Endophthalmitis Management in India: a decade and half after the Endophthalmitis Vitrectomy Study
Taraprasad Das, Tapas R Padhi, and Savitri Sharma
L V Prasad Eye Institute, Bhubaneswar.
Correspondance: Taraprasad Das; tpd@lvpei.org
The current management of post cataract surgery acute endophthalmitis is greatly influenced by the Endophthalmitis Vitrectomy Study (EVS). The EVS was a multi centric randomized clinical trial that had asked two important questions: (1) Is vitrectomy necessary in all cases of post intraocular lens (IOL) acute bacterial endophthalmitis? and (2) Does systemic antibiotics help in these cases? The EVS recruited 420 patients with acute bacterial post IOL endophthalmitis in 24 centers in the USA. The study recommended that while intravitreal antibiotics must be given to all eyes, vitrectomy should be reserved for eyes with worse presenting vision (light perception, LP, only) and the study did not find any additional benefit of intravenous antibiotics. [1] The major findings of the EVS are listed in Table 1. Are these recommendations followed strictly a decade and half after its first publication in 1995?
We will discuss in this article the management strategies we currently practice at the L V Prasad Eye Institute vis-à-vis the EVS recommendations. These discussions are confined to management of acute post cataract surgery endophthalmitis alone and are based on the evidences generated in our institute over two decades. We will present them in the following seven major headings and finally sum up with the treatment algorithm. (I) Clinical Features; (II) Microbiology; (III) Choice of Intravitreal antibiotics; (IV) Rationale of Intravitreal corticosteroid; (V) Need for systemic antibiotics; and (VI) Cost effectiveness of vitrectomy, (VII) Risk factors, and (VIII) Treatment algorithm.
Table 1
EVS. Design and Recommendations
Enrollment |
1.Acute post operative endophthalmitis (within 6 weeks of surgery) |
Study Design |
RCT |
Study Drugs |
1.Intravit Antibiotics: Vancomycin (1 mg); Ceftazidime: 2.25 mg |
Recommendations |
1. Intravit antibiotics: Vancomycin + Ceftazidime to all eyes |
1. Clinical Features
Acute endophthalmitis manifests typically with acute loss of vision associated with pain, redness, lid edema, marked anterior chamber inflammation, anterior chamber fibrin/ hypopyon and vitreous inflammation. Chronic endophthalmitis typically has an indolent course and progressive inflammation. In the EVS visual acuity was less than 5/200 in 90% patients, LP in 26% patients, 86% patients had hypopyon and 25% patients did not have any pain. In our own study 91% patients had vision less than 5/200, 62% patients had LP, 76% patients had hypopyon and 25% patients did not have associated pain. We and others have attempted clinical grading of endophthalmitis related inflammation to quantify endophthalmitis severity. [2,3]
This could be used to possibly differentiate infective endophthalmitis from the toxic anterior segment syndrome (TASS). The principal differentiating features of infection from TASS are listed in Table 2. TASS can improve in time without a special treatment, whereas a diagnosis of endophthalmitis must be made as soon as possible in order to potentially achieve a good result.
The most confirmatory differentiating feature of TASS is the dramatic response to topical corticosteroids. Applied very frequently (every half hour to one hour) TASS eyes respond well to topical corticosteroids in 24 hours. In contrast frequent topical corticosteroids can only temporarily suppress inflammatory component in infective endophthalmitis. Despite these differentiating features it is unwise to take TASS lightly. Until a therapeutic response to topical corticosteroids is clearly present for several days, endophthalmitis should be the prime suspicion. We have earlier reported a series of such cases, and for lack of proper terminology, we had named it “Presumed non-infectious endophthalmitis”. In these series 23 of 27 eyes responded favorably medical therapy alone. [4] The medical therapy consisted of topical corticosteroids in all, topical and systemic antibiotics in 6 patients each (22.2%), and systemic corticosteroid in 12 patients (44.4%).
Table 2
Differentiating Features between TASS and Infective Endophthalmitis
Features |
TASS |
Infective Endophthalmitis |
Timing of Disease |
Always appears on first post operative day |
Usually appears little later unless there is fulminant infection |
Pain |
Absent |
Could be present |
Lid edema |
Uncommon |
Possible |
Conj congestion |
Minimal |
Always |
Corneal Edema |
Limbus to limbus corneal edema |
Patchy corneal edema |
Iris |
Fixed and dilated pupil |
Variable pupil size |
Intraocular Pressure |
Raised |
Variable |
Therapeutic response to topical corticosteroid |
Dramatic |
Temporary suppression of inflammation |
2. Microbiology
The final confirmation of infection is obtained from the microbiology laboratory. Undiluted vitreous from an infected eye is the source for microbiology studies. The anterior chamber fluid is not as good a source as the undiluted vitreous. Microscopy uses a variety of stains such as Gram, Giemsa and calcoflur white. The culture media include blood agar, chocolate agar, thioglycollate broth and brain heart infusion for bacteria and potato dextrose agar and Sabouraud dextrose agar for fungi. While the culture is more confirmatory, microscopy of the undiluted vitreous should not be discounted for the simple reason that the initial treatment is either empirical or is based on the vitreous smear report; the culture report is available usually day later. We have reported that more than six polymorphs per high power field are indicative of infection. [5]
