1.3D bioprinting of a corneal stroma equivalent. Isaacson A et al. Experimental Eye Research. August 2018, 173:188-193.
Corneal transplantation is one of the main treatments for severe cases of loss of corneal function. The production of functional, synthetic corneal prostheses is an interesting challenge for scientists worldwide. As such, 3D bioprinting is an emerging technology that can be used to produce biological tissues for clinical applications. The study shows the use of 3D bioprinting to construct corneal tissue to produce corneal structures similar to the human corneal stroma. The researchers used an existing 3D digital human corneal model and a suitable support structure. 3D bio-printing was performed with a collagen-based bio-ink containing encapsulated corneal keratocytes. The keratocytes showed high cell viability both at day 1 after printing (> 90%) and at day 7 (83%).
https://www.ncbi.nlm.nih.gov/pubmed/29772228
2. Genome-wide association meta-analysis highlights light-induced signalling as a driver for refractive error. Milly S. Tedja et al. Nature Genetics, 2018; 50 (6): 834.
Refractive errors are the most frequent eye disorders globally. This genome-wide association meta-analysis, performed on 160,420 participants and replicated on 95,505, led to an increase in the number of independent signals identified for refractive errors from 37 to 161 and found a high genetic correlation between Europeans and Asians (> 0.78). The authors identified retinal cell physiology and light processing as prominent mechanisms. The study also identifies functional contributions to the development of refractive error in all cell types of the neurosensory retina, retinal pigment epithelium, vascular endothelium and extracellular matrix. The identified genes implicate novel mechanisms, suggesting the idea that refractive errors are caused by a light-dependent cascade of retinal events.
https://www.nature.com/articles/s41588-018-0127-
3. Clinical Manifestations and Pathogenesis of Uveitis in Ebola Virus Disease Survivors. Yeh S et al. Ocul Immunol Inflamm. 2018 Jul 11:1-7.
Following the Ebola virus outbreak (EVD) that developed between 2014 and 2016, thousands of EVD survivors are at risk of ophthalmic manifestations, at high risk of visual impairment, ranging from anterior uveitis to panuveitis. Clinical studies conducted on infection survivors, animal models and translational investigations have provided insight into the pathogenesis of ocular pathology. In particular, the ocular inflammation observed in infection survivors is believed to involve direct viral infection, inflammation and tissue oedema. This article summarises the current knowledge on the clinical manifestations and pathogenesis of uveitis in Ebola survivors. Key points for future research to unravel the mechanisms underlying the broad clinical spectrum of infection are also discussed.
https://www.ncbi.nlm.nih.gov/pubmed/29993303
Biomarkers and predictors for functional and anatomic outcomes for small gauge pars plana vitrectomy and peeling of the internal limiting membrane in naïve diabetic macular oedema: The VITAL Study. Iglicki M et al. PLoS One. 2018 Jul 11;13(7).
The multicentre study, conducted on 120 patients, investigates biomarkers and predictive factors for long-term visual and anatomical outcome in patients with diabetic macular oedema (EMD) undergoing first-line treatment with vitrectomy via pars plana (PPV).
The results reveal a significant functional and anatomical improvement 24 months after primary PPV, without the need for further EMD therapy (such as intravitreal treatment or macular laser) within the follow-up period. According to the authors, early surgery and the presence of subretinal fluid (SRF) are good predictors of a positive visual outcome.
https://www.ncbi.nlm.nih.gov/pubmed/29995929
Recent advances of nanoparticle-based topical drug delivery to the posterior segment of the eye. Wang Y et al. Expert Opin Drug Deliv. Jul 9, 2018.
The number of patients suffering from diseases of the posterior segment of the eye is increasing, there is a strong demand for effective release drugs in the posterior segment.
The development of a nanoparticle-based drug delivery system offers an option to overcome the limitations of conventional drug delivery systems by improving the permeability of the drug across barriers and allowing the desired level of drug to reach the target tissue. This paper summarises novel drug delivery systems (including lipid nanoparticles, liposomes, emulsions) and analyses the possibility of using 'nanocarriers', which are currently under clinical studyt for posterior segment diseases.
https://www.ncbi.nlm.nih.gov/pubmed/29985660
6. Change in eyelid parameters after orbital decompression in thyroid-associated orbitopathy. Hong Hyun Park et al. Eye 2018 (32): 1036-104.
This study was conducted on 202 eyes of 109 patients with thyroid orbitopathy in order to investigate quantitative changes in eyelid parameters after orbital decompression surgery. The authors used digital photographs of the patients taken immediately before and after orbital decompression surgery and the degree of exophthalmos was measured by means of Hertel exophthalmometry. The eyelid parameters, analysed with the use of customised software, included: pupil distance from the lower eyebrow (PBD), margin-reflex distance 1 (MRD1), margin-reflex distance 2 (MRD2), eyelid fissure (PF), total eyelid length, upper and lower eyelid length, area, medial area, central area and lateral area. The study showed that there was a reduction of the lateral lower eyelid area (lateral area + length of the lower eyelid) after the decompression surgery. https://www.nature.com/articles/s41433-018-0022-6
7.Association Between the Cilioretinal Artery and Choroidal Neovascularization in Age-Related Macular Degeneration. Kiersten Snyder, MS et al. JAMA Ophthalmol. July 2018.
The study aims to investigate the role of the retinal vasculature in the pathogenesis of choroidal neovascularisation (CNV) in advanced age-related macular degeneration (AMD). To determine whether the presence and location of a cilio-retinal artery may be associated with the risk of advanced AMD, the authors associated eyes with a cilio-retinal artery with a lower prevalence of CNV, a lower severity score of AMDLE, and a lower 5-year incidence of CNV.
The authors conclude that the presence of a cilio-retinal artery correlates with a lower risk of developing CNV, but not central geographic atrophy (CGA), suggesting a possible retinal haemodynamic contribution to the pathogenesis of neovascular AMD.
https://jamanetwork.com/journals/jamaophthalmology/fullarticle/2686391
8. Development and Evaluation of Diagnostic Criteria for Vogt-Koyanagi-Harada Disease. Yang P, Zhong Y, Du L, et al, JAMA Ophthalmol. 2018 Jul 5.
Vogt-Koyanagi-Harada syndrome (VKH) is a disease of presumed autoimmune aetiology, characterised by chronic, bilateral, diffuse granulomatous uveitis with dermatological, neurological and auditory involvement. To date, there are no well-defined diagnostic criteria (DCV) for this disease, and in order to determine them, the authors of this study examined the medical records of 634 patients with VKH and 623 with non-VKH-related uveitis from southern China. In addition, to validate the diagnostic criteria, the authors evaluated a further group of 537 patients with definite VKH and one of 525 patients with non-VKH-related uveitis from northern China. The DCVs developed and evaluated in the study showed high sensitivity, however, being based on a retrospective analysis, should be validated through further prospective studies on other populations.
https://jamanetwork.com/journals/jamaophthalmology/article-abstract/2686393
9.Dietary flavonoids and the prevalence and 15-y incidence of age-related macular degeneration. Bamini Gopinath et al. American Journal of Clinical Nutrition, 2018.
This exploratory study evaluated the association between flavonoid intake and the 15-year prevalence and incidence of age-related macular degeneration (AMD). The study was conducted in a population of 2,856 adults over 49 years of age, of whom 2,037 were monitored up to 15 years later and included in prevalence and incidence analyses, respectively. The authors concluded that participants who consumed more oranges than those who had never eaten any showed a reduced risk of AMD over 15 years, suggesting an independent, protective association between dietary flavonoid intake and the likelihood of AMD.
10. Scleral hypoxia is a target for myopia control. Hao Wu et al. PNAS July 2018.
Myopia is among the main causes of visual impairment. Myopic eyes are characterised by remodelling of the extracellular matrix (ECM), the underlying mechanisms of which are unknown. The study found that the factor 1? (HIF-1?) hypoxia-inducible signal promotes myopia through trans-differentiation of myofibroblasts. Anti-hypoxic treatments did, in fact, prevent the molecular changes associated with HIF-1?, suppressing myopia progression.
http://www.pnas.org/content/early/2018/07/06/1721443115.long
To read a short review of the article written by the editors of l'OI, click here https://www.oculistaitaliano.it/articoli/ipossia-sclerale-come-possibile-target-per-il-controllo-della-miopia/
Dr. Carmelo Chines
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