Eye Surface Research Articles

Ontogenesis of the Mouse Ocular Surface Lymphatic Vascular Network.

Ocular lymphatic vessels play major physiological role in eye homeostasis and their dysfunction can contribute to the progression of several eye diseases. In this study, we characterized their spatiotemporal development and the cellular mechanisms occurring during their ontogenesis in the mouse eye. Whole mount immunofluorescent staining and imaging by standard or lightsheet fluorescence microscopy were performed on late embryonic and early postnatal eye mouse samples. We observed that the ocular surface lymphatic vascular network develops at the early postnatal stages (between P0 and P5) from two nascent trunks arising at the nasal side on both sides of the nictitating membrane. These nascent vessels further branch and encircle the whole eye surface by sprouting lymphangiogenesis. In addition, we got evidence for the existence of a transient lymphvasculogenesis process generating lymphatic vessel fragments that will mostly formed the corneolimbal lymphatic vasculature which further connect to the conjunctival lymphatic network. Our results also support that CD206-positive macrophages can transdifferentiate and then integrate into the lymphatic neovessels. Several complementary cellular processes participate in the development of the lymphatic ocular surface vasculature. This knowledge paves the way for the design of new therapeutic strategies to interfere with ocular lymphatic vessel formation when needed.

The effect on m6A methylation writer complex by the reduced MATR3 in pterygium

Pterygium is a common eye surface disease with high recurrence and unclear pathogenesis. In current study, RNA sequencing was conducted in 6 pairs of human pterygium and conjunctival tissues, and Matr3 as a novel candidate gene was significantly reduced in pterygium compared to control tissues. Moreover, immunoprecipitation was performed to pull down MATR3, and WTAP specially interacting with MATR3 in control but not pterygium was identified by mass spectrum. Immunoprecipitation was performed to validate the interaction between MATR3 and WTAP/METTL3/METTL14 complex. (Methylated) RNA immunoprecipitation was performed to further reveal that the binding affinity of WTAP and MATR3 was lost at 3′ UTR of RNA molecules of down-regulated genes in pterygium. Overall, we figured out the loss of intercrossing between MATR3 and N6-methyladenosine methyltransferase complex, as well as indicated the potential impact on transcription of target genes in pterygium.

О микробиоме глазной поверхности

The latest molecular biology methods, in particular, bacterial 16S rRNA sequencing, makes it possible to reveal the diversity of the ocular surface microbiota and expand the list of the most common types identified by cultural methods. Most metagenomic sequencing results confirm that Corynebacterium, Propionibacterium, and Staphylococcus are dominant on the healthy ocular surface. However, the obtained data point to differences in the microbial spectrum among people. Factors explaining this variability are currently unknown, in particular, to what extent it is related to people and their environment, and to what extent they are artificial, i.e. brought in from outside. Describing the microorganisms on the ocular surface is not easy due to the possible risk of bacterial contamination. More research is needed, including better experimental studies, to avoid bias in the study of the role of the ocular surface microbiome in relation to healthy and pathological conditions. In particular, the study of strain heterogeneity, overlaps, taxonomic composition and functional profile of the healthy eye surface microbiome are important for drug development, especially those based on probiotics, for the treatment of eye diseases. Key words: ocular surface of a healthy person, ocular microbiome, ocular microbiota, microbial flora, cultural method, identification by the 16S rRNA marker gene, metagenomic sequencing

Measurement of 238 U, 232 Th, 222 Rn and 220 Rn Contents in Optical Contact Lenses: Resulting Alpha and Beta Equivalent Doses to the Eye Tissues of Adult Patients.

To estimate equivalent doses received by eye tissues of patients, contents of uranium ( 238 U), thorium ( 232 Th), radon ( 222 Rn), and thoron ( 220 Rn) were determined inside various optical contact lenses used for vision correction. 238 U, 232 Th, 222 Rn, and 220 Rn contents varied between (3.44 ± 0.24) mBq kg -1 and (18.3 ± 1.28) mBq kg -1 , (0.57 ± 0.04) mBq kg -1 and (3.53 ± 0.25) mBq kg -1 , (3.44 ± 0.24) mBq kg -1 and (18.3 ± 1.28) mBq kg -1 , and (0.57 ± 0.04) mBq kg -1 and (3.53 ± 0.25) mBq kg -1 , respectively. New external dosimetric models, depending on the cornea eye surface of patients, 238 U, 232 Th, and 222 Rn concentrations inside optical contact lenses, half-life of the emitting radionuclides, and exposure time of patients, have been developed. It has been shown that alpha-particles emitted by the 238 U and 232 Th series inside the studied optical lenses transfer their energies essentially to the cornea tissues whereas the emitted beta-particles may reach and lose their energies in the crystalline lens of eyes of patients. Alpha-equivalent doses received by eye tissues of patients due to the diffusion of 222 Rn and 220 Rn gases present in the considered optical lenses were determined. The higher value of the total (alpha plus beta) equivalent dose to the left and right eyes of adult patients wearing optical contact lenses (14 hours per day) has been found equal to 1.32 mSv y -1 cm - 2 . It is recommended for patients to reduce the wearing period of optical contact lenses to reduce eye disease risks such as cataract.

It's cool to be stressed: Body surface temperatures track sympathetic nervous system activation during acute stress.

The acute stress response can be considered the primary evolutionary adaptation to maximise fitness in the face of unpredictable environmental challenges. However, the difficulties of assessing physiology in natural environments mean comparatively little is known about how response variation influences fitness in free-living animals. Currently, determining acute stress physiology typically involves blood sampling or cardiac monitoring. Both require trapping and handling, interrupting natural behaviour, and potentially biasing our understanding toward trappable species/individuals. Importantly, limits on repeated sampling also restrict response phenotype characterisation, vital for linking stress with fitness. Surface temperature dynamics resulting from peripheral vasomotor activity during acute stress are increasingly promoted as alternative physiological stress indicators, which can be measured non-invasively using infrared thermal imaging, overcoming many limitations of current methods. Nonetheless, which aspects of stress physiology they represent remains unclear, as the underlying mechanisms are unknown. To date, validations have primarily targeted the hypothalamic-pituitary-adrenal axis, when the sympathetic-adrenal-medullary (SAM) system is likely the primary driver of vasomotor activity during acute stress. To address this deficit, we compared eye and bill region surface temperatures - measured using thermal imaging - with SAM system activity - measured as heart-rate-variability via electrocardiogram telemetry - in wild-caught captive house sparrows (Passer domesticus), during capture and handling. We found lower body surface temperatures were associated with increased sympathetic nervous system activation. Consequently, our data confirm body surface temperatures can act as a proxy for sympathetic activation during acute stress, providing potentially transformative opportunities for linking the acute stress response with fitness in the wild.

Inflammatory bowel disease and the associated risk of dry eye and ocular surface injury: a nationwide matched cohort study

BackgroundInflammatory bowel disease (IBD) is associated with lacrimal gland dysfunction and ocular inflammation. The objective of this research was to elucidate the temporal relationships between IBD, dry eye disease (DED), and corneal surface damage.MethodsIn a matched nationwide cohort study, we evaluated the risk of DED and corneal surface damage associated with IBD. Multivariable Cox proportional hazards regression analyses were implemented to estimate the risk of ocular complications.ResultsA total of 54,293 matched pairs were included for analyses. The median follow-up time was 8.3 years (interquartile range: 5.5 – 10.5). The period incidence of DED was 8.18 and 5.42 per 1000 person-years in the IBD and non-IBD groups, respectively. After adjusting for confounders, statistically significant associations were found between IBD and DED [adjusted hazard ratio (aHR): 1.43, 95% confidence interval (CI): 1.35 – 1.51, p < 0.0001], Sjögren’s syndrome-related (aHR: 1.67, 95% CI:1.46 – 1.90, p < 0.0001) and non-Sjögren’s syndrome-related subtypes (aHR: 1.38, 95% CI: 1.30 – 1.46, p < 0.0001). Furthermore, increased risks of corneal surface damage (aHR: 1.13, 95% CI: 1.03 – 1.24, p = 0.0094) among the patients with IBD were observed when compared with the controls. Other independent factors associated with corneal surface damage were age (aHR: 1.003), sex (male vs. female, aHR: 0.85), and monthly insurance premium (501–800 vs. 0–500 U.S. dollars, aHR: 1.45; ≥ 801 vs. 0–500 U.S. dollars, aHR: 1.32).ConclusionsOur results suggested that IBD was an independent risk factor for DED and ocular surface damage. Clinical strategies are needed to prevent visual impairment or losses in these susceptible patients.

Multi-camera optical tracking and fringe pattern analysis for eye surface profilometry in ocular proton therapy

Background and purposeAn optical tracking system for high-precision measurement of eye position and orientation during proton irradiation of intraocular tumors was designed. The system performed three-dimensional (3D) topography of the anterior eye segment using fringe pattern analysis based on Fourier Transform Method (FTM). Materials and methodsThe system consisted of four optical cameras and two projectors. The design and modifications to the FTM pipeline were optimized for the realization of a reliable measurement system. Of note, phase-to-physical coordinate mapping was achieved through the combination of stereo triangulation and fringe pattern analysis. A comprehensive pre-clinical validation was carried out. Then, the system was set to acquire the eye surface of patients undergoing proton therapy. Topographies of the eye were compared to manual contouring on MRI. ResultsPre-clinical results demonstrated that 3D topography could achieve sub-millimetric accuracy (median:0.58 mm) and precision (RMSE:0.61 mm) in the clinical setup. The absolute median discrepancy between MRI and FTM-based anterior eye segment surface reconstruction was 0.43 mm (IQR:0.65 mm) ConclusionsThe system complied with the requirement of precision and accuracy for image guidance in ocular proton therapy radiation and is expected to be clinically tested soon to evaluate its performance against the current standard.

The results of a laboratory and clinical study evaluating the disinfecting properties multifunctional solution “OKVision GOLD” in relation to gas-permeable lenses

Introduction. The modern realities of the Russian market of contact lens care products dictate the search for a universal solution for one-stage cleaning, which has high disinfecting and cleansing properties for all types of contact lens materials.Purpose: investigation of the disinfecting properties of the multifunctional solution “OKVision GOLD” in relation to scleral gas-permeable lenses.Materials and methods. 20 patients (40 eyes) with keratoconus of various stages (average age 32.6 ± 2.3 years) were examined before and after wearing scleral lenses in the daytime. A clinical ophthalmological study was conducted, including a biomicroscopic assessment of the lens surfaces, as well as the anterior segment of the eye with the use of vital dyes before and after lens cleaning. In addition, smears were collected for further bacteriological examination. Evaluated: a) initial smear from the conjunctiva of the patient before putting on the contact lens; b) a smear from two surfaces of the lens after wearing it for 12 hours; c) a smear from two surfaces of the lens after 6 hours of treatment in solution. The place of analysis: G.N. Gabrichevsky research institute for epidemiology and microbiology.Results. Sowing smears from the conjunctiva before using contact correction revealed the presence of opportunistic flora. Sowing after 12 hours of wearing lenses determined the attachment of pathogenic flora. Examination of smears from lens surfaces after their 6-hour exposure in solution revealed complete inactivation of previously detected pathogenic and insignificant presence of conditionally pathogenic flora. During biomicroscopy, the condition of the eye surface remained unchanged, no deposits on the lenses were recorded. The survey of patients also revealed no negative reactions.Conclusion. The results of clinical and bacteriological studies indicate high disinfecting activity against conditionally pathogenic and conditionally pathogenic flora in the treatment of scleral lenses. This solution can be recommended for the care of all types of contact lenses, including gas-permeable ones.

Экспериментальное исследование биодеградации синтетических полимерных матриц как перспективных подложек для лимбальных стволовых клеток

Aim. To study in experimental conditions and conduct a comparative assessment of the terms of biodegradation of three different types of synthetic polyester matrices as promising carriers of limbal stem cells. Material and methods. We performed matrices from poly(lactide-glycolide) (PLG), poly(lactide-caprolactone) (PLC) and poly(ε-caprolactone) (PCL). On the basis of the S.M. Kirov Military Medical Academy (St. Petersburg) estimated the timing of the biodegradation of matrices from the PLG, PLC and PCL with a thickness of 5; 10 and 15 microns by binding in vitro to the ocular surface of laboratory animals. Results. During the study, the terms of biodegradation of matrices from PLG, PLC and PCL of various thickness were studied. The time of complete biodegradation of PCL matrices with a thickness of 5 μm was about 30 days, which is the most acceptable for the purpose of their transplantation to the eye surface. Conclusion. The obtained results indicate the possibility of using PLC as a material for the manufacture of matrix carriers with a thickness of 5 μm for the cultivation and transplantation of limbal stem cells. Keywords: poly (lactide-glycolide), poly (lactide-caprolactone), poly (ε-caprolactone), biodegradation, limbal stem cells.

Alterations of the bacterial ocular surface microbiome are found in both eyes of horses with unilateral ulcerative keratitis.

Next generation sequencing (NGS) studies in healthy equine eyes have shown a more diverse ocular surface microbiota compared to culture-based techniques. This study aimed to compare the bacterial ocular surface microbiota in both eyes of horses with unilateral ulcerative keratitis (UK) with controls free of ocular disease. Conjunctival swabs were obtained from both ulcerated eyes and unaffected eyes of 15 client-owned horses with unilateral UK following informed consent, as well as from one eye of 15 healthy horses. Genomic DNA was extracted from the swabs and sequenced on an Illumina platform using primers that target the V4 region of bacterial 16S rRNA. Data were analyzed using Quantitative Insights Into Molecular Ecology (QIIME2). The ocular surface of ulcerated eyes had significantly decreased species richness compared with unaffected fellow eyes (Chao1 q = 0.045, Observed ASVs p = 0.045) with no differences in evenness of species (Shannon q = 0.135). Bacterial community structure was significantly different between either eye of horses with UK and controls (unweighted UniFrac: control vs. unaffected, p = 0.03; control vs. ulcerated, p = 0.003; unaffected vs. ulcerated, p = 0.016). Relative abundance of the gram-positive taxonomic class, Bacilli, was significantly increased in ulcerated eyes compared with controls (q = 0.004). Relative abundance of the taxonomic family Staphylococcaceae was significantly increased in ulcerated and unaffected eyes compared with controls (q = 0.030). The results suggest the occurrence of dysbiosis in infected eyes and reveal alterations in beta diversity and taxa of unaffected fellow eyes. Further investigations are necessary to better understand the role of the microbiome in the pathophysiology of ocular surface disease.

Biomimetic Compound Eyes with Gradient Ommatidium Arrays.

Compound eyes are high-performing natural optical perception systems with compact configurations, generating extensive research interest. Existing compound eye systems are often combinations of simple uniform microlens arrays; there are still challenges in making more ommatidia on the compound eye surface to focus to the same plane. Here, a biomimetic gradient compound eye is presented by artificially mimicking dragonflies. The multiple replication process efficiently endows compound eyes with the gradient characteristics of dragonfly compound eyes. Experimental results show that the manufactured compound eye allows multifocus imaging by virtue of the gradient ommatidium array arranged closely in a honeycomb pattern while ensuring excellent optical properties and compact configurations. Thousands of ommatidia showing a gradient trend at the millimeter scale while remaining relatively uniform at the micron scale have gradient focal lengths ranging from 260 to 450 μm. This gradient compound eye allows more ommatidia to focus on the same plane than traditional uniform compound eyes, which have experimentally been shown to capture more than 1100 in-plane clear images simultaneously, promising potential applications in micro-optical devices, optical imaging, and biochemical sensing.

Cellular toxicity profile of a new ophthalmic sponge

Introduction: Ophthalmic sponges are used for cleaning the eye surface and absorbing fluids during ophthalmic procedures. This study compared the biological safety and stability of a new ophthalmic sponge, Occucell® (OccuTech Inc, Seongnam, Korea), on the human conjunctival epithelial cells with those of preexisting products to evaluate its clinical application. Materials and Methods: The cytotoxicity of four products, Occucell, a new product, Ultracell®, Eyetec-1, and Eyetec-2, on conjunctival epithelial cells, was evaluated using the MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) analysis. Additionally, human conjunctival epithelial cells were stained with a Live & Dead marker and observed using a fluorescence microscope. To evaluate the effect of the ophthalmic sponges on the secretion of IL-1β and TNF-α, cultured conjunctival epithelial cells were treated with 0.5% DMSO eluates of the ophthalmic sponges, and IL-1β and TNF-α mRNA levels were estimated using real-time polymerase chain reaction assays. Results: Cells treated with Occucell showed comparable viability to those treated with other preexisting products. Conjunctival epithelial cells showed more than 90% viability when treated with the ophthalmic sponge extracts, as determined by the MTT assay. No significant differences in the number of live & dead cells were observed between the control and treatment groups. Cells treated with all four ophthalmic sponge eluates showed similar IL-1β and TNF-α mRNA levels. Discussion: Occucell, an eye sponge used during ophthalmic surgery in clinical practice, did not affect the viability of conjunctival epithelial cells, and more than 90% of the cells were viable after the treatment. Further, Occucell showed similar effects on IL-1β and TNF-α secretion as that of other ophthalmic sponges used in the clinic. This suggested that Occucell is a safe product comparable to the preexisting products.

Advances in clinical examination of lacrimal gland.

In humans, the lacrimal gland is located in the socket of the frontal bone above the outer orbital area. As an essential part of the eye surface, the gland is fixed to the orbital periosteum by connective tissue. The lacrimal gland passes through the outer tendon membrane, which divides the gland into larger orbital and minor eyelid glands. The lacrimal glands are the main contributors to tear film. They secrete electrolytes, proteins, and water to help nourish and protect the eye's surface. Furthermore, clinically, lacrimal glands are associated with a variety of inflammatory reactions and immune factors and are also vulnerable sites for tumors. Changes in tear gland morphology or secretory function affect tear film stability and tear secretion quality. Various technological devices have been developed and applied to lacrimal glands. This article systematically reviewed the clinical examination of the lacrimal gland to help inform personalized strategies for the diagnosis of lacrimal gland-related diseases.

Association Between Screen Time and Tear Film Stability

Tear film is a layer that nourishes, lubricates and protects the anterior surface of eye. The usage of electronic gadgets can affect the tear film stability causing ocular dryness. Recently, due to the increased frequency of online educational and leisure activities, there has been reported increase in the prevalence of dry eye among users of electronic gadgets. Objective: To evaluate association between screen time and stability of tear film. Methods: A descriptive cross-sectional study was conducted from January to august 2021 at The University of Lahore. 120 participants aged above 18 years were recruited using nonprobability sampling technique. After taking consent from the participant’s questionnaire was completed, followed by slit lamp examination for evaluation tear film breakup time (TBUT). Results: 120 healthy people of either gender who were at least 18 years old participated in this study, selected through random sampling, informed consent was acquired from all participants. The TBUT test was performed on all subjects, 74 had severe dry eyes, 21 had moderate dry eyes, and just 24 had normal eyes. Each subject's screen time was tracked after the subjects were divided into four groups. The Chi square was used to assess the relationship between screen time and tear film break up time. Results had a p value less than 0.01 and were statistically significant. Conclusions: This study concluded that as the screen time increases it effects the stability of tear film.

1301 What Can Be Done to Minimise the Mucosal Complications of Surgical Intervention Involved in the Treatment of Corneal Blindness Through Osteo-Odonto-Keratoprosthesis

Abstract Introduction Osteo-odonto-keratoprosthesis (OOKP), “tooth-in-eye surgery”, is a rare, complex surgery offered to certain patients with bilateral corneal blindness. Indications for the surgery include and range from: Steven-Johnson syndrome to end-stage ocular surface diseases. OOKP consists of two stages undertaken four months apart. Surgical complications can be divided into intraoperative and following stages 1 and 2. The most common postoperative complications include: Mucosal thinning/ulceration, mucosal overgrowth, and infection. We discuss, preventive methods which can be considered before the stage 2 intervention to minimise the rate of complications post OOKP surgery. Method A literature search was conducted in PubMed and Research gate to determine the main complications following involvement of maxillofacial surgery. Our key search criteria included mucosal complications post maxillofacial and oculoplastic surgical involvement. We selected for complications, post harvestation and transfer of the buccal mucosa onto the eye surface in OOKP. Results Three studies were selected, with a total of 130 patients. 58% experiencing surgical complications following stage 2. Study 1 demonstrated mucosal graft complications (22%), mucosal overgrowth(28%), mucosal thinning and ulceration(22%). Notably, 38% experienced no complications following the second stage. In the remaining studies, post-operative complications were divided into mucosal necrosis (33%) and mucosal overgrowth(13%), showing how complications can often interplay. Conclusions OOKP is a complex and laborious multi-disciplinary surgery, amenable to postoperative complications. Mucosal complications occur in a significant number of cases; therefore, it is important to anticipate these and endeavour to avert them. We outline how through prudent patient selection and pre-operative patient care (promotion and correction of dentition and oral health, examination of oral mucosa and maintenance of good mucosal graft health), outcomes for this surgery can be significantly improved.

High‐Density Lipoprotein Engineering for Eye‐Drop Treatment of Age‐Related Macular Degeneration

AbstractEye‐drop treatments of age‐related macular degeneration (AMD) are desirable; however, no clinically approved eye drop has been reported to date. This study aim to evaluate the therapeutic activity of eye‐drop instillation of a high‐density lipoprotein (HDL) variant bearing a cell‐penetrating peptide and neovasculature‐targeted peptide (AsnGlyArg [NGR] peptide) in a mouse model at a dose of 0.6–0.85 µg protein/eye drop. The results reveal that the activity of the abovementioned variant was &gt;10‐fold higher than that of the previous variant lacking an NGR peptide. In addition, the anti‐inflammatory activity, cholesterol‐efflux capacity, and antiangiogenic activity of reconstituted HDL are significantly augmented by the attachment of these two peptides. The mechanism underlying this dramatic improvement is likely the expression of CD13, an NGR peptide receptor, on the cornea and conjunctiva in mice. CD13 mRNA/protein expression is also detected in cultured human corneal and conjunctival cells. These results demonstrate that NGR peptide is an unprecedented class of an absorption enhancer on the eye surface. Thus, HDL engineering is a potential strategy for developing eye drops to treat neovascular AMD by enhancing the ocular surface absorption and HDL functionalities.

Pathological analysis and antimicrobial susceptibility of Chryseobacterium balustinum RTFCP 298 isolated from diseased rainbow trout, Oncorhynchus mykiss

In this study, six isolates of Chryseobacterium balustinum were characterized from diseased rainbow trout fingerlings. The virulence characteristics, pathogenicity, and antimicrobial susceptibility pattern of these isolates were investigated. The bacterium showed positive results for catalase, cytochrome oxidase, and aesculin hydrolysis, while negative results were obtained for DNase, gelatinase, methyl red, Voges-Proskauer's reaction, Simon citrate, Hydrogen sulphide, and starch hydrolysis. Amino acid metabolism analysis revealed the inability to metabolize arginine, lysine, and ornithine decarboxylase. Molecular characterization (16S rRNA) and phylogenetic analysis revealed the test isolates as C. balustinum, closely related to strain WLT (99.85% similarity) and C. balustinum P-27 (99.77%). Virulence assay indicated haemolytic activity and biofilm formation by the test bacterium. The challenge test confirmed moderate pathogenicity in rainbow trout and established Koch's postulates. The clinical manifestations of infection included fin erosion, eye and body surface haemorrhage, exophthalmia, and organ liquefaction. The minimum inhibitory concentrations of various antimicrobials ranged from 1 to > 256 µg mL−1. The novel synthetic antimicrobial peptides exhibited MICs of 8 to > 256 µg mL−1, suggesting a potential control method. These findings suggest that C. balustinum is an opportunistic pathogen with moderate pathogenicity in rainbow trout. Further research on the host–pathogen relationship is necessary to understand virulence characteristics and pathogenicity in aquaculture.

Inhibition of anterior capsule opacification and contraction by the elevated anterior rim of the intraocular lens optic.

To verify the anterior capsule opacification (ACO) and contraction (ACC) of the ZCB00V intraocular lens (IOL), made of the same material as the AR40e with a high ACC rate. Retrospective cohort study. We evaluated 35 patients at 1 week, 1, 3 and 6 months post phacoemulsification with either a ZCB00V (n = 35) or FY-60AD (n = 34) IOL implantation. The ACC rate was calculated using retroillumination images of the anterior segment, and the ACO was measured using anterior segment photographs and image analysis software. The contact grade between the IOL and anterior capsule was estimated from the Pentacam® images. The postoperative ACC rates (mean ± standard deviation) at 3 months were 1.03%±2.54% for the ZCB00V and, and 7.12%±9.47% for the FY-60AD. The ZCB00V-implanted eyes showed a significantly lower postoperative ACC at 1 week, 3 months, and 6 months (P < 0.01). On the other hand, the FY-60AD-implanted eyes had more pronounced ACO, and a significantly larger area of opacification (62.24%±21.32% vs. 16.90%±8.34%; P = 0.0005). Pentacam® analysis revealed a space between the anterior capsule and IOL surface in the ZCB00V-implanted eyes, whereas the anterior capsule firmly adhered to the IOL surface in the FY-60AD-implanted eyes. The ACC and ACO were significantly lower in eyes with ZCB00V IOLs compared to those with the FY-60AD. The anterior segment image analysis revealed that the elevated anterior rim of the ZCB00V IOL prevented adhesion between the anterior capsule and IOL optic surface, suggesting an open capsule effect.

A Physiology-Based Mathematical Model to Understand Drug Delivery from Contact Lenses to the Back of the Eye.

Therapeutic contact lenses, able to store drug and deliver it to the eye surface in a sustained fashion, gained interest as an effective and patient-friendly alternative to eye drops. Recent animal studies also demonstrated the presence of therapeutic drug levels in the back of the eye after wearing drug-loaded contact lenses, thus opening the possibility of treating the posterior segment without need of invasive intraocular injections. The drug pathways from contact lenses to the back of the eye require further investigation. A mechanistic mathematical model was developed to evaluate the drug concentration over time in the tears, sclera and choroid, retina, aqueous humor and vitreous humor after the application of a therapeutic contact lens. The main drug transport mechanisms of the eye and the barrier properties of the different tissues were included in the model. Validation was performed by comparison with experimental data in literature. The model predictions of drug concentration over time reflected the experimental data both in the anterior and posterior segment of the eye. The model can differentiate between contributions to transport from different pathways. The model constitutes a first step towards the possibility of predicting the ocular drug distribution and the treatment efficacy in the early stage of contact lens development, and it may help reduce both the need for in vivo tests (with ethical and economic advantages) and the gap between the lens design and clinical application. It also allows for an improved understanding of drug transport in the eye.

Ocular Surface Changes in Primary Open Angle Glaucoma Patients Treated With Topical Antihypertensive Drugs.

In this study, patients with glaucoma undergoing topical antihypertensive (TAH) drugs had changes in the ocular surface and more dry eye symptoms than controls. Clinicians should recognize the influence of TAH drops on exacerbating ocular surface disease. The purpose of this study was to evaluate the ocular surface of eyes with glaucoma treated with TAH drugs. Cross-sectional study that included eyes undergoing TAH drugs due to primary open angle glaucoma and controls. The parameters evaluated were: the basal tear flow (basic secretion test); the tear film osmolarity (TearLab); and the noninvasive break-up time, blink score, lipid layer thickness, tear meniscus height, and loss area of the meibomian glands, measured with the IDRA Ocular Surface Analyser. Presence of symptoms [Ocular Surface Disease Index (OSDI)], dry eye disease (DED, TFOS DEWS II criteria), and corneal fluorescein staining were assessed. We included 154 eyes (154 patients), 77 undergoing TAH drugs for glaucoma (group 1) and 77 of controls (group 2). The tear film osmolarity ( P =0.003) and the loss area of the meibomian glands ( P =0.004) were higher in group 1. The noninvasive break-up time ( P =0.005), lipid layer thickness ( P =0.006), and tear meniscus height ( P =0.001) were lower in group 1. The global OSDI score ( P <0.001), the proportion of eyes with severe disease ( P =0.002), according to the OSDI, and with DED ( P <0.001), according to the TFOS DEWS II criteria, were higher in group 1. The proportion of patients with corneal fluorescein staining was higher in group 1 ( P <0.001). There were no significant differences in eyes taking TAH drugs with and without preservatives ( P >0.127). DED, in patients with glaucoma, is a multifactorial disease, with a strong contribution from TAH drugs. These eyes had changes in almost every measured parameter, translating into the presence of more dry eye symptoms and corneal damage when compared with controls.