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    ABSTRACT: Abstract Purpose: To investigate whether the g.4760C > T mutation in the catalase gene (CAT) is a risk factor for primary open angle glaucoma (POAG) in the Saudi population. Methods: A cohort of 225 unrelated POAG patients and 403 unrelated control subjects from Saudi Arabia were genotyped for a single nucleotide polymorphism (SNP; rs1001179; g.4760C > T) in the CAT gene utilizing Taq-Man® assay. The association between mutant genotypes and various clinical indices important for POAG was also investigated. Results: The distribution of different genotypes was comparable between both study groups. The genotype "C/C" was predominant among cases; 169 (75.1%) as well as among the controls; 289 (71.7%). As for the heterozygous mutated genotype "C/T", it was present in 52 (23.1%) of cases and 103 (25.6%) of controls, where the homozygous fully mutated genotype was present in only 4 (1.8%) of cases and 11 (2.7%) of the controls. The distribution of mutant allele was similar in both study groups (p = 0.218). Interestingly, there was a trend of association between the type of the mutation (homozygous versus heterozygous) and three clinical parameters important for predicting the severity of the disease. These parameters include mean age of onset, mean level of intraocular pressure (IOP) and mean months of duration of encountering glaucoma. Conclusions: There were no statistically significant differences between cases and controls in terms of the different genotype distribution. This mutation is possibly associated with various clinical indices important for POAG and thus may be used as a parameter for assessing POAG severity, at least in this population.
    Ophthalmic Genetics 12/2013; 34(4):223-8. DOI:10.3109/13816810.2013.789534
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    ABSTRACT: Retinal degeneration such as age-related macular degeneration and other inherited forms, such as Stargardt's disease and retinitis pigmentosa, and optic neuropathies including glaucoma and ischemic optic neuropathy are major causes of vision loss and blindness worldwide. Damage to retinal pigment epithelial cells and photoreceptors in the former, and to retinal ganglion cell axons in the optic nerve and their cell bodies in the retina in the latter diseases lead to the eventual death of these retinal cells, and in humans there is no endogenous replacement or repair. Cell replacement therapies provide 1 avenue to restore function in these diseases, particularly in the case of retinal repair, although there are considerable issues to overcome, including the differentiation and integration of the transplanted cells. What stem cell sources could be used for such therapies? One promising source is induced pluripotent stem cells (iPSCs), which could be drawn from an individual patient needing therapy, or generated and banked from select donors. We review developing research in the use of iPSCs for retinal cell replacement therapy.
    11/2013; DOI:10.1016/j.trsl.2013.11.002
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    ABSTRACT: Abstract Purpose: To evaluate the effect of punctal plug use in preventing dry eye after laser in situ keratomileusis (LASIK). Materials and Methods: A randomized clinical trial at a tertiary eye care center, Riyadh, Saudi Arabia. Participants underwent LASIK for myopia in both eyes and a lower punctal occlusion in one eye only while the other eye served as control. Both eyes received the same postoperative medications except for lubricant duration (subject eye: four times per day for one week; control eye: four times per day for 6 months). Participants were evaluated at 1 week, 2, and 6 months after surgery for signs and symptoms of dry eye. The main outcome measures were visual acuity; ocular surface parameters; and Ocular Surface Disease Index questionnaire. Results: Seventy-eight eyes of 39 patients were included in this study. The Ocular Surface Disease Index scores of eyes with punctal plugs were better at all follow-up visits, and the differences between both eyes were statistically significant (1 week, p < 0.0001; 2 months, p < 0.0001; 6 months, p = 0.008). At the final follow-up visit, the percentage of normal eyes was higher in eyes with punctal plugs for all ocular surface parameters (Schirmer 1 test, 94.9%; tear breakup time, 77.8%; punctate epithelial keratitis score, 71.8%) compared to eyes without occlusion (Schirmer 1 test, 92.3%; tear breakup time, 58.3%; punctate epithelial keratitis score, 53.8%); however, such differences were not statistically significant. Conclusion: Punctal plug insertion after LASIK surgeries may minimize the need for frequent lubricant application and hence improve patient satisfaction.
    Current eye research 10/2013; DOI:10.3109/02713683.2013.841258
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    ABSTRACT: To evaluate outcomes of temporary silicone oil (SO) tamponade in patients with complex retinal detachment. A retrospective study of 184 eyes of 177 consecutive patients who underwent SO removal (SOR) by one surgeon between 2000 and 2010. Indications for the use of SO were proliferative vitreoretinopathy (56 eyes), difficult rhegmatogenous retinal detachment (RRD) (58 eyes), diabetic traction retinal detachment (DTRD) (29 eyes), RRD due to macular hole in highly myopic eyes (16 eyes), giant retinal tears (13 eyes), and RRD after penetrating trauma (12 eyes). All eyes underwent prophylactic 360° laser retinopexy and encircling buckle at the time of primary surgery. The mean duration of SO tamponade was 47 weeks, with a mean follow-up of 66.9 weeks after SOR. Anatomical success after SOR was achieved in 96.73 %. Final visual outcome of ≥20/200 was significantly higher in eyes with RRD compared to eyes with DTRD. Young age (≤16 years), performance of pars plana lensectomy at primary procedure and presence of pseudophakia at last follow-up were factors associated with good visual outcome in eyes with RRD. Factors predicting attached retina at last follow-up were older age (>16 years), normal intraocular pressure (IOP) at initial presentation and no relaxing retinotomy performed during the primary procedure in eyes with RRD. Complications were cataract (100 %) in phakic eyes, increased IOP (15.7 %), keratopathy (3.8 %), and hypotony (2.1 %). The low redetachment rate after SOR in the present study might be due to prophylactic 360° retinopexy and use of encircling buckles at time of primary retinal reattachment.
    International Ophthalmology 10/2013; DOI:10.1007/s10792-013-9857-9
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    ABSTRACT: Molecular diagnosis of human disorders is referred to as the detection of the various pathogenic mutations in DNA and/or RNA samples in order to facilitate detection, diagnosis, sub-classification, prognosis, and monitoring response to therapy. The use of molecular biology techniques to expand scientific knowledge of the natural history of diseases, identify people who are at risk for acquiring specific diseases, and diagnose human diseases at the nucleic acid level. Molecular diagnostics combines laboratory medicine with the knowledge and technology of molecular genetics and has been enormously revolutionized over the last decades, benefiting from the discoveries in the field of molecular biology. This review will discuss in details the recent advances in molecular diagnostics and how the Arabian Peninsula can benefit from those techniques knowing for a fact the high percentages of consanguineous marriages and the tribal nature of marriages which resulted in high incidence of genetic diseases.
    Saudi medical journal 10/2013; 34(10):995-1001.
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    ABSTRACT: Abstract We investigated whether the c.47T > C polymorphism (SNP rs4880) in the manganese superoxide dismutase (SOD2) gene is a risk factor for primary angle closure glaucoma (PACG) in the Saudi population. Among cases (n = 139), the prevalence of various genotypes were 25.9%, 46.8% and 27.3% for T/T, C/T and C/C genotypes respectively. This trend was similar in the controls (n = 403); 22.6%, 50.1% and 27.3% for T/T, C/T and C/C respectively. The differences in genotype distribution were not statistically significant (p = 0.391 and 0.682 respectively). The minor allele frequency was 50.7% in cases and 52.4% in controls; this difference was not statistically significant (p = 0.676). Investigating the potential association between this SOD2 polymorphism and different clinical indices, there was a statistically significant difference among different genotype groups in terms of three important clinical indices for PACG; Mean age at onset, duration of onset to and the mean LogMAR visual acuity (p = 0.041, 0.018 and 0.033 respectively). The three markers are highly associated prognostic factors to diseases severity. If our results are proven in larger cohort and in various populations, then this SNP may have potentiality to be used as an indicator for PACG severity.
    Ophthalmic Genetics 09/2013; DOI:10.3109/13816810.2013.838276
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    ABSTRACT: Abstract Background: To evaluate possible monogenic and chromosomal anomalies in a patient with unilateral Duane retraction syndrome and modest dysmorphism. Materials and Methods: Clinical evaluation, sequencing of candidate genes, and array comparative genomic hybridization (array CGH). Results: The proband had unilateral Duane retraction syndrome (DRS) with low-set ears bilaterally, a high arched palate, and clinodactyly. Motor development and cognitive function were normal. Parents were first cousins, but no other family member was similarly affected. No mutations were detected in the HOXA1. KIF21A. SALL4, TUBB3, and CHN1 genes. Array CGH revealed a 16 Kb de novo deletion at chromosome 8p11.2 that encompassed a portion of only one gene, the Cholinergic Receptor, Nicotinic, Beta-3 (CHRNB3, Neuronal). This gene encodes a protein that is involved in the nicotinic acetylcholine receptor on neurons. It interacts functionally with other genes that code components of the acetylcholine receptor. Conclusions: This patient's chromosomal abnormality affected only one gene that is highly expressed in the brainstem and brain, involved in neurotransmission, and could be related to her Duane retraction syndrome.
    Ophthalmic Genetics 09/2013; DOI:10.3109/13816810.2013.835431
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    ABSTRACT: Abstract Background: To evaluate possible monogenic and chromosomal anomalies in a patient with unilateral Duane retraction syndrome, modest dysmorphism, cerebral white matter abnormalities, and normal cognitive function. Materials and Methods: Performing high-resolution array comparative genomic hybridization (array CGH) and sequencing of HOXA1, KIF21A, SALL4, and CHN1 genes. Results: The proband had unilateral Duane retraction syndrome (DRS) type III on the right with low-set ears, prominent forehead, clinodactyly, and a history of frequent infections during early childhood. Motor development and cognitive function were normal. Parents were not related, and no other family member was similarly affected. MRI revealed multiple small areas of high signal on T2 weighted images in cerebral white matter oriented along white matter tracts. Sequencing of HOXA1, KIF21A, SALL4, and CHN1 did not reveal any mutation(s). Array CGH showed a 95 Kb de novo duplication on chromosome 19q13.4 encompassing four killer cell immunoglobulin-like receptor (KIR) genes. Conclusions. KIR genes have not previously been linked to a developmental syndrome, although they are known to be expressed in the human brain and brainstem and to be associated with certain infections and autoimmune diseases, including some affecting the nervous system. DRS and brain neuroimaging abnormalities may imply a central and peripheral oligodendrocyte abnormality related in some fashion to an immunomodulatory disturbance.
    Ophthalmic Genetics 08/2013; 36(1). DOI:10.3109/13816810.2013.827218
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    ABSTRACT: The aim was to obtain an overview of general medical practitioner (GP) referral pathways to ocular health care and allied services for people identified with age-related macular degeneration (AMD), diabetic retinopathy (DR) or glaucoma (GL). A questionnaire was developed to survey GPs in Australia. Questions included demographic information and referral patterns to ocular and health service providers. The survey was posted to 1,050 randomly selected GPs across Australia. Fifty-eight GPs participated in this study amounting to a 6.5 per cent response rate. Nearly all GPs referred patients to ophthalmologists (AMD: 98 per cent; DR: 98 per cent; GL: 95 per cent). A smaller proportion of GPs also referred to low vision rehabilitation (LVR) services (AMD: 34 per cent; DR: 33 per cent; GL: 22 per cent), optometrists (AMD: 26 per cent; DR: 34 per cent; GL: 31 per cent), or support services (AMD: 17 per cent; DR: 40 per cent; GL: 19 per cent). For the three tested conditions, there were no statistically significant differences in the proportions of GPs, who referred to ophthalmologists (p = 0.43), optometrists (p = 0.48) or to low vision rehabilitation services (p = 0.31). The proportion of GPs who referred to support services was significantly higher for patients diagnosed with DR than AMD or GL (p < 0.05). The majority of GPs referred patients with AMD, DR or GL to ophthalmologists. Fewer GPs considered referrals to optometrists, low vision rehabilitation or support services. General practitioners may need to be more aware about the central role of optometrists in the delivery of primary eye health care. In the interest of optimising eye care, closer working relationships between GPs and optometrists should be fostered.
    Clinical and Experimental Optometry 08/2013; 97(2). DOI:10.1111/cxo.12102
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    ABSTRACT: To conduct a systematic review on the safety of ranibizumab injections for diabetic macular edema by meta-analysis of recently conducted level 1 randomized clinical trials. A meta-analysis and systematic review. Main outcome measures of permissible studies were extracted and reported. The relative risk (RR) for thromboembolic events (TEEs) was calculated for those studies that met this study's inclusion criteria. The fixed-effects model (Mantel-Haenszel method) was appropriately used to calculate the pooled RR. The quality of trials was assessed using the Jadad score. Of the 2072 patients who were included from 4 eligible randomized clinical trials, 1295 patients received intravitreal ranibizumab injections. The pooled RR for TEEs after ranibizumab intravitreal injection was 0.74 (95% CI 0.52-1.06). Intravitreal ranibizumab for the treatment of diabetic macular edema did not increase the risk for TEEs as shown by this meta-analysis of 4 randomized, controlled clinical trials.
    Canadian Journal of Ophthalmology 08/2013; 48(4):317-23. DOI:10.1016/j.jcjo.2013.03.004
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