High dose intravitreal ganciclovir in the treatment of cytomegalovirus retinitis

High-dose (5000-μg) Intravitreal Ganciclovir Combined with Highly Active Antiretroviral Therapy for Cytomegalovirus Retinitis in HIV-Infected Patients in Venezuela

Purpose

To describe the use of high doses of intravitreal ganciclovir combined with highly active antiretroviral therapy (HAART) for the treatment of cytomegalovirus (CMV) retinitis in human immunodeficiency virus (HIV)-infected patients.

Methods

Thirteen HIV-infected patients (18 eyes) with active CMV retinitis (83.3% in zone 1 and 38.4% resistant) participated in this prospective interventional case series. Patients were treated with high dose intravitreal ganciclovir (5.0 mg/0.1 mL once a week) in combination with HAART therapy. Intravitreal injections were discontinued once CMV retinitis healed if there was a significant increase in CD4+ count (any increase of ≥50 cells/μL to levels over 100 cells/μL sustained for at least 3 months). Mean follow-up was 15.6 months. Main outcome measures included assessment of visual acuity and retinal inflammation (CMV retinitis activity). A matched historical control group of 20 eyes (15 patients) with CMV retinitis treated with systemic ganciclovir (intravenous [induction] and oral [maintenance]) was included.

Results

Complete regression of the retinitis was obtained with high doses of intravitreal ganciclovir in 88.8% of eyes (two patients died during follow-up) at a mean of 4.5 weeks (2 to 8 weeks). Visual acuity improved two or more lines in 61.1% of eyes. No ganciclovir retinal toxicity was identified. Three eyes presented CMV retinitis reactivation at a mean of 25.6 days after their last injection. Complications (33.3%) included retinal detachment (RD; 3 eyes), immune recovery uveitis (IRU; 2 eyes), and endophthalmitis (1 eye). In our control group complete regression of the retinitis was obtained in 100% of eyes at a mean of 4 weeks (3 to 7 weeks). However, 12 eyes (60%) presented with CMV retinitis relapse at a mean of 29 days (21 to 32 days) after initiating oral ganciclovir (maintenance). Complications included RD (7 eyes, 35%) and IRU (3 eyes, 15%). Severe neutropenia occurred in 2 patients (13%).

Conclusions

High doses of intravitreal ganciclovir (5.0 mg) once a week in combination with HAART therapy is effective to control CMV retinitis, and may be discontinued after CMV retinitis has healed if immune reconstitution with a significant increase in CD4+ count has occurred.

Treatment outcomes of reduced-dose intravitreal ganciclovir for cytomegalovirus retinitis

Background

Cytomegalovirus retinitis (CMVR) is one of the most common opportunistic infection in immunocompromised individuals. Intravitreal ganciclovir injection has been used successfully but no standard regimen was established. Risks of drug toxicity, endophthalmitis, and injection-related complications increased with number and frequency of injection. The aim of this study is to evaluate the outcomes of reduced-dose intravitreal ganciclovir (2 mg/0.04 mL) for the treatment of CMVR.

Methods

A prospective observational cohort study involving 67 eyes of 49 patients with CMVR was performed. Induction therapy involved intravenous ganciclovir (10 mg/kg/day) for 2 weeks unless contraindicated or patients refused. Patients were then treated with reduced-dose intravitreal ganciclovir every week for 4 weeks, and then every other week until the lesion healed. The patients’ demographic data were recorded, and vision parameters were examined every visit.

Results

Twenty eyes (29.9 %) presented with initial visual acuities less than 6/60. The majority of patients were diagnosed with CMVR in zones 1 or 2 (63 eyes, 94 %), and, at least, one quadrant of the retina was involved (56 eyes, 83.6 %). Forty-one eyes (61.2 %) completely resolved after treatment within the 6-month follow-up. There was no significant difference in healing time, whether or not patients received induction treatment with intravenous ganciclovir (111.00 ± 12.96 vs 105.00 ± 28.32 days, p = 0.8). Five eyes (12.2 %) of patients with healed CMVR had visual acuities less than 6/60.

Conclusions

Reduced-dose intravitreal ganciclovir is a safe and effective treatment option. It provides comparable results to other weekly regimens. Induction with intravenous ganciclovir is not crucial in a resolution of retinitis, although it may be necessary to reduce systemic cytomegalovirus loads and mortality rates.

Trial registration

The trial was registered with Thai Clinical Trials Registry (TCTR) on 16 March 2016 – TCTR20160316001.

Multiple intravitreal injections of ganciclovir for cytomegalovirus retinitis after stem-cell transplantation

BACKGROUND

Cytomegalovirus (CMV) infection is a major cause of morbidity and mortality in patients after hematopoietic stem cell transplantation (HSCT). Although much effort has been put into dealing with CMV retinitis secondary to acquired immunodeficiency syndrome (AIDS), the few reports which have been published have mainly focused on treatment of CMVR after HSCT.

METHODS

This clinical interventional retrospective study included 14 patients (eight men; mean age 23.89 ± 12.09; 23 eyes) who suffered from CMV retinitis after stem-cell transplantation, in order to evaluate the efficacy and safety of multiple intravitreal injections of ganciclovir (IVG) for patients with CMV retinitis. All patients received 4 injections of IVG of 1 mg at 1 week intervals, and were followed up weekly for at least 2 months with measurement of best-corrected visual acuity (BCVA) and CMV levels in anterior aqueous humor with real-time polymerase chain reaction. Anterior aqueous humor was obtained before each injection.

RESULTS

The levels of CMV in anterior aqueous humor showed significant decrease from (6.34 ± 15.78) × 10(5) copies/ml at baseline to (5.22 ± 12.15) × 10(3) copies/ml at 1 month (P < 0.001, Mann-Whitney U test). CMV couldn't be detected in 11 eyes (47.8 %) after two injections, and this rose to 18 eyes (78.3 %) at 1 month. The mean logMAR BCVA was 0.659 ± 0.572 at baseline and 0.680 ± 0.527 at 2 months, which suggested no significant improvement (P = 0.736, Mann-Whitney U test) during the procedure. All patients experienced improved vitreous opacity and diminished area of the lesion under funduscopy after 4 injections of IVG. No severe complications developed.

CONCLUSIONS

Multiple IVG seemed to be beneficial for patients with CMV retinitis after stem-cell transplantation, in reducing CMV levels in aqueous humor. Further study to optimize the dose of ganciclovir is needed in order to achieve better treatment outcomes.

Current and emerging antivirals for the treatment of cytomegalovirus (CMV) retinitis: an update on recent patents

Cytomegalovirus (CMV) retinitis is the most common ocular opportunistic complication and a serious cause of vision loss in immunocompromised patients. Even though, a rise in human immunodeficiency virus (HIV) infected individuals seems to be a major factor responsible for the prevalence of CMV retinitis, the introduction of highly active antiretroviral therapy (HAART) significantly reduced the incidence and severity of CMV retinitis. Thorough evaluation of the patient's immune status and an exact classification of the retinal lesions may provide better understanding of the disease etiology, which would be necessary for optimizing the treatment conditions. Current drugs such as ganciclovir, valganciclovir, cidofovir and foscarnet have been highly active against CMV, but prolonged therapy with these approved drugs is associated with dose-limiting toxicities thus limiting their utility. Moreover development of drug-resistant mutants has been observed particularly in patients with acquired immunodeficiency syndrome (AIDS). Continuous efforts by researchers in the industry and academia have led to the development of newer candidates with enhanced antiviral efficacy and apparently minimal side effects. These novel compounds can suppress viral replication and prevent reactivation in the target population. Though some of the novel therapeutics possess potent viral inhibitory activity, these compounds are still in stages of clinical development and yet to be approved. This review provides an overview of disease etiology, existing anti-CMV drugs, advances in emerging therapeutics in clinical development and related recent patents for the treatment of CMV retinitis.

Intravitreal ganciclovir maintenance injection for cytomegalovirus retinitis: efficacy of a low-volume, intermediate-dose regimen

OBJECTIVE

To report the clinical outcomes of highly active antiretroviral therapy (HAART)-naïve, human immunodeficiency virus (HIV)-positive patients with newly diagnosed cytomegalovirus (CMV) retinitis receiving intravitreal injections of a low-volume intermediate maintenance dose (1.0 mg/0.02 ml) of ganciclovir.

DESIGN

Nonrandomized, retrospective, interventional series.

PARTICIPANTS

A consecutive cohort of 34 eyes from 24 HAART-naïve patients with AIDS and diagnosed with CMV retinitis by retinal specialists at the Singapore Communicable Disease Centre.

INTERVENTION

Patients received a maintenance dose of 1.0 mg/0.02 ml of intravitreal ganciclovir once weekly after standard induction therapy with 2.0 mg/0.04 ml of twice weekly intravitreal ganciclovir.

MAIN OUTCOME MEASURES

Time to progression, visual acuity, and complications. Progression was observed using photographic documentation.

RESULTS

The median time to progression was 152 days (mean, 380.1 days, 95% confidence interval, 240.8-519.4). The median follow-up was 95 days (mean, 207.9 days). Three eyes developed rhegmatogenous detachments, but there was no endophthalmitis after 1858 injections. Contralateral involvement of CMV retinitis occurred in 17.6% of the patients. The cost estimate for intravitreal injections over a 6-month period was 11.7% that of sustained-release implants for unilateral treatment and 11.1% that of daily continuous intravenous infusions and oral valganciclovir compared with bilateral treatments.

CONCLUSIONS

Weekly low-volume, intermediate-dose (1.0 mg/0.02 ml) ganciclovir is an efficacious option in developing countries where newer options of sustained-release implants and oral valganciclovir are unavailable or prohibitively expensive. The regimen maintains a long time to progression, preserving vision while minimizing retinal toxicity complications.

Optimal management of cytomegalovirus retinitis in patients with AIDS

Cytomegalovirus (CMV) retinitis is the most common cause of vision loss in patients with acquired immunodeficiency syndrome (AIDS). CMV retinitis afflicted 25% to 42% of AIDS patients in the pre-highly active antiretroviral therapy (HAART) era, with most vision loss due to macula-involving retinitis or retinal detachment. The introduction of HAART significantly decreased the incidence and severity of CMV retinitis. Optimal treatment of CMV retinitis requires a thorough evaluation of the patient's immune status and an accurate classification of the retinal lesions. When retinitis is diagnosed, HAART therapy should be started or improved, and anti-CMV therapy with oral valganciclovir, intravenous ganciclovir, foscarnet, or cidofovir should be administered. Selected patients, especially those with zone 1 retinitis, may receive intravitreal drug injections or surgical implantation of a sustained-release ganciclovir reservoir. Effective anti-CMV therapy coupled with HAART significantly decreases the incidence of vision loss and improves patient survival. Immune recovery uveitis and retinal detachments are important causes of moderate to severe loss of vision. Compared with the early years of the AIDS epidemic, the treatment emphasis in the post- HAART era has changed from short-term control of retinitis to long-term preservation of vision. Developing countries face shortages of health care professionals and inadequate supplies of anti-CMV and anti-HIV medications. Intravitreal ganciclovir injections may be the most cost effective strategy to treat CMV retinitis in these areas.

Incidence of endophthalmitis related to intravitreal injection of bevacizumab and ranibizumab

PURPOSE

To report the overall incidence of endophthalmitis associated with office based intravitreal injections of bevacizumab and ranibizumab.

METHODS

This is a retrospective, consecutive, multicenter case series involving four large clinical sites. Included were all patients receiving at least one injection of intravitreal bevacizumab or intravitreal ranibizumab. Follow-up after each injection was at least 4 weeks.

RESULTS

A total of 12,585 injections of intravitreal bevacizumab and 14,320 injections of intravitreal ranibizumab were given during the study period. Infectious endophthalmitis developed in three patients after administration of bevacizumab and in three patients after administration of ranibizumab. Four of these patients were culture positive. Rates of endophthalmitis were 0.02% and 0.02%, respectively, with an overall rate of 0.02%.

CONCLUSION

The rate of endophthalmitis associated with intravitreal bevacizumab and ranibizumab is low, with an incidence of approximately 1 in 4,500 injections.

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.

RISKS OF INTRAVITREOUS INJECTION: A COMPREHENSIVE REVIEW

PURPOSE

To evaluate the prevalence of the most common serious adverse events associated with intravitreous (IVT) injection.

METHODS

A systematic search of the literature via PubMed from 1966 to March 1, 2004, was conducted to identify studies evaluating the safety of IVT injection. Data submitted in New Drug Applications to the U.S. Food and Drug Administration for drugs administered into the vitreous were included where available. Serious adverse events reported in each study were recorded, and risk per eye and risk per injection were calculated for the following serious adverse events: endophthalmitis, retinal detachment, iritis/uveitis, intraocular hemorrhage, ocular hypertension, cataract, and hypotony. Rare complications also were noted.

RESULTS

Data from 14,866 IVT injections in 4,382 eyes were analyzed. There were 38 cases of endophthalmitis (including those reported as pseudoendophthalmitis) for a prevalence of 0.3% per injection and 0.9% per eye. Excluding cases reported specifically as pseudoendophthalmitis, the prevalence of endophthalmitis was 0.2% per injection and 0.5% per eye. Retinal detachment, iritis/uveitis, ocular hypertension, cataract, intraocular hemorrhage, and hypotony were generally associated with IVT injection of specific compounds and were infrequently attributed by the investigators to the injection procedure itself. Retinal vascular occlusions were described rarely in patients after IVT injection, and it was unclear in most cases whether these represented true injection-related complications or chance associations.

CONCLUSION

The risk of serious adverse events reported after IVT injection is low. Nevertheless, careful attention to injection technique and appropriate postinjection monitoring are essential because uncommon injection-related complications may be associated with permanent vision loss.

High-dose intravitreal ganciclovir and foscarnet for cytomegalovirus retinitis

PURPOSE

To describe the chronic use of high doses of intravitreal ganciclovir, in combination with foscarnet, for the treatment of cytomegalovirus retinitis.

METHODS

A 31-year-old man with human immunodeficiency virus (HIV) infection and unilateral active cytomegalovirus retinitis was treated with escalating intravitreal injections of ganciclovir (up to 3.0 mg twice a week) in combination with foscarnet (up to 2.4 mg twice a week) over the course of approximately 1 year.

RESULTS

Complete regression of the retinitis was obtained with high doses of intravitreal ganciclovir and foscarnet. Visual acuity in the affected eye remained 20/20 throughout the course of therapy. No ganciclovir retinal toxicity was identified.

CONCLUSION

High doses of intravitreal ganciclovir in combination with foscarnet can be well tolerated and may be required to successfully control cytomegalovirus retinitis in some patients.

Etoposide as a virocidal anticytomegalovirus therapy: intravitreal toxicology and pharmacology in rabbits

BACKGROUND

Although Cytomegalovirus (CMV) retinitis is now a common intraocular infection, current therapy is only virostatic so ongoing treatment is required. Etoposide was found to be virocidal for CMV in laboratory experiments and it might prove to be beneficial clinically. We investigated the toxicity and intraocular concentration of etoposide (VP16) and its new analogue etoposide-phosphate (VP16P) following intravitreal injections in rabbit eyes.

METHODS

First a sequential dose-response was assessed with flash electroretinogram for both eyes of light- and dark-adapted rabbits (n = 7; one rabbit for each dose) over a range of light intensities before and after intravitreal injection of VP16 or VP16P to one eye; the other eye was injected with normal saline as a control. A multidose study was then performed on four rabbits. A non-toxic dose of VP16P (50 or 75 g) was injected into the vitreous of one eye on four occasions 1 week apart. A photopic electroretinogram was performed before the first injection and 6 weeks after the last injection. All the eyes from the electroretinogram studies were fixed in formalin, placed in paraffin, then stained with haematoxylin and eosin and examined under a light microscope. To determine the time-course of the intraocular concentrations of VP16P a sequential pharmacokinetic study was performed using a further 12 rabbits. Each rabbit was injected with 50 g VP16P to one eye and 75 g VP16P to the other eye. Three of these rabbits were killed at 1, 3, 6 and 9 h after injection. Samples of vitreous were assayed for both VP16 and VP16P using HPLC. An in vitro dose response assay was performed using third-passage bovine retinal pigment epithelial (RPE) cells cultured in Dulbecco's modified Eagles medium with fetal calf serum. The effect of a log-dose increment of VP16P on the RPE cell proliferation was assessed using tritiated thymidine incorporation.

RESULTS

The electroretinogram studies suggested that VP16 was toxic even with the 10 g dose. For VP16P a toxic effect was noted following injection of a single dose greater than 100 g. Multiple injections of 50 or 75 g VP16P did not produce a toxic response. Histological examination demonstrated significant abnormality only with the 500 g dose of VP16 or VP16P. VP16P was rapidly metabolized to VP16 in the eye, producing concentrations of 2.0 g/mL or more for up to 9 h following a 75-microg dose. This suggests that the electroretinogram findings following VP16 injections were confounded by a toxic effect of the ethanol solvent (which is absent from the VP16P preparation). VP16P was quite potent, the ID50 was about 0.1 g/mL for bovine RPE cells in the in vitro assay.

DISCUSSION

These results indicate that multiple 75-gVP16P intravitreal injections were not toxic to the rabbit eye and provide a therapeutic intraocular concentration for up to 9 h after the injection.

Virus infections of the eye

In reviewing the clinical features, diagnostic evaluations and therapies of the most common ocular viral infections we attempt to whet your appetite for attacking the numerous challenges in diagnosis and treatment of viral eye disease. The herpes viruses, HSV, VZV and CMV are the cause of significant ocular morbidity. HSV most commonly affects the cornea producing keratitis that can be recurrent and may lead to corneal clouding and neovascularisation. Manifestations can be purely infectious or immunological and treatment options must be tailored to the underlying pathophysiology. Herpes zoster ophthalmicus, caused by VZV infection of the first branch of the trigeminal nerve, produces a characteristic rash and can progress to keratitis and uveitis. HSV and VZV can cause retinitis in both immunocompetent and immunocompromised individuals. There has been a significant increase in the incidence of CMV retinitis since the beginning of the AIDS epidemic. We review the numerous new treatments, diagnostic tests and treatment strategies which have been developed in response to this potentially blinding retinal infection. Adenovirus produces an epidemic conjunctivitis and epidemic keratoconjunctivitis which are severe and extremely contagious conjunctival infections. HIV, molluscum contagiosum, EBV and rubeola also cause ocular diseases which are described.Copyright 1998 John Wiley & Sons, Ltd.

High-dose (2000-microgram) intravitreous ganciclovir in the treatment of cytomegalovirus retinitis

OBJECTIVE

The authors prospectively studied visual outcome, relapse, complications, and survival of patients with acquired immune deficiency syndrome (AIDS)-related cytomegalovirus (CMV) treated with high-dose intravitreous ganciclovir (2 mg/0.1 ml) injections. The outcomes were compared with those of patients treated with standard doses of intravenous ganciclovir in the same institution. The histopathologic and electrophysiologic effects of high-dose intravitreous ganciclovir injections in rabbits also were studied.

DESIGN

A nonrandomized case series.

PARTICIPANTS

A total of 42 patients (74 eyes) were treated with intravitreous injections and 18 patients (27 eyes) were treated with intravenous ganciclovir. Five eyes of three New Zealand white rabbits were injected with ganciclovir, and the sixth eye was a control specimen.

INTERVENTION

Patients treated with intravitreous injections received twice-weekly doses of 2 mg/0.1 ml ganciclovir for 3 weeks, then weekly injections. Patients treated with intravenous ganciclovir received standard doses. Patients were monitored with regular examinations. Rabbit eyes were given intravitreous injections of 1 mg/0.1 ml of ganciclovir weekly for 4 weeks.

MAIN OUTCOME MEASURES

Assessments of vision, retinal inflammation, and survival were made. Electroretinograms were performed on the rabbit eyes, and they were processed for light and electron microscopy.

RESULTS

In the intravitreous group, visual acuity (VA) was stable in 64 of 74 eyes, 5 improved, and 5 deteriorated. Sixty-three (85%) of 74 eyes had final VA of 20/20 to 20/40. Relapse occurred in five eyes (7%; median time, 42 weeks). There were three cases of endophthalmitis. Median survival after diagnosis of CMV retinitis was 36 weeks. In the intravenous group, VA was stable in 18 eyes, 0 improved, and 9 deteriorated. Sixteen (59%) of 27 eyes had final VA of 20/20 to 20/40. Relapse occurred in 15 eyes (56%) at a median time of 21 weeks. Median survival was 21 weeks. The rabbit studies showed no evidence of toxicity.

CONCLUSION

High-dose intravitreous ganciclovir effectively suppressed CMV retinitis, preserved vision, and prevented relapse without deterioration in survival.

New therapeutic options in uveitis

Most patients with sight-threatening posterior uveitis eventually end up on systemic medication to control their disease. Although the more aggressive approach to the use of these drugs does offer the patient a better chance of significant visual improvement at least in the short term, this is often associated with severe systemic side-effects in both the young and older patient. Cyclosporin has become a very useful second-line agent as a steroid sparer in those patients who can tolerate it. However, it is not suitable for or effective in everyone and the other currently available drugs are often of limited effectivity or associated with major systemic sequelae. This paper summarises the therapeutic approaches currently being examined to define whether they have a role in the better management of these patients in the future. Particularly exciting is the potential for sustained intraocular drug delivery so that adequate drug levels are achieved inside the eye without the necessity for systemic administration.

Local therapy for cytomegalovirus retinitis

OBJECTIVE

To examine the role of intraocular therapy in the management of cytomegalovirus (CMV) retinitis associated with AIDS.

DATA SOURCES

A MEDLINE search was conducted for the years 1980-1997. In addition, relevant articles were cross-referenced to screen for additional information. The AIDS/HIV Treatment Directory was searched for information on ongoing studies.

STUDY SELECTION/DATA EXTRACTION

Data regarding the use of local antiviral therapy for CMV retinitis are cited. Emphasis was placed on randomized, controlled trials, but descriptive studies are also included.

DATA SYNTHESIS

Intraocular drug administration is an alternative therapy for CMV retinitis that avoids some of the disadvantages associated with systemic treatment. Intravitreal ganciclovir 200-2000 micrograms once weekly has been studied in a number of nonrandomized studies. Although initially effective, intravitreal ganciclovir is associated with a significant relapse rate and development of contralateral CMV retinitis. Intraocular ganciclovir implants offer the advantage of less frequent interventions and constant drug concentrations in the vitreous. Time to progression is significantly longer in patients receiving implants versus intravenous therapy; however, there is a higher incidence of contralateral eye retinitis and extraocular CMV disease with the implants. Currently, the intraocular implant is being studied in combination with oral ganciclovir to decrease the incidence of systemic CMV disease. Foscarnet and cidofovir have also been administered intravitreally for CMV retinitis. Cidofovir may offer the advantage of a long intracellular half-life, which would allow infrequent dosing; however, further study is needed to determine a safe and effective intraocular dosage.

CONCLUSIONS

Systemic therapy continues as standard management for CMV retinitis. Local therapy has some advantages and disadvantages, but larger, randomized, controlled trials comparing systemic therapy with local therapy must be completed to define its exact role. Data from an ongoing trial of local plus oral therapy will better define this role.

Therapeutic options for resistant cytomegalovirus retinitis

Untreated cytomegalovirus (CMV) retinitis is progressive and generally leads to blindness within 6 months. Intravenous (i.v.) therapies such as foscarnet and ganciclovir, which were the first agents approved for the treatment of CMV retinitis, are effective in suppressing CMV replication, but they delay rather than prevent reactivation of CMV infection resulting in relapse of the disease. Furthermore, studies have shown that the time between subsequent reactivations becomes shorter, with each relapse producing more serious disease that may be more difficult to manage. This clinical failure may be caused in part by drug resistance; approximately 10% of all patients receiving systemic treatment with these agents may harbor drug-resistant viral strains. With three systemic therapies (ganciclovir, foscarnet, and cidofovir) now available for the treatment of CMV retinitis, several options exist for patients who have failed therapy with one of these drugs: reinduction with the same i.v. agent, switching therapies, or combining therapies. Resistant or relapsing CMV retinitis may also be treated by local therapies such as intraocular injections of ganciclovir and foscarnet or with a sustained-release ganciclovir implant. However, local therapy is ineffective in controlling extraocular or fellow eye CMV disease. It is likely that the integration of both local and systemic therapies will be required to halt the relentless progression of this debilitating disease, particularly when clinical resistance is encountered.

Cytomegalovirus antigenemia in acquired immunodeficiency syndrome patients with untreated cytomegalovirus retinitis

PURPOSE

To determine the frequency of cytomegalovirus (CMV) viremia in patients with acquired immunodeficiency syndrome (AIDS) and untreated CMV retinitis using conventional cell culture isolation and the sensitive CMV antigenemia assay.

METHODS

We examined 24 AIDS patients with ophthalmologic diagnosis of untreated CMV retinitis and 24 AIDS patients without present or past retinitis (control patients) from three medical centers between September 1992 and March 1994. Cytomegalovirus antigenemia was detected by an indirect peroxidase staining in 300,000 cytocentrifuged neutrophils, using a mixture of murine monoclonal antibodies directed against the pp65 lower matrix protein of CMV.

RESULTS

Positive antigenemia was demonstrated in eight (33.3%) of the 24 retinitis patients and in none of the 24 control patients (P < .001). Only two of the eight antigenemia-positive patients had a concurrent positive CMV isolation from blood leukocytes by conventional cell culture assay.

CONCLUSIONS

These results emphasize the risk of extraocular disease in AIDS patients with CMV retinitis because the virus is often present in peripheral blood leukocytes. The CMV antigenemia assay may be a simple and rapid means of identifying those patients with unilateral retinitis at highest risk of developing CMV retinitis of the fellow eye or of visceral CMV disease if intravitreal injections or implants are used as sole treatment for CMV retinitis.

Ophthalmic complications of HIV infection

HIV retinopathy, a noninfectious microangiopathy, is the most common ocular manifestation of HIV infection. Opportunistic infections, neoplasms, neuro-ophthalmic lesions, and drug-induced lesions may also cause ocular problems. Opportunistic ocular infections, particularly CMV retinitis, are a major cause of morbidity in patients with AIDS. Because of the underlying chronic and progressive immune dysfunction, the ocular symptoms, signs, clinical course, and treatment are often atypical and severe, requiring protracted medical therapy.

Intravitreal ganciclovir for cytomegalovirus retinitis in patients with AIDS

OBJECTIVE

To assess the evolution of cytomegalovirus (CMV) retinitis and evaluate the possible complications associated with the use of intravitreal injections to treat this disease.

DESIGN

A nonrandomized, retrospective study with case series was performed. The study took place over 34 months.

SETTING

The study included patients with AIDS who developed CMV retinitis, and who were treated in the hospital, as outpatients, or both.

PATIENTS

Twelve patients with AIDS and CMV retinitis diagnosed between June 1990 through April 1993 were included in the study. MAIN PATIENT PARAMETERS AND OUTCOME MEASURES: For each patient, the following data were recorded: age, risk factors, other systemic findings, dates of AIDS and CMV retinitis diagnoses, stage of AIDS, extent of the retinitis, CD4 lymphocyte count at the time of diagnosis of retinitis, visual acuity, clinical evolution of the ocular infection, therapy, complications caused by the treatment, development on nonocular CMV, and the use of zidovudine or didanosine during the study period.

RESULTS

Vision improved or remained stable in nine patients and worsened in three. Two patients developed optic neuritis. The retinitis progressed to the other eye in only one of the eight patients who had unilateral involvement. The rate of relapse with maintenance therapy was 8.3% (n = 1) within the first 8 weeks. Treatment was well tolerated. There was no evidence of toxicity after a total of 226 intravitreal ganciclovir injections. All patients were able to tolerate zidovudine or didanosine concomitantly with intravitreal ganciclovir.

CONCLUSIONS

Intravitreal ganciclovir appears to be an effective alternate to systemic ganciclovir in patients with severe neutropenia and in patients who choose to continue receiving systemic zidovudine or didanosine. Early treatment and long-term maintenance therapy is essential for preserving sight.

High dose intravitreal ganciclovir injection provides a prolonged therapeutic intraocular concentration

BACKGROUND

Although intravitreal high dose ganciclovir has previously been found to provide excellent control of cytomegalovirus (CMV) retinitis, little was known about the vitreous concentrations of ganciclovir after a 2 mg intravitreal injection.

METHODS

Eleven vitreous samples were taken from seven patients with CMV retinitis at 24 and 72 hours after a 2 mg intravitreal injection of ganciclovir and the concentration of ganciclovir was measured by high performance liquid chromatography.

RESULTS

The mean concentration of ganciclovir at 24 hours was 143.8 mg/l (95% confidence interval 97.8-190) and at 72 hours was 23.4 mg/l (95% CI 0-49.7). The half life ranged from 11.9 to 26.3 (mean 18.8) hours in the four patients who had two samples taken. The mean half life calculated from the mean concentrations at 24 and 72 hours was 18.3 hours, so the calculated mean concentration at 7 days was 0.6 mg/l.

CONCLUSIONS

This suggests that it takes about 7 days to eliminate the intravitreal ganciclovir, and that it is not likely to accumulate with weekly injections. The intravitreal concentrations achieved with high dose therapy remained above the ID50 for CMV (0.25-1.22 mg/l) for up to 7 days.

A foveal-sparing pattern of cytomegalovirus retinitis in the acquired immunodeficiency syndrome

PURPOSE

We describe the clinical course of 12 eyes of 10 patients in whom recurrent cytomegalovirus (CMV) retinitis exhibited a foveal-sparing pattern.

METHODS

We retrospectively reviewed the case records and photographic charts of 10 patients (12 eyes) with the acquired immunodeficiency syndrome (AIDS), in whom recurrent CMV retinitis exhibited a foveal-sparing pattern within 1500 mm of the foveola.

RESULTS

The site of primary retinitis was temporal in 10 eyes of nine patients in whom it was known. The median number of recurrences up to the observation of foveal-sparing retinitis was two (range one to eight), and five patients had active CMV retinitis despite treatment for at least two continuous months. Once established, the median rate of progression in a non-foveal vector was 2.3 times faster than toward the fovea, and the median time to reduction in acuity to < 6/30 (or death) was 11 to 14 weeks. Three eyes of three patients retained 6/30 or better acuity up to death. Foveal CMV retinitis ultimately reduced acuity to < 6/30 in five eyes. Six eyes suffered retinal detachment, involving the fovea in five, and being the primary reason for acuity of < 6/30 in four. Four patients suffered dose-limiting toxicity.

CONCLUSION

Foveal-sparing CMV retinitis arises in patients with recurrent CMV retinitis resistant to treatment ('clinically resistant'), particularly that which has arisen temporally. Despite its foveolar proximity, and ultimate significant loss of function, the pattern of progression allows for preservation of useful foveal vision for longer periods than would have been expected.

AIDS and the eye. A 10-year experience

BACKGROUND

The AIDS database at Fairfield Hospital, Melbourne, maintains information on eye pathology as identified by the three visiting ophthalmologists. Patients underwent an eye consultation: if they had ocular symptoms; if signs were seen on direct ophthalmoscopy by physicians; or when their CD4+ve cell count fell below 50/microL. The first AIDS-associated eye signs were identified in mid-1984. In the subsequent decade, 3257 patients in Victoria tested positive for HIV, and 845 of the 1123 who developed AIDS were treated at Fairfield Hospital.

METHODS

We undertook a retrospective review of the Fairfield Hospital database to identify the AIDS-associated ocular problems seen.

RESULTS

Some 723 patients had an eye consultation. In the earliest stage of HIV infection, minor non-specific ophthalmic involvement may occur. As the disease progresses, microvasculopathy (cottonwool spots and haemorrhages) appears. External disease also occurs such as molluscum contagiosum and Kaposi's sarcoma of the conjunctiva. With more suppression of the immune system, opportunistic infections become common, and have a considerable visual morbidity. Cerebral toxoplasmosis (117 patients) is only rarely associated with ocular involvement (three patients), but cytomegalovirus (CMV) commonly causes retinitis [204 patients (24%)]. It has been the AIDS-defining illness in 26 patients. A majority had the disease confined to one eye. Mean CD4 cell count at onset is 15 +/- 5 microL and it has been associated with a viraemia in all but two patients. Late complications of CMV retinitis include relapse in 41 (20%), spread to the other eye in 24 (12%), and retinal detachment in 30 (15%). Visual impairment follows from retinal destruction, optic nerve involvement, and retinal detachment.

CONCLUSION

The ophthalmic workload from late ocular complications of AIDS is increasing. Newer and more effective methods of treatment are being developed. Ophthalmologists are becoming more aware of the need for universal precautions to avoid risks from this and other blood-borne infections.

Cytomegalovirus retinitis in patients with AIDS: current status

About 20%-30% of patients with AIDS will develop cytomegalovirus (CMV) retinitis when they are severely immunodeficient (CD4 cell count below 40 cells/microL). It causes extensive retinal damage with visual deficits, and relapses are frequent. Intravenous ganciclovir and foscarnet are standard therapy, but their high toxicity and long term intravenous access mean that advances in treatment, including oral prophylactic agents, intravitreal injections and surgical implants, may provide a better quality of life for patients. Prophylactic ophthalmological screening of patients with CD4 cell counts below 100 cells/microL to detect asymptomatic retinitis is needed.

Local therapy for cytomegalovirus retinopathy

PURPOSE

We sought to understand better the efficacy and risks of local therapies (direct placement of drug into the eye) for the treatment of cytomegalovirus retinopathy. This understanding can be used to design rational treatment regimens, to formulate indications for use of local therapy, and to establish criteria for assessment of future results in this area.

METHODS

We collected information about local therapies through a review of published literature.

RESULTS

Intraocular injection of ganciclovir and foscarnet and implantation of intraocular devices that slowly release ganciclovir are able to decrease the activity of cytomegalovirus retinopathy lesions and prevent their enlargement for variable periods of time. The time to disease progression (lesion enlargement) may be longer with intraocular devices than with current treatments using intravenously administered antiviral drugs. Local therapies have many advantages (for example, convenience, reduced cost, and lack of systemic toxicity), but there are potential disadvantages, including endophthalmitis, increased rates of retinal detachment, and development of nonocular cytomegalovirus disease and cytomegalovirus retinopathy in fellow, uninvolved eyes.

CONCLUSIONS

Local therapies are effective for the treatment of cytomegalovirus retinopathy, but their relative risks and benefits, when compared with those of intravenous drug therapy, have yet to be fully evaluated. We anticipate that local therapy will be an important treatment modality for selected patients with cytomegalovirus retinopathy. Indications include the use of local therapy as an alternative therapy for patients who are unable to receive systemic therapy (intolerance to intravenous or oral medication, or lack of intravenous access) and as supplementation in patients whose retinal disease is incompletely controlled by maximum tolerated systemic medications. The use of local therapy as sole initial treatment in lieu of systemic therapy remains controversial. Its most useful role may be in conjunction with oral forms of antiviral drugs now in development.

High dose intravitreal ganciclovir for CMV retinitis: a shelf life and cost comparison study

BACKGROUND

It was previously found that high dose intravitreal ganciclovir provided superior treatment of cytomegalovirus retinitis compared with intravenous treatment. This study examined the stability and solubility of the ganciclovir solution to determine the shelf life of prepared solution, and compared the cost of intravitreal with intravenous therapy.

METHODS

For the solubility studies high performance liquid chromatography was used to determine the ganciclovir concentration in various solutions. Measurements were taken of freshly made 20 mg/ml solution, the same solution stored at room temperature or frozen for 10, 17, and 24 days, after the solution was filtered, and after it was heated at 56 degrees C. For the cost comparison analysis the cost of 22 patients treated exclusively with intravitreal high dose ganciclovir was compared with cost estimates for the same patients treated with a standard intravenous therapy regimen over the same time.

RESULTS

There was little variation in the concentration of ganciclovir regardless of the storage conditions, suggesting that the 20 mg/ml solution was very stable. The heating and filtering experiments suggest that maximum solubility was achieved both in the freshly prepared and thawed frozen stored solution. The total cost of the intravitreal treatment was Aus $172,435 and the estimate of intravenous treatment was Aus $490,521. This represents a total saving of $318,086 (65%), or $14,458 per patient. The average number of weeks of treatment for each patient was 27.9 (613 weeks/22 patients), so the saving per patient per year was $29,946.

CONCLUSION

High dose intravitreal ganciclovir therapy may be administered in a very cost effective way, which along with its acceptability, safety, and clinical efficacy make it an attractive method of treatment of CMV retinitis.

Prevention of intraocular pressure rise following intravitreal injection

The intraocular pressure change produced by an intravitreal injection of ganciclovir, 2 mg in 0.1 ml, was studied in patients with cytomegalovirus retinitis. Using a Tono-pen XL to measure the intraocular pressure (IOP) of four patients (six eyes) we found the mean pressure immediately following injection was 44.5 mm Hg. Measurements taken on separate occasions after a 30 mm Hg decompression of the eye for 15 minutes before the injection showed a mean IOP of only 20.6 mm Hg after the injection. Mercury bag decompression of the eye significantly reduced the rise in IOP following intravitreal injection (difference in the mean IOP rise = 26.4 mm Hg, df = 54, t = 7.67, p < 0.001). Without ocular decompression before injection, all patients complained of temporary loss of vision, and reflux of the injection solution was frequently observed. Use of ocular decompression also reduced the discomfort of the injection. Throughout the full course of treatment by this means there were no adverse effects on the visual acuity. This technique is recommended to those performing intravitreal injections.