Decrease in the risk of bilateral acute retinal necrosis by acyclovir therapy

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.

Comparing Treatment of Acute Retinal Necrosis With Either Oral Valacyclovir or Intravenous Acyclovir

PURPOSE

To compare the visual outcomes of patients with acute retinal necrosis (ARN) treated initially with intravenous acyclovir vs oral valacyclovir therapy.

DESIGN

Retrospective, comparative, interventional case series.

METHODS

Sixty-two patients (68 eyes) with ARN, treated at Moorfields Eye Hospital (United Kingdom) between 1992 and 2016, were identified through the hospital's electronic database. Exclusion criteria included insufficient patient records or follow-up (<150 days). Fifty-six patients had unilateral ARN, while 6 had bilateral ARN. Patients who received intravenous acyclovir on diagnosis (n = 33) were compared with patients treated with oral valacyclovir (n = 29) across outcomes including best-corrected visual acuity, retinal detachment, severe vision loss, and other complications. The impact of adjunctive intravitreal antiviral and prophylactic barrier laser treatment was also assessed.

RESULTS

Change in best-corrected visual acuity was not significantly different for eyes treated initially with intravenous therapy vs oral therapy over 5 years of follow-up data (P = .16). There was no difference in the rates of severe vision loss between the 2 groups (46% and 59%, respectively, P = .18), or of those eyes retaining good vision (28% vs 31%, respectively, P = .80). Retinal detachment occurred in 63% of cases and did not differ across treatment groups (62% vs 66%, respectively, P = .67). Barrier laser and intravitreal therapy had no effect on retinal detachment rate in either group.

CONCLUSION

Oral valacyclovir is clinically equivalent to intravenous therapy in the management of ARN. Oral valacyclovir as an outpatient therapy-with or without intravitreal foscarnet-can therefore be considered as an acceptable alternative to inpatient therapy required for intravenous treatment.

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.

The necessity and optimal time for performing pars plana vitrectomy in acute retinal necrosis patients

BACKGROUND

To compare the efficacy of pars plana vitrectomy (PPV) at different time points to treat acute retinal necrosis (ARN) and to investigate the necessity of PPV for ARN.

METHODS

A retrospective review of the treatment options and outcomes of the ARN patients was performed. Thirty ARN patients (34 eyes) were included in this study. The eyes were divided into 3 groups depending on the treatment administered. In the medically treated group, there was no retinal detachment (RD) at the first visit. The routine group patients were treated with systemic antiviral medications, as well as with intravitreal antiviral injections. In the early PPV treatment group, there was no RD at the first visit. The early PPV treatment group patients were treated with systemic antiviral medications and PPV plus silicone oil tamponade and intravitreal injection. In the PPV group, there was RD at the first visit. The PPV group patients were treated with systemic antiviral medications and PPV plus silicone oil tamponade and intravitreal injection.

RESULTS

In the medically treated group, the mean baseline best corrected visual acuity (BCVA) (logMAR) was 1.38 ± 0.35. The BCVA was 1.21 ± 0.36 at the last visit for the medically treated group. In this group, one eye (12.5%) developed RD after 1 month of treatment. In the early PPV treatment group, the mean BCVA (logMAR) was 1.68 ± 0.26. The BCVA was 1.83 ± 0.21 at the last visit for the early PPV group. In this group, five eyes (29.4%) had recurrent RD before silicone oil removal. In the PPV group, the mean BCVA (logMAR) was 2.0 ± 0.35. The BCVA was 1.72 ± 0.34 at the last visit for the PPV group. In this group, one eye (11.1%) had recurrent RD before silicone oil removal. There were no significant differences among the three groups in the baseline BCVA and the BCVA at the last visit (p>0.05). There were no significant differences between the early PPV group and the PPV group in the recurrent RD rates (p = 0.38).

CONCLUSIONS

Prophylactic PPV showed no difference in recurrent RD rates or better BCVA. Therefore, prophylactic vitrectomy cannot prevent RD nor improve the prognosis of ARN based on our research.

Concomitant Intravitreal Ganciclovir and Dexamethasone Therapy in the Management of Acute Retinal Necrosis in a Patient Previously Treated with Oral Famciclovir

Several treatments have been reported for acute retinal necrosis (ARN). We report a case of treatment with intravitreal injection of ganciclovir and dexamethasone in addition to oral valacyclovir in a patient who was previously treated with oral famciclovir for ipsilateral herpes zoster ophthalmicus (HZO).

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.

Efficacy of Oral Valacyclovir Treatment in a Case with Acute Retinal Necrosis

Acute retinal necrosis (ARN) is a rapidly progressive disease with poor prognosis, leading to visual loss in most cases. Rapid diagnosis and early anti-viral treatment significantly affect the course and prognosis of the disease. In this case report, we present a 34-year-old female patient referred to our clinic with symptoms of blurred vision and ocular pain diagnosed as acute glaucoma elsewhere. A clinical diagnosis of ARN was made and anti-viral treatment was started immediately. We herein describe our treatment approach to this particular case and discuss previously reported treatment modalities.

Diagnosis and Treatment of Acute Retinal Necrosis: A Report by the American Academy of Ophthalmology

PURPOSE

To evaluate the available evidence in peer-reviewed publications about the diagnosis and treatment of acute retinal necrosis (ARN).

METHODS

Literature searches of the PubMed and Cochrane Library databases were last conducted on July 27, 2016. The searches identified 216 unique citations, and 49 articles of possible clinical relevance were reviewed in full text. Of these 49 articles, 27 were deemed sufficiently relevant or of interest, and they were rated according to strength of evidence. An additional 6 articles were identified from the reference lists of these articles and included. All 33 studies were retrospective.

RESULTS

Polymerase chain reaction (PCR) testing of aqueous or vitreous humor was positive for herpes simplex virus (HSV) or varicella zoster virus (VZV) in 79% to 100% of cases of suspected ARN. Aqueous and vitreous specimens are both sensitive and specific. There is level II and III evidence supporting the use of intravenous and oral antiviral therapy for the treatment of ARN. Data suggest that equivalent plasma drug levels of acyclovir can be achieved after administration of oral valacyclovir or intravenous acyclovir. There is level II and III evidence suggesting that the combination of intravitreal foscarnet and systemic antiviral therapy may have greater therapeutic efficacy than systemic therapy alone. The effectiveness of prophylactic laser or early pars plana vitrectomy (PPV) in preventing retinal detachment (RD) remains unclear.

CONCLUSIONS

Polymerase chain reaction testing of ocular fluid is useful in supporting a clinical diagnosis of ARN, but treatment should not be delayed while awaiting PCR results. Initial oral or intravenous antiviral therapy is effective in treating ARN. The adjunctive use of intravitreal foscarnet may be more effective than systemic therapy alone. The role of prophylactic laser retinopexy or early PPV is unknown at this time.

Fulminant bilateral acute retinal necrosis syndrome associated with viral encephalitis: A case report

Herpes simplex virus (HSV) is the most common cause of acute viral encephalitis. Acute retinal necrosis (ARN) is a rapidly progressing and potentially blinding eye disease that may be induced by HSV. The present case study reports the very rare case of a patient with herpes simplex encephalitis (HSE) combined with acute retinal necrosis (ARN). A 47-year-old woman was admitted to hospital with persistent high fever and somnolence for 5 days. Magnetic resonance imaging showed abnormal signals in the right medial temporal lobes, and HSV-1 was identified in the serum and cerebrospinal fluid. Five days later, despite treatment with intravenous acyclovir and partial improvement in consciousness, the patient suddenly developed blurred vision and bilateral visual pain. Fundus fluorescence angiography revealed bilateral vessel obstruction and flaky reduced fluorescence. ARN was diagnosed clinically. Dexamethasone was administered as an anti-inflammatory adjunct to intravenous acyclovir therapy. The visual acuity of the patient was reduced to mere light perception a further 4 days later. The present case indicates that HSE may be complicated with ARN, causing a reduction in visual acuity to mere light perception within a very short time.

Delayed recurrence of acute retinal necrosis (ARN): A case series

PURPOSE

To report five cases of acute retinal necrosis (ARN) that reactivated in the same eye or presented in the contralateral eye between two and nineteen years after the initial episode of acute retinal necrosis.

CASES

Five patients with a previous history of ARN developed recurrent ARN infection following a lengthy latency period. In all five patients who initially presented with unilateral disease, four developed infection in the contralateral eye and one developed recurrent infection in the ipsilateral eye. Latency periods ranged from two to nineteen years, and final visual acuity in the affected eyes ranged from 20/30 to no light perception. Each patient was treated with antiviral medication for both the initial infection and for subsequent reactivations, but was not on long-term prophylaxis at the time of recurrent disease.

CONCLUSION

Although rare, delayed onset reactivation of ARN can occur in either the same eye or contralateral eye despite adequate treatment. While contralateral spread of initial infection is fairly common, these reactivations rarely occur more than six weeks after initial infection. Currently there are no guidelines for use of prophylactic antiviral medication to prevent late recurrence of ARN.

Long-term outcomes in patients undergoing vitrectomy for retinal detachment due to viral retinitis

Purpose

To determine the outcomes in patients with rhegmatogenous retinal detachment (RRD) secondary to viral retinitis.

Patients and methods

This was a retrospective, consecutive, noncomparative, interventional case series of 12 eyes in ten patients with RRD secondary to viral retinitis. Results of vitreous or aqueous biopsy, effect of antiviral therapeutics, time to retinal detachment, course of visual acuity, and anatomic and surgical outcomes were investigated.

Results

There were 1,259 cases of RRD during the study period, with 12 cases of RRD secondary to viral retinitis (prevalence of 0.95%). Follow-up was available for a mean period of 4.4 years. Varicella zoster virus was detected in six eyes, herpes simplex virus in two eyes, and cytomegalovirus in two eyes. Eight patients were treated with oral valacyclovir and two patients with intravenous acyclovir. Lack of optic nerve involvement correlated with improved final visual acuity of 20/100 or greater. Pars plana vitrectomy (n=12), silicone-oil tamponade (n=11), and scleral buckling (n=10) provided successful anatomic retinal reattachment in all cases, with no recurrent retinal detachment and no cases of hypotony during the follow-up period.

Conclusion

Varicella zoster virus was the most frequent cause of viral retinitis, and lack of optic nerve involvement was predictive of a favorable visual acuity prognosis. Vitrectomy with silicone-oil tamponade and scleral buckle placement provided stable anatomical outcomes.

Current aspects on the management of viral uveitis in immunocompetent individuals

Viruses are a fundamental etiology of ocular inflammation, which may affect all structures of the organ. Advances in molecular diagnostics reveal an increasingly broader spectrum of virus-associated intraocular inflammation, including all members of the herpes family, rubella virus, and other more rare causes such as Epstein–Barr and chikungunya virus. In particular, viruses of the herpes family are important causes of anterior and posterior uveitis. Owing to their often fulminant clinical course and persistence in ocular tissues, a clear differential diagnosis between alpha- and beta-type herpes viruses is essential to guide acute and long-term treatment. Here, we review the epidemiology, clinical, and laboratory findings of virus-associated uveitis with emphasis on their therapy and management and include our own experience.

Acute Retinal Necrosis with Multiple Viral Infections: A Case Report

A 52-year-old male presented with acute retinal necrosis in his left eye. Slit lamp examination revealed stellate keratic precipitates and cells in the anterior chamber and vitreous. Funduscopy of his left eye revealed multiple yellow deposits. Pathological examination of the vitreous showed both small, reactive lymphocytes and a few macrophages. IL-6 and IFN-γ were elevated in the vitreous. Microdissected macrophages from the vitreous revealed DNAs from multiple viruses. The patient responded to oral valacyclovir. We conclude that multiple viral infections can be involved in the pathogenesis of acute retinal necrosis and that adequate anti-viral therapy has a beneficial effect on disease progression. However, retinal detachment can be a consequence for a poor visual outcome.

Pattern of Acute Retinal Necrosis in a Referral Center in Tunisia, North Africa

PURPOSE

To describe the pattern of acute retinal necrosis (ARN) syndrome in a referral center in Tunisia.

METHODS

Retrospective review of the charts of 12 patients (12 eyes).

RESULTS

Necrotizing retinitis involved >50% of the retina in 33.3% of eyes. Polymerase chain reaction on aqueous humor sample identified herpes simplex virus-1 in 4 eyes (33.3%) and varicella zoster virus in 3 eyes (25%), and was negative in 5 eyes (41.7%). All patients received intravenous acyclovir, followed by oral antivirals. Follow-up ranged from 6 to 16 months. Retinal detachment (RD) occurred in 3 eyes (25%), but no patient developed bilateral ARN. Final visual acuity was 20/200 or worse in 7 eyes (58.3%). Delay in diagnosis (p = 0.015), macular involvement (p = 0.045), development of RD (p = 0.018), and 25-50% of retinal involvement (p = 0.045) were associated with a worse visual outcome.

CONCLUSION

ARN carries poor visual prognosis in Tunisia.

Herpes simplex virus type 1 encephalitis and unusual retinitis in a patient with systemic lupus erythematosus

In this report we discuss a case of a patient with systemic lupus erythematosus who developed herpes simplex virus type 1(HSV-1) infection presenting with encephalitis as well as necrotic and non-necrotic retinitis. The patient presented with typical clinical symptoms and radiologic abnormalities consistent with HSV-1 encephalitis and HSV-1 retinitis in patients with HIV infection, but lacked cerebrospinal fluid pleocytosis and had bilateral retinitis with poor visual acuity. To the best of our knowledge, this is the first such case reported in the literature.

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.

Acute retinal necrosis in the United Kingdom: results of a prospective surveillance study

BACKGROUND

To determine the incidence of acute retinal necrosis (ARN) in the United Kingdom and to describe the demographics, management, and visual outcome in these patients.

METHODS

This was a prospective study carried out by the British Ophthalmological Surveillance Unit (BOSU) between September 2007 and October 2008. Initial and 6-month questionnaires were sent to UK ophthalmologists who reported cases of ARN via the monthly BOSU report card system.

RESULTS

In all, 45 confirmed cases (52 eyes) of ARN were reported in the 14-month study period, giving a minimum incidence of 0.63 cases per million population per year. There were 20 females and 25 males. Age ranged from 10 to 94 years. Eight patients had a history of herpetic CNS disease. Aqueous sampling was carried out in 13 patients, vitreous in 27, and cerebrospinal fluid (CSF) in 4. Varicella-zoster virus followed by herpes simplex were the most common causative agents. Treatment in 76% of the cases was with intravenous antivirals; however, 24% received only oral antivirals. In all, 47% of patients had intravitreal antiviral therapy. Visual outcome at 6 months was <6/60 in 48% of the affected eyes.

CONCLUSION

The minimum incidence of ARN in the UK is 0.63 cases per million. Patients with a history of herpetic CNS disease should be warned to immediately report any visual symptoms. There is increased use of oral and intravitreal antivirals in initial treatment.

Acute retinal necrosis associated optic neuropathy

Acute retinal necrosis (ARN) syndrome is characterized by severe intraocular inflammation, occlusive vasculopathy and peripheral retinal necrosis. Vision threatening complications of this syndrome include retinal detachment, macular oedema and ischaemia and optic neuropathy. Optic nerve involvement may be the presenting sign of ARN and this condition should be included in the differential diagnosis of acute papillitis. Several mechanisms may lead to ARN associated optic neuropathy including vasculitis, optic nerve ischaemia and direct optic nerve invasion by the herpes virus. We review optic nerve involvement during ARN and present its incidence, pathogenesis, differential diagnosis and treatment.

Intravitreal ganciclovir and dexamethasone as adjunctive therapy in the management of acute retinal necrosis caused by varicella zoster virus

A 40-year-old man presented with a visual acuity of 20/400 in his right eye due to acute retinal necrosis involving two inferior quadrants. Diagnostic vitreous tap was positive for varicella zoster virus and he received intravitreal injections of ganciclovir (2 mg/0.1 mL) and dexamethasone (400 mcg/0.1 mL). Oral prednisone was added on day 3 and tapered over 3 months. Lesions showed pigmentation around day 5 and healed by day 9. He developed vitreous hemorrhage 5 months after presentation and was treated with 25-gauge pars plana vitrectomy combined with panretinal photocoagulation. Final follow-up at 7 months showed a visual acuity of 20/30, mild optic atrophy, narrow arteries, healed retinal lesions, and good panretinal photocoagulation. Intravitreal injections of dexamethasone and ganciclovir may have a role as an adjunctive therapy in the management of patients with acute retinal necrosis, particularly those caused by varicella zoster virus.

Kyrieleis plaques associated with acute retinal necrosis from herpes simplex virus type 2

PURPOSE

To present the case of a 19-year-old woman with acute retinal necrosis syndrome due to herpes simplex virus type 2, who developed segmental periarterial (Kyrieleis) plaques six and one half weeks into her clinical course.

METHODS

Retrospective case report.

PATIENTS

Single patient with the diagnosis of acute retinal necrosis syndrome.

RESULTS

The patient's vitreous biopsy was positive by polymerase chain reaction for herpes simplex virus type 2.

DISCUSSION

Kyrieleis plaques have been found in the setting of toxoplasmosis, tuberculosis, syphilis, rickettsial disease, herpes zoster virus, intraocular lymphoma, and idiopathic branch retinal artery occlusions. The differential diagnosis for these periarterial plaques should also include herpes simplex virus type 2.

Focal posterior pole viral retinitis

PURPOSE

To describe the clinical features of an atypical form of viral retinitis in immunocompetent patients.

METHODS

This was a retrospective noncomparative case series. The charts of 8 patients diagnosed with and treated for focal posterior viral retinitis were reviewed. Clinical and demographic features were evaluated. All the patients had extensive laboratory tests, fundus fluorescein angiography, optical coherence tomography of macula, and polymerase chain reaction of vitreous.

RESULTS

All the patients were referred to our Uveitis Service from other hospitals, as their uveitis symptoms deteriorated in spite of treatment. The mean age of 4 male and 4 female patients was 32.1 years (range, 22-42 years). The mean follow-up period was 10 months (range, 6-18 months). All of the patients had unilateral disease. Polymerase chain reaction analysis of vitreous specimen was positive for herpes simplex virus-1 in 5 patients and varicella zoster virus in 3 patients. Retinitis resolved after systemic acyclovir treatment in all patients.

CONCLUSIONS

Viral etiology must be borne in mind in the differential diagnosis of atypical retinitis. It can be a milder form of viral retinitis like focal viral retinitis, as mentioned in this study. The prognosis of this disease is better than the other forms of necrotizing retinopathies involving a larger area of retina.

[Acute retinal necrosis from the virologist's perspective]

Acute retinal necrosis occurs in approximately one per million persons per year and is caused in approximately 70% of the cases by the varicella zoster virus or in about 30% of the cases by herpes simplex virus. The early diagnosis is primarily based on virus-specific polymerase chain reaction in fluid from the anterior chamber or vitreous humor and can be supported by the determination of specific antibody titers from fluid and serum. Virus detection provides the basis for early causative therapy which limits disease progression and risk of complications. Retinal infections by varicella zoster virus or herpes simplex virus are treated with aciclovir, ganciclovir, or famciclovir. Ganciclovir and valganciclovir are used for the therapy of retinal cytomegalovirus infections. In the case of resistance development, foscarnet or cidofovir are available as second line antiviral drugs. The early use of specific antiviral agents is a crucial prerequisite for optimized therapy of acute retinal necrosis.

CASE REPORT Vitrectomy and Silicone Oil Tamponade as an Initial Surgery for Retinal Detachment After Acute Retinal Necrosis Syndrome

PURPOSE

To show the feasibility of vitrectomy and silicone oil tamponade as an initial surgical procedure for retinal detachments with multiple tears that develop after the fulminant type of acute retinal necrosis syndrome.

METHODS

In a prospective noncomparative interventional case series, vitrectomy, silicone oil tamponade, and encircling scleral buckling with a solid silicone, combined with phacoemulsification and intraocular lens implantation (except for one pseudophakic patient [Case 2]), were performed in three consecutive patients during the four-year period from 1999 to 2002. These patients had developed retinal detachment with multiple retinal tears after the resolution of acute retinal necrosis syndrome. As an initial standard treatment for acute retinal necrosis syndrome, all patients received maximum-dose intravenous acyclovir (1500 mg daily) for two weeks combined with intravenous prednisolone tapered from 200 mg daily.

RESULTS

Case 1 was a 65-year-old woman who developed retinal detachment 44 days after the onset of acute retinal necrosis syndrome; Case 2, a 79-year-old man, developed retinal detachment 51 days after the onset; and Case 3, a 59-year-old man, developed retinal detachment 70 days after the onset. Before surgery, all patients showed multiple tears scattered on the detached atrophic retina extending over the entire midperipheral fundus with vitreoretinal adhesions and vitreous opacity. The retina was reattached during the initial surgery. The patients showed no recurrence of retinal detachment and maintained a visual acuity of 20/200 or 20/100 during the one- to three-year follow-up period.

CONCLUSIONS

Vitrectomy and silicone oil tamponade could be a treatment option as the initial surgical procedure for retinal detachments that develop after the fulminant type of acute retinal necrosis syndrome.

Vitreous penetration of orally administered famciclovir

PURPOSE

To determine the vitreous penetration of penciclovir (Denavir; GlaxoSmithKline, Philadelphia, Pennsylvania, USA) after oral administration of the prodrug famciclovir (Famvir; Novartis Pharmaceuticals Corp, East Hanover, New Jersey, USA).

DESIGN

Prospective interventional case series.

METHODS

Ten patients undergoing elective pars plana vitrectomy at a single institution were enrolled to take 3 oral doses of famciclovir 500 mg the day preceding surgery and a fourth dose on the morning of surgery. Blood and undiluted vitreous samples were acquired from each patient during surgery. High-performance liquid chromatography was used to determine the concentration of penciclovir in each sample. Exclusion criteria included prior vitrectomy, compromised blood-retina barrier, renal or hepatic disease, human immunodeficiency virus infection, bone marrow or renal transplantation, pregnancy or breastfeeding, history of adverse reaction or allergy to famciclovir or penciclovir, and antiviral, probenecid, or cimetidine use within 1 month of surgery.

RESULTS

Ten eyes of 10 patients ranging in age from 26 to 82 were included. All patients had normal renal and hepatic function as determined by history and laboratory values. Mean serum penciclovir concentration +/- standard deviation was 4.45 +/- 1.31 microg/ml (range, 2.51 to 6.34 microg/ml). Mean vitreous penciclovir concentration was 1.21 +/- 0.38 microg/ml (range, 0.39 to 1.88 microg/ml). Mean vitreous-to-serum concentration ratio of penciclovir was 0.28 +/- 0.09 (range, 0.16 to 0.41).

CONCLUSIONS

Oral administration of famciclovir results in vitreous concentrations of penciclovir within the inhibitory ranges for herpes simplex 1, herpes simplex 2, and varicella zoster virus. Oral famciclovir may be a reasonable alternative to intravenous acyclovir (Zovirax; GlaxoSmithKline) in the treatment of acute retinal necrosis, especially in cases of acyclovir resistance or patient inability to tolerate prolonged intravenous treatment.

Acute retinal necrosis: a national population-based study to assess the incidence, methods of diagnosis, treatment strategies and outcomes in the UK

AIM

To determine the incidence, methods of diagnosis, treatment strategies and outcomes for acute retinal necrosis (ARN) in the UK.

METHODS

A 12-month active case ascertainment study was carried out between March 2001 and March 2002 to record cases of ARN presenting to ophthalmologists via the British Ophthalmological Surveillance Unit (BOSU) reporting system. Questionnaires were sent to the reporting consultants, requesting data on patient characteristics, presentation, clinical findings, investigations and treatment. Diagnosis was made using the American Uveitis Society diagnostic criteria. Further questionnaires were sent at 2 weeks and 6 months to assess outcome and therapies.

RESULTS

74 cases of ARN were reported by 58 consultants between March 2001 and March 2002. Questionnaires were returned for 49 cases (66.2%), of which 18 (36.7%) were excluded. Of the 31 cases included, 22 (71.0%) were male and 9 (29.0%) were female. The age range was 13 to 85 years (mean 54.3 years). 28 cases (90.3%) were unilateral, with 3 patients (9.7%) presenting with bilateral ARN. An aqueous or vitreous biopsy was performed in only 18 patients, with one patient having both. Herpes viral DNA analysis was performed on all 19 biopsies, with identification of the viral DNA in 16; results from 3 biopsies were not documented. Varicella zoster virus (VZV) was the commonest cause identified in 10 patients (56%). Of the 31 subjects, 27 (87.1%) were treated for ARN with systemic antiviral treatment: with intravenous antiviral in 23 cases (85.2%) and oral antiviral in 4 cases (14.8%). 21 of these patients went on to receive oral antiviral maintenance therapy. In addition to antiviral treatment, systemic steroids were given to 16 subjects (51.6%). Surgical intervention for retinal detachment was performed on 5 patients.

CONCLUSIONS

During the 12-month study period, 31 cases of ARN met the diagnostic criteria set by the American Uveitis Society. The incidence in the UK based on this study is approximately 1 case per 1.6 to 2.0 million population per year. We have ascertained that the management of ARN throughout the UK is variable, suggesting that national guidelines would be of benefit.

Treatment of Acute Retinal Necrosis Syndrome with Oral Antiviral Medications

OBJECTIVE

Acute retinal necrosis (ARN) is a distinct ocular viral syndrome traditionally treated with intravenous acyclovir followed by oral acyclovir. We investigated the use of the oral antiviral medications valacyclovir and famciclovir as the sole treatment for patients with newly diagnosed ARN syndrome.

DESIGN

Retrospective, uncontrolled, interventional case series.

PARTICIPANTS

Eight consecutive patients with newly diagnosed ARN treated solely with oral antiviral medications.

INTERVENTION

All patients received famciclovir or valacyclovir without antecedent intravenous therapy. One patient with bilateral ARN treated with famciclovir received a single intravitreal injection of foscarnet in the more severely involved eye.

MAIN OUTCOME MEASURES

Clinically and photographically documented complete resolution of retinitis and best-corrected visual acuity on final follow-up.

RESULTS

Active retinitis resolved completely in 10/10 (100%) affected eyes. Initial response to treatment was seen as early as 4 days (in 5 eyes), with a median time to complete resolution of 14 days. At the last examination, visual acuity was improved (> or = 2 Snellen lines) in 6 (60%) eyes, stable in 2 (20%) eyes, and worse in 2 (20%) eyes. Over a mean follow-up of 36 weeks (range, 7-72 weeks), 3 eyes developed rhegmatogenous retinal detachment that was successfully repaired with 1 vitrectomy surgery. No patient with initially unilateral involvement developed disease in the contralateral eye.

CONCLUSIONS

In this pilot study, the use of the oral drugs valacyclovir and famciclovir resulted in complete regression of herpetic necrotizing retinitis. Additional studies are necessary to evaluate the role of these antiherpetic medications in the treatment of the ARN syndrome.