Nanomedicines for Dry Eye Syndrome: Targeting Oxidative Stress with Modern Nanomaterial Strategies

Dry eye syndrome (DES) is a dynamic, chronic disease of the ocular surface and ocular appendages caused by inflammation. The most common symptoms include redness, itching, and blurred vision, resulting from dysfunction of the meibomian glands and impaired tear-film production. Factors contributing to the development of DES include environmental elements, such as UV radiation, and internal elements, such as hormonal imbalances. These factors increase oxidative stress, which exacerbates inflammation on the surface of the eye and accelerates the development of DES. In recent years, the incidence of DES has risen, leading to a greater need to develop effective treatments. Current treatments for dry eye are limited and primarily focus on alleviating individual symptoms, such as reducing inflammation of the ocular surface. However, it is crucial to understand the pathomechanism of the disease and tailor treatment to address the underlying causes to achieve the best possible therapeutic outcomes. Therefore, in this review, we analyzed the impact of oxidative stress on the development of DES to gain a better understanding of its pathomechanism and examined recently developed nanosystems that allow drugs to be delivered directly to the disease site.

Drug-Modified Contact Lenses-Properties, Release Kinetics, and Stability of Active Substances with Particular Emphasis on Cyclosporine A: A Review

The following review focuses on the manufacturing and parameterizing of ocular drug delivery systems (DDS) using polymeric materials to create soft contact lenses. It discusses the types of drugs embedded into contact lenses, the various polymeric materials used in their production, methods for assessing the mechanical properties of polymers, and techniques for studying drug release kinetics. The article also explores strategies for investigating the stability of active substances released from contact lenses. It specifically emphasizes the production of soft contact lenses modified with Cyclosporine A (CyA) for the topical treatment of specific ocular conditions. The review pays attention to methods for monitoring the stability of Cyclosporine A within the discussed DDS, as well as investigating the influence of polymer matrix type on the stability and release of CyA.

Encapsulation of Cyclosporine A-Loaded PLGA Nanospheres in Alginate Microbeads for Anti-Inflammatory Application

The controlled release of cyclosporine A (CsA) microencapsulated in alginate microbeads is a novel drug delivery system for the treatment of inflammatory diseases. In this study, CsA-loaded nanospheres encapsulated in alginate microbeads were applied to evaluate their controlled release profile and anti-inflammatory activity. Initially, a controlled-release drug delivery system was created by encapsulating CsA-loaded PLGA nanospheres within alginate microbeads. CsA-loaded PLGA nanospheres had a diameter of 418.70 ± 59.08 nm, a zeta potential of -22 ± 0.57 mV, and a polydispersity index of 0.517 ± 0.010. CsA-loaded nanosphere-encapsulated alginate microbeads were stable for 37 days. After encapsulating CsA-loaded PLGA nanospheres in the alginate microbeads, 5.60% of CsA was released after 24 h, and approximately 85.90% of the drugs were diffused until day 64. The cytotoxic and anti-inflammatory properties of the CsA released from the microbeads were evaluated in vitro using a murine macrophage cell line (RAW 264.7 cells). CsA-loaded nanosphere-encapsulated alginate microbeads inhibited 39.47 ± 1.71% of nitric oxide production from the RAW 264.7 cells on day 3, whereas nanosphere-encapsulated alginate microbeads inhibited 18.45 ± 1.56% only. CsA released from CsA-loaded nanosphere-encapsulated alginate microbeads had a RAW cell viability of 82.73 ± 5.58% on day 3 compared to 87.59 ± 0.69% of nanosphere-encapsulated alginate microbeads. The efficacy of the CsA-loaded nanosphere-encapsulated alginate microbeads in protecting the immune system via a controlled drug delivery system was established through anti-inflammatory and cell viability evaluation. Based on this research, the controlled release of CsA-loaded nanosphere-encapsulated alginate microbeads provides an innovative treatment for inflammatory diseases.

Biodegradable Polymer-Based Drug-Delivery Systems for Ocular Diseases

Ocular drug delivery is a challenging field due to the unique anatomical and physiological barriers of the eye. Biodegradable polymers have emerged as promising tools for efficient and controlled drug delivery in ocular diseases. This review provides an overview of biodegradable polymer-based drug-delivery systems for ocular diseases with emphasis on the potential for biodegradable polymers to overcome the limitations of conventional methods, allowing for sustained drug release, improved bioavailability, and targeted therapy. Natural and synthetic polymers are both discussed, highlighting their biodegradability and biocompatibility. Various formulation strategies, such as nanoparticles, hydrogels, and microemulsions, among others, are investigated, detailing preparation methods, drug encapsulation, and clinical applications. The focus is on anterior and posterior segment drug delivery, covering glaucoma, corneal disorders, ocular inflammation, retinal diseases, age-related macular degeneration, and diabetic retinopathy. Safety considerations, such as biocompatibility evaluations, in vivo toxicity studies, and clinical safety, are addressed. Future perspectives encompass advancements, regulatory considerations, and clinical translation challenges. In conclusion, biodegradable polymers offer potential for efficient and targeted ocular drug delivery, improving therapeutic outcomes while reducing side effects. Further research is needed to optimize formulation strategies and address regulatory requirements for successful clinical implementation.

Loteprednol-Loaded Nanoformulations for Corneal Delivery by Quality-by-Design Concepts: Optimization, Characterization, and Anti-inflammatory Activity

Loteprednol etabonate (LE) is a topical corticosteroid that uses inflammatory conditions of the eye. It has a low ocular bioavailability and side effects such as corneal disorder, eye discharge, and ocular discomfort. Therefore, it was decided to select the delivery systems, which are solid lipid nanoparticles (SLN), nanostructured lipid carriers (NLC), and nanoemulsion (NE). Design of experiments (DoE) of SLN, NLC, and NE formulations were formulated by using the quality by design (QbD) approach. Precirol® ATO 5 and oleic acid were used as solid and liquid lipids, respectively, in SLN, NLC, and NE formulations. Physiochemical characterization was performed on the formulations. The optimized formulations' inflammatory effects have been appraised on human corneal epithelial cells employing the ELISA test. Physicochemical characterization studies and inflammatory effects were appraised. The sizes of optimized formulations of SLN, NLC, and NE were 86.19 nm, 82.38 nm, and 126.35 nm, respectively, with minimum polydispersity. The release behavior of the formulations is composed of both diffusion and erosion. ELISA test results proved that the formulations significantly reduced IL-1 and IL-6 levels (p < 0.05). D-optimal mixture experimental design allowed us to develop the most precise formulations of SLN, NLC, and NE. Furthermore, the optimized formulations could be promising candidates for treating an inflammation-based corneal disease of the eye.

Novel drug delivery systems for the management of dry eye

Dry eye disease (DED) is a frequently observed eye complaint, which has recently attracted considerable research interest. Conventional therapy for DED involves the use of artificial tear products, cyclosporin, corticosteroids, mucin secretagogues, antibiotics and nonsteroidal anti-inflammatory drugs. In addition, ocular drug delivery systems based on nanotechnology are currently the focus of significant research effort and several nanotherapeutics, such as nanoemulsions, nanosuspensions, microemulsions, liposomes and nanomicelles, are in clinical trials and some have FDA approval as novel treatments for DED. Thus, there has been remarkable progress in the design of nanotechnology-based approaches to overcome the limitations of ophthalmic formulations for the management of anterior eye diseases. This review presents research results on diagnostic methods for DED, current treatment options, and promising pharmaceuticals as future therapeutics, as well as new ocular drug delivery systems.

Linoleic Acid-Based Transferosomes for Topical Ocular Delivery of Cyclosporine A

Delivering high-molecular-weight hydrophobic peptides, such as cyclosporine A, across the corneal epithelium remains a challenge that is complicated by other physio-anatomical ocular structures that limit the ocular bioavailability of such peptides. Transferosomes have previously been used to improve transdermal permeability, and have the potential for improving the ocular corneal permeability of applicable drugs. In this study, transferosomes for the potential ocular delivery of cyclosporine A were investigated. Linoleic acid was evaluated for its effect on the stability of the transferosomes and was substituted for a portion of the cholesterol in the vesicles. Additionally, Span® 80 and Tween® 80 were evaluated for their effect on transferosome flexibility and toxicity to ocular cells as edge activators. Attenuated Total Reflectance–Fourier Transform Infrared spectroscopy (ATF-FTIR), differential scanning calorimetry (DSC), and dynamic light scattering (DLS) were used to evaluate the physicochemical parameters of the blank and the cyclosporine A-loaded transferosomes. Cyclosporine A release and corneal permeability were studied in vitro and in a New Zealand albino rabbit corneal model, respectively. The linoleic acid contributed to improved stability and the nano-size of the transferosomes. The Tween®-based formulation was preferred on the basis of a more favorable toxicity profile, as the difference in their corneal permeability was not significant. There was an initial burst release of cyclosporine A in the first 24 h that plateaued over one week. The Tween®-based formulation had a flux of 0.78 µg/cm2/h. The prepared transferosomes demonstrated biocompatibility in the ocular cell line, adequately encapsulated cyclosporine A, ensured the corneal permeability of the enclosed drug, and were stable over the period of investigation of 4 months at −20 °C.

Formulation and development of tacrolimus-gellan gum nanoformulation for treatment of dry eye disease

The present study aimed at the development and evaluation of tacrolimus gellan gum nanoparticles (TGNPs) for the effective management of dry eye disease (DED) following topical application. TGNPs were developed by ionotropic gelation between gellan gum and aluminum chloride. Developed TGNPs were nanosized (274.46 ± 8.90 nm) with high % encapsulation efficiency (74.2 ± 2.4%) and loading capacity (36.14 ± 1.7%). The nanosize and spherical morphology of TGNPs was confirmed by transmission electron microscopy (TEM) and atomic force microscopy (AFM). Fourier transform infrared spectroscopy (FTIR) revealed no interaction between drug and GG. Differential scanning calorimetry (DSC) and X-ray diffraction (XRD) confirms the conversion of crystalline tacrolimus to amorphous post encapsulation in the nanoparticle. TGNPs showed prolonged drug release throughout 12 h and higher pre-corneal retention compared to tacrolimus solution. HET-CAM studies, histopathological evaluation, and Draize test confirmed the safety of the formulation for ocular use. Further, the pharmacodynamic studies using experimental DED in rabbits showed that TGNPs are effective in treating symptoms of DED. In conclusion, topical delivery of TGNPs could hold potential for efficient management of DED.

Poly(lactic-co-glycolic acid) Nanoparticles Encapsulating the Prenylated Flavonoid, Xanthohumol, Protect Corneal Epithelial Cells from Dry Eye Disease-Associated Oxidative Stress

Oxidative stress is a known contributor to the progression of dry eye disease pathophysiology, and previous studies have shown that antioxidant intervention is a promising therapeutic approach to reduce the disease burden and slow disease progression. In this study, we evaluated the pharmacological efficacy of the naturally occurring prenylated chalconoid, xanthohumol, in preclinical models for dry eye disease. Xanthohumol acts by promoting the transcription of phase II antioxidant enzymes. In this study, xanthohumol prevented tert-butyl hydroperoxide-induced loss of cell viability in human corneal epithelial (HCE-T) cells in a dose-dependent manner and resulted in a significant increase in expression of the transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2), the master regulator of phase II endogenous antioxidant enzymes. Xanthohumol-encapsulating poly(lactic-co-glycolic acid) nanoparticles (PLGA NP) were cytoprotective against oxidative stress in vitro, and significantly reduced ocular surface damage and oxidative stress-associated DNA damage in corneal epithelial cells in the mouse desiccating stress/scopolamine model for dry eye disease in vivo. PLGA NP represent a safe and efficacious drug delivery vehicle for hydrophobic small molecules to the ocular surface. Optimization of NP-based antioxidant formulations with the goal to minimize instillation frequency may represent future therapeutic options for dry eye disease and related ocular surface disease.

Facilitated and Controlled Strontium Ranelate Delivery Using GCS-HA Nanocarriers Embedded into PEGDA Coupled with Decortication Driven Spinal Regeneration

BACKGROUND AND PURPOSE

Strontium ranelate (SrR) is an oral pharmaceutical agent for osteoporosis. In recent years, numerous unwanted side effects of oral SrR have been revealed. Therefore, its clinical administration and applications are limited. Hereby, this study aims to develop, formulate, and characterize an effective SrR carrier system for spinal bone regeneration.

METHODS

Herein, glycol chitosan with hyaluronic acid (HA)-based nanoformulation was used to encapsulate SrR nanoparticles (SrRNPs) through electrostatic interaction. Afterward, the poly(ethylene glycol) diacrylate (PEGDA)-based hydrogels were used to encapsulate pre-synthesized SrRNPs (SrRNPs-H). The scanning electron microscope (SEM), TEM, rheometer, Fourier-transform infrared spectroscopy (FTIR), and dynamic light scattering (DLS) were used to characterize prepared formulations. The rabbit osteoblast and a rat spinal decortication models were used to evaluate and assess the developed formulation biocompatibility and therapeutic efficacy.

RESULTS

In vitro and in vivo studies for cytotoxicity and bone regeneration were conducted. The cell viability test showed that SrRNPs exerted no cytotoxic effects in osteoblast in vitro. Furthermore, in vivo analysis for new bone regeneration mechanism was carried out on rat decortication models. Radiographical and histological analysis suggested a higher level of bone regeneration in the SrRNPs-H-implanted groups than in the other experimental groups.

CONCLUSION

Local administration of the newly developed formulated SrR could be a promising alternative therapy to enhance bone regeneration in bone-defect sites in future clinical applications.

Cyclosporine Lipid Nanocapsules as Thermoresponsive Gel for Dry Eye Management: Promising Corneal Mucoadhesion, Biodistribution and Preclinical Efficacy in Rabbits

An ophthalmic cyclosporine (CsA) formulation based on Lipid nanocapsules (LNC) was developed for dry eye management, aiming to provide targeting to ocular tissues with long-term drug levels and maximum tolerability. CsA-LNC were of small particle size (41.9 ± 4.0 nm), narrow size distribution (PdI ≤ 0.1), and high entrapment efficiency (above 98%). Chitosan (C) was added to impart positive charge. CsA-LNC were prepared as in-situ gels using poloxamer 407 (P). Ex vivo mucoadhesive strength was evaluated using bovine cornea, while in vivo corneal biodistribution (using fluorescent DiI), efficacy in dry eye using Schirmer tear test (STT), and ocular irritation using Draize test were studied in rabbits compared to marketed ophthalmic CsA nanoemulsion (CsA-NE) and CsA in castor oil. LNC incorporation in in-situ gels resulted in an increase in mucoadhesion, and stronger fluorescence in corneal layers seen by confocal microscopy, compared to the other tested formulations. Rate of recovery (days required to restore corneal baseline hydration level) assessed over 10 days, showed that CsA-LNC formulations produced complete recovery by day 7 comparable to CsA-NE. No Ocular irritation was observed by visual and histopathological examination. Based on data generated, CsA-LNC-CP in-situ gel proved to be a promising effective nonirritant CsA ophthalmic formulation for dry eye management.

Formulation of PPAR-gamma agonist as surface modified PLGA nanoparticles for non-invasive treatment of diabetic retinopathy: in vitro and in vivo evidences

Diabetic retinopathy is one of the worst complications of diabetes and it is treated by invasive method. We prepared a surface modified poly (D, L-lactide-co-glycolide) i.e. PLGA nanoparticles for delivery of pioglitazone-a peroxisome proliferator-activated receptor-gamma agonist to posterior segment of the eye by topical administration. The present study investigated two grades of PLGA viz. 75:25 and 50:50. Surface modification was performed using polysorbate 80. Nanoparticles were prepared by single emulsion solvent evaporation method and optimized by using 3-factor 3-level Box-Behnken statistical design. Mean particle size, PDI and entrapment efficiency for optimized batch of PLGA 75:25 was found to be 163.23 nm, 0.286 and 91%, whereas; for PLGA 50:50 it was 171.7 nm, 0.280 and 93% respectively. DSC confirms the molecular dispersion of drug in polymer. In vitro release study showed biphasic drug release pattern with 58.48 ± 1.38% and 74.17 ± 1.38% cumulative drug release by PLGA 75:25 and 50:50 nanoparticles at the end of 10h. The release profile of pioglitazone from nanoparticles appeared to fit best with Higuchi model. In vivo study on rat showed dose dependent reduction in vascular endothelial growth factor concentration in vitreous fluid. The study reveals significance of peroxisome proliferator-activated receptor-gamma in management of diabetic retinopathy.

The Role of Nano-ophthalmology in Treating Dry Eye Disease

Dry eye disease (DED) is a common multifactorial disease linked to the tears/ocular surface leading to eye discomfort, ocular surface damage, and visual disturbance. Antiinflammatory agents (steroids and cyclosporine A), hormonal therapy, antibiotics, nerve growth factors, essential fatty acids are used as treatment options of DED. Current therapies attempt to reduce the ocular discomfort by producing lubrication and stimulating gland/nerve(s) associated with tear production, without providing a permanent cure for dry eye. Nanocarrier systems show a great promise to revolutionize drug delivery in DED, offering many advantages such as site specific and sustained delivery of therapeutic agents. This review presents an overview, pathophysiology, prevalence and etiology of DED, with an emphasis on preclinical and clinical studies involving the use of nanocarrier systems in treating DED. Lay Summary: Dry eye disease (DED) is a multifactorial disease associated with tear deficiency or excessive tear evaporation. There are several review articles that summarize DED, disease symptoms, causes and treatment approaches. Nanocarrier systems show a great promise to revolutionize drug delivery in DED, offering many advantages such as site specific and sustained delivery of therapeutic agents. Very few review articles summarize the findings on the use of nanotherapeutics in DED. In this review, we have exclusively discussed the preclinical and clinical studies of nanotherapeutics in DED therapy. This information will be attractive to both academic and pharmaceutical industry researchers working in DED therapeutics.

Assembling Surfactants-Mucoadhesive Polymer Nanomicelles (ASMP-Nano) for Ocular Delivery of Cyclosporine-A

The physiological protective mechanisms of the eye reduce the bioavailability of topically administered drugs above all for those with high molecular weight and /or lipophilic characteristics, such as Cyclosporine A (CyA). The combined strategy based on the association of nanomicelles and mucoadhesive polymer seems promising since a limited number of commercial products containing CyA have been recently approved. The scope of this investigation was the design of Assembling Surfactants-Mucoadhesive Polymer Nanomicelles (ASMP-Nano), based on a binary system of two surfactants in combination with hyaluronic acid, and their biopharmaceutical evaluation. The optimisation of the ASMP-Nano in term of the amount of surfactants, CyA-loading and size determined the selection of the clear and stable Nano1HAB-CyA formulation containing 0.105% w/w CyA loaded-nanomicelles with a size of 14.41 nm. The nanostructured system had a protective effect towards epithelial corneal cells with a cell viability of more than 80%. It interacted with cellular barriers favouring the uptake and the accumulation of CyA into the cells as evidenced by fluorescent probe distribution, by hindering CyA permeation through reconstituted corneal epithelial tissue. In pharmacokinetics study on rabbits, the nanomicellar carrier prolonged the CyA retention time in the precorneal area mainly in presence of hyaluronic acid (HA), a mucoadhesive polymer.

Optimising poly(lactic-co-glycolic acid) microparticle fabrication using a Taguchi orthogonal array design-of-experiment approach

The objective of this study was to identify, understand and generate a Taguchi orthogonal array model for the formation of 10-50 μm microparticles with applications in topical/ocular controlled drug delivery. Poly(lactic-co-glycolic acid) (PLGA) microparticles were fabricated by the single emulsion oil-in-water method and the particle size was characterized using laser diffraction and scanning electronic microscopy (SEM). Sequential Taguchi L12 and L18 orthogonal array (OA) designs were employed to study the influence of ten and eight parameters, respectively, on microparticle size (response). The first optimization step using the L12 design showed that all parameters significantly influenced the particle size of the prepared PLGA microparticles with exception of the concentration of poly(vinyl alcohol) (PVA) in the hardening bath. The smallest mean particle size obtained from the L12 design was 54.39 μm. A subsequent L18 design showed that the molecular weight of PLGA does not significantly affect the particle size. An experimental run comprising of defined parameters including molecular weight of PLGA (89 kDa), concentration of PLGA (20% w/v), concentration of PVA in the emulsion (0.8% w/v), solvent type (ethyl acetate), organic/aqeuous phase ratio (1:1 v/v), vortexing speed (9), vortexing duration (60 seconds), concentration of PVA in hardening bath (0.8% w/v), stirring speed of hardening bath (1200 rpm) and solvent evaporation duration (24 hours) resulted in the lowest mean particle size of 23.51 μm which was predicted and confirmed by the L18 array. A comparable size was demonstrated during the fabrication of BSA-incorporated microparticles. Taguchi OA design proved to be a valuable tool in determining the combination of process parameters that can provide the optimal condition for microparticle formulation. Taguchi OA design can be used to correctly predict the size of microparticles fabricated by the single emulsion process and can therefore, ultimately, save time and costs during the manufacturing process of drug delivery formulations by minimising experimental runs.

Dry Eye Disease: A Review of Epidemiology in Taiwan, and its Clinical Treatment and Merits

Dry eye disease (DED) has become common on a global scale in recent years. There is a wide prevalence of DED in different countries based on various ethnicities and environment. DED is a multifactorial ocular disorder. In addition to advanced age and gender, such factors as living at high altitude, smoking, pterygium, prolonged use of consumer electronics or overingesting of caffeine or multivitamins are considered to be the major risk factors of DED. We report the DED epidemiology in Taiwan firstly in this article. According to the pathophysiological factors and changes inthe composition of the tear film in DED, it can be categorized into several subtypes, including lipid anomaly dry eye, aqueous tear deficiency, allergic and toxic dry eye among others. Each subtype has its own cause and disease management; therefore, it is important for ophthalmologists to identify the type through literature review and investigation. The management of DED, relies not only on traditional medications such as artificial tears, gels and ointments, but also newer treatment options such as acupuncture, SYL1001, and nanomedicine therapy. We also conducted a comprehensive literature review including common subtypes and treatment of DED. Clearly, more clinical trials are needed to assess the efficacy and safety of the various treatments and common subtypes of DED.

Colonic delivery of indometacin loaded PGA-co-PDL microparticles coated with Eudragit L100-55 from fast disintegrating tablets

The aim of this work was to investigate the efficient targeting and delivery of indometacin (IND), as a model anti-inflammatory drug to the colon for treatment of inflammatory bowel disease. We prepared fast disintegrating tablets (FDT) containing IND encapsulated within poly(glycerol-adipate-co-ɷ-pentadecalactone), PGA-co-PDL, microparticles and coated with Eudragit L100-55 at different ratios (1:1.5, 1:1, 1:0.5). Microparticles encapsulated with IND were prepared using an o/w single emulsion solvent evaporation technique and coated with Eudragit L-100-55 via spray drying. The produced coated microparticles (PGA-co-PDL-IND/Eudragit) were formulated into optimised FTD using a single station press. The loading, in vitro release, permeability and transport of IND from PGA-co-PDL-IND/Eudragit microparticles was studied in Caco-2 cell lines. IND was efficiently encapsulated (570.15±4.2μg/mg) within the PGA-co-PDL microparticles. In vitro release of PGA-co-PDL-IND/Eudragit microparticles (1:1.5) showed significantly (p<0.05, ANOVA/Tukey) lower release of IND 13.70±1.6 and 56.46±3.8% compared with 1:1 (89.61±2.5, 80.13±2.6%) and 1:0.5 (39.46±0.9 & 43.38±3.12) after 3 and 43h at pH 5.5 and 6.8, respectively. The permeability and transport studies indicated IND released from PGA-co-PDL-IND/Eudragit microparticles had a lower permeability coefficient of 13.95±0.68×10^-6cm/s compared to free IND 23.06±3.56×10^-6cm/s. These results indicate the possibility of targeting anti-inflammatory drugs to the colon using FDTs containing microparticles coated with Eudragit.

A Comprehensive Review on Dry Eye Disease: Diagnosis, Medical Management, Recent Developments, and Future Challenges

Dry eye syndrome (DES) or keratoconjunctivitis sicca (KCS) is a common disorder of the tear film caused by decreased tear production or increased evaporation and manifests with a wide variety of signs and symptoms. The present review from interpretation of the literature gives detailed information on the prevalence, definition, causes, diagnostic tests, and medical management of dry eye disease. A number of systems contribute to the physiological integrity of the ocular surface and disruption of system may or may not produce symptoms. Therefore accurate diagnosis of dry eyes with no or minimal disruption of physiological function is necessary. The paper also discusses different colloidal drug delivery systems and current challenges in the development of topical ophthalmic drug delivery systems for treatment of KCS. Due to the wide prevalence and number of factors involved, newer, more sensitive diagnostic techniques and novel therapeutic agents have been developed to provide ocular delivery systems with high therapeutic efficacy. The aim of this review is to provide awareness among the patients, health care professionals, and researchers about diagnosis and treatment of KCS and recent developments and future challenges in management of dry eye disease.