neurosci, 2018 Oct;128(10):952-965.
    PMID: 29488424 DOI: 10.1080/00207454.2018.1446953
    PURPOSE: Amyloid beta (Aβ) is known to contribute to the pathophysiology of retinal neurodegenerative diseases such as glaucoma. Effects of intravitreal Aβ(1-42) on retinal and optic nerve morphology in animal models have widely been studied but not those of Aβ(1-40). Hence, we evaluated the time- and dose-related effects of intravitreal Aβ(1-40) on retinal and optic nerve morphology. Since oxidative stress and brain derived neurotrophic factor (BDNF) are associated with Aβ-induced neuronal damage, we also studied dose and time-related effects of Aβ(1-40) on retinal oxidative stress and BDNF levels.

    MATERIALS AND METHODS: Five groups of rats were intravitreally administered with vehicle or Aβ(1-40) in doses of 1.0, 2.5, 5 and 10 nmol. Animals were sacrificed and eyes were enucleated at weeks 1, 2 and 4 post-injection. The retinae were subjected to morphometric analysis and TUNEL staining. Optic nerve sections were stained with toluidine blue and were graded for neurodegenerative effects. The estimation of BDNF and markers of oxidative stress in retina were done using ELISA technique.

    RESULTS AND CONCLUSIONS: It was observed that intravitreal Aβ(1-40) causes significant retinal and optic nerve damage up to day 14 post-injection and there was increasing damage with increase in dose. However, on day 30 post-injection both the retinal and optic nerve morphology showed a trend towards normalization. The observations made for retinal cell apoptosis, retinal glutathione, superoxide dismutase activity and BDNF were in accordance with those of morphological changes with deterioration till day 14 and recovery by day 30 post-injection. The findings of this study may provide a guide for selection of appropriate experimental conditions for future studies.

    Matched MeSH terms: Retina
  8. Sukumaran K
    Br J Ophthalmol, 1991 Mar;75(3):179-80.
    PMID: 2012789
    A case of Norrie's disease in an identical twins is reported. No positive family history was obtained. The couple had no other children. The older of the twins died at the age of 9 months of uncertain cause. To the best of my knowledge this is the first case of Norrie's disease reported in Malaysia. And its occurrence in an identical twins is very rare.
    Matched MeSH terms: Retina/abnormalities*; Retina/pathology; Retinal Detachment/congenital; Retinal Detachment/pathology
  9. Ong Chin Feng W, Wan Hitam WH
    Taiwan J Ophthalmol, 2020 06 20;10(3):189-196.
    PMID: 33110750 DOI: 10.4103/tjo.tjo_22_20
    Purpose: Peripapillary retinal nerve fibre layer (RNFL) thickness might be useful in monitoring ongoing subclinical structural damage especially in eyes with no history of optic neuritis (ON) in neuromyelitis optica (NMO).

    Objective: To evaluate the peripapillary RNFL thickness and optic nerve functions in fellow eye of NMO with unilateral optic neuritis.

    Materials and Methods: A comparative cross-sectional study was conducted in 2 tertiary hospitals from August 2017 to May 2019. RNFL thickness and optic nerve functions were evaluated. Statistical analysis was performed using Statistical Package for Social Science version 24.

    Results: A total of 26 NMO patients and 26 controls were involved in this study. The median age (IQR) of NMO patients was 32.5 (12) years old. The RNFL thickness was significantly reduced in NMO patients with non-ON eyes as compared to control group. Best corrected visual acuity between the 2 groups were comparable (0.20 vs 0.00, p=0.071). Contrast sensitivity was also reduced in NMO patients (non-ON eyes) at all 5 spatial frequencies. In NMO group, 34.6% have normal colour vision. The mean deviation (MD) of Humphrey visual field (HVF) was higher in NMO group (p<0.001). There was a moderate correlation between RNFL thickness and contrast sensitivity. Weak correlation was found between the RNFL thickness with visual acuity and mean deviation of visual field test.

    Conclusion: Our study showed that the fellow eye of NMO patients with unilateral ON revealed a significant reduction in RNFL thickness and all the optic nerve functions have subtle early changes that signify a subclinical retinal damage.

    Matched MeSH terms: Retina
  10. Ling KP, Wu AL, Lai CC, Wu WC
    Taiwan J Ophthalmol, 2019 1 15;8(4):249-252.
    PMID: 30637197 DOI: 10.4103/tjo.tjo_100_18
    We report a case with multiple recurrences of retinal detachment (RD) with severe proliferative vitreoretinopathy in a 12-year-old child who underwent vitrectomy using a heavy liquid perfluoro-n-octane (PFO) as a short-term postoperative tamponade. He had an encircling band and three vitrectomies with gas, followed by silicone oil tamponade for retinal redetachment prior to the use of PFO as a short-term tamponade. Short-term PFO tamponade was used in which inferior retinal reattachment was considered to be difficult with conventional gas or silicone oil tamponade, especially in regard to proper postoperative posturing. The PFO was left in the eye for 1 week, and the retina remained reattached after removal of the PFO which was replaced with silicone oil tamponade in this case. PFO appears feasible and tolerable as a short-term postoperative tamponade in the management of complex pediatric RD.
    Matched MeSH terms: Retina; Retinal Detachment
  11. Allinjawi K, Kaur S, Akhir SM, Mutalib HA
    Saudi J Ophthalmol, 2020 12 28;34(2):94-100.
    PMID: 33575529 DOI: 10.4103/1319-4534.305035
    PURPOSE: The purpose was to determine the minimum near-addition power needed using Proclear® multifocal D-Design contact lens (adds: +1.50 D, +2.50 D, +3.00 D, and +3.50 D) to invert the pattern of relative hyperopic defocus in the peripheral retina into relative myopic defocus among the eyes of myopic schoolchildren.

    METHODS: Twenty-seven right eyes (24 females and 3 males) of 27 myopic schoolchildren aged between 13 and 15 years were included in this study. The measurements of central refraction, peripheral refraction (between 35° temporal and 35° nasal visual field in 5° steps), and lag of accommodation were conducted using the Grand-Seiko WR-5100K open-field autorefractometer initially without correction (WC), followed by with correction using four different addition powers of Proclear® multifocal D-Design contact lens in random sequence. Axial length was measured using a handheld probe ultrasound A-scan (Tomey AL-2000).

    RESULTS: The relative peripheral refractive error showed high hyperopic defocus of +1.08 ± 1.24 D at 35° nasal and +1.06 ± 1.06 D at 35° temporal visual field WC. All Proclear multifocal contact lenses (MFCLs) decreased the peripheral hyperopic defocus with increasing addition powers (F [2.938, 47.001] = 13.317, P < 0.001). However, only +3.00 D addition and +3.50 D addition (P = 0.001) could invert the peripheral hyperopic defocus into peripheral myopic defocus. Apart from that, the +3.00 D addition lens showed the lowest lag of accommodation (+1.10 ± 0.83 D) among the other MFCL adds (P = 0.002).

    CONCLUSION: A +3.00 D addition Proclear MFCL is the optimal addition power that can invert the pattern of peripheral hyperopic defocus into myopic defocus.

    Matched MeSH terms: Retina
  12. Ahmad SS
    Saudi J Ophthalmol, 2017 Jan-Mar;31(1):38-41.
    PMID: 28337061 DOI: 10.1016/j.sjopt.2016.08.001
    Glaucoma is a multi-factorial neurodegenerative disorder. The common denominator in all types of glaucomas is retinal ganglion cell death through apoptosis. However, this cellular demise in glaucoma is detected late by structural or functional analyses. There can be a 10-year delay prior to the appearance of visual field defects and pre-perimetric glaucoma is an issue still being addressed. However, a new cutting-edge technology called detection of apoptosing retinal cells (DARC) is being developed. This technique is capable of non-invasive, real-time visualization of apoptotic changes at the cellular level. It can detect glaucomatous cell damage at a very early stage, at the moment apoptosis starts, and thus management can be initiated even prior to development of visual field changes. In future, this technique will also be able to provide conclusive evidence of the effectiveness of treatment protocol and the need for any modifications which may be required. This article aims to provide a concise review of DARC technology.
    Matched MeSH terms: Retina; Retinal Ganglion Cells
  13. Lim AK, Alexander SM, Lim KS
    Retina, 2009 Jan;29(1):112-6.
    PMID: 18784619 DOI: 10.1097/IAE.0b013e318187f14a
    Matched MeSH terms: Retina/surgery*; Retinal Detachment/surgery*
  14. Koh A, Lai TYY, Wei WB, Mori R, Wakiyama H, Park KH, et al.
    Retina, 2020 Aug;40(8):1529-1539.
    PMID: 31385918 DOI: 10.1097/IAE.0000000000002624
    PURPOSE: To evaluate the real-world effectiveness and safety of intravitreal ranibizumab 0.5 mg in treatment-naive patients with and without polypoidal choroidal vasculopathy (PCV).

    METHODS: Assessment of neovascular age-related macular degeneration patients with or without PCV after 12 months of ranibizumab treatment during the LUMINOUS study. Outcome measures were visual acuity and central retinal thickness changes from baseline and the rate of ocular adverse events.

    RESULTS: At baseline, 572 and 5,644 patients were diagnosed with and without PCV, respectively. The mean visual acuity gain from baseline at Month 12 in the PCV and non-PCV groups was +5.0 and +3.0 letters, respectively; these gains were achieved with a mean of 4.4 and 5.1 ranibizumab injections. Eighty percent of PCV patients and 72.2% of non-PCV patients who had baseline visual acuity ≥73 letters maintained this level of vision at Month 12; 20.6% and 17.9% of patients with baseline visual acuity <73 letters achieved visual acuity ≥73 letters in these groups. Greater reductions in central retinal thickness from baseline were also observed for the PCV group versus the non-PCV group. The rate of serious ocular adverse events was 0.7% (PCV group) and 0.9% (non-PCV group).

    CONCLUSION: LUMINOUS confirms the effectiveness and safety of ranibizumab in treatment-naive patients with PCV.

    Matched MeSH terms: Retina
  15. Chou HD, Teh WM, Wu WC, Hwang YS, Chen KJ, Lai CC
    Retina, 2023 Dec 01;43(12):2134-2138.
    PMID: 35512285 DOI: 10.1097/IAE.0000000000003516
    PURPOSE: To report the outcomes of the Peeling and Internal Limiting Membrane Reposition (PAIR) technique in myopic foveoschisis.

    METHODS: A retrospective case series of eyes with myopic foveoschisis that underwent vitrectomy and PAIR. Visual acuity, fundus photographs, and optical coherence tomography measurements were obtained and analyzed. Data are presented as medians (ranges).

    RESULTS: A total of seven eyes underwent PAIR and were followed up for 339 days (188-436 days). No intraoperative complications were noted. One eye exhibited postoperative macular hole formation, but the hole was healed through fluid-gas exchange. At the last follow-up, the visual acuity had improved from 20/66 (20/332-20/40) to 20/40 (20/100-20/25), and the central foveal thickness had decreased from 576 µ m to 269 µ m. A repositioned internal limiting membrane (ILM) was observed in six of the eyes, and inner retinal dimples were noted in only two eyes. However, retinal wrinkles under the repositioned or perifoveal ILM were noted in five eyes.

    CONCLUSION: The PAIR technique relieved traction, restored the ILM, and achieved functional and morphological improvement in eyes with myopic foveoschisis. Limited occurrence of inner retinal dimples and retinal thinning was noted, but retinal wrinkles occurred, likely due to ILM contracture.

    Matched MeSH terms: Retina/surgery; Epiretinal Membrane*
  16. Paraoan L, Sharif U, Carlsson E, Supharattanasitthi W, Mahmud NM, Kamalden TA, et al.
    Prog Retin Eye Res, 2020 11;79:100859.
    PMID: 32278708 DOI: 10.1016/j.preteyeres.2020.100859
    Secretory proteostasis integrates protein synthesis, processing, folding and trafficking pathways that are essential for efficient cellular secretion. For the retinal pigment epithelium (RPE), secretory proteostasis is of vital importance for the maintenance of the structural and functional integrity of apical (photoreceptors) and basal (Bruch's membrane/choroidal blood supply) sides of the environment it resides in. This integrity is achieved through functions governed by RPE secreted proteins, which include extracellular matrix modelling/remodelling, angiogenesis and immune response modulation. Impaired RPE secretory proteostasis affects not only the extracellular environment, but leads to intracellular protein aggregation and ER-stress with subsequent cell death. Ample recent evidence implicates dysregulated proteostasis as a key factor in the development of age-related macular degeneration (AMD), the leading cause of blindness in the developed world, and research aiming to characterise the roles of various proteins implicated in AMD-associated dysregulated proteostasis unveiled unexpected facets of the mechanisms involved in degenerative pathogenesis. This review analyses cellular processes unveiled by the study of the top 200 transcripts most abundantly expressed by the RPE/choroid in the light of the specialised secretory nature of the RPE. Functional roles of these proteins and the mechanisms of their impaired secretion, due to age and genetic-related causes, are analysed in relation to AMD development. Understanding the importance of RPE secretory proteostasis in relation to maintaining retinal health and how it becomes impaired in disease is of paramount importance for the development and assessment of future therapeutic advancements involving gene and cell therapies.
    Matched MeSH terms: Retina/metabolism*; Retina/pathology; Retinal Pigment Epithelium/metabolism*; Retinal Pigment Epithelium/pathology
  17. Leow SN, Luu CD, Hairul Nizam MH, Mok PL, Ruhaslizan R, Wong HS, et al.
    PLoS One, 2015;10(6):e0128973.
    PMID: 26107378 DOI: 10.1371/journal.pone.0128973
    To investigate the safety and efficacy of subretinal injection of human Wharton's Jelly-derived mesenchymal stem cells (hWJ-MSCs) on retinal structure and function in Royal College of Surgeons (RCS) rats.
    Matched MeSH terms: Retina/metabolism; Retina/pathology*; Retinal Degeneration/metabolism; Retinal Degeneration/pathology; Retinal Degeneration/therapy*
  18. Chung KM
    Optom Vis Sci, 1999 Feb;76(2):121-6.
    PMID: 10082059
    The clinical significance of fundus magnification produced during direct ophthalmoscopy of the corrected eye has not been fully established. Based on paraxial ray tracing, fundus magnification (M) can be defined by a simple equation, M = (K'/4) x (Fs/K), where K' is the dioptric axial power of the eye, Fs is the correcting thin lens power and K is the ocular ametropia. Refractive myopes produce greater fundus magnification than axial myopes, whereas refractive hyperopes produce lower fundus magnification than axial hyperopes. If we assume 15 x fundus magnification as our standard magnification for an emmetropic reduced eye, then wearing glasses or putting the focusing lens at or close to the anterior focus of the eye is able to achieve the standard magnification for axial myope and axial hyperope, whereas wearing contact lenses is able to achieve the standard magnification for refractive myope and refractive hyperope. Vertex distance has greater influence on fundus magnification produced during direct ophthalmoscopy than other funduscopic techniques. In conclusion, the newly defined formula has clinical applications during direct ophthalmoscopy.
    Matched MeSH terms: Retina/pathology*
  19. Chen KJ, Chou HD, Teh WM
    Ophthalmol Retina, 2019 10;3(10):887.
    PMID: 31585711 DOI: 10.1016/j.oret.2019.05.023
    Matched MeSH terms: Retina/pathology*
  20. Ahmad SS, Ghani SA
    Oman J Ophthalmol, 2012 May;5(2):115-7.
    PMID: 22993469
    Kearns-Sayre syndrome (KSS) belongs to the group of neuromuscular disorders known as mitochondrial encephalomyopathies. It has characteristic syndromal features, which include: chronic progressive external ophthalmoplegia, bilateral atypical pigmentary retinopathy, and cardiac conduction abnormalities. So far, only a single case has been reported where a patient with KSS had a normal retina. Herein, we report this extremely rare variant of KSS, which not only presented later than the normal age of presentation, but also had minimal pigmentary retinopathy.
    Matched MeSH terms: Retina
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links