Ocular injury progression and cornea histopathology from chloropicrin vapor exposure: Relevant clinical biomarkers in mice

Ocular tissue is highly sensitive to chemical exposures. Chloropicrin (CP), a choking agent employed during World War I and currently a popular pesticide and fumigating agent, is a potential chemical threat agent. Accidental, occupational, or intentional exposure to CP results in severe ocular injury, especially to the cornea; however, studies on ocular injury progression and underlying mechanisms in a relevant in vivo animal model are lacking. This has impaired the development of effective therapies to treat the acute and long-term ocular toxicity of CP. To study the in vivo clinical and biological effects of CP ocular exposure, we tested different CP exposure doses and durations in mice. These exposures will aid in the study of acute ocular injury and its progression as well as identify a moderate dose to develop a relevant rodent ocular injury model with CP. The left eyes of male BALB/c mice were exposed to CP (20% CP for 0.5 or 1 min or 10% CP for 1 min) using a vapor cap, with the right eyes serving as controls. Injury progression was evaluated for 25 days post-exposure. CP-exposure caused a significant corneal ulceration and eyelid swelling which resolved by day 14 post exposure. In addition, CP-exposure caused significant corneal opacity and neovascularization. Development of hydrops (severe corneal edema with corneal bullae) and hyphema (blood accumulation in the anterior chamber) was observed as advanced CP effects. Mice were euthanized at day 25 post-CP-exposure, and the eyes were harvested to further study the corneal injury. Histopathological analyses showed a significant CP-induced decrease in corneal epithelial thickness and increased stromal thickness with more pronounced damage, including stromal fibrosis, edema, neovascularization, trapped epithelial cells, anterior and posterior synechiae, and infiltration of inflammatory cells. Loss of the corneal endothelial cells and Descemet's membrane could be associated with the CP-induced corneal edema and hydrops which could lead to long term term pathological conditions. Although exposure to 20% CP for 1 min caused more eyelid swelling, ulceration, and hyphema, similar effects were observed with all CP exposures. These novel findings following CP ocular exposure in a mouse model outline the corneal histopathologic changes that associate with the continuing ocular clinical effects. The data are useful in designing further studies to identify and correlate the clinical and biological markers of CP ocular injury progression with acute and long-term toxic effects on cornea and other ocular tissues. We take a crucial step towards CP ocular injury model development and in pathophysiological studies to identify molecular targets for therapeutic interventions.

Long-Standing Corneal Edema and Endothelial Decompensation due to Ecballium elaterium

PURPOSE

The purpose of this study was to report the most severe documented ocular injury caused by Ecballium elaterium , an invasive and toxic herb characterized by an explosive seed dispersal.

METHODS

A 55-year-old man presented to the emergency department several hours after direct exposure to the contents of E. elaterium to his left eye. Clinical examinations, investigations, and imaging findings are reported.

RESULTS

Medical and ocular histories were unremarkable. On presentation, the patient exhibited markedly decreased visual acuity, severe periorbital edema, conjunctival chemosis, and corneal edema. Although other signs gradually improved, corneal edema worsened despite rapid initiation of systemic and topical steroids and normal intraocular pressure. After 4 months of follow-up, the cornea cleared and visual acuity returned to normal; however, a significant decrease in endothelial cell count was observed.

CONCLUSIONS

Ecballium elaterium may cause a severe corneal chemical burn, with subsequent long-standing corneal edema and endothelial decompensation. Specular microscopy is a modality of great importance in these cases.

A Case of Serious Eye Injury Caused by a Mistaken Injection of Methylrosaniline Chloride During Vitreous Surgery

This case involved a 75-year-old female with left-eye epiretinal membrane (ERM) and cataract who developed serious eye disorders during vitreous surgery due to methylrosaniline chloride (MRC) being mistakenly injected and applied to the retina instead of Brilliant Blue G during internal limiting membrane staining. Once realized, MRC was washed out with intraocular infusion solution, and ERM surgery was successfully completed. Postoperatively, a Descemet's fold and corneal edema, marked reduction in corneal endothelial cell density, and inner retina damage and visual field defect extending from the macula toward the temporal side were observed. MRC was found highly toxic to eye tissues. [Ophthalmic Surg Lasers Imaging Retina. 2017;48:1010-1015.].

Amantadine Use as a Risk Factor for Corneal Edema: A Nationwide Cohort Study in Taiwan

PURPOSE

To evaluate the association between amantadine use and corneal toxicity in a nationwide population.

DESIGN

Retrospective cohort study of nationwide population-based administrative database.

METHODS

This study analyzed data in the Taiwan Longitudinal Insurance Database for a group of 8195 patients diagnosed with Parkinson disease during a 15-year period (January 1, 1996 to December 31, 2010). A control group of 8195 patients without Parkinson disease was randomly matched with the Parkinson group by age, sex, and comorbidity index. The Kaplan-Meier method was used to calculate the cumulative incidence of corneal edema. Incident rate ratios and Cox proportional hazard regressions were estimated to compare the risk of corneal edema. The same methods were then used to compare the risk between patients with and without amantadine treatment.

RESULTS

The incidence of corneal edema in the Parkinson group (123 patients; 1.50%) was significantly higher than that in the control group (82 patients; 1.0%) (P = .004). The incidence ratio for corneal edema in the Parkinson group vs the controls was 5.77. When the Parkinson group was further subgrouped by use and non-use of amantadine, the hazard ratio for corneal edema was 1.79 times higher in the amantadine subgroup. Analyses of the amantadine subgroup by cumulative dose revealed that the 30-day hazard ratio for corneal edema was 2.05 higher in patients given moderate doses (2000-4000 mg) of amantadine and 2.84 times higher in the subgroup of patients given high doses (>4000 mg).

CONCLUSIONS

Amantadine increases the risk of corneal edema in a dose-dependent manner.

Persistent Corneal Edema Associated With Subconjunctival 5-fluorouracil in an Infant With Primary Congenital Glaucoma

A 3-month-old boy with primary congenital glaucoma developed a transient corneal endothelial opacity after needle bleb revision with adjunctive 5-fluorouracil. This case presents a rare toxicity that, although transient, is concerning due to the potential of amblyopia. The authors review prior cases of corneal opacity associated with 5-fluorouracil. [J Pediatr Ophthalmol Strabismus. 2016;53:e54-e57.].

Corneal toxicity after Ozurdex(®) migration into anterior chamber

OBJECTIVE

To describe a case of corneal toxicity after migration of a dexamethasone implant into the anterior chamber.

CASE REPORT

A 62-year-old man with aphakia and a history of vitrectomy received a dexamethasone implant for a refractory Irvine-Gass syndrome. Thirty days later, the implant migrated into the anterior chamber causing endothelial contact with secondary corneal oedema that justified the removal of the implant without resolution of the oedema.

DISCUSSION

Clinical tolerability to dislocated implant is poor in cases with pre-existing corneal oedema, and because of this, it must be removed early. In cases of aphakia and vitrectomy, the increased risk of Ozurdex(®) dislocation justifies performing a prior endothelial count.

Amines as occupational hazards for visual disturbance

Various amines, such as triethylamine and N,N-dimethylethylamine, have been reported to cause glaucopsia in workers employed in epoxy, foundry, and polyurethane foam industries. This symptom has been related to corneal edema and vesicular collection of fluid within the corneal subepithelial cells. Exposure to amine vapors for 30 min to several hours leads to blurring of vision, a blue-grey appearance of objects, and halos around lights, that are probably reversible. Concentration-effect relationships have been established. The visual disturbance is considered a nuisance, as it could cause onsite accidents, impair work efficiency, and create difficulties in driving back home. Occupational exposure limits have been established for some amines, but there is shortage of criteria. Volatility factors, such as vapor pressure, should be considered in industrial settings to prevent human ocular risks, while trying to reduce levels of hazardous amines in the atmosphere.

[Corneal toxicity due to amantadine]

CASE REPORT

A 64 year-old female with Parkinson disease treated with amantadine for two years who suddenly suffered bilateral corneal oedema. It was initially treated as herpetic endotheliitis without improvement as we lacked information on her chronic treatment. The corneal oedema finally resolved after withdrawing the drug.

DISCUSSION

Amantadine hydrochloride may produce endothelial dysfunction. Once the amantadine treatment is stopped, the corneal oedema may be reversible but endothelial density remains low. An ophthalmologist examination should be performed before the initiation of amantadine treatment in order to establish a risk: benefit ratio, especially in those patients with low endothelial density or any endothelial anomaly.

Frog saliva-induced toxic keratopathy: a case report

Corneal toxicity due to exposure to many chemicals and medications have been described in the literature. We present a case of toxic keratopathy by corneal exposure to salivary secretion of a frog. A 40-year-old male patient reported a sudden splash of frog saliva in his right eye while he was examining it at a close distance. Corneal punctate epitheliopathy and stromal oedema and Descemet folds were the initial clinical findings, which completely recovered on the 2nd control day of topical dexamethasone and ofloxacin treatment. We aimed to show the toxic effects of animal-derived secretions on the cornea as a rare cause of toxic keratopathy.

Bilateral corneal edema secondary to amantadine in the pediatric population: a case report

PURPOSE

To report a case of amantadine induced corneal edema in a pediatric patient.

METHODS

A comprehensive ophthalmologic evaluation was performed to a 16-year-old female patient who presented with bilateral, painless loss of vision and corneal edema.

RESULTS

Review of the patient's medical information revealed the use of amantadine to alleviate extrapyramidal side effects secondary to psychiatric medications. Complete resolution of bilateral corneal edema was achieved one month after cessation of amantadine therapy.

CONCLUSION

Amantadine induced corneal edema should be considered in the differential diagnosis of bilateral corneal edema in all age groups. Review of the toxic side effects of systemic medications should be performed in every patient who presents with bilateral corneal edema.

Amantadine-associated corneal edema treated with descemet's stripping automated endothelial keratoplasty

The authors report the successful use of Descemet's stripping automated endothelial keratoplasty (DSAEK) to treat a 45-year-old woman with amantadine-associated corneal edema. Discontinuation of the medication and treatment with corticosteroids did not result in resolution of the edema. The patient underwent sequential phakic DSAEK in both eyes with significant anatomic, visual, and functional improvement. Histopathologic analysis of Descemet's membrane by light microscopy revealed a paucity of endothelial cells. This case highlights the importance of considering amantadine toxicity in the differential diagnosis of corneal edema without an identifiable ocular cause and suggests the utility of DSAEK in the treatment of this rare condition.

Amantadine-associated corneal edema potentially irreversible even after cessation of the medication

PURPOSE

To describe the clinical features of 3 patients with amantadine-associated corneal edema, including the histopathologic findings from 1 patient who underwent corneal transplantation for irreversible corneal edema.

DESIGN

Interventional case series.

PARTICIPANTS

Three patients who sought treatment at the authors' institution with abrupt-onset, bilateral, diffuse corneal edema associated with systemic amantadine use.

METHODS

Retrospective chart review.

MAIN OUTCOME MEASURES

Visual acuity, corneal thickness, slit-lamp observations, and histopathologic findings.

RESULTS

The duration of use of amantadine ranged from 2 months to 6 years before onset of corneal edema. Discontinuation of amantadine resulted in resolution of corneal edema in both eyes of 2 patients. A third patient underwent a full-thickness corneal transplantation, and subsequently, edema developed in the grafted cornea. Cessation of amantadine therapy in this patient resulted in resolution of corneal edema in both eyes, but the ungrafted corneal eventually decompensated and became edematous, requiring corneal transplantation. Histopathologic analysis of the cornea buttons showed significant loss of endothelial cells.

CONCLUSIONS

Amantadine can cause corneal edema that begins a few months to several years after institution of therapy, and the edema can occur even in a corneal graft. Prolonged corneal edema in the setting of amantadine use can be irreversible. In cases of corneal edema without an obvious causative disease, the systemic medication list of the patient must be reviewed, and amantadine must be considered as a possible cause.

Comparison of triamcinolone acetonide, 11-deoxycortisol and other lipid formulae for the visualization of vitreous body in the anterior chamber after posterior capsule rupture in animal models

PURPOSE

The efficacy and toxicity of triamcinolone acetonide and other lipid formulae--calcium palmitate, cholesterol and 11-deoxycortisol--in the visualization of the prolapsed vitreous body in the anterior chamber after posterior capsule rupture were investigated in animal models.

METHODS

In porcine eyes, a suspension of calcium palmitate, cholesterol, triamcinolone acetonide and 11-deoxycortisol was injected into the anterior chamber after intentionally creating posterior capsule rupture. Following gentle irrigation and aspiration, the vitreous body prolapsed in the anterior chamber was removed using an anterior vitrectomy cutter. In phakic rabbit eyes, the side-effects of the reagents were assessed for biomicroscopic appearance, intraocular pressure (IOP) and corneal histology.

RESULTS

The suspension of calcium palmitate, cholesterol, triamcinolone acetonide and 11-deoxycortisol was effective in the visualization of the vitreous body prolapsed in the anterior chamber after posterior capsule rupture. When cholesterol and calcium palmitate were injected into the anterior chamber, they remained there; this induced a significant increase in IOP and corneal oedema. In contrast, most of the triamcinolone acetonide and 11-deoxycortisol that was injected into the anterior chamber had disappeared a day after the injection without affecting IOP or corneal endothelial density. When injected into the intravitreous cavity, triamcinolone led to a significant increase in IOP 2 and 4 weeks after the injection. However, calcium palmitate, cholesterol and 11-deoxycortisol injected into the vitreous cavity had no effect on IOP at 4 weeks.

CONCLUSION

The suspension of triamcinolone acetonide and 11-deoxycortisol was effective in visualizing the vitreous body prolapsed in the anterior chamber after posterior capsule rupture. However, the amount of the reagent must be kept to a minimum to prevent the potential risk of ocular toxicities and postoperative late-onset ocular hypertension.

Postmarketing Surveillance of Corneal Edema, Fuchs Dystrophy, and Amantadine Use in the Veterans Health Administration

PURPOSE

To determine the proportion of patients who were dispensed amantadine and diagnosed with corneal edema or Fuchs dystrophy within specified time frames.

METHODS

Postmarketing surveillance study. The national Veterans Health Administration pharmacy and clinical databases were used to identify a cohort of veterans without a prior history of corneal edema, Fuchs dystrophy, or a prescription for amantadine. During fiscal years 2005-2006, 2 databases were used to identify patients with new diagnoses of corneal disease and new prescriptions for amantadine. Patients from each were cross-referenced. The outcome measure was concurrent diagnosis of corneal edema or Fuchs dystrophy and new prescription for amantadine within specified intervals.

RESULTS

Thirty-six (0.27%) patients among the 13,137 who were dispensed amantadine were diagnosed with corneal edema or Fuchs dystrophy within the 2-year study period. The relative risk of corneal edema for a person prescribed amantadine was 1.7 (95% confidence interval: 1.1-2.8). In 12 (0.09%) patients, the corneal diagnoses were recorded within a month of being prescribed amantadine.

CONCLUSIONS

Retrospective examination of a large national medical database revealed that amantadine was temporally associated with a small proportion of patients diagnosed with corneal edema or Fuchs dystrophy. Although additional studies are needed to confirm the risk of corneal edema with amantadine, the development of corneal edema in persons prescribed amantadine warrants clinical attention. In such a situation, physicians may consider stopping amantadine to see if the edema subsides.

Euphorbia lactea sap keratouveitis: case report and review of the literature

PURPOSE

To describe a case of Euphorbia lactea sap keratouveitis and to review all reported cases of ocular toxicity caused by Euphorbia species.

METHODS

Case report and review of literature.

RESULTS

A 79-year-old woman presented 34 hours after she felt some sap of an E. lactea plant spray into her right eye. Visual acuity was counting fingers at 1 m. Examination revealed ciliary injection, 90% corneal epithelial defect, marked stromal edema with Descemet folds, and anterior-chamber flare with a 1-mm hypopyon. There was no vitreitis, and funduscopy was unremarkable. No foreign body was seen on B scan ultrasound or computed tomography scan of the orbits. Corneal scraping excluded bacterial and herpetic keratitis. Intensive topical antibiotic therapy was started with cephalothin 5% and gentamicin 0.9%, and the pupil was dilated with atropine. Topical steroids were started once the epithelial defect had healed. Examination 11 weeks after the injury revealed minimal subepithelial corneal haze and marked improvement in visual acuity.

CONCLUSIONS

To the best of our knowledge, this is only the third reported case of E. lactea sap keratouveitis. The clinical course of E. lactea sap keratouveitis is compared with that reported for other Euphorbia species.

Œdème de cornée et AINS systémiques

INTRODUCTION

We report a case of a transient corneal edema related to systemic NSAID treatment.

OBSERVATION

A 48-year-old woman treated with a systemic NSAID [piroxicam B-cyclodextrin (Brexin) and naproxen (Apranax)] presented with a corneal edema and a transient decrease in visual acuity for a period of 24 h. No ocular etiology was found to explain this corneal edema. Another treatment with Apranax was follow by another corneal edema.

CONCLUSION

Corneal edema could be related to systemic NSAID treatment.

Long-term recovery of the human corneal endothelium after toxic injury by benzalkonium chloride

INTRODUCTION

The inadvertent intra-ocular administration of benzalkonium chloride-preserved hydroxypropyl methylcellulose during cataract surgery at another hospital in 1999 resulted in toxic corneal endothelial injury and profound postoperative corneal oedema as a result of endothelial decompensation. The long-term effect of this adverse event was assessed.

METHODS

All 19 patients were invited to return for examination including corneal endothelial specular microscopy and pachymetry seven years after the incident. Results were compared with data from one year after the incident.

RESULTS

Five patients attended for examination, one had received a penetrating keratoplasty and was, therefore, excluded. Ten patients had died and four had moved out of the region and were unable to attend. All four study patients were pain free and achieved 6/12 or better. Mean central corneal thickness reduced by 13% from 652.6 microm at one year to 563.4 microm. Mean central corneal endothelial cell density (n = 3) increased 28% from 663.7 cells/mm(2) at one year to 835.7 cells/mm(2) (p<0.05).

CONCLUSIONS

After toxic injury, corneal endothelial function may have a remarkable capacity for recovery even after the first postoperative year. The rise in central endothelial cell density may represent cell migration from less affected areas or cellular proliferation. Should this unfortunate event recur, clinicians may expect continued recovery beyond one year.

Cutaneous and ocular adverse reactions in a dog following meloxicam administration

The present report addresses the development of cutaneous and ocular reactions possibly related to meloxicam administration in a dog. Based on clinical signs and absence of laboratory data compatible with the other differential diagnoses considered, the possibility of an adverse drug reaction (ADR) due to meloxicam was considered. Skin biopsy revealed haemorrhage of the superficial and deep dermis, associated with hyperplasia of endothelial cells and epidermal sloughing. Vasculitis in the deep dermis was also noted. Such lesions were considered compatible with an ADR. Although the owner was not aware of any previous allergic reaction to drugs, the animal had a clinical history of atopic dermatitis. Meloxicam is a nonsteroid anti-inflammatory drug (NSAID) in the oxicam family, indicated for the control of inflammation and pain in acute and chronic musculoskeletal disorders in dogs. Although meloxicam is usually well tolerated, the present clinical case represents an alert to practitioners about the potential role of NSAIDS in ADRs in dogs with a history of allergic cutaneous diseases.

Corneal Edema and Permanent Blue Discoloration of a Silicone Intraocular Lens by Methylene Blue

BACKGROUND AND OBJECTIVE

To report a silicone intraocular lens (IOL) stained blue by inadvertent intraoperative use of methylene blue instead of trypan blue and the results of experimental staining of various lens materials with different concentrations of the same dye.

MATERIALS AND METHODS

A "blue dye" was used to enhance visualization during capsulorhexis in a patient undergoing phacoemulsification with implantation of a three-piece silicone lens. Postoperatively, the patient presented with corneal edema and a discolored IOL. Various IOL materials were experimentally stained using methylene blue. Sixteen lenses (4 silicone, 4 hydrophobic acrylic, 4 hydrophilic acrylic, and 4 polymethylmethacrylate) were immersed in 0.5 mL of methylene blue at concentrations of 1%, 0.1%, 0.01%, and 0.001%. These lenses were grossly and microscopically evaluated for discoloration 6 and 24 hours after immersion.

RESULTS

The corneal edema resolved within 1 month after the initial surgical procedure. After explantation, gross and microscopic analyses of the explanted silicone lens revealed that its surface and internal substance had been permanently stained blue. In the experimental study, all of the lenses except the polymethylmethacrylate lenses were permanently stained by methylene blue. The hydrophilic acrylic lenses showed the most intense blue staining in all dye concentrations.

CONCLUSIONS

This is the first clinicopathological report of IOL discoloration due to intraocular use of methylene blue. This and other tissue dyes may be commonly found among surgical supplies in the operating room and due diligence is necessary to avoid mistaking these dyes for those commonly used during ocular surgery.

Outbreak of toxic anterior segment syndrome associated with glutaraldehyde after cataract surgery

PURPOSE

To present clinical findings of a cluster of cases of toxic anterior segment syndrome (TASS) after uneventful phacoemulsification cataract surgery.

SETTING

Department of Ophthalmology, Akdeniz University, Antalya, Turkey.

METHODS

Six eyes of 6 patients developed TASS after uneventful phacoemulsification cataract surgery with implantation of a 3-piece acrylic IOL performed by 2 ophthalmologists on the same day. Clinical findings included corneal edema, Descemet's membrane folds, anterior chamber reaction, fibrin formation, and irregular, dilated, and unreactive pupils.

RESULTS

Glutaraldehyde 2% solution was used inadvertently by the operating room staff who cleaned and sterilized reusable ocular instruments before autoclaving. None of the affected corneas improved. Additional surgical procedures were required and included penetrating keratoplasty, trabeculectomy, and glaucoma tube implantation.

CONCLUSIONS

Glutaraldehyde in concentrations generally used for cold sterilization is highly toxic to the corneal endothelium. The operating room staff involved in sterilizing instruments should be well educated about and careful to follow the protocols to properly clean and sterilize reusable ocular instruments.

Severe Corneal Toxicity After Topical Fluoroquinolone Therapy

PURPOSE

To describe 2 cases of sterile corneal ulcers that persisted after several weeks of therapy with topical moxifloxacin 0.5% but that resolved when antibiotic therapy was changed.

METHODS

Small case series.

RESULTS

Both cases presented here describe corneal ulcers that persisted and showed signs of worsening during weeks of frequent topical dosing with moxifloxacin. Descemet folds and an atypically large amount of stromal edema were present in both cases, and there appeared to be possible endothelial dysfunction as well. There was no sign of bacterial, viral, or fungal infection in either case. In both cases, healing began a few days after moxifloxacin was discontinued, and topical gatifloxacin and corticosteroids were initiated.

CONCLUSION

These cases suggest that moxifloxacin may interfere with the healing of corneal ulcers.

Severe Toxic Effect of Methylene Blue 1% on Iris Epithelium and Corneal Endothelium

PURPOSE

To report a case of corneal endothelial decompensation and iris pigment dispersion following the inadvertent use of methylene blue 1% for capsular staining during cataract surgery.

DESIGN

Case report.

METHODS

During an otherwise routine phacoemulsification cataract surgery, inadvertent anterior capsule staining with methylene blue 1% instead of trypan blue 0.025% was performed. Copious irrigation of the anterior chamber with balanced salt solution was initiated upon identification of the wrong dye. The operation was completed with minimal ultrasound energy without complications.

RESULTS

Iris discoloration and severe corneal edema developed in the early postoperative period, resulting in severe visual loss. The patient developed bullous keratopathy and underwent penetrating keratoplasty 16 months later.

CONCLUSIONS

In vivo intracameral injection of methylene blue 1% induces extreme cytotoxicity, primarily on the corneal endothelium and iris epithelium.

Acute onset of halos and glare: Bilateral corneal epithelial edema with cystic eruptions—atypical presentation of amiodarone keratopathy

BACKGROUND

Amiodarone (Cordarone; Wyeth, Ayerst, New York) is a potassium channel blocking antiarrythmal medication indicated for recurrent ventricular fibrillation and recurrent hemodynamically unstable ventricular tachycardia. Chemically, it is classified as an iodinated benzofuran derivate antiarrythmal drug not chemically related to any other available antiarrhythmic drug. Documented side effects of amiodarone include neurologic, gastrointestinal, dermatologic, cardiovascular, and ophthalmic. The ophthalmic abnormalities include optic neuropathy, optic neuritis, papilledema, corneal deposits, photosensitivity, lens opacities, and macular degeneration. Corneal microdeposits are seen in virtually all patients who receive amiodarone for more than 6 months. Corneal microdeposits result secondary to the secretion of amiodarone by the lacrimal gland with accumulation on, and absorption by, the corneal epithelium. Approximately 10% of these patients become symptomatic with glare and halos; however, that alone is usually not enough to precipitate intervention.

CASE REPORT

A 69-year-old woman presented to our office with a 2-week history of halos and glare in both eyes (OU). Her ocular history was significant for occasional contact lens wear. Her systemic history was significant for atrial fibrillation, for which she was taking amiodarone daily for the last 6 years. Six weeks before the onset of her chief complaint, her daily amiodarone dosage was increased from 100 mg to 300 mg. Ophthalmic examination found decreased visual acuities OU, amiodarone keratopathy (subepithelial verticillata), and diffuse corneal epithelial edema with diffuse sodium fluorescein staining OU. The corneal compromise was treated in 2 ways: the source medication was discontinued, and the ocular signs were medicated with a prophylactic topical antibiotic along with supportive preparations (tears/lubricants) and monitored over 2 weeks until full elimination of the pathologic signs and their symptoms. Even after complete resolution of the acute keratitis, the infiltrative keratopathy persisted along with the initial complaints of halos and glare. The supportive treatments were maintained over the course of 2 months until full recovery.

CONCLUSION

By exclusion, it was determined that the subepithelial depositions and cystic formations were secondary to an acute amiodarone dosage increase by a new practitioner. Prompt communication resulted in the physician discontinuing that medicine.

Toxic anterior segment syndrome and possible association with ointment in the anterior chamber following cataract surgery

PURPOSE

To report clinical and laboratory findings of 8 cases of toxic anterior segment syndrome (TASS) related to an oily substance in the anterior chamber of patients following cataract surgery with intraocular lens (IOL) implantation.

SETTING

John Moran Eye Center, University of Utah, Salt Lake City, Utah, USA.

METHODS

Eight patients had uneventful phacoemulsification by the same surgeon via clear corneal incisions with implantation of the same 3-piece silicone IOL design. Postoperative medications included antibiotic/steroid ointment and pilocarpine gel; each eye was firmly patched at the end of the procedure. On the first postoperative day, some patients presented with diffuse corneal edema, increased intraocular pressure, and an oily film-like material within the anterior chamber coating the corneal endothelium. The others presented with an oily bubble floating inside the anterior chamber, which was later seen coating the IOL. Additional surgical procedures required included penetrating keratoplasty, IOL explantation, and trabeculectomy. Two corneal buttons were analyzed histopathologically. Two explanted IOLs had gross and light microscopic analyses (as well as surface analyses of 1 of them), and 4 other explanted IOLs had gas chromatography-mass spectrometry.

RESULTS

Pathological examination of the corneas showed variable thinning of the epithelium with edema. The stroma was diffusely thickened and the endothelial cell layer was absent. Evaluation of the explanted IOLs confirmed the presence of an oily substance coating large areas of their anterior and posterior optic surfaces. Gas chromatography-mass spectrometry of the lens extracts identified a mixed chain hydrocarbon compound that was also found in the gas chromatography-mass spectrometry analyses of the ointment used postoperatively.

CONCLUSIONS

The results indicate that the ointment gained access to the eye, causing the postoperative complications described. These cases highlight the importance of appropriate wound construction and integrity, as well as the risks of tight eye patching following placement of ointment.

Comparison of Corneal Thickness After the Instillation of Topical Anesthetics

PURPOSE

To compare changes in human corneal thickness after the instillation of proparacaine with those after oxybuprocaine instillation with time over a period of 10 minutes.

METHODS

Eighteen healthy young participants were recruited. Proparacaine was used in the right eye and oxybuprocaine in the left. Right and left baseline corneal thicknesses were measured every 30 seconds for 10 minutes using a noncontact specular microscope by 1 observer. Baseline corneal thickness was defined as the average of all values taken over 10 minutes. Changes in corneal thickness were measured every 20 seconds for 10 minutes after the administration of 1 drop of 0.5% proparacaine onto the right cornea and 1 drop of 0.4% oxybuprocaine onto the left cornea.

RESULTS

Mean baseline right cornea thickness was 531 +/- 45 microm, and that of the left cornea was 531 +/- 42 microm. The corneal thickness after proparacaine increased by 8.6 microm ( approximately 4.5-12.6 microm, 95% CI) and then returned to baseline within 80 seconds. Corneal thickness after applying oxybuprocaine increased by 7.7 microm (3.6-11.2 microm, 95% CI) and then returned to baseline within 80 seconds. There was a second transient increase about 5 minutes later after proparacaine instillation but no additional transient increase after oxybuprocaine instillation.

CONCLUSION

Oxybuprocaine is similar to proparacaine in terms of the severity of its effect on corneal thickness. Corneal thickness instability may occur for 5 minutes after proparacaine administration. Changes in corneal thickness after topical anesthetic instillation should be considered when performing measurements for refractive surgery or central corneal thickness in glaucoma patients.

Corneal Keratocyte Apoptosis Following Topical Intraoperative Mitomycin C in Rabbits

PURPOSE

To determine the soaking duration and concentration effect of mitomycin C (MMC) on the corneal keratocyte following single intraoperative application.

METHODS

Two hundred ten pigmented rabbit eyes underwent mechanical epithelium debridement of the central 10-mm comea followed by soaking of six different solutions: MMC1A: 0.01% MMC x 1 minute; MMC1B: 0.01% MMC x 2 minutes; MMC2A: 0.02% MMC x 1 minute; MMC2B: 0.02% MMC x 2 minutes; BSS1: balanced salt solution (BSS) x 1 minute; and BSS2: BSS x 2 minutes. Thirty-five eyes were allocated into each group. Changes of the central comeal thickness, corneal clarity score, and keratocyte apoptosis were examined on days 0, 1, 2, 3, 5, 7, and 14.

RESULTS

A significant increase of central corneal thickness and corneal clarity score was noted in all MMC treated groups. The central corneal thickness recovered to its baseline level whereas the corneal clarity score remained increased at 2 weeks. The changes were more significant in MMC2 than in MMC1 corneas. However, changes of central corneal thickness and corneal clarity score were more significant in MMC1B than in MMC1A, whereas no difference was noted between MMC2A and MMC2B. Significantly higher stromal keratocyte loss and keratocyte apoptosis, from superficial to deep corneal stroma, was noted in MMC1 and MMC2 groups up to 14 days postoperatively, in a soaking duration and dose-dependent manner.

CONCLUSIONS

Single application of MMC on the corneal surface caused soaking concentration and duration dependent corneal edema and keratocyte apoptosis in this rabbit model.

Corneal toxicity and inflammation secondary to retained perfluorodecalin

PURPOSE

To describe a case with bullous keratopathy and anterior segment inflammation associated with heavy liquids.

DESIGN

Observational case report.

METHODS

Review of clinical and histopathologic changes.

RESULTS

A 65-year-old patient underwent a pars plana vitrectomy for a rhegmatogenous retinal detachment. Perfluorodecalin was used as a temporary retinal tamponade. After surgery, bubbles of heavy liquid were noted in the anterior chamber. Fifteen months later, severe corneal edema developed, associated with corneal vascularization and keratic precipitates. Removal of heavy liquid through a paracentesis was attempted but the cornea remained edematous, and a penetrating keratoplasty was performed. In the histopathologic examination inflammatory changes from retention of perfluorodecalin were observed. There was a decompensated cornea with florid bullous keratopathy, inflammatory infiltration with vascularization, and deposition of perfluorodecalin within keratocytes and perivascular macrophages.

CONCLUSION

Presence of heavy liquids in the anterior chamber may be associated with an intense inflammatory response and corneal decompensation.

Calotropis procera (ushaar) keratitis

PURPOSE

To report a case of permanent endothelial cell injury after intracorneal penetration of milky latex from Calotropis procera (ushaar).

DESIGN

Interventional case report.

METHODS

A 40-year-old patient developed painless corneal edema despite minimal epithelial injury after exposure to ushaar latex.

RESULTS

Confocal and specular microscopy confirmed permanent endothelial cell loss with morphologic alteration after intracorneal penetration of ushaar latex. Corneal edema resolved completely after 2 weeks, although reduced endothelial cell count and abnormal morphology persisted.

CONCLUSION

Ushaar latex is capable of penetrating the corneal stroma and inducing permanent loss of endothelial cells. Corneal edema resolves if sufficient endothelial cell viability is still present after resolution of ushaar keratitis.

Reversible Amantadine-Induced Corneal Edema in an Adolescent

PURPOSE

To document reversible corneal edema caused by amantadine in a pediatric patient.

METHODS

A 14-year-old boy with a neurologic tremor was referred for bilateral visual loss. Our examination disclosed bilateral corneal edema without ocular inflammation. Pachymetry confirmed significantly increased corneal thickness above 900 microm.

RESULTS

Review of the patient's medical information revealed recent institution of amantadine as a means to control the patient's tremor. On cessation of this agent, rapid resolution of corneal edema and recovery of visual acuity occurred. Repeat pachymetry measurement revealed normal corneal thickness.

CONCLUSION

In cases of corneal edema and in the absence of any identifiable ocular causes, a review of toxic effects of systemic medication should be undertaken. Amantadine can cause corneal decompensation and needs to be considered as part of the differential diagnosis of corneal edema.

Permanent Corneal Edema Resulting From the Treatment of PTK Corneal Haze With Mitomycin

A 39-year-old man underwent phototherapeutic keratectomy via excimer laser for recurrent corneal erosions secondary to basement membrane dystrophy with the subsequent development of irregular astigmatism and central stromal opacity. The cornea was scraped and treated with 0.02% mitomycin C using a total of 14 drops over a period of 6 days. Corneal edema developed as a consequence of low endothelial cell count with dysfunctional cells. A corneal transplant restored acuity of 20/20 with binocular vision. It is believed that the underlying endothelium was exposed to toxic doses of mitomycin C sufficient to damage and destroy vital cells. The author reports this case not to criticize the use of mitomycin C in visually disabling post-phototherapeutic keratectomy or photorefractive keratectomy haze but to apprize colleagues of a potential pitfall. The author believes that the use of mitomycin C as a 1-time application at the end of surgery is a safe and valuable adjunct to recover vision when no other is known. However, continued topical application of mitomycin C to the central cornea, in the face of an epithelial defect or an epithelium with inadequate barrier function, increases the risk of endothelial damage.

Early corneal edema following topical application of mitomycin-C

PURPOSE

To determine the effect of mitomycin-C (MMC) on the cornea after a single intraoperative application.

SETTING

Department of Ophthalmology, Far Eastern Memorial Hospital, Ban-Chiao, Taipei, Taiwan.

METHODS

Mechanical epithelium debridement of the central 10.0 mm of the cornea was performed in 63 pigmented rabbits. One group of corneas (MMC1, n = 42) was soaked with MMC 0.01% solution for 2 minutes; the second group (MMC2, n = 42) was soaked with MMC 0.02% solution for 2 minutes. Control corneas (n = 42) were soaked with balanced salt solution for 2 minutes. Changes in the central corneal thickness, clarity, epithelial defect size, endothelial cell density, and endothelial apoptosis in the 3 groups were examined on days 0, 1, 2, 3, 5, 7, and 14.

RESULTS

There was a dose-dependent increase in corneal thickness, decrease in corneal clarity, and increase in endothelial apoptosis after a single intraoperative application of MMC. The endothelium was significantly swollen and became pleomorphic and polymegethic with a concomitant decrease in endothelial cell density, also in a dose-dependent manner.

CONCLUSIONS

A single application of MMC on the corneal surface caused dose-dependent corneal edema and endothelial apoptosis in the rabbit model. Further clinical study of human eyes is warranted.

Corneal endothelial safety of intracameral preservative-free 1% xylocaine

PURPOSE

To evaluate the effect of intracameral preservative-free 1% xylocaine on the corneal endothelium as an adjuvant to topical anaesthesia during phacoemulsification and Acrysof foldable IOL implantation.

MATERIAL & METHODS

This is a prospective, controlled, randomised, double-masked study. 106 patients with soft to moderately dense (Grade 1-3) senile cataract and corneal endothelial cell density of >1500/mm2 were randomised to the xylocaine group (n=53) and control group(n=53). Central endothelial specular microscopy and ultrasound corneal pachymetry were performed preoperatively. On the first postoperative day the eyes were evaluated for corneal oedema and Descemet's folds. Ultrasound corneal pachymetry was performed at 1, 3 and 12 months. Specular microscopy was performed at 3 and 12 months. Cell loss was expressed as a percentage of preoperative cell density. Six patients could not complete one year follow-up. Chi-square and paired t test (2 tail) statistical tests were applied for analysis.

RESULTS

Four (7.54%) patients in the xylocaine group and 5 (9.43%) in the control group had a few Descemet's folds associated with mild central stromal oedema. Corneal thickness increased from 549.3micro +/- 37.2micro to 555.5micro +/- 36.5micro in the xylocaine group and from 553.1micro +/- 36.2micro to 559.3micro +/- 40.5micro in the control group at the one-month postoperative visit. Thickness returned to the preoperative level in xylocaine group 549.6micro +/- 34.5micro and control group 554.7micro +/- 41.1micro at three months. (P=0.484) The percentage of cell loss was 4.47 +/- 2.53% in the xylocaine group and 4.49 +/- 3.09% in the control group at one year. (P=0.97)

CONCLUSION

Intracameral preservative-free 1% xylocaine does not appear to affect corneal endothelium adversely during phacoemulsification.

The effect of photodynamic therapy with rose bengal on posterior capsule opacification in rabbit eyes

We investigated the in vivo effect of photodynamic therapy (PDT) using rose bengal on the development of posterior capsule opacification (PCO). Endocapsular phacoemulsification was performed on white rabbits, which were divided into 4 groups: control group; group 1, treated with visible light only; group 2, treated with rose bengal only, and group 3, treated with PDT. In the case of the PDT group, rose bengal dissolved in sodium hyaluronate was injected into the empty capsular bag and treated with visible light. Three months after surgery, the rabbits were sacrificed and the eyeballs enucleated. The obstruction rate of visible light caused by PCO was measured with an optical powermeter. The mean obstruction rate was 30.6% in the control group, 28.3% in group 1, 19.3% in group 2, and 14.3% in group 3. Group 3 showed a statistically significant decrease in PCO compared with the control group and group 1 (p = 0.0014). Our results suggest that PDT using rose bengal effectively decreased PCO in rabbit eyes.

Risks and benefits of oral contraceptive pills

In the more than 40 years since the combined oral contraceptive pill was first marketed, much information has been obtained as to its risks. Considerably less publicity has been given to the balancing benefits that have also emerged. There has been an increasing realization that the risks are focused in those women with recognised risk factors, meaning that the remainder can use the product with increasing reassurance. The doses of both hormones have also been lowered considerably since the early years. Thus, it can be a rational decision by a fully informed woman to use this form of contraception.

The effects of bupivacaine and lidocaine on the corneal endothelium when applied into the anterior chamber at the concentrations supplied commercially

PURPOSE

To investigate the direct toxic effects of bupivacaine HCl 0.5% and lidocaine HCl 2%, two commonly used injectable local anesthetic agents, on the corneal endothelium when applied intracamerally.

METHODS

Two groups were formed, each consisting of 12 pigmented rabbits, and 0.2 ml of the anesthetic agent were injected intracamerally into the right eyes. The central corneal thicknesses and corneal clarities were evaluated preoperatively and at 3, 6, 9, 12 h and 1, 3, 7 days postoperatively. While the central corneal thicknesses were evaluated by ultrasonic pachymetry, the corneal opacification scored between 0 and 3 was assessed by biomicroscopic examination and photographs.

RESULTS

Both bupivacaine and lidocaine caused corneal thickening in the 3- to 12-hour measurements. In addition, there was significant corneal opacification in both groups in the 3-hour and 3-day measurements. The corneal thickening and corneal opacification determined during 3- and 6-hour measurements in the eyes which received intracameral bupivacaine were significantly higher than those determined in the lidocaine-injected group. In both groups, the corneal thickness and corneal clarity scores returned to the preoperative values on the 1st and 7th days, respectively.

CONCLUSIONS

When applied into the anterior chamber at the concentrations supplied commercially, both bupivacaine and lidocaine cause statistically significant corneal thickening and clinically significant corneal opacification. It should be noted that the injection of these agents into the anterior chamber during the operation at the concentrations supplied commercially may be a potential risk factor for endothelial injury.

Effects of enzymatic sterilization detergents on the corneal endothelium

OBJECTIVE

To evaluate the potential of enzymatic detergents to cause endothelial damage and anterior segment inflammation.

METHODS

Paired rabbit corneas were mounted in an in vitro specular microscope. Endothelia were perfused either with the sterile irrigating solution BSS Plus (Alcon Laboratories Inc, Ft Worth, Tex) (control) or 0.1%, 0.4%, or 1.0% Medline Enzymatic Detergent (Medline Industries Inc, Mundelein, Ill) in BSS Plus. Swelling rates were determined by regression analysis. Human endothelia were perfused using 1.56% detergent. All corneas were fixed for scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Endothelial permeability was determined following perfusion of 0.78% detergent. Finally, in vivo intracameral injections with 1.56% or 3.9% detergent were performed to evaluate clinical changes and to correlate with histopathologic analysis.

RESULTS

Dose-related corneal swelling rates were observed. Digital specular micrographs revealed greater endothelial cell damage when perfused with 1.0% detergent. The TEM of endothelia exposed to 1.0% solutions demonstrated abnormal vacuolization and dilated extracellular spaces, which manifested as an increased corneal permeability to 3 to 4 times that of controls. Human corneas swelled comparably to rabbit corneas but demonstrated increased sensitivity when evaluated by TEM and SEM. Histopathologic analysis after intracameral injection revealed thickened corneas with fewer endothelial cells and irises with increased inflammatory and fibrinous responses compared with controls.

CONCLUSIONS

Medline Enzymatic Detergent causes a dose-dependent corneal swelling, ultrastructural damage, increased corneal permeability, and increased inflammatory response in the iris after intracameral injection.

CLINICAL RELEVANCE

Failure to adequately rinse the detergent from surgical instruments may result in corneal edema and intraocular inflammation.

Corneal toxicity of xylazine and clonidine, in combination with ketamine, in the rat

PURPOSE

To compare the corneal toxicity of xylazine (XYL)/ketamine (KET) with that of clonidine (CLO)/KET in the rat, in the presence or not of the alpha(2)-adrenergic antagonist yohimbine (YOH).

METHODS

XYL (10 mg/kg) and CLO (0.15 mg/kg) were administered subcutaneously in the rat in combination with KET (50 mg/kg), in the presence or not of YOH (2 mg/kg).

RESULTS

The corneas immediately lost transparency and luster, but recovered within 120 min. By both light and electron microscopy, a marked stromal edema and alterations of all layers were observed. In addition, XYL/KET altered the permeability of the cornea as indicated by the augmented levels of (14)C-indomethacin, topically administered 30 min after the anesthetic combination.

CONCLUSIONS

The mechanism of the corneal toxicity of XYL and CLO in the rat is unclear but we speculate that: (a) proptosis and inhibition of normal blinking did not play a major role because topical application of hyaluronic acid did not protect against it; corneal decompensation, edema and opacification could be due to (b) osmotic or (c) mechanical endothelial stress: the first resulting from the sudden increase of the glucose concentration in the aqueous humor due to the well-known inhibition of insulin release by alpha(2)-adrenergic agonists, and the second from the acute elevation of intraocular pressure caused by these alpha(2)-adrenergic mydriatics in the rat; (d) addition, XYL and CLO could act by directly interacting with local alpha(2)- or, possibly, alpha(1)-adrenergic receptors, whose function is still not clear but probably essential for corneal homeostasis.

Toxic endothelial cell destruction from intraocular benzalkonium chloride

PURPOSE

To present a cluster of cases of corneal edema occurring after phacoemulsification.

SETTING

Regional hospital in rural Australia.

METHODS

This retrospective case series comprised 12 patients from a single surgical list comprising 19 cases who developed persistent corneal edema after having phacoemulsification.

RESULTS

After 6 months, the edema improved in 1 patient. Inadvertent intraocular use of balanced salt solution (BSS) preserved with benzalkonium chloride was found to be the cause of this serious complication.

CONCLUSIONS

Benzalkonium chloride in concentrations commonly used extraocularly is highly toxic to the corneal endothelium. Every possible safeguard should be taken to prevent inadvertent intraocular use of such preserved solutions.

Interface fluid after laser in situ keratomileusis

We report a case in which raised intraocular pressure (IOP) was associated with interface fluid after uneventful bilateral laser in situ keratomileusis (LASIK). The patient presented with diffuse lamellar keratitis in both eyes 3 weeks postoperatively that was treated aggressively with topical corticosteroids. A steroid-induced rise in IOP resulted in interface fluid accumulation and microcystic edema. Measurements with the Goldmann tonometer revealed an IOP of 3.0 mm Hg in both eyes. However, Schiotz tonometry recorded a pressure of 54.7 mm Hg in both eyes. Reduction in the dosage of topical corticosteroid and medical treatment of the raised IOP resulted in resolution of the microcystic edema and interface fluid accumulation. This case highlights the inaccuracies of IOP measurement after LASIK and the resulting complications.