MyMedR

Fulltext Zone specific fractal dimension of retinal images as predictor of stroke incidence

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*

Fulltext Differential expression and role of hyperglycemia induced oxidative stress in epigenetic regulation of β1, β2 and β3-adrenergic receptors in retinal endothelial cells

Safi SZ, Qvist R, Yan GO, Ismail IS

BMC Med Genomics, 2014;7:29.

PMID: 24885710 DOI: 10.1186/1755-8794-7-29

Aberrant epigenetic profiles are concomitant with a spectrum of developmental defects and diseases. Role of methylation is an increasingly accepted factor in the pathophysiology of diabetes and its associated complications. This study aims to examine the correlation between oxidative stress and methylation of β1, β2 and β3-adrenergic receptors and to analyze the differential variability in the expression of these genes under hyperglycemic conditions.

Matched MeSH terms: Retina/pathology*

Retinal vascular fractal and blood pressure in a multiethnic population

Sng CC, Wong WL, Cheung CY, Lee J, Tai ES, Wong TY

J Hypertens, 2013 Oct;31(10):2036-42.

PMID: 23787404 DOI: 10.1097/HJH.0b013e328362c201

OBJECTIVE(S): To examine the effect of blood pressure (BP) on retinal vascular fractal dimension (Df), a measure of microvascular network complexity and density in a multiethnic cohort.
METHODS: A population-based study of 3876 Chinese, Malay and Indian participants in Singapore. Retinal Df was measured using a computer-based program from digital retinal photographs. Associations between retinal Df and mean arterial BP (MABP) in the whole cohort and in each racial group were analysed using linear regression analysis. Logistic regression was used to examine the association between retinal Df and hypertension status.
RESULTS: The mean retinal Df of the study population was 1.45 (standard deviation 0.03). After adjustment for age, sex, race, diabetes, BMI, cholesterol and creatinine levels, persons with smaller Df had higher MABP (mean difference MABP was 6.18 mmHg comparing lowest to highest Df quartiles, P<0.001). This was similar in Chinese, Malay and Indian persons [mean difference 6.40 (P<0.001), 4.72 (P=0.011) and 6.62 (P<0.001)mmHg, respectively]. Persons with smaller retinal Df were more likely to have uncontrolled treated or untreated hypertension [odds ratio 1.79 (P=0.003) and 2.60 (P=0.003), respectively, comparing lowest to highest Df quartiles] than those with no hypertension; this relationship was not seen comparing persons with controlled treated hypertension with no hypertension (odds ratio 1.01, P=0.972).
CONCLUSION: Hypertension was associated with a sparser retinal vascular network, which was similar across different racial/ethnic groups and most apparent in those with uncontrolled or untreated hypertension. These data suggest that microvascular remodelling can be quantified by measuring retinal vasculature.

Matched MeSH terms: Retina/pathology

Fulltext The structural effect of intravitreal Brilliant blue G and Indocyanine green in rats eyes

Ooi YL, Khang TF, Naidu M, Fong KC

Eye (Lond), 2013 Mar;27(3):425-31.

PMID: 23196646 DOI: 10.1038/eye.2012.260

To compare the potential retinal toxicity of two commercially Brilliant blue G dyes (Brilliant Peel and Ocublue Plus) and Indocyanine green (ICG) at usual clinical concentration.

Matched MeSH terms: Retina/pathology

Fulltext Branch retinal vein occlusion associated with quetiapine fumarate

Yong KC, Kah TA, Ghee YT, Siang LC, Bastion ML

BMC Ophthalmol, 2011;11:24.

PMID: 21867521 DOI: 10.1186/1471-2415-11-24

To report a case of branch retinal vein occlusion in a young adult with bipolar mood disorder treated with quetiapine fumarate.

Matched MeSH terms: Retina/pathology*

Mass mortality of hatchery-produced larvae of Asian seabass, Lates calcarifer (Bloch), associated with viral nervous necrosis in Sabah, Malaysia

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

Vascular intersection detection in retina fundus images using a new hybrid approach

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*

Fulltext Images in clinical medicine. Retinal detachment in malignant hypertension

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*

Retinopathy in acute leukaemia at initial diagnosis: correlation of fundus lesions and haematological parameters

Reddy SC, Jackson N

Acta Ophthalmol Scand, 2004 Feb;82(1):81-5.

PMID: 14738490

PURPOSE: To determine the prevalence of retinal changes in newly diagnosed acute leukaemia patients, and to establish the relationship between retinal lesions and haematological parameters in these patients.

METHODS: A total of 127 patients with acute leukaemia (myeloid and lymphoid), of both genders, aged between 13 and 77 years, were examined by an ophthalmologist for retinal changes using direct/indirect ophthalmoscopy within 2 days of diagnosis before starting chemotherapy.

RESULTS: Retinal lesions were seen in 62 cases (49%), with intraretinal haemorrhages being the most common lesion (42%). A high white blood cell count was significantly associated with intraretinal haemorrhages (p = 0.04) and white-centred haemorrhages (p = 0.001), while a low platelet count was significantly associated with intraretinal haemorrhages (p = 0.03) in acute myeloid leukaemia patients.

CONCLUSIONS: A high white blood cell count may be considered as important as a low platelet count in the pathogenesis of leukaemic retinopathy.

Matched MeSH terms: Retina/pathology*

Late clinical and magnetic resonance imaging follow up of Nipah virus infection

Lim CC, Lee WL, Leo YS, Lee KE, Chan KP, Ling AE, et al.

J Neurol Neurosurg Psychiatry, 2003 Jan;74(1):131-3.

PMID: 12486285

The Nipah virus is a newly identified paramyxovirus responsible for an outbreak of fatal encephalitis in Malaysia and Singapore. This paper reports the follow up clinical and magnetic resonance imaging findings in 22 affected subjects. Of 13 patients with encephalitis, one died, one was lost to follow up, and seven recovered. Among the four remaining patients, one had residual sixth nerve palsy, another suffered from severe clinical depression, and a third patient had evidence of retinal artery occlusion. One patient with delayed onset Horner syndrome had a single lesion in the cervical spinal cord. The brain magnetic resonance findings were stable or improved in nine patients over 18 months of follow up. Among a second group of nine asymptomatic seropositive abattoir workers, magnetic resonance examination in seven subjects revealed discrete small lesions in the brain; similar to those detected in encephalitis patients. These findings suggest that in addition to encephalitis, the newly discovered Nipah virus affects the spinal cord and the retina. Late clinical and radiological findings can occur in Nipah virus infections as with other paramyxoviruses.

Matched MeSH terms: Retina/pathology

Fundus magnification produced during direct ophthalmoscopy of the corrected eye

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*

Retinal findings in adult leukaemia: correlation with leukocytosis

Jackson N, Reddy SC, Hishamuddin M, Low HC

Clin Lab Haematol, 1996 Jun;18(2):105-9.

PMID: 8866143

The associations between retinal findings and haematological parameters in acute leukaemia are controversial. Sixty-three newly-diagnosed acute leukaemia patients, aged 12-77 years, were studied prospectively for the presence of intra-retinal haemorrhages (IRH), white-centred haemorrhages (WCH), cotton wool spots (CWS) and macular haemorrhages (MH), Thirty-three patients (52.4%) showed at least one retinal abnormality. The prevalence of individual findings was: IRH (30 cases), WCH (20 cases), CWS (5 cases), MH (11 cases). In contrast to previous studies, there was no association between any of these retinal findings and the haemoglobin level or the platelet count. There was a higher median WBC in patients with IRH (68 x 10(9)/l) than in those without IRH (15.4 x 10(9)/l), P = 0.037. When the acute myeloblastic leukaemia cases were considered separately, an association was also found between higher WBC and the presence of WCH and CWS. There was no association between retinal findings and FAB type in the AML cases. We conclude that a high WBC may be at least as important as anaemia and thrombocytopenia in the pathogenesis of the retinopathy of acute leukaemia.

Matched MeSH terms: Retina/pathology*

Bilateral Norrie's disease in identical twins

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/pathology

Advanced retinoblastoma in Malaysian children

Sinniah D, Narasimha G, Prathap K

Acta Ophthalmol, 1980 Oct;58(5):819-24.

PMID: 7211270

Twenty children with retinoblastoma are reviewed who were treated at the University Hospital, Kuala Lumpur over a 10-year-period. They constitute 6.6% of childhood malignancies and without exception all presented with advanced disease. Hereditary cases were notably absent in the the series probably because past cases have almost invariably succumbed without an opportunity to transmit the gene. With enucleation and radiotherapy six of the patients have survived from 2 to 12 years. The addition of vincristine and cyclophosphamide has not been associated with improved survival.

Matched MeSH terms: Retina/pathology

Displaying publications 21 - 34 of 34 in total