Eye Corneal Research Articles

Thirty years of eye bank experience at a single centre in India.

The global survey of eye banking and corneal transplantation reveals differences in eye banking trajectories in various countries. There is a need to encourage and lay down foundations of successful eye banking practices in many nations across the world map. The study evaluates demographics, trends in donor cornea retrieval, utilization and eye banking practices in over 30years at a single eye bank in India. A longitudinal descriptive analysis of eye banking practices from 1989 to 2018 at Ramayamma International Eye Bank, Hyderabad, India, was performed. Data on eye donations, practice patterns and various types of keratoplasty were collected. Data were analysed focusing on practices and historical development of the eye bank. Over the years, the eye bank has made use of several advances in its practice patterns and evolved to a stage of self-sustainability. With the fulfilment of internal demand for corneal transplantation, 50% of retrieved corneas could be distributed for community needs outside the institute. Number of transplants increased from 20 in 1987 to 4738 in 2018. Total number of transplants touched 27,746 in 2018 which might be the highest numbers for a single centre anywhere in the world. The study reveals a dynamic development of the eye bank over the last 30years and emphasizes the importance of an active quality management in coping with the challenges of modern eye banking. The increasing trend of cornea collection and transplantation is a reflection of the needs and efforts towards treating and eliminating corneal blindness.

Association of KIF26B and COL4A4 gene polymorphisms with the risk of keratoconus in a sample of Iranian population.

Keratoconus (KTCN) is a congenital corneal eye disorder which correlates with abnormal distribution of the collagen fiber and causes loss of visual acuity. COLA4A gene has a substantive role in collagen synthesis, whereas KIF26B as a new candidate gene belonging to kinesin superfamily (KIFs) has been suggested to be associated with this disease. So, in this preliminary study, we simultaneously evaluated the effects of two single nucleotide polymorphisms, 222855rs7C/T and rs12407427C/T, on KTCN susceptibility in a sample of Iranian population. The present case-control study consists of 144 patients confirmed with KTCN and 153 healthy controls. The variants are genotyped by using amplification refractory mutation system-polymerase chain reaction method. The findings disclosed that rs2228557C/T and rs12407427C/T polymorphisms significantly increased the risk of KTCN in measured (codominant1; p = 0.0001, codominant2; p = 0.0001, codominant3; p = 0.0006, dominant; p = 0.0001, over-dominant; p = 0.0005) and (codominant1; p = 0.0001, codominant3; p = 0.0005, recessive; p = 0.0001) inheritance patterns, respectively. Our results did prove a statistical association of both rs2228557 and rs12407427 genotypes (TT and CT + CC) and allele (T) with KTCN susceptibility in Iranian population. Further studies in other ethnicities are required to verify our results.

Prospective insulin-based ophthalmic delivery systems for the treatment of dry eye syndrome and corneal injuries

The presence of insulin (INS) receptors on the ocular surface (OS) and lacrimal gland (LG), and the high prevalence of dry eye syndrome (DES) and corneal lesions in diabetic patients suggest that INS is relevant for OS homeostasis and wound healing. The study aims at developing delivery systems for the topical administration of INS to the OS in order to improve INS local bioavailability and evaluate the influence of the delivery systems on DES in diabetic rats (DM) (n = 05/group). Chitosan microparticles (MP), chitosan/poloxamer gel (GEL) and MP-loaded GEL (GELMP), with or without INS were developed. Formulations were instilled into the eyes of diabetic rats (DM) for 15 days and the tear fluid volume, corneal cells morphology and cornea thickness were assessed and compared with an aqueous dispersion of INS (DISP-INS). All delivery systems had pH of about 6, osmolality suitable for topical application and positive zeta potential. The MPs with or without INS had sizes close to 4 μm, spherical morphology and INS encapsulation efficiency of 77 ± 6%. DISP-INS and GELMP-INS formulations produced tear secretion amounts significantly higher than those receiving formulations containing no INS and similar to healthy animals. Cornea surface impression cytology showed that treatment with INS-delivery systems and not DISP-INS almost normalized cells morphology. Treatment with GELMP-INS increased INS by 2.5 in the LG and eyeball as compared to the groups treated with GEL-INS and MP-INS, while treatment with DISP-INS left no traces of drug in the eye after treatment termination. GEL and GELMP containing INS were also able to normalize the thickness of the corneal epithelia. In conclusion, GELMP-INS normalized tear fluid volume, corneal thickness, protected corneal cells morphology and increased ocular bioavailability of INS, making it a promising treatment strategy for DES and corneal lesions.

Clinical study of the radiotherapy with EDGE accelerator in the treatment of the moderate and severe thyroid associated ophthalmopathy.

To explore the short-term efficacy, acute complications and response factors after the radiotherapy with EDGE accelerator in patients with moderate and severe thyroid-associated ophthalmopathy (TAO). A total of 68 patients with moderate and severe TAO who received the radiotherapy with EDGE accelerator between August 1st, 2017 and May 1st, 2011 were enrolled in the present study. The clinical data were collected, and the efficacy and acute complications were followed up, and the response factors were analyzed. Sixty-eight patients (136 eyes) were followed up for 6 months after radiotherapy. The total score after radiotherapy was significantly lower compared to that before the therapy (p<0.05), and the effective rate was 75.74%. After the radiotherapy, the patient's exophthalmia, soft tissue involvement, eye external muscle involvement, corneal involvement, decreased vision and diplopia, tearing and eyelid pain have improved. Acute complications included increased local inflammation, hair loss, pigmentation and xerophthalmias. In addition, multivariate logistic regression analysis demonstrated that thyroid hormone level was the independent factor for the response to the radiotherapy. For patients with moderate and severe TAO, radiotherapy with EDGE accelerator is a safe and effective treatment option. Maintaining normal thyroid hormone level can improve the effective rate of radiotherapy.

Comparison of atracurium and vecuronium as muscle relaxants for ocular and orthopaedic interventions in dogs

Twenty adult dogs of either sex, divided into 2 equal groups were used for evaluation of atracurium (0.5 mg/kg IV) and vecuronium (0.1 mg/kg IV) in atropine-butorphanol-diazepam premedicated and propofol (till effect IV) induced dogs which were further maintained on isoflurane with controlled IPPV mode of the ventilator for positive pressure ventilation. A total of 13 ophthalmic and 7 orthopaedic interventions were done in both the groups. Pulmonary parameters were measured at baseline (pre-operative), just after induction and at 5, 15, 30 and 45 minutes after the administration of NMBA and the recovery parameters were recorded after weaning from the anaesthetic gas. The eyeballs deviated to the ventro-medial position after the induction with diazepam and propofol and resumed the central position within 30 seconds of atracurium or vecuronium administration thus, proving highly beneficial for the eye globe and corneal interventions. On a comparative basis, atracurium and vecuronium provided muscle relaxation for 40.1 ± 4.71 and 37.7 ± 1.01 minutes respectively. Uniform and pronounced muscle relaxation along with excellent sedation was found in both the groups. All pulmonary parameters remained within normal range. Following discontinuation of the isoflurane, the time taken to bear weight was 38.88 ± 1.45 and 39.63 ± 4.08 minutes in the atracurium and vecuronium groups respectively.

Efficacy of Omega-3 Fatty Acid Supplementation for Treatment of Dry Eye Disease: A Meta-Analysis of Randomized Clinical Trials.

To assess whether omega-3 fatty acid (FA) supplementation is more efficacious than placebo in amelioration of signs and symptoms of dry eye disease. We performed a systematic literature search in PubMed, Scopus, Web of Science, and Cochrane Central Register of Controlled Trials databases. We included randomized clinical trials comparing omega-3 FA supplementation with placebo in patients with dry eye disease. The outcome measures were dry eye symptoms, breakup time (BUT), Schirmer test, and corneal fluorescein staining. The pooled effect sizes were estimated using a random-effects model. Heterogeneity was evaluated using the Q and I tests. Sensitivity analysis and assessment of publication bias were performed. Meta-regression was performed to evaluate the source of heterogeneity. Seventeen randomized clinical trials involving 3363 patients were included. Compared with placebo, omega-3 FA supplementation decreased dry eye symptoms [standardized difference in mean values (SDM) = 0.968; 95% confidence interval (CI) 0.554-1.383; P < 0.001] and corneal fluorescein staining (SDM = 0.517; 95% CI, 0.043-0.991; P = 0.032), whereas it increased the BUT (SDM = 0.905; 95% CI, 0.564-1.246; P < 0.001) and Schirmer test values (SDM = 0.905; 95% CI, 0.564-1.246; P < 0.001). No evidence of publication bias was observed, and sensitivity analyses indicated the robustness of results obtained. Meta-regression analysis showed a higher improvement of dry eye symptoms and BUT in studies conducted in India. This meta-analysis provides evidence that omega-3 FA supplementation significantly improves dry eye symptoms and signs in patients with dry eye disease. Therefore, our findings indicate that omega-3 FA supplementation may be an effective treatment for dry eye disease.

Isolated Corneal Chemical Eye Injury Following Splash From Plantain Stem Sap: A Case Report and Review of Literature

Purpose: This article reports a case of corneal injury following a splash from the sap of plantain stem. Case Report: A 54-year-old female presented with a history of plantain stem sap splash into her right eye of 7-h duration with associated ocular pain, tearing, photophobia, and blurring of vision. On ocular examination, visual acuity was 6/18 OD; slit lamp examination revealed a well-delineated fluorescein-positive corneal epithelial defect with associated mild stromal edema. Left eye examination was essentially normal. She washed her face and eyes with water immediately after the splash and further had eye irrigation by attending ophthalmologist on presentation. The patient was immediately commenced on prednisolone, moxifloxacin, cyclopentolate, and ascorbate eye drops and tetracycline ointment. Corneal edema resolved in 4 days whereas the epithelial defect was completely healed by day 12 and visual acuity was restored to 6/6. Conclusion: Although farmers are exposed daily to various types of eye injuries from parts of plants, this report highlights corneal eye injury following plantain stem sap splash in a farmer who did not use protective eye goggles while working in the farm and how prompt institution of treatment can sight loss and loss of corneal integrity.

Effects of flap diameter on dry eye parameters and corneal sensation after femtosecond laser-assisted LASIK.

PURPOSE:Although femtosecond laser-assisted LASIK (laser-assisted in situ keratomileusis). provides a controllable flap size than a mechanical microkeratome, patients still experience dry eye symptoms after LASIK. The purpose of this study is to investigate the effects of different flap sizes on postoperative dry eye syndrome and corneal sensitivity.PATIENTS AND METHODS:This is a retrospective comparative study. Fifty-seven consecutive patients (113 eyes) who underwent myopic femtosecond laser-assisted LASIK treatment were recruited. Basic Schirmer's test value, tear breakup time (TBUT), corneal fluorescein staining scores, conjunctival rose bengal staining scores, and corneal sensitivity were measured before surgery, at postoperative 1, 3, and 6 months follow-up.RESULTS:When the eyes were grouped by flap diameter sizes (8.7 mm as the cutoff value), there were no significant differences in terms of corneal sensitivity and all dry eye parameters investigated at any time points between the large or small flap diameter groups. However, when the eyes were grouped by the ratio of flap diameter/horizontal corneal white-to-white distance (0.756 as the cutoff value), the larger ratio group showed decreased basic Schirmer's test (7.52 ± 4.43 mm) than the smaller group (12.15 ± 8.14) at 3 months (P = 0.006). Moreover, the group that had larger flap/corneal diameter ratio showed shorter TBUT (4.20 ± 1.73 s) than the smaller group (5.67 ± 1.90 s) at 6 months postoperatively (P = 0.011).CONCLUSIONS:LASIK-related dry eye syndrome was associated with flap/corneal diameter ratio, and surgeons should keep this effect in mind when customizing the cornea flap sizes for dry eye patients during LASIK.

Awareness, knowledge, and attitudes regarding eye donation and corneal transplantation among medical and paramedical students

Background: Eyes are sensitive, and highly specialized sense organs which are exposed to several disorders, many of which lead to impaired vision. The aim of this study was to assess the level of awareness and determine the level of willingness to donate eyes among the medical and paramedical students in Saudi Arabia. Methodology: A cross-sectional study was conducted on 350 paramedical and medical students from all six levels of study. The sampling method was convenience sampling. Data collection was done through online questionnaires which included demographic data, knowledge of eye donation, and willingness to donate. Results: The analysis on awareness of eye transplant among paramedical and medical students revealed that students who were aware of eye transplant were 35%, p=0.065, 95% CI [25.5%, 35.45]. The proportion of those who were aware that Saudi Arabia has an eye bank was less than 7%, p=.000, 95% CI [.4%,3.3%]. Willingness to donate eye(s) and awareness of eye donation were independent &amp;#967;(1)=.213, p=.644. Conclusion: The study findings indicate that organ donation and particularly eye donation is still low in Saudi Arabia.There is an acute need to increase awareness among the public.

Determination of Central Corneal Thickness in Patients with Refractive Anomalies and Emmetropy

Aim: The purpose of this study was to compare measurements of CCT in emmetropia and patient with refractive anomalies. Methods: We represent a retrospective research which was conducted at the University Clinical Center of Kosovo (UCCK). In this study were included 80 patients, divided into two groups: test and a control group. Mean age was (M = 25.90, DS = 7.16), men (N = 41% or 51.3%) and women (N = 39% or 48%). Results: Results show that there were no differences in the CCT, Hyperopic (M = 545.21 DS = 52.24), Myopic (M = 547.90 DS = 47.93) and Emmetropic (M = 550.75 DS = 41.29). After measuring of the longitudinal axis and analyzing the data by means of Anova test, it appeared to be a significant difference between the analyzed groups, Hyperopic (M = 21.99, DS = 1.27), Myopics (M = 23.21, DS = 1.24), Emmetropic (M = 22.36, DS = 0.81). Results also revealed that there is correlation between the CCT and IOP, where increase CCT decreases IOP and vice versa (r = -0.26, p = 0.01). Conclusion: The results have shown that CCT is thinner in myopic but does not show correlation with hypermetropic and emmetropic. While during the measurement of central corneal thickness and eye tension it is found that there is a negative correlation between them. Keratometry has a negative correlation with CCT. While there was no correlation between CCT and age. Given the role of CCT in interpreting IOP values, it is recommended to perform a systematic CCT measurement in routine clinical practice, which would assist in the diagnosis of ocular hypertension.

Role of scleral tectonic graft in saving the vision of a child with apert syndrome

Apert syndrome (AP) is a rare form of acrocehpalosyndactyly with autosomal-dominant transmission. The most common ocular features of patients with AP include proptosis, shallow orbits, and hypertelorism; they can have exotropia and antimongoloid slant of the palpebral fissures. The aim of this report was to study the role of scleral tectonic patch graft (STPG) in managing the corneal exposure due to AP. This was the clinical case report of a 9-year-old girl with AP, presented with right eye corneal perforation. She was treated with homologous STPG instead of tectonic corneal graft with good improvement of her visual acuity (VA). The outcome of the patient VA after 1 year was the improvement of the vision in the affected eye from the hand movement to 6/12, which was considered very satisfactory to the child and her family. This case report revealed that tectonic scleral patch graft is a sight-saving procedure in condition where the scleral tissue is readily available rather than the corneal tissue that needs the presence of cornel banks.

Biochemical Characterization of Bacterial Pathogens from Corneal Eye Infections and their Control via Chemotherapy, Phytotherapy and Apitherapy

Biochemical Characterization of Bacterial Pathogens from Corneal Eye Infections and their Control via Chemotherapy, Phytotherapy and Apitherapy

The Role of SKQ1 (Visomitin) in Inflammation and Wound Healing of the Ocular Surface.

IntroductionSkQ1 (Visomitin) is a novel mitochondrial-targeted antioxidant that holds promise in the treatment of inflammation associated with ocular surface diseases such as dry eye disease (DED) and corneal wounds. However, the specific role of SkQ1 in ocular surface epithelial tissue has yet to be explicated. The goal of this study is to identify roles of SkQ1 in conjunctival inflammation and corneal wound healing.MethodsTo determine the role of SkQ1 in inflammation, human conjunctival epithelial (HCjE) cell cultures were sensitized with pro-inflammatory cytokine tumor necrosis factor alpha (TNF-α) and interleukin 1 beta (IL-1β) followed by treatments with SkQ1. The production of inflammatory biomarker prostaglandin E2 (PGE2) and cell viability were quantitatively evaluated. To determine the role of SkQ1 in wound healing, human corneal limbus epithelial (HCLE) cell cultures were streaked to create wounds. The wound closure times, ability to support single HCLE cell proliferation and changes of cell migration in the presence of SB203580, an inhibitor of p38 mitogen-activated protein kinase (MAPK), were further compared.ResultsThe HCjE and HCLE cultures showed no apparent cytotoxicity to SkQ1 in concentrations up to 250 nM (HCjE) or 2500 nM (HCLE). The HCLE cultures showed no toxicity to SkQ1 at all the SkQ1 concentrations tested. SkQ1 significantly suppressed PGE2 production of HCjE at concentrations < 300 nM (24 h) and 50 nM (48 h), apparently being SkQ1 dose and treatment time dependent. The wound closure rates were increased by 4% in 4 h and by 9% after 8–12 h in the presence of 50 nM SkQ1. Furthermore, as little as 25 nM of SkQ1 significantly stimulated HCLE single-cell proliferation. Lastly, the SkQ1-stimulated wound healing was completely abolished by SB203580.ConclusionResults of the current study demonstrate that SkQ1 exhibits an anti-inflammatory role and can be safely applied to ocular surface epithelium up to a concentration of 300 nM (181 ng/ml) for 24 h. SkQ1 also significantly enhances corneal epithelial wound healing, likely through enhancement of cell proliferation and migration. The data provide solid support for SkQ1 as a promising new therapeutic strategy for treatment of conjunctival inflammation as well as corneal wounds.FundingThis study was sponsored by Mitotech SA Pharmaceuticals.Electronic supplementary materialThe online version of this article (10.1007/s40123-018-0158-2) contains supplementary material, which is available to authorized users.

First report of autochthonous canine leishmaniasis caused by Leishmania (L.) mexicana in Sinaloa, Mexico

Leishmaniasis is a neglected tropical disease caused by different species of protozoan parasites of the genus Leishmania. Dogs have been proven as primary hosts of the parasite. Cases of cutaneous leishmaniasis in humans caused by Leishmania mexicana have been reported in Sinaloa; however, the vectors and hosts involved in the epidemiology of the parasite in northwestern Mexico are still unknown. Given the public health implications of this parasite's domestic hosts regarding the permanence and transmission of the disease to humans, the objective of the present study was to detect and determine the species of Leishmania that caused the first three cases of autochthonous canine leishmaniasis in the state of Sinaloa, Mexico. Three domestic dogs showing symptoms similar to canine leishmaniasis were identified, including chronic eye inflammation, corneal opacity, ocular exudate, emaciation and hyporexia. DNA was extracted from venous blood of the infected animals using a commercial kit. The internal transcribed spacer (ITS-1) of ribosomal DNA (rDNA) was amplified by specific primers for Leishmania from the extracted DNA, and the PCR products were digested with the restriction enzyme HaeIII. In addition, PCR products were subjected to automated sequencing. Molecular analysis showed that the infecting species was L. mexicana. This is the first report of autochthonous canine leishmaniasis caused by L. mexicana in Sinaloa, Mexico. Further studies are required to identify the species that serve as vectors and other wild and domestic hosts of the parasite, as well as to determine if there are more species of Leishmania circulating in Sinaloa.

Película lagrimal: estructura y funciones

A vestige of the evolving forms of aquatic life to terrestrial life is the lacrimal system and its main function is to prevent dryness of the anterior segment of the eye to allow their operation in the Earth’s environment. The product of this system is already in tears and the 5th century BC, Hippocrates recognized its importance. This thin film is very versatile and has great ability to adapt to the changing environment, but when conditions are adverse, it may become fragile and reduce its functionality exposing the eye to potential damage. Understanding the structure of the tear film is necessary to differentiate its normal operation of the anomalous, which would lead to a more accurate diagnosis of the lacrimal alterations. It detailed the parties for the meniscus fringe of the eyelids and tear film itself, given its importance in the integrity and corneal eye. The objective of this thematic review is to describe different theories proposals on the structure and functions of the tear film, as the foundation for the understanding of their clinical performance.

Epistasis between Pax6Sey and genetic background reinforces the value of defined hybrid mouse models for therapeutic trials

The small eye (Sey) mouse is a model of PAX6-aniridia syndrome (aniridia). Aniridia, a congenital ocular disorder caused by heterozygous loss-of-function mutations in PAX6, needs new vision saving therapies. However, high phenotypic variability in Sey mice makes development of such therapies challenging. We hypothesize that genetic background is a major source of undesirable variability in Sey mice. Here we performed a systematic quantitative examination of anatomical, histological, and molecular phenotypes on the inbred C57BL/6J, hybrid B6129F1, and inbred 129S1/SvImJ backgrounds. The Sey allele significantly reduced eye weight, corneal thickness, PAX6 mRNA and protein levels, and elevated blood glucose levels. Surprisingly, Pax6Sey/Sey brains had significantly elevated Pax6 transcripts compared to Pax6+/+ embryos. Genetic background significantly influenced 12/24 measurements, with inbred strains introducing severe ocular and blood sugar phenotypes not observed in hybrid mice. Additionally, significant interactions (epistasis) between Pax6 genotype and genetic background were detected in measurements of eye weight, cornea epithelial thickness and cell count, retinal mRNA levels, and blood glucose levels. The number of epistatic interactions was reduced in hybrid mice. In conclusion, severe phenotypes in the unnatural inbred strains reinforce the value of more naturalistic F1 hybrid mice for the development of therapies for aniridia and other disorders.

Five-Year Changes of Anterior Corneal Indices in Diabetics versus Non-Diabetics: The Shahroud Eye Cohort Study

ABSTRACTPurpose: To compare 5-year changes of central and peripheral corneal thickness, corneal volume, and keratometry between diabetic and non-diabetic individuals (>40 years) in a population-based study.Materials and Methods: Right eye corneal indices of the 333 diabetic persons were compared with 2865 non-diabetics. Studied indices included the apical corneal thickness (ACT), minimal corneal thickness (MCT), thickness values on corneal rings of 4 mm, 6 mm, and 8 mm in diameter, the volume of the 10 mm of the corneal diameter, and the central 3 mm keratometry in two steep (Kmax) and flat (Kmin) axes as measured with Pentacam (Oculus, Inc, Lynnwood, WA).Results: In the diabetic and non-diabetic groups, respectively, the 5-year change was +0.1 ± 11.9 and −1.2 ± 11.9 μm (p = 0.035) for ACT, −1.1 ± 12.1 and −2.4 ± 11.9 μm (p = 0.056) for MCT, −3.9 ± 12.6 and −5.1 ± 12.3 μm (p = 0.007) for the 4 mm ring, −5.0 ± 15.3 and −7.5 ± 14.5 μm (p = 0.006) for the 6 mm ring, and −7.0 ± 20.1 and −10.8 ± 19.2 μm (p = 0.011) for the 8 mm ring. The diabetic group showed less reduction in corneal volume (−0.5 ± 1.8 mm3) compared to non-diabetics (−0.8 ± 1.6 mm3) (p = 0.030). Kmax (+0.3 ± 0.5D vs. +0.4 ± 0.5, p = 0.028) and Kmin (+0.4 ± 0.5D vs. +0.5 ± 0.5, p = 0.005) showed less change in diabetics compared to non-diabetics.Conclusions: The overall patterns of change in corneal thickness and shape in over 40-year old diabetics are similar to non-diabetics, such that with aging, reduced thickness and increased keratometry take the cornea towards a prolate shape. However, the age-related changes in central and peripheral corneal thickness, volume and corneal shape are less pronounced in diabetic subjects.

Association between Skin Thickness Measurements with Corneal Biomechanical Properties and Dry Eye Tests in Systemic Sclerosis

ABSTRACTPurpose: To analyse the association between skin score with corneal biomechanics and dry eye tests in systemic sclerosis (SSc).Methods: 112 cases (limited SSc (lcSSc), n=50; diffuse SSc (dcSSc), n=32; controls, n=30) were included in the study. Corneal hysteresis (CH), corneal resistance factor (CRF), Schirmer 1, 2 tests, OSDI score and modified Rodnan skin score (mRSS) were evaluated.Results: There was correlation between the mRSS and CH (p = 0.004, r = −0.402; p < 0.001, r = -0.786, respectively) as well as correlation with the CRF (p < 0.001, r = 0.709; p < 0.001, r = 0.848, respectively) and OSDI (p < 0.001, r = 0.74; p < 0.001, r = 0.89, respectively) score in lcSSc and dcSSc. Also, the Schirmer 1 (p < 0.001, r = -0.802) and 2 (p < 0.001, r = -0.587) test values showed correlation with the mRSS in dcSSc.Conclusion: Skin score had clinically significant importance for predicting corneal biomechanical properties and dry eye tests in both lcSSc and dcSSc.

Comparison of Contact Lens Hygiene Compliance and Self-Management Behaviors between Medical and Non-Medical Students in Saudi Arabia

Background: Contact lenses are commonly worn by young population for many purposes such as vision correction, cosmetic causes and as a fashion trend. Although wearing contact lens is safe and does not require expertise but it can cause serious eye infections and corneal ulcers, sometimes resulting into loss of vision. The study is designed to com-pare and observe the contact lens hygiene compliance and self-management behavior with a focus on the contact lens wearing habits, cleaning and maintenance of contact lens by different methods and self-prescription between the medical and non-medical students of the Saudi Arabia. Methods: Five hundred young contact lens wearers with an average age of 18-22 years were selected conveniently from the student population of Princess Nourah Bint Abdulrahman University, Riyadh. After taking informed consent from the participants, their level of contact lens hygiene compliance and self-management was assessed by using a peer-reviewed questionnaire. Results: The mean (±SD) age of the participants was 20.87± 1.696 years. Out of 500 students 37.8% were medical and 62.2% were non-medical students. 56% students were wearing contact lens for the cosmetic reasons while 43.6% students were using it for the correction of their myopic refractive error. Most of the students were using daily wear soft contact lenses (96.6%) by self-prescription (51.4%) and majority of them were buying them from general retail store (83.6%) instead of some proper optician. The self-management behavior was statistically significant among nonmedical students (p=0.026). There was no significant difference between the two groups regarding the compliance of the contact lens hygiene but the knowledge and awareness about the risks and complications was statistically high in the medical students (p= 0.028). Most of the students in our study had rated them as an average wearer. Conclusion: This study concludes that self-management with the contact lens use is very common among the nonmedical students of Saudi Arabia. Although they are good in the lens hygiene compliance but their knowledge about the risks and complications of contact lens use and the lens care accessories was significantly low.

Toxicity of silicon dioxide nanoparticles with varying sizes on the cornea and protein corona as a strategy for therapy

The human cornea is exposed directly to particulate matter (PM) in polluted air. This exposure can cause eye discomfort and corneal injury. Ultrafine PM (diameter <100 nm) is thought to be particularly harmful to health, but there is limited research investigating its toxicity to the eye. In this study, we evaluated toxicity differences among 30-, 40-, 100- and 150-nm silicon dioxide nanoparticles (SiO2 NPs) on the cornea. A 24-hour in vitro exposure of primary human corneal epithelial cells (hCECs) to ultrafine (30 and 40 nm) SiO2 NPs produced toxicity, as evidenced by cell membrane damage, reduced cell viability, increased cell death and mitochondrial dysfunction. In vivo exposure to the same nanoparticles produced observable corneal injury. These effects were more severe with ultrafine than with fine (100 and 150 nm) SiO2 NPs. Common antioxidant compounds, e.g., glutathione, did not protect the cornea from SiO2 NP-induced damage. However, foetal bovine serum (FBS) did significantly reduce toxicity, likely by forming a protective protein corona around the nanoparticles. This finding suggests that FBS (or its derivatives) may be a useful clinical therapy for corneal toxicity caused by ultrafine particulates.