Bilateral Retinitis Research Articles

Cytomegalovirus retinitis and FK 506

Purpose To report a case of cytomegalovirus (CMV) retinitis in a patient immunosuppressed with FK 506. Design Interventional case report. Methods Retrospective institutional study. One patient, diagnosed with bilateral CMV retinitis while on immunosuppressive treatment with FK 506, received systemic ganciclovir and intravitreal, slow-release ganciclovir implant in one eye, combined with reduction in FK 506 dose. Main outcome measures were visual acuity and regression of CMV retinitis. Results Visual acuity at presentation was 20/20 in the right eye and 20/50 in the left eye. During the 6 months of follow-up, there was no change in visual acuity in either eye. The areas of CMV retinitis demonstrated progressive regression, leaving diffuse retinal atrophy. Conclusions Cytomegalovirus retinitis can be a sight-threatening complication of immunosuppressive treatment with FK 506. Ganciclovir treatment together with a reduction in FK 506 dose was effective in preserving vision.

Delayed spread and reduction in virus titer after anterior chamber inoculation of a recombinant of HSV-1 expressing IL-16.

The timing of T-cell infiltration of the hypothalamus is crucial in the prevention of bilateral retinitis in mice inoculated with HSV-1 through the anterior chamber (AC). In H129-infected mice, T-cells are recruited to the suprachiasmatic nuclei of the hypothalamus too late to protect infected mice from development of bilateral retinitis. The purpose of these studies was to determine whether alteration of T-cell recruitment to the hypothalamus would affect the timing and pattern of virus spread after AC inoculation. A recombinant of the H129 strain of HSV-1 expressing IL-16, a cytokine with lymphocytic and monocytic chemoattractant properties, was constructed, and mice were inoculated in the AC with H129wt, H129wt and H129/IL-16, or H129wt and H129/pGal10 (a recombinant virus containing vector only). AC inoculation of BALB/c mice with H129wt and H129/IL-16 resulted in a delay of virus spread to the hypothalamus and the contralateral retina, and this delay correlated with decreased virus titers in infected tissues, compared with mice infected with H129wt or mice infected with H129wt and H129/pGal10. Although the number of infiltrating T-cells in the brains of mice infected with H129wt, H129wt and H129/IL-16, or H129wt and H129/pGal10 was similar, more Mac-1-positive cells were detected early (postinoculation day 2) in the injected eyes of mice infected with H129wt and H129/IL-16 than in mice infected with H129wt and/or H129wt and H129/pGal10. These results suggest that early recruitment of Mac-1-positive cells to the injected eye may play a role in delaying virus spread in mice infected with H129wt and the IL-16-expressing recombinant virus. IL-16 delivery vectors could be exploited to prevent or delay HSV-1 infection of the hypothalamus, allowing development of the antiviral immune response and subsequent inhibition of virus spread into the optic nerve and retina.

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

PurposeTo 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. DesignRetrospective chart review and laboratory-based experimental study. MethodsRegions 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. ResultsWe 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. ConclusionsFailure 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.

Infiltration of T-lymphocytes in the brain after anterior chamber inoculation of a neurovirulent and neuroinvasive strain of HSV-1

Following anterior chamber (AC) inoculation of BALB/c mice with the KOS strain of herpes simplex virus type 1 (HSV-1), or with H129, a neuroinvasive and neurovirulent strain of HSV-1, both strains of virus spread from the injected eye through the brain to cause retinitis. However, KOS-infected mice develop retinitis in the uninoculated eye only, whereas H129-infected mice develop bilateral retinitis. Previous studies have shown that infiltrating T-cells in the suprachiasmatic nuclei (SCN) of the hypothalamus of KOS-infected mice concomitant with or before virus protect KOS-infected mice from ipsilateral retinitis. To determine the timing of T cell infiltration and cytokine production in the brain of H129-infected mice, adjacent, frozen sections of the brain were immunostained for virus, T-cells, IL-2, TNF-α or IFN-γ. T-cells infiltrated the brains of H129-infected mice and cytokines were produced in infected tissues. However, virus spread to the optic nerve and retina of both the inoculated and uninoculated eye before T-cells and cytokines were detected in the SCN of H129-infected mice. These results suggest that infiltrating T-cells in the SCN of H129-infected mice may arrive too late to prevent the spread of virus into the optic nerves and retinas and thus prevent development of bilateral retinitis in infected mice.

Rapid spread of a neurovirulent strain of HSV-1 through the CNS of BALB/c mice following anterior chamber inoculation.

Following uniocular anterior chamber (AC) inoculation of BALB/c mice with the KOS strain of herpes simplex virus type 1 (HSV-1), virus spreads from the injected eye to the ipsilateral suprachiasmatic nucleus (SCN) in the central nervous system (CNS) to infect the optic nerve and retina of the contralateral eye, and mice develop retinitis in that eye only. In contrast, after AC inoculation of BALB/c mice with the H129 strain of HSV-1, mice develop bilateral retinitis. The pathway(s) by which H129 spreads to cause bilateral retinitis is not known. To determine the route and timing of H129 spread after AC inoculation, BALB/c mice were injected in the AC of the right eye with 5 x 10(3) PFU of H129. Brains from 30 mice were sectioned on a brain matrix and the amount of virus in the brain and eyes was determined by plaque assay. Frozen sections were prepared from the eyes, brain, and trigeminal ganglia of an additional 30 mice, and HSV-1 antigen was detected by immunohistochemistry. After AC inoculation, H129 follows a pathway similar to KOS in the CNS, but H129 appears to spread more rapidly than KOS within the CNS. Unlike KOS, H129 is able to infect brain stem nuclei and H129-infected mice developed neurological impairments in addition to bilateral retinitis. The results of these studies suggest that the ability of H129 to spread rapidly in the CNS allows early virus infection of retino-recipient nuclei proximal to the contralateral and ipsilateral optic nerves. Early infection of retino-recipient nuclei, such as the SCN may allow virus to spread into the retinas before a virus-specific immune response can be induced.

An analysis of lesion size and location in newly diagnosed cytomegalovirus retinitis

Objective To investigate the size and distribution of lesions in newly diagnosed cytomegalovirus retinitis (CMVR). Design Retrospective, observational case series. Participants Fundus photographs of 252 newly diagnosed CMVR lesions in 173 eyes of 130 patients (123 male, 7 female). Methods Thirty-five millimeter (60°) color transparencies were digitized. A montage of the retina was assembled for each involved eye and was superimposed on a specially designed map of the postequatorial retina. Cytomegalovius retinitis lesions were delineated, and the size and location of each lesion was measured. The size of newly diagnosed CMVR lesions was computed in terms of percent postequatorial retinal surface area (PERSA), and the location of lesions was plotted on a polar coordinate system. Main outcome measures Size and location of patches of newly diagnosed CMVR. Results The median lesion size was 3% PERSA. Peripheral CMVR lesions were larger than posterior ones ( P < 0.001). The mean number of lesions was 1.6 per eye. The total area of CMVR involvement ranged from 1% to 76% PERSA, with a median of 5% PERSA. There was no difference between left and right eyes in the distribution of lesion centers ( P = 0.27). The concentric distribution of lesion centers appeared to be homogeneous, except for fewer centers in the most peripheral 14° ( P < 0.001), and a greater than expected number of lesion centers in the macula (central 11.6°, P < 0.001). Eyes of patients with unilateral retinitis had 1.3 lesions per involved eye compared with eyes of patients with bilateral retinitis, which had 1.6 lesions per eye ( P = 0.003). Conclusions Most newly diagnosed CMVR lesions were small. Peripheral lesions were larger than more posterior lesions. Variations from a homogeneous distribution of lesions were noted only at the extreme peripheral and central locations and are probably explained by ascertainment bias. The macula was not spared from new CMVR lesions in this patient population.

Vitrectomy for large vitreous opacity in retinitis pigmentosa

PURPOSE: To describe a patient with bilateral retinitis pigmentosa and visually disabling vitreous opacities, who benefited from vitrectomy in both eyes. METHODS: A 37-year-old man with retinitis pigmentosa and severely constricted visual fields developed a large, dense, vitreous floater and visual obscuration in the right eye. Subsequently, diffuse vitreous opacification and visual obscuration developed in the left eye. RESULTS: Bilateral pars plana vitrectomy relieved the patient’s visual obscurations. Electron micrographs of the excised vitreous opacity from the left eye showed collagen fibrils and cellular debris. CONCLUSION: Visually significant vitreous opacities may develop as a complication of retinitis pigmentosa. The visual impact of such opacities may be magnified by its superimposition on limited visual fields. Vitrectomy may be of benefit in such cases.

Reversible bull’s-eye maculopathy associated with intravitreal fomivirsen therapy for cytomegalovirus retinitis

PURPOSE: To report two cases in which a bull’s eye maculopathy developed after intravitreal injection of fomivirsen. METHODS: Case reports. RESULTS: A 50-year-old man with acquired immunodeficiency syndrome (AIDS) and refractory cytomegalovirus retinitis developed bull’s-eye pigmentary changes in the macula of the right eye after initiating therapy with fomivirsen (Vitravene; CIBA Vision, Atlanta, Georgia) intravitreal injections. These pigmentary changes resolved upon cessation of treatment. A 36-year-old man with AIDS and refractory bilateral cytomegalovirus retinitis developed bull’s-eye pigmentary changes in both eyes during bilateral intravitreal treatment with fomivirsen. Vision was not affected. These changes resolved after treatment with fomivirsen was stopped. CONCLUSION: Fomivirsen, a new medication for the treatment of refractory cytomegalovirus retinitis, may cause a bull’s-eye maculopathy in some patients. The bull’s-eye maculopathy is reversible and does not appear to affect vision.

Neuronal pathways for the propagation of herpes simplex virus type 1 from one retina to the other in a murine model.

Herpetic retinitis in humans is characterized by a high frequency of bilateral localization. In order to determine the possible mechanisms leading to bilateral retinitis, we studied the pathways by which herpes simplex virus type 1 (HSV-1) is propagated from one retina to the other after intravitreal injection in mice. HSV-1 strain SC16 (90 p.f.u.) was injected into the vitreous body of the left eye of BALB/c mice. Animals were sacrificed 1, 2, 3, 4 and 5 days post-inoculation (p.i.). Histological sections were studied by immunochemical staining. Primary retinitis in the inoculated eye (beginning 1 day p.i.) was followed by contralateral retinitis (in the uninoculated eye) starting at 3 days p.i. Infected neurons of central visual pathway nuclei (lateral geniculate nuclei, suprachiasmatic nuclei and pretectal areas) were detected at 4 days p.i. Iris and ciliary body infection was minimal early on, but became extensive thereafter and was accompanied by the infection of connected sympathetic and parasympathetic pathways. The pattern of virus propagation over time suggests that the onset of contralateral retinitis was mediated by local (non-synaptic) transfer in the optic chiasm from infected to uninfected axons of the optic nerves. Later, retinopetal transneuronal propagation of the virus from visual pathways may have contributed to increase the severity of contralateral retinitis.

Association of antiretinal antibodies and cystoid macular edema in patients with retinitis pigmentosa

PURPOSE: To report the association of antiretinal antibodies in patients with bilateral cystoid macular edema and retinitis pigmentosa. METHODS: In a prospective study, 30 consecutive patients with bilateral cystoid macular edema and retinitis pigmentosa were tested for antiretinal antibodies. As control subjects, 30 consecutive patients with retinitis pigmentosa who did not have cystoid macular edema and 50 normal subjects without retinitis pigmentosa or cystoid macular edema were tested for antiretinal antibodies. Laboratory personnel performing the antiretinal antibody testing were masked regarding the diagnosis of each patient. RESULTS: Twenty-seven (90%) of 30 patients with retinitis pigmentosa with cystoid macular edema had antiretinal protein antibody activity, compared with three (6%) of 50 normal controls ( P < .001) and only four (13%) of 30 control patients with retinitis pigmentosa ( P < .001). CONCLUSIONS: We found a significant association between cystoid macular edema and the presence of circulating antiretinal antibodies in patients who presented with retinitis pigmentosa and cystoid macular edema. This study suggests that patients with retinitis pigmentosa with cystoid macular edema may have an autoimmune process that is contributing to the formation of cystoid macular edema in retinitis pigmentosa, but to date, there is no direct evidence that the cystoid macular edema is caused by the antiretinal antibodies.

Identification of BK virus in a patient with acquired immune deficiency syndrome and bilateral atypical retinitis

Objective To report the clinical and histopathologic characteristics of BK virus (BKV) retinitis. Design Case report. Testing The clinical features of bilateral retinitis in a 29-year-old homosexual white male with the acquired immune deficiency syndrome (AIDS) included focal, mottled fundus pigmentation, and haloes, as documented by fundus photography. After death of the patient, the left eye was studied by light microscopic and immunohistochemical examination. The nested polymerase chain reaction (PCR) was used to detect viral deoxyribonucleic acid (DNA) in the right eye and other nonocular tissues. The specificity was then confirmed by restriction enzyme analysis. Results The retina of the left eye showed focal necrosis and contained cells with intranuclear staining for the BKV VP1 protein. In the right eye, BKV DNA was detected in the retina and other tissues by nested PCR. Autopsy showed that BKV infection was also present in the brain, kidneys, and peripheral blood mononuclear cells. Conclusions A number of pathogens may cause retinitis in patients with AIDS. The authors have shown that BKV should be included among those pathogens and that some clinical features may suggest the presence of BKV retinitis.

Fuchs' heterochromic uveitis associated with retinitis pigmentosa

We report a case of bilateral retinitis pigmentosa simplex (RP) with a combination of unilateral Fuchs' heterochromic uveitis (FHU). Both of these entities are quite rare syndromes and coexistence of these entities in one patient is rarer than can be expected. Even though this rare coexistence came together in one patient, we found no hereditary factors to presume that both traits segregate independently.

Resolution of Recalcitrant Molluscum Contagiosum Virus Lesions in Human Immunodeficiency Virus-Infected Patients Treated With Cidofovir

Molluscum contagiosum virus (MCV) causes cutaneous skin growths that mainly affect children, sexually active adults, and immunocompromised individuals. Lesions of MCV in patients infected with human immunodeficiency virus can be large and numerous, and response to available treatments is often unsatisfactory. We describe 3 men infected with human immunodeficiency virus who presented with extensive MCV lesions that were not responsive to various treatments. Patient 1 demonstrated dramatic clearing of his MCV lesions when intravenous cidofovir therapy was started for his treatment-resistant bilateral CMV retinitis and because of cidofovir's possible activity against MCV. In case 2, cidofovir was compounded as a 3% cream in a combination vehicle (Dermovan) for extensive facial involvement, and complete resolution of MCV was seen after 1 month of therapy. In case 3, intravenous cidofovir therapy was started both for CMV retinitis and in an attempt to clear 90% facial MCV involvement; after 1 month of treatment, all clinical evidence of MCV had resolved. All 3 patients remain clear of recurrence. Cidofovir, a nucleotide analog of deoxycytidine monophosphate, appears to have contributed to clearing of advanced MCV lesions in these 3 patients, thus providing suggestive evidence of clinical activity against MCV. Controlled trials of cidofovir therapy for MCV in persons infected with human immunodeficiency virus are warranted.

Treatment of Bilateral Cytomegalovirus Retinitis With Sustained-release Ganciclovir Implants in a Child

To report treatment of bilateral cytomegalovirus (CMV) retinitis in an 11-year-old girl with acquired immunodeficiency syndrome (AIDS). Case report describing the use of intravitreal ganciclovir sustained-release devices to treat CMV retinitis, involving zones 1 through 3, which progressed despite single and combination intravenous therapy with ganciclovir and foscarnet. Stabilization with no active CMV retinitis was achieved after bilateral implantation of intravitreal sustained-release ganciclovir devices. There was no reactivation of the retinitis during the 5 months of follow-up. Sustained-release ganciclovir implants can be used to achieve local control of CMV retinitis in the pediatric patient.

Rhegmatogenous Retinal Detachments in HIV-Positive Patients With Ocular Syphilis

The purpose of this study is to report retinal manifestations of lues in human immunodeficiency virus (HIV)-positive patients and to suggest a method for treatment of rhegmatogenous retinal detachments in these patients. Two HIV-positive patients with bilateral retinitis were examined and treated at the authors' institution for a period of 14 months. Ocular syphilis was diagnosed clinically, confirmed by cerebrospinal fluid serologic testing, and treated with intravenous penicillin. Both patients experienced bilateral rhegmatogenous retinal detachments complicated by proliferative vitreoretinopathy after resolution of the active retinitis. All four eyes underwent surgical repair with trans pars plana vitrectomy, epiretinal membrane delamination, gas-fluid exchange, endolaser, scleral buckle, and silicone oil instillation. The recognition of ocular syphilis as a cause of retinal detachment in HIV-positive patients is important. Prompt intervention with the appropriate medical and surgical treatments may result in the preservation of vision in these patients.

Detection of human herpes virus 6 in AIDS-associated retinitis by means of in situ hybridization, polymerase chain reaction and immunohistochemistry.

The ubiquitous nature of HHV-6 and its genomic relationship with cytomegalovirus led us to evaluate an etiological link between HHV-6 and AIDS-associated retinitis in a prospective study. HHV-6 infection was studied in patients with AIDS-associated retinitis and in two control populations. Eye pairs were obtained at necropsy from nine patients with AIDS-associated retinitis, four human immunodeficiency virus (HIV)-sero-positive patients with normal fundus examination and three HIV-seronegative patients. HHV-6 infection was detected by polymerase chain reaction (PCR), in situ hybridization and immunohistochemistry. Human cytomegalovirus (CMV) and HIV-1 infections were detected in parallel by the same methods. HHV-6 infection was detected in three cases of AIDS-associated retinitis. In two of these patients, HHV-6 infection was detected both by immunohistochemistry and PCR while in the third case it was detected by in situ hybridization and PCR. In the three patients, fundus examination showed bilateral retinitis in two of them and unilateral retinitis in one of them. HHV-6 infection was not detected in the retina of the two control groups. CMV was also detected in the three cases positive for HHV-6 by all three methods. HIV DNA was detected by PCR in two of three cases and was confirmed in one of these cases by in situ hybridization. These results confirm that HHV-6 infects the retina but suggests that HHV-6 does not have an exclusive causative role in AIDS-associated retinitis, since CMV coinfection of the retina was detected in all three of the patients positive for HHV-6.

Acquired Immunodeficiency Syndrome—Associated Herpes Simplex Virus Retinitis

To describe 2 patients with acquired immunodeficiency syndrome who experienced a rapidly progressive, bilateral retinitis due to herpes simplex virus (HSV) (1 case due to HSV type 1 [HSV-1] and 1 case due to HSV type 2 [HSV-2] and to present a novel diagnostic polymerase chain reaction (PCR)-based assay. The presentation, clinical course, and diagnostic PCR-based assay used to make the diagnosis of HSV retinitis in 2 patients with acquired immunodeficiency syndrome are described. Both patients experienced a rapidly progressive, bilateral retinal necrosis associated with intraretinal hemorrhages and a diffuse vasculitis. The PCR-based assays demonstrated HSV DNA in the vitreous specimens from the 2 patients. Restriction analysis on the amplified DNA showed HSV-1 in 1 patient and HSV-2 in the second patient. The diagnosis was supported in both patients by the occurrence of a herpes simplex-like encephalitis, and in 1 patient by a positive vitreous culture. The HSV-1-associated vasculitis affected primarily the retinal arterioles, with marked capillary dropout and occlusion of larger arcade vessels. In contrast, the HSV-2-associated vasculitis affected the retinal veins more than the arterioles, and was associated with an exudative retinal detachment. To our knowledge, these are the first 2 patients with acquired immunodeficiency syndrome in whom HSV has been implicated as the sole cause of a rapidly progressing, necrotizing retinitis. Combined PCR and restriction analysis of vitreous samples from such patients is a useful and highly specific means of diagnosing HSV-1 and HSV-2 retinitis.

PROGRESSIVE OUTER RETINAL NECROSIS SECONDARY TO VARICELLA ZOSTER VIRUS IN ACQUIRED IMMUNE DEFICIENCY SYNDROME

A syndrome consisting of rapidly progressive outer retinitis in patients with suppressed immune systems has been described. The etiologic agent appears to be a member of the herpes virus family. A 41-year-old man with acquired immune deficiency syndrome (AIDS) developed bilateral outer retinitis and choroiditis, which progressed despite antiviral treatment. A transscleral eye wall biopsy specimen and whole globe were submitted for microbiologic and histologic study. Polymerase chain reaction of a transscleral eye wall biopsy specimen and of the enucleated specimen determined the etiologic agent to be varicella zoster virus (VZV). Histologic studies demonstrated intranuclear inclusions consistent with viral particles in choroidal cells. Our study revealed intranuclear inclusions in choroidal cells, a previously undocumented finding in progressive outer retinal necrosis. Polymerase chain reaction was very useful in identifying the causative agent.

Protective effects of interferon-gamma in intraocular herpes simplex type 1 infection do not depend on major histocompatibility complex class I or class II expression.

Intraocular infection with herpes simplex virus type I strain F (HSV-1) induces bilateral retinitis, the expression of both MHC class I and II molecules and activation of CD4 and CD8 cells. To investigate the role of MHC upregulation in IFN-gamma mediated antiviral effects in intraocular infection with HSV-1, we infected MHC deficient mice and mice with an additional ectopic site of IFN-gamma production in their retina (rho gamma) intravitreally with HSV-1 into one eye. Protective effects of IFN-gamma in intraocular HSV-1 infection were notable as sparing of the contralateral non-inoculated eye from retinitis, and were not dependent on MHC class I and class II expression, thus limiting the importance of MHC expression for the outcome of viral infection in vivo.

Ectopic expression of gamma interferon in the eye protects transgenic mice from intraocular herpes simplex virus type 1 infections.

Transgenic (rho gamma) mice provide a model for studying the influence of gamma interferon (IFN-gamma) produced in the eye on ocular and cerebral viral infection. To establish this model, we injected BALB/c- and C57BL/6-derived transgenic and nontransgenic mice of different ages intravitreally with herpes simplex virus type 1 (HSV-1) strain F. Eye and brain tissues of these mice were assessed for pathological and immunocytochemical changes. HSV-1 infection induced severe retinitis of the injected eyes and infection of the brain in all mice. In transgenic mice inoculated with HSV-1, the left, nontreated eyes were protected from retinitis, whereas nontransgenic mice developed bilateral retinitis. Additional intravitreal injection of IFN-gamma with the virus protected the noninoculated eyes of nontransgenic mice. Three-week-old nontransgenic mice died from HSV-1 infection, whereas transgenic mice of the same age and nontransgenic mice intravitreally treated with IFN-gamma survived. Ocular IFN-gamma production increased the extent of inflammation in transgenic mice but did not have a significant influence on the growth of HSV-1 until day 3 after inoculation and did not influence the neuroinvasion of this virus. Thus, the effects of IFN-gamma were not caused by an early block of viral replication. Possible mechanisms of IFN-gamma action include activation of the immune response, alteration of the properties of the virus, and direct protection of neurons.