Hypopyon uveitis in patients with acquired immunodeficiency syndrome treated for systemic Mycobacterium avium complex infection with rifabutin

The Impact of Systemic Medications on Retinal Function

This study will provide a thorough review of systemic (and select intravitreal) medications, along with illicit drugs that are capable of causing various patterns of retinal toxicity. The diagnosis is established by taking a thorough medication and drug history, and then by pattern recognition of the clinical retinal changes and multimodal imaging features. Examples of all of these types of toxicity will be thoroughly reviewed, including agents that cause retinal pigment epithelial disruption (hydroxychloroquine, thioridazine, pentosan polysulfate sodium, dideoxyinosine), retinal vascular occlusion (quinine, oral contraceptives), cystoid macular edema/retinal edema (nicotinic acid, sulfa-containing medications, taxels, glitazones), crystalline deposition (tamoxifen, canthaxanthin, methoxyflurane), uveitis, miscellaneous, and subjective visual symptoms (digoxin, sildenafil). The impact of newer chemotherapeutics and immunotherapeutics (tyrosine kinase inhibitor, mitogen-activated protein kinase kinase, checkpoint, anaplastic lymphoma kinase, extracellular signal-regulated kinase inhibitors, and others), will also be thoroughly reviewed. The mechanism of action will be explored in detail when known. When applicable, preventive measures will be discussed, and treatment will be reviewed. Illicit drugs (cannabinoids, cocaine, heroin, methamphetamine, alkyl nitrite), will also be reviewed in terms of the potential impact on retinal function.

Pediatric uveitis: Role of the pediatrician

The challenges of childhood uveitis lie in the varied spectrum of its clinical presentation, the often asymptomatic nature of disease, and the evolving nature of the phenotype alongside normal physiological development. These issues can lead to delayed diagnosis which can cause significant morbidity and severe visual impairment. The most common ocular complications include cataracts, band keratopathy, glaucoma, and macular oedema, and the various associated systemic disorders can also result in extra-ophthalmic morbidity. Pediatricians have an important role to play. Their awareness of the various presentations and etiologies of uveitis in children afford the opportunity of prompt diagnosis before complications arise. Juvenile Idiopathic Arthritis (JIA) is one of the most common associated disorders seen in childhood uveitis, but there is a need to recognize other causes. In this review, different causes of uveitis are explored, including infections, autoimmune and autoinflammatory disease. As treatment is often informed by etiology, pediatricians can ensure early ophthalmological referral for children with inflammatory disease at risk of uveitis and can support management decisions for children with uveitis and possible underling multi-system inflammatory disease, thus reducing the risk of the development of irreversible sequelae.

Drug-induced uveitis: A review

Uveitis maybe induced by the use of various medications known as drug-induced uveitis (DIU), though rare it is an important cause of uveitis which one needs to be aware of. The drugs may be administered through any route including systemic, topical, and intravitreal. Ocular inflammation can be in the form of anterior, intermediate, posterior or pan uveitis, and rarely may present as episcleritis and scleritis. Identification of drug as the offending agent of uveitis is important as many a times stopping the drug may help recover the uveitis or the concomitant use of corticosteroids. An extensive literature review was done using the Pubmed. An overview of DIU is provided as it is important for us to be aware of this clinical entity.

Pharmacologically induced uveitis

Treatments of numerous systemic and local diseases of different etiologies may be accompanied by an unwanted side effect in the form of uveitis. We inform readers about medications that have the potential to cause uveitis and analyze the strength of association of these medications with uveitis. Subsequently, cessation of medication or appropriate treatment can be individualized for each patient for the purpose of preventing further damage to tissue structure and function. Being aware of these associations, physicians may readily identify medications that may cause uveitis and avoid expensive and unnecessary clinical and laboratory testing.

Drug-induced Uveitis in HIV Patients with Ocular Opportunistic Infections

Purpose: To describe drug-induced uveitis in immunocompromised patients diagnosed with Human Immunodeficiency Virus (HIV) infection Methods: Narrative Review Results: Systemic and intraocular medications administered for the treatment of acquired immune deficiency syndrome (AIDS)-associated diseases in patients infected with HIV are a well-known cause of uveitis. Conclusions: Cidofovir and rifabutin, among other novel anti-retroviral therapies, are strongly associated with drug-induced uveitis. It is imperative to understand the pathogenesis, clinical findings, and management of HIV patients with uveitis induced by these agents.

Antiretroviral treatment in HIV-infected children who require a rifamycin-containing regimen for tuberculosis

INTRODUCTION

In high prevalence settings, tuberculosis and HIV dual infection and co-treatment is frequent. Rifamycins, especially rifampicin, in combination with isoniazid, ethambutol and pyrazinamide are key components of short-course antituberculosis therapy. Areas covered: We reviewed available data, for which articles were identified by a Pubmed search, on rifamycin-antiretroviral interactions in HIV-infected children. Rifamycins have potent inducing effects on phase I and II drug metabolising enzymes and transporters. Antiretroviral medications are often metabolised by the enzymes induced by rifamycins or may suppress specific enzyme activity leading to drug-drug interactions with rifamycins. These may cause significant alterations in their phamacokinetic and pharmacodynamic properties, and sometimes that of the rifamycin. Recommended strategies to adapt to these interactions include avoidance and dose adjustment. Expert opinion: Despite the importance and frequency of tuberculosis as an opportunistic disease in HIV-infected children, current data on the management of co-treated children is based on few studies. We need new strategies to rapidly assess the use of rifamycins, new anti-tuberculosis drugs and antiretroviral drugs together as information on safety and dosing of individual drugs becomes available.

Bilateral uveitis associated with concurrent administration of rifabutin and nelfinavir

Rifabutin-associated uveitis has been recognized as a dosage-dependent side effect. Previous studies have reported that clarithromycin or fluconazole may elevate concentrations of rifabutin through inhibition of metabolism through the cytochrome P-450 pathway. Nelfinavir is a protease inhibitor widely used in the treatment of human immunodeficiency virus (HIV) infection. The interactions between protease inhibitors and rifabutin have not been reported in clinical practice. Therefore, we present a case of bilateral uveitis associated with coadministration of rifabutin and nelfinavir. Uveitis did not subside until discontinuation of rifabutin. To our knowledge, this is the first report of uveitis with concurrent administration of rifabutin and nelfinavir. Our finding reminds us that rifabutin dosage should be reduced when it is administered with protease inhibitors.

A Review of the Toxicity of HIV Medications II: Interactions with Drugs and Complementary and Alternative Medicine Products

For many patients today, HIV has become a chronic disease. For those patients who have access to and adhere to lifelong antiretroviral (ARV) therapy, the potential for drug-drug interactions has become a real and life-threatening concern. It is known that most ARV drug interactions occur through the cytochrome P450 (CYP) pathway. Medications for comorbid medical conditions, holistic supplements, and illicit drugs can be affected by CYP inhibitors and inducers and have the potential to cause harm and toxicity. Protease inhibitors (PIs) tend to inhibit CYP3A4, while most non-nucleoside reverse transcriptase inhibitors (NNRTIs) tend to induce the enzyme. As such, failure to adjust the dose of co-administered medications, such as statins and steroids, may lead to serious complications including rhabdomyolysis and hypercortisolism, respectively. Similarly, gastric acid blockers can decrease several ARV absorption, and warfarin doses may need to be adjusted to maintain therapeutic concentrations. Illicit drugs such as methylenedioxymethamphetamine (MDMA, "ecstasy") in combination with PIs lead to increased toxicity, while the concomitant administration of sedative drugs such as midazolam and alprazolam in patients taking PIs can result in prolonged sedation, delayed recovery, and increased length of stay. Even supplements like St. John's Wort can alter PI concentrations. In theory, any drug that is metabolized by CYP has potential for a pharmacokinetic drug-drug interaction with all PIs, cobicistat, and most NNRTIs. When adding a new medication to an ARV regimen, use of a drug-drug interaction software and/or consultation with a clinical pharmacist/pharmacologist or HIV specialist is recommended.

Drug-induced uveitis

INTRODUCTION

Drug-induced uveitis is a well described but often overlooked and/or misdiagnosed adverse reaction to medication. There are an increasing number of medications that have been related to the onset of intraocular inflammation. Identification of these inciting agents may decisively help the diagnostic algorithm involving new cases of uveitis.

AREAS COVERED

This review intends to be an updated comprehensive, practical guide for practitioners regarding the main drugs that have been associated with uveitis. A classification proposed by Naranjo et al. in 1981 for establishing potential causality is applied examining possible mechanisms of action. A guide for clinicians about the rationale of these observations when dealing with patients with uveitis is provided.

EXPERT OPINION

Several agents with different routes of administration (systemic, topical and/or intraocular) may cause intraocular inflammation. The mechanism behind ocular inflammation is frequently unknown. Clinicians should be aware of the potential drug effect to optimize diagnosis and management of such patients.

Uveitis in human immunodeficiency virus-infected persons with CD4+ T-lymphocyte count over 200 cells/mL

BACKGROUND

Introduction of highly active antiretroviral therapy has altered the course of disease for persons infected with human immunodeficiency virus by elevating CD4+ T-lymphocyte levels. Changes in the spectrum of systemic diseases encountered in human immunodeficiency virus-positive individuals are reported in the general medical literature.

DESIGN

Retrospective case series.

PARTICIPANTS

Sixty-one individuals infected with human immunodeficiency virus, who presented with uveitis when the peripheral CD4+ T-lymphocyte count was over 200 cells/μL.

METHODS

Standardized data collection at seven tertiary-referral inflammatory eye disease clinics.

MAIN OUTCOME MEASURES

Standardization of Uveitis Nomenclature anatomic classification and descriptors, cause of uveitis, and visual acuity

RESULTS

Peripheral CD4+ T cell counts varied between 207 and 1777 (median = 421) cells/μL at the time of diagnosis of uveitis. Uveitis was classified anatomically as anterior (47.5%), intermediate (6.6%), anterior/intermediate (16.4%), posterior (14.8%) and pan (14.8%). Specific causes of uveitis included infections (34.4%), with syphilis responsible for 16.4% of all cases, and defined immunological disorders (27.0%); no cause for the inflammation was identified in 34.4% of persons. Visual acuity was better than 6/15 in 66.7% and 6/60 or worse in 11.8% of 93 eyes at presentation, and better than 6/15 in 82.4% and 6/60 or worse in 8.8% of 34 eyes at 1 year of follow-up.

CONCLUSIONS

Both infectious and non-infectious forms of uveitis occur in individuals who are infected with human immunodeficiency virus and have preserved or restored peripheral CD4+ T cell levels. Individuals who are human immunodeficiency virus-positive and present with uveitis should be evaluated in the same way all patients with uveitis are assessed.

Drug-induced uveitis

A number of medications have been associated with uveitis. This review highlights both well-established and recently reported systemic, topical, intraocular, and vaccine-associated causes of drug-induced uveitis, and assigns a quantitative score to each medication based upon criteria originally described by Naranjo and associates.

Ocular toxicity from systemically administered xenobiotics

INTRODUCTION

The eye is considered as the most privileged organ because of the blood-ocular barrier that acts as a barrier to systemically administered xenobiotics. However, there has been a significant increase in the number of reports on systemic drug-induced ocular complications. If such complications are left untreated, then it may cause permanent damage to vision. Hence, knowledge of most recent updates on ever-increasing reports of such toxicities has become imperative to develop better therapy while minimizing toxicities.

AREAS COVERED

The article is mainly divided into anterior and posterior segment manifestations caused by systemically administered drugs. The anterior segment is further elaborated on corneal complications where as the posterior segment is focused on optic nerve, retinal and vitreous complications. Furthermore, this article includes recent updates on acute and chronic ocular predicaments, in addition to discussing various associated symptoms caused by drugs.

EXPERT OPINION

Direct correlation of ocular toxicities due to systemic drug therapy is evident from current literature. Therefore, it is necessary to have detailed documentation of these complications to improve understanding and predict toxicities. We made an attempt to ensure that the reader is aware of the characteristic ocular complications, the potential for irreversible drug toxicity and indications for cessation.

Rifabutin-Induced Thrombocytopenia from Concurrent Use of High-Dose Fluconazole

Objective:

To report a case of—and review the literature supporting—rifabutin-induced thrombocytopenia from concurrent use of high-dose fluconazole.

Case Summary:

A 34-year-old man with AIDS, on a stable regimen that included rifabutin and fluconazole for the previous 3 months, was admitted to the hospital with symptoms of oropharyngeal candidiasis. He was treated with increased doses of fluconazole 200 mg to 800 mg daily over a 9-day hospital admission. During this time, his platelet count decreased from 441,000 cells/mm3 to 24,000 cells/mm3, with no signs of bleeding. He was discharged on day 9 and instructed to omit 1 dose of rifabutin and continue fluconazole 200 mg daily. On day 12, his platelet count was 118,000 cells/mm3. About 1 month after discharge, his platelet count was 151,000 cells/mm3.

Discussion:

Rifabutin is known to cause thrombocytopenia. Results from initial studies evaluating various doses of rifabutin were not conclusive as to whether rifabutin-induced thrombocytopenia is a dose-dependent effect. With increased use of rifabutin, often in combination with potentially interacting medications, reports of thrombocytopenia have gained frequency. One study showed that patients on higher doses of rifabutin experienced thrombocytopenia significantly more often than did those on lower doses. When rifabutin is administered with fluconazole, there is a clear pharmacokinetic interaction, showing a 76–82% increase in the rifabutin area under the concentration curve, with only uveitis and leukopenia reported. An objective causality assessment of this case classified the interaction between fluconazole and rifabutin, resulting in thrombocytopenia, as probable. Other causes of thrombocytopenia in our patient, including AIDS, Mycobacterium avium complex, fluconazole, famotidine, and ritonavir, are less likely.

Conclusions:

We describe the first case of rifabutin-induced thrombocytopenia from concurrent use of high-dose fluconazole. There is evidence to support this interaction and practitioners should be aware of this potential adverse effect.

Diagnostic dilemmas in retinitis and endophthalmitis

Visual loss in infectious posterior uveitis or panuveitis can occur if proper therapy is delayed because of diagnostic uncertainty. Some disorders, such as acute retinal necrosis and bacterial endophthalmitis, can be rapidly progressive, and therefore require prompt and accurate diagnosis to guide initial therapy. Other more slowly evolving infections, such as toxoplasmic chorioretinitis or fungal endophthalmitis, can be worsened by empiric use of corticosteroids without specific antimicrobial coverage. Key ocular diagnostic features are helpful but highly variable with overlap with both non-infectious uveitis and neoplastic masquerades, even for key signs such as hypopyon. Close examination of the fundus with attention to color, location, size, border, and opacity of lesions and associated arteriolitis or frosted branch angiitis is helpful in the diagnosis of chorioretinitis. Ultrasonography is an important tool in the evaluation of eyes with suspected endophthalmitis, especially those with intracapsular infection or focal infected deposits. Testing of intraocular fluid can be extremely useful but suffers from inaccessibility, poor sensitivity, and test selections dependent on a presumptive diagnosis, which may be wrong. The dilemma for clinician is to make the correct diagnosis of a rare, blinding, variegated disease quickly enough to intercede with specific therapy or to apply empiric therapy in a sufficiently skilled manner to avert disaster and confirm the diagnosis by response to treatment. When non-infectious uveitis is in the differential, empiric corticosteroids must sometimes be used, at great risk, if clinical examination, ancillary testing, and any available intraocular diagnostic tests have failed to confirm a diagnosis.

ORIGINAL ARTICLE Posterior Intracorneal Opacities in Patients with HIV Infection

PURPOSE

To describe a keratopathy in patients with the human immunodeficiency virus (HIV) infection.

METHODS

Retrospective review of ophthalmic and medical records, including laboratory evaluations, of seven patients with HIV infection and posterior intracorneal opacities.

RESULTS

Each patient had a bilateral peripheral keratopathy located at the level of the Descemet membrane that was unassociated with intraocular inflammation. All patients were receiving highly active antiretroviral therapy (HAART). All patients had elevations in their CD4+ T-lymphocyte counts due to HAART prior to presenting with the corneal opacities. Five of the seven patients had elevated serum cholesterol, triglycerides, or both. Best-corrected visual acuity was 20/25 or better in six of the seven patients at the time of diagnosis, and vision remained stable through the follow-up period in all patients (median follow-up: 25 months; range: 14-82 months). The corneal opacities remained unchanged in all seven over the follow-up period.

CONCLUSION

These patients have a bilateral keratopathy that appears to be non-progressive and has no effect on visual acuity.

Acute panuveitis with hypopyon in Crohn's disease secondary to medical therapy: a case report

Background

A case report to highlight the association between rifabutin and hypopyon

Methods

A 56 year old male presented with a one day history of blurred vision in his right eye. He had an established diagnosis of Crohn's disease which was in remission following treatment with rifabutin and clarithromycin. A brisk anterior uveitis with hypopyon and a mild vitritis was detected in the right eye. The acute inflammatory episode resolved following treatment with topical corticosteroids and withdrawal of rifabutin.

Results

The presence of hypopyon is atypical in uveitis associated with inflammatory bowel disease. The association between rifabutin treatment and hypopyon uveitis is well recognised in Mycobacterium avium paratuberculosis. However, use of rifabutin in the management of Crohn's disease is controversial and not widely known to an ophthalmic readership.

Conclusion

This report highlights the importance of keeping abreast of novel therapeutic developments in systemic conditions likely to be encountered in ophthalmology.

Anterior Segment and External Ocular Disorders Associated with Human Immunodeficiency Virus Disease

The eye is a common site for complications of human immunodeficiency virus (HIV) infection. Although cytomegalovirus retinitis remains the most prevalent of the blinding ocular disorders that can occur in individuals with the acquired immunodeficiency syndrome (AIDS), several important HIV-associated disorders may involve the anterior segment, ocular surface, and adnexae. Some of these entities, such as Kaposi sarcoma, were well described, but uncommon, before the HIV epidemic. Others, like microsporidial keratoconjunctivitis, have presentations that differ between affected individuals with HIV disease and those from the general population who are immunocompetent. The treatment of many of these diseases is challenging because of host immunodeficiency. Survival after the diagnosis of AIDS has increased among individuals with HIV disease because of more effective antiretroviral therapies and improved prophylaxis against, and treatment of, opportunistic infections. This longer survival may lead to an increased prevalence of anterior segment and external ocular disorders. In addition, the evaluation and management of disorders such as blepharitis and dry eye, which were previously overshadowed by more severe, blinding disorders, may demand increased attention, as the general health of this population improves. Not all individuals infected with HIV receive potent antiretroviral therapy, however, because of socioeconomic or other factors, and others will be intolerant of these drugs or experience drug failure. Ophthalmologists must, therefore, still be aware of the ocular findings that develop in the setting of severe immunosuppression. This article reviews the spectrum of HIV-associated anterior segment and external ocular disorders, with recommendations for their evaluation and management.

Rifabutin-induced hypopyon uveitis in patients with acquired immunodeficiency syndrome infected with Mycobacterium avium complex

Rifabutin is a semi-synthetic antimycobacterial agent mainly used in the prophylaxis and treatment of Mycobacterium avium complex (MAC) in acquired immunodeficiency syndrome patients. Uveitis as a side effect of rifabutin has been recognized and established since 1994, but there was no case previously described in Taiwan so far. We report 2 cases of rifabutin-induced hypopyon uveitis in patients with human immunodeficiency virus and MAC infection. Both patients received the regimen of clarithromycin and rifabutin to treat MAC infection. Uveitis resolved after discontinuing of rifabutin and treatment with topical corticosteroid and mydriatics. Early recognition of this entity can prevent invasive ocular procedures and treatments. Doctors who prescribe rifabutin should be aware of this ocular complication of uveitis and drug-drug interactions. Ophthalmologists should put this on the list of differential diagnoses for uveitis.

Human immunodeficiency virus–positive patient with bilateral corneal endothelial deposits

BACKGROUND

Ocular disorders associated with the human immunodeficiency virus are numerous as are ocular side effects from medications used to treat all of the manifestations of the virus. This report presents a unique case of bilateral, peripheral, and corneal endothelial deposits that may be a result of either the human immunodeficiency virus or the medication rifabutin. Rifabutin was the only medication prescribed that is known to cause endothelial deposits. Rifabutin is part of a multidrug therapy to prevent or treat Mycobacterium avium complex, a common pulmonary disease of immunocompromised individuals.

CASE REPORT

A 69-year-old man with a 20-year history of being human immunodeficiency virus-positive presented with bilateral, asymptomatic, peripheral, and corneal endothelial deposits of unknown etiology. Literature research suggested that the deposits did not appear like cytomegalovirus retinitis-related deposits but rather a variant of rifabutin-associated deposits.

CONCLUSIONS

These rifabutin-associated deposits differed from known rifabutin-associated deposits previously reported in the literature. These deposits have increased in pigmentation and density 5 years after the patient discontinued the drug. This case may represent another variation of rifabutin-associated endothelial deposits. Knowledge of human immunodeficiency virus and all the associated ocular findings (owing to both the condition and its treatment) is important, because the length of time patients are living with human immunodeficiency virus is increasing.

Treatment of neuro-ophthalmologic manifestations of tuberculosis

In the absence of obvious pulmonary or disseminated tuberculosis, ocular and central nervous system (CNS) tuberculosis may represent a significant diagnostic challenge. Refinements in polymerase chain reaction techniques and neuroimaging have strengthened the battery of tests used to diagnose CNS and ocular tuberculosis, yet in many cases, the diagnosis remains one of exclusion; it may ultimately be determined through exacerbation by anti-inflammatory therapy with subsequent improvement by antitubercular medication treatment. Because of emerging drug resistance, at least a two-drug regimen is required for therapeutic testing and treatment of isolated ocular tuberculosis. If pulmonary or miliary disease coexists, a 6-month, four-drug regimen with isoniazid, rifampin, pyrazinamide, and ethambutol is required for treatment. Tubercular meningitis is treated with the same four-drug regimen for at least 9 to 12 months. Burden of therapeutic compliance rests on the treating physician and public health sector. Best compliance is realized with directly observed therapy.

Rifabutin-associated uveitis in a child

Uveitis associated with rifabutin treatment is a well-known adverse effect in adults with human immunodeficiency virus infection. In children, however, uveitis related to rifabutin has been reported in only a few cases. We present a case of rifabutin-associated uveitis in a human immunodeficiency virus-negative child. We review the literature and discuss special precautions to be considered when children are treated with rifabutin.

Ocular association of HIV infection in the era of highly active antiretroviral therapy and the global perspective

Ocular involvement is a common complication of HIV infection. Since the late 1990s, widespread use of highly active antiretroviral therapy (HAART) has altered the spectrum, and reduced the incidence of ocular involvement in developed countries. The incidence of the most common ocular opportunistic infection, cytomegalovirus retinitis, has decreased tremendously. However, immune recovery uveitis secondary to HAART has emerged as a frequent visually threatening condition. Early diagnosis and treatment with periocular steroids is helpful in minimizing visual loss. Clinicians should also be aware that certain antimicrobial agents used to treat opportunistic infections in HIV-positive patients are associated with potentially serious ocular side effects. In developing countries, where most of the world's 40 million HIV-positive patients live, the spectrum and incidence of ocular involvement differ from those in developed countries. The lack of HAART availability is among the many causes of these differences, which may include nutritional factors, basic medical care availability and the levels of exposure to different infectious agents. These factors add to the already challenging task of treating ocular complications and preventing blindness in HIV-positive patients in developing countries.

Corneal Endothelial Deposits Associated with Rifabutin Use

PURPOSE

The aim of this study was to report on the possible development of corneal endothelial deposits resulting from the use of rifabutin.

METHODS

Case series consisting of 3 patients treated with rifabutin were retrospectively studied. Two of the patients were infected with human immunodeficiency virus. A corneal and external disease specialist performed a complete ophthalmologic exam and obtained medical histories of the patients.

RESULTS

All cases developed corneal endothelial deposits after previous use of rifabutin. The deposits were bilateral, yellow-white colored, stellate, and mainly peripheral.

CONCLUSIONS

In these 3 cases, the unique positive ocular finding was corneal endothelial deposits, which may be related to the use of rifabutin.

Drug-induced corneal complications

PURPOSE OF REVIEW

To review the common corneal manifestations of systemic medications in order to describe the characteristic clinical features associated with particular systemic drugs, the indications for drug cessation, and the risks for irreversible ocular toxicity.

RECENT FINDINGS

Systemic medications may reach the cornea via the tear film, aqueous humor, and limbal vasculature. The corneal changes are often the result of the underlying chemical properties of medications. Amphiphilic medications (amiodarone, chloroquine, suramin, clofazimine, etc.) may produce a drug-induced lipidosis and development of a vortex keratopathy. Antimetabolites (cytarabine) may lead to a degeneration of basal epithelial cells with formation of epithelial microcysts. Additionally, systemically administered medications and drug metabolites may lead to a stromal or endothelial deposition. Corneal changes may result in reduced visual acuity, photophobia, and ocular irritation, though these symptoms typically resolve following drug cessation. Corneal manifestations of systemic medications are often dose related, and may reflect the potential risk for lenticular or retinal changes.

SUMMARY

Corneal changes secondary to systemic medications may affect all layers of the cornea. While corneal deposition is typically not an indication for drug cessation, patients receiving particular medications should be monitored for symptoms related to corneal deposition as well as for signs of irreversible ocular toxicity.

Retinal dysfunction and anterior segment deposits in a patient treated with rifabutin

PURPOSE

To describe the clinical and electrophysiological findings in a young boy with decreased vision possibly due to retinal damage by rifabutin.

METHODS

An 8-year-old boy with osteomyelitis was referred due to visual disturbance. During a period of 4 years, the boy was examined six times with electroretinography. Ophthalmological examination included testing of visual acuity, slit-lamp inspection, fundus inspection, fundus photography and kinetic perimetry. Two electrophysiological methods were performed for objective evaluation of retinal function, namely full-field electroretinography and multifocal electroretinography.

RESULTS

We found a slightly reduced visual acuity, a slowly increasing amount of yellow-white deposits on the posterior surface of the cornea and on the anterior part of the lens, a normal fundus appearance, and normal visual fields. However, the electroretinogram was abnormal on several occasions during therapy with rifabutin, but returned to normal 3 months after withdrawal of the medication. The multifocal electroretinogram returned to normal after the full-field electroretinogram had done so. The anterior chamber deposits still remain.

CONCLUSION

Long-term treatment with rifabutin may have a reversible and previously undescribed side-effect on retinal function. The drug may also accumulate irreversibly on the posterior surface of the cornea and on the anterior surface of the lens. We suggest that objective evaluation of retinal function with electrophysiological methods should be performed in patients with visual disturbance during treatment with rifabutin.

Human immunodeficiency virus-positive patients with posterior intracorneal precipitates

PURPOSE

To describe an unusual and possibly new keratopathy in human immunodeficiency virus (HIV)-positive patients.

DESIGN

Retrospective observational case series.

PARTICIPANTS

: Six HIV-positive patients at four centers.

METHODS

A complete medical history was obtained and a thorough ophthalmic examination was performed on each of the patients.

RESULTS

Each patient had bilaterally symmetrical keratopathy consisting of variably pigmented round and reticular posterior intracorneal precipitates at the level of Descemet's membrane. The precipitates were diffuse, but larger and more prominent near the limbus and finer toward the central cornea. None of the eyes were inflamed, and all had normal vision. No patient had uveitis on presentation or any history of cytomegalovirus retinitis.

CONCLUSION

These patients have a unique posterior keratopathy, which requires further investigation.

Rifabutin-associated hypopyon uveitis in human immunodeficiency virus-negative immunocompetent individuals

OBJECTIVE

To report the occurrence of rifabutin-associated hypopyon uveitis in human immunodeficiency virus (HIV)-negative immunocompetent individuals.

DESIGN

Retrospective case series.

PARTICIPANTS

Three HIV-negative subjects on rifabutin and clarithromycin for Mycobacterium avium complex infections with hypopyon uveitis are described. One subject was iatrogenically immunosuppressed because of a prior lung transplant. Two subjects had no known immunosuppressive conditions.

INTERVENTION

Topical and regional steroid therapy. Discontinuation of rifabutin was required in two subjects.

MAIN OUTCOME MEASURES

Visual acuity, resolution of hypopyon, anterior uveitis, and vitreitis.

RESULTS

All subjects had resolution of hypopyon after therapy, two within 24 hours of beginning topical steroids. Vitreitis resolved with the discontinuation of rifabutin in two subjects. Chronic low-grade anterior uveitis and vitreitis were observed in the remaining subject, whose rifabutin dose was lowered but not discontinued because of active Mycobacterium avium complex osteomyelitis.

CONCLUSIONS

Rifabutin-associated uveitis is well described in HIV-positive individuals, but it has been reported only once in an HIV-negative individual. We report two cases of hypopyon uveitis in immunocompetent individuals and one case in an immunosuppressed HIV-negative individual. All three subjects were receiving concurrent rifabutin and clarithromycin. Awareness that this entity can occur in HIV negative and nonimmunosuppressed individuals and that it can mimic infectious endophthalmitis may spare the subject from an invasive workup of systemic infection.

Rifabutin-induced uveitis with inflammatory vitreous infiltrate

PURPOSE

To describe an ocular complication of rifabutin therapy in the treatment of Mycobacterium avium complex (MAC) infection in the absence of HIV infection or AIDS.

METHODS

Three patients on rifabutin therapy for MAC chest infection developed anterior uveitis with vitreous infiltrates. The clinical course and visual outcome are discussed.

RESULTS

The ocular signs of anterior segment inflammation along with vitreous infiltrate resolved on topical steroid therapy without long-term visual sequelae.

CONCLUSION

This report highlights the potential of uveitis in patients treated for MAC infection with rifabutin without concurrent HIV infection or AIDS.

Uveitis in patients treated with intravenous cidofovir

PURPOSE

To study the characteristics of uveitis occurring during intravenous cidofovir treatment for CMV retinitis in patients with AIDS.

PATIENTS AND METHODS

We retrospectively studied ten cases (16 eyes) of uveitis in patients with CMV retinitis treated with intravenous cidofovir. All the patients had ophthalmologic examinations and, if required, fundus angiographies. The median follow-up was eight months.

RESULTS

Uveitis occurred after a mean of 8.5 infusions of cidofovir (range 2-17). All ten patients were on protease inhibitors. The mean CD4+ cell count was 92 +/- 51/microl and the median viral load was 3.9 log. All the eyes with uveitis had healed CMV retinitis. The first examination of the involved eyes showed inflammation of the anterior chamber (100%), vitritis (50%), posterior synechiae (75%), and low intraocular pressure (94%). Uveitis did not relapse in the seven patients who stopped cidofovir, whereas it relapsed in two of the three patients who did not stop treatment. At the end of follow-up, permanent posterior synechiae were present in 69% of the involved eyes.

COMMENTS

Cidofovir therapy necessitates slit-lamp surveillance, especially in patients on HAART. Cidofovir-related uveitis requires a local steroid treatment, but if possible, cidofovir should be withdrawn.

Symptomatic anterior uveitis in HIV-positive patients

Symptomatic anterior uveitis is rare in HIV-positive patients. The uveitis associated with cytomegalovirus retinitis (CMVR), the commonest ocular manifestation in AIDS patients, is rarely symptomatic and patients do not typically present with a red painful eye in conjunction with blurred vision. In this article we report 12 cases of symptomatic anterior uveitis in HIV-positive patients and discuss the aetiology. The case notes of all HIV-positive patients presenting to the eye department with symptoms of uveitis over a 4-year period were studied retrospectively. The notes were analysed for age, sex, race, risk factors of HIV, features of the uveitis, concurrent disease and CD4 counts. Only 12 patients were identified to have symptomatic uveitis out of a total 172 patients. There were 9 males and 3 females with an average age of 35 years. None of these patients were taking either rifabutin, protease inhibitors or cidofovir. Seven out of the 12 patients had granulomatous uveitis. Of these 7 patients, 4 had CD4 counts over 200 and no other concurrent illness whilst 3 patients, with CD4 counts between 130-200, were subsequently found to have an underlying aetiology namely lymphoma, tuberculosis and candida. The remaining 5 patients, all with CD4 counts below 40, had a history of systemic illness with herpes zoster preceding the onset of the uveitis. HIV-positive patients with symptoms of uveitis do not have active CMVR and the ophthalmologist must search for other causes such as tuberculosis or lymphoma in those with granulomatous uveitis or herpes zoster in those with non-granulomatous uveitis. The CD4 count may be helpful.

Corneal endothelial deposits in children positive for human immunodeficiency virus receiving rifabutin prophylaxis for Mycobacterium avium complex bacteremia

PURPOSE

To assess the potential ocular effects of prophylactic administration of rifabutin in children with symptomatic human immunodeficiency virus (HIV) infection and CD4 counts less than 50 cells per mm3.

METHODS

Twenty-five children with HIV infection were enrolled in a phase I-II study of prophylactic administration of systemic rifabutin for prevention of disseminated Mycobacterium avium complex infection and monitored prospectively for the development of ocular complications secondary to HIV infection or drug toxicity.

RESULTS

The dose of rifabutin ranged from 5.0 mg to 15.0 mg per kg, and the median ophthalmic follow-up was 24 months. During the study period, six of the children receiving rifabutin prophylaxis for M. avium complex developed unusual bilateral, initially peripheral, stellate, corneal endothelial deposits without associated uveitis. Review of serial corneal drawings and photographs showed an increase in the number of corneal deposits with continued administration of rifabutin. The duration of rifabutin treatment (P = .017) and follow-up (P = .0011) was significantly longer in patients who developed these corneal endothelial changes.

CONCLUSION

Corneal endothelial deposits should be considered a potential side effect of rifabutin therapy. To date, these findings have not been sight threatening.

Drug-induced uveitis

Uveitis has been reported in association with a variety of topical, intraocular, periocular, and systemic medications. To establish causality of adverse events by drugs, in 1981, Naranjo and associates proposed seven criteria, which are related to the frequency and documentation of the event; circumstances of occurrence, recovery, and recurrence; and coexistence of other factors or medications. Rarely does a drug meet all seven criteria. The authors review reports of drug-associated uveitis, applying the seven criteria and examining possible mechanisms. Only systemically administered biphosphonates and, perhaps, topical metipranolol meet all seven criteria. Systemic sulfonamides, rifabutin, and topical glucocorticoids fulfill at least five criteria.

Prophylaxis for disseminated Mycobacterium avium complex (MAC) infection in patients with AIDS: a cost-effectiveness analysis

OBJECTIVE

To determine the effectiveness and costs of prophylaxis for disseminated Mycobacterium avium complex (MAC) infection in patients with AIDS.

DESIGN

A decision analysis model was constructed to compare rifabutin (300 mg/day), azithromycin (1200 mg/week), and clarithromycin (500 mg twice per day) with no prophylaxis. Sensitivity analysis was done on all model parameters, including initial CD4 count for beginning prophylaxis.

SETTING

The setting was hypothetical for the cost-effectiveness model. Clinical data were taken from published prospective randomized controlled trials.

MAIN OUTCOME MEASURES

Outcomes were measured in terms of projected life expectancy, quality-adjusted life expectancy, direct medical costs, and cost-effectiveness in U.S. dollars per quality-adjusted life-year saved ($/QALY).

RESULTS

For patients with AIDS and those having CD4 counts <75 cells/mm3, azithromycin, clarithromycin, and rifabutin prophylaxis increased lifetime per person MAC-related costs by $994, $2,117, and $2,185 U.S., respectively. Quality-adjusted life expectancy increased from 1.6068 QALYs to between 1.6186 and 1.6255 QALYs. The cost-effectiveness ratios were $58,200, $116,000, and $179,100/QALY saved for azithromycin, clarithromycin, and rifabutin prophylaxis, respectively, each compared with no prophylaxis. Results were most dependent on the annual cost of prophylaxis, the initial CD4 count when starting prophylaxis, and any survival benefit with prophylaxis. For each type of prophylaxis, strategies beginning with CD4 counts <25 or 50 cells/mm3 were substantially more cost-effective than those beginning in patients with higher CD4 counts.

CONCLUSIONS

MAC prophylaxis is likely to cost society an additional $99 to $219 million U.S. per 100,000 patients treated. In the context of Centers for Disease Control and Prevention (CDC) recommendations to use prophylaxis in patients with CD4 counts <75 cells/mm3, azithromycin represents the best value and is most cost-effective when used in patients with CD4 counts <25 cells/mm3.