Corneal toxicity from topical ocular and systemic medications

Drug-Related Keratitis: A Real-World FDA Adverse Event Reporting System Database Study

Purpose

This study aimed to assess the drug risk of drug-related keratitis and track the epidemiological characteristics of drug-related keratitis.

Methods

This study analyzed data from the U.S. Food and Drug Administration (FDA) Adverse Event Reporting System (FAERS) database from January 2004 to December 2023. A disproportionality analysis was conducted to assess drug-related keratitis with positive signals, and drugs were classified and assessed with regard to their drug-induced timing and risk of drug-related keratitis.

Results

A total of 1606 drugs were reported to pose a risk of drug-related keratitis in the FAERS database, and, after disproportionality analysis and screening, 17 drugs were found to significantly increase the risk of drug-related keratitis. Among them, seven were ophthalmic medications, including dorzolamide (reporting odds ratio [ROR] = 3695.82), travoprost (ROR = 2287.27), and brimonidine (ROR = 2118.52), and 10 were non-ophthalmic medications, including tralokinumab (ROR = 2609.12), trazodone (ROR = 2377.07), and belantamab mafodotin (ROR = 680.28). The top three drugs having the highest risk of drug-related keratitis were dorzolamide (Bayesian confidence propagation neural network [BCPNN] = 11.71), trazodone (BCPNN = 11.11), and tralokinumab (BCPNN = 11.08). The drug-induced times for non-ophthalmic medications were significantly shorter than those for ophthalmic medications (mean days, 141.02 vs. 321.96, respectively; P < 0.001). The incidence of drug-related keratitis reached its peak in 2023.

Conclusions

Prevention of drug-related keratitis is more important than treatment. Identifying the specific risks and timing of drug-induced keratitis can support the development of preventive measures.

Translational Relevance

Identifying the specific drugs related to medication-related keratitis is of significant importance for drug vigilance in the occurrence of drug-related keratitis.

Understanding Ocular Graft-Versus-Host Disease to Facilitate an Integrated Multidisciplinary Approach

Ocular Graft-versus-Host Disease (oGVHD) remains a challenging and potentially devastating complication following allogeneic hematopoietic stem cell transplantation (allo-HSCT). It significantly impacts the quality of life of affected survivors, however, is often underrecognized particularly during the early stages. Targeting all providers in the HSCT community who see patients regularly and frequently for their post-allo-HSCT care, this review and opinion piece introduces the basic concepts of ocular surface pathophysiology, dissects the different stages of clinical presentation of oGVHD, explains why the current diagnostic criteria tend to capture the late disease stages, highlights the warning signs of early disease development, in hope to facilitate prompt referral of oGVHD suspects for ocular specialist care. In addition to introducing a comprehensive list of treatment options, this review emphasizes basic therapeutic strategy and options that are safe and effective to be initiated by any care provider. We believe in empowering the patients as well as the care providers beyond disciplinary boundaries, in order to provide the most cohesive and integrated care to our patients in a multidisciplinary approach.

Solanum nigrum Toxicity and Its Neuroprotective Effect Against Retinal Ganglion Cell Death Through Modulation of Extracellular Matrix in a Glaucoma Rat Model

Purpose: Glaucoma is a complex degenerative optic neuropathy characterized by loss of retinal ganglion cells (RGCs) leading to irreversible vision loss and blindness. Solanum nigrum has been used for decades in traditional medicine system. However, no extensive studies were reported on its antiglaucoma properties. Therefore, this study was designed to investigate the neuroprotective effects of S. nigrum extract on RGC against glaucoma rat model. Methods: High performance liquid chromatography and liquid chromatography tandem mass spectrometry was used to analyze the phytochemical profile of aqueous extract of S. nigrum (AESN). In vitro, {3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide} (MTT) and H2DCFDA assays were used to determine cell viability and reactive oxygen species (ROS) production in Statens Seruminstitut Rabbit Cornea cells. In vivo, AESN was orally administered to carbomer-induced rats for 4 weeks. Intraocular pressure, antioxidant levels, and electrolytes were determined. Histopathological and immunohistochemical analysis was carried out to evaluate the neurodegeneration of RGC. Results: MTT assay showed AESN exhibited greater cell viability and minimal ROS production at 10 μg/mL. Slit lamp and funduscopy confirmed glaucomatous changes in carbomer-induced rats. Administration of AESN showed minimal peripheral corneal vascularization and restored histopathological alterations such as minimal loss of corneal epithelium and moderate narrowing of the iridocorneal angle. Immunohistochemistry analysis showed increased expression of positive BRN3A cells and decreased matrix metalloproteinase (MMP)-9 activation in retina and cornea, whereas western blot analysis revealed downregulation of extracellular matrix proteins (COL-1 and MMP-9) in AESN-treated rats compared with the diseased group rats. Conclusions: AESN protects RGC loss through remodeling of MMPs and, therefore, can be used for the development of novel neurotherapeutics for the treatment of glaucoma.

Clinical features and management of keratoconjunctivitis associated with inadequate tear drainage

OBJECTIVE

To describe clinical features and management of toxic keratoconjunctivitis associated with punctal and (or) canaliculus stenosis (toxic soup syndrome).

DESIGN

Retrospective observational case series.

METHODS

Electronic medical record database search for the keywords "toxic soup syndrome" and retrospective chart review were performed. Thirty-five eyes of 25 patients were seen at a tertiary cornea clinic between January 2017 and December 2021. Sex, age, distance-corrected visual acuity, topical medications, symptoms, clinical signs, and outcomes after medical and surgical interventions were analyzed. The main outcome measured was improvement in ocular surface signs and symptoms after interventions.

RESULTS

Overall, 35 eyes of 25 patients with a mean age of 66.8 ± 12.8 years, of which 72% were female, were included. The primary complaint was hyperemia and epiphora in all patients. Rosacea or meibomian gland disease were present in all patients, 7 (28%) had glaucoma, and 7 (28%) developed limbal stem cell deficiency. Twenty-two patients (88%) were using topical medications on presentation. All eyes had either punctal plugs, cauterized puncta, or punctal and (or) canaliculus stenosis. Management of all patients consisted of suspension of all preserved topical medications and institution of some type of anti-inflammatory therapy. Nineteen patients (76%) improved after improvement of lacrimal drainage. One patient with severe resistance in the canaliculus required ongoing preservative-free topical steroids.

CONCLUSIONS

Chronic drug-induced or pooled inflammatory mediators causing toxic conjunctivitis may be aggravated by punctal and (or) canaliculus stenosis, leading to toxic soup syndrome. Clearance of punctal obstruction leads to improvement in most patients.

Topical glycerine for corneal clouding during retinal laser photocoagulation for retinopathy of prematurity

AIM

To document the use of topical glycerine to reduce corneal edema in cases of retinopathy of prematurity (ROP) undergoing laser photocoagulation (PHC).

METHODS

Thirty-two eyes of 16 babies (9 males) with a mean gestational age of 30 weeks, mean gestational weight of 1242 grams underwent PHC for Type 1 (zone 1 disease) retinopathy of prematurity. All babies received a single PHC session. Twenty eyes of 10 babies received intravitreal anti-VEGF injection, 1-3 weeks before PHC session. All patients received a single drop of glycerine during the PHC session to clear the corneal clouding. All patients underwent PHC to the avascular area right up to the ora serrata. Patients were seen at one week and one month to assess the adequacy of laser PHC.

RESULTS

We were able to complete the PHC for all babies in a single session without any ocular or systemic adverse events. We did not find any skip lesions at follow-up, and the second session of laser PHC was not required in any eyes.

CONCLUSION

Topical glycerine is safe and effective to clear corneal clouding in eyes undergoing laser PHC for retinopathy of prematurity.

[Use of dexpanthenol in corneal damage]

Issues of regeneration of the cornea, which is the most vulnerable structure of the eyeball, suffering from various diseases and injuries, burns, when wearing contact lenses and glaucoma, are highly relevant for ophthalmologists. It is also necessary to minimize damage and stimulate corneal epithelization during and after the use of steroidal and non-steroidal anti-inflammatory drugs, antibacterial drugs and antiseptics, which have a cytotoxic effect and often inhibit regeneration processes, potentially even leading to the development of corneal epithelial defects. This review analyzes the effectiveness of a promising drug 5% dexpanthenol in terms of improving the reparative processes and the function of epithelial cells.

Promising Role of Silk-Based Biomaterials for Ocular-Based Drug Delivery and Tissue Engineering

Silk is a wonderful biopolymer that has a long history of medical applications. Surgical cords and medically authorised human analogues made of silk have a long history of use in management. We describe the use of silk in the treatment of eye diseases in this review by looking at the usage of silk fibroin for eye-related drug delivery applications and medication transfer to the eyes. During this ancient art endeavour, a reduced engineering project that employed silk as a platform for medicine delivery or a cell-filled matrix helped reignite interest. With considerable attention, this study explores the present usage of silk in ocular-based drug delivery. This paper also examines emerging developments with the use of silk as a biopolymer for the treatment of eye ailments. As treatment options for glaucoma, diabetic retinopathy, retinitis pigmentosa, and other retinal diseases and degenerations are developed, the trans-scleral route of drug delivery holds great promise for the selective, sustained-release delivery of these novel therapeutic compounds. We should expect a swarm of silk-inspired materials to enter clinical testing and use on the surface as the secrets of silk are unveiled. This article finishes with a discussion on potential silk power, which adds to better ideas and enhanced ocular medicine delivery.

Effects of systemic targeted immunosuppressive therapy on ocular surface

PURPOSE OF REVIEW

The purpose of this review is to give an overview of the corneal manifestations of targeted systemic immunotherapies and provide guidelines for management when applicable.

RECENT FINDINGS

The advent of newer systemic immunosuppressive therapy has resulted in the need for more awareness of potential ocular side effects. Side effects can range from vortex keratopathy as seen with the tyrosine kinase inhibitors, to epithelial microcysts as reported in the use of cytarabine and belantamab mafodotin, spontaneous corneal perforations have been reported with programmed death 1 inhibitors, while eyelid cicatrization has been reported epidermal growth factor inhibitors. Several immunomodulatory therapies result in conjunctivitis which tends to respond to topical lubrication and corticosteroid treatment. Most manifestations listed in the review are limited to the anterior segment; however, some may lead to retinal and optic nerve changes which can be permanently damaging.

SUMMARY

Ocular surface and corneal changes secondary to systemic immunosuppression can affect main components of the ocular surface. Although most adverse effects are reversible, few changes can be permanent and therefore close ophthalmologic monitoring is necessary.

Polymer based sustained drug delivery to the ocular posterior segment: barriers and future opportunities for the treatment of neovascular pathologies

There is an increasing momentum in research and pharmaceutical industry communities to design sustained, non-invasive delivery systems to treat chronic neovascular ocular diseases that affect the posterior segment of the eye including age-related macular degeneration and diabetic retinopathy. Current treatments include VEGF blockers, which have revolutionized the standard of care for patients, but their maximum therapeutic benefit is hampered by the need for recurrent and invasive administration procedures. Currently approved delivery systems intended to address these limitations exploit polymer technology to regulate drug release in a sustained manner. Here, we critically review sustained drug delivery approaches for the treatment of chronic neovascular diseases affecting the ocular posterior segment, with a special emphasis on novel and polymeric technologies spanning the spectrum of preclinical and clinical investigation, and those approved for treatment. The mechanism by which each formulation imparts sustained release, the impact of formulation characteristics on release and foreign body reaction, and special considerations related to the translation of these systems are discussed.

Corneal Oedema: Aetiology, Diagnostic Testing, and Treatment

Corneal oedema results from an underlying pathology, which can be diverse in origin, and may be mechanical, dystrophic, or inflammatory, and affect any layer of the cornea. Diagnostic tools such as Scheimpflug imaging and anterior segment optical coherence tomography have standardised quantification of corneal oedema and have become important aids in clinical practice. Timely diagnosis and treatment are key to preventing irreversible damage to the corneal ultrastructure, such as anterior corneal fibrosis or endothelial cell damage. The oedema usually resolves quickly when the underlying cause has been addressed. Symptomatic treatment using hyperosmolar agents has failed to show any benefits in oedema resolution or improvement in visual acuity compared to placebo. In contrast, rho-associated protein kinase (ROCK) inhibitors offer a promising option for medical treatment in cases of endothelial dysfunction, but their safety and efficacy must be further validated in large scale clinical trials. Until then, endothelial or penetrating keratoplasties remain the mainstay treatment where structural changes to the cornea have occurred.

Effect of topical non-steroidal anti-inflammatory drugs on healing times and complications in dogs with spontaneous chronic corneal epithelial defects

BACKGROUND

Little is published regarding topical NSAID effect on corneal healing in dogs. This retrospective cohort study aimed to compare healing times and complications in dogs with spontaneous chronic corneal epithelial defects (SCCED) treated with and without topical non-steroidal anti-inflammatory drugs (NSAID).

METHODS

Medical records of 66 dogs (71 eyes) diagnosed with SCCED between 2008 and 2019 were included. Eyes were divided into: (1) those receiving topical NSAIDs (n = 33) versus (2) those not receiving topical NSAID (n = 38). Follow-up until healed, such as comfortable eye, negative fluorescein stain was required. Use of topical or systemic anti-inflammatories outside of NSAID or presence of ocular disorders or systemic endocrinopathies that may contribute to delayed healing resulted in study exclusion.

RESULTS

Healing times were significantly longer in eyes that received topical NSAID (p = 0.008), however, the use of more topical medications for treatment was also associated with longer healing times (p = 0.001). The majority of eyes in the NSAID group received multiple medications, compared to the non-NSAID group, so it was not possible to separate the effects of NSAID from a number of medications. Complications occurred in three eyes of three dogs within the NSAID group.

CONCLUSIONS

In these canine SCCED eyes, the use of more topical medications, including NSAID, was associated with significantly delayed healing time.

Clinical aspects and prognosis of polymicrobial keratitis caused by different microbial combinations: a retrospective comparative case study

PURPOSE

The purpose of this study is to compare the predisposing factors, clinical findings, treatment results, and prognosis for polymicrobial keratitis.

METHODS

In this retrospective comparative case study, we identified the cases of polymicrobial keratitis from the microbiological records (n = 649) at Balcalı Hospital, Çukurova University (Adana, Turkey; October 2010-2018). We included all the cases of infectious keratitis with two different types of microbial agents and grouped them as follows: group 1 (n = 25), bacterium-fungus coexistence; group 2 (n = 12), herpes simplex virus (HSV) or Acanthamoeba with bacterial infection; and group 3 (n = 7), HSV or Acanthamoeba with fungal infection. We compared the clinical and microbiological characteristics, and treatment outcomes among the groups.

RESULTS

In our study, we found that 44 infectious keratitis cases (6.7%) were of polymicrobial nature. The mean follow-up period was 11.4 ± 17.8 months. In total, 17 different bacteria along with 3 different fungi, HSV, and Acanthamoeba were isolated. The most common bacterium was Staphylococcus epidermidis (25%). Most of the fungal pathogens were filamentous. Patients with initial treatment failure and requiring surgical intervention had larger infiltrates (p = 0.023, p = 0.003, respectively) than other patients. Older age was associated with delayed recovery and poor visual prognosis.

CONCLUSIONS

Bacterial-fungus coexistence is the most common combination among patients, but other combinations should also be considered for suspected polymicrobial etiology. The corneal infiltrate size may be an important indicator of the course of disease and response to treatment. A closer and longer follow-up period should be planned for older patients.

Tear Film Osmolarity, Ocular Surface Disease and Glaucoma: A Review

Glaucoma is the second leading cause of blindness in the world, affecting more than 60 million people globally. In order to reduce the progression of the disease, both medical and surgical treatments are used. Frequent side effects of both treatments include a range of modifications of the ocular surface grouped as the Ocular Surface Disease (OSD), which include Dry Eye Disease (DED). DED and other OSD negatively impact on the success of anti-glaucoma treatments and reduce the adherence to medical therapies. Tear film osmolarity (TFO) is a relatively novel test which has become a hallmark of DED. The aim of this paper was to review the association between OSD, DED and glaucoma in view of published TFO data, and to discuss future fields of research and treatments on the topic of glaucoma iatrogenic damage.

Toxic Keratoconjunctivitis

Toxic keratoconjunctivitis (TK) is an underrecognized complication of ophthalmic drug use and various environmental or occupational exposures. A detailed history and clinical examination are important to identify the offending agent(s). Common drug-related causes of TK include preservatives in ophthalmic medications, topical antimicrobials, and topical anesthetics. Alternatives to benzalkonium chloride as well as preservative-free formulations should be considered in patients requiring long-term topical medication. More advanced cases of TK may require preservative-free topical steroids and/or antibiotics, and occasionally surgical intervention. Early recognition and appropriate management of TK may help prevent permanent ocular and visual damage.

Secukinumab-Associated Crystalline Corneal Deposition

PURPOSE

To describe the first reported case of corneal crystalline deposition associated with the monoclonal antibody secukinumab (Cosentyx; Novartis, Basel, Switzerland) and the subsequent follow-up of the case.

METHODS

Case report.

RESULTS

An 18-year-old man was referred for a corneal opinion 1 year after commencing secukinumab monoclonal antibody therapy for ankylosing spondylitis. Crystalline corneal deposits were identified at a routine optometrist appointment. The same optometrist had documented normal anterior segment examination 2 years earlier. On examination, anterior stromal refractile crystals were visible in both corneas extending out to the limbus. The patient's best-corrected distance visual acuity was 20/20 bilaterally, and he was asymptomatic. Family history and systemic workup for other causes of crystal deposition were negative. By a process of elimination of other etiologies, we concluded that the monoclonal antibody secukinumab was responsible for the deposition. At the 1-year point of treatment with secukinumab, the patient remains asymptomatic and is still undergoing therapy.

CONCLUSIONS

To the best of the authors' knowledge, this is the first report of corneal crystal deposition attributed to secukinumab. The number of monoclonal antibodies in use across multiple medical disciplines is increasing, and corneal specialists may see this presentation more frequently in the future. These drugs provide critical disease-modifying treatment to patients with debilitating systemic pathology. It is important that we understand the natural history of their side effects to allow their full utilization.

Pure Glaucoma Drugs Are Toxic to Immortalized Human Corneal Epithelial Cells, but They Do Not Destabilize Lipid Membranes

PURPOSE

Most pure glaucoma drugs (pGDs) are hydrophobic substances intended to reduce elevated intraocular pressure. The aims of our study were to determine the toxicity of pGDs (brimonidine tartrate, brinzolamide, latanoprost, timolol maleate, and pilocarpine hydrochloride) on ocular surface cells and to establish whether their toxicity is subsequent to cellular membrane destabilization.

METHODS

The toxicity of clinically efficient doses of pGDs was measured at different time points in a cell culture of human corneal epithelial cells using a redox indicator. pGD interaction with the plasma membrane was analyzed using a hemolysis assay and liposome electrokinetic chromatography. The capacity of pGDs to induce endoplasmic reticulum stress was investigated by immunoblotting.

RESULTS

The toxicity assay showed that all pGDs decrease the viability of the epithelial cells to variable degrees. Early toxicity was measured for 4% pilocarpine and 0.15% brimonidine with 60% cell death at 4 hours, whereas 2% pilocarpine and 0.005% latanoprost showed almost 100% toxicity but only after 16 hours. The hemolysis assay and liposome electrokinetic chromatography experiments suggested that interaction between pGDs and lipid membranes is weak and cannot explain cell death through lysis. Immunoblotting revealed that the drugs activate endoplasmic reticulum stress and, with the exception of pilocarpine, have the capacity to induce apoptosis through upregulation of C/EBP homologous protein.

CONCLUSIONS

Our study indicates that all studied pGDs decrease the viability of the corneal epithelial cells, but none of the tested compounds were able to destabilize cellular membranes. The pGDs seem to be internalized and can induce apoptosis through C/EBP homologous protein recruitment.

Treatment with solubilized Silk-Derived Protein (SDP) enhances rabbit corneal epithelial wound healing

There is a significant clinical need to improve current therapeutic approaches to treat ocular surface injuries and disease, which affect hundreds of millions of people annually worldwide. The work presented here demonstrates that the presence of Silk-Derived Protein (SDP) on the healing rabbit corneal surface, administered in an eye drop formulation, corresponds with an enhanced epithelial wound healing profile. Rabbit corneas were denuded of their epithelial surface, and then treated for 72-hours with either PBS or PBS containing 5 or 20 mg/mL SDP in solution four times per day. Post-injury treatment with SDP formulations was found to accelerate the acute healing phase of the injured rabbit corneal epithelium. In addition, the use of SDP corresponded with an enhanced tissue healing profile through the formation of a multi-layered epithelial surface with increased tight junction formation. Additional biological effects were also revealed that included increased epithelial proliferation, and increased focal adhesion formation with a corresponding reduction in the presence of MMP-9 enzyme. These in vivo findings demonstrate for the first time that the presence of SDP on the injured ocular surface may aid to improve various steps of rabbit corneal wound healing, and provides evidence that SDP may have applicability as an ingredient in therapeutic ophthalmic formulations.

Dysfunctional tear syndrome: dry eye disease and associated tear film disorders - new strategies for diagnosis and treatment

Dysfunctional tear syndrome (DTS) is a common and complex condition affecting the ocular surface. The health and normal functioning of the ocular surface is dependent on a stable and sufficient tear film. Clinician awareness of conditions affecting the ocular surface has increased in recent years because of expanded research and the publication of diagnosis and treatment guidelines pertaining to disorders resulting in DTS, including the Delphi panel treatment recommendations for DTS (2006), the International Dry Eye Workshop (DEWS) (2007), the Meibomian Gland Dysfunction (MGD) Workshop (2011), and the updated Preferred Practice Pattern guidelines from the American Academy of Ophthalmology pertaining to dry eye and blepharitis (2013). Since the publication of the existing guidelines, new diagnostic techniques and treatment options that provide an opportunity for better management of patients have become available. Clinicians are now able to access a wealth of information that can help them obtain a differential diagnosis and treatment approach for patients presenting with DTS. This review provides a practical and directed approach to the diagnosis and treatment of patients with DTS, emphasizing treatment that is tailored to the specific disease subtype as well as the severity of the condition.

Therapeutic agents and biocides for ocular infections by free-living amoebae of Acanthamoeba genus

Acanthamoeba keratitis is a sight-threatening infectious disease. Resistance of the cystic form of the protozoan to biocides and the potential toxicity of chemical compounds to corneal cells are the main concerns related to long-term treatment with the clinically available ophthalmic drugs. Currently, a limited number of recognized antimicrobial agents are available to treat ocular amoebic infections. Topical application of biguanide and diamidine antiseptic solutions is the first-line therapy. We consider the current challenges when treating Acanthamoeba keratitis and review the chemical properties, toxicities, and mechanisms of action of the available biocides. Antimicrobial therapy using anti-inflammatory drugs is controversial, and aspects related to this topic are discussed. Finally, we offer our perspective on potential improvement of the effectiveness and safety of therapeutic profiles, with the focus on the quality of life and the advancement of individualized medicine.

In vivo confocal microscopy of toxic keratopathy

Purpose

To explore the morphological characteristics of toxic keratopathy (TK), which clinically presented as superficial punctate keratopathy (SPK), with the application of in vivo laser-scanning confocal microscopy (LSCM), and evaluate its potential in the early diagnosis of TK.

Patients and methods

This was a cross-sectional study involving 16 patients with TK and 16 patients with dry eye (DE), demonstrating SPK under slit-lamp observation, and 10 normal eyes were enrolled in the study. All participants underwent history interviews, fluorescein staining, tear film break-up time (BUT) tests, Schirmer tests, and in vivo LSCM.

Results

The area grading of corneal fluorescein punctate staining was higher in the TK group than the DE group. Measured by in vivo LSCM, superficial epithelial cell density was lower in the TK group than that of DE group. The sub-basal nerve presented lower density and tortuosity in the TK group than the DE group. Most notably, deposits with a snow-like appearance were observed in the epithelium in 12/16 (75.0%) of the TK cases, but none in the DE group (P<0.05).

Conclusion

The SPK in TK patients was characterized by more widespread punctate staining, a lower density of superficial epithelial cells and sub-basal nerves, and a typical snow-like pattern of deposits in the epithelium by LSCM. These features might facilitate early diagnosis of TK from other disorders manifested as SPK.

PERSISTENT CORNEAL EPITHELIAL DEFECT AFTER PARS PLANA VITRECTOMY

PURPOSE

To investigate the incidence, risk factors, and clinical course of persistent corneal epithelial defects (PCED) after pars plana vitrectomy (PPV).

METHODS

The charts of 426 consecutive patients (511 eyes) who received PPV from January 2008 to December 2011 were reviewed. Corneal complications were defined as the presence of corneal epithelial defects, corneal edema, or superficial punctate keratopathy at least 1 week after vitrectomy. The PCED was defined as corneal epithelial defects lasting longer than 2 weeks after vitrectomy despite conventional treatment. The demographic, preoperative, intraoperative, and postoperative data were compared between PCED and non-PCED corneal complication groups to evaluate the risk factors and clinical outcomes.

RESULTS

Postoperative corneal complications developed in 103 of 460 (22.4%) eyes. Diabetes was associated with postoperative corneal epithelial defects (P = 0.021) and superficial punctate keratopathy (P = 0.022) but not corneal edema (P = 0.925). Among 103 eyes with corneal complications, 21 eyes developed PCED. The eyes with PCED had poor final visual acuity, with 23.8% (5/21) of the eyes in the PCED group having visual acuity of 20/200 or better compared with 51.2% (42/82) of the eyes in the non-PCED group (P = 0.024). Logistic regression analysis demonstrated that diabetes mellitus (P = 0.025), use of perfluoropropane (P = 0.001), and assistance of a first-year resident (P = 0.029) were statistically significant risk factors for PCED after PPV. There was also a high incidence of geographic herpes simplex virus epithelial keratitis among recalcitrant PCEDs lasting longer than 4 weeks (36%, 4/11 eyes).

CONCLUSION

The overall incidence of PCED after PPV was 4.8%. Diabetes mellitus, intravitreal tamponade with perfluoropropane, and assistance of a first-year resident were risk factors for PCED after PPV. Persistent corneal epithelial defects after PPV were correlated with poor postoperative visual outcomes. Early and aggressive management is necessary for patients presenting with corneal epithelial defects after vitrectomy to prevent poor outcomes.

Macular ischemia associated with imatinib mesylate therapy for chronic myeloid leukemia

PURPOSE

Imatinib mesylate (Gleevec, East Hanover, NJ) is a drug approved for the treatment of patients with Philadelphia chromosome-positive chronic myeloid leukemia (CML) or Kit-positive gastrointestinal stromal tumors. A case of ischemic maculopathy associated with imatinib mesylate therapy is reported.

METHODS

A 62-year-old woman with a 16-year history of CML was treated with imatinib mesylate, initially at a daily dose of 400 mg that was decreased to 300 mg due to systemic side effects. Several weeks after beginning imatinib mesylate therapy, she developed blurred vision (greater in the left eye than in the right eye).

RESULTS

Fundus examination of both eyes revealed retinal telangiectasia with intraretinal hemorrhages and perifoveal retinal telangiectasia. Fluorescein angiography showed macular ischemia (greater in the left eye than in the right eye). Late perifoveal leakage was present surrounding the macular ischemic zone. Visual acuity was reduced to 20/30 in the right eye and 20/100 in the left eye, which did not improve over 10 months of follow-up.

CONCLUSION

Imatinib mesylate may be associated with ischemic maculopathy that can severely compromise vision. It may be necessary for patients receiving this therapy to be monitored for associated visual symptoms and funduscopic abnormalities.

A review of topically administered mini-tablets for drug delivery to the anterior segment of the eye

OBJECTIVES

The human eye is a unique and intricate structure which has made drug delivery to the eye a formidable undertaking. Anterior-segment eye diseases are ubiquitous, especially among elderly patients, and conventional eye drops, although a first-choice dosage form, are not always an efficient treatment option. The development of novel drug delivery systems for improved treatment is therefore imperative.

KEY FINDINGS

In an attempt to circumvent the obstacles presented by the structure of the eye, advanced systems such as ocular mini-tablets have been developed. In this review, a concerted effort has been made to provide a detailed overview of topically administered ocular mini-tablets and other solid devices for drug delivery to the anterior segment of the eye. These mini-tablets have been shown in vitro and in vivo to have significant advantages in comparison with liquid preparations. This is a step toward attaining better patient convenience and compliance, which are critical factors.

SUMMARY

Solid ophthalmic dosage forms have several advantages that can contribute to assisting with patient compliance and, ultimately, effective disease treatment. In addition to the challenges associated with topical ocular drug delivery, the shortcomings of conventional eye drops, advantages of mini-tablets, and improvements to date to these systems are discussed. The requirement for further advancements in the ocular field is also emphasized.

Toxicity of topical ophthalmic anesthetics

INTRODUCTION

Topical ocular anesthetics are generally well tolerated in clinical settings but have great potential for abuse if used by patients at home. This abuse can lead to significant ocular complications. Topical ocular anesthetic abuse can lead to superficial punctate keratitis, persistent epithelial defects, stromal/ring infiltrates, corneal edema, endothelial damage and ocular inflammation, even when used in a dilute concentration. Patient characteristics may include a healthcare association and/or psychiatric illness. In these instances, patients often do not admit to anesthetic use and are often initially treated for acanthamoeba keratitis. Local anesthetics are thought to cause direct toxicity to the corneal epithelium, stroma and endothelium. This in turn may lead to release of antigens and from there an inflammatory response in the form of infiltrate and edema. It is thought that preservatives in anesthetics may play a further role in toxicity.

AREAS COVERED

The authors provide a brief history on topical ocular anesthetics and review the most recent literature on reported ocular toxicities of topical anesthetics.

EXPERT OPINION

Practitioners must maintain high suspicion for topical ocular anesthetic abuse to identify it early. Topical ocular anesthetic abuse is often misdiagnosed as acanthamoeba keratitis. Early identification is one of the most important factors for a successful outcome. It is also imperative to give proper alternative pain control to avoid topical anesthetic abuse.

Tear clearance and ocular symptoms in patients treated with preservative-free prostaglandins

OBJECTIVES

To assess the effects on dry eye symptoms and tear dynamics of switching from a prostaglandin with a preservative to a preservative-free prostaglandin.

MATERIAL AND METHODS

Fourteen patients (N=28 eyes) with open-angle glaucoma and dry eye symptons, treated with preserved latanoprost, travoprost or bimatoprost were included in this uncontrolled prospective study. Ocular symptoms were analysed using a validated ocular surface disease questionnaire and ocular signs were assessed with tear clearance, Schirmer and tear function index test (TFI=Schirmer/clearance). Patients were assigned to preservative-free tafluprost treatment, and measurements were repeated 4 weeks after change of medication. Wilcoxon test and Spearman correlation coefficient were used in the statistical analysis.

RESULTS

No statistically significant difference in intraocular pressure (IOP) was observed after switching to tafluprost. Mean IOP at baseline was 20.4 mmHg (SD2.2) and after 4 weeks 19.9 mmHg (SD2.6), (P>.05). The mean questionnaire score significantly decreased from 9.7 (SD3.7) at baseline to 5.4 (SD2.7) after one month (P<.001). No significant differences in tear clearance, Schirmer or TFI were found (P>.05). At baseline, tear clearance=0.13 (SD0.07), Schirmer=10.7 mm (SD6) and TFI=80 (48-156). After 4 weeks, tear clearance=0.1(SD0.07), Schirmer=9.5 mm (3.9) and TFI=104 (48-216). A significant association between questionnaire score and tear clearance after 4 weeks was observed (Spearman coefficient=0.62; P=.014).

CONCLUSIONS

Switching from preservative prostaglandin with a preservative to preservative-free tafluprost treatment improves dry eye symptoms and suggests an improvement in TFI.

Pharmacological treatment for infectious corneal ulcers

INTRODUCTION

Cornea ulceration and infectious keratitis are leading causes of corneal morbidity and blindness. Infectious causes are among the most frequent and most severe. Management strategies for bacterial corneal ulcers have changed significantly over the last decades, however with a more limited progress in the treatment and management of nonbacterial, infectious ulcers.

AREAS COVERED

This paper provides an overview of the current principles, strategies and treatment choices for infectious corneal ulcers in adults.

EXPERT OPINION

Topical application with a broad-spectrum antimicrobial remains the preferred method for the pharmacological management of infectious corneal ulcers. Increasing reports of clinical failures and in vitro resistance to antibiotics to treat the most common infectious (bacterial) corneal ulcers are increasing concerns. New approaches for improvement in the pharmacological management of corneal ulcers should focus on strategies for a more rational and evidence-based use of current antimicrobials and development of products to modulate the host immune response and to neutralize microbial toxins and other immune modulators.

Eye

The Eye chapter of the 3rd edition of Haschek and Rousseaux’s Handbook of Toxicologic Pathology brings a comprehensive description of pathological processes affecting the ocular tissues in the most commonly used laboratory animals and their correlations with human diseases of interest in toxicology. Also presented are detailed descriptions of the structure and function of the different ocular tissues, the most advanced techniques applied in the toxicological evaluation of the eye, useful animal models of human disease, and known mechanisms of ocular toxicity. The introductory sections of the chapter also feature such essential topics as ocular embryology, an overview of clinical ophthalmic evaluation, and eye-specific techniques of tissue processing.

Ethyl pyruvate ameliorates endotoxin-induced corneal inflammation

PURPOSE

The purpose of this study was to evaluate the anti-inflammatory effect of ethyl pyruvate (EP) in a mouse model of lipopolysaccharide (LPS)-induced corneal inflammation.

METHODS

LPS was injected intrastromally into the corneas of C57BL/6 mice followed by treatment with a solution of 2.5% EP in 0.2% hydroxypropyl methylcellulose (HPMC) every 90 minutes during the course of 12 hours. Prednisolone acetate 1% solution (PRED FORTE) was used as a positive control. Mice were sacrificed after 3 days, and corneas were examined by in vivo confocal microscopy and analyzed for infiltrated cells by flow cytometry. Gr-1, TNF-α, and pNF-κB-p65 were detected immunohistochemically, and TNF-α, IL-6, and IL-1β levels were quantified by ELISA.

RESULTS

LPS-induced haze in mice corneas was decreased by 2-fold upon EP treatment; however, it was not changed upon PRED FORTE treatment. Flow cytometry and immunohistochemistry showed infiltration of leukocytes in the LPS-treated corneas; among the infiltrated cells, neutrophils (Gr-1+ and CD11b+) and macrophages (F4/80+ and CD11b+) were 3403.4- and 4.5-fold higher in number, respectively, than in vehicle-treated control corneas. EP or PRED FORTE treatment of LPS-injected corneas decreased the number of neutrophils 7.5- and 7.2-fold and macrophages by 5.6- and 3.5-fold, respectively. Both EP and PRED FORTE decreased TNF-α and IL-6 expression considerably, and to a lesser extent IL-1β expression, in the LPS-treated corneas.

CONCLUSIONS

The present study demonstrated that EP reduces LPS-induced inflammation in the cornea and thus may have a potential therapeutic application in the inhibition of corneal inflammation.

Prevalence of signs and symptoms of ocular surface disease in individuals treated and not treated with glaucoma medication

BACKGROUND

  To determine the prevalence of signs and symptoms of ocular surface disease in two hospital-based cohorts; glaucoma patients and non-glaucoma patients.

DESIGN

  A cross-sectional, comparative case series.

PARTICIPANTS

  Glaucoma patients (n = 300) prescribed topical glaucoma medications for ≥6 months were compared with control patients (n = 100) who were not applying prescribed topical medications.

METHODS

  A validated self-report questionnaire was used to elicit the extent of ocular symptoms. Signs of ocular surface and eyelid disease were assessed along with medication history.

MAIN OUTCOME MEASURES

  Signs and symptoms of ocular surface pathology were determined including the tear film break-up time, fluorescein staining of the cornea and conjunctiva, meibomian gland dysfunction and Schirmer's test.

RESULTS

  A significant increase in the prevalence of ocular surface disease signs was observed in the glaucoma population, 70.3%, compared with controls, 33% (P < 0.001). The overall prevalence of clinically significant ocular surface disease symptoms was not significantly different between cohorts, 30.7% versus 24.0%, respectively (P = 0.252). Logistic regression analysis showed that the number of anti-glaucoma medications and duration of therapy were key predictors of significant ocular surface disease signs in the glaucoma group. There was no significant correlation between signs and symptoms of ocular surface disease in either group after adjusting for age and gender.

CONCLUSIONS

  Signs and symptoms of ocular surface disease are relatively common in older patients, but signs of ocular surface disease are significantly higher in individuals who instil topical glaucoma therapy.

Ophthalmic preservatives: focus on polyquaternium-1

INTRODUCTION

Ophthalmic preservatives, such as polyquaternium-1 (PQ-1), are critical for the inhibition of growth of microbial contaminants in multi-dose bottles of topical medications. These antimicrobial agents must have a high efficacy against pathogenic organisms, while maintaining a favorable tolerability and safety profile.

AREAS COVERED

This review focuses on the ophthalmic preservative PQ-1. For comparison purposes, the most commonly used preservative, benzalkonium chloride (BAK), is also discussed. This survey focuses primarily on data collected during the past 10 years.

EXPERT OPINION

Effective drug delivery requires more than just an active ingredient that achieves its desired biological effect on end-target tissues. In addition, drugs must be stable in the containers that they are stored in, and must possess minimal undesired local and systemic side effects that can cause patients to decrease their adherence. In addressing these concerns, specifically in topical ophthalmic drops, one must take into account the active ingredients, vehicle components and preservatives. Medications with fewer adverse effects may lead to enhanced adherence to therapy; therefore, the induction of such adverse outcomes must be considered by physicians when treating patients with chronic ocular disease. Although BAK will continue to be used in ophthalmic medications, due to its familiarity and compatibility with a broad range of topical ocular formulations, PQ-1 is certainly a viable alternative in the preservative formulary armamentarium.