Ocular Structure Research Articles

Antimicrobial Resistance and Biofilm Formation by Staphylococcus aureus Isolated From Ocular Infections

Background: Untreated staphylococcal ocular infections may cause injuries in the ocular structure and lead to visual impairments, lesions in the anatomical ocular surface, and blindness. The aim of the study was to describe the characteristic of 90 Staphylococcus aureus (SA) strains from hospital and community treated ocular infections with a special emphasis on ability of biofilm formation and drug resistance. The biofilm formation was carried out using the Congo red agar (CRA) method applying Congo red dye. Studies have demonstrated that the CRA method is simple, fast, and repeatable and that modifications of some components can easily increase its accuracy. Methods: Biofilm formation was examined by the method with CRA test. On CRA, slime-producing strains formed black colonies, whereas nonproducing strains developed red colonies in 6 kinds of colors, from very red to very black: very red, red, burgundy, almost black, black, and very black. Antimicrobial susceptibility testing was performed by disc diffusion or the E-test method according to the current guidelines of the EUCAST. The MRSA, and MLSB phenotypes were detected. Polymerase chain reaction (PCR) was used to detect the mecA, and mupA genes. Erythromycin resistance genes (ermA, ermB, ermC, and msr) were detected by multiplex PCR. Results: A positive result of the CRA test was accomplished in 66.2% cases; significantly more often in hospital strains (73.4% vs 45.4%; OR, 3.3; 55% CI, 1.2–9.3). Moreover, 73.4% isolates were fully susceptible. In hospitalized patients, the level of resistance to at least 1 antimicrobial category has been identified as 40.9%, and this rate was 27.2% in outpatients. Among the tested strains, 5 (6.0%) had the resistance phenotype MRSA and 22 (26.5%) the resistance phenotype MLSB; 4 strains manifested both mechanisms; erythromycin resistance was 25.3% in those resistant to fluoroquinolones. Resistance to fluoroquinolones was 5 times more often found in ambulatory patients. All of the tested isolates were vancomycin sensitive. Conclusions: Biofilm formation is an important risk factor for developmental staphylococcal hospital-acquired ocular infections. Our results prove that hospital strains have demonstrated much greater biofilm-forming ability than nonhospital strains. Studies indicate the high efficacy of chloramphenicol and fluoroquinolones treatments, as well as the need to implement new solutions due to the aforementioned bacteria’s high resistance to neomycin and anatomic barriers difficulties.Disclosures: NoneFunding: None

Progress of ocular motor and structures in multiple sclerosis patients

Multiple sclerosis (MS) is a demyelinating disease of central nervous system, which often affects ocular region and causes structural and functional changes of eyes. Therefore, there have been plenty of researches on the alteration of motor and structures of eyes by MS. This paper reviews and summarizes the progress of MS-related changes of ocular motor, cornea, structure and blood flow of retina, and optic nerve, and may provide a new insight for related clinical researches. (Chin J Ophthalmol, 2020, 56: 711-715).

Pathophysiological Role and Drug Modulation of Calcium Transport in Ocular Surface Cells.

The ocular surface structure and extraocular accessory organs constitute the ocular surface system, which includes the cornea, conjunctiva, eyelids, lacrimal organs, and lacrimal passages. This system is composed of, and stabilized by, the corneal epithelium, conjunctival cells, conjunctival goblet cells, lacrimal acinar cells and Tenon's fibroblasts, all of which maintain the healthy eyeball surface system. Ocular surface diseases are commonly referred to corneal and conjunctival disease and external ocular disease, resulting from damage to the ocular surface structure. A growing body of evidence has indicated that abnormal activation of the KCa3.1 channel and Ca2+/ calmodulin-dependent kinase initiates ocular injury. Signaling pathways downstream of the irregular Ca2+ influx induce cell progression and migration, and impair tight junctions, epithelial transport and secretory function. In this overview, we summarize the current knowledge regarding ocular surface disease in terms of physical and pathological alteration of the ocular system. We dissect in-depth, the mechanisms underlying disease progression, and we describe the current calcium transport therapeutics and the obstacles that remain to be solved. Finally, we summarize how to integrate the research results into clinical practice in the future.

How to Safely Remove Live Nematode in The Eye

Objective: To provide information about a safe and easy technique to remove live nematode in the anterior chamber. Case Presentation: A 21-year old male presented with a sudden-onset of pain in right eye for 5 days. The complaint was accompanied with irritation and photophobia. On examination, visual acuity was 6/6,5 with his best corrected, with circumcorneal congestion. We performed slit-lamp examination on the AC and witnessed a thin, white motile object with wriggling movement, that was swimming live in AC. The worm was removed surgically from AC by using forceps and adding lidocain with nacl 0,9% intracorneal to stop its movement. The worm was sent to pathological anatomy department to be examined microscopically. Conclusion: A method of using lidocaine as a chemoparalysis substance has been proven effective to facilitate an easy removal of the worm so as to prevent major harm to the ocular structure.

Association of anthropometric measures across the life-course with refractive error and ocular biometry at age 15\u2009years

BackgroundA recent Genome-wide association meta-analysis (GWAS) of refractive error reported shared genetics with anthropometric traits such as height, BMI and obesity. To explore a potential relationship with refractive error and ocular structure we performed a life-course analysis including both maternal and child characteristics using data from the Avon Longitudinal Study of Parents and Children cohort.MethodsMeasures collected across the life-course were analysed to explore the association of height, weight, and BMI with refractive error and ocular biometric measures at age 15 years from 1613children. The outcome measures were the mean spherical equivalent (MSE) of refractive error (dioptres), axial length (AXL; mm), and radius of corneal curvature (RCC; mm). Potential confounding variables; maternal age at conception, maternal education level, parental socio-economic status, gestational age, breast-feeding, and gender were adjusted for within each multi-variable model.ResultsMaternal height was positively associated with teenage AXL (0.010 mm; 95% CI: 0.003, 0.017) and RCC (0.005 mm; 95% CI: 0.003, 0.007), increased maternal weight was positively associated with AXL (0.004 mm; 95% CI: 0.0001, 0.008). Birth length was associated with an increase in teenage AXL (0.067 mm; 95% CI: 0.032, 0.10) and flatter RCC (0.023 mm; 95% CI: 0.013, 0.034) and increasing birth weight was associated with flatter RCC (0.005 mm; 95% CI: 0.0003, 0.009). An increase in teenage height was associated with a lower MSE (− 0.007 D; 95% CI: − 0.013, − 0.001), an increase in AXL (0.021 mm; 95% CI: 0.015, 0.028) and flatter RCC (0.008 mm; 95% CI: 0.006, 0.010). Weight at 15 years was associated with an increase in AXL (0.005 mm; 95% CI: 0.001, 0.009).ConclusionsAt each life stage (pre-natal, birth, and teenage) height and weight, but not BMI, demonstrate an association with AXL and RCC measured at age 15 years. However, the negative association between refractive error and an increase in height was only present at the teenage life stage. Further research into the growth pattern of ocular structures and the development of refractive error over the life-course is required, particularly at the time of puberty.

Multifractal analysis of embryonic eye structures from female mice with dietary folic acid deficiency. Part I: Fractal dimension, lacunarity, divergence, and multifractal spectrum

Abstract The purpose of this study was to investigate effects of low maternal folic acid (FA) status on many eye structures in embryonic mice using multifractal analysis, a method for describing complex structural patterns. To do this, we used the FracLac plugin for ImageJ to analyse binary digital images of cornea, lens, retina, and vitreous after immunohistochemical analysis using anti-collagen IV or anti-laminin-1 antibodies. The box-counting and gliding box methods were used to generate metrics including the fractal dimension, lacunarity, divergence, and multifractal spectrum distance metrics for each ocular structure. Results were analysed using bootstrap resampling techniques and the Kruskal-Wallis significance test. For all structures and staining methods studied, differences between embryos from control vs FA-deficient females were detectable in lacunarity plots and multifractal spectra, and statistically significant in cornea, lens, retina and vitreous. Multifractal analysis detected even slight differences in tissue textures presumably attributable to altered expression of extracellular matrix molecules.

Coronavirus disease 2019 (SARS-CoV-2) and colonization of ocular tissues and secretions: a systematic review.

Coronavirus disease 19 (COVID-19) has been described to potentially be complicated by ocular involvement. However, scant information is available regarding severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) and ocular structures tropism. We conducted a systematic review of articles referenced in PubMed, Cochrane Library, Web of Science and Chinese Clinical Trial Register (ChiCTR) from December 20, 2019 to April 6, 2020, providing information on the presence of SARS-CoV-2 in cornea, conjunctiva, lacrimal sac, and tears. We excluded ongoing clinical studies as for unobtainable conclusive results. Of 2422 articles, 11 met the inclusion criteria for analysis and were included in the study. None of the studies were multinational. Among the 11 selected papers there were three original articles, one review, four letters, two editorials, and one correspondence letter. Globally, 252 SARS-CoV-2 infected patients were included in our review. The prevalence of ocular conjunctivitis complicating the course of COVID-19 was demonstrated to be as high as 32% in one study only. Globally, three patients had conjunctivitis with a positive tear-PCR, 8 patients had positive tear-PCR in the absence of conjunctivitis, and 14 had conjunctivitis with negative tear-PCR. The majority of the available data regarding SARS-CoV-2 colonization of ocular and periocular tissues and secretions have to be considered controversial. However, it cannot be excluded that SARS-CoV-2 could both infect the eye and the surrounding structures. SARS-CoV-2 may use ocular structure as an additional transmission route, as demonstrated by the COVID-19 patients’ conjunctival secretion and tears positivity to reverse transcriptase-PCR SARS-CoV-2-RNA assay.

An Assay System to Evaluate Riboflavin/UV-A Corneal Phototherapy Efficacy in a Porcine Corneal Organ Culture Model.

Simple summaryThe scope of this study is to quantitatively evaluate, with an automated digital image analysis method, the efficacy of riboflavin/UV-A corneal phototherapy on the cornea in a porcine corneal organ culture model of ulcerative melting keratitis. Riboflavin/UV-A corneal phototherapy provided a favorable outcome in the corneal wound healing process after chemical injury: the treatment restores the damaged corneas to the texture of healthy corneas. This automated image analysis method may be compared to clinical diagnostic methods, such as optical coherence tomography (OCT) imaging, for in vivo damaged ocular structural investigations. Positive results from this research could provide an opportunity for studying the effects of this method in other economically and emotionally valued species, such as dogs, cats, and horses. The relatively overall low treatment cost and the ease of performing the procedure make riboflavin/UV-A corneal phototherapy accessible to the veterinary market.The purpose of this study was to investigate the response of porcine corneal organ cultures to riboflavin/UV-A phototherapy in the injury healing of induced lesions. A porcine corneal organ culture model was established. Corneal alterations in the stroma were evaluated using an assay system, based on an automated image analysis method able to (i) localize the holes and gaps within the stroma and (ii) measure the brightness values in these patches. The analysis has been performed by dividing the corneal section in 24 regions of interest (ROIs) and integrating the data analysis with a “multi-aspect approach.” Three group of corneas were analyzed: healthy, injured, and injured-and-treated. Our study revealed a significant effect of the riboflavin/UV-A phototherapy in the injury healing of porcine corneas after induced lesions. The injured corneas had significant differences of brightness values in comparison to treated (p < 0.00) and healthy (p < 0.001) corneas, whereas the treated and healthy corneas showed no significant difference (p = 0.995). Riboflavin/UV-A phototherapy shows a significant effect in restoring the brightness values of damaged corneas to the values of healthy corneas, suggesting treatment restores the injury healing of corneas after lesions. Our assay system may be compared to clinical diagnostic methods, such as optical coherence tomography (OCT) imaging, for in vivo damaged ocular structure investigations.

Intracranial Effects of Microgravity: A Prospective Longitudinal MRI Study.

Background Astronauts on long-duration spaceflight missions may develop changes in ocular structure and function, which can persist for years after the return to normal gravity. Chronic exposure to elevated intracranial pressure during spaceflight is hypothesized to be a contributing factor, however, the etiologic causes remain unknown. Purpose To investigate the intracranial effects of microgravity by measuring combined changes in intracranial volumetric parameters, pituitary morphologic structure, and aqueductal cerebrospinal fluid (CSF) hydrodynamics relative to spaceflight and to establish a comprehensive model of recovery after return to Earth. Materials and Methods This prospective longitudinal MRI study enrolled astronauts with planned long-duration spaceflight. Measures were conducted before spaceflight followed by 1, 30, 90, 180, and 360 days after landing. Intracranial volumetry and aqueductal CSF hydrodynamics (CSF peak-to-peak velocity amplitude and aqueductal stroke volume) were quantified for each phase. Qualitative and quantitative changes in pre- to postflight (day 1) pituitary morphologic structure were determined. Statistical analysis included separate mixed-effects models per dependent variable with repeated observations over time. Results Eleven astronauts (mean age, 45 years ± 5 [standard deviation]; 10 men) showed increased mean volumes in the brain (28 mL; P < .001), white matter (26 mL; P < .001), mean lateral ventricles (2.2 mL; P < .001), and mean summated brain and CSF (33 mL; P < .001) at postflight day 1 with corresponding increases in mean aqueductal stroke volume (14.6 μL; P = .045) and mean CSF peak-to-peak velocity magnitude (2.2 cm/sec; P = .01). Summated mean brain and CSF volumes remained increased at 360 days after spaceflight (28 mL; P < .001). Qualitatively, six of 11 (55%) astronauts developed or showed exacerbated pituitary dome depression compared with baseline. Average midline pituitary height decreased from 5.9 to 5.3 mm (P < .001). Conclusion Long-duration spaceflight was associated with increased pituitary deformation, augmented aqueductal cerebrospinal fluid (CSF) hydrodynamics, and expansion of summated brain and CSF volumes. Summated brain and CSF volumetric expansion persisted up to 1 year into recovery, suggesting permanent alteration. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Lev in this issue.

Association of Long-Duration Spaceflight With Anterior and Posterior Ocular Structure Changes in Astronauts and Their Recovery

During long-duration spaceflights, nearly all astronauts exhibit some change in ocular structure within the spectrum of spaceflight-associated neuro-ocular syndrome. To quantitatively determine in a prospective study whether changes in ocular structures hypothesized to be associated with the development of spaceflight-associated neuro-ocular syndrome occur during 6-month missions on board the International Space Station (ISS). The Ocular Health ISS Study of astronauts is a longitudinal prospective cohort study that uses objective quantitative imaging modalities. The present cohort study investigated the ocular structure of 11 astronauts before, during, and after a 6-month mission on board the ISS. Changes in ocular structure (peripapillary edema, axial length, anterior chamber depth, and refraction) hypothesized to be associated with the development of spaceflight-associated neuro-ocular syndrome during 6-month missions on board the ISS were assessed. Statistical analyses were conducted from August 2018 to January 2019. Before launch, the 11 astronauts were a mean (SD) age of 45 (5) years, a mean (SD) height of 1.76 (0.05) m, and a mean (SD) weight of 75.3 (7.1) kg. Six astronauts did not have prior spaceflight experience, 3 had completed short-duration missions on board the Space Shuttle, and 2 had previous long-duration spaceflight missions on board the ISS. Their mean (SD) duration on board the ISS in the present study was 170 (19) days. Optic nerve head rim tissue and peripapillary choroidal thickness increased from preflight values during early spaceflight, with maximal change typically near the end of the mission (mean change in optic nerve head rim tissue thickness on flight day 150: 35.7 μm; 95% CI, 28.5-42.9 μm; P < .001; mean choroidal thickness change on flight day 150: 43 μm; 95% CI, 35-46 μm; P < .001). The mean postflight axial length of the eye decreased by 0.08 mm (95% CI, 0.10-0.07 mm; P < .001) compared with preflight measures, and this change persisted through the last examination (1 year after spaceflight: 0.05 mm; 95% CI, 0.07-0.03 mm; P < .001). This study found that spaceflight-associated peripapillary optic disc edema and choroid thickening were observed bilaterally and occurred in both sexes. In addition, this study documented substantial peripapillary choroid thickening during spaceflight, which has never been reported in a prospective study cohort population and which may be a contributing factor in spaceflight-associated neuro-ocular syndrome. Data collection on spaceflight missions longer than 6 months will help determine whether the duration of the mission is associated with exacerbating these observed changes in ocular structure or visual function.

Ocular Phenotype of Relaxin Gene Knockout (Rln-/-) Mice

ABSTRACT Purpose: To test if relaxin deficiency affects ocular structure and function we investigated expression of relaxin (Rln) and RXFP receptors (Rxfp1, Rxfp2), and compared ocular phenotypes in relaxin gene knockout (Rln−/− ) and wild type (Rln+/+ ) mice. Materials and Methods: Rln, Rxfp1 and Rxfp2 mRNA expression was detected in ocular tissues of Rln+/+ mice using RT-PCR. The eyes of 11 Rln−/− and 5 Rln+/+ male mice were investigated. Corneal and retinal thickness was assessed using optical coherence tomography. Intraocular pressure was measured using a rebound tonometer. Retinal, choroidal and sclera morphology and thickness were evaluated histologically. Eyes were collected and fixed for immunofluorescence staining or used for RNA extraction to evaluate mRNA expression using real-time PCR. Results: Rln mRNA was expressed only in the retina, whereas Rxfp1 transcripts were detected in the retina, cornea and sclera/choroid. Rxfp2 was only present in the cornea. None of these genes were expressed in the lacrimal gland, eyelid or lens. Intraocular pressure was higher and central cornea of Rln−/− mice was significantly thicker and had significantly larger endothelial cells and a lower endothelial cell density than Rln+/+ mice. Immunohistochemistry demonstrated no significant difference in AQP3 and AQP5 staining in the cornea or other regions between wildtype and Rln−/− mice. mRNA expression of Aqp4 was significantly higher in Rln−/− than in Rln+/+ corneas, whereas Col1a2, Mmp9, Timp1 and Timp2 were significantly decreased. Expression of Aqp1, Aqp4, Aqp5, Vim and Tjp1 was significantly decreased in Rln−/− compared to Rln+/+ uvea. No significant differences in these genes were detected in the retina. Retinal, choroidal and scleral thicknesses were not different and morphology appeared normal. Conclusion: The findings indicate that loss of Rln affects expression of several genes in the uvea and cornea and results in thicker corneas with altered endothelial cells. Many of the gene changes suggest alterations in extracellular matrix and fluid transport between cells.

Knowledge and attitude towards hazardous effects of laser pointers among attendees of football matches in Riyadh, Saudi Arabia

PurposeThere has been a recent increase in accidental retinal injuries due to the careless use of handheld laser devices. The scenarios under which these incidents occur suggest a lack of awareness of the sight-threatening hazards of some handheld lasers. This study aimed to assess knowledge of the population to plan awareness programs and establish protective health policies. MethodsThis observational cross-sectional study used a newly-developed, validated, and pilot-tested questionnaire to survey attendees of football matches in Saudi Arabia between September to October 2018. ResultsFive-hundred and sixty-nine attendees were surveyed, and 76% of respondents knew laser pointers were harmful and could damage the eye. However, 73% of respondents did not think that the blue laser was dangerous, indicating poor awareness regarding this particular laser. Only 38% knew which ocular structure is most commonly damaged, and 15.6% did not realize that brief exposure can cause vision loss. Females had better knowledge compared to males. Respondents between 25 and 40 years old, females, and married individuals had the highest levels of a positive attitude. There was no statistically significant difference in the mean knowledge score between those in the medical field and other fields (P = 0.5). ConclusionThere is an inadequate knowledge of protective measures against handheld lasers. However, there’s an overall positive attitude towards spreading awareness about this issue. Yet, targeted awareness campaigns are still needed in addition to more strict government laws to prevent importing or using high-powered handheld laser pointers.

Bullous Keratopathy in a dog treated with Third Eyelid Flap and Autologous Serum Eye Drops

Background: Bullous Keratopathy (BK) is characterized by decompensation of the corneal stroma resulting in visual impairment by corneal opacity, discomfort, excessive tearing, blepharospasm and pain. The aim of this study was to report a case of BK in a dog and the complete recovery of the ocular structure and visual function, with a third eyelid flap associated with the use of autologous blood serum topically.Case: A 2-year-old Shih Tzu male dog, weighing 4.3 kg, with recurrent bilateral eye discomfort was brought to Ophthalmologist Veterinarian Assistance. The patient had already been seen by other veterinarians, but the signs returned in a short period of time after the prescription was suspended. During physical examination it was observed moderate blepharospasm in the right eye, epiphora in the left eye, and in both eyes was noted exophthalmos, medial corneal entropion, caruncle trichiasis and ectopic cilia in the upper and lower eyelids. Fluorescein test was positive in both eyes, and a large bullous, opaque and gelatinous lesion with irregular appearance was observed occupying a large part of the cornea of the right eye. Superficial corneal ulcer was diagnosed in left eye and BK in right eye, both probably in consequence of ectopic cilia presence. Surgical intervention was made, with the cauterization and excision of the ectopic cilia and third eyelid flap in the right eye. The cauterization of caruncle trichiasis was not authorized by the owner. Moxifloxacin eye drops in the dose of one drop four times a day in both eyes, lubricant based on hyaluronic acid in the dose of one drop four times a day in both eyes, and autogenous blood serum, obtained from the centrifugation of a blood sample of the dog itself, in the dose of one drop every hour in the right eye for 24 hours, and meloxicam in the dose of 0.1 mg/kg every 24 h for 3 days were prescribed. Elizabethan collar was recommended until removal of the third eye flap. During the surgery, a sample of eye secretion was collected and sent for culture and antibiogram and did not show growth of microorganisms. After seven days of the procedure, the animal did not show eye discomfort and corneal ulcer in the left eye was healed. The third eye flap remained stable until the return of 28 days and after removal of the capton, adhesions were identified, which were removed with Castroviejo scissors after application of topical anesthetic proxymetacaine hydrochloride eye drops. A fluorescein test was performed and the absence of corneal keratitis was confirmed. Discrete corneal scars (macula) were identified.Discussion: The patient in this report had several changes in ocular morphology that favored the formation of recurrent injuries which contributed to the formation of BK. The use of topical medications as unique treatment was not performed due to the severity of the lesion and the presence of alterations such as medial entropion, caruncle trichiasis and ectopic cilia that needed surgical corrections to resolve the causes of the lesions. In order to protect the cornea and provide compression of its epithelium, a third eyelid flap was performed, a low-invasive procedure that is quick and easy to perform. Ectopic cilia were cauterized to eliminate one of the causes of the corneal injuries, however, the other changes could not be corrected because they were not authorized by the owner. The adjuvant uses of ocular lubricant based on hyaluronic acid, a broad-spectrum topical antibiotic and mainly autogenous blood serum favored the epithelial reconstruction of the cornea by providing protection, vitamins, growth factors, immunoglobulins, anti-collagenolytic and bacteriostatic substances. The protocol used it enabled a rapid reduction in patient discomfort, reversal of injuries and recovery of visual function.

Knowledge and attitude towards hazardous effects of laser pointers among attendees of football matches in Riyadh, Saudi Arabia.

PURPOSE:There has been a recent increase in accidental retinal injuries due to the careless use of handheld laser devices. The scenarios under which these incidents occur suggest a lack of awareness of the sight-threatening hazards of some handheld lasers. This study aimed to assess knowledge of the population to plan awareness programs and establish protective health policies.METHODS:This observational cross-sectional study used a newly-developed, validated, and pilot-tested questionnaire to survey attendees of football matches in Saudi Arabia between September to October 2018.RESULTS:Five-hundred and sixty-nine attendees were surveyed, and 76% of respondents knew laser pointers were harmful and could damage the eye. However, 73% of respondents did not think that the blue laser was dangerous, indicating poor awareness regarding this particular laser. Only 38% knew which ocular structure is most commonly damaged, and 15.6% did not realize that brief exposure can cause vision loss. Females had better knowledge compared to males. Respondents between 25 and 40 years old, females, and married individuals had the highest levels of a positive attitude. There was no statistically significant difference in the mean knowledge score between those in the medical field and other fields (P = 0.5).CONCLUSION:There is an inadequate knowledge of protective measures against handheld lasers. However, there's an overall positive attitude towards spreading awareness about this issue. Yet, targeted awareness campaigns are still needed in addition to more strict government laws to prevent importing or using high-powered handheld laser pointers.

Immediate Effect of Yoga Exercises for Eyes on the Macular Thickness.

Background:Yoga exercises for eyes have been advocated as beneficial to eye health. In a previous study, we evaluated the effect of yoga exercises for eyes on the intraocular pressure (IOP). The other aspects of the effects of yoga exercises for eyes to ocular structure have not been investigated yet.Aim:The aim of this study is to evaluate the effect of yoga exercises for eyes on the macular structure using the optical coherence tomography (OCT) and OCT angiography (OCTA) parameters.Methods:Twenty-nine participants were included in this masked within participant comparison of healthy controls. Basic ophthalmic examination was performed, after which patients were evaluated for IOP, OCT, and OCTA before and after yoga exercises for eyes. OCT/A parameters that were evaluated were: average macular thickness (AMT) (μm), central macular thickness (μm), central choroidal thickness (μm) vessel density (%) in the superficial, deep vascular layers, and in the choriocapillaris.Results:IOP was significantly reduced (postexercise IOP = 13.02 mmHg ± 2.82 mmHg) from the initial value (preexercise IOP = 13.86 mmHg ± 2.85 mmHg, P = 0.02). AMT significantly increased (postexercise AMT = 275.40 μm ± 10.85 μm) from the preexercise measurement (preexercise AMT = 274.41 μm ± 10.89 μm; P = 0.02).Conclusion:After yoga ocular exercises, IOP significantly decreased and AMT significantly increased in healthy controls, suggesting an effect of these exercises on the macular thickness.

An update on effects of ionizing radiation exposure on the eye

AbstractOver the past half century, the International Commission on Radiological Protection (ICRP) has considered that the lens is the most radiosensitive ocular structure, and has recommended dose limits for the lens to prevent occurrence of vision impairing cataracts (VICs). Epidemiological evidence that doses much lower than previously thought produce cataracts led ICRP to recommend reducing dose threshold for VICs and reducing the equivalent dose limit for the lens in 2011, when only a single threshold of 0.5 Gy was recommended. Based on epidemiological evidence, no dose rate effect was assumed and it was assumed that minor opacities progress into VICs. This contrasts with previously recommended separate thresholds each for different exposure scenarios, and for minor opacities and VICs. The absence of dose rate effect was based on the observed similar thresholds for protracted exposures in Chernobyl cleanup workers and in the Japanese atomic bomb survivors. Progression was assumed predicated on similar risks of cataracts and cataract surgery. Since 2012, there has been mounting epidemiological evidence for cataracts, also for other ocular diseases (e.g., glaucoma, diabetic neuropathy and macular degeneration). This presentation deals with the scientific basis of the ICRP 2011 recommendation, discusses the plausibility of two assumptions considering emerging scientific evidence, and considers radiosensitivity of the lens among ocular structures.

Certain Anterior and Posterior Ocular Structure Measurements Acquired by Swept-Source Optical Coherence Tomography in Patients with Inflammatory Bowel Disease

Certain Anterior and Posterior Ocular Structure Measurements Acquired by Swept-Source Optical Coherence Tomography in Patients with Inflammatory Bowel Disease

Recent progress of high-altitude environment impact on the eyes

High-altitude environment has its unique characteristics, which can cause a variety of acute and chronic mountain sicknesses.With increasing human activities at high altitude, the impact of high altitude exposure on human body has become a hotspot.Hypobaric hypoxia, strong breeze, strong radiation and excess ultraviolet exposure can induce pathophysiological changes in human body and eyes.Individual difference exists in response to high-altitude environment.In order to provide ideas for further study on the mechanisms of ocular changes at high altitude, this article reviewed the characteristics of high-altitude environment and their impact on the eyes, including visual function (vision, color vision, visual field and visual electrophysiology), intraocular pressure, ocular structures (tear film, conjunctiva, cornea, pupil, lens and fundus) and ocular treatments. Key words: High-altitude environment; Visual function; Intraocular pressure; Ocular structure; Ocular treatment

Liposomes for effective drug delivery to the ocular posterior chamber

BackgroundAge-related macular degeneration (AMD) is a leading cause of severe visual deficits and blindness. Meanwhile, there is convincing evidence implicating oxidative stress, inflammation, and neovascularization in the onset and progression of AMD. Several studies have identified berberine hydrochloride and chrysophanol as potential treatments for ocular diseases based on their antioxidative, antiangiogenic, and anti-inflammatory effects. Unfortunately, their poor stability and bioavailability have limited their application. In order to overcome these disadvantages, we prepared a compound liposome system that can entrap these drugs simultaneously using the third polyamidoamine dendrimer (PAMAM G3.0) as a carrier.ResultsPAMAM G3.0-coated compound liposomes exhibited appreciable cellular permeability in human corneal epithelial cells and enhanced bio-adhesion on rabbit corneal epithelium. Moreover, coated liposomes greatly improved BBH bioavailability. Further, coated liposomes exhibited obviously protective effects in human retinal pigment epithelial cells and rat retinas after photooxidative retinal injury. Finally, administration of P-CBLs showed no sign of side effects on ocular surface structure in rabbits model.ConclusionsThe PAMAM G3.0-liposome system thus displayed a potential use for treating various ocular diseases.

Research progress on clinical factors of pediatric ocular trauma

Ocular trauma is the leading cause of blindness among pediatric monocular non-congenital eye diseases, which can greatly disturb the development of visual function and ocular histological structure, thus adding economic and psychological burdens to the children and their families. The evaluation, clinical characteristics, classification, as well as causes of the trauma are analyzed in this article, and the clinical factors and research progress of pediatric ocular trauma are summarized, which might provide references for the prevention of it. Key words: Trauma, ocular; Pediatrics; Factors, clinical; Progress, research