|Year : 2001 | Volume
| Issue : 1 | Page : 1-2
Is continuous research necessary in management of post cataract surgery endophthalmitis!
L.V. Prasad Eye Institute, L.V. Prasad Marg, Banjara Hills, Hyderabad - 500 034, India
L.V. Prasad Eye Institute, L.V. Prasad Marg, Banjara Hills, Hyderabad - 500 034, India
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Das T. Is continuous research necessary in management of post cataract surgery endophthalmitis!. Indian J Ophthalmol 2001;49:1-2
Endophthalmitis is one of the most devastating conditions to occur after cataract surgery. With this event the hopes of the patient vanish, confidence of the operating surgeon is shattered, and there is always a lurking fear of possible medico-legal implications. With advances in clinical and basic research in understanding and managing endophthalmitis, the incidence has considerably reduced in last five decades from 2% to less than 0.1% in most developed countries. Several individuals and groups have contributed in this quest. Peyman et al studied the pharmacokinetic of intravitreal antibiotics and corticosteroids; Speaker et al established that conjunctival bacteria are an important source of post operative infection, and that preoperative preparation of the conjunctiva with 5% povidone iodine could effectively sterilize the conjunctiva. Today intravitreal antibiotics coupled with vitrectomy in selected cases is the mainstay of treatment. Moreover, there is universal acceptance of preoperative preparation of the ocular surface with povidone iodine before intraocular surgery.
One of the most elegant studies to date in post cataract surgery endophthalmitis is EVS - the Endophthalmitis Vitrectomy Study. Chaired by Bernard Doft this four- year multi center prospective clinical trial involving 420 patients examined three important issues: systemic antibiotics, intravitreal antibiotics, and pars plana vitrectomy in management of endophthalmitis. The main conclusions of the EVS were (a) systemic antibiotics are not required; (b) intravitreal antibiotics (vancomycin and ceftazidime) are the mainstay of treatment; (c) the eyes with vision of hand motions or better do not need vitrecomy, and could benefit from vitreous tap and intravitreal antibiotics. These findings have several clinical and economic implications. According to the EVS management protocol the patients need not stay in the hospital for several days since intravenous injection of antibiotics is not required. The intervention is cheaper because vitrectomy is indicated only in selected cases. All the patients need not mandatorily seek treatment with a retina specialist since a general ophthalmologist could manage with intravitreal antibiotics alone. Thus the treatment is simpler and cheaper, without compromising the final visual outcome.
In clinical practice, randomized clinical trials (RCT) enormously influence the decision making. These trials are well designed, well conducted, and recruit large enough number of patients to obtain a statistically validated answer. While at one end of the spectrum this information helps clinicians arrive at a scientific validated conclusion, at the other end these studies tend to retard, if not totally discourage further clinical, operational, and basic research. A good example to quote will be the near abandonment of new antibiotic research against infectious diseases in the USA in early 1960s on the presumption that the world has discovered all necessary antibiotics, and that we have conquered all human infections.
Hence, should research continue in post cataract surgery endophthalmitis following the Endophthalmitis Vitrectomy Study? The fact remains that since the first publication of EVS in December 1995, there are 433 publications in peer reviewed English language journals (medline search) until December 2000 including nine in the IJO. These include unusual case reports (143), large comparative or non-comparative case series and reviews (156), and investigative and experimental treatments (125) (inclusive of microbiology, drug trials, and application of newer diagnostic technology). The Indian ophthalmologists and vision scientists working in India have published 25 research articles during this period- 9 in the IJO and 16 in other international peer reviewed journals. The Indian studies [8,9] have demonstrated that with larger prevalence of Gram negative and fungal infection, the microbial flora is different from the EVS. These eyes are presumably more severely infected, and are likely to benefit from vitrectomy and intravitreal antibiotics. The vitreous tap and intravitreal antibiotics only may prove inadequate. Accurate interpretation of the EVS data is important; an illogical application of the EVS recommendations will not benefit the patients. The Indian studies [8,9] have also demonstrated that while vancomycin is sensitive to most Gram positive cocci, ceftazidime is not necessarily the antibiotic of choice against all Gram negative bacteria. In a prospective randomized study it has also been demonstrated that intravitreal dexamethasone is useful in bacterial endophthalmitis.
Like many other infectious diseases, the best treatment of endophthalmitis is always prevention. This is possible when one respects and religiously practices all steps of asepsis and sterility. This issue of the journal has two articles on endophthalmitis- one on bacterial adherence to intraocular lenses (IOL), and the other on the preparation and strerilization of operating room and instruments. The study of Tyagi et al demands more careful handling of the IOLs so as to not carry infection into the eye. The communication of Ram et al provides important guidelines for prevention of cluster infection. These reports are timely reminders to exercise caution and implement all steps to prevent an unwanted postoperative infection.
The strategy in management of post cataract surgery endophthalmitis should be governed by the local infection patterns, the sensitivity of antibiotics, and the overall experience of the treating retinal surgeon. The EVS will obviously work as a guideline. There is no place for an empirical treatment of endophthalmitis that is, applicable uniformly to all patients in all parts of the world. RCTs are good examples of evidence-based medicine. Such evidenced- based medicine should be generated by periodic examination of large clinical series of patients. This helps in local modification of recommended treatment. However, microbial flora of infection, so also the sensitivity patterns are likely to change over period of time. The war between the microorganisms and the antibiotics will continue, and hence we have to be rather alert so as not to invite any surprises. There is no place for complacency. Yes: research, as applicable to treatment and prevention of endophthalmitis must continue.
| References|| |
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