Therapy for Acute Retinal Necrosis

Examining the etiological factors resulting in retinal detachment following prophylactic vitrectomy in the context of acute retinal necrosis syndrome

OBJECTIVE

The aim of this study is to elucidate the factors contributing to the occurrence of retinal detachment (RD) following prophylactic vitrectomy in cases of acute retinal necrosis (ARN) syndrome.

METHODS

A retrospective examination was undertaken, encompassing the medical records of patients diagnosed with ARN who underwent prophylactic vitreous intervention at the Ophthalmology Department of Wuhan University Renmin Hospital East Campus between October 2019 and September 2023. Subsequently, patients who manifested RD in the postoperative period were identified, and a comprehensive analysis was conducted to ascertain the factors underlying the occurrence of RD post-surgery.

RESULTS

This study comprised 14 cases (involving 14 eyes) of patients diagnosed with ARN who underwent prophylactic vitreous intervention. The findings revealed that 4 patients experienced postoperative RD, resulting in an incidence rate of 28.57%. Notably, among these cases, 3 cases of RD manifested in the presence of silicone oil, while 1 case occurred subsequent to the removal of silicone oil. All 4 cases of RD exhibited varied degrees of proliferative vitreoretinopathy. Following the occurrence of RD, all patients underwent a secondary vitreous intervention coupled with silicone oil tamponade, leading to successful reattachment of the retina. However, despite these interventions, there was no significant enhancement observed in postoperative visual outcomes when compared to preoperative levels.

CONCLUSION

RD following prophylactic vitrectomy in cases of ARN is not an infrequent occurrence and is primarily linked to the postoperative onset of proliferative vitreoretinopathy.

Herpes simplex virus, varicella-zoster virus and cytomegalovirus keratitis: Facts for the clinician

Keratitis due to Herpes simplex virus (HSK), Varicella-Zoster virus (VZK) and Cytomegalovirus remains a frequent source of concern for many ophthalmologists. They are a frequent cause of emergency consultations at eye care centers and carry the risk of permanent loss of visual acuity or visual quality and/or chronic neurotrophic keratitis, resulting in a significant decrease in the quality of life. HSK and VZK can affect the corneal epithelium, stroma, or endothelium or a combination of layers. In contrast, most cases of CMV keratitis present as isolated endothelitis (CMVE), a clinical entity that has been described within the last 2 decades. These three types of viral keratitis are characterized by a high frequency of recurrences and each new episode increases the risk of sequelae. Hence, ophthalmologists must adapt the treatment to the clinical presentation of each recurrent episode in order to mitigate the immediate consequences of viral replication and the immune response on corneal transparency. In patients with frequent recurrences, preventive long-term antiviral treatment is strongly recommended. However, in some rare cases, continuous exposure to antivirals may promote the emergence of resistant viral strains, which can be difficult to manage. In the future, the introduction of new antiviral drugs, with differing modes of action compared to current medical therapy, could be an alternative until a truly effective preventive solution, such as a vaccine, is available.

Socioeconomic disadvantage and impact on visual outcomes in patients with viral retinitis and retinal detachment

While socioeconomic disparities impact clinical care and patient outcomes, their impact on the anatomic and visual outcomes of retinal detachment in patients with viral retinitis is unstudied. This case series included 18 eyes in 18 patients from a single academic institution between January 1, 2008 and December 31, 2018. Patient characteristics including age, sex, race, ethnicity, insurance, immunosuppression, viral retinitis, retinal detachment, retinal detachment repair, visual and anatomic outcomes, missed appointments, and Area Deprivation Index [ADI] were collected. The low-ADI group, indicating less socioeconomic disadvantage, was comprised of twelve patients with national ADIs less than 38, and the high-ADI group of six patients with national ADIs greater than 38. High-ADI patients tended to be younger (average age 38.0 versus 51.3; P = 0.06), of female sex (P = 0.03), and had more missed appointments (median 11.0 vs 0; P = 0.002). A similar number of patients in both the high-ADI and low-ADI groups underwent pars plana vitrectomy alone or pars plana vitrectomy with scleral buckle. Visual acuity was similar in the high-ADI group than in the low-ADI group at baseline, but worse at the final follow-up visit (P = 0.004). Post-operative and final visit ocular hypotony were more common in the high-ADI group (P = 0.02). In our series, socioeconomic disadvantage negatively affects the visual outcomes in patients with viral retinitis associated-retinal detachments. These factors should be considered by ophthalmologists when treating these patients.

Acute Retinal Necrosis: Clinical Features, Diagnostic Pitfalls, Treatment, and Outcome of an Insidious Disease in Children. Case Report and Review of the Literature

OBJECTIVE

This study aims to explore clinical features, diagnostic work-up, treatment, and outcomes of pediatric patients with acute retinal necrosis (ARN), and to propose a standardized management of this condition in childhood.

METHODS

Clinical manifestations, diagnostic work-up, and treatment of three pediatric cases with ARN were analyzed. Furthermore, a review of the literature was performed from January 1990 to November 2021, focused on 1) clinical presentation; 2) differential diagnosis, including both infectious and non-infectious conditions; 3) key role of diagnostic techniques; and 4) currently available treatments.

RESULTS

Data from 72 children with ARN (69 from literature and 3 from our center) were analyzed. The most frequent presenting symptoms were red eye resistant to topical treatment (57%) and altered vision (58%), 25 patients had bilateral involvement. In 30% a known history of herpetic infection was reported. PCR testing on anterior chamber and/or vitreous sampling was performed in 46 cases (64%) and was diagnostic in 88% of them, with herpes simplex virus (HSV) 2 being the most frequently identified pathogen (57%). All patients underwent systemic antiviral therapy (16% only oral); adjunctive intravitreal injections were performed in 21% of them.

CONCLUSIONS

ARN is a rare but severe ocular infection presenting as a panuveitis with occlusive retinal vasculitis and peripheral retinal necrosis. Varicella-zoster virus and HSV 1-2 are most frequently implicated. Due to a high incidence of rhegmatogenous retinal detachment and optic atrophy, ARN has a poor prognosis with a potentially severe impact on visual function. Although a prompt recognition is crucial to prevent complications, ARN diagnosis in children is still challenging.

ACUTE RETINAL NECROSIS: Difference in Outcome by Viral Type and Options for Antiviral Therapy

PURPOSE

To investigate differences in outcomes of acute retinal necrosis with confirmed viral polymerase chain reaction between viral types and highlight different treatment options.

METHODS

The study evaluated 22 eyes in 18 patients of polymerase chain reaction-positive acute retinal necrosis at the University of Pittsburgh Medical Center from 2007 to 2018. Outcome measures included final visual acuity, treatment paradigms, and retinal detachment rate.

RESULTS

Eight eyes were polymerase chain reaction-positive for varicella zoster virus, two eyes for herpes simplex virus Type 1 (HSV-1), and 12 eyes for herpes simplex virus Type 2 (HSV-2). Final Snellen best-corrected visual acuity averaged 20/51 for varicella zoster virus, 20/25 for HSV-1, and 20/814 for HSV-2. Retinal detachment occurred in 2 (25%) of varicella zoster virus eyes and 8 (75%) of HSV-2 eyes. One eye with HSV-1 and three eyes with HSV-2 received cidofovir for treatment of refractory retinitis.

CONCLUSION

Acute retinal necrosis secondary to HSV-2 tended to have persistent active retinitis with a higher rate of retinal detachment despite similar treatment protocols, suggesting that in some cases combination intravenous acyclovir and adjuvant intravitreal foscarnet injections are not sufficient. Despite the risk of renal toxicity, intravenous cidofovir may be a consideration in select patients.

RETINAL DETACHMENT AFTER ACUTE RETINAL NECROSIS AND THE EFFICACIES OF DIFFERENT INTERVENTIONS: A Systematic Review and Metaanalysis

PURPOSE

To estimate the rate of retinal detachment (RD) after acute retinal necrosis (ARN) and evaluate the efficacies of different interventions.

METHODS

The databases Medline and EMBASE from inception to March 2020 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 were calculated using generalized linear mixed models.

RESULTS

Sixty-seven studies involving 1,811 patients were finally included. The pooling results suggested the general RD rate of ARN was 47%. The RD rate increased with the extent of retinitis and was slightly lower when involved Zone III. The RD rate was 37% for herpes simplex virus ARN and 46% for varicella-zoster virus ARN; 52% for immunocompetent patients and 39% for immunocompromised patients. Retinal detachment presented in 2% of eyes at the first visit. Systemic antiviral therapy could lower the RD rate significantly from 67% to 43%, and prophylactic vitrectomy could lower the RD rate significantly from 45% to 22%. Systemic antiviral therapy plus vitrectomy achieved the lowest RD rate to 18%. Although the efficacy of prophylactic laser or intravitreal antiviral therapy was still limited. Prophylactic vitrectomy might significantly increase the incidence of proliferative vitreoretinopathy from 7% to 32%.

CONCLUSION

About half of the eyes might develop RD during the entire course of ARN. Systemic antiviral therapy and prophylactic vitrectomy are effective interventions to prevent RD, whereas the roles of prophylactic laser or adjunctive intravitreal antiviral therapy are still unclear. Varicella-zoster virus ARN and cases with extensive retinitis might need intensified interventions.

Acute retinal necrosis: Clinical manifestation and long-term visual outcomes in a series of polymerase chain reaction-positive patients

PURPOSE

To report the clinical spectrum, viral etiologies, therapeutic interventions, timing of rhegmatogenous retinal detachments (RRD), and visual outcomes in acute retinal necrosis (ARN) syndrome in a series of polymerase chain reaction (PCR)-positive eyes.

METHODS

From January 2010 to January 2017, consecutive patients with the clinical diagnosis of ARN and a positive aqueous viral PCR were included in this observational, retrospective study.

RESULTS

Nineteen eyes found to have a clinical diagnosis of ARN, of which 18 (94.7%) had a positive viral PCR. ARN was unilateral, except in one patient. None of the fellow eyes manifested ARN during follow-up. Varicella-zoster virus (VZV) was detected in 78.0% of ARN eyes. 61.1% of eyes experienced RRD. The median time for the occurrence of RRD was 12 weeks (range: 6-25 weeks) after disease onset. No correlation was found between the etiologic viral agent (VZV vs non-VZV; p = 1.000), extent of retinitis (1-2 quadrant vs 3-4 quadrants; p = 0.326), administration of intravitreal ganciclovir (injected vs not injected; p = 0.332), application of prophylactic laser retinopexy (applied vs not applied; p = 0.326), and subsequent occurrence of RRD.At a 2-year follow-up, visual impairment (VA ⩽ 20/200) and severe visual loss (VA ⩽ light perception) were significantly higher in those complicated by RRD compared to non-RRD eyes (81.8% vs 28.6%; p = 0.047, and 45.4% vs 0.0%; p = 0.004, respectively).

CONCLUSION

Aqueous PCR results are highly consistent with the clinical diagnosis of ARN. Regardless of the method of management, the rate of RRD is high and is associated with a poor visual outcome.

Varicella-zoster virus as a causative agent of acute retinal necrosis in younger patients

Background:

Herpes virus is considered to be the pathogen of acute retinal necrosis (ARN) infection. Previous studies have found that patients with ARN caused by the varicella-zoster virus (VZV) are often older, and patients with herpes simplex virus (HSV) induced ARN are considerably younger. However, in our clinical work, we find that VZV is also a pathogen in younger ARN patients. We, therefore, aimed to analyze the common etiology of younger ARN patients.

Methods:

A retrospective analysis was made of 20 eyes (18 patients) diagnosed as having ARN in the Department of Ophthalmology of Peking Union Medical College Hospital from 2014 to 2016. All patients were reviewed for demographic data, clinical course, clinical manifestations, time from onset to initial physician visit, duration of follow-up, visual acuity at both presentation and final visit, and treatment strategies. A paired t test was used to compare visual acuity between the presenting vision and those of final follow-up. Vitreous or aqueous specimens from 18 eyes of 18 patients were analyzed with multiplex polymerase chain reaction (mPCR)/quantitative PCR (qPCR) and xTAG-liquid chip technology (xTAG-LCT) to determine the causative virus of ARN.

Results:

Final best visual acuity (BCVA) improved significantly from 1.36 ± 0.95 (median 20/400) to 0.95 ± 0.82 (median 20/100) (t = 2.714, P = 0.015) after systemic and intravitreal antiviral treatment combined with or without pars plana vitrectomy. PCR and xTAG-LCT results showed four of the five samples in the younger group (32.2 ± 5.2 years) and 12 of the 13 samples in the senior group (53.6 ± 4.9 years) were positive for VZV, and two of the five samples in the younger group were positive for HSV-1.

Conclusions:

This study demonstrates that VZV is also a common causative virus for ARN in younger patients. Considering this finding, a systemic antiviral treatment protocol should be immediately changed to intravenous ganciclovir when the patient does not respond to acyclovir before determining the causative virus, especially in younger patients.

Acute Retinal Necrosis Multicenter Case Series: Prognostic Indicators and Treatment Outcomes

Purpose:

The purpose of this article is to report the prognostic associations of acute retinal necrosis (ARN), determine the diagnostic utility of aqueous vs vitreous polymerase chain reaction (PCR), and describe outcomes of antiviral, corticosteroid, antithrombotic, and laser retinopexy treatment.

Methods:

A retrospective, nonrandomized case series was conducted. Primary outcomes included final visual acuity (VA), severe VA loss (≥1.00 log of the minimum angle of resolution [logMAR] [Snellen equivalent, <20/200]), and retinal detachment (RD).

Results:

Fifty eyes of 46 patients were diagnosed with ARN. Varicella-zoster and herpes simplex viruses were the viral etiology in 29 and 16 eyes, respectively. Five were diagnosed on clinical criteria. Intravenous acyclovir was administered in 90% of eyes. Neither induction therapy for ≥13 days ( P = .692) nor intravitreal medication ( P = .203) decreased the incidence of severe vision loss. Maintenance antiviral medication was administered in 96% of eyes (50% received >13 weeks). At final follow-up, 40% of eyes had severe vision loss (range, –0.08 to +3.0 logMAR [Snellen, 20/17-no perception of light]). Forty-six percent developed RD. Relative afferent pupillary defect (RAPD), zone and extent of retinitis, and RD were prognostic of final VA. Antithrombotic therapy was administered in 25/50 eyes and was associated with lower incidence of severe VA loss ( P = .027) and better final VA ( P = .040). Laser retinopexy was performed in 40% of eyes with no significant effect on RD incidence ( P = .901) or severe VA loss ( P = .451).

Conclusions:

ARN has a high incidence of RD and poor visual outcomes. Aqueous humor PCR is the first-line diagnostic investigation. Prognostic indicators include RD, RAPD, zone, and extent of retinitis. Induction antiviral medication is appropriate for at least 12 days. Antithrombotic medication is associated with improved outcomes. Laser retinopexy does not reduce the incidence of RD.

Emerging concepts in the management of acute retinal necrosis

Acute retinal necrosis (ARN), also known as Kirisawa-type uveitis, is an uncommon condition caused by infection of the retina by one of the herpes family of viruses, most typically varicella zoster virus or herpes simplex virus and less commonly cytomegalovirus. Clinical diagnosis can be challenging and is often aided by PCR-based analysis of ocular fluids. Treatment typically involves extended use of one or more antiviral agents. Long term retinal detachment risk is high. We review the literature on ARN and present an approach to the diagnosis and management of this serious condition.

Recent Updates on Treatment of Ocular Microbial Infections by Stem Cell Therapy: A Review

Ocular microbial infection has emerged as a major public health crisis during the past two decades. A variety of causative agents can cause ocular microbial infections; which are characterized by persistent and destructive inflammation of the ocular tissue; progressive visual disturbance; and may result in loss of visual function in patients if early and effective treatments are not received. The conventional therapeutic approaches to treat vision impairment and blindness resulting from microbial infections involve antimicrobial therapy to eliminate the offending pathogens or in severe cases; by surgical methods and retinal prosthesis replacing of the infected area. In cases where there is concurrent inflammation, once infection is controlled, anti-inflammatory agents are indicated to reduce ocular damage from inflammation which ensues. Despite advances in medical research; progress in the control of ocular microbial infections remains slow. The varying level of ocular tissue recovery in individuals and the incomplete visual functional restoration indicate the chief limitations of current strategies. The development of a more extensive therapy is needed to help in healing to regain vision in patients. Stem cells are multipotent stromal cells that can give rise to a vast variety of cell types following proper differentiation protocol. Stem cell therapy shows promise in reducing inflammation and repairing tissue damage on the eye caused by microbial infections by its ability to modulate immune response and promote tissue regeneration. This article reviews a selected list of common infectious agents affecting the eye; which include fungi; viruses; parasites and bacteria with the aim of discussing the current antimicrobial treatments and the associated therapeutic challenges. We also provide recent updates of the advances in stem cells studies on sepsis therapy as a suggestion of optimum treatment regime for ocular microbial infections.

Intraocular Detection of Herpes viruses by xTAG Liquid Chip Technology in Patients with Acute Retinal Necrosis

PURPOSE

To evaluate the performance of the xTAG liquid chip technology (xTAG-LCT) for etiological diagnosis of acute retinal necrosis (ARN).

METHODS

Fifteen vitreous and 3 aqueous samples from 18 ARN patients were analyzed by xTAG-LCT and multiplex PCR (mPCR)/quantitative PCR (qPCR).

RESULTS

xTAG-LCT revealed positive results in 17 of the 18 samples: 10 for Varicella Zoster Virus (VZV) alone; 5 for VZV and Epstein-Barr virus (EBV); 1 for herpes simplex viruses type 1 (HSV-1) and EBV; 1 for VZV, HSV-1 and EBV. While mPCR revealed the same results as xTAG-LCT for VZV and HSV-1 in all samples, only 2 of the 7 samples positive for EBV on xTAG-LCT were confirmed by qPCR. None of the 28 control vitreous samples from 8 non-ARN patients and 10 pair of cadaveric eyes was positive for any of the tested viruses.

CONCLUSIONS

xTAG-LCT could be a useful alternative for etiological diagnosis of ARN.

Acute Retinal Necrosis: Presenting Characteristics and Clinical Outcomes in a Cohort of Polymerase Chain Reaction-Positive Patients

PURPOSE

To identify determinants of adverse outcomes in acute retinal necrosis (ARN), presenting characteristics and incidence rates of vision loss and ocular complications in a cohort of polymerase chain reaction (PCR)-positive eyes were analyzed.

DESIGN

Retrospective observational cohort study.

METHODS

Forty-one eyes of 36 patients with clinically diagnosed ARN, PCR-positive for herpes simplex virus or varicella zoster virus and evaluated between January 2002 and June 2013, were included. Main outcome measures included incidence rates of vision loss and retinal detachment (RD).

RESULTS

Presenting visual acuity was generally poor (20/50 to >20/200 in 27%; 20/200 or worse in 56%). The incidence rate of ≤20/200 was 0.66/eye-year (EY), (95% confidence interval [CI], 0.32/EY to 1.22/EY); the rate of light perception or no light perception vision was 0.07/EY (95% CI, 0.02/EY to 0.16/EY). During follow-up, 59% of eyes developed at least 1 RD (rate = 0.40/EY, 95% CI, 0.19/EY to 0.58/EY). Eyes with retinitis involving ≥25% of the retina at presentation detached at nearly 12 times the rate, as compared to those with <25% retinal involvement (0.70/EY vs 0.06/EY; P = .001). Development of an RD was the greatest determinant of adverse visual outcomes, with 4% of eyes, that had experienced at least 1 RD, achieving a best-corrected visual acuity of ≥20/40 compared to 53% of eyes that never detached (P = .0003).

CONCLUSIONS

Poor outcomes in ARN were common in this cohort. RD confers the greatest risk of incident vision loss, and once 25% or more of the retina is involved the risk of RD and visual loss increases significantly.

Bilateral acute retinal necrosis after bilateral cataract surgery in an immunocompromised patient: a case report

PURPOSE

To report a case of bilateral varicella zoster virus (VZV)-associated acute retinal necrosis (ARN) occurring after both eyes sequential cataract surgery in an elderly immunocompromised patient.

METHODS

Medical records and investigation results of the patient were reviewed.

RESULTS

Patient experienced floaters and blurring of vision in both eyes 4 weeks after her second uncomplicated cataract surgery. Clinical signs of granulomatous keratic precipitates, prominent vitritis, retinitis and vascular thrombosis were noted in both eyes. Aqueous samples from both eyes were positive for VZV. Disease was treated with intravitreal foscarnet bilaterally and 10 days of systemic intravenous acyclovir (10 mg/kg) followed by oral valaciclovir 1 g three times daily. Final visual acuity at 4 months after initial presentation was 20/60 in both eyes with no retinal detachment noted.

CONCLUSIONS

Cataract surgery may have been the trigger for bilateral VZV-associated ARN. Immunocompromised patients can develop ARN and require close observation after cataract surgery. This is, to our knowledge, the first report of bilateral ARN following routine cataract surgery.

Valacyclovir as Initial Treatment for Acute Retinal Necrosis: A Pharmacokinetic Modeling and Simulation Study

PURPOSE

Acute retinal necrosis (ARN) is a feared complication of infectious retinitis most commonly caused by varicella zoster virus (VZV). We performed a pharmacokinetic modeling and simulation study by integrating the existing understanding of physiology with previously published data to evaluate the vitreal penetration of oral valacyclovir for the treatment of ARN, under various dosing scenarios.

METHOD

We compared different oral valacyclovir dosing regimens with intravenous acyclovir. The vitreous compartment was modeled as a peripheral compartment, and paired serum and vitreal acyclovir concentrations were obtained from previously published data of adult patients with ARN undergoing vitrectomy. The efficacy threshold for vitreal acyclovir concentrations was based on the previously reported IC₅₀ values for VZV.

RESULTS

Based on the minimum vitreal acyclovir concentrations (C_min) relative to the mean IC₅₀ for VZV, valacyclovir 1.5 g every 8 hours performed similarly to intravenous acyclovir 700 mg every 8 hours, with the minimum concentration (C_min) exceeding the mean IC₅₀ after the second dose. In contrast, the standard dosing regimen for herpes zoster, valacyclovir 1 g every 8 hours, performed inferiorly to the intravenous acyclovir regimen throughout the dosing interval.

CONCLUSIONS

Modeling and simulation data support oral valacyclovir for the treatment of ARN, although the required dosing exceeds the recommended FDA dose size for herpes zoster.

Necrotising herpetic retinopathies: a review and progressive outer retinal necrosis case report

Necrotising retinopathies can be visually devastating. Most often associated with the viral family Herpesviridae and seen in both immune-competent and immunocompromised hosts, possible complications of necrotising retinopathies include progressive retinal necrosis with or without macular involvement, optic neuropathy and ultimately, secondary retinal detachment. Examples include progressive outer retinal necrosis, acute retinal necrosis and cytomegaloviral retinitis. If diagnosed early and treated aggressively, visual complications can be prevented; however, there is no current consensus on the most appropriate antiviral regimen for each of the different varieties of necrotising herpetic retinopathy. This paper reviews aspects of varieties of necrotising herpetic retinopathy, including pathophysiology, treatment and diagnostic testing.

Clinical manifestation of self-limiting acute retinal necrosis

Background

The purpose of this paper was to present a case series of self-limiting, peripheral acute retinal necrosis and to demonstrate efficacy of treatment with valacyclovir in patients resistant to acyclovir. The diagnosis was made on ophthalmoscopic examination and positive serum tests for herpes viruses.

Material/Methods

Ten patients (6F and 4M) aged 19–55 years were diagnosed and treated for self-limiting acute retinal necrosis (ARN). The following endpoints were reported: visual outcomes, clinical features, disease progression, treatment, and complications. Patients received only symptomatic treatment because they did not consent to vitreous puncture.

Results

Peripheral, mild retinitis was diagnosed in all eyes at baseline. Initially, all patients were treated with systemic acyclovir (800 mg, 5 times a day), prednisone (typically 40–60 mg/day), and aspirin in an outpatient setting. In 6 patients, treatment was discontinued at 6 months due to complete resolution of the inflammatory process. Four patients with immune deficiency showed signs and symptoms of chronic inflammation. Two patients did not respond to acyclovir (2 non-responders); however, those patients were successfully treated with valacyclovir. Complete resolution of inflammatory lesions was observed in 8 patients. In 2 patients, the disease progressed despite treatment – 1 female patient after kidney transplant who stopped the prescribed medications, and 1 male patient with SLE and antiphospholipid syndrome who experienced breakthrough symptoms on-treatment. He died due to cerebral venous sinus thrombosis. Neurological complications (encephalitis and meningitis) were observed in 2 female patients. Prophylactic laser photocoagulation was performed in 1 subject.

Conclusions

A series of cases of self-limiting acute retinal necrosis (ARN) is presented. This clinical form of ARN can resemble toxoplasmic retinitis in some cases. Oral antiviral medications provide an effective alternative to intravenous formulations in patients with self-limiting ARN. Retinitis is associated with the risk of encephalitis.

Time profile of viral DNA in aqueous humor samples of patients treated for varicella-zoster virus acute retinal necrosis by use of quantitative real-time PCR

The objective of this study was to evaluate the kinetics of varicella-zoster virus (VZV) loads using quantitative PCR (qPCR) in patients treated for acute retinal necrosis (ARN). Six patients (52 ± 13 years old) with ARN syndrome were consecutively studied. Aqueous humor (AH) was sampled from both eyes of all patients for qPCR evaluation. The patients were treated with intravenous acyclovir and intravitreal injections of antiviral drugs. The mean follow-up time was 17.6 ± 16.4 months. Main outcome measures were the numbers of viral genome copies in the AH, assessed using real-time qPCR with hydrolysis probe technology with a threshold of detection of 200 copies/ml. Two main portions of the viral load curves were observed for each patient: a plateau phase (27.8 ± 24.9 days) and a decrease in the number of viral genome copies. The mean baseline viral load was 3.4 × 10(7) ± 4.45 × 10(7) copies/ml (6 × 10(6) to 1.2 × 10(8) copies/ml). The viral load decreased according to a logarithmic model, with a 50% reduction obtained in 3 ± 0.7 days. There was a significant viral load (>102 copies/ml) at 50 days after the onset of treatment, despite antiviral drugs. qPCR use demonstrated reproducible VZV DNA kinetics with a two-phase evolution: a plateau followed by a logarithmic decrease. These data suggest that high-dosage antiviral therapy administered for the conventional 10-day duration is insufficient for most patients. This series of patients responded with a similar decrease in viral load once treatment was initiated, and the data from these patients may be used to predict the responses of future patients.

Valacyclovir in the treatment of acute retinal necrosis

Background

To report the outcome of oral valacyclovir as the sole antiviral therapy for patients with acute retinal necrosis (ARN).

Methods

This study reports a retrospective, interventional case series of nine consecutive patients with ten eyes with newly diagnosed ARN treated with oral valacyclovir as the sole antiviral agent. Eight patients received oral valacyclovir 2 g tid (Valtrex, GlaxoSmithKline) and one patient with impaired renal function received oral 1 g tid. The main outcome measures were response to treatment, time to initial response to treatment, time to complete resolution of retinitis, best corrected visual acuity (BCVA) at final follow-up, retinal detachment and development of recurrent or second eye disease.

Results

Retinitis resolved in ten of ten (100%) affected eyes. The median time to initial detectable response was seven days and the median time to complete resolution was 21 days. A final BCVA of 20/40 or better was achieved in 6/10 (60%) of eyes. 3/10 eyes (30%) developed a retinal detachment. No patients developed either disease reactivation or second eye involvement over the course of the study (mean follow up 31 weeks, range 7 to 104 weeks).

Conclusions

Treatment with oral valacyclovir as the sole antiviral therapy resulted in complete resolution of retinitis. Final BCVA and retinal detachment rate were comparable with previously reported outcomes for intravenous acyclovir.

Efficacy and necessity of prophylactic vitrectomy for acute retinal necrosis syndrome

AIM

To compare the efficacy of prophylactic vitrectomy for acute retinal necrosis syndrome(ARN) with routine treatment in Chinese patients, thereby investigate the necessity of prophylactic vitrectomy for ARN.

METHODS

Thirty patients (37 eyes) were retrospectively included in this study. The eyes were divided into 2 groups by treatment, including routine treatment, which consisted of antiviral medication and vitrectomy after retinal detachment (RD) (n=21), and prophylactic vitrectomy, which consisted of antiviral medication and vitrectomy for the prevention of RD performed during the active inflammatory phase (n=16). The extent of necrosis was determined by fundus photographs at the time of presentation (for eyes with mild vitreous opacity) or the drawings in the operation records. Necrosis of the 37 eyes was divided into 3 grades, including peripheral, middle-peripheral and extensive. The follow-up period ranged from 8 to 57 months. Differences in visual acuity and necrosis between groups were identified using independent samples t-test.

RESULTS

Necrosis was more extensive in the routine treatment group than in the prophylactic vitrectomy group (P<0.05). In the routine treatment group, conservative treatment improved necrosis and prevented RD in 6 eyes (29%). Seven eyes (33%) obtained anatomical success, but retinal redetachment occurred in 8 eyes (57%). There were also 5 eyes (24%) developed ocular hypotony or atrophy. Ten eyes (48%) achieved equal or increased visual acuity. In the prophylactic vitrectomy group, RD occurred in 2 eyes (13%). Twelve eyes (75%) were completely anatomically successful, and 10 eyes underwent silicone oil removal. Only one eye (6%) became ocular hypotony. Fourteen eyes (88%) achieved equal or increased visual acuity. The prophylactic vitrectomy group achieved better vision trends than the routine treatment group (P<0.05). Eyes with peripheral necrosis had better visual outcomes than those with mid-peripheral (P<0.05) or extensive (P<0.05) necrosis. However, there was no significant difference between eyes with mid-peripheral and extensive necrosis (P=0.3008)

CONCLUSION

Prophylactic vitrectomy can prevent RD and improve the prognosis of ARN, making it an option for cases with rapidly progressing necrosis despite antiviral treatment and cases with moderate to extensive necrosis and severe vitreous opacity.

Acute retinal necrosis after Boston type I keratoprosthesis

A case report of a 68-year-old male who developed acute retinal necrosis (ARN) after Boston type I keratoprosthesis is presented. The procedure was performed for multiple graft failure secondary to herpetic keratitis. Clinical data including visual acuity, color fundus photography, fluorescein angiography, laboratory tests findings, and management are presented. After exclusion of other causes by laboratory workup, the patient was diagnosed with ARN most likely secondary to herpetic infection. Intravenous acyclovir and oral prednisolone were administered to the patient resulting in marked improvement in visual acuity and regression in the size of the retinitis. The patient eventually developed a soft eye and choroidal detachment with light perception vision. In patients with a history of herpetic keratitis or keratouveitis, it is highly advisable to maintain prophylactic systemic antiviral treatment before and after any ocular procedure such as the Boston keratoprosthesis.

[Acute retinal necrosis]

Acute retinal necrosis syndrome (ARN) is a rare retinitis caused by the herpes virus family, including herpes simplex virus and varicella zoster virus. ARN most commonly occurs in otherwise healthy patients of either sex at any age. It is characterized by an initial onset of episcleritis or scleritis, periorbital pain, and a frequently granulomatous anterior uveitis. The key criterion is a necrotizing retinitis starting in the periphery and spreading towards the posterior pole, associated with vitreous opacification. Optic neuropathy may also occur. A total of 75% of untreated eyes develop retinal detachment within the first two months after onset of the disease. Two out of three ARN cases show involvement of the fellow eye. Early intravenous antiviral therapy is mandatory to stop ARN progression. Peripheral retinal breaks can be treated by laser photocoagulation, thereby reducing the risk of retinal detachment. Vitreoretinal surgery is often required, and silicon oil is the tamponade of choice in ARN, resulting in good reattachment rates (90%). Visual prognosis, however, is guarded.