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PubMed This is a summary of 18 peer-reviewed journal articles Updated
Ophthalmology

Standard of Care Treatment for CMV Retinitis

At a Glance

CMV retinitis is treated with an intensive induction course followed by lower-dose maintenance antivirals. Some sight-threatening lesions need eye injections, while immune recovery and regular blood and kidney tests help prevent relapse and treatment toxicity.

Treating Cytomegalovirus (CMV) retinitis is a dual-track process. Your medical team must use powerful antiviral medications to stop the virus from destroying your retina while simultaneously working to strengthen your immune system so it can eventually take over the fight [1][2].

The Two Phases of Treatment

Antiviral therapy is typically divided into two distinct stages:

  1. Induction Phase: This is the “attack” phase, usually lasting 2 to 3 weeks [3]. You will receive high doses of antiviral medication to stop the virus from multiplying and spreading [3][1].
  2. Maintenance Phase: Once the infection is “quiescent” (inactive), the dose is lowered [3]. This phase continues until your immune system is strong enough to keep the virus dormant on its own—often for at least 3 to 6 months, though some patients require prolonged or indefinite maintenance [1][4]. Never stop your therapy without explicit instructions from your care team, as missed doses promote relapse and resistance [2][5].

First-Line and Alternative Medications

Your doctor will choose a medication based on how severe your eye disease is and how well your kidneys and bone marrow are functioning. The dose and frequency are always adjusted for your kidney function.

  • Oral Valganciclovir: The preferred first-line treatment for most patients [1]. It is a pill taken twice daily for induction and once daily for maintenance [6]. It is as effective as IV treatment if your body can absorb it well [6].
  • IV Ganciclovir: Used if you cannot take pills, have severe disease, or have poor absorption [6][7].
  • Foscarnet: An IV alternative often used if the virus is resistant to ganciclovir or if your blood counts (white blood cells) are too low to safely use ganciclovir [8][9].
  • Cidofovir: A second-line IV option for resistant cases, though it carries a high risk of kidney damage [10][8].
  • Maribavir: A newer oral medication primarily used for “refractory” or resistant CMV infection after transplant [11][12]. It is a specialist-only consideration and not a routine first-line treatment for CMV retinitis, as ocular penetration evidence is limited and it has significant drug interactions with transplant immunosuppressants [11][12].

Protecting the “Posterior Pole”

If the infection is located in Zone 1—the area of the retina that includes the macula (center vision) or the optic nerve—your doctor may likely recommend intravitreal injections [1][13].

These are direct injections of ganciclovir or foscarnet into the eye. They provide an immediate, high concentration of medicine exactly where it is needed [14]. However, these injections are generally an adjunct to (an addition to) systemic therapy, not a substitute, because systemic therapy is required to treat the fellow eye and extraocular disease [13][15]. While vital for immediately sight-threatening lesions, injections carry risks including infection, pressure changes, and retinal injury [15].

The Critical Role of Immune Recovery

Antivirals suppress the virus, but they do not eradicate it. Lasting protection only comes from immune reconstitution (restoring your immune system) [16][2].

  • For HIV Patients: Prompt initiation of Antiretroviral Therapy (ART) is essential [4].
  • For Transplant Patients: Your transplant team may carefully reduce your immunosuppressant medications [2]. This is a delicate balance, as reducing these drugs can increase the risk of organ rejection or Graft-versus-Host Disease (GvHD) [2].

Monitoring for “Collateral Damage”

The drugs used to fight CMV are powerful and require close monitoring through regular, individualized laboratory tests:

Potential Side Effect Drug(s) Responsible Monitoring & Precautions
Neutropenia, Anemia, Thrombocytopenia (Low blood cell lines) Ganciclovir, Valganciclovir Regular CBC (Complete Blood Count) tests [17]. Contact your team urgently for fever, sore throat, or unusual bleeding.
Nephrotoxicity (Kidney damage) Foscarnet, Cidofovir, Ganciclovir Creatinine and eGFR blood tests; IV hydration may be needed [9][18]. Cidofovir requires probenecid and hydration [10]. Markedly reduced urine requires urgent contact.
Electrolyte Imbalance Foscarnet Monitoring of potassium, magnesium, and calcium levels [9]. Symptoms of weakness require an urgent call.

If your blood counts drop too low or your kidney function declines, your doctor may need to adjust your dose or switch your medication [17][2].

Common questions in this guide

What are the induction and maintenance phases of CMV retinitis treatment?
Induction is the first phase and usually uses a higher antiviral dose for about 2 to 3 weeks to stop the virus from multiplying. Maintenance uses a lower dose after the infection becomes inactive and often continues for at least 3 to 6 months, or longer until the immune system is strong enough. Do not stop treatment without instructions from your care team.
Is valganciclovir usually the first treatment for CMV retinitis?
Oral valganciclovir is the preferred first treatment for many patients and can work as well as intravenous treatment when the body absorbs it reliably. Intravenous ganciclovir may be used when a person cannot take pills, has severe disease, or has poor absorption. Doctors adjust the dose according to kidney function.
When are eye injections needed for CMV retinitis?
An injection of ganciclovir or foscarnet into the eye may be recommended when retinitis affects the macula or optic nerve, areas important for central vision. These injections provide a high concentration of medicine quickly but are usually added to, rather than substituted for, antiviral treatment throughout the body.
What tests are needed during CMV retinitis treatment?
Doctors commonly check complete blood counts to look for low white blood cells, anemia, or low platelets, as well as creatinine and eGFR to monitor kidney function. People receiving foscarnet also need electrolyte checks, including potassium, magnesium, and calcium. Results may lead to a dose change, a medication switch, or additional hydration.
What happens if ganciclovir cannot be used for CMV retinitis?
Foscarnet may be used when CMV is resistant to ganciclovir or blood counts are too low for safe treatment. Cidofovir is another option for resistant infection but can seriously damage the kidneys and requires precautions such as hydration and probenecid. Maribavir is mainly reserved for refractory or resistant CMV after transplant and is not a routine first treatment for retinitis.
When can maintenance treatment for CMV retinitis be stopped?
Maintenance treatment is generally continued until the retinitis remains inactive and the immune system has recovered sufficiently, with the timing depending on the cause of immune suppression and clinical tests. People with HIV may need effective antiretroviral therapy and an adequate CD4 count, while transplant patients require individualized adjustment of immunosuppressants. Only the treating team should decide when it is safe to stop.

Questions to Ask Your Doctor

Curated prompts to bring to your next appointment.

  1. 1.Is my retinitis in 'Zone 1' or near the 'posterior pole,' and do I need injections in addition to pills?
  2. 2.What is my current 'eGFR' or kidney function, and has my antiviral dose been adjusted for it?
  3. 3.How often will we check my 'absolute neutrophil count' (ANC) and kidney labs while I am on these medications?
  4. 4.If I am taking valganciclovir, should we also adjust my other transplant or HIV medications to prevent my blood counts from dropping too low?
  5. 5.If we decide to use foscarnet, what steps are you taking to protect my kidneys, and will I need IV hydration?
  6. 6.At what point can we consider stopping the 'maintenance' phase of my treatment, and what immune benchmarks (like CD4 count) do I need to reach?

Questions For You

Tap a prompt to share your answer — we'll use it plus this page's context to start a tailored conversation.

References

References (18)
  1. 1

    International consensuses and guidelines on diagnosing and managing cytomegalovirus (CMV) retinitis by the Asia-Pacific Vitreo-retina Society (APVRS), the Asia-Pacific Professors of Ophthalmology (AAPPO) and the Asia-Pacific Society of Ocular Inflammation and Infection (APSOII).

    Hwang DK, Ng DSC, Qian Z, et al.

    Asia-Pacific journal of ophthalmology (Philadelphia, Pa.) 2025; (14(5)):100248 doi:10.1016/j.apjo.2025.100248.

    PMID: 41038280
  2. 2

    Oral antiviral drugs for treatment of cytomegalovirus in transplant recipients.

    Razonable RR

    Clinical microbiology and infection : the official publication of the European Society of Clinical Microbiology and Infectious Diseases 2023; (29(9)):1144-1149 doi:10.1016/j.cmi.2023.03.020.

    PMID: 36963566
  3. 3

    Successful treatment of cytomegalovirus retinitis with oral/intravitreal antivirals in HIV-negative patients with lymphoma.

    Tasiopoulou A, Urzua CA, Lightman S

    Eye (London, England) 2023; (37(9)):1895-1903 doi:10.1038/s41433-022-02267-0.

    PMID: 36192634
  4. 4

    Long-term Outcomes of Cytomegalovirus Retinitis in the Era of Modern Antiretroviral Therapy: Results from a United States Cohort.

    Jabs DA, Ahuja A, Van Natta ML, et al.

    Ophthalmology 2015; (122(7)):1452-63.

    PMID: 25892019
  5. 5

    Maribavir for Refractory or Resistant Cytomegalovirus Infections in Hematopoietic-cell or Solid-organ Transplant Recipients: A Randomized, Dose-ranging, Double-blind, Phase 2 Study.

    Papanicolaou GA, Silveira FP, Langston AA, et al.

    Clinical infectious diseases : an official publication of the Infectious Diseases Society of America 2019; (68(8)):1255-1264 doi:10.1093/cid/ciy706.

    PMID: 30329038
  6. 6

    Effect of individualized therapy for AIDS patients with cytomegalovirus retinitis in intravitreal ganciclovir injections.

    Xie LY, Chen C, Kong WJ, et al.

    International journal of ophthalmology 2019; (12(8)):1351-1355 doi:10.18240/ijo.2019.08.19.

    PMID: 31456929
  7. 7

    Ocular involvement in highly treatment-experienced patients with HIV.

    Cobaschi M, Dorobăț CM, Dorobăț VD, et al.

    Romanian journal of ophthalmology 2024; (68(2)):152-157 doi:10.22336/rjo.2024.28.

    PMID: 39006338
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    Cytomegalovirus Treatment in Solid Organ Transplantation: An Update on Current Approaches.

    Hardinger KL, Brennan DC

    The Annals of pharmacotherapy 2024; (58(11)):1122-1133 doi:10.1177/10600280241237534.

    PMID: 38501850
  9. 9

    Real-World Effectiveness and Renal Safety of Foscarnet for CMV Reactivation After Allogeneic Hematopoietic Stem Cell Transplantation.

    Kaynar L, Ali IA, Alrais M, et al.

    Journal of clinical medicine 2026; (15(16)) doi:10.3390/jcm15166365.

    PMID: 42652768
  10. 10

    Perforation of the bowel due to cytomegalovirus infection in a man with AIDS: surgery is not always necessary!

    Yoganathan KT, Morgan AR, Yoganathan KG

    BMJ case reports 2016; (2016()).

    PMID: 27440845
  11. 11

    Maribavir for Refractory Cytomegalovirus Infections With or Without Resistance Post-Transplant: Results From a Phase 3 Randomized Clinical Trial.

    Avery RK, Alain S, Alexander BD, et al.

    Clinical infectious diseases : an official publication of the Infectious Diseases Society of America 2022; (75(4)):690-701 doi:10.1093/cid/ciab988.

    PMID: 34864943
  12. 12

    Maribavir for cytomegalovirus retinitis: A case series and review of the literature.

    Shughoury A, Emami S, Kaisari E, et al.

    AJO international 2026; (3(2)) doi:10.1016/j.ajoint.2026.100247.

    PMID: 41938663
  13. 13

    Intravitreal foscarnet is an effective adjunct after systemic therapy failure in pediatric antiviral-resistant cytomegalovirus retinitis.

    Amiri I, Shah P, Soleimani M, Zhang AY

    The Journal of international medical research 2026; (54(4)):3000605261436565 doi:10.1177/03000605261436565.

    PMID: 41986961
  14. 14

    Cytomegalovirus Retinitis in a Human Immunodeficiency Virus-negative Cohort: Long-term Management and Complications.

    Jeon S, Lee WK

    Ocular immunology and inflammation 2015; (23(5)):392-9 doi:10.3109/09273948.2014.985385.

    PMID: 25760914
  15. 15

    Comparison of two different intravitreal treatment regimens combined with systemic antiviral therapy for cytomegalovirus retinitis in patients with AIDS.

    Liang X, An H, He H, et al.

    AIDS research and therapy 2023; (20(1)):46 doi:10.1186/s12981-023-00543-x.

    PMID: 37452370
  16. 16

    Active cytomegalovirus retinitis after the start of antiretroviral therapy.

    Heiden D, Tun N, Smithuis FN, et al.

    The British journal of ophthalmology 2019; (103(2)):157-160 doi:10.1136/bjophthalmol-2018-312406.

    PMID: 30196272
  17. 17

    Treatment for First Cytomegalovirus Infection Post-Hematopoietic Cell Transplant in the AURORA Trial: A Multicenter, Double-Blind, Randomized, Phase 3 Trial Comparing Maribavir With Valganciclovir.

    Papanicolaou GA, Avery RK, Cordonnier C, et al.

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    PMID: 38036487
  18. 18

    Navigating Cytomegalovirus Retinitis in a Patient With Myelodysplastic Syndromes Transitioning to Acute Myeloid Leukemia Post Transplant: A Case Study.

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    PMID: 40051959

This page is for informational purposes only and does not constitute medical advice. Your ophthalmologist and infectious disease or transplant team must tailor CMV retinitis medicines, monitoring, and immune treatment to your situation.

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