Clinical Alert

September 29, 1995

Clinical Alert to Ophthalmologists

Dear Colleague:

This letter is to inform you of findings from the Endophthalmitis Vitrectomy Study (EVS) that warrant your attention prior to publication of the results. This randomized, controlled clinical trial is supported by the National Eye Institute (NEI), part of the U.S. National Institutes of Health, and was conducted at 27 clinical centers nationwide.

The purpose of the EVS was:

• To determine the role of immediate pars plana vitrectomy in the management of endophthalmitis occurring after cataract surgery or secondary intraocular lens implantation.
• To determine the role of intravenous antibiotics in the management of endophthalmitis.

EVS patients had clinical evidence of bacterial endophthalmitis within six weeks of cataract surgery or secondary lens implantation. The involved eye had 1) either hypopyon or enough clouding of anterior chamber or vitreous media to obscure clear visualization of second-order retinal arterioles; 2) a cornea and anterior chamber in the involved eye clear enough to visualize some part of the iris; and, 3) a cornea clear enough to allow the possibility of pars plana vitrectomy. To enter the study, the patient had to have visual acuity worse than 20/50, but at least light perception.

The study received and analyzed outcome data from 420 patients who were randomly assigned to either immediate pars plana vitrectomy (VIT) or to vitreous tap or biopsy (TAP). They also were randomly assigned to either intravenous antibiotic treatment or to no intravenous treatment. All patients received intravitreal antibiotics.

A final outcome evaluation of visual acuity was assessed at 9-12 months and the results indicated that:

• There was no difference in final visual acuity or media clarity whether or not systemic antibiotics were employed.
• Patients who presented with hand motions or better vision did equally well whether they had immediate vitrectomy or immediate tap/biopsy.
• Patients who presented with vision of light perception only had much better visual results with immediate pars plana vitrectomy than with tap/biopsy. With vitrectomy, these patients were three times more likely to achieve 20/40 final vision (33% compared to 11%), twice as likely to achieve 20/100 final vision (56% compared to 30%), and less than one half as likely to incur severe visual loss of less than 5/200 (20% compared to 47%).

Based on the above results, we conclude that routine immediate vitrectomy was of no additional benefit in patients who met EVS entry criteria and presented with hand motions or better vision. However, immediate vitrectomy was of substantial benefit for those who presented with light perception only vision. In addition, systemic antibiotics provided no additional advantage to final visual outcome.

A scientific paper was submitted to the Archives of Ophthalmology for expedited review. The paper has been reviewed and revised and is expected to be published shortly. In addition, a symposium presenting the EVS results will occur at the annual meeting of the American Academy of Ophthalmology in Atlanta on Thursday, November 2, 1995, at 10:00 a.m.

Sincerely,


Carl Kupfer, M.D.
Director
National Eye Institute

Bernard H. Doft, M.D.
Study Chair, EVS
Retina-Vitreous Consultants
Pittsburgh, PA

Sheryl Kelsey, Ph.D.
Director, EVS Coordinating Center
Department of Epidemiology
University of Pittsburgh