Cytomegalovirus retinitis in the post-cART era

Surgery for Infectious Retinitis - When Medical Therapy Is Not Sufficient: The Moacyr E. Alvaro Pan-American Lecture 2023

BACKGROUND

Viral retinitis composes a group of infectious ocular diseases with poor prognoses. With the advent of antivirals and HAART, the treatment of these diseases has evolved and ocular outcomes have improved. However, even with prompt medical treatment, a significant number of patients will experience complications that require surgical intervention. While there has been an abundance of research examining the medical treatment of CMV retinitis and acute retinal necrosis, the research examining surgical outcomes of complications such as retinitis-associated retinal detachment is comparatively limited.

METHODS

Literature review.

RESULTS

In this review, we discuss the current literature examining treatment of CMV retinitis and acute retinal necrosis, with a focus on surgical management of complications such as retinal detachment.

CONCLUSIONS

Despite significant improvements in the medical treatment of CMV retinitis and ARN over the last three decades, vision-threatening complications such as retinal detachment are relatively common and require surgical management via PPV, laser photocoagulation, and intraocular gas or silicone oil tamponade.

Clinical features of Cytomegalovirus retinitis in patients with acquired immunodeficiency syndrome and efficacy of the current therapy

Background

Cytomegalovirus retinitis (CMVR) is the most common and sight-threatening opportunistic retinal infection in patients with acquired immunodeficiency syndrome (AIDS) and several controversies remain to be settled. We aimed to summarize the current evidence and clarify the clinical features and prognosis of CMVR in AIDS patients.

Methods

The databases PubMed, EMBASE, and Ovid from inception to April 2022 were searched to identify the relevant studies. R software version 3.6.3 was used to perform the statistical analyses. Results in proportion with 95% confidence interval (CI) were calculated using the Freeman-Tukey variant of arcsine square transformation.

Results

We finally included 236 studies comprising 20,214 patients. CMVR in AIDS was male-dominated (88%, 95%CI 86%-89%), with 57% (95%CI 55%-60%) aged <41 years and 44% (95%CI 41%-47%) being bilaterally involved. CMVR was preponderant in AIDS patients with the following characteristics: white and non-Hispanic, homosexual, HIV RNA load ≥ 400 copies/mL, and CD4+ T-cells <50 cells/μL. The positivity of CMV-DNA in blood, aqueous humor, and vitreous humor was 66% (95%CI 52%-79%), 87% (95%CI 76%-96%), and 95% (95%CI 85%-100%), respectively. The most common symptoms were blurred vision (55%, 95%CI 46%-65%), followed by asymptomatic, visual field defect, and floaters. CMVR was first diagnosed and regarded as the clue to AIDS diagnosis in 9% (95%CI 6%-13%) of CMVR patients. Approximately 85% (95%CI 76%-93%) of the CMVR patients have received cART. CMVR remission was observed in 72%-92% of patients depending on the specific category of anti-CMV therapy. The general incidence of CMVR-related RD in the entire course was 24% (95%CI 18%-29%), of which most patients received PPV with SO or gas tamponade and the rate of anatomic success was 89% (95%CI 85%-93%).

Conclusion

CMVR is a common opportunistic infection with diverse clinical features in AIDS patients, preponderant in those who are male, homosexual, or with CD4+ T-cells <50 cells/μL. Current therapies for CMVR and CMVR-related RD were shown to be effective. Early detection and routine ophthalmic screening should be promoted in AIDS patients.

Systematic review registration

PROSPERO, identifier CRD42022363105.

Clinical characteristics in the misdiagnosis of cytomegalovirus retinitis: A retrospective analysis of eight patients

Purpose

To highlight characteristics in the misdiagnosis of cytomegalovirus retinitis (CMVR).

Methods

Misdiagnosed cases related to CMVR were analyzed retrospectively at the Department of Ophthalmology, Beijing Youan Hospital, from July 2017 to October 2019. The medical records were reviewed by two independent senior ophthalmologists and the patients' clinical characteristics were analyzed.

Results

Eight patients (16 eyes) were identified with misdiagnoses related to CMVR. Six of the patients with CMVR were previously unaware of their human immunodeficiency virus (HIV) infection; one patient with CMVR concealed their history of HIV infection. The cases were initially misdiagnosed as diabetic retinopathy (1/7, 14.3%), branch retinal vein occlusion (1/7, 14.3%), ischemic optic neuropathy (1/7, 14.3%), Behçet's disease (1/7, 14.3%), iridocyclitis (2/7, 28.6%), and progressive outer retinal necrosis (1/7, 14.3%). One patient with binocular renal retinopathy and chronic renal insufficiency was misdiagnosed with CMVR. Four eyes (4/16, 25%) presented with pan-retinal involvement. Fourteen eyes (14/16, 87.5%) had optic disc or macular area involvement. At the final diagnosis, one patient was blind, and two patients had low vision. Seven AIDS patients showed an extremely low level of CD4⁺ T lymphocytes (median of 5 cells/μl; range 1-9 cells/μl).

Conclusion

CMVR may be misdiagnosed in the absence of known immune suppression. CMVR and HIV screening cannot be overlooked if a young male patient presents with yellowish-white retinal lesions. These misdiagnosed patients had severe retinitis associated with poor vision.

Cytomegalovirus retinitis and antiretroviral treatment: A fifteen year experience

Background

South Africa’s public antiretroviral treatment (ART) programme has undergone progressive changes since its introduction in 2004. The effect of this on the burden of the AIDS-defining opportunistic infection, cytomegalovirus retinitis (CMVR), in SA, has not been fully appreciated.

Objectives

To determine the effect of ART availability in the public sector of SA on the trend in the number of cases of newly diagnosed CMVR over time.

Methods

This is a retrospective study from 01 November 2002 to 31 August 2017 that took place at a tertiary hospital in the KwaZulu-Natal (KZN) province.

Results

A total of 383 participants were included in the study, with 60.1% being female and 94% of black African origin. The mean age of patients was 34.08 years (SD ± 7.24). A linear trend model suggested an overall linear decrease in the number of new cases of CMVR per year (R² of 0.67). The average number of new cases of CMVR per year prior to ART being available to all persons living with HIV (PLWH) with a CD4+ ≤ 350 cells/μL and after was 34 and 13, respectively, and the difference (61.76%) between these values was statistically significant, P = 0.001. The median CD4+ count at diagnosis of CMVR was 22 (interquartile range: 9–51.25) cells/μL. An overall 51% of patients in this study were on ART at diagnosis of CMVR. There was a higher proportion of patients on ART ≤ 6 months (63.3%), compared with those on ART > 6 months (36.7%), and the difference was statistically significant, P < 0.01.

Conclusion

ART has resulted in a decrease in the burden of CMVR on ophthalmic services for many in KZN, particularly following the introduction of ART for all PLWH with a CD4 ≤ 350 cells/μL.

Cytomegalovirus retinitis in the highly active anti-retroviral therapy era

Cytomegalovirus (CMV) retinitis is an opportunistic infection that has traditionally affected those who have HIV/AIDS or immunosuppressed individuals. CMV retinitis previously infected one-third of AIDS patients in the pre-highly active antiretroviral therapy (HAART) era, but since HAART, Western countries have seen an 80% decrease in the incidence of the disease. More recently, CMV retinitis has been reported in patients who are immunosuppressed, often due to chemotherapy or immunomodulatory medications. The diagnosis of CMV retinitis is often suspected based on clinical findings, with polymerase chain reaction for confirmation of CMV, especially in atypical cases. Highly active antiretroviral therapy and anti-CMV medications (systemic or local) remain the mainstay of treatment. However, for those who are not responsive to HAART, CMV retinitis remains a challenge, and can still lead to significant vision loss. Moreover, a regimen of anti-CMV medications can sometimes lead to viral resistance or organ toxicity. Complications such as immune recovery retinitis and rhegmatogenous retinal detachments continue to threaten the vision of patients who develop CMV retinitis. These complications can arise following initiation of treatment or if patients show disease progression. Proper vision screening for CMV retinitis in immunosuppressed patients at-risk is necessary for early detection and treatment.

Macular Structure and Microvasculature Changes in AIDS-Related Cytomegalovirus Retinitis Using Optical Coherence Tomography Angiography

Background: Cytomegalovirus retinitis (CMVR) is a crucial blind-causing disease of AIDS-related ocular opportunistic infection. The CMVR lesions produced retinal necrosis. It is not entirely clear whether CMVR eyes without macular-involved necrotic lesions may have subtle macular damage. In this study, we conducted a cross-sectional study using optical coherence tomography angiography (OCTA) to evaluate macular microvasculature and structure in eyes with AIDS-related CMVR.

Methods: Acquired immune deficiency syndrome (AIDS)-related CMVR patients (active and inactive CMVR) and healthy controls treated in the Department of Ophthalmology, Beijing Youan Hospital, Capital Medical University between August 25, 2019, and October 18, 2019, were recruited. All OCTA parameters, including the foveal avascular zone (FAZ), retinal vessel density (VD), choroidal vascularity index (CVI), retinal thickness, and choroidal thickness, were compared between groups after the signal strength was corrected.

Results: Signal strength in the 3 × 3 and 6 × 6 mm scan patterns was significantly weaker in the inactive CMVR group than in the control group (both p < 0.001). After adjusting for signal strength, heterogeneity in the central fovea and parafoveal quadrants was present with a shift toward lower macular chorioretinal vasculature, decreased full choroidal thickness, and thicker retinal thickness in the active and inactive CMVR groups. The retinal nerve fiber layer (RNFL) and inner nuclear layer (INL) were significantly thicker in the active and inactive CMVR groups than in the control group (all p < 0.05). For photoreceptor-retinal pigment epithelium (PR-RPE) thickness, no significant differences were found in any quadrant between groups. Foveal avascular zone areas were not significantly different among the three groups (p = 0.053).

Conclusions: Subtle macular structure and microvasculature damage still existed in CMVR eyes without macular-involved necrotic lesions. The results of our study are helpful for a deep understanding of the damage caused by CMVR.

Clinical Characteristics Associated with the Development of Cystoid Macular Edema in Patients with Cytomegalovirus Retinitis

We evaluated the incidence and characteristics of eyes with cytomegalovirus (CMV) retinitis according to the occurrence of cystoid macular edema (CME) and identified the risk factors of its occurrence. Patients diagnosed with CMV retinitis and examined using optical coherence tomography were classified according to the development of CME. The CME group was further divided according to the presence of active retinitis at the time of CME development. The demographics, serologic findings, ophthalmic presentations, ocular treatments, and visual prognosis were compared. CME was identified in 25 eyes (17 eyes with active retinitis and 8 eyes with inactive retinitis) out of the 67 eyes with CMV retinitis. Visual acuity was worse in the CME group than in the non-CME group. The CME group had longer CMV viremia duration, zone 1 involvement, and larger extent of CMV retinitis. While CME with concurrent active retinitis developed in eyes with direct foveal involvement of retinitis in the acute phase and required more ganciclovir injections after CME development, CME without active retinitis developed in eyes with larger extents of involvement and more intravitreal ganciclovir injections before CME development. Zone 1 involvement and longer CMV viremia duration were independently associated with the occurrence of CME. CME, which caused visual deterioration, developed in considerable patients with CMV retinitis and had different characteristics according to the presence of active retinitis.

Ocular Outcomes after Treatment of Cytomegalovirus Retinitis Using Adoptive Immunotherapy with Cytomegalovirus-Specific Cytotoxic T Lymphocytes

PURPOSE

To describe ocular outcomes in eyes with cytomegalovirus (CMV) retinitis treated with adoptive immunotherapy using systemic administration of CMV-specific cytotoxic Tlymphocytes (CMV-specific CTLs).

DESIGN

Retrospective cohort study.

PARTICIPANTS

Patients with active CMV retinitis evaluated at a tertiary care academic center.

METHODS

Treatment of CMV retinitis with standard-of-care therapy (systemic or intravitreal antivirals) or CMV-specific CTLs (with or without concurrent standard-of-care therapies).

MAIN OUTCOME MEASURES

The electronic medical record was reviewed to determine baseline characteristics, treatment course, and ocular outcomes, including best-corrected visual acuity (BCVA), treatments administered (CMV-specific CTLs, systemic antivirals, intravitreal antivirals), resolution of CMV retinitis, any occurrence of immune recovery uveitis, cystoid macular edema, retinal detachment, or a combination thereof.

RESULTS

Seven patients (3 of whom had bilateral disease [n = 10 eyes]) were treated with CMV-specific CTLs, whereas 20 patients (6 of whom had bilateral disease [n = 26 eyes]) received standard-of-care treatment. Indications for CMV-specific CTL therapy included persistent or progressive CMV retinitis (71.4% of patients); CMV UL54 or UL97 antiviral resistance mutations (42.9%); side effects or toxicity from antiviral agents (57.1%); patient intolerance to longstanding, frequent antiviral therapy for persistent retinitis (28.6%); or a combination thereof. Two patients (28.6%; 4 eyes [40%]) received CMV-specific CTL therapy without concurrent systemic or intravitreal antiviral therapy for active CMV retinitis, whereas 5 patients (71.4%; 6 eyes [60%]) continued to receive concurrent antiviral therapies. Resolution of CMV retinitis was achieved in 9 eyes (90%) treated with CMV-specific CTLs, with BCVA stabilizing (4 eyes [40%]) or improving (4 eyes [40%]) in 80% of eyes over an average follow-up of 33.4 months. Rates of immune recovery uveitis, new-onset cystoid macular edema, and retinal detachment were 0%, 10% (1 eye), and 20% (2 eyes), respectively. These outcomes compared favorably with a nonrandomized cohort of eyes treated with standard-of-care therapy alone, despite potentially worse baseline characteristics.

CONCLUSIONS

CMV-specific CTL therapy may represent a novel monotherapy or adjunctive therapy, or both, for CMV retinitis, especially in eyes that are resistant, refractory, or intolerant of standard-of-care antiviral therapies. More generally, adoptive cell transfer and adoptive immunotherapy may have a role in refractory CMV retinitis. Larger prospective, randomized trials are necessary.

Utility of Ultra-Wide-Field Imaging for Screening of AIDS-Related Cytomegalovirus Retinitis

PURPOSE

To explore the potential use of ultra-wide-field (UWF) imaging for screening of cytomegalovirus retinitis (CMVR) in AIDS patients.

METHODS

Ninety-four patients whose CD4 count was below 200 cells/μL were enrolled in a prospective study. Each patient underwent UWF imaging and indirect ophthalmoscopy. The main outcome measures were the concordance and detection rates of these 2 approaches and the sensitivity and specificity of UWF imaging.

RESULTS

Twenty-seven eyes in 18 patients were diagnosed with CMVR by the indirect ophthalmoscopy. UWF imaging missed the diagnosis in 1 eye because of a zone 3 CMVR lesion. The UWF image showed several CMVR patterns and locations: hemorrhagic necrotizing lesion, granular lesion, frosted branch angiitis, and optic neuropathy lesion. The concordance of the 2 approaches was excellent for the diagnosis of CMVR, classification of CMVR pattern, and location of CMVR. The detection rates of UWF imaging and indirect ophthalmoscopy were 14.0% (26/186; 95% CI 0.089-0.190) and 14.5% (27/186; 95% CI 0.094-0.196), respectively (p = 1.000). The sensitivity and specificity of UWF imaging were 96.3 and 100%, respectively.

CONCLUSIONS

UWF imaging is capable of documentation of different CMVR lesions and AIDS-related CMVR screening when examination by an ophthalmologist is not available.

Modified nucleic acids: replication, evolution, and next-generation therapeutics

Modified nucleic acids, also called xeno nucleic acids (XNAs), offer a variety of advantages for biotechnological applications and address some of the limitations of first-generation nucleic acid therapeutics. Indeed, several therapeutics based on modified nucleic acids have recently been approved and many more are under clinical evaluation. XNAs can provide increased biostability and furthermore are now increasingly amenable to in vitro evolution, accelerating lead discovery. Here, we review the most recent discoveries in this dynamic field with a focus on progress in the enzymatic replication and functional exploration of XNAs.

Mechanisms of AIDS-related cytomegalovirus retinitis

Human cytomegalovirus (HCMV) generates a significant clinical burden worldwide, particularly among the immune compromised. In approximately 30% of untreated HIV/AIDS patients without access or sufficient response to antiretroviral therapies, for example, HCMV causes a sight-threatening retinitis. To study the mechanisms of AIDS-related HCMV retinitis, our lab has for many years used a mouse model in which a mixture of mouse retroviruses induces murine AIDS after approximately 10 weeks, rendering otherwise resistant mice susceptible to opportunistic pathogens. This immunodeficiency combined with subretinal inoculation of murine cytomegalovirus yields a reproducible model of the human disease, facilitating the discovery of many clinically relevant virologic and immunologic mechanisms of retinal destruction which we summarize in this review.