Topical tacrolimus in anterior segment inflammatory disorders

Treatment of Dry Eye Disease (DED) in Asia: Strategies for Short Tear Film Breakup Time-Type DED

Dry eye disease (DED) is a multifactorial disorder in which tear fluid homeostasis is lost, resulting in increased tear film osmolarity and ocular surface irritation. In Asia, the short tear film breakup time-type DED, which has become a global problem in recent years, is common. While the mainstay of DED treatment in the West is the suppression of inflammation, the first goal of treatment is the stabilization of the tear film in Asia. To date, artificial tears and steroid eye drops have been the main treatment for DED. However, artificial tears require frequent administration of eye drops and thus pose adherence problems, while steroids have problems with side-effects (cataracts, increased intraocular pressure). This review evaluates the new generation therapies in Asia based on what is known about them and demonstrates that they are more effective for DED than traditional therapies such as artificial tears and steroids. Based on considerations, it is proposed that the optimal treatment for the short tear film breakup time-type DED is the initial application of mucin-secretion-enhancing eye drops (long-acting diquafosol) and oral supplements; and if additional treatment is needed, cyclosporine eye drops and the adjunctive therapies presented in this review are added.

The Role of Sensory Innervation in Homeostatic and Injury-Induced Corneal Epithelial Renewal

The cornea is the window through which we see the world. Corneal clarity is required for vision, and blindness occurs when the cornea becomes opaque. The cornea is covered by unique transparent epithelial cells that serve as an outermost cellular barrier bordering between the cornea and the external environment. Corneal sensory nerves protect the cornea from injury by triggering tearing and blink reflexes, and are also thought to regulate corneal epithelial renewal via unknown mechanism(s). When protective corneal sensory innervation is absent due to infection, trauma, intracranial tumors, surgery, or congenital causes, permanent blindness results from repetitive epithelial microtraumas and failure to heal. The condition is termed neurotrophic keratopathy (NK), with an incidence of 5:10,000 people worldwide. In this report, we review the currently available therapeutic solutions for NK and discuss the progress in our understanding of how the sensory nerves induce corneal epithelial renewal.

Role of topical and systemic immunosuppression in aqueous-deficient dry eye disease

Immunosuppression in aqueous-deficient dry eye disease (ADDE) is required not only to improve the symptoms and signs but also to prevent further progression of the disease and its sight-threatening sequelae. This immunomodulation can be achieved through topical and/or systemic medications, and the choice of one drug over the other is determined by the underlying systemic disease. These immunosuppressive agents require a minimum of 6-8 weeks to achieve their beneficial effect, and during this time, the patient is usually placed on topical corticosteroids. Antimetabolites such as methotrexate, azathioprine, and mycophenolate mofetil, along with calcineurin inhibitors, are commonly used as first-line medications. The latter have a pivotal role in immunomodulation since T cells contribute significantly to the pathogenesis of ocular surface inflammation in dry eye disease. Alkylating agents are largely limited to controlling acute exacerbations with pulse doses of cyclophosphamide. Biologic agents, such as rituximab, are particularly useful in patients with refractory disease. Each group of drugs has its own side-effect profiles and requires a stringent monitoring schedule that must be followed to prevent systemic morbidity. A customized combination of topical and systemic medications is usually required to achieve adequate control, and this review aims to help the clinician choose the most appropriate modality and monitoring regimen for a given case of ADDE.

Management of Vernal Keratoconjunctivitis in Children in the United Kingdom: A Review of the Literature and Current Best Practice Across Six Large United Kingdom Centers

Vernal keratoconjunctivitis (VKC) is a form of ocular allergy primarily affecting children. Considered a rare disease in Europe, its prevalence varies by geographic region and is poorly studied in the United Kingdom. There is considerable national variation in the management of VKC within the United Kingdom, risking misdiagnosis and delays to treatment for some children. This can significantly impact their quality of life, with the potential for lasting negative consequences. Based on discussions between experienced clinicians from six large centers across the United Kingdom, this article describes best practice recommendations for United Kingdom settings, including principles for diagnosis, referral, initial and long-term management, and supportive care. Recommendations include guidance on referral timing, which should depend on VKC severity, and a stepwise approach to treatment. Joint management by primary care and secondary care is recommended and the importance of supportive care, including emotional support and outreach to schools, is highlighted. Because frequent flareups are common in VKC, it is essential that families have access to the information they need to manage the disease and routes to access rapid care if needed. A thorough understanding of the nature of VKC, its triggers, and how best to manage it, by both patients and their families, is critical to ensuring appropriate management and to improving patient outcomes. [J Pediatr Ophthalmol Strabismus. 2023;60(1):6-17.].

Comparison of topical 0.03% tacrolimus and homologous injectable platelet-rich plasma in the treatment of keratoconjunctivitis sicca in dogs

Background and Aim

Keratoconjunctivitis sicca (KCS) is predominantly an immune-mediated chronic inflammatory ocular disease that is commonly diagnosed in dogs. This study aimed to compare the conventional use of topical immunosuppressant tacrolimus 0.03% eye drops and a new therapy injectable homologous platelet-rich plasma (HPRP) into the third eyelid gland and inferior and superior palpebral conjunctiva of dogs with KCS.

Materials and Methods

A total of 66 eyes from 33 dogs were evaluated. The eyes were divided into three equal groups: Negative control group, tacrolimus group (TG), and homologous platelet-rich plasma group (HPRPG). The animals were evaluated using the Schirmer's tear test-1 (STT-1), osmolarity test (OT), strip meniscometry test (SMT), tear film break-up test (TBUT), fluorescein test, lissamine green test (LGT), and cytological and histopathological analyses.

Results

In TG, there was a significant increase (p < 0.05) in the STT-1 and SMT values, and goblet cell count in the palpebral conjunctiva by the end of the study. In HPRPG, 36% (four dogs) received three applications, 55% (six dogs) received two applications, and 9% (one dog) received one application before the initial ocular signs improved. There was a significant decrease (p < 0.05) in the lymphocyte and neutrophil counts of the palpebral conjunctiva in HPRPG than in TG. Both groups showed equivalent improvements in TBUT, OT, and LGT values.

Conclusion

Tacrolimus 0.03% eye drops were more efficient than HPRP in increasing tear production and the number of goblet cells. However, injectable HPRP was more efficient than tacrolimus in decreasing the number of conjunctival inflammatory cells. Treatment with injectable HPRP requires an average of two to three applications, is safe and feasible, and can be used as a cheaper alternative or as an adjuvant to conventional treatment with topical immunosuppressants.

Sustained Release of Tacrolimus From a Topical Drug Delivery System Promotes Corneal Reinnervation

Purpose

Corneal nerve fibers provide sensation and maintain the epithelial renewal process. Insufficient corneal innervation can cause neurotrophic keratopathy. Here, topically delivered tacrolimus is evaluated for its therapeutic potential to promote corneal reinnervation in rats.

Methods

A compartmentalized neuronal cell culture was used to determine the effect of locally delivered tacrolimus on sensory axon regeneration in vitro. The regenerating axons but not the cell bodies were exposed to tacrolimus (50 ng/mL), nerve growth factor (50 ng/mL), or a vehicle control. Axon area and length were measured after 48 hours. Then, a biodegradable nanofiber drug delivery system was fabricated via electrospinning of a tacrolimus-loaded polycarbonate–urethane polymer. Biocompatibility, degradation, drug biodistribution, and therapeutic effectiveness were tested in a rat model of neurotrophic keratopathy induced by stereotactic trigeminal nerve ablation.

Results

Sensory neurons whose axons were exposed to tacrolimus regenerated significantly more and longer axons compared to vehicle-treated cultures. Trigeminal nerve ablation in rats reliably induced corneal denervation. Four weeks after denervation, rats that had received tacrolimus topically showed similar limbal innervation but a significantly higher nerve fiber density in the center of the cornea compared to the non-treated control. Topically applied tacrolimus was detectable in the ipsilateral vitreal body, the plasma, and the ipsilateral trigeminal ganglion but not in their contralateral counterparts and vital organs after 4 weeks of topical release.

Conclusions

Locally delivered tacrolimus promotes axonal regeneration in vitro and corneal reinnervation in vivo with minimal systemic drug exposure.

Translational Relevance

Topically applied tacrolimus may provide a readily translatable approach to promote corneal reinnervation.

A Case of Tacrolimus Maculopathy

(1) Background: Tacrolimus is an immunosuppressive agent commonly used in the management of solid organ allogeneic transplants in the prevention of rejection. Serious ophthalmic adverse effects with Tacrolimus have been reported in the literature, which includes cortical blindness and optic neuropathy. (2) Methods: We describe a rare case of maculopathy as a possible complication of Tacrolimus therapy. A 56-year-old man receiving Tacrolimus for immunosuppression after liver transplantation developed unilateral visual disturbance with a central scotoma. (3) Results: Ophthalmologic examination revealed unilateral maculopathy; a Tacrolimus macular toxicity was suspected. After drug discontinuation, a complete visual recovery was observed; however, the ultrastructural macular damage was irreversible. (4) Conclusions: Reports regarding maculopathy associated with Tacrolimus are limited. This case report adds to the current literature regarding the possible macular toxicity of this immunosuppressive agent, especially if it exceeds therapeutic serum levels. Further data are needed to confirm this possible association. A careful ophthalmologic examination should be promptly performed in patients manifesting visual disturbance while taking Tacrolimus to prevent irreversible, permanent vision loss due to possible drug toxicity.

Use of Topical Cyclosporin and Tacrolimus for Recurrent Subepithelial Infiltrates after Epidemic Keratoconjunctivitis

Purpose: To report a case of recurrent subepithelial infiltrates (SEIs) after epidemic keratoconjunctivitis (EKC), which improved with the use of topical cyclosporin and tacrolimus.Case summary: A 33‐year‐old female patient with bilateral EKC developed multiple SEIs, which were worse in the left eye, after applying topical antibiotics and steroid for 3 weeks. She was administered 0.5% loteprednol etabonate every 2 hours, which was gradually tapered to once a day, and 0.1% cyclosporine once daily. However, the SEIs recurred. Therefore, 0.1% cyclosporine was administered twice a day in both eyes and the frequency of administration of steroid eye drops was increased. The dose of steroid eye drops was reduced, but two attempts to taper the dose failed. SEIs in the right eye improved with the use of 0.1% cyclosporine. However, SEIs in the left eye recurred on tapering the steroid dose. Therefore, topical 0.02% tacrolimus ointment was administered once daily in the left eye. After 2 weeks of using tacrolimus, the topical steroids were discontinued. SEIs were well‐controlled for 6 months with 0.1% cyclosporine administered 1‐2 times/day in the right eye and 0.02% tacrolimus administered 1 time/3 days in the left eye.Conclusions: Topical cyclosporine and tacrolimus can minimize the requirement for steroids, and treat chronic and recurrent SEIs after EKC.

Characterization and In Vitro and In Vivo Evaluation of Tacrolimus-Loaded Poly(ε-Caprolactone) Nanocapsules for the Management of Atopic Dermatitis

BACKGROUND

Tacrolimus (TAC) is a drug of natural origin used in conventional topical dosage forms to control atopic dermatitis. However, direct application of the drug often causes adverse side effects in some patients. Hence, drug nanoencapsulation could be used as an improved novel therapy to mitigate the adverse effects and enhance bioavailability of the drug.

METHODS

Physicochemical properties, in vitro drug release experiments, and in vivo anti-inflammatory activity studies were performed.

RESULTS

TAC-loaded nanocapsules were successfully prepared by the interfacial deposition of preformed polymer using poly(ε-caprolactone) (PCL). The nanoparticulate systems presented a spherical shape with a smooth and regular surface, adequate diameter (226 to 250 nm), polydispersity index below 0.3, and suitable electrical stability (-38 to -42 mV). X-ray diffraction confirmed that the encapsulation method provided mainly the drug molecular dispersion in the nanocapsule oily core. Fourier-transform infrared spectra suggested that nanoencapsulation did not result in chemical bonds between drug and polymer. In vitro drug dissolution experiments showed a controlled release with a slight initial burst. The release kinetics showed zero-order kinetics. As per the Korsmeyer-Peppas model, anomalous transport features were observed. TAC-loaded PCL nanocapsules exhibited excellent anti-inflammatory activity when compared to the free drug.

CONCLUSIONS

TAC-loaded PCL nanocapsules can be suitably used as a novel nano-based dosage form to control atopic dermatitis.

Development of Cytomegalovirus Corneal Endotheliitis During Long-Term Topical Tacrolimus and Steroid Treatment for Chronic Ocular Surface Inflammatory Diseases

PURPOSE

We report 3 cases of patients with chronic ocular surface inflammatory disease who developed cytomegalovirus (CMV) corneal endotheliitis during immunosuppressant and steroid treatment.

PATIENTS AND METHODS

This is a retrospective observational study analyzing the clinical characteristics and outcomes of 3 patients with ocular surface inflammatory diseases (2 with Mooren ulcer and 1 with idiopathic scleritis) who developed CMV corneal endotheliitis. All patients developed CMV corneal endotheliitis between 8 and 14 months of starting steroid and immunosuppressant treatment, including topical 0.1% tacrolimus. Decimal visual acuity, endothelial counts, and intraocular pressure were analyzed.

RESULTS

All patients received topical 0.5% ganciclovir after the diagnosis of CMV corneal endotheliitis, which improved endothelial inflammation. However, all patients developed irreversible mydriasis and required additional surgeries, including endothelial keratoplasty, cataract surgery, and glaucoma surgery. At the final follow-up (14-46 months post-CMV corneal endotheliitis onset), fair outcomes were achieved, as demonstrated by a mean decimal best-corrected visual acuity of 0.3 and a well-controlled intraocular pressure.

CONCLUSIONS

Topical steroids and immunosuppressants can induce fulminant CMV corneal endotheliitis with cataract progression and irreversible mydriasis. In these cases, early diagnosis and treatment, including topical 0.5% ganciclovir, glaucoma surgery, cataract surgery, and endothelial keratoplasty, are necessary for preserving the patient's vision.

Topical Tacrolimus Progylcosomes Nano-Vesicles As a Potential Therapy for Experimental Dry Eye Syndrome

The present work aimed to evaluate the efficacy of topical tacrolimus (0.01%) loaded propylene glycol (PG) modified nano-vesicles (Proglycosomes Nano-vesicles, PNVs) for the treatment of experimental dry eye syndrome (DES) in rabbits. DES was induced by topical application of atropine (1.0%) and benzalkonium chloride (0.1%) aqueous solution. PNVs treatment (PNV group) was compared with tacrolimus solution 0.01% (TAC group) and untreated group and healthy group were used as controls. PNV treated animals showed improved clinical performance with marked increase in tear production and tear break-up time (TBUT). Further, PNVs also subside ocular inflammation as evident from absence of matrix metalloprotenaise-9 and normal ocular surface temperature (32.3 ± 0.34 °C). Additionally, PNVs have positive effect on ocular and epithelial damage observed through low ocular surface staining score and improved globlet cell density. The PNV treatment was found to more effectively compared to TAC solution and most of the parameters were close to those of healthy animals. In conclusion, tacrolimus PNV formulation (0.01%) could be a potential therapy for treatment of dry eye syndrome.

Syphilitic interstitial keratitis treated with topical tacrolimus

Purpose

To report a case of syphilitic interstitial keratitis successfully managed with topical tacrolimus after the development of steroid-induced intraocular pressure elevation in a pediatric patient.

Observations

A 4-year-old female with a history of congenital syphilis that was reportedly treated after birth presented with bilateral conjunctival redness, tearing, and photosensitivity. Initial ophthalmic examination revealed corneal vascularization with diffuse haze of the right eye and circumferential vascularization with stromal infiltrates of the left eye. She was diagnosed with bilateral syphilitic interstitial keratitis and initially managed with topical steroids but developed steroid-induced elevation of her intraocular pressure. She experienced several recurrences of keratitis as steroids were tapered. After a recurrence in her right eye, she was treated with topical tacrolimus. Since then, she has remained recurrence-free for almost three years with normal intraocular pressure.

Conclusion and importance

Tacrolimus represents a novel alternative for the treatment of syphilitic interstitial keratitis, which is particularly useful in patients that develop elevated intraocular pressures in response to long-term treatment with steroid eye drops.

Long-term results of topical 0.02% tacrolimus ointment for refractory ocular surface inflammation in pediatric patients

BACKGROUND

No studies have been reported on the efficacy and safety of long-term (≥12 months) use of topical tacrolimus for refractory ocular surface inflammation in pediatric patients.

METHODS

Medical records of pediatric patients who were prescribed topical 0.02% tacrolimus ointment for refractory ocular surface inflammation between January of 2010 and March of 2018 were reviewed retrospectively. Changes in ocular surface signs during slit-lamp examination, clinical symptoms and concurrent steroid use were graded with a scoring system. The presence of side effects was also assessed. The changes in disease severity and patient symptoms were compared between baseline and after the treatment.

RESULTS

Among 72 patients (55% males, mean age 10.8 ± 3.9 years, range 3 to 17 years), 25 patients (48% males, mean age 11.4 ± 3.9 years) fully recovered, resulting in discontinuance of the ointment treatment before 12 months. Six patients experienced intolerable burning sensation, which required treatment cessation. Cessation days of those who quit were 1,5,14,20,26, and 35 days. Seven patients were lost during follow-up. Thirty-four patients (56% males, mean age 11.2 ± 4.2 years, range 3 to 17 years) were treated with tacrolimus ointment for over 12 months (average 23.1 ± 19.1 months, range 12 to 98 months). During the follow-up period, all patients showed improved clinical signs and symptoms, and no adverse reaction was noted.

CONCLUSIONS

Long-term maintenance of topical tacrolimus 0.02% ointment is safe and effective in improving refractory ocular surface inflammation in pediatric patients.

Vernal keratoconjunctivitis: An update

Vernal keratoconjunctivitis (VKC) and atopic keratoconjunctivitis (AKC) are potentially severe and complex disease in its management among the various allergic eye diseases. In this regard, studies clarified the etiopathogenetic mechanisms. The workup should be multidisciplinary. The treatment includes topical and systemic medications with anti-inflammatory and immunosuppressant activity. However, a definition of nationally- and internationally-shared diagnostic protocols would also be needed and validated access to therapeutic options of proven safety and efficacy to avoid the use of galenic preparations, up to now still essential in the management of moderate-severe VKC. Finally, recognizing VKC and AKC, among rare diseases, at a national and international level would be an essential step to allow the management of VKC with adequate timings and settings within the National Health System.

Topical tacrolimus nanocapsules eye drops for therapeutic effect enhancement in both anterior and posterior ocular inflammation models

Tacrolimus has shown efficacy in eye inflammatory diseases. However, due to the drug lability, its formulation into a stable ophthalmic product remains a challenge. Tacrolimus-loaded nanocapsules (NCs) were designed for ocular instillation. Further, the stability and effects of the formulation were analyzed under different experimental conditions. Physicochemical characterization of the NCs revealed suitable homogeneous size and high encapsulation efficiency. Moreover, the lyophilized formulation was stable at ICH long term and accelerated storage conditions, for at least 18 and 3 months, respectively. The tacrolimus NCs did not elicit any eye irritation in rabbits after single- and multiple-dose applications. Additionally, ex vivo penetration assays on isolated porcine cornea and pharmacokinetics analyses in various rabbit eye compartments demonstrated the superiority of the NCs in retention and permeation into the anterior chamber of the eye compared to the free drug dissolved in oil. Moreover, multiple dose ocular instillation of the NCs in rats allowed high tacrolimus levels in the eye with very low plasma concentrations. Finally, the developed delivery system achieved a significant decrease in four typical inflammatory markers in a murine model of keratitis, an anterior chamber inflammation. Furthermore, these NCs, applied as eye drops, displayed clinical and histological efficacy in the mainly posterior chamber inflammation model of murine, experimental auto-immune uveitis.

Topical Tacrolimus in Thygeson Superficial Punctate Keratitis

PURPOSE

To evaluate the efficacy of topical tacrolimus 0.02% eye drops in the treatment of patients with Thygeson superficial punctate keratitis.

METHODS

Ten consecutive patients with Thygeson superficial punctate keratitis were included retrospectively. Seven patients were unresponsive to topical steroids and/or lubricants. Diagnosis was made based on the history and clinical findings. All patients were treated with topical tacrolimus 0.02% solution twice daily. Outcome measures included improvement in symptoms of tearing and photophobia, whereas improvement in signs included decrease in the number of the lesions, resolution of the lesions, flattening of the lesions, and decrease in stain of the lesions.

RESULTS

There were 3 male and 7 female patients with an age range of 3 to 51 years (mean 17 years). All patients had bilateral ocular involvement. Duration of treatment ranged from 1 to 42 weeks (mean 10 weeks). All patients had subjective improvement in symptoms of tearing and photophobia and resolution of the superficial punctate keratitis. The response to treatment was noted 72 hours after initiation of therapy in all patients. Topical tacrolimus was well tolerated in all patients.

CONCLUSIONS

Topical tacrolimus 0.02% is safe and effective in reducing ocular surface inflammation in patients with Thygeson superficial punctate keratitis who are not responsive to conventional therapy. Tacrolimus is helpful as a steroid-sparing agent to avoid vision-threatening complications.

Comparison of therapeutic effects between topical 8-oxo-2'-deoxyguanosine and corticosteroid in ocular alkali burn model

We compared the therapeutic effects of topical 8-oxo-2'-deoxyguanosine (8-oxo-dG) and corticosteroid in a murine ocular alkali burn model. (n = 128) The corneal alkali burn model was established by applying 0.1 N sodium hydroxide (NaOH), followed by treatment with 8-oxo-dG, 0.1% fluorometholone (FML), 1% prednisolone acetate (PDE), or phosphate-buffered saline (PBS) twice daily. One week later, the clinical and histological status of the cornea were assessed. Transcript levels of inflammatory cytokines and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase as well as the levels of reactive oxygen species (ROS) and reactive nitrogen species (RNS) in the cornea, were assayed. The 8-oxo-dG and PDE groups showed marked improvements in corneal integrity and clarity when compared with the PBS group (each p < 0.01). The numbers of cells stained for neutrophil elastase and F4/80-positive inflammatory cells were significantly decreased, with levels of interleukin(IL)-1β, IL-6, tumor necrosis factor(TNF)-α, and total ROS/RNS amounts markedly reduced in the 8-oxo-dG, FML, and PDE groups (each p < 0.05). Levels of NADPH oxidase type 2 and 4 were substantially more repressed in the 8-oxo-dG-treated group than in the PDE-treated group (each p < 0.05). Topical 8-oxo-dG showed excellent therapeutic effects that were comparable with those treated with topical PDE in a murine ocular alkali burn model.

Long-term outcomes of 0.1% tacrolimus eye drops in eyes with severe allergic conjunctival diseases

Background

Because atopic dermatitis does not heal completely, associated severe atopic keratoconjunctivitis (AKC) and vernal keratoconjunctivitis (VKC) often require long-term treatment. This study aims to evaluate the long-term outcomes of using 0.1% tacrolimus eye drops to treat these severe allergic conjunctival diseases.

Methods

Two-hundred-and-seventy eyes of 135 patients diagnosed with AKC or VKC from April 2004 to April 2014 were screened retrospectively. Patient demographics and objective signs were extracted from the electronic medical records. The severity of 10 objective signs, related to the palpebral and bulbar conjunctiva, limbus, and cornea, and intraocular pressure (IOP) were observed at baseline, at 2 weeks, 1, 2, 3, 6, and 12 months after starting treatment, and every 1 year thereafter (average use period: 8.4 ± 2.9 years). Safety was evaluated based on the incidence and severity of adverse events.

Results

12 patients (AKC; 7 cases, VKC; 5 cases) who were treated with 0.1% tacrolimus eye drops were enrolled in this study. The total score of clinical signs significantly decreased after 2 weeks and remained effective thereafter. Tacrolimus eye drops elicited a statistically significant difference in the mean total clinical scores and IOP over the course of treatment (P < 0.001). Elevated IOP was observed in 2 cases and corneal infection in 1 case; these effects were completely controlled with medication.

Conclusions

Topical tacrolimus may provide effective and long-term improvement in clinical signs of severe AKC and VKC cases that refractory to standard conventional treatment.

Trial registration: University Hospital Medical Information Network (UMIN) 000034460.

Surface functionalized mesoporous silica nanoparticles for intravitreal application of tacrolimus

Tacrolimus (TAC), a potent immunosuppressive macrolide, has been investigated for ocular diseases due to promising results in the treatment of anterior and posterior segments eye diseases. Mesoporous and functionalized silica nanoparticles show potential as TAC delivery platforms owing to their interesting characteristic as large surface area, uniform pore size distribution, high pore volume, and excellent biocompatibility. The purpose of this study was to incorporate TAC in functionalized silica nanoparticles with 3-aminopropyltriethoxysilane (MSNAPTES) and investigate the safety and biocompatibility of the systems. The MSNAPTES and MSNAPTES TAC nanoparticles were characterized. The in vitro cytotoxicity of MSNAPTES and MSNAPTES load with TAC (MSNAPTES-TAC) in retinal pigment epithelial cells (ARPE-19) was determined, chorioallantoic membrane (CAM) assay model was used to investigate the in vivo biocompatibility, and safety of intravitreal injection was evaluated using clinical examination (assessment of intraocular pressure and indirect fundus ophthalmoscopy), electroretinographic (ERG) and histologic studies in rats' eyes. The elemental analysis (CHN), thermogravimetric (TGA), photon correlation spectroscopy and Fourier transform infrared (FTIR) analysis confirmed the presence of functionalized agent and TAC in the MSNAPTES nanoparticles. TAC loading was estimated at 7% for the MSNAPTES TAC nanoparticles. MSNAPTES and MSNAPTES TAC did not present in vitro cytotoxicity. The drug delivery systems showed good biocompatibility on CAM. No retinal abnormalities, vitreous hemorrhage, neovascularization, retinal detachment, and optic nerve atrophy were observed during the in vivo study. Follow-up ERGs showed no changes in the function of the retina cells after 15 days of intravitreal injection, and histopathologic observations support these findings. In conclusion, MSNAPTES TAC was successfully synthesized, and physicochemical analyses confirmed the presence of TAC in the nanoparticles. In vitro and in vivo studies indicated that MSNAPTES TAC was safe to intravitreal administration. Taking into account the enormous potential of MSNAPTES to carry TAC, this platform could be a promising strategy for TAC ocular drug delivery in the treatment of eye diseases.

Amelioration of Endotoxin-Induced Uveitis in Rabbit by Topical Administration of Tacrolimus Proglycosome Nano-Vesicles

This work was aimed to improve the efficacy of tacrolimus in the treatment of endotoxin-induced uveitis (EIU) using propylene glycol modified lipid vesicles termed as proglycosome nano-vesicles (PNVs). PNVs were prepared by modified film hydration method. Experimental uveitis in rabbit eye was induced by an intravitreal injection of 20 μL of the endotoxin solution containing 100 ng of lipopolysaccharide endotoxin. In vivo efficacy of PNVs was determined by studying clinical symptoms of uveitis using slit lamp examination and by quantitatively measuring levels of tumor necrosis factor-alpha, interleukin-6, leukocytes and total proteins in aqueous humor, 24 h after intravitreal injection of endotoxin. Comparison was made with healthy, untreated and tacrolimus solution treated eyes. PNVs developed were nano-sized, deformable and showed sustained release of tacrolimus over period of 12 h. In vivo results indicated statistically significant difference between the effects of PNVs in the treatment of EIU compared to tacrolimus. PNV treatment not only subsides clinical symptoms of uveitis but also prevented breakdown of blood aqueous barrier. Tacrolimus loaded PNVs are potential new topical treatment for uveitis.

Nanotechnology for the Treatment of Allergic Conjunctival Diseases

Allergic conjunctivitis is one of the most common external eye diseases and the prevalence has been increasing. The mainstay of treatment is topical eye drops. However, low bioavailability, low ocular drug penetration, transient resident time on the ocular surface due to tear turnover, frequent topical applications and dependence on patient compliance, are the main drawbacks associated with topical administration. Nanotechnology-based medicine has emerged to circumvent these limitations, by encapsulating the drugs and preventing them from degradation and therefore providing sustained and controlled release. Using a nanotechnology-based approach to load the drug is particularly useful for the delivery of hydrophobic drugs such as immunomodulatory agents, which are commonly used in allergic conjunctival diseases. In this review, different nanotechnology-based drug delivery systems, including nanoemulsions, liposomes, nanomicelles, nanosuspension, polymeric and lipid nanoparticles, and their potential ophthalmic applications, as well as advantages and disadvantages, are discussed. We also summarize the results of present studies on the loading of immunomodulators or nonsteroidal anti-inflammatory drugs to nano-scaled drug delivery systems. For future potential clinical use, research should focus on the optimization of drug delivery designs that provide adequate and effective doses with safe and satisfactory pharmacokinetic and pharmaco-toxic profiles.

Corticosteroids in ophthalmology: drug delivery innovations, pharmacology, clinical applications, and future perspectives

Corticosteroids remain the mainstay of the treatment for various ocular conditions affecting the ocular surface, anterior and posterior segments of the eye due to their anti-inflammatory, anti-oedematous, and anti-neovascularization properties. Prednisolone, prednisolone acetate, dexamethasone, triamcinolone acetonide, fluocinolone acetonide, and loteprednol etabonate are amongst the most widely used ophthalmic corticosteroids. Corticosteroids differ in their activity and potency in the eye due to their inherent pharmacological and pharmaceutical differences. Different routes and regimens are available for ocular administration of corticosteroids. Conventional topical application to the eye is the route of choice when targeting diseases affecting the ocular surface and anterior segment, while periocular, intravitreal, and suprachoroidal injections can be potentially effective for posterior segment diseases. Corticosteroid-induced intraocular pressure elevation and cataract formation remain the most significant local risks following topical as well as systemic corticosteroid administration. Invasive drug administration via intracameral, subconjunctival, and intravitreal injection can enhance ocular bioavailability and minimize dose and dosing frequency of administration, yet may exacerbate ocular side effects of corticosteroids. This review provides a critical appraisal of the ophthalmic uses of corticosteroid, routes of administration, drug delivery fundamentals and novel ocular implantable steroid delivery systems, factors influencing side effects, and future perspectives for ocular corticosteroid therapy.

Pentacam corneal densitometry-guided treatment of adenoviral corneal subepithelial infiltrates: a comparative study between transepithelial phototherapeutic keratectomy and topical tacrolimus

PURPOSE

To compare the changes in the measurement of corneal densitometry and total corneal higher-order aberrations (HOAs) between topical tacrolimus and transepithelial phototherapeutic keratectomy (Te-PTK) in the treatment of adenoviral corneal subepithelial infiltrates (SEIs).

SUBJECT AND METHODS

This is an interventional prospective randomized study, including 63 eyes of 35 patients with symptomatic adenoviral corneal SEIs for at least 6 months. All patients underwent previous topical steroid therapy associated with unsatisfactory response and/or complications. Patients were assigned into three groups: (1) Te-PTK group: Te-PTK with MMC 0.02% was performed by a Technolas; Teneo excimer laser; (2) tacrolimus group: tacrolimus 0.03% ointment was applied once daily for 2-6 months; the endpoint of treatment was based on the improvement in the corneal densitometry, BCVA, and OSDI; and (3) control group: no intervention was done. BCVA, corneal densitometry, and total corneal higher-order aberrations (HOAs) evaluation using Pentacam HR were done at the baseline, 1 week, and then 1, 3, 6, and 12 months of the study.

RESULTS

The study population was similar between all groups. The mean follow-up was 12.75 ± 0.9 months. Bilateral corneal SEI was recorded at 80%. At 12-month follow-ups, the mean BCVA improved in both the Te-PTK and tacrolimus groups without significant changes in the control group. The mean corneal densitometry of the anterior, central, and total cornea decreased significantly in the Te-PTK and tacrolimus groups. HO-RMS and total RMS decreased significantly in the Te-PTK and tacrolimus groups. BCVA, corneal densitometry (anterior, central, and total cornea), and corneal aberrations (total coma, total trefoil, HO-RMS, and total RMS) values were significantly better for the Te-PTK and tacrolimus groups than the control group. There were no statistically significant differences between Te-PTK and tacrolimus groups in terms of BCVA, corneal densitometry, corneal HOA, and the persistence of corneal SEIs. The persistence of corneal SEIs was significantly lower in Te-PTK and tacrolimus groups than the control group.

CONCLUSION

Te-PTK and topical tacrolimus are effective methods for the treatment of adenoviral corneal SEIs improving visual acuity, corneal densitometry, and corneal HOA. The densitometry program of the Pentacam may give an objective guide for the treatment of adenoviral corneal SEIs.

TRIAL REGISTRATION

ClinicalTrials.gov ID is NCT04267991.

Stability characterization, kinetics and mechanism of tacrolimus degradation in cyclodextrin solutions

Tacrolimus is a macrolide lactone and potent immunosuppressant. It is highly lipophilic and has very limited aqueous solubility. Tacrolimus is highly susceptible to hydrolysis which results in very limited stability in aqueous solutions. Besides this, tacrolimus also undergoes dehydration and epimerization. Cyclodextrin (CD) complexation can increase the solubility and stability of hydrophobic drugs in aqueous solutions through the formation of drug/CD complexes. The aim of this study was to investigate degradation kinetics, mechanism and stability of tacrolimus in aqueous CD solutions, with the ultimate goal of developing an aqueous vehicle for ophthalmic delivery. For this, phase-solubility and kinetic studies in aqueous solutions containing different CDs at different pH values were performed. Mass spectrometry studies were also performed to elucidate the degradation mechanism of the drug in aqueous CD solution. The study showed that the drug has maximum stability between pH 4 and 6 and hydrolysis was the main cause of tacrolimus degradation in aqueous 2-hydroxypropyl-βCD (HPβCD) solutions. βCD and its derivatives were the better CD solubilizers for tacrolimus. The solubility and stability studies were further conducted with CD and surfactants, which is tyloxapol, tween 80 and poloxamer 407, where the combination provided better results compared to individual components.

Aqueous penetration of topical tacrolimus

Purpose

To evaluate the penetration of topical tacrolimus 0.05% into the aqueous humor.

Observations

A total of four patients scheduled for routine cataract surgery were included prospectively. We excluded patients with corneal pathology or ocular surface diseases. Topical tacrolimus 0.05% was compounded at our facility. It was dosed every 1 min for 5 min an hour before the aqueous was sampled. Aqueous samples were collected at the time of cataract surgery and were subjected to detection of presence and level of tacrolimus. There were 2 male and 2 female patients. The age range was 58–73 years with a mean age of 66 years. Tacrolimus was detected in the aqueous humor in all patients. The concentration of tacrolimus in the aqueous ranged from 2.6 to 5.6 ng/ml (mean 4.15 ± 1.18 ng/ml). In all patients, the aqueous tacrolimus concentration was greater than the minimal therapeutic level. The study was registered at clinicaltrials.gov (registration number is NCT02794610).

Conclusions and Importance

Tacrolimus was detected in the aqueous humor following topical application. Topical tacrolimus may be a promising steroid-sparing modality for the treatment of anterior uveitis.

Cationic nanoemulsions with prolonged retention time as promising carriers for ophthalmic delivery of tacrolimus

Tacrolimus, also known as FK506, is a first-line drug for the topical treatment of immune-mediated inflammatory anterior ocular diseases (IIAODs). However, due to its limited water solubility, hydrophobic nature and relatively high molecular weight, topical application of FK506 features poor bioavailability. Numbers of formulations have been attempted to enhance the erratic bioavailability of FK506 through various techniques. But until now, none of them could satisfy the clinical needs completely. Here, a novel formulation of FK506, FK506-loaded cationic nanoemulsions (FK506 CNE), was developed to prolong the precorneal residence time of FK506, thereby enhancing the bioavailability of FK506 for IIAODs therapy. FK506 CNE was prepared by high-pressure homogenization, and its composition was screened and optimized by single-factor experiments. The FK506 CNE showed spherical morphology with a mean diameter of 178.8 ± 2.7 nm and a zeta potential of +25.6 ± 0.6 mV. Results from in vivo gamma scintigraphy studies proved that the precorneal residence time of FK506 CNE was significantly increased, compared with FK506-loaded neutral nanoemulsions (FK506 NE) and saline. The data of aqueous humor pharmacokinetic study in rabbits showed that the relative bioavailability of FK506 CNE was 1.68-fold and 1.77-fold of FK506 NE and the marketed FK506 eye drops (Talymus®), respectively. Finally, hematoxylin and eosin staining images and in vitro cytotoxicity data confirmed the safety of the FK506 CNE. Taking all these into consideration, we propose that FK506 CNE is a promising topical ophthalmic nanoformulation for the management of IIAODs.

Topical Tacrolimus as an adjunct to Conventional Therapy for Stromal Herpetic Keratitis: a Randomized Clinical Trial

Purpose

This study investigates the effects of 0.05% topical tacrolimus as an adjunct therapy for patients with non-necrotizing herpetic stromal keratitis (HSK).

Methods

Patients with non-necrotizing HSK, referred to the Cornea Clinic at Hospital in Rasht, Iran, between September 2016 and February 2018, were randomly assigned to two groups. The case group (N = 25) and the control group (N = 25) received conventional treatment with systemic acyclovir and topical prednisolone. The case group (N = 25) additionally received 0.05% tacrolimus eye drops four times a day for one month. Complete ocular examinations, including best-corrected visual acuity (BCVA) assessment, intraocular pressure (IOP) measurement, slit lamp biomicroscopy, and photo slit lamp imaging, were performed before treatment, and 3, 7, 14, 21, and 28 days after the intervention.

Results

The mean age of the patients was 46.2 ± 12.9 years, and 70% of the patients were male. There was no difference between the groups in terms of age, sex, and baseline ocular measurements (P> 0.05). The case group had a lower mean logarithm of the minimum angle of resolution (LogMAR) for BCVA, lower grading scores, and steeper decreasing trends for corneal haziness, edema, neovascularization, and epitheliopathy compared to the control group after the second week (P< 0.05), while IOP remained unchanged between groups (P> 0.05).

Conclusion

The addition of 0.05% topical tacrolimus enhances visual acuity and reduces corneal inflammation, neovascularization, and scarring; thus, it can used as an appropriate adjunct treatment for patients with HSK.

Ocular Co-Morbidities of Atopic Dermatitis. Part II: Ocular Disease Secondary to Treatments

Treatments used for managing atopic dermatitis (AD) may have adverse ocular effects that permanently affect vision. The objective of this review is to raise awareness among dermatologists regarding the potential ocular adverse effects of various AD therapies, including corticosteroids, calcineurin inhibitors, an interleukin-4 receptor α (IL-4Rα) antagonist, and phototherapy. Pertinent potential short- and long-term risks of these therapies include elevations in intraocular pressure from use of topical corticosteroids and conjunctivitis from use of dupilumab. Since some of these adverse effects may not exhibit symptomatology until permanent vision impairment occurs, it is important for dermatologists to understand these risks and proactively ensure their patients are receiving appropriate measures to prevent them.

Corneal Toxicity of Topical Tacrolimus Ointment in Mice with Corneal Epithelial Injury

Purpose: To investigate the effect of tacrolimus ointment on corneal epithelium. Methods: Eight-week-old male BALB/c mice were divided into 3 groups. In group 1, no injury was made. In group 2, the central 2-mm corneal epithelium was scraped off. In group 3, the whole corneal and limbal epithelium was removed after absolute ethanol application. In each group, the corneas were observed and treated daily with 0.03% or 0.1% tacrolimus ointment (Protopic^®). The viability of cultivated human corneal epithelial cells was also examined after 24-h incubation with various concentrations of tacrolimus. Results: Tacrolimus ointment significantly delayed the epithelial healing in corneas with epithelial injuries (groups 2 and 3) in dose- and frequency-dependent manners, whereas it did not have any effects on uninjured corneas (group 1). The proportion of terminal deoxynucleotidyl transferase-mediated nick end labeling-positive cells and mRNA levels of inflammatory cytokines were higher in tacrolimus-treated corneas, compared with controls. Tacrolimus did not directly reduce the viability of corneal epithelial cells in culture. Conclusions: Topical application of tacrolimus ointment onto the ocular surface induced toxicity in the cornea with epithelial defects through the impairment of epithelial healing and induction of apoptosis.

Preclinical characterization and clinical evaluation of tacrolimus eye drops

Severe allergic ocular diseases as atopic keratoconjunctivitis can induce corneal damage due to inflammatory substances released from giant papillae. Tacrolimus eye drops are one of the current therapeutic alternatives for its treatment. This work is aimed at developing and characterizing a 0.03% tacrolimus ophthalmic formulation, which was introduced in three types of vehicles (BBS, PVA and Hyaluronic Acid). For this, we have performed in vitro (stability studies) and in vivo assays (corneal permanence time measured directly by Positron Emission Tomography) of three potential formulations. Next, the best formulation was selected, and its toxicological profile and clinical effectiveness have been evaluated. The biopermanence studies (direct measurements and PET/CT) showed that the formulations with PVA and Hyaluronic Acid present more retention time on the ocular surface of rats than PBS. From the stability study, we have determined that tacrolimus with PVA in cold storage is the best option. Tacrolimus with PVA has shown lower cytotoxicity than cyclosporine at early times. On the other hand, the pilot study performed has shown significant improvements in patients, with no noticeable adverse reactions. Based on stability, biopermanence, safety and clinical effectiveness studies, we concluded that tacrolimus-PVA eye drops are a suitable candidate for its clinical application in inflammatory ophthalmology diseases.

Topical Tacrolimus 0.03% for Maintenance Therapy in Steroid-Dependent, Recurrent Phlyctenular Keratoconjunctivitis

PURPOSE

To evaluate the efficacy of topical tacrolimus 0.03% as steroid-free maintenance therapy in young patients with severe, recurrent phlyctenular keratoconjunctivitis (PKC).

METHODS

The medical records of 6 eyes of 5 patients (4 children and 1 young adult) with recurrent, steroid-dependent PKC were reviewed. The patients were treated with combined application of topical steroids and tacrolimus 0.03% in the active phase and maintained on topical tacrolimus alone after remission.

RESULTS

The clinical signs, symptoms, and visual acuities resolved in all patients after 25.2 ± 16.9 days of combined treatment with steroids and tacrolimus. After disease remission, the patients were maintained on topical tacrolimus 0.03% once daily alone for 8.4 ± 4.7 months, and no recurrence occurred during 10.6 ± 1.9 months of follow-up. Tacrolimus was successfully discontinued in 2 patients without further recurrence. There were no ocular side effects related to the use of topical tacrolimus.

CONCLUSIONS

Topical tacrolimus 0.03% was effective in maintaining long-term remission in patients with recurrent, steroid-dependent PKC.

Clinical implications of mast cell involvement in allergic conjunctivitis

The conjunctiva is a common site for the allergic inflammatory response due to it being highly vascularized, having constant exposure to environmental pollutants and allergenic pollens and having a unique conjunctival associated lymphoid tissue. The primary morbidity of anterior surface conjunctival disorders that include allergic conjunctivitis and tear film disorders is associated with its high frequency of involvement rather than its severity, although the more chronic forms can involve the cornea and lead to sight-threatening conditions. Ocular allergy is associated with IgE-mediated mast cell activation in conjunctival tissue leading to the release of preformed mediators including histamine and proteases and subsequent de novo formation of lipid-derived mediators and cytokines that trigger a cascade of cellular and molecular events leading to extensive migration and infiltration of inflammatory cells to the ocular surface. The trafficking of neutrophils, eosinophils, and lymphocytes to the ocular surface is due to establishing various chemokine gradients (mainly CCL11, CCL24, CCL5, MCP-3, and MCP-4), cell surface expression of adhesion molecules (such as VCAM-1 the ligand for VLA-4), and leukocyte adhesion to vascular endothelium. The release of preformed mediators underlies the acute ocular surface response while the secondary influx of inflammatory cells leading to the recruitment and activation of eosinophils and the subsequent activation of Th2 and Th1 lymphocytes at the level of the conjunctiva reflects the late-phase reaction.

Hair Follicle Immune Privilege Revisited: The Key to Alopecia Areata Management

The collapse of the immune privilege (IP) of the anagen hair bulb is now accepted as a key element in AA pathogenesis, and hair bulb IP restoration lies at the core of AA therapy. Here, we briefly review the essentials of hair bulb IP and recent progress in understanding its complexity. We discuss open questions and why the systematic dissection of hair bulb IP and its pharmacological manipulation (including the clinical testing of FK506 and α-melanocyte-stimulating hormone analogs) promise to extend the range of future therapeutic options in AA and other IP collapse-related autoimmune diseases.

Systemic lupus erythematosus and ocular involvement: an overview

Systemic lupus erythematosus (SLE) is a multisystem autoimmune disease of undefined etiology and with remarkably heterogeneous clinical features. Virtually any organ system can be affected, including the eye. SLE-related eye involvement can be diagnosed in approximately one-third of the patients and is usually indicative of disease activity. An early diagnosis and the adoption of suitable therapeutic measures are necessary to prevent sight-threatening consequences, especially in patients with juvenile SLE. Periocular lesions, such as eyelid involvement and orbital inflammation, are relatively rare and, in case of orbital masses, may require a biopsy control. Keratoconjunctivitis sicca or secondary Sjögren's syndrome is the most frequent ophthalmic manifestation of SLE. According to its variable severity, lubricating tear drops may be sufficient in mild cases, whereas cyclosporine-A ophthalmic solution, glucocorticoids (GCs), methotrexate, and/or other immunosuppressive drugs may be required in the more severe cases. Partial occlusion of the lacrimal punctum by thermal cautery is rarely applied. Although uncommon, episcleritis and scleritis can sometimes be detected as an initial finding of SLE and reveal themselves as moderate to intense ocular pain, redness, blurred vision, and lacrimation. Unilateral or more often bilateral retinopathy is responsible for visual loss of variable severity and is ascribed to vasculitis of the retinal capillaries and arterioles. In addition to the combined treatment suitable for all patients with active SLE, intravitreal bevacizumab should be considered in cases of severe vaso-occlusive retinopathy and laser photocoagulation in cases of neovascularization. Purtscher-like retinopathy is likely ascribable to the formation of microemboli that results in retinal vascular occlusion and microvascular infarcts. Choroidal disease is characterized by monolateral or bilateral blurred vision. Because of the choroidal effusion, retinal detachment and secondary angle-closure glaucoma may occur. Ischemic optic neuropathy is characterized by acute-onset and progressive binocular visual impairment as a consequence of occlusion of the small vessels of the optic nerves due to immune complex vasculitis. Intravenous GC boluses followed by oral GCs and/or, in case of recurrence, intravenous cyclophosphamide and/or rituximab are commonly employed. Neovascularization can be treated by intravitreal bevacizumab and progression of retinal ischemic areas by retinal laser photocoagulation. Ocular adverse events (AE) have been described following the long-term administration of one or more of the drugs presently used for the treatment of SLE patients. Posterior subcapsular cataracts and secondary open-angle glaucoma are common AE of the prolonged GC administration. The long-term administration of hydroxychloroquine (HCQ) sulfate is well known to be associated with AE, such as vortex keratopathy and in particular the often irreversible and sight-threatening maculopathy. Length of administration > 5 years, > 1000 g total HCQ consumption, > 6.5 mg/kg daily dosing, coexistence of renal disease, and preexisting maculopathy are all considered risk factors for HCQ-induced retinopathy. Ocular AE of additional immunosuppressive and biological agents are still poorly known, given the worldwide more limited experience with their long-term use. A thorough ophthalmological control is strongly recommended at closer intervals for all SLE patients, in step with the total length of exposure to the drugs and the cumulative dose administered.