Topical Anesthetic Abuse Research Articles

Ring Keratitis Associated With Topical Abuse of a Dilute Anesthetic After Refractive Surgery

Anesthetic toxic keratitis is rare and presents as a ring keratitis, which is often misdiagnosed as Acanthamoeba keratitis. Here, we report an unusual case of toxic keratitis caused by topical abuse of a dilute anesthetic. A 26-year-old woman presented with bilateral corneal edema, ring infiltrates, pigmented keratic precipitate, Descemets membrane folding, and strong anterior chamber reactions 2 weeks after laser subepithelial keratomileusis surgery. Tracing back her medical history, topical dilute 0.1% proparacaine was prescribed and frequently used for 1 month. Toxic keratitis was suspected. After discontinuation of the topical anesthetic and initiation of treatment with topical 20% autologous serum, complete corneal epithelialization was achieved within 1 week. Corneal infiltrates and anterior chamber reaction gradually subsided. Vision improved from finger counting to 20/20 in the right eye and 20/25 in the left eye, but confocal microscopy showed decreased corneal endothelial cells. Topical abuse of a dilute topical anesthetic can cause severe toxic keratitis and endothelial cell loss. The physician must be aware of the signs of topical anesthetic abuse and should not prescribe even a dilute anesthetic for long-term use. Autologous serum can help in the recovery of toxic keratitis.

Clinical Findings in Patients with Topical Anaesthetic Abuse Keratitis: a Report of Five Cases

The purpose of this study is to describe the clinical findings in five patients with topical anaesthetic abuse. Five patients presented in the emergency department with persistent corneal epithelial defects associated with a ring infiltrate in the corneal stroma, without any referred history of ocular trauma or ocular application of any corrosive or alkali substance. The patients were hospitalised and a thorough ocular examination was accomplished. Systemic evaluation and psychiatric consultation were also done. A detailed history in all our patients revealed topical anaesthetic abuse keratitis. The topical anaesthetic was deliberately taken from the pharmacy without medical prescription. In all our patients a psychiatric disease and/or drug abuse was disclosed after psychiatric examination. The hallmark of topical anaesthetic abuse keratitis was a persistent corneal epithelial defect and a complete or incomplete ring infiltration of the corneal stroma in all cases. Functional and anatomic results after the appropriate treatment were not favourable in the majority of the cases, leading in some of them to blindness. Although topical anaesthetic abuse keratitis is rare, it should be considered in the differential diagnosis when we see a patient with a persistent corneal epithelial defect together with a ring infiltration on the corneal stroma. Psychiatric diseases and/or systemic drug abuse are usually associated with this toxic keratopathy. The psychiatric diseases that accompany this toxic keratopathy may also lead to death or to severe handicap as a result of suicide attempts by the patients. Psychiatric consultation and therapy are imperative in the management of such patients.

Clinical Case Notes

Two patients, both with a history of major depressive disorder, presented with large bilateral corneal epithelial defects and ring-shaped stromal opacities. Both were initially treated unsuccessfully with topical antibiotic therapy for presumed infectious keratitis. One patient eventually admitted to topical anaesthetic abuse. In the second patient, signs of topical anaesthetic abuse and Munchausen's syndrome became evident. Cessation of anaesthetic use resulted in rapid resolution of the corneal epithelial defects in both patients. Anaesthetic abuse keratopathy is often a manifestation of underlying psychiatric illness, and psychiatric intervention is a very important part of management. To the authors' knowledge, this is the first report of ocular Munchausen's syndrome manifesting as anaesthetic abuse keratopathy.

Topical anesthetic abuse after radial keratotomy

A 49-year-old woman developed corneal epithelial defects and stromal infiltration shortly after a 4-cut radial keratotomy (RK) for myopia. Although cultures. grew staphylococci and appropriate antibiotic treatment was applied, the epithetial defects increased in size. The corneal epithelium did not heal fully for more than 2 months. Penetrating keratoplasty 1 year later was followed by epithelial breakdown and perforation, as was a second keratoplasty. Despite repeated questioning, the patient did not admit until 18 months after her initial surgery that she had begun self-treatment with dilute proparacaine shortly after RK and continued it after her keratoplasties. The elective use of topical anesthetics to control pain after refractive-surgery should be approached with caution, and patients should be warned of the possible consequences of their misuse.

Topical Anesthetic Abuse Ring Keratitis

We present the clinicopathologic correlations of two case and two other clinical cases of topical anesthetic abuse keratopathy that were originally diagnosed as Acanthamoeba keratitis because of ring keratitis presentation and characteristic history. Four patients who were referred to us with suspected Acanthamoeba keratitis are included. Each was initially treated for amoebic keratitis, by using established protocols, and only later was the true origin (topical anesthetic abuse) uncovered. The clinical and surgical histories, pathologic analysis of the corneal specimens, and follow-up of < or = 4 years are included. Our four cases show another cause for ring infiltration of the cornea. Two cases resulted in corneal transplantation and multiple other medical or surgical treatments in an attempt to restore vision but had poor outcomes of finger-counting vision. Two other cases responded to intensive medical treatments with return of useful vision. Evaluation of the surgical specimens revealed a previously unpublished finding of near total cell death within the corneal stroma. Topical anesthetic abuse resulting in sight-threatening keratitis may be seen as a masquerade syndrome in many cases. Because of the often poor outcome, we must be aware of this entity, prevent abuse, and be vigilant in our prohibition of topical anesthetic for any therapeutic use.

Corneal Anesthetic Abuse and Candida Keratitis

Topical corneal anesthetic abuse is a self-inflicted injury, causing profound corneal morbidity. Superimposed infection is an important complicating factor. The authors report four patients with confirmed topical anesthetic abuse of the cornea, in whom Candida keratitis developed. A retrospective review of the medical records of four patients with confirmed topical corneal anesthetic abuse and fungal keratitis. A 21-year-old woman, two 28-year-old women, and a 35-year-old man were included in the study. All these patients sustained a corneal injury, prompting the chronic use of topical anesthetics (0.5% proparacaine hydrochloride in 3 patients, and 0.5% tetracaine hydrochloride and 0.4% benoxinate hydrochloride in the other). Corneal findings included epithelial defects in all patients, focal infiltrate in one patient, and ring-shaped stromal infiltrate in three patients. Topical anesthetic was discontinued, all patients initially were treated empirically with antibacterial agents, and three patients received topical corticosteroids. Subsequent corneal cultures grew Candida spp, Candida albicans specifically in three patients, and local and systemic antifungal therapy was started. Corneas in two patients re-epithelialized; a conjunctival flap was performed on another patient with a descemetocele; and the remaining patient was lost to follow-up, although repeat fungal cultures yielded no growth. Corneal superinfection with Candida may occur during topical anesthetic abuse. Therapy includes discontinuation of the anesthetic and institution of antifungal therapy.

Ultrastructural Alterations in the Endothelium in a Patient with Topical Anesthetic Abuse Keratopathy

A 40-year-old patient frequently self-administered topical oxybuprocaine drops for approximately 7 days after bilateral ultraviolet-light keratitis. Initially, he developed bilateral chronic epithelial defects with diffuse stromal infiltration and edema. After a protracted initial healing period, the patient underwent a penetrating keratoplasty in one eye because of significant corneal scarring. Pathologically, the corneal button revealed scarring and thinning of the central stroma. Results of scanning electron microscopy showed endothelial polymorphism, focal endothelial necrosis, and numerous filamentous processes emanating from abnormally enlarged intercellular gaps. Results of transmission electron microscopy showed markedly attenuated to absent apical cell attachments at the endothelial intercellular junction. Abuse of oxybuprocaine appears to produce irreversible damage to the apical cell attachments at the level of the corneal endothelial cells.

Topical Anesthetic Abuse

Topical ocular anesthetic abuse is a serious disorder causing keratitis and persistent epithelial defects. It may be the result of either prescription by the patient's eye care practitioner, theft from the practitioner's office, or occult additives in therapeutic medications. The authors report observations of six individuals suffering from this disorder which suggest that persistent epithelial defects, corneal stromal ring infiltrates, disproportionate pain, and prescription or nonprescription substance abuse may be factors involved. Penetrating keratoplasty was required to treat corneal perforation in two patients, and permanent corneal structural damage was noted in two eyes. Two eyes had a relentless downhill course culminating in enucleation. Because five of the six patients were diagnosed and treated as having presumed Acanthamoeba keratitis during the course of their disease, topical ocular anesthetic use should be included in the differential diagnosis of chronic keratitis and may masquerade as Acanthamoeba keratitis. The authors believe that practitioners should not prescribe or dispense topical anesthetics and should avoid clinical settings which provide an opportunity for the theft of topical ocular anesthetics.

Infectious Crystalline Keratopathy Associated with Topical Anesthetic Abuse

Two patients with infectious crystalline keratopathy associated with topical anesthetic abuse are described. No previously reported predisposing factors existed, including topical corticosteroid use during active Herpes simplex or Acanthamoeba keratitis, or following penetrating keratoplasty. Cultures from corneal biopsies of both patients grew Streptococcus viridans. Both infections resulted in corneal scarring with vascularization. Ultimately, corneal transplantation was performed in one case.