Endophthalmitis Vitrectomy Study (EVS)

Purpose

  • To determine the role of initial pars plana vitrectomy in the management of postoperative bacterial endophthalmitis.
  • To determine the role of intravenous antibiotics in the management of bacterial endophthalmitis.
  • To determine which factors, other than treatment, predict outcome in postoperative bacterial endophthalmitis.

Background

Endophthalmitis is a serious ocular infection that can result in blindness. Approximately 70 percent of cases occur as a direct complication of intraocular surgery. Current management requires culture of intraocular contents and administration of an antibiotic. Vitrectomy surgery, which may help to manage endophthalmitis by removing infecting organisms and their toxins, has been shown to be of value in various animal models of endophthalmitis. However, human studies have not shown an advantage to vitrectomy with intraocular antibiotics compared with intraocular antibiotics alone. 

In all large comparison studies to date, eyes with the worst initial presentations were the ones selected for vitrectomy. Because of the selection bias involved in determining which cases received vitrectomy, existing clinical information on the efficacy of the procedure for treating endophthalmitis is inconclusive. Determining the role of initial vitrectomy and the benefit or lack of benefit to certain subgroups of patients will help the clinician in the management of endophthalmitis. 

In addition, although systemic antibiotics have long been used in the management of endophthalmitis, there has been little evidence to support their efficacy, but there have been many reports of toxic systemic effects. In view of this, the role of systemic antibiotics in the management of endophthalmitis will be assessed.
 

Description

Endophthalmitis Vitrectomy Study (EVS) patients were randomized to one of two standard treatment strategies for the management of bacterial endophthalmitis. Eyes received either (1) initial pars plana vitrectomy with intravitreal antibiotics, followed by retap and reinjection at 36-60 hours for eyes that did poorly as defined in the study or (2) initial anterior chamber and vitreous tap/biopsy with injection of intravitreal antibiotics, followed by vitrectomy and reinjection at 36-60 hours in eyes doing poorly. In addition, all eyes were randomized to either treatment or no treatment with intravenous antibiotics.

Study end points were visual acuity and clarity of ocular media, the latter assessed both clinically and photographically. Each patientís initial end point assessment occurred at 3 months, after which procedures to improve vision, such as late vitrectomy for nonclearing ocular media, were an option. The final outcome assessment occurred at 9 months. Multiple centers cooperated by enrolling 420 eyes during the 42-month recruitment period.
 

Patient Eligibility

Men and women were eligible for entry into the EVS if they had clinical signs and symptoms of bacterial endophthalmitis in an eye that had cataract surgery or lens implantation within 6 weeks of onset of infection. The involved eye had to have either hypopyon or enough clouding of anterior chamber or vitreous media to obscure clear visualization of second-order arterioles, a cornea and anterior chamber in the involved eye clear enough to visualize some part of the iris, and a cornea clear enough to allow the possibility of pars plana vitrectomy. The eyes had to have a visual acuity of 20/50 or worse and light perception or better.

Patients were ineligible when the involved eye was known at the time of study entry to have had any pre-existing eye disease that limited best-corrected visual acuity to 20/100 or worse before development of cataract, any intraocular surgery before presentation (except for cataract extraction or lens implantation), any treatment for endophthalmitis before presenting at the study center, or any ocular or systemic condition that would prevent randomization to any of the study groups.
 

Results

There was no difference in final visual acuity or media clarity with or without systemic antibiotics. If patients presented with hand motions or better acuity, there was no difference in visual outcome with or without an immediate 3 port pars plana vitrectomy. However, vitrectomy tripled (33 percent compared with 11 percent) the frequency of achieving 20/40 or better acuity; approximately doubled (56 percent compared with 30 percent) the chance of achieving 20/100 or better acuity; and decreased by more than one-half (20 percent compared with 47 percent) the frequency of severe visual loss in the subgroup of patients who presented with visual acuity of light perception only. These differences were statistically significant.

Data from the EVS indicate that initial management for patients who meet EVS entry criteria should include 3 port pars plana vitrectomy if patients present with vision worse than hand motions, but that an initial vitreous tap/biopsy should generally be sufficient if presenting vision is hand motions or better. Systemic antibiotics were not of benefit in this study, although all patients should receive intravitreal antibiotics. In many cases, the management of postcataract extraction endophthalmitis may now require limited, if any, overnight hospital stay.
 

Publications

  • Doft BH, Wisniewski SR, Kelsey SF, Groer-Fitzgerald S, and the Endophthalmitis Vitrectomy Study Group: Diabetes and Postoperative Endophthalmitis in the Endophthalmitis Vitrectomy Study. Arch Ophthalmol 119: 650-656, 2001.

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  • Wisniewski SR, Kelsey SF, Groer-Fitzgerald D, Doft BH: Characteristics after Cataract Extraction or Secondary Lens Implantation among Patients Screened for the Endophthalmitis Vitrectomy Study. Ophthalmology 107: 1274-1282, 2000.

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  • Doft BH, Kelsey SF, Wisniewski SR, and the Endophthalmitis Vitrectomy Study Group: Retinal Detachment in the Endophthalmitis Vitrectomy Study. Arch Ophthalmol 118: 1661-1665, 2000.

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  • Han DP, Wisniewski SR, Kelsey SF, Doft BH, Barza M, Pavan PR, and the Endophthalmitis Vitrectomy Study Group: Microbiological Yields and Complication Rates of Vitreous Needle Aspiration Versus Mechanized Vitreous Biopsy in the Endophthalmitis Vitrectomy Study. Retina 19: 98-102, 1999.

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  • Han DP, Wisniewski SR, Kelsey SF, Doft BH, Barza M, Pavan PR: Reply Letter to the Editor from Stroh EM. Retina 19: 576-578, 1999.

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  • Doft BH, Kelsey SK, Wisniewski SR: Additional Procedures after the Initial Vitrectomy or Tap/Biopsy in the Endophthalmitis Vitrectomy Study. Ophthalmology 105: 707-716, 1998.

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  • Johnson MW, Doft BH, Kelsey SF, Barza M, Wilson LA, Barr CC, Wisniewski SR, and the Endophthalmitis Vitrectomy Study Group: The Endophthalmitis Vitrectomy Study: Relationship Between Clinical Presentation and Microbiological Spectrum. Ophthalmology Digest. Abstract 8-11, 1998.

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  • Doft BH: The Endophthalmitis Vitrectomy Study. Clinical Trials in Ophthalmology. A Summary and Practice Guide. Book Chapter published by Williams & Wilkins 97-111, 1998.

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  • Barza M, Pavan PR, Doft BH, Wisniewski SR, Wilson LA, Han DP, Kesley SF, EVS Study Group: Evaluation of Microbiologic Diagnostic Techniques in Postoperative Endophthalmitis in the EVS. Arch Ophthalmol 115: 1142-1150, 1997.

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  • Johnson MW, Doft BH, Kelsey SF, Barza M, Wilson LA, Barr CC, Wisniewski SR: The Endophthalmitis Vitrectomy Study: Relationship between clinical presentation and microbiologic spectrum. Ophthalmology 104: 261-272, 1997.

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  • Bannerman TL, Rhoden DL, McAllister SK, Miller JM, Wilson LA: The source of coagulase negative staphylococci in the Endophthalmitis Vitrectomy Study. Arch Ophthalmol 115: 357-361, 1997.

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  • Doft BH: Managing infectious endophthalmitis: Results of the EVS. American Academy of Ophthalmology, Focal Points, XV No. 3, 1997.

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  • Wisniewski SR, Hammer ME, Grizzard WS, Kelsey SF, Everett D, Packo KH, Yarian DL, Doft BH: The investigation of hospital charges related to the treatment of endophthalmitis in the Endophthalmitis Vitrectomy Study. Ophthalmology 104: 739-745, 1997.

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  • Barza M, Doft BH, Kelsey SF: Reply letters to the editor from Haimann MH, Weiss H, Miller J, Baker AS, Durand M. Arch Ophthalmol 114: 1026-1027, 1996.

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  • Doft BH, Barza M: Optimal management of postoperative endophthalmitis and results of the Endophthalmitis Vitrectomy Study. Current Opinion in Ophthalmology 7;111: 84-94, 1996.

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  • Doft BH, Kelsey SF, Wisniewski SR: Reply letters to the editor from LeClaire JE, Hanscom T. Arch Ophthalmol 114: 1030, 1996.

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  • Endophthalmitis Vitrectomy Study Group: The Endophthalmitis Vitrectomy Study: Microbiologic factors and visual outcome. Am J Ophthalmol 22: 830-846, 1996.

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  • Han DP, Wisniewski SR, Wilson LA, Barza M, Vine AK, Doft BH, Kelsey SF: The Endophthalmitis Vitrectomy Study: Spectrum and susceptibilities of microbiologic isolates. Am J Ophthalmol 122: 1-17, 1996.

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  • Kelsey SF, Doft BH: Reply letter to the editor from Flynn Jr. HW, Meredity TA. Arch Ophthalmol 114: 1028-1029, 1996.

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  • The Endophthalmitis Vitrectomy Study Group: Results of the Endophthalmitis Vitrectomy Study: A randomized trial of immediate vitrectomy and of intravenous antibiotics for the treatment of postoperative bacterial endophthalmitis. Arch Ophthalmol 113: 1479-1496, 1995.

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  • Doft BH, Kelsey SF, Wisniewski S, Metz DJ, Lobes L, Rinkoff J, Davis M, Kassoff A: Treatment of endophthalmitis after cataract extraction. Retina 14: 297-304, 1994.

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  • Doft BH, Barza M, Endophthalmitis Vitrectomy Study Group: Ceftazidime or Amikacin: Choice of intravitreal antimicrobials in the treatment of postoperative endophthalmitis. Letter to the Editor. Arch Ophthalmol 112: 17-18, 1994.

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  • Doft BH: The Endophthalmitis Vitrectomy Study. Editorial. Arch Ophthalmol 109: 487-489, 1991.

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  • Doft BH, Barza M: Reply letter to the editor from Haimann MH, Weiss H, and Miller JA. Arch Ophthalmol 109: 1051, 1991.
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