Treatment of cytomegalovirus retinitis with a sustained-release ganciclovir implant. The Ganciclovir Implant Study Group

Treatment of cytomegalovirus retinitis with oral valganciclovir in an acquired immunodeficiency syndrome patient unresponsive to combination antiretroviral therapy

BACKGROUND

Cytomegalovirus (CMV) retinitis was a much-feared visual complication of late-stage acquired immunodeficiency syndrome (AIDS) in the past. Its incidence has waned significantly owing to the benefits of potent antiretroviral combination therapy, which for many individuals has provided some degree of immune reconstitution and avoidance of opportunistic infections, particularly this blinding disease.

CASE REPORT

A 45-year-old white man with long-standing, multidrug-resistant human immunodeficiency virus (HIV) infection and severe immunodeficiency despite multiple antiretroviral drug regimens, presented to the eye clinic reporting decreased vision and spider web patterns in his left eye for the past week. Best-corrected visual acuity was 20/20 in the right (O.D.) and 20/25 in the left eye (O.S.). Dilated funduscopic examination of the left eye found vasculitis of the midperipheral inferonasal arcade in the midperiphery, with surrounding intraretinal hemorrhage and granular retinal necrosis. Diagnosis of cytomegalovirus retinitis was made, and the patient began induction therapy with oral valganciclovir 900 mg twice a day for 3 weeks. Maintenance therapy after retinitis stabilization was 900 mg every day until any observed recurrence of infection. Three months after complete resolution of the active retinitis, the patient returned to the clinic reporting new floaters of recent onset. A reactivation of the CMV retinitis warranted a reinduction with valganciclovir 900 mg orally twice a day for 3 weeks.

CONCLUSION

This case is illustrative of the efficacy and relative ease of administration of valganciclovir, the newest medication approved for treatment and maintenance of CMV retinitis. Despite his severe immunodeficiency, our patient tolerated the induction and maintenance therapy of oral valganciclovir well, and the CMV retinitis was stabilized and resolved with full recovery of visual acuity.

An in vitro study of the design and development of a novel doughnut-shaped minitablet for intraocular implantation

A novel doughnut-shaped minitablet (DSMT) was developed and evaluated as a biodegradable intraocular drug delivery system for rate-modulated delivery of antiviral bioactives. The DSMT device was manufactured using a special set of punches fitted with a central-rod in a Manesty tableting press. The DSMT device released the antiretrovirals foscarnet and ganciclovir at a first-order rate. The erosion kinetics was assessed by gravimetric analysis and scanning electron microscopy. The device gradually eroded when immersed in simulated vitreous humor (SVH) (pH 7.4, 37 degrees C) and released bioactives in a sustained manner. The novel geometric design and veracity of the DSMT device was retained even after 24 weeks of erosion. When considering the duration of the bioactive released from the DSMT device, it was found that by the careful selection of the type and concentration of polymer employed in formulating the DSMT device, it was possible to produce a device that could release drug for any period up to 12 months.

Biocompatibility of elastin-like polymer poly(VPAVG) microparticles:in vitro andin vivo studies

Poly(L-valine-L-proline-L-alanine-L-valine-L-glycine) (VPAVG) is a new kind of proteinaceous polymer belonging to the Elastin-like family. These polymers are based on the recurrence of certain short peptide monomers that are considered as "building blocks" in the natural elastin. This smart thermoresponsive polymer has the ability to self-associate at physiological temperature to form aggregates with about 60% in water. This ability can be harnessed to prepare microparticles loaded with an active substance. The aim of this report is to evaluate, from the results of the experiment conducted, the biocompatibility of microparticles prepared from poly(VPAVG). We have studied the cytotoxic effects of microparticles, edema formation after subcutaneous injection (1 and 2.5 mg) in rats (n = 6), and also intraocular tolerance after the intravitreal injection of 2.5 mg of poly(VPAVG) microparticles into pigmented rabbits (n = 12). The polymer did not induce any cytotoxicity or nonspecific depression of cellular respiration on macrophages under the range of polymer concentrations investigated in this study (20, 30, 40, and 60 mg/mL). We observed no inflammatory response to microparticles after subcutaneous injection in the hind-paw of rats, with no significant differences between the control group (PBS) and experimental groups. Anterior and posterior segment signs were evaluated after intraocular injection of poly(VPAVG) microparticles. Only a few eyes (2/11) of the experimental group presented inflammation signs at day 28 postinjection. Nevertheless, 45% (5/11) of the eyes receiving microparticles showed tractional retinal detachment. The results observed in this work suggested certain fibroblastic activity induced by poly(VPAVG) microparticles after their intraocular injection.

Ganciclovir implant in the treatment of cytomegalovirus retinitis

The ganciclovir implant is a sustained-release intraocular drug delivery system used to treat cytomegalovirus retinitis that provides a high and steady-state concentration of the drug in the vitreous cavity over a period of 7-8 months. Randomized, controlled clinical trials have demonstrated a superior efficacy of the implant compared with intravenous ganciclovir. Severe adverse events associated with the implant are uncommon, though potentially blinding. In addition, the implant provides no protection against second-eye or visceral cytomegalovirus retinitis infections. This review summarizes the clinical indications for and complications associated with the ganciclovir implant.

HIV-associated retinopathy in the HAART era

BACKGROUND

The effectiveness of highly active antiretroviral therapy (HAART) in restoring immune function in patients with acquired immunodeficiency syndrome (AIDS) has led to changes in the incidence, natural history, management, and sequelae of human immunodeficiency virus (HIV)-associated retinopathies, especially cytomegalovirus (CMV) retinitis.

METHODS

The medical literature pertaining to HIV-associated retinopathies was reviewed with special attention to the differences in incidence, management strategies, and complications of these conditions in the eras both before and after the widespread use of HAART.

RESULTS

In the pre-HAART era, CMV retinitis was the most common HIV-associated retinopathy, occurring in 20%-40% of patients. Median time to progression was 47 to 104 days, mean survival after diagnosis was 6 to 10 months, and indefinite intravenous maintenance therapy was mandatory. Retinal detachment occurred in 24%-50% of patients annually. Herpetic retinopathy and toxoplasmosis retinochoroiditis occurred in 1%-3% of patients and Pneumocystis carinii choroiditis, syphilitic retinitis, tuberculous choroiditis, cryptococcal choroiditis, and intraocular lymphoma occurred infrequently. In the HAART era the incidence of CMV retinitis has declined 80% and survival after diagnosis has increased to over 1 year. Immune recovery in patients on HAART has allowed safe discontinuation of maintenance therapy in patients with regressed CMV retinitis and other HIV-associated retinopathies. Immune recovery uveitis (IRU) is a HAART dependent inflammatory response that may occur in up to 63% of patients with regressed CMV retinitis and elevated CD4 counts and is associated with vision loss from epiretinal membrane, cataract, and cystoid macular edema.

CONCLUSIONS

The incidence, visual morbidity, and mortality of CMV retinitis and other HIV-associated retinopathies have decreased in the era of HAART and lifelong maintenance therapy may safely be discontinued in patients with restored immune function. Patients with regressed CMV retinitis, however, may still lose vision from epiretinal membrane, cystoid macular edema, and cataract secondary to IRU.

Valganciclovir: a review of its use in the management of CMV infection and disease in immunocompromised patients

Valganciclovir (Valcyte) is an orally administered prodrug of the standard anti-cytomegalovirus (CMV) drug ganciclovir. Valganciclovir is as effective as intravenous ganciclovir for the treatment of AIDS-related CMV retinitis, and oral ganciclovir for the prophylaxis of CMV infection and disease in high-risk solid organ transplant recipients. The drug is generally well tolerated and has a similar tolerability profile to that of oral or intravenous ganciclovir, but is devoid of adverse events related to intravenous or indwelling catheter access associated with the use of intravenous ganciclovir, cidofovir and foscarnet. The simple and convenient once-daily valganciclovir regimen offers potential for improved patient compliance. It provides greater systemic ganciclovir exposure than oral ganciclovir, thus reducing the risk of viral resistance when used for prophylaxis in high-risk solid organ transplant recipients. Furthermore, the use of valganciclovir instead of intravenous ganciclovir may provide significant cost savings, based on data comparing oral versus intravenous regimens for the treatment of AIDS-related CMV retinitis. Overall, valganciclovir appears to have some advantages over ganciclovir. Therefore, when used as prophylaxis against CMV infection and disease in high-risk solid organ transplant recipients or as induction and maintenance therapy of CMV retinitis in patients with AIDS, oral valganciclovir is an attractive alternative to other available anti-CMV drugs.

Incidence of cytomegalovirus (CMV) retinitis in second eyes of patients with the acquired immune deficiency syndrome and unilateral CMV retinitis

PURPOSE

To evaluate the risk and risk factors for developing cytomegalovirus (CMV) retinitis in previously uninvolved second eyes among patients with unilateral CMV retinitis.

DESIGN

Cohort study.

METHODS

SETTINGS

Single-center academic AIDS ophthalmology practice.

PATIENT POPULATION

Three hundred seventy-six consecutive patients with AIDS and unilateral CMV retinitis were followed from the time of CMV retinitis diagnosis for the development of second-eye retinitis.

EXPERIMENTAL PROCEDURES

Demographic and clinical characteristics were noted at baseline. Use of highly active antiretroviral therapy (HAART) and immune recovery in response to HAART were noted prospectively.

MAIN OUTCOME MEASURE

Development of CMV retinitis in a previously uninvolved eye.

RESULTS

Ninety-one percent of subjects received systemic anti-CMV treatment. Second-eye retinitis occurred in 26.1%/person-year (19.6% within the first 6 months), less than half the rate previously reported in untreated groups. Initial CD4+ T cell count >12 cells/microl, use of HAART, and initial posterior pole involvement were associated with 64%, 46%, and 41% reductions in incidence vis-à-vis comparison groups. Benefit from HAART was limited to that subset who developed immune recovery of a degree expected to restore innate control of CMV (a rise in the CD4+ T cell count by >50 cells/microl to a level >100 cells/microl).

CONCLUSIONS

The risk of second-eye retinitis is substantial in patients with unilateral CMV retinitis but appears to be reduced by anti-CMV therapy and by HAART-induced immune recovery. Patients are at highest risk when CD4+ T cell counts are very low and in the months immediately after CMV retinitis diagnosis.

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.

Emerging drugs for ophthalmic diseases

The ocular system is crucial to survival. It is subject to many of the same diseases found in other organ systems (e.g., diabetes) as well as diseases of ageing (e.g., macular degeneration) and other diseases (e.g., myopia). This review describes ocular diseases which are treatable, or potentially treatable, by pharmacological intervention (e.g., glaucoma, ocular infection, ocular allergy, ocular inflammation, dry eye and retinal pathology). Presented is a background of these diseases, the medical need for therapy, and current and potential new treatments.

[Treatment and prophylaxis of opportunistic infections in the course of HIV disease: a state of the art in 2004. Part 2: Viral, fungal and bacterial infections]

Remarkable progress has been made in antiretroviral therapeutics, as well as in the prophylaxis and treatment of opportunistic infections, since the beginning of the AIDS epidemic. The patient's life expectancy and quality of life have consequently improved, thanks to better management of opportunistic diseases. The introduction of protease inhibitors-containing regimen (i.e. highly active antiretroviral therapy or HAART), since 1996, has drastically reduced the incidence of opportunistic infections by restoring immunity. The large panel of antiretroviral drugs responsible for frequent sustained viral and immune responses has thus allowed a new definition of guidelines for the prophylaxis and treatment of opportunistic infections. A better use of prophylactic drugs should help to reduce the risk of drug-related toxicity and pharmaceutical interactions. It should also decrease the cost of HIV management and eventually increase compliance to treatment and quality of life.

Ocular pharmacokinetics of fluocinolone acetonide after Retisert intravitreal implantation in rabbits over a 1-year period

PURPOSE

The present study was designed to examine the pharmacokinetics of a fluocinolone acetonide (FA) intravitreal implant in pigmented rabbits.

METHODS

Pigmented rabbits were randomly assigned to receive either a 0.5 mg or 2.0 mg FA intravitreal implant (Retisert). Four animals were sacrificed per time point (2 hours; 2 weeks; and 3, 6, 9, and 12 months after implantation) for FA intraocular levels determination.

RESULTS

In the vitreous, concentration of FA was relatively constant from the first time point, 2 hours, through 1 year, and dose-related, approximately seven- to eight-fold greater in the 2-mg implant. Concentrations of FA were generally higher in the vitreous (11-18 and 75-146 ng/g) and retina (42-87 and 224-489 ng/g) than in the aqueous humor (0.21-1.1 and 2.6-13.0 ng/g) for the 0.5- and 2-mg implants, respectively. Urine and plasma values were below the lower limit of quantitation (200 pg/mL) for all observations, indicating no evidence of systemic absorption.

CONCLUSIONS

In this rabbit study, the Retisert provides relatively constant levels of FA in the posterior pole, which is consistent with previous reports of its clinical utility.

Canadian consensus guidelines for the management of cytomegalovirus disease in HIV/AIDS

BACKGROUND

The management of HIV-infected patients with cytomegalovirus (CMV) disease has changed significantly with the availability of highly active antiretroviral therapy (HAART).

OBJECTIVES

These updated guidelines are intended to provide practical help to physicians managing HIV-positive patients with or at risk for CMV disease.

METHODS

The 10 members of the Canadian CMV Disease in HIV/AIDS Consensus Group were infectious disease specialists, a primary care physician and ophthalmologists with expertise in HIV and CMV infection. Financial support by Hoffmann-La Roche Canada Ltd was unrestricted, and was limited to travel expenses and honoraria. The consensus group met in June and October 2002. Key areas to be considered were identified, and group members selected, reviewed and presented relevant recent literature for their assigned section for the group's consideration. Evidence was assessed based on established criteria, which were expert opinions of the members. Draft documents were circulated to the entire group and modified until consensus was reached. The final guidelines represent the group's consensus agreement. The guidelines were approved by the Canadian Infectious Disease Society.

RESULTS AND CONCLUSIONS

The guidelines address symptom monitoring, screening for early detection and prevention, and treatment using oral, intravenous and intraocular anti-CMV therapies in conjunction with HAART.

Drug delivery systems for vitreoretinal diseases

The eye has an environment that is specific unto itself in terms of pharmacokinetics: the inner and outer blood-retinal barriers separate the retina and the vitreous from the systemic circulation and vitreous body, which physiologically has no cellular components, occupies the vitreous cavity, an inner space of the eye, and reduces practical convection of molecules. Considering this, development of a drug delivery system (DDS) is becoming increasingly important in the treatment of vitreoretinal diseases not only to facilitate drug efficacy but also to attenuate adverse effects. The DDS has three major goals: enhances drug permeation (e.g., iontophoresis and transscleral DDS), controls release of drugs (e.g., microspheres, liposomes, and intraocular implants), and targets drugs (e.g., prodrugs with high molecular weight and immunoconjugates). Comprehensive knowledge of these should lead to development of innovative treatment modalities.

Retinal toxicity of intravitreal ganciclovir in rabbit eyes following vitrectomy and insertion of silicone oil

BACKGROUND

Although intravitreal ganciclovir dosages up to 500 microg have been demonstrated to be safe in some studies, other studies have shown toxic retinal effects in rabbit eyes without silicone oil at lower dosages. In current clinical practice, the same dosage of intravitreal antiviral agent is given regardless of whether there has been retinal detachment repair with silicone oil. We performed a study to investigate, in rabbit eyes following vitrectomy and silicone oil insertion, the retinal toxicity of serial intravitreal injections of ganciclovir, using dosages previously found not to produce significant toxic effects in nonvitrectomized eyes.

METHODS

Twenty-eight eyes of 14 New Zealand pigmented rabbits underwent pars plana vitrectomy and silicone oil insertion. One eye of each animal received an intravitreal ganciclovir injection twice weekly for 2 weeks. The other eye received 0.1 mL of normal saline as a control. Three dosages of ganciclovir (50, 100 or 200 microg/0.1 mL) were used in three groups of three to six animals. Scotopic electroretinography and histologic examination were performed 2 weeks postoperatively.

RESULTS

No differences in scotopic b-wave threshold (p = 0.23, 0.78 and 0.50 for ganciclovir dosages of 50, 100 and 200 microg/0.1 mL respectively, Mann-Whitney U test) or in light microscopy findings were noted between the treatment and control eyes at any dosage of ganciclovir. Surgical complications were observed in eight eyes; the data for these eyes were not used for analysis.

INTERPRETATION

Ganciclovir dosages of up to 200 microg/0.1 mL appear to be safe for serial intravitreal injection in rabbit eyes following vitrectomy and silicone oil insertion.

Complications of ganciclovir implant surgery in patients with cytomegalovirus retinitis: the Ganciclovir Cidofovir Cytomegalovirus Retinitis Trial

PURPOSE

To describe the complications of ganciclovir implant surgery in patients with cytomegalovirus retinitis.

METHODS

Prospective data collection within the context of a randomized, controlled clinical trial, comparing a regimen of the ganciclovir implant plus oral ganciclovir to one of intravenous cidofovir for the treatment of cytomegalovirus retinitis in patients with AIDS. Adverse events were compared for patients undergoing implant surgery in the following groups: primary versus replacement implant surgery, inpatient versus outpatient surgery, and general versus local anesthesia.

RESULTS

Fifty-six eyes of 42 patients underwent a total of 74 ganciclovir implant surgeries. Vitreous hemorrhage was the most common adverse event, occurring in 10% of eyes undergoing surgery with local anesthesia but in no eyes undergoing surgery with general anesthesia. All vitreous hemorrhages resolved within 60 days. Patients in the general anesthesia and inpatient surgery groups tended to have a lower risk of complications in the first 30 days than did patients in the local anesthesia and outpatient surgery groups, but no differences in the complication rate were found after 60 days. Visual acuity was similar among these different groups. There were no cases of endophthalmitis.

CONCLUSION

Ganciclovir implant surgery in patients with AIDS and cytomegalovirus retinitis was associated with a low risk of serious complications in the first 60 days after surgery. Vitreous hemorrhage was the most commonly observed complication and resolved in all cases.

Posterior segment manifestations of HIV/AIDS

The ocular posterior segment manifestations of AIDS may be divided into four categories: retinal vasculopathy, unusual malignancies, neuro-ophthalmologic abnormalities, and opportunistic infections. Microvasculopathy is the most common manifestation. Opportunistic infections, particularly cytomegalovirus retinitis and progressive outer retinal necrosis, are the most likely to result in visual loss due to infection or subsequent retinal detachment. Diagnosis and treatment are guided by the particular conditions and immune status of the patient.

Prevention of opportunistic infections in adult and adolescent patients with HIV infection. GESIDA/National AIDS Plan guidelines, 2004 [correction]

OBJECTIVE

To provide an update of guidelines from the Spanish AIDS Study Group (GESIDA) and the National AIDS Plan (PNS) committee on the prevention of opportunistic infections in adult and adolescent HIV-infected patients.

METHODS

These consensus recommendations have been produced by a group of experts from GESIDA and/or the PNS after reviewing the earlier document and the scientific advances in this field in the last years. The system used by the Infectious Diseases Society of America and the United States Public Health Service has been used to classify the strength and quality of the data.

RESULTS

This document provides a detailed review of the measures for the prevention of infections caused by viruses, bacteria, fungi and parasites in the context of HIV infection. Recommendations are given for preventing exposure and for primary and secondary prophylaxis for each group of pathogens. In addition, criteria are established for the withdrawal of prophylaxis in patients who respond well to highly active antiretroviral therapy (HAART).

CONCLUSIONS

HAART is the best strategy for the prevention of opportunistic infections in HIV-positive patients. Nevertheless, prophylaxis is still necessary in countries with limited economic resources, in highly immunodepressed patients until HAART achieves beneficial effects, in patients who refuse to take or who cannot take HAART, in those in whom HAART is not effective, and in the small group of infected patients with inadequate recovery of CD4+ T lymphocyte counts despite good inhibition of HIV replication.

Incidence and management of cataract after retinal detachment repair with silicone oil in immune compromised patients with cytomegalovirus retinitis

PURPOSE

To determine the incidence of and risk factors for cataract and to describe the visual outcomes of cataract surgery in eyes with cytomegalovirus-related retinal detachments repaired with silicone oil.

STUDY DESIGN

Retrospective cohort study.

METHODS

A prospectively generated database of all patients with cytomegalovirus retinitis examined at a single tertiary care institution was used to identify all cases of retinal detachment between October 1983 and August 1997. Data on retinal detachment repair, development of cataract, and outcomes of cataract surgery were obtained retrospectively.

RESULTS

Among 904 eyes of 587 immune-compromised patients diagnosed with cytomegalovirus retinitis, 198 eyes of 155 patients developed retinal detachment. Among these, 106 eyes of 90 patients underwent retinal detachment repair with silicone oil. The Kaplan-Meier estimated median time to cataract was 1.8 months after surgery with silicone oil. The adjusted relative risk of cataract in eyes that underwent retinal detachment repair with silicone oil compared with eyes that did not was 6.74 (P <.0001). Eight of the eyes that developed cataract underwent uncomplicated cataract surgery by phacoemulsification and posterior chamber intraocular lens implantation. Among these, six eyes experienced >or=2 lines of improvement in visual acuity. All developed posterior capsule opacification a median of 7 days after cataract surgery. Four of five eyes that that underwent neodymium:yttrium-aluminum-garnet laser capsulotomy experienced >or=2 lines improvement in visual acuity.

CONCLUSIONS

There is a high incidence of cataract after surgery with silicone oil tamponade for cytomegalovirus-related retinal detachment. Posterior capsule opacification occurs rapidly after cataract surgery in these patients.

Retinal and Optic Nerve Diseases

A variety of disease processes can affect the retina and/or the optic nerve, including vascular or ischemic disease, inflammatory or infectious disease, and degenerative disease. These disease processes may selectively damage certain parts of the retina or optic nerve, and the specific areas that are damaged may have implications for the design of potential therapeutic visual prosthetic devices. Outer retinal diseases include age-related macular degeneration, pathologic myopia, and retinitis pigmentosa. Although the retinal photoreceptors may be lost, the inner retina is relatively well-preserved in these diseases and may be a target for retinal prosthetic devices. Inner retinal diseases include retinal vascular diseases such as diabetic retinopathy, retinal venous occlusive disease, and retinopathy of prematurity. Other retinal diseases such as ocular infections (retinitis, endophthalmitis) may affect all retinal layers. Because the inner retinal cells, including the retinal ganglion cells, may be destroyed in these diseases (inner retinal or whole retinal), prosthetic devices that stimulate the inner retina may not be effective. Common optic nerve diseases include glaucoma, optic neuritis, and ischemic optic neuropathy. Because the ganglion cell nerve fibers themselves are damaged, visual prosthetics for these diseases will need to target more distal portions of the visual pathway, such as the visual cortex. Clearly, a sound understanding of retinal and optic nerve disease pathophysiology is critical for designing and choosing the optimal visual prosthetic device.

Mortality risk for patients with cytomegalovirus retinitis and acquired immune deficiency syndrome

We prospectively followed up 589 patients to evaluate the relationship of anti-cytomegalovirus (CMV) treatment and immune reconstitution in response to highly active antiretroviral therapy (HAART) on the mortality risk of patients with CMV retinitis and acquired immune deficiency syndrome. The use of HAART was associated with an 81% lower mortality rate (95% confidence interval [CI], 74%-86%); it was 96% lower (95% CI, 92%-98%) for those who developed immune recovery and 49% lower (95% CI, 30-63%) for those who did not. Using time-updated multivariate analysis, current systemic anti-CMV treatment was independently associated with a 28% lower mortality rate (95% CI, 8%-43%). On the basis of these results, for patients who continue to have profound immunodeficiency despite HAART, the continued use of HAART and systemic anti-CMV therapy is predicted to reduce the risk of mortality by 65%, over and above the benefits of Pneumocystis carinii and Mycobacterium avium prophylaxis.

Endophthalmitis after ganciclovir implant in patients with AIDS and cytomegalovirus retinitis

PURPOSE

To describe the incidence, clinical course, and outcomes of endophthalmitis in patients treated with a ganciclovir implant.

DESIGN

Retrospective review of cases identified from a clinical survey.

METHODS

Cases of endophthalmitis were identified from a survey of 30 clinical practices known to treat a large number of patients with cytomegalovirus retinitis.

RESULTS

Twenty-four cases of endophthalmitis were identified from 5185 implants performed (incidence, 0.46%). Final visual acuity ranged from 20/20 to no light perception, with 50% (12/24) seeing light perception or worse. Vitreous cultures revealed Staphylococcus epidermidis in 29% (7/24) of patients, whereas other gram-positive organisms were responsible in 42% (10/24) of cases. In the remaining 29% (7/24) of cases, no organisms were cultured; these cases exhibited a better visual outcome (P =.007). Six of the eight late-onset cases were associated with wound problems such as implant strut or suture exposure. There was no significant relationship between implant removal and final visual acuity.

CONCLUSIONS

Endophthalmitis is an infrequent but potentially devastating complication associated with placement of a ganciclovir implant.

Periocular injection of an adenoviral vector encoding pigment epithelium-derived factor inhibits choroidal neovascularization

Gene transfer provides an exciting new approach for the treatment of retinal and choroidal diseases. Two areas of concern are the potential for vector-related toxicity and uncertainties associated with prolonged transgene expression. One way to address these concerns for transfer of genes encoding secreted proteins is to transduce cells on the outside of the eye, provided the gene product can gain access to the eye and have the desired effect. In this study, we investigated the feasibility of this approach. Periocular injection of an adenoviral vector encoding beta-galactosidase (AdLacZ.10) resulted in LacZ-stained cells throughout the orbit and around the eye. Compared to periocular injection of 5 x 10(9) particles of control vector, periocular injection of 5 x 10(9) or 1 x 10(9) particles of an adenoviral vector expressing pigment epithelium-derived factor (PEDF) regulated by a CMV promoter (AdPEDF.11) resulted in significantly elevated intraocular levels of PEDF and suppression of choroidal neovascularization. Periocularly injected recombinant PEDF was also found to diffuse through the sclera into the eye. Although similar experiments are needed in an animal with a human-sized eye, these data suggest that periocular gene transfer deserves consideration for the treatment of choroidal diseases.

Cytomegalovirus resistance to ganciclovir and clinical outcomes of patients with cytomegalovirus retinitis

PURPOSE

To evaluate whether cytomegalovirus resistant to ganciclovir, detected in either the blood or urine, correlates with adverse ocular outcomes.

DESIGN

Prospective cohort study.

METHODS

Patients with cytomegalovirus and AIDS were enrolled in a study of the occurrence and clinical correlates of resistant cytomegalovirus. Blood and urine cultures for cytomegalovirus were performed at the time of diagnosis of retinitis, 1 and 3 months after the initiation of therapy, and every 3 months thereafter. Patients were seen monthly, at which time fundus photographs were obtained and forwarded to the Fundus Photograph Reading Center for evaluation of retinitis progression (movement of a border of a cytomegalovirus lesion > or = 750 microm, or the occurrence of a new lesion > or = 0.25 disk area in size) and the amount of retinal area affected by cytomegalovirus retinitis. Visual acuity was measured using logarithmic visual acuity charts. Phenotypic resistance to ganciclovir was defined as an IC50 > 6.0 micromol/l, and genotypic resistance to ganciclovir was defined as the occurrence of a cytomegalovirus UL97 gene mutation known to confer ganciclovir resistance. Time-dependent analyses were performed and included viral resistance, highly active antiretroviral therapy, and treatment variables as predictors of clinical outcomes.

RESULTS

One hundred ninety-seven patients received ganciclovir therapy. Nineteen patients developed phenotypic resistance to ganciclovir, and 18 developed genotypic resistance. The detection of cytomegalovirus resistant to ganciclovir was associated with a 4.17- to 5.61-fold increase in the odds of retinitis progression (P values all < or = .0002), depending upon the definition of resistance and the culture sources analyzed. Resistance was associated with a greater increase in retinal area involved by cytomegalovirus by 3-month interval (1.10% vs 0.05% to 0.10%), which was significant for phenotypic resistance and for genotypic resistance in the blood or urine (P =.012 to.021). There was a suggestion that resistance was associated with a greater loss of visual acuity (P =.009 to.096). Highly active antiretroviral therapy was associated with an approximate 50% reduction in the odds of retinitis progression, and the ganciclovir implant was associated with an approximate 60% reduction.

CONCLUSIONS

The detection of cytomegalovirus resistant to ganciclovir in either the blood or urine of a patient with cytomegalovirus retinitis is associated with an increased risk of adverse ocular outcomes.

Cytomegalovirus retinitis after initiation of highly active antiretroviral therapy in HIV infected patients: natural history and clinical predictors

PURPOSE

To characterize the natural course and clinical predictors of cytomegalovirus (CMV) retinitis in human immunodeficiency virus (HIV)-infected patients after initiation of highly active antiretroviral therapy (HAART).

METHODS

Retrospective analysis of 53 HIV-positive patients (73 eyes with CMV retinitis) treated with and without HAART. All participants continued to take anti-CMV therapy. Survival analysis was used to characterize the natural course of CMV retinitis. Proportional hazards analysis was performed to assess the correlation of the nine potential clinical predictors (baseline CD4 count, post-HAART CD4 count, post-HAART rise in CD4 count, baseline weight, post-HAART rise in weight, post-HAART percentage rise in weight, log of baseline HIV viral load, log of minimum post-HAART HIV viral load, and post-HAART log unit reduction in HIV viral load) with the duration of CMV retinitis remission.

RESULTS

Patients receiving HAART had a median CMV retinitis remission duration of 574 days (95% confidence interval, 336-NA) whereas those not receiving HAART had a median remission duration of 80.5 days (95% confidence interval, 28-NA; P < 0.001). Within the HAART-treated population, the minimal viral load reached after HAART was the only clinical predictor to demonstrate significance (P = 0.0075). Several other clinical predictors demonstrated borderline significance; however, this was most likely due to the high correlation of these variables with the minimum post-HAART viral load. A potential secondary clinical predictor identified was the post-HAART rise in CD4 count (P = 0.085).

CONCLUSION

With the introduction of HAART, HIV-infected patients have much longer remission durations from recurrent CMV retinitis. The minimum HIV viral load level reached after the initiation of HAART treatment appears to be more important than other clinical variables in the prediction of favorable CMV retinitis remission status. Furthermore, a rise in CD4 T-lymphocyte count by itself appears to be a less significant clinical predictor but may be useful in combination with the HIV viral load data. Selective discontinuation of anti-CMV therapy may be considered in patients with a favorable set of clinical predictors.

AIDS related opportunistic infections, going but not gone

It is now more than two decades since the AIDS epidemic began with a cluster of Pneumocystis carinii pneumonia (PCP) in a community of homosexual men. Since then, many other infections have been characterized as opportunistic infections secondary to HIV infection. These include, but are not limited to, infections with Toxoplasma gondii, Cytomegalovirus (CMV), Mycobacterium avium complex (MAC), and Cryptococcus neoformans. Over the last two decades, there have been dramatic improvements in diagnosis, prevention and treatment of all these infections. As a result, in North America and Western Europe the rates of opportunistic infections secondary to AIDS have decreased substantially. We will review these common opportunistic infections below.

A controlled trial of valganciclovir as induction therapy for cytomegalovirus retinitis

BACKGROUND

Valganciclovir is an orally administered prodrug that is rapidly hydrolyzed to ganciclovir. We compared the effects of oral valganciclovir with those of intravenous ganciclovir as induction therapy for newly diagnosed cytomegalovirus retinitis in 160 patients with the acquired immunodeficiency syndrome (AIDS).

METHODS

The primary end point was photographically determined progression of cytomegalovirus retinitis within four weeks after the initiation of treatment. Secondary end points included the achievement of a prospectively defined satisfactory response to induction therapy and the time to progression of cytomegalovirus retinitis. After four weeks, all patients received valganciclovir as maintenance therapy.

RESULTS

Eighty patients were randomly assigned to each treatment group. Of the patients who could be evaluated, 7 of 70 assigned to intravenous ganciclovir (10.0 percent) and 7 of 71 assigned to oral valganciclovir (9.9 percent) had progression of cytomegalovirus retinitis during the first four weeks (difference in proportions, 0.1 percentage point; 95 percent confidence interval, -9.7 to 10.0). Forty-seven of 61 patients (77.0 percent) assigned to intravenous ganciclovir and 46 of 64 (71.9 percent) assigned to valganciclovir had a satisfactory response to induction therapy (difference in proportions, 5.2 percentage points; 95 percent confidence interval, -20.4 to 10.1). The median times to progression of retinitis were 125 days in the group assigned to intravenous ganciclovir and 160 days in the group assigned to oral valganciclovir. The mean values for the area under the curve for the ganciclovir dosage interval were similar at both induction doses and maintenance doses. The frequency and severity of adverse events were similar in the two treatment groups.

CONCLUSIONS

Orally administered valganciclovir appears to be as effective as intravenous ganciclovir for induction treatment and is convenient and effective for the long-term management of cytomegalovirus retinitis in patients with AIDS.

Ophthalmic manifestations of HIV: an update

A variety of ocular disease processes have been identified in HIV-antibody positive persons, especially in people with AIDS. The most common sight-threatening disease in this population is cytomegalovirus (CMV) retinitis. Effective therapies are available to treat CMV retinitis. However, such therapies carry potentially challenging toxicities. Highly active antiretroviral therapy (HAART) has improved immune system functioning in many of its adherents, decreasing the incidence and improving the clinical course of CMV retinitis. However, a recent phenomenon associated with HAART, immune recovery uveitis (IRU), has been noted with additional, often problematic ocular manifestations in many persons with CMV retinitis. Periodic ophthalmic examination is prudent for all persons with HIV and especially for people with AIDS.

Contact dermatitis from topical antiviral drugs

The literature has been reviewed for contact dermatitis from topical antiviral drugs. 15 agents have been identified including acyclovir, imiquimod, podophyllin, podofilox, cidofovir, penciclovir, vidarabine, idoxuridine, trifluridine, tromantadine, lamivudine, interferon intralesional injections and ophthalmic solution, fomivirsen and foscarnet intravitreal injections and ganciclovir intraocular implants. Patch testing has been documented in certain individuals and cross-sensitization has been observed to contribute significantly to some allergic reactions.

Pharmacokinetics of the ganciclovir implant in the silicone-filled eye

PURPOSE

Ganciclovir (GCV) implants are highly effective in delaying the progression of cytomegalovirus (CMV) retinitis. Rhegmatogenous retinal detachments can occur in untreated eyes with CMV retinitis or in eyes treated with anti-CMV therapy, which may include placement of a GCV implant. The clinical management of CMV retinitis and associated retinal detachment often involves the concurrent use of silicone oil and GCV implants. The authors investigated the effect of silicone oil tamponade on intravitreal drug levels achieved with the GCV implant.

METHODS

The authors performed gas compression vitrectomy in the right eyes of 29 New Zealand white rabbits. They then inserted a 5-mg GCV implant into the vitreous cavity through an inferotemporal sclerotomy. Saline (1 cc), silicone oil 0.5 cc, or silicone oil 1.0 cc was then injected into the midvitreous cavity of 9, 8, and 12 rabbits, respectively. On postoperative days 21, 42, and 70, the rabbits were killed and the right eyes were immediately collected and stored at -70 degrees C until all samples were obtained. Vitreous was then isolated and drug levels were determined by high-pressure liquid chromatography.

RESULTS

Vitreous GCV levels at days 21 and 42 were similar in both the saline-filled and silicone oil-filled eyes. At day 70, GCV levels in both the saline- and silicone-filled eyes were statistically significantly lower than at day 21 (P < 0.05 for all groups). In addition, at day 70, GCV levels in the saline-filled eyes were significantly lower than in silicone-filled eyes (saline versus 0.5 cc oil, P = 0.01; saline versus 1 cc oil, P = 0.09).

CONCLUSIONS

Effective GCV levels are maintained in the aqueous phase of the vitreous cavity of eyes with silicone oil tamponade. Ganciclovir levels may be maintained longer in eyes with silicone oil tamponade than in those without. These results support the use of combined GCV implants and silicone oil tamponade in patients with CMV retinitis and associated retinal detachment.

Uveitis: what do we know and how does it help?

Uveitis essentially means intraocular inflammation and encompasses a wide variety of different disorders. This includes both mild and severe types of inflammation affecting different parts of the eye. Histologically, all uveitis is characterized by an influx of lymphocytes into the affected tissue. In all types these lymphocytes are predominantly of the CD4 type, whether the disorder is mild or blinding, giving no clue as to why. New studies comparing cells in ocular fluids taken from inflamed eyes with different types of inflammation have, for the first time, shown a difference in the cytokine profile, so that in visually benign disease interleukin 10 levels are higher than in those which are blinding.The potential for this in terms of therapy is discussed.

The ganciclovir implant plus oral ganciclovir versus parenteral cidofovir for the treatment of cytomegalovirus retinitis in patients with acquired immunodeficiency syndrome: The Ganciclovir Cidofovir Cytomegalovirus Retinitis Trial

PURPOSE

To compare the regimen of the ganciclovir implant plus oral ganciclovir to one of intravenous cidofovir for the treatment of cytomegalovirus retinitis.

METHODS

Sixty-one patients with acquired immunodeficiency syndrome and cytomegalovirus retinitis were randomized either to the regimen of the ganciclovir implant plus oral ganciclovir, 1 gm three times daily, or intravenous cidofovir, 5 mg/kg once weekly for two doses, followed by 5 mg/kg every other week.

RESULTS

Mortality was similar between the two treatment groups. Mortality rates were 0.41 per person-year in patients assigned to the ganciclovir regimen and 0.49 per person-year in patients assigned to cidofovir (P =.59). Ocular outcomes were similar between the two groups. Retinitis progression occurred at a rate of 0.67 per person-year in the ganciclovir group and 0.71 per person-year in the cidofovir group (P =.72). A loss of visual acuity of 15 letters or more occurred at a rate of 0.78 per person-year in the ganciclovir group and 0.47 per person-year in the cidofovir group (P =.28). The rate of loss of visual field was 7 degrees per month in the ganciclovir group and 2 degrees per month in the cidofovir group (P =.048). Vitreous hemorrhage was more common in the ganciclovir implant group (0.13 per person-year) than in the cidofovir group (no cases, P =.014), whereas uveitis appeared to be more common in the cidofovir group (0.35 per person-year) than in the ganciclovir group (0.09 per person-year, P =.066). Nephrotoxicity (serum creatinine 1.6 mg/dL or greater) occurred at a rate of 0.18 per person-year in the ganciclovir group and 0.48 per person-year in the cidofovir group (P =.10).

CONCLUSIONS

Although the small number of patients in this study limits definitive interpretation, these data suggest that in the era of highly active antiretroviral therapy, the regimens of the ganciclovir implant plus oral ganciclovir and of intravenous cidofovir are similar for controlling cytomegalovirus retinitis and preventing visual loss but have different side effects.

Biocompatibility and biodegradation of intravitreal hyaluronan implants in rabbits

To study the biocompatibility and the biodegradation rate in vivo of new intravitreal implants made with three different hyaluronic acid esters: Hyaff7, Hyaff11 and Hyaff11p75 (100% ethyl ester, 100 and 75% benzyl esters, respectively), the plugs were implanted through a sclerotomy at 3.5 mm from the limbus of rabbit eyes. In order to evaluate the in vivo biodegradation the shaft diameter of the plugs was measured by ultrasound biomicroscopy. Slit lamp microscopy, ophthalmoscopy and ERG were performed periodically. The effects of the implants on ocular tissues were also evaluated histologically. All the plugs showed a good biocompatibilitv. Plugs of both the total esters, Hyaff7 and Hyaff11, were found to undergo a slow dissolution process for 60 and 150 days, respectively. The partial benzyl ester, Hyaff11p75, was completely reabsorbed after 15 days. Analysis of variance showed a high correlation between biodegradation rate and the time of resorption (F = 90.5; p < 0.001). The biodegradation rate of each implant is related to the chemical structure of the three types of Hyaff (F = 4.51; p = 0.005). The present data suggest that intravitreal implants based on hyaluronic acid esters represent useful biocompatible and biodegradable devices for a potential drug delivery system in the treatment of posterior segment ocular diseases.

Incremental cost effectiveness of prophylaxis for cytomegalovirus disease in patients with AIDS

Cytomegalovirus (CMV) disease, an opportunistic complication in patients with AIDS, causes substantial morbidity and has high treatment costs. Although prevention of this disease is highly desirable, incremental cost-effectiveness estimates for proposed prophylactic strategies in the era prior to the availability of highly active antiretroviral therapy (HAART) were unfavourable relative to other specific antimicrobial prophylactic strategies in patients with AIDS. With the availability of HAART, several inputs upon which previous estimates of the incremental cost-effectiveness ratio for anti-CMV prophylaxis were based probably changed substantially. To assess the incremental cost effectiveness of prophylaxis in the HAART era, data are needed on visual outcomes and utility for patients with CMV retinitis and AIDS, on better strategies for identifying subpopulations at high risk for CMV disease and on the prophylactic efficacy of valganciclovir. Cost-effectiveness analysis could potentially contribute by exploring thresholds of population risk, prophylactic effectiveness, and drug pricing in order to identify conditions under which prophylaxis for CMV disease in patients with AIDS could potentially become cost effective.

Economic evaluation of systemic treatments for cytomegalovirus retinitis in patients with AIDS

OBJECTIVE

To determine the cost of using systemic therapy to treat newly diagnosed cytomegalovirus (CMV) retinitis in persons with AIDS.

DESIGN

Incidence-based simulation model of CMV treatment from a government payer perspective.

SETTING

Swiss healthcare system.

PATIENTS AND PARTICIPANTS

Patients with AIDS and newly diagnosed CMV retinitis.

INTERVENTIONS

Patients were assigned to 1 of 4 treatment regimens for induction and maintenance therapy: (i) intravenous (IV) cidofovir induction and maintenance (cidofovir IV/IV); (ii) IV foscarnet induction and maintenance (foscarnet IV/IV); (iii) IV ganciclovir induction and maintenance (ganciclovir IV/IV); and (iv) IV ganciclovir induction and oral (PO) ganciclovir maintenance (ganciclovir IV/PO). Following a second relapse, patients were assigned to one of the other regimens.

MAIN OUTCOME MEASURES

Time to first and subsequent progression, duration of maintenance treatment and direct medical expenditures [1998 Swiss francs (SwF)] .

RESULTS

The median time to first progression was longest for cidofovir IV/IV, followed by foscarnet IV/IV, ganciclovir IV/IV and ganciclovir IV/PO. Mean survival was 13 months and mean costs for this period in the base case were lowest in those initially treated with cidofovir (SwF146,742), followed by initial treatment with foscarnet IV/IV (SwF194,809), ganciclovir IV/PO (SwF195,190) and ganciclovir IV/IV (SwF243,964). Costs were most sensitive to changes in efficacy estimates.

CONCLUSIONS

Of the regimens studied, initiation of treatment with systemic cidofovir appears least costly over a 13-month period.

Management and Prevention of Opportunistic Infections in the HIV-Infected Patient

With the introduction of potent antiretroviral therapy, the incidence of opportunistic infections (OIs) as well as death has dramatically decreased since 1996. Opportunistic infections are seen mainly in three groups: (1) newly diagnosed patients not receiving antiretroviral therapy and presenting with an OI, (2) patients nonadherent to antiretroviral and OI treatment regimens or (3) patients whose antiretroviral therapy has failed. This article will review the most common opportunistic infections (OIs) seen in the HIV-infected individual and their treatment. The current guidelines for the prophylaxis against these OIs will also be discussed.

Immune recovery uveitis in patients with AIDS and cytomegalovirus retinitis after highly active antiretroviral therapy

PURPOSE

To estimate the incidence and describe the characteristics of immune recovery uveitis in patients with acquired immunodeficiency syndrome (AIDS) and cytomegalovirus retinitis treated with highly active antiretroviral therapy.

METHODS

The records of all patients with AIDS and cytomegalovirus retinitis from 1995 to 1998 seen at the AIDS Ophthalmology Service of the Johns Hopkins Medical Institutions were reviewed. Eighty-two patients with cytomegalovirus retinitis treated with highly active antiretroviral therapy were identified. Thirty-three patients (40.2%) were classified as responders to highly active antiretroviral therapy, defined as an increase in CD4+ T-cell count by 50 cells/microL or more to a level of 100 cells/microL or more.

RESULTS

Immune recovery uveitis occurred in six patients. Among the 33 patients with an immunologic response to highly active antiretroviral therapy, the incidence rate of immune recovery uveitis was 0.109/person-year. Ocular complications associated with immune recovery uveitis included cystoid macular edema (four patients), epiretinal membranes (two patients), and optic disk neovascularization (one patient).

CONCLUSIONS

Immune recovery uveitis was uncommon in our population but may have vision-impairing complications.

Biomaterials used in the posterior segment of the eye

The treatment of posterior segment eye disease and related conditions has improved greatly in recent years with the advent of new therapies, materials and devices. Vitreoretinal conditions, however, remain significant causes of blindness in the developed world. Biomaterials play a major role in the treatment of many of these disorders and the success rate of vitreoretinal surgery, especially in the repair of retinal detachment and related conditions, would increase with the introduction of new and improved materials. This review, which focuses on disorders that feature retinal detachment, briefly describes the anatomy of the eye and the nature and treatment of posterior segment eye disorders. The roles, required properties and suitability of the materials used in vitreoretinal surgery as scleral buckles, tamponade agents or drug delivery devices, are reviewed. Experimental approaches are discussed, along with the methods used for their evaluation, and future directions for biomaterial research in the posterior segment of the eye are considered.

Therapeutic developments in cytomegalovirus retinitis

The incidence of cytomegalovirus (CMV) retinitis in AIDS has declined significantly due to the use of highly active antiretroviral therapy (HAART). However, patients with HIV, especially those failing HAART, may still suffer with CMV retinitis, which can lead to significant loss of vision and blindness. Ganciclovir has traditionally been considered the recommended treatment for CMV retinitis; however, due to side effects and the possibility of developing viral resistance, other agents may be preferred in certain situations. Foscarnet, which has similar efficacy to ganciclovir but a different side effect profile, is more difficult to administer and is less well-tolerated. Intravenous cidofovir, which may be more effective than either iv. ganciclovir or foscarnet, can also be used as a first line agent; however, it is associated with toxicity (renal and ocular) and thus needs careful use. Local therapy for CMV retinitis has been a significant advance. The intraocular ganciclovir implant has the highest efficacy of the approved agents and is well-tolerated. Fomivirsen, an oligonucleotide injected intravitreally, is a newly approved agent which offers alternative treatment. Intravitreal ganciclovir or foscarnet, although not approved, have been used successfully in some patients especially those with recurrent or refractory disease. The development of new anti-CMV agents has been stalled by the decreased incidence of the disease. Valganciclovir, a prodrug of ganciclovir, offers excellent oral bioavailability and is the closest to approval of all the new anti-CMV drugs. High ganciclovir blood levels are achieved without the complications associated with the requirement for long-term iv. access. The monoclonal antibody (mAb) MSL-109, did not offer a significant advantage when added to traditional anti-CMV therapy. Development plans of other agents such as cyclic HPMPC and lobucavir have been put on hold by their respective manufacturers. Adefovir is a nucleotide analogue that possesses anti-CMV activity, but is currently only being pursued for the treatment of hepatitis B virus. Other compounds possessing significant anti-CMV activity, including BAY 38-4766 and GW1263W94 are still in the early stages of development.

Recent advances in the therapy and prevention of CMV infections

The introduction of highly active antiretroviral therapy (HAART) for HIV has had a major impact on the treatment of CMV disease in HIV-infected individuals. There is mounting evidence that in patients with CMV retinitis who have a sustained response to HAART, CMV maintenance treatment can be discontinued without relapse of retinitis. In HAART-naïve individuals with newly diagnosed CMV retinitis, the optimal timing for the initiation of HAART relative to the start of anti-CMV treatment is currently unknown. New local therapies for CMV retinitis (e.g. ganciclovir implant, the new antisense compound fomivirsen) provide treatment options in situations where high local drug delivery is warranted. A treatment algorithm for CMV disease in the HAART era is proposed. In the transplant setting, ganciclovir and foscarnet remain the major compounds used for treatment of CMV disease. In marrow and stem cell transplant recipients, CMV pneumonia still carries a high mortality. Ganciclovir in combination with CMV-specific immunoglobulin or regular intravenous IG remains the treatment of choice for CMV pneumonia; extended antiviral maintenance for several months is recommended in patients with continued immunosuppression. Preemptive treatment based on virologic markers (e.g. pp65 antigenemia, CMV DNA) has been very successful in reducing the incidence of early CMV disease in the transplant setting. The duration of preemptive treatment should be guided by the underlying immunosuppression and virologic markers. Late CMV disease is a challenge in marrow and stem cell transplant recipients, and occurs increasingly in highly immunosuppressed solid organ transplant recipients as well. Recent advances in prophylaxis strategies include oral ganciclovir for liver transplant recipients and valacyclovir for kidney transplant recipients.

Ocular manifestations of HIV infection

Ophthalmic abnormalities are common in HIV-infected patients. Serious ophthalmic diseases often result from opportunistic infections and can cause blindness in the absence of prompt diagnosis and therapy. We review recent advances in the diagnosis and management of HIV-associated ocular disease, including cytomegalovirus retinitis, the leading cause of vision loss in HIV-infected patients. The widespread use of highly active antiretroviral therapy (HAART) over the past 3 years has reduced the morbidity and mortality associated with HIV infection. HAART has dramatically altered the incidence and natural history of many opportunistic infections, and we discuss the impact of HAART on ophthalmic disease.

Development of novel benzimidazole riboside compounds for treatment of cytomegalovirus disease

Benzimidazole ribosides are a new class of compounds with novel mechanisms of action against CMV. One compound in this series, BDCRB, inhibits CMV DNA processing by the UL89 gene product (putative terminase), but rapid metabolism to an inactive compound makes it unsuitable for development as a medicine. Another benzimidazole analogue, 1263W94, has many characteristics that make it an attractive candidate for development, including high potency in vitro, selectivity, good oral bioavailability, and lower toxicity than therapies currently available for treatment of CMV disease. Initial clinical trials have provided encouraging results, including good tolerability and linear pharmacokinetics over a wide dose range. Ongoing and planned clinical trials that will study the safety and tolerability of repeated dosing and evaluate the in vivo antiviral activity and ocular penetration of 1263W94, will help to determine the potential of this drug as an improved therapy for CMV disease.