Intravenous cefazolin in penetrating eye injuries. Treatment of experimental posttraumatic endophthalmitis

Low rate of endophthalmitis in a large series of open globe injuries

PURPOSE

To determine the percentage of patients in whom endophthalmitis developed after open globe injury.

DESIGN

Retrospective, noncomparative, consecutive case series.

METHODS

Charts of all patients (675 in total) treated surgically for open globe injury at the Massachusetts Eye and Ear Infirmary (MEEI) between January 1, 2000 and July 31, 2007 were reviewed. Cases with at least 30 days of follow-up were included in statistical analyses (558 in total). A standardized treatment protocol was used in all cases. Intravenous vancomycin and ceftazidime were started on admission and were stopped after 48 hours. Patients were discharged on topical antibiotics, corticosteroids, and cycloplegia. Surgical repairs were performed by the chief of trauma, a full-time position rotating yearly, who is on call for all open globe trauma. Data collection variables included timing of injury and repair, mechanism of injury, details of surgical repair, and details of follow-up such as duration, presence of complications, and vision. A primary outcome measure of endophthalmitis and secondary outcome measure of risk factors for endophthalmitis were studied.

RESULTS

During 7.5 years, 675 open globe injuries were treated at MEEI. Of these, 558 had at least 30 days of follow-up (mean, 11 months) and were used in statistical analyses. The overall percentage of endophthalmitis was 0.9% (3 culture-positive cases and 2 culture-negative cases). Four of the 5 cases achieved final acuity of 20/80 or better. Risk factors for endophthalmitis included intraocular foreign body (P = .03; odds ratio, 7.52) and primary intraocular lens placement (P = .05).

CONCLUSIONS

A standardized protocol including surgical repair by a dedicated eye trauma service and 48 hours of intravenous antibiotics was associated with a posttraumatic endophthalmitis percentage of less than 1%.

Grepafloxacin Concentration in Ocular Tissues after Intravenous Infusion in Rabbits with Intraocular Inflammation

PURPOSE

To determine the penetration of grepafloxacin into ocular tissues during experimental ocular inflammation.

METHODS

10 albino and 10 pigmented rabbits underwent a continuous intravenous infusion of the drug 24 h after injecting Salmonella typhimurium toxin intravitreously, creating ocular inflammation. The animals were killed and grepafloxacin levels were determined in plasma and ocular tissues using high performance liquid chromatography.

RESULTS

Grepafloxacin levels achieved a steady-state plasma concentration of 1.5 microg/ml. The drug diffused more towards vascularized tissues (chorioretina and iris) in both albino and pigmented rabbits with a tissue/serum ratio higher than 1. Grepafloxacin showed more affinity to pigmented tissue, rising levels of 40,000-50,000 ng/g in the chorioretina and iris in pigmented animals. After inflammation, grepafloxacin intraocular penetration increased in albino animals with levels exceeding the minimum inhibitory concentration for the most common ocular pathogens.

CONCLUSION

Grepafloxacin intraocular penetration is higher in pigmented tissues. Ocular inflammation increases the drug penetration into the vitreous.

The Efficacy of Intravitreal Piperacillin/Tazobactam in Rabbits with Experimental Staphylococcus epidermidis Endophthalmitis: A Comparison with Vancomycin

BACKGROUND

To investigate the efficacy of intravitreal piperacillin/tazobactam in rabbit eyes with experimental S. epidermidis endophthalmitis and to compare the outcomes with intravitreal vancomycin application.

MATERIAL AND METHODS

Twenty-four New Zealand white albino rabbits were divided into three equal groups (n=8 in each), and the right eyes received 0.1-ml intravitreal injections of S. epidermidis suspension. The left eyes served as uninfected controls and were injected with 0.1 ml of saline solution. The right eyes of rabbits in group 1 were treated with intravitreal injection of 250 microg/0.1 ml piperacillin/tazobactam 24 h after intravitreal inoculation of S. epidermidis whereas group 2 eyes received intravitreal 1 mg/0.1 ml vancomycin. Group 3 eyes received no treatment and served as infected controls. Clinical examination of the eyes in each group was performed on the 1st, 3rd and 6th day after the inoculation of S. epidermidis. On the 6th day, 0.1-ml vitreous aspirates were obtained for microbiological analysis, and then the eyes were enucleated for histopathological evaluation.

RESULTS

There were no statistically significant differences in mean clinical scores between the groups on the first day after S. epidermidis inoculation (p>0.05). On the 6th day, the mean clinical score of group 3 was significantly higher (p<0.001), but the mean clinical scores of groups 1 and 2 were similar (p=0.812). The mean logarithmic value of colony-forming units per milliliter of groups 1, 2 and 3 were 0.6+/-1.3, 0.5+/-1.5 and 5.3+/-0.7, respectively. Mean histopathological scores of the groups were 8.3+/-0.9, 7.5+/-1.3 and 15.6+/-1.2, respectively. Group 3 eyes had significantly more colony-forming units per milliliter and a higher histopathological score (for each, p<0.001), and there were no statistically significant differences in microbiological and histopathological scores between groups 1 and 2 (for each, p>0.05).

CONCLUSION

Intravitreal application of 250 microg/0.1 ml piperacillin/tazobactam seems to be approximately equally effective with intravitreal 1 mg/0.1 vancomycin application in the treatment of experimental S. epidermidis endophthalmitis. Therefore, intravitreal piperacillin/tazobactam may be an alternative therapeutic option in the treatment of S. epidermidis endophthalmitis.

Aqueous and vitreous penetration of levofloxacin after oral administration

OBJECTIVE

To investigate the penetration of levofloxacin, an optical S-(-)isomer of ofloxacin, into the aqueous and vitreous humor after oral administration.

DESIGN

Randomized, clinical trial comparing tissue levels of levofloxacin after one or two doses 12 hours apart.

PARTICIPANTS

Forty-five patients undergoing initial vitrectomy between February 1997 and June 1997 at the UIC Eye Center.

METHODS

Aqueous, vitreous, and serum samples were obtained and later analyzed from 45 patients after oral administration of 1 500-mg tablet (group 1, 22 patients) or 2 500-mg tablets (group 2, 23 patients) 12 hours apart before surgery.

MAIN OUTCOME MEASURES

Aqueous, vitreous, and serum concentrations of levofloxacin (micrograms/milliliter).

RESULTS

Group 1 achieved mean aqueous, vitreous, and serum levels of 0.59 +/- 0.48 microg/ml, 0.32 +/- 0.34 microg/ml, and 4.34 +/- 3.59 microg/ml, respectively. Group 2 achieved mean aqueous, vitreous, and serum levels of 1.90 +/- 0.97 microg/ml, 2.39 +/- 0.70 microg/ml, and 8.02 +/- 3.14 microg/ml.

CONCLUSIONS

Mean inhibitory aqueous and vitreous MIC90 levels were achieved against a majority of ocular pathogens, including Staphylococcus aureus and Staphylococcus epidermidis, Streptococcus pneumoniae (vitreous), Bacillus cereus (vitreous), Haemophilus influenzae, Moraxella catarrhalis, and most gram-negative aerobic organisms except Pseudomonas aeruginosa after two doses given 12 hours apart. Mean MIC90 levels were obtained in the vitreous for a majority of pathogens responsible for traumatic, postoperative, or bleb-related endophthalmitis.

Endophthalmitis

Endophthalmitis is an inflammatory reaction of intraocular fluids or tissues. Infectious endophthalmitis is one of the most serious complications of ophthalmic surgery. Occasionally, infectious endophthalmitis is the presenting feature of an underlying systemic infection. Successful management of infectious endophthalmitis depends on timely diagnosis and institution of appropriate therapy. Recognition of the different clinical settings in which endophthalmitis occurs and awareness of the highly variable presentation it may have facilitate timely diagnosis. Biopsy of intraocular fluid/tissue is the only method that permits reliable diagnosis and treatment. The different presenting clinical settings, a rational approach to diagnosis (i.e., when, what, and how to biopsy), and the treatment of infectious endophthalmitis are reviewed.

Endophthalmitis following penetrating eye injuries

Postinjury endophthalmitis is the eye infection with the worst prognosis. A retrospective 9-year study was made of penetrating eye injuries, with an analysis of the incidence of infection and its relation to the type of wound and the presence of intraocular foreign bodies. There were 403 cases of penetrating eye injury; of these, 233 affected the cornea and 170 involved the posterior pole. Intraocular foreign bodies were present in 40 cases. Endophthalmitis developed in 4.2% of cases (17/403), and was more common in patients with posterior pole involvement (7%) than in purely corneal trauma (2.1%) (p = 0.03, Chi-square). Infection was in turn more frequent in the presence of intraocular foreign bodies (15%) (p = 0.17, Chi-square). Staphylococcus epidermidis was the most common cause (23.4%), while in three cases (17.6%) mixed infection was detected. The visual results were evisceration or non-perception of light in 82.3% of cases.

The effect of trauma on the ocular penetration of intravenous ciprofloxacin

PURPOSE

To study the intraocular pharmacokinetics of intravenously administered ciprofloxacin following eye trauma.

METHODS

Twenty-three New Zealand albino rabbits and 12 Yorkshire pigs each received a surgically induced scleral injury to the right eye. Following repair, each rabbit received a single 30-mg intravenous infusion of ciprofloxacin. Each pig received either two 200-mg doses or two 400-mg doses of intravenous ciprofloxacin given 12 hours apart. Vitreous and serum samples were harvested at 0.5, 1, 4, 6, and 12 hours after antibiotic administration in rabbits and 1 hour after the second dose in pigs. Bioassays for ciprofloxacin were performed on each sample, and results were statistically compared by t test. The untraumatized left eye in each animal served as a control.

RESULTS

The mean vitreous concentration of ciprofloxacin in traumatized rabbit eyes was 0.37 microgram/ml. This level was sustained above levels in control eyes (0.18 microgram/ml) for at least 4 hours following antibiotic administration. In control eyes, intravitreal levels peaked at 1 hour. Mean vitreous concentrations +/- SD in traumatized pig eyes were 0.091 +/- 0.017 microgram/ml in swine that had received 200-mg doses of ciprofloxacin vs 0.312 +/- 0.153 microgram/ml in swine that had received 400-mg doses (P = .02). Mean vitreous concentrations of ciprofloxacin in control eyes were not affected by increasing dosage.

CONCLUSION

In both animal models, experimental surgical trauma increased intravitreal ciprofloxacin delivery. In addition, systemically administered ciprofloxacin achieved intravitreous levels exceeding minimum inhibitory concentrations for common ocular pathogens, suggesting a role for ciprofloxacin in the prophylaxis of posttraumatic endophthalmitis.