Future clinical applicability of optical coherence tomography angiography. Chua J et al. Clin Exp Optom. 2018.
Optical coherence tomography angiography (OCT-A) is an emerging technology that enables non-invasive imaging of ocular microvascularisation. Despite numerous studies supporting the potential clinical use of this technique, OCT-A is still rarely used in clinical routine. This study analyses the technical and clinical aspects of OCT-A imaging and considers its future clinical potential. https://onlinelibrary.wiley.com/doi/abs/10.1111/cxo.12854
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Vitreous Wiping, a new technique for removal of vitreous cortex remnants during vitrectomy. Koen A. van Overdam et al. ACTA Ophthalmologica, 2018.
Vitreoschisis is an abnormal posterior detachment of the vitreous (spontaneous or iatrogenic). Due to its lamellar structure, the outermost layer of the vitreous cortex can remain attached to the retina and exert traction on it. Remnants of vitreous cortex (RCV) from vitreoschisis and not removed are associated with macular pathology, and if they are present on the retinal periphery they may play a role in proliferative vitreoretinopathy and post-vitrectomy retinal detachment. Existing instruments for the removal of these debris carry a substantial risk of iatrogenic retinal damage. This study evaluates the use of a new technique, called Vitreous Wiping, for the removal of RCV during vitrectomy.
https://onlinelibrary.wiley.com/doi/full/10.1111/aos.13991
3.Genome-wide association analyses identify 139 loci associated with macular thickness in the UK Biobank cohort. Gao XR et al. Hum Mol Genet, 2018.
The macula of the eye is responsible for fundamental functions such as central and high-resolution vision. Structural changes in the macula are associated with many eye diseases, including age-related macular degeneration (AMD) and glaucoma. Although macular thickness is a highly heritable trait, genome-wide association studies (GWAS) do not yet exist. This work represents the first GWAS study on macular thickness analysed in 68,423 participants by means of optical coherence tomography. The study identified genome-wide 139 loci significantly associated with macular thickness. The cross-phenotypic analysis of these genetic loci also showed that they have pleiotropic effects on myopia, neurodegenerative diseases (e.g. Parkinson's disease, schizophrenia and Alzheimer's disease), cancer (e.g. breast, ovarian and lung) and metabolic traits (e.g. body mass index, waist circumference and type 2 diabetes).
4.Association Between Noninfectious Uveitis and Psychological Stress. Berlinberg EJ et al. JAMA Ophthalmol, 2018.
Uveitis involves dysregulation of the ocular immune system. Stress has been shown to affect immune function, but it is unclear whether there is an association between stress and uveitis. This study evaluated the possible association between uveitis and psychological stress in 146 adult individuals with non-infectious uveitis, comparing them with a control group with no ocular disease. The results suggest that patients with uveitis have higher levels of psychological stress than controls, but no significant difference was identified in the stress of patients with active vs. controlled uveitis.
https://jamanetwork.com/journals/jamaophthalmology/fullarticle/10.1001/jamaophthalmol.2018.5893
Tear Inflammatory Cytokines Analysis and Clinical Correlations in Diabetes and Non-diabetes with Dry Eye. Liu R et al. Am J Ophthalmol, 2018.
The study aims to improve knowledge of dry eye (DE) in diabetic disease by assessing ocular surface area and tear inflammatory cytokine levels. To this end, the researchers analysed 32 diabetic patients with ED, 24 diabetics without ED, 28 non-diabetics with ED and 29 healthy volunteers as a control group. The study shows that epidermal growth factor (EGF) levels in tears were significantly increased in patients with diabetes and DE. The researchers suggest that, in patients with diabetes, the amount of tear EGF could represent a diagnostic biomarker of ED.
https://linkinghub.elsevier.com/retrieve/pii/S0002-9394(18)30669-X
6.Alterations in gut bacterial and fungal microbiomes are associated with bacterial Keratitis, an inflammatory disease of the human eye. Jayasudha R et al. J Biosci, 2018.
Dysbiosis of the gut microbiome has been linked to numerous diseases and more recently also to eye diseases. This study investigates the association between dysbiosis and bacterial keratitis. Bacterial and fungal gut microbiomes were analysed using faecal samples from healthy controls (HC, n = 21) and patients with bacterial keratitis (BK, n = 19). The study revealed that numerous bacteria and fungi with anti-inflammatory and probiotic properties are enriched in healthy subjects and depleted in BK patients. Proinflammatory and pathogenic bacterial and fungal populations are, on the other hand, enriched in the microbiome of BK patients. This represents the first study to demonstrate a dysbiosis of bacterial and fungal communities in the gut of BK patients compared to healthy subjects.
https://www.ias.ac.in/article/fulltext/jbsc/043/05/0835-0856
7.The effect of pregnancy on tear osmolarity. Duran M et al. Cont Lens Anterior Eye, 2018.
The aim of the study was to examine the effect of pregnancy on the tear system by measuring tear osmolarity and the Schirmer test. For this purpose, the researchers analysed women in the first trimester of pregnancy and compared them with a group of non-pregnant women. The measurement of tear osmolarity and the Schirmer 1 tear function test showed a statistical difference between the first- and last-trimester results of the study group and between the latter and the control group. The study revealed that both tear osmolarity and Schirmer test values decreased significantly towards the end of pregnancy.
https://www.ncbi.nlm.nih.gov/pubmed/30482511
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8.Clinical signs of meibomian gland dysfunction (MGD) are associated with changes in meibum sphingolipid composition. Paranjpe V et al. Ocul Surf, 2018.
Sphingolipids (SPLs) play a role in cell communication, inflammation and apoptosis.
Changes in SPL composition have been reported in subjects with meibomian gland dysfunction (MGD), but associations between clinical signs of MGD and changes in SPL composition have never been analysed. To this end, the authors of this study analysed the relative composition of SPL in the sebaceous secretion (meibum) of 43 patients with MGD. The relative analysis of SPL composition revealed that individuals with poor-quality meibum had a lower amount of ceramide, hexosyl-ceramide and sphingosine 1-phosphate and a higher amount of sphingomyelin and sphingosine than individuals with good-quality meibum. The study thus reveals that the quality of the sebaceous secretion, associated with compositional changes in sphingolipids, could be considered a marker of MGD.
https://www.ncbi.nlm.nih.gov/pubmed/30553001
9.An action video game for the treatment of amblyopia in children: A feasibility study. Gambacorta C et al. Vision Res, 2018.
The gold standard in the treatment of childhood amblyopia is patching the eye with the highest visual acuity. However, adherence to patching and other treatment options is often poor. Fast-paced action video games, on the other hand, can be very addictive and have demonstrated improvements in adult amblyopia. This study tested an action video game specifically for the treatment of children with amblyopia. Twenty-one children with unilateral amblyopia completed 20 hours of monocular play; participants were assessed for visual acuity (VA), stereo acuity and reading speed at baseline, after 10 and 20 hours of play. After 20 hours of training, VA and stereo acuity improved and were maintained at follow-up. The study suggests, therefore, that the video game approach can be used as an additional treatment for amblyopia in children, achieving results similar to those of gold standard treatment, but in a shorter time.
https://www.sciencedirect.com/science/article/pii/S0042698918300580?via%3Dihub
10.?9-Tetrahydrocannabinol and Cannabidiol Differentially Regulate Intraocular Pressure. Sally Miller et al. Investigative Opthalmology & Visual Science, 2018.
It has long been known that cannabis and its psychoactive constituent ?9-tetrahydrocannabinol (THC) reduce intraocular pressure (IOP). THC probably acts through one of the known cannabinoid-related receptors (CB1, CB2, GPR18, GPR119, GPR55), but this correlation has never been proven. Cannabidiol (CBD), another main constituent of cannabis, has been considered by other studies to have no effect on IOP. This study analysed the effects of THC and CBD, applied locally on mice, on IOP. The study showed that THC reduces IOP by activating CB1 and GPR18 receptors in a sex-dependent manner. CBD, contrary to expectations, showed in the study two opposite effects on IOP and the ability to interfere with the effects of THC.
https://iovs.arvojournals.org/article.aspx?articleid=2718702
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New study reveals contrasting effects of cannabis on intraocular pressure
Dr. Carmelo Chines
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