Displaying publications 1 - 20 of 94 in total

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  1. Kandiah R, Annuar Z, Sukumaran K
    Family Physician, 1989;1:60-63.
    Matched MeSH terms: Retina
  2. Chaikitmongkol V, Sagong M, Lai TYY, Tan GSW, Ngah NF, Ohji M, et al.
    Asia Pac J Ophthalmol (Phila), 2021 Nov 24;10(6):507-518.
    PMID: 34839342 DOI: 10.1097/APO.0000000000000445
    PURPOSE: Review and provide consensus recommendations on use of treat-and-extend (T&E) regimens for neovascular age-related macular degeneration (nAMD) and polypoidal choroidal vasculopathy (PCV) management with relevance for clinicians in the Asia-Pacific region.

    METHODS: A systematic search of MEDLINE, EMBASE, and Cochrane databases, and abstract databases of the Asia-Pacific Vitreo-retina Society, European Society of Retina Specialists, American Academy of Ophthalmology, and Controversies in Ophthalmology: Asia-Australia congresses, was conducted to assess evidence for T&E regimens in nAMD. Only studies with ≥100 study eyes were included. An expert panel reviewed the results and key factors potentially influencing the use of T&E regimens in nAMD and PCV, and subsequently formed consensus recommendations for their application in the Asia-Pacific region.

    RESULTS: Twenty-seven studies were included. Studies demonstrated that T&E regimens with aflibercept, ranibizumab, or bevacizumab in nAMD, and with aflibercept in PCV, were efficacious and safe. The recommendation for T&E is, after ≥3 consecutive monthly loading doses, treatment intervals can be extended by 2 to 4 weeks up to 12 to 16 weeks. When disease activity recurs, the recommendation is to reinject and shorten intervals by 2 to 4 weeks until fluid resolution, after which treatment intervals can again be extended. Intraretinal fluid should be treated until resolved; however, persistent minimal subretinal fluid after consecutive treatments may be tolerated with treatment intervals maintained or extended if the clinical condition is stable.

    CONCLUSIONS: T&E regimens are efficacious and safe for nAMD and PCV, can reduce the number of visits, and minimize the overall burden for clinicians and patients.

    Matched MeSH terms: Retina
  3. 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
  4. Norhani Mohidin, Shaznida Ghulam, Rokiah Omar
    MyJurnal
    Elektroretinogram paten (pERG) adalah pengrekodan respons retina terhadap stimulus paten yang dipancarkan bersilih ganti. Ia memberi maklumat mengenai integriti sel dalaman retina khasnya sel ganglion. Pengrekodan pERG dalam sesebuah makmal boleh dipengaruhi oleh beberapa faktor, maka piawai makmal perlu ada untuk memastikan bacaan pERG yang diperolehi boleh diulang dan dihasilkan semula. Objektif kajian ini ialah untuk menentusahkan faktor yang mungkin mempengaruhi pengukuran pERG untuk paiwaian Makmal Elektrofisiologi Jabatan Optometri, Fakulti Sains Kesihatan (FSK), Universiti Kebangsaan Malaysia (UKM). Kajian ini melibatkan 45 orang subjek yang berumur di antara 20 hingga 25 tahun yang dibahagikan kepada 3 kumpulan. Faktor yang dikaji adalah 1) kesan penggunaan anestetik Alcaine 0.5%, 2) variasi pengukuran pada waktu pagi dan petang dan 3) saiz dan bentuk target fiksasi yang berbeza terhadap bacaan pERG (amplitud dan tempoh pendam). Ujian-t berpasangan mendapati tiada perbezaan yang signifikan antara pengukuran sebelum dan selepas penggunaan Alcaine 0.5% bagi amplitud (p = 0.116) dan tempoh pendam
    (p = 0.557). Pengukuran pada waktu pagi dan petang juga menunjukkan tiada perbezaan signifikan bagi amplitud (p = 0.864) dan tempoh pendam (p = 0.174). Untuk bentuk dan saiz target yang berbeza, didapati tiada perbezaan yang signifikan untuk parameter amplitud (p = 0.125) dan tempoh pendam (p = 0.404). Kesimpulannya, penggunaan Alcaine 0.5%, pengukuran pada waktu pagi dan petang dan target fiksasi yang berbeza tidak mempengaruhi bacaan pERG di Makmal Elektrofisiologi, FSK, UKM. Hasil kajian boleh diguna pakai untuk perbandingan dalam penyelidikan ataupun tujuan pendiagnosan penyakit retina di masa hadapan.


    Matched MeSH terms: Retina; Retinal Ganglion Cells
  5. Noor Aniah, A., Bastion, M.L.C., Mushawiahti, M.
    MyJurnal
    Retinal detachment is one of the common complications of pathological myopia due to presence of retinal break.
    However, retinal break commonly occurs in the peripheral retina. This case report illustrates the rare incidence of
    retinal break adjacent to the optic disc, highlights the possible causes of poor visual outcome following surgical
    repair as well as the possible measures to treat the complications.
    Matched MeSH terms: Retina; Retinal Detachment; Retinal Perforations
  6. Ibrahim N, Sakinah Z, Abdul Ghani Z, Ibrahim M
    Cureus, 2019 Mar 27;11(3):e4335.
    PMID: 31187000 DOI: 10.7759/cureus.4335
    Choroidal melanoma is an uncommon malignant melanoma among non-Caucasians. We report here a case of a high myope patient who presented with symptoms of acute retinal detachment, which had been diagnosed as possible rhegmatogenous retinal detachment from the initial assessment. A detailed vitreoretinal evaluation revealed a glimpse of an obscured intraocular mass underneath the detached retina, which later proved to be a choroidal melanoma. This is an unexpected cause of retinal detachment in a myopic eye. Furthermore, the rare nature of choroidal melanoma in this particular region of the world makes this an ignored diagnosis at presentation.
    Matched MeSH terms: Retina; Retinal Detachment
  7. 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.
    Matched MeSH terms: Retina/drug effects*; Retina/pathology; Retina/physiology; Retinal Degeneration/pathology*
  8. Ramli R, Idris MYI, Hasikin K, A Karim NK, Abdul Wahab AW, Ahmedy I, et al.
    J Healthc Eng, 2017;2017:1489524.
    PMID: 29204257 DOI: 10.1155/2017/1489524
    Retinal image registration is important to assist diagnosis and monitor retinal diseases, such as diabetic retinopathy and glaucoma. However, registering retinal images for various registration applications requires the detection and distribution of feature points on the low-quality region that consists of vessels of varying contrast and sizes. A recent feature detector known as Saddle detects feature points on vessels that are poorly distributed and densely positioned on strong contrast vessels. Therefore, we propose a multiresolution difference of Gaussian pyramid with Saddle detector (D-Saddle) to detect feature points on the low-quality region that consists of vessels with varying contrast and sizes. D-Saddle is tested on Fundus Image Registration (FIRE) Dataset that consists of 134 retinal image pairs. Experimental results show that D-Saddle successfully registered 43% of retinal image pairs with average registration accuracy of 2.329 pixels while a lower success rate is observed in other four state-of-the-art retinal image registration methods GDB-ICP (28%), Harris-PIIFD (4%), H-M (16%), and Saddle (16%). Furthermore, the registration accuracy of D-Saddle has the weakest correlation (Spearman) with the intensity uniformity metric among all methods. Finally, the paired t-test shows that D-Saddle significantly improved the overall registration accuracy of the original Saddle.
    Matched MeSH terms: Retina
  9. Fong KC, Ooi YL, Khang TF
    Eye (Lond), 2014 Sep;28(9):1148.
    PMID: 24875224 DOI: 10.1038/eye.2014.123
    Matched MeSH terms: Retina/drug effects*
  10. Aibinu AM, Iqbal MI, Shafie AA, Salami MJ, Nilsson M
    Comput Biol Med, 2010 Jan;40(1):81-9.
    PMID: 20022595 DOI: 10.1016/j.compbiomed.2009.11.004
    The use of vascular intersection aberration as one of the signs when monitoring and diagnosing diabetic retinopathy from retina fundus images (FIs) has been widely reported in the literature. In this paper, a new hybrid approach called the combined cross-point number (CCN) method able to detect the vascular bifurcation and intersection points in FIs is proposed. The CCN method makes use of two vascular intersection detection techniques, namely the modified cross-point number (MCN) method and the simple cross-point number (SCN) method. Our proposed approach was tested on images obtained from two different and publicly available fundus image databases. The results show a very high precision, accuracy, sensitivity and low false rate in detecting both bifurcation and crossover points compared with both the MCN and the SCN methods.
    Matched MeSH terms: Retina/pathology*
  11. 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
  12. 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*
  13. Wang L, Tan H, Yu J, ZhangBao J, Huang W, Chang X, et al.
    Eur J Neurol, 2023 Feb;30(2):443-452.
    PMID: 36286605 DOI: 10.1111/ene.15612
    BACKGROUND AND PURPOSE: The aim was to evaluate the potential of retinal nerve fiber layer thickness (RNFLT) measured with optical coherence tomography in predicting disease progression in relapsing-remitting multiple sclerosis (RRMS).

    METHODS: Analyses were conducted post hoc of this 24-month, phase III, double-blind study, in which RRMS patients were randomized (1:1:1) to once daily oral fingolimod 0.5 mg, 1.25 mg or placebo. The key outcomes were the association between baseline RNFLT and baseline clinical characteristics and clinical/imaging outcomes up to 24 months. Change of RNFLT with fingolimod versus placebo within 24 months and time to retinal nerve fiber layer (RNFL) thinning were evaluated.

    RESULTS: Altogether 885 patients were included. At baseline, lower RNFLT was correlated with higher Expanded Disability Status Scale score (r = -1.085, p = 0.018), lower brain volume (r = 0.025, p = 0.006) and deep gray matter volume (r = 0.731, p 

    Matched MeSH terms: Retina/pathology
  14. Sadikan MZ, Abdul Nasir NA, Lambuk L, Mohamud R, Reshidan NH, Low E, et al.
    BMC Ophthalmol, 2023 Oct 19;23(1):421.
    PMID: 37858128 DOI: 10.1186/s12886-023-03155-1
    Diabetic retinopathy (DR), one of the leading causes of visual impairment and blindness worldwide, is one of the major microvascular complications in diabetes mellitus (DM). Globally, DR prevalence among DM patients is 25%, and 6% have vision-threatening problems among them. With the higher incidence of DM globally, more DR cases are expected to be seen in the future. In order to comprehend the pathophysiological mechanism of DR in humans and discover potential novel substances for the treatment of DR, investigations are typically conducted using various experimental models. Among the experimental models, in vivo models have contributed significantly to understanding DR pathogenesis. There are several types of in vivo models for DR research, which include chemical-induced, surgical-induced, diet-induced, and genetic models. Similarly, for the in vitro models, there are several cell types that are utilised in DR research, such as retinal endothelial cells, Müller cells, and glial cells. With the advancement of DR research, it is essential to have a comprehensive update on the various experimental models utilised to mimic DR environment. This review provides the update on the in vitro, in vivo, and ex vivo models used in DR research, focusing on their features, advantages, and limitations.
    Matched MeSH terms: Retina/pathology
  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. 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*
  17. Maheshwari S, Kanhangad V, Pachori RB, Bhandary SV, Acharya UR
    Comput Biol Med, 2019 Feb;105:72-80.
    PMID: 30590290 DOI: 10.1016/j.compbiomed.2018.11.028
    BACKGROUND AND OBJECTIVE: Glaucoma is a ocular disorder which causes irreversible damage to the retinal nerve fibers. The diagnosis of glaucoma is important as it may help to slow down the progression. The available clinical methods and imaging techniques are manual and require skilled supervision. For the purpose of mass screening, an automated system is needed for glaucoma diagnosis which is fast, accurate, and helps in reducing the burden on experts.

    METHODS: In this work, we present a bit-plane slicing (BPS) and local binary pattern (LBP) based novel approach for glaucoma diagnosis. Firstly, our approach separates the red (R), green (G), and blue (B) channels from the input color fundus image and splits the channels into bit planes. Secondly, we extract LBP based statistical features from each of the bit planes of the individual channels. Thirdly, these features from the individual channels are fed separately to three different support vector machines (SVMs) for classification. Finally, the decisions from the individual SVMs are fused at the decision level to classify the input fundus image into normal or glaucoma class.

    RESULTS: Our experimental results suggest that the proposed approach is effective in discriminating normal and glaucoma cases with an accuracy of 99.30% using 10-fold cross validation.

    CONCLUSIONS: The developed system is ready to be tested on large and diverse databases and can assist the ophthalmologists in their daily screening to confirm their diagnosis, thereby increasing accuracy of diagnosis.

    Matched MeSH terms: Retina
  18. 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
  19. Tengku Kamalden, T.A., Nurliza, K., Haris, A.R.
    JUMMEC, 2008;11(1):30-32.
    MyJurnal
    The presenting signs of acute leukaemia occur as a result of bone marrow failure and organ infiltration. Increased bleeding tendencies are seen on the skin, gums and mucosal lining. Bleeding in the posterior segment of the eye, namely the retina and vitreous, may occur, but do not usually cause any visual disturbances. This case demonstrates visual loss as a result of premacular subhyaloid haemorrhage in acute leukaemia.
    Matched MeSH terms: Retina; Retinal Hemorrhage
  20. Jamal A, Hazim Alkawaz M, Rehman A, Saba T
    Microsc Res Tech, 2017 Jul;80(7):799-811.
    PMID: 28294460 DOI: 10.1002/jemt.22867
    With an increase in the advancement of digital imaging and computing power, computationally intelligent technologies are in high demand to be used in ophthalmology cure and treatment. In current research, Retina Image Analysis (RIA) is developed for optometrist at Eye Care Center in Management and Science University. This research aims to analyze the retina through vessel detection. The RIA assists in the analysis of the retinal images and specialists are served with various options like saving, processing and analyzing retinal images through its advanced interface layout. Additionally, RIA assists in the selection process of vessel segment; processing these vessels by calculating its diameter, standard deviation, length, and displaying detected vessel on the retina. The Agile Unified Process is adopted as the methodology in developing this research. To conclude, Retina Image Analysis might help the optometrist to get better understanding in analyzing the patient's retina. Finally, the Retina Image Analysis procedure is developed using MATLAB (R2011b). Promising results are attained that are comparable in the state of art.
    Matched MeSH terms: Retina
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