Prophylactic Laser Photocoagulation and Vitrectomy for Acute Retinal Necrosis

Acute retinal necrosis (ARN) is a rare infectious retinitis which can potentially lead to devastating visual outcomes. ARN is diagnosed on the basis of the clinical appearance and disease course according to the diagnostic criteria proposed by the American Uveitis Society: (1) one or more foci of retinal necrosis with discrete borders in the peripheral retina; (2) rapid progression in the absence of antiviral therapy; (3) circumferential spread; (4) occlusive vasculopathy with arteriolar involvement; and (5) a prominent inflammatory reaction in the vitreous and anterior chambers.

Herpesvirus infection, especially varicella-zoster virus (VZV) and herpes simplex virus (HSV), was presumed to be the pathogenic agent in the pathogenesis of ARN. Medical treatment with systemic antiviral agent had been the base of the therapy of ARN for decades and such treatment usually result in regression of retinitis.

However, the visual outcome of ARN remains poor. The major causes of poor visual prognosis in ARN are retinal detachment and optic nerve or macular involvement by ischemic vasculopathy. Less frequent causes include macular hole formation, macular pucker, or hypotony. Rhegmatogenous retinal detachment may occur in 75 % of the untreated eyes. It may occur weeks to months after the onset of inflammation due to delayed formation of retinal breaks, which result from the combination of necrotic retina and vitreoretinal traction.

Therefore, application of argon laser retinopexy prophylactically posterior to necrotic retina or prophylactic vitrectomy to reduce inflammatory factors and the vitreoretinal traction had been used to protect the healthy area from detachment. However, the results were varied and there is no consensus on the efficacy and indications of those prophylactic procedures. We had applied the prophylactic procedure in our treatment for ARN. We aim to access the efficacy of the treatment strategy of ARN and the correlated factors to the outcomes.

Study Overview

• Status: Completed
• Conditions: Retinal Detachment; Vitrectomy; Acute Retinal Necrosis; Laser Photocoagulation

Detailed Description

Between 1995 and 2013, the charts of 20 patients (21 eyes) with a clinical diagnosis of ARN and a complete ophthalmic examination at National Taiwan University Hospital were reviewed. The study was approved by the Ethics Committee and Institutional Review Board of National Taiwan University Hospital.

The clinical data recorded included patient demographics, refractive error, lens status, best corrected visual acuity (BCVA), all treatments and retinal anatomical status. Visual acuities and examination findings were recorded at presentation and subsequent follow-up periods for at least 6 months. The area of retina involved was determined by review of retinal drawings and fundus photos by single reader.

All the patients were admitted for intravenous injection of Acyclovir (30mg/kg/day, in 3 divided doses) for 10-14 days and then shifted to oral Acyclovir (30mg/kg/day) at least for further 10-14 days. Systemic corticosteroid and Aspirin were also given. Prophylactic laser photocoagulation was arranged on normal retina to surround the posterior edge of the active lesions if the media was clear enough to approach. If vitritis persisted without improvement under systemic antiviral agent or retinal detachment was noted, vitrectomy would be performed. Visual acuities and retinal anatomical results were recorded during follow-up after procedures. The visual acuity was converted to logarithm of the minimum angle of resolution (logMAR) values for statistical analysis.

Statistical analysis The continuous values are expressed as means ± standard deviation (SD). The differences among the continuous variables were assessed using the Mann-Whitney U test. Non-continuous variables were analyzed by Fisher's exact test. The level of statistical significance was set at p < 0.05.

• Study Type: Observational
• Enrollment (Actual): 23

Contacts and Locations

Study Locations

• Taiwan
  • Taipei, Taiwan, 100
    • National Taiwan University Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 20 years to 80 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Patients with acute retinal necrosis

Description

Inclusion Criteria:

●Patients with clinical diagnosis of acute retinal necrosis.

Exclusion Criteria:

• Patients with history of retinal detachment.
• Patients with history of other causes of severe retinal atrophy or necrosis.
• HIV positive patients.

Study Plan

How is the study designed?

Design Details

• Observational Models: Case-Only
• Time Perspectives: Retrospective

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Best-corrected visual acuity	Best-corrected visual acuity during follow up and its correlated factors	1 year

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Retinal status	Retinal status by ophthalmoscopy to see the incidence of retinal detachment and its correlated factors	1 year

Collaborators and Investigators

• Sponsor: National Taiwan University Hospital
• Investigators: Principal Investigator: Chang-Ping Lin, MD, National Taiwan University Hospital

Study record dates

Study Major Dates

• Study Start: August 1, 2014
• Primary Completion (Actual): August 1, 2014
• Study Completion (Actual): August 1, 2014

Study Registration Dates

• First Submitted: August 20, 2014
• First Submitted That Met QC Criteria: August 20, 2014
• First Posted (Estimate): August 21, 2014

Study Record Updates

• Last Update Posted (Actual): April 26, 2018
• Last Update Submitted That Met QC Criteria: April 24, 2018
• Last Verified: August 1, 2014

More Information

Terms related to this study

• Keywords: Vitrectomy; Retinal detachment; Acute retinal necrosis; Laser photocoagulation
• Additional Relevant MeSH Terms: Pathologic Processes; Eye Diseases; Retinal Diseases; Retinitis; Necrosis; Retinal Detachment; Retinal Necrosis Syndrome, Acute
• Other Study ID Numbers: 201406118RIND