A study of refractory cases of persistent epithelial defects associated with dry eye syndrome and recurrent corneal erosions successfully treated with cyclosporine A 0.05% eye drops

Cyclosporine a Eluting Nano Drug Reservoir Film for the Management of Dry Eye Disease

Cyclosporine A (CsA) is widely used to treat dry eye disease (DED), and ocular morbidity is on the rise and is a growing concern globally. However, several drug and formulation challenges, such as poor drug solubility, short pre-corneal residence time, and poor patient compliance, have limited the ocular bioavailability of CsA to < 5%. A CsA cyclodextrin-based ternary complex loaded dissolvable nano drug reservoir films were developed to overcome these limitations and efficiently manage DED. Drug-loaded nano-reservoir films were fabricated via lithography using silicone and poly (dimethyl siloxane) (PDMS) molds. Different physicochemical characterizations were performed to confirm the formation of stable CsA-cyclodextrin-based ternary complexes. Formation of nanoreservoirs on the films was confirmed using SEM and AFM. Optimized CsA-complex-loaded nano-reservoir films were evaluated for in vitro drug release, ex vivo corneal permeation, and in vivo precorneal retention. Preclinical efficacy studies were performed to assess the efficacy of CsA-complex-loaded nano-reservoirs in an experimental dry-eye mouse model. Physicochemical characterization confirmed the formation of a stable complex and the improved solubility of CsA. In vitro release and ex vivo permeation studies indicated a controlled drug release and improved permeation, respectively. Furthermore, tear volume measurement and corneal damage assessment using slit-lamp imaging suggested decreased dry eye symptoms, significantly increasing tear volume in the drug-loaded nano-reservoir-treated group. Moreover, histopathological studies corroborated the tear volume and slit-lamp imaging results, with reduced inflammation and neovascularization. The poorly water-soluble drug with cyclodextrin complex incorporated nanoreservoir films presents a potential alternative for managing various ocular diseases.

Effects of cyclosporine on steroid-refractory dry eyes

PURPOSE

The purpose is to compare the effects of cyclosporine (CsA) on the steroid-refractory mixed-type dry eye (MTDE) and aqueous deficient dry eye (ADDE).

MATERIALS AND METHODS

We retrospectively enrolled 71 patients with levels 3 and 4 dry eye that were refractory to artificial tears and topical steroids. The effects were analyzed using the ocular surface disease index (OSDI) and standard patient evaluation of eye dryness (SPEED) questionnaires, Schirmer test II, blink patterns, lipid layer thickness (LLT), meibomian gland expressibility (MGE) and extent of meibomian gland (MG) dropout (meiboscale).

RESULTS

MTDE patients (LLT ≤60 nm, n = 38) were younger than those in ADDE (LLT >60 nm, n = 33). Before CsA treatment, they had higher Schirmer scores, less MGE, and a thinner LLT. There was no statistically significant difference in OSDI/SPEED scores between groups. CsA improved the OSDI in the ADDE group but not in the MTDE group. CsA treatment decreased the severity of superficial punctate keratitis (SPK) in both groups, but it significantly decreased partial blinks, total blinks, and partial blink rates in the ADDE group only. CsA did not increase the Schirmer score, LLT, MGE, or meiboscale grade in both groups. CsA could significantly improve subjective symptoms, SPK, and blink patterns in dry eyes refractory to topical steroids, which were more pronounced in ADDE than in MTDE.

CONCLUSION

In MTDE cases, concurrent MG treatment modalities, such as intense pulse light and/or thermal pulsation, could be considered to maximize the effects of CsA treatment.

Recurrent corneal erosion

Recurrent corneal erosion (RCE) is a common recurrent disease caused by abnormal adhesion of the corneal epithelium to the basement membrane. Previous corneal trauma is the most common cause of this disease. Corneal dystrophies, such as dystrophy of the epithelial basement membrane, Meesmann dystrophy, ReisBcklers dystrophy, lattice dystrophy and granular dystrophies, are also involved in the pathogenesis of recurrent corneal erosion. The main diagnostic methods for recurrent corneal erosion are slit-lamp examination and taking of medical history. Detectable RCE changes range from small corneal irregularities (such as epithelial microcysts) to large areas of loose epithelium or epithelial defects detecting by fluorescein staining. Areas of irregular epithelium with grayish inclusions or microcysts and a fingerprint pattern or a map-like defects are also revealed. The main goal of treatment is to relieve pain, stimulate re-epithelialization, and fully restore the adhesion of the basement membrane and epithelium. Lubricants and matrix proteinase inhibitors are prescribed as first-line therapy, and blood derivatives can be used as second-line therapy. When conservative therapy fails, surgical procedures are used (excimer laser phototherapeutic keratectomy, Bowmans membrane polishing with diamond drill, anterior stromal puncture, corneal collagen cross-linking).

Isorhamnetin Ameliorates Dry Eye Disease via CFTR Activation in Mice

Dry eye disease is one of the most common diseases, with increasing prevalence in many countries, but treatment options are limited. Cystic fibrosis transmembrane conductance regulator (CFTR) is a major ion channel that facilitates fluid secretion in ocular surface epithelium and is a potential target of therapeutic agent for the treatment of dry eye disease. In this study, we performed a cell-based, high-throughput screening for the identification of novel natural products that activate CFTR and restore the aqueous deficiency in dry eye. Screening of 1000 natural products revealed isorhamnetin, a flavonol aglycone, as a novel CFTR activator. Electrophysiological studies showed that isorhamnetin significantly increased CFTR chloride current, both wild type and ∆F508-CFTR. Isorhamnetin did not alter intracellular cAMP levels and the activity of other ion channels, including ANO1, ENaC, and hERG. Notably, application of isorhamnetin on mouse ocular surface induced CFTR activation and increased tear volume. In addition, isorhamnetin significantly reduced ocular surface damage and expression of interleukin (IL)-1β, IL-8, and tumor necrosis factor (TNF)-α in an experimental mouse model of dry eye. These data suggest that isorhamnetin may be used to treat dry eye disease.

A Review of the Mechanism of Action of Cyclosporine A: The Role of Cyclosporine A in Dry Eye Disease and Recent Formulation Developments

Dry eye disease (DED) is a multifactorial disease of the ocular surface and tear film that has gained awareness as a public health problem. Characteristics of DED include tear film instability, hyperosmolarity, and ocular surface inflammation, which can occur independently or may be a sequela of numerous ocular diseases, ocular surgery or contact lens wear. Much has been learned about the impact of the disease to help affected individuals who report symptoms of poor vision, pain, and tearing. Recently, new research highlights the importance of the role of ocular surface inflammation and damage in DED-leading to a vicious cycle of inflammation as well as loss of tear film homeostasis. DED immunopathophysiology is characterized by four stages: initiation, amplification, recruitment, and re-initiation. Cyclosporine is proven to be a valuable ophthalmic therapeutic for DED through its immunomodulatory actions and regulation of the adaptive immune response. Cyclosporine mechanism of action is well described in the published literature and the myriad of benefits in all four stages lend a broad-based immunomodulatory function particularly suitable for addressing DED. Furthermore, cyclosporine has unique goblet cell density improvement capabilities as well as anti-apoptotic properties. Topical formulations of cyclosporine are centered around addressing the highly lipophilic nature of the molecule. The poor aqueous solubility of cyclosporine traditionally presented technical challenges in drug delivery to the ocular surface. Newer formulations such as cationic emulsions and nanomicellar aqueous solutions address formulation, tissue concentration, and drug delivery challenges.