Daniel Briscoe

Changing Bacterial Isolates and Antibiotic Sensitivities of Purulent Dacryocystitis

Purpose: To examine the current spectrum of bacterial isolates in cases of chronic dacryocystitis and dacryoabcess and to determine their antibiotic sensitivities. Materials and methods: We carried out a prospective study in which 39 patients who presented to the outpatient clinic with chronic purulent dacryocystitis or acute dacryoabscess had cultures taken. All patients were antibiotic-free for at least one week prior to culturing. Results: The 39 positive cultures grew 41 bacterial isolates, as two patients grew two species of bacteria. Sixteen isolates (39%) were Gram positive and 25 (61%) were Gram negative. The most common isolates were Pseudomonas (22%), Staphylococcus aureus (13%), Enterobacter (10%), Citrobacter (10%), Streptococcus pneumoniae, Escherichia coli, and Enterococcus (7%). Uncommon Gram-negative bacteria were also cultured: Alcaligenes in 2 cases (5%) and one case of Stenotrophomonas maltophilia (2.5%). No anaerobic bacteria were isolated. Gram-negative isolates were sensitive to ceftazidime in 95%, ciprofloxacin in 86% and cefuroxime in 50%, with a sensitivity of less than 30% to cefalexin and ampicillin in those tested. All Pseudomonas isolates (100%) were sensitive to ceftazidime, 86% were sensitive to ciprofloxacin, while only 20% were sensitive to ampicillin and 14% to cefalexin. Alcaligenes was resistant to all antibiotics tested with the exception of ceftazidime. Conclusion: This study demonstrates a significant change in bacterial flora and antibiotic treatment requirements of purulent dacryocystitis from previously published data. A higher incidence of Gram-negative organisms, particularly Pseudomonas, with resistance to commonly used antibiotics was found. The emergence of rarer, highly resistant, Gram-negative microorganisms may also indicate a trend in lacrimal sac infections. These findings suggest that the antibiotic treatment protocol before and after lacrimal surgery should be reconsidered in this subgroup of patients.

Determining size and characteristics of metal intraocular foreign bodies using helical CT scan.

Purpose To carry out a pilot study comparing the size of various types of metallic intraocular foreign bodies as imaged on computed tomographic (CT) scan to their actual size, and to determine the features of different types of metals on CT scan. Methods Metallic foreign bodies of predetermined standardized sizes were prepared from iron, silver, copper, aluminium, and lead. The metallic pieces/shards were each inserted into the vitreous of a cows eye and helical CT scan (MX twin, Picker) was performed to image the intraocular foreign bodies, using soft tissue and bone window settings. Slice section thickness was 1.3 mm, with intervals of 0.6 mm. Milliampere per second was 265 and pitch 0.7. Results The size of all types of metals as measured on CT was larger than the actual size. Iron was enlarged by a factor of 2.29, silver 1.77, copper 1.26, and aluminum 1.17. All metals had features including central core, ring density, and artifacts which varied for each type of metal, giving each one a characteristic appearance Conclusions Helical CT scan could be useful in estimating the type and size of an intraocular metal foreign body made from iron, silver, copper, aluminium, or lead. (Eur J Ophthalmol 2009; 19: 861–5)

Treatment of Idiopathic Orbital Inflammatory Disease with Cyclosporine-A: A Case Presentation

We present a case of idiopathic orbital inflammatory disease that was responded favorably to low-dose cyclosporine-A.

Common orbital infections ~ State of the art ~ Part I

Infections of the orbit and periorbita are relatively frequent, and can cause significant local and systemic morbidity. Loss of vision occurs in more than 10% of patients, and systemic sequelae can include meningitis, intracranial abscess, and death. Numerous organisms infect the orbit, but the most common are bacteria. There are many methods through which orbital infections occur, with infection from the neighboring ethmoid sinuses the most likely cause for all age groups. Prompt management is essential in suspected orbital cellulitis, and involves urgent intravenous antibiotics, rehydration, and treatment of any co-existent underlying systemic disease, e.g., diabetes, renal failure. This review summarizes the common infectious processes of the orbit in both pediatric and adult groups. We review pathophysiology, symptoms, signs, and treatment for infectious orbital processes.