Use of the ganciclovir implant in the treatment of recurrent cytomegalovirus retinitis

Long-acting ocular drug delivery technologies with clinical precedent

INTRODUCTION

Ocular long-acting injectables and implants (LAIIs) deliver drug at a controlled release rate over weeks to years. A reduced dose frequency eases the treatment burden on patients, minimizes the potential for treatment-related adverse effects, and improves treatment adherence and persistence.

AREAS COVERED

This review provides a comprehensive landscape of ocular LAII drug delivery technologies with clinical precedent, including eight commercial products and 27 clinical programs. Analysis of this landscape, and the specific technologies with the greatest precedent, provides instructive lessons for researchers interested in this space and insights into the direction of the field.

EXPERT OPINION

Further technological advancement is required to create biodegradable LAIIs with extended release durations and LAIIs that are compatible with a broader array of therapeutic modalities. In the future, ocular LAII innovations can be applied to diseases with limited treatment options, prophylactic treatment at earlier stages of disease, and cost-effective treatment of ocular diseases in global health settings.

CMV retinopathy in the antiretroviral therapy era: prevention, diagnosis, and management

Before the advent of antiretroviral therapy (ART), CMV retinitis was a common, debilitating opportunistic infection in the HIV-infected population. ART has had such a favorable impact on the prevention and management of CMV retinitis that it can be considered in some ways to be CMV therapy. Currently available CMV directed antiviral therapies are quite successful at limiting vision loss, but in resource limited settings there is still significant morbidity associated with the disease. This review summarizes the pathology, diagnosis, clinical course and treatment of retinitis in the pre-ART era to provide context for the contemporary clinical scenario, and highlights current management strategies. Important questions concerning host correlates of susceptibility and ideal therapy in the context of drug resistance are also briefly reviewed.

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.

Antimicrobial therapy for the treatment of opportunistic infections in HIV/AIDS patients: a critical appraisal

The widespread use of antiretroviral therapy (ART) has entirely changed the management of human immunodeficiency virus (HIV) infection and dramatically reduced the rates of opportunistic infections (OI). However, OI continue to cause significant morbidity and mortality in both developed countries, where presentation with advanced HIV infection is common, and also in developing countries where ART is less widely available. Evidence to direct OI guidelines is partly limited by the fact that many large-scale studies date from the pre-ART era and more recent studies are sometimes poorly powered due to the falling rates of OI. Treatment of OI is now known to be as much about antimicrobials as about immune reconstitution with ART, and recent studies help guide the timing of initiation of ART in different infections. OI have also become complicated by the immune reconstitution inflammatory syndrome phenomenon which may occur once successful immune recovery begins. Trimethoprim-sulfamethoxazole has long been one of the most important antibiotics in the treatment and prevention of OI and remains paramount. It has a broad spectrum of activity against Pneumocystis jiroveci, toxoplasmosis, and bacterial infections and has an important role to play in preventing life-threatening OI. New advances in treating OI are coming from a variety of quarters: in cytomegalovirus eye disease, the use of oral rather than intravenous drugs is changing the face of therapy; in cryptococcal meningitis, improved drug formulations and combination therapy is improving clearance rates and reducing drug toxicities; and in gut disease, the possibility of rapid immune restitution with ART is replacing the need for antimicrobials against cryptosporidia and microsporidia.

Drug delivery to the posterior segment of the eye

Delivery of drugs to the posterior eye is challenging, owing to anatomical and physiological constrains of the eye. There is an increasing need for managing rapidly progressing posterior eye diseases, such as age-related macular degeneration, diabetic retinopathy and retinitis pigmentosa. Drug delivery to the posterior segment of the eye is therefore compounded by the increasing number of new therapeutic entities (e.g. oligonucleotides, aptamers and antibodies) and the need for chronic therapy. Currently, the intravitreal route is widely used to deliver therapeutic entities to the retina. However, frequent administration of drugs via this route can lead to retinal detachment, endophthalmitis and increased intraocular pressure. Various controlled delivery systems, such as biodegradable and non-biodegradable implants, liposomes and nanoparticles, have been developed to overcome such adverse effects, with some success. The periocular route is a promising alternative, owing to the large surface area and the relatively high permeability of the sclera. Yet, the blood-retinal barrier and efflux transporters hamper the transport of therapeutic entities to the retina. As such, the efficient delivery of drugs to the posterior eye remains a major challenge facing the pharmaceutical scientist. In this review, we discuss the barriers of the posterior eye drug delivery and the various drug-delivery strategies used to overcome these barriers.

Intraocular implants for extended drug delivery: therapeutic applications

An overview of ocular implants with therapeutic application potentials is provided. Various types of implants can be used as slow release devices delivering locally the needed drug for an extended period of time. Thus, multiple periocular or intraocular injections of the drug can be circumvented and secondary complications minimized. The various compositions of polymers fulfilling specific delivery goals are described. Several of these implants are undergoing clinical trials while a few are already commercialized. Despite the paramount progress in design, safety and efficacy, the place of these implants in our clinical therapeutic arsenal remains limited. Miniaturization of the implants allowing for their direct injection without the need for a complicated surgery is a necessary development avenue. Particulate systems which can be engineered to target specifically certain cells or tissues are another promising alternative. For ocular diseases affecting the choroid and outer retina, transscleral or intrasscleral implants are gaining momentum.

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.

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.

Genotypic analysis of cytomegalovirus retinitis poorly responsive to intravenous ganciclovir but responsive to the ganciclovir implant

PURPOSE

To determine whether cytomegalovirus (CMV) retinitis that responded poorly to intravenous ganciclovir therapy but responded to the ganciclovir implant was caused by virus with resistance mutations in the viral UL97 and UL54 genes.

DESIGN

Retrospective chart review and laboratory-based experimental study.

METHODS

Regions of the CMV UL97 and UL54 were amplified from the vitreous and analyzed for resistant mutations by a combination of DNA sequencing and restriction digestion. Vitreous from patients with AIDS and retinal infections other than CMV retinitis served as negative controls.

RESULTS

We amplified all target regions of UL97 DNA and most target regions of UL54 DNA from eight eyes with CMV retinitis. In one eye we found a ganciclovir resistance mutation at base 1781 of the UL97 gene, predicting an alanine to valine mutation at codon 594. In a second eye we found a ganciclovir resistance mutation at base 2960 of the UL54 gene, predicting an alanine to glycine mutation at codon 987. In two additional eyes, both from patients with bilateral retinitis, we found UL54 mutations that are likely to confer resistance to ganciclovir but have not been previously described. In both of these patients the UL54 genotype differed between the two diseased eyes.

CONCLUSIONS

Failure to control CMV retinitis with intravenous ganciclovir does not necessarily imply infection with a virus having a known mutation that confers drug resistance. The ganciclovir implant can be an effective therapy for CMV retinitis caused by virus with certain UL97 and UL54 resistance mutations. Cytomegalovirus UL54 genotypes can differ between eyes in patients with bilateral retinitis.

Ultrasound biomicroscopic study of sclerotomy sites after implantation of sustained release drug devices

BACKGROUND/AIMS

To evaluate the potential of ultrasound biomicroscopy (UBM) as a tool to study the precise location and changes of sclerotomy sites of the eye with an intraocular drug delivery device.

METHODS

Eight eyes of six patients (13 sites) who received ganciclovir implants were examined by UBM. Examinations were performed 1-26 months (mean 12.8 months) postoperatively. Serial transverse and radial sections of the anterior ciliary body around the sclerotomy sites were obtained.

RESULTS

The ganciclovir implant contour was successfully viewed using an UBM with high reflectivity. Three implants were deviated anteriorly and they were very close to the ciliary body and the lens (anterior deviation), while four implants were deviated posteriorly and away from the lens (posterior deviation). The other six implants were located at the appropriate position as intended. A solitary homogeneous mass with a medium reflectivity around the suture tab was observed at 12 out of 13 sites in seven eyes. Thick membranes extending from sclerotomy sites to the ora serrata were found at two sites in two eyes.

CONCLUSION

UBM is helpful in detecting abnormal manifestations around ganciclovir implants and is a valuable tool to assess the changes of the sclerotomy sites of the sustained released intraocular devices.

Randomized dose-comparison studies of intravitreous fomivirsen for treatment of cytomegalovirus retinitis that has reactivated or is persistently active despite other therapies in patients with AIDS

PURPOSE

To compare the efficacy of two regimens of intravitreous fomivirsen for treatment of cytomegalovirus (CMV) retinitis that had reactivated or was persistently active despite other anti-CMV therapies in patients with acquired immunodeficiency syndrome (AIDS).

DESIGN

Randomized treatment intervention clinical trials.

METHODS

Two multicenter prospective randomized open-label controlled clinical trials (USA/Brazilian study; EuroCanadian study) each compared two treatment regimens of intravitreous fomivirsen (330 microg/injection), a more intense schedule (regimen A) consisting of 3 weekly injections as induction, followed by injections every 2 weeks as maintenance therapy, and a less intense schedule (regimen B), consisting of two injections at day 1 and day 15 as induction, followed by injections every 4 weeks as maintenance therapy. A total of 61 patients (67 eyes) were treated with regimen A and a total of 32 patients (39 eyes) were treated with regimen B. Time to progression was determined by masked evaluation of serial fundus photographs. The proportion of patients whose lesions became less active or inactive is described for the USA/Brazilian study as an additional measure of efficacy.

RESULTS

Results were similar for both regimens. In the USA/Brazilian study, the median time to progression was 106 days for regimen A and 267 days for regimen B (P =.2179, Wilcoxon rank sum test). In the EuroCanadian study, the median time to progression was not determinable for regimen A (25th percentile: 91 days), but was 403 days for regimen B. In the USA/Brazilian study, lesion activity decreased in 80% of patients and became inactive in 55% of patients during therapy.

CONCLUSIONS

Both regimens of intravitreous fomivirsen can be effective treatment for patients with CMV retinitis that has not been controlled by other anti-CMV drugs. The less intense regimen may be preferable in terms of convenience and safety.

Cytomegalovirus treatment options in immunocompromised patients

Cytomegalovirus (CMV) infection was recognised in congenitally infected infants in the first half of the 20th century. Following the increased use of immunosuppressive regimens for bone marrow and solid organ transplantation, various manifestations of CMV disease were recognised. Milder symptoms included fever, anorexia and malaise but severe symptoms included pneumonitis, hepatitis, gastrointestinal ulceration, choreoretinitis and encephalopathy, all with a high morbidity or mortality. With the onset of the AIDS epidemic, manifestations of CMV became evident, predominantly retinitis. Ganciclovir used intravenously has been the principal anti-CMV agent investigated. However, ganciclovir has problems with suboptimal efficacy, toxicity, poor oral bioavailability and evolution of resistant strains. Additional studies have been performed on foscarnet and cidofovir, although the use of both have been limited by their nephrotoxicity. Combination therapy with ganciclovir and foscarnet for resistant strains has been used. There are promising newer drugs like the methylenecyclopropane nucleoside analogues and benzimidazole. The most novel compound is the antisense oligonucleotide fomivirsen that has been evaluated principally in CMV retinitis. The role of immunotherapy with either immunoglobulin prophylaxis or the novel adoptive immunotherapy needs further evaluation.

Treatment of cytomegalovirus retinitis with an intraocular sustained-release ganciclovir implant

The objective of this prospective study was to evaluate the efficacy and complications of the use of an intraocular sustained-release ganciclovir implant for the treatment of active cytomegalovirus (CMV) retinitis in AIDS patients. Thirty-nine eyes of 26 patients were submitted to ocular surgery. All patients underwent complete ocular examination before and after surgery. The surgical procedure was always done under local anesthesia using the same technique. The mean time for the surgical procedure was 20 min (range, 15 to 30 min). The average follow-up period was 3.7 months. Of all patient, only 4 presented recurrence of retinitis after 8, 8, 9 and 2 months, respectively. Three of them received a successful second implant. All 39 eyes of the 26 patients presented healing of retinitis as shown by clinical improvement evaluated by indirect binocular ophthalmoscopy and retinography. Retinitis healed within a period of 4 to 6 weeks in all patients, with clinical regression signs from the third week on. Six (15.4%) eyes developed retinal detachment. None of the patients developed CMV retinitis in the contralateral eye. The intraocular implant proved to be effective in controlling the progression of retinitis for a period of up to 8 months even in patients for whom systemic therapy with either ganciclovir or foscarnet or both had failed. The intraocular sustained-release ganciclovir implant proved to be a safe new procedure for the treatment of CMV retinitis, avoiding the systemic side effects caused by the intravenous medications and improving the quality of life of the patients.

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.

Effect of potent antiretroviral therapy on recurrent cytomegalovirus retinitis treated with the ganciclovir implant

PURPOSE

To determine the effect of highly active antiretroviral therapy on cytomegalovirus (CMV) retinitis treated with ganciclovir implants.

METHODS

A retrospective cohort study was performed of 15 patients with recurrent CMV retinitis treated with the ganciclovir implant and highly active antiretroviral therapy (cases) and 38 patients with recurrent retinitis treated with ganciclovir implants before availability of improved antiretroviral therapy (controls). Progression was defined as occurrence of new lesions in the treated eye or advancement of the retinitis border by more than 750 microm.

RESULTS

Cases and controls were statistically similar in age, ethnicity, and duration of acquired immunodeficiency syndrome (AIDS). Controls had received intravenous ganciclovir for 9.5 +/- 9.5 months vs 3.5 +/- 4.6 months in cases (P = .003). The mean (+/- SE) time to progression of retinitis after implantation of the device was 26.7 +/- 2.4 months (95% confidence interval, 22.1 to 31.3) in the cases receiving highly active antiretroviral therapy vs 6.2 +/- 0.9 months (95% confidence interval, 4.5 to 7.9) in the controls (P = .001). Multivariate analysis, adjusted for preoperative variables, confirmed a significantly prolonged time to progression in patients receiving highly active antiretroviral therapy (P = .0003). The odds ratio for progression in the cases vs controls was 0.034 (95% confidence interval, 0.003 to 0.350). Cases had higher CD4+ T-lymphocyte counts (P = .004) and longer survival (P < .001) than controls.

CONCLUSION

Highly active antiretroviral therapy is associated with improved outcomes in patients with AIDS and recurrent CMV retinitis treated with the ganciclovir implant.

Treatment of recurrent cytomegalovirus retinitis with the ganciclovir implant

PURPOSE

To evaluate preoperative characteristics and outcome of the treatment of recurrent cytomegalovirus (CMV) retinitis with the ganciclovir implant.

METHODS

Records of 54 patients with acquired immunodeficiency syndrome and active, previously treated CMV retinitis who received a ganciclovir implant in one (n = 31) or both (n = 23) eyes were reviewed. Entry criteria included prior insertion and removal of an indwelling catheter or failure to respond to tolerated doses of ganciclovir and foscarnet. Preoperative factors that might correlate with outcome were analyzed, including demographic factors, duration of human immunodeficiency virus disease and CMV retinitis, indications for surgery, prior anti-CMV treatment, and extent of retinitis.

RESULTS

Forty-six patients completed 1 month of follow-up and were analyzed for outcome. Thirty-one (67.4%) had inactive retinitis at 1 month vs 15 (32.6%) with active retinitis, and they received a mean of 23.5 +/- 22.9 weeks of preoperative ganciclovir vs 58.0 +/- 52.0 weeks in patients with active retinitis (P = .003). Involvement of more than 25% of retinal area by CMV retinitis was also correlated with activity at 1 month (P < .001). Patients who received implants because of lack of venous access had a median time to progression of 8.0 +/- 3.0 months vs 2.0 +/- 1.2 months for patients who had inadequate response or intolerance to intravenous medication (P = .073). Patients with 6 months or less vs more than 6 months of preoperative ganciclovir treatment had progression at a median time of 8.0 +/- 1.7 months vs 2.0 +/- 0.3 months, respectively (P = .016).

CONCLUSION

Longer duration of preoperative ganciclovir or larger area of CMV retinitis correlates with lower success of ganciclovir implant therapy for recurrent retinitis.

Visual and anatomic outcomes associated with posterior segment complications after ganciclovir implant procedures in patients with AIDS and cytomegalovirus retinitis

PURPOSE

To determine anatomic and visual acuity outcomes of posterior segment complications after ganciclovir implant surgery.

METHODS

We reviewed the medical records of 63 patients with acquired immunodeficiency syndrome who had active cytomegalovirus retinitis in 82 eyes and who underwent 110 consecutive ganciclovir implant procedures. Preoperative and postoperative visual acuity, type of postoperative complication, treatment, and lines of visual acuity change were determined.

RESULTS

Thirty-eight eyes of 19 patients had bilateral ganciclovir implant procedures, and 25 eyes of 19 patients underwent two or more ganciclovir implant procedures. Thirteen (12%) of 110 ganciclovir implant procedures developed posterior segment complications: rhegmatogenous retinal detachment in six, vitreous hemorrhage in four, endophthalmitis in two, and cystoid macular edema with epiretinal membrane in one. Treatment included pars plana vitrectomy with silicone oil in two cases and without silicone oil in three cases, scleral buckling in one, intravitreal antibiotic injection in two, and laser photocoagulation in two. Overall, median visual acuity was 20/25 preoperatively. Median follow-up was 6 months for all eyes and 7 months for eyes with complications. Postoperative median visual acuity was 20/25 for eyes without complications vs 20/40 at 1 month, 20/60 at 3 and 6 months, and 20/100 at 12 months in eyes with complications (P < .001). More eyes with than without complications lost 2 or more lines of visual acuity (P < .001).

CONCLUSION

Postoperative complications occurred in 12% of the ganciclovir implant procedures and were associated with decreased visual acuity despite treatment.

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.

Delayed vitreous hemorrhage after placement of a ganciclovir implant for cytomegalovirus retinitis

PURPOSE

To report a massive vitreous hemorrhage in a 26-year-old woman that occurred approximately 6 weeks after she received a ganciclovir implant.

METHOD

Case report.

RESULTS

The cytomegalovirus retinitis was inactivated after uncomplicated insertion of a ganciclovir implant. Approximately 6 weeks later, the patient was examined for sudden painless visual loss caused by a dense vitreous hemorrhage.

CONCLUSION

Sustained-release ganciclovir implants may be associated with delayed vitreous hemorrhage.