Способы лечения послеоперационного эндофтальмита

    Topicality and purpose: This article reviews the modern treatment modalities of postoperative endophthalmitis.

    Inroduction

    Endophthalmitis is an inflammatory process which develops in the ocular cavities depends on the microbiologic growth comes from exogenous or endogenous sources. The main and most frequent reason of the exogenous endophthalmitis is bacterial contaminations of the eye during or after the intraocular surgery.

    Especially after cataract surgery, it is one of the most dreaded complication with an incidence between 0.5 to 0.04%. According to ESCRS endophthalmitis prophylaxis study the cultur positive endophthalmitis rate is 0.02 %. The main source of the endophthalmitis are contaminated solutions, instruments, surgeons hands, airborn bacteria and most probably ocular and face flora of the patients. If we see the endophthalmitis within 6 weeks of surgery we called acute postoperative endophthalmitis, after this period of time we classified as chronic endophthalmitis.

    Diagnosis

    Bacterial endophthalmitis are generally presented between 48 – 72 hours aftersurgery and include, ocular pain,diminished vision, lid edema, conjunctival chemosis with redness of the eye, cornael edema, flare and cells in the anterior chamber and pupillary area, hypopyon and loss of the red retinal reflex of the pupillary area. If we see the special signs and symptoms of the endophtahmitis, we have to evaluate the case carefully and make the diagnostic decision immediately;it is an ophthalmic urgency, patient must hospitalize and treatment algoritms must start promptly.

    Treatment algoritm of endophthalmitis:

    It is an emergency and should be managed energetically step by step as follows:

    1. Microbiologic diagnosis: As soon as the diagnosis of endophthalmitis is suspected, the first step is to obtain a vitreous sample in order to find the casual microorganisms. The samples have to be obtained by vitreous tap with 23 G needle via pars plana or vitreous biopsy using 23 or 25 G probe by way of transconjunctival trochars. Culture results are more successful with vitreous samples (46-69%) than anterior chamber samples (22-30 %). After direct examination, culture seeding should be performed. Gram positive bacteria are found mostly 85-94 % of the cases such as Staph. epidermidis(45-50%) , Streptococcus species(24-38% ) and Staph. aureus (7-11 %) .

    2. Intravitreal treatment with antibiotics: After diagnostic decision and obtaining of the vitreous samples, we have to inject antibiotics directly to vitreous cavity via pars plana in order to cover all the germs that can be responsible for the endophthalmitis. Two main antibiotic combinations are recommended for intravitreal injection:

    a. Vancomycin 1 mg / 0.1ml + ceftazidime 2 mg / 0.1ml

    b. Vancomycin 1 mg / 0.1ml + amikacine 0.4 mg / 0.1ml

    First preference is vancomycin and ceftazidime, because , vancomycinecovers mostly gram positives especially Staph. epidermidis,and ceftazidime (or amikacin) may be efficient to gram negatives. Of courseit is a brutal treatment and amikacin might be selected because of the synergistic effect of vancomycine togram positives but may cause macular infarction in up to 0.5% of the cases. If we prefer vancomycine – ceftazidime combination, we should use separate injectors for preventing the precipitation and become less bioavailable. Sometimes we add intravitreal steroidwith 400 microgram dexamethasone intravitreally to treatment for controlling the extreme inflammatory reaction and toxicity inside the vitreous cavity but we should avoid this treatment if there is any suspicion for fungal or viral ethiology. Streoid injections could be preferred to use after 48 hours of starting antibiotic injections. Actually if there is no clear regression of endophthalmitis after first antibiotic injections, we would repeat second doses in 48 to 72 hours especially in cases have some difficulties for planning vitrectomy surgery in short time.

    If we suspect about the fungal endophthalmitis, we should prefer amphotericin 5 microgram/0.1ml or 100 microgram/0.1ml voriconasole intravitreally.

    3. Topical antibiotics could be used in some cases with fortified forms but, in generally we do not recommended fortified forms because of the corneal epithelial toxicity and blurring because of edema. It is very important for the cases that might need surgery in advance in order to keep the corneal clarity. Therefore we advice just only routin antibiotic drops in those cases. They have to be combined with cycloplegics and low grade steroids for controlling the inflammatoy reaction as well.

    4. Systemic antibiotics: According to Endophthalmitis Vitrectomy Study, systemic antibiotics are not useful for treatment of endophthalmitis. Really there is no definitive study to prove that endophthalmitis cases better managed with than without systemic antibiotic therapy along with intravitreal antibiotics. In some cases, systemic antibiotics could be used especially high risk patients with diabetes or immun compromised cases or traumatic endophthalmitis with foreign body. The drug of choice for these case is quinolones because, they are fast bactericidal effect and have good bioavaliability, long half life and good penetration in the vitreous cavity. Because of the development of some resistance now in general, third generation of quinolones such as moxifloxacine or gatifloxacine are now being preferred. No special indication of systemic steroids in endophthalmitis cases.

    5. Vitrectomy surgery: According to endophthalmitis vitrectomy study, vitrectomy surgery has more effective in cases with only light perception. In this study immediate vitrectomy was adviced for the cases has visual acuity only light perception initially, if visual acuity was more than this, delayed vitrectomy was recommended especially in eyes had no respond to intravitreal antibiotic injections after 48 hours. But this study had been performed22 years ago and the vitrectomy technology and the surgical approach, technics and success rates and experience about the surgery is increased dramatically. Therefore nowadays vitrectomy surgery is used in cases with more than light perception and earlier indications for removing the infected vitreous, debris of bacteria and toxic and inflammatory materials as soon as possible to prevent toxic damage of retinal tissue. In most cases we would make decision about removing the intraocular lens and capsul during vitrectomy surgery.

    Because in time , toxic effects of infection is deteriorated the retinal tissue and we see very severe vasculitis , pale and necrotic retinal tissue that has necrotic tears or retinal detachment in the delayed surgery. Therefore in prompt surgery could save the retina before having toxic , necrotic and atrophic changes. In those cases , if we see some retinal teras or detachment or risk of severe complications we have to use silicone oil injection to keep the eye silent as long as possible. Because silicone oil might have some antibacterial effects and also keep the eye in global form with long term tamponade effect.It is allowed to be seen the retina in postoperative period and perhaps the vision might be recovered as far. If still we need some intravitreal antibiotics for the eyes even had been put silicone inside, we have to give 1/10 of regular doses.

    Conclusion

    The prophylactic protocol of ECRS study shows that if we use quinolone drops before and after surgery and 5% povidone iodine drops just before starting surgery and intracamaral cefuroxime 1 mgr/ 0.1ml at the end of surgery gives us the least endophthalmitis rates ever, such as 0.02% culture positivity.

    The diagnosis of endophthalmitis sometimes controversial in early period but, signs and symptoms must evaluate very carefully and make the decision as soon as possible. Then start to management algoritm step by step withobtaining the vitreous samples, intravitreal antibiotic injections and very tight control to evaluate if the case has a regression and make sure the indication of vitrectomy surgery. In last years surgical indications could be used earlier than before because of the advanced technics and technology in PPV surgery. The results are quite successfulanatomically as high as 90% recently.