Faculty Bibliography

PURPOSE: To determine whether a patient's age, gender, local or systemic risk factors affect the rate of preoperative bacterial contamination. METHODS: Consecutive 1,474 patients undergoing intraocular surgery were enrolled in this prospective masked study. Past medical history was noted and examinations were performed. The patients were divided into four groups: a control group (without local or systemic risk factors), those with local risk factors (chronic use of topical medications, contact lens wear, blepharitis, chronic eyelid or conjunctival inflammation), those with systemic risk factors (immunosuppression, diabetes, autoimmune conditions, and asthma), and those with both. Conjunctival cultures were obtained before surgery. RESULTS: Among the 1,474 patients, 914 bacteria were isolated from 214 (14.9%) patients. Advanced age was associated with a higher rate of positive conjunctival cultures (p<0.005). No statistical difference was found with regard to gender (p=0.7173). Among the 282 patients in the control group, 14 (5%) had a positive conjunctival culture. Compared to the control group, positive conjunctival cultures were found in 118 out of 503 patients (23.5%) with local risk factors (p<0.0001), 65 out of 545 patients (11.9%) with systemic risk factors (p=0.0019), and 22 out of 144 (15.3%) with both (p=0.0006). Two patients developed postoperative endophthalmitis (0.14%), one with both local risk and systemic factors and the other with a systemic risk factor. CONCLUSIONS: Patients with local or systemic risk factors or advanced age were found to have a higher rate of bacterial conjunctival contamination before intraocular surgery

Optic nerve glioma has been a topic of great interest and controversy, particularly with respect to its tendency to invade the optic chiasm. This case report demonstrates histologically verified optic nerve glioma in an otherwise healthy 5-year-old girl. MRI revealed sequential prechiasmal, chiasmal, and postchiasmal disease during the untreated course of 18 months. The authors also discuss the results obtained with a specific immunohistochemical technique, the mindbomb homolog 1 (MIB-1) labeling index, and speculate that this information, if known early in the course of disease, might influence early surgical decision-making

Bacterial infections of the eye highlight a dilemma that is central to all immune-privileged sites. On the one hand, immune privilege limits inflammation to prevent bystander destruction of normal tissue and loss of vision. On the other hand, bacterial infections require a robust inflammatory response for rapid clearance of the pathogen. We demonstrate that the retina handles this dilemma, in part, by activation of a protective heat shock protein. During Staphylococcus aureus-induced endophthalmitis, the small heat shock protein alphaB-crystallin is upregulated in the retina and prevents apoptosis during immune clearance of the bacteria. In the absence of alphaB-crystallin, mice display increased retinal apoptosis and retinal damage. We found that S. aureus produces a protease capable of cleaving alphaB-crystallin to a form that coincides with increased retinal apoptosis and tissue destruction. We conclude that alphaB-crystallin is important in protecting sensitive retinal tissue during destructive inflammation that occurs during bacterial endophthalmitis.

PURPOSE: To investigate whether intravitreal injection of dexamethasone in addition to antibiotics can minimize intraocular tissue injury caused by Staphylococcus aureus endophthalmitis. METHODS: Albino rabbits were infected with an intravitreal injection of 1000 colony-forming units of S. aureus. The rabbits were randomized to receive no treatment (control group; n = 2), intravitreal vancomycin and amikacin (n = 5), or a combination of intravitreal vancomycin, amikacin, and dexamethasone (n = 5) 20 hours following inoculation of bacteria. All rabbits except for the control group also received intravenous imipenem every 8 hours for 4 days. The eyes were evaluated by clinical examination, electroretinogram (ERG), and histologic studies. RESULTS: Eyes treated with intravitreal dexamethasone demonstrated less inflammation on clinical examination compared with eyes that received antibiotics alone. The ERG responses of eyes that received both intravitreal antibiotics and steroid were significantly better at 45 hours, 7 and 14 days following inoculation (P < 0.05) compared to eyes that received antibiotics alone. Histologic studies 14 days following infection demonstrated less tissue destruction for eyes treated with dexamethasone. CONCLUSION: Compared to intravitreal antibiotics alone, intravitreal corticosteroids may improve visual outcome of S. aureus endophthalmitis by reducing inflammation and preserving electrophysiologic retinal function

A 63-year-old woman presented subacutely with signs of orbital apex and cavernous sinus disease in the setting of widespread, untreated metastatic carcinoma of the uterus. MRI revealed a destructive lesion of the left sphenoid wing with compression of the orbital apex and with possible extension in the cavernous sinus. The underlying diagnosis was confirmed with repeat endometrial biopsy, revealing well-differentiated endometrial adenocarcinoma. Given the supporting clinical evidence for metastatic disease and the radiologic characteristics of the lesion, the decision was made to not perform a confirming orbital biopsy

PURPOSE: To compare the success of pars plana vitrectomy (PPV) versus scleral buckle (SB) in the management of uncomplicated pseudophakic retinal detachments (RDs). DESIGN: Meta-analysis of published studies from 1966 to 2004 regarding surgical treatment of pseudophakic RDs. PARTICIPANTS: Two thousand two hundred thirty eyes: 1579 operated by SB, 457 by PPV, and 194 by the combined method of PPV and SB. METHODS: We compared reattachment and functional success rates after 3 commonly practiced surgical interventions for pseudophakic RDs: PPV, SB, and the combined method. Twelve hundred thirty-two articles were retrieved from Medline and by cross-reference searches. Articles with sufficient data on preoperative evaluation, applied surgical technique, and anatomical and functional success rates were included in this analysis. Articles regarding complex pseudophakic RDs, treatment by laser or pneumatic retinopexy, studies with indistinguishable treatment outcomes from phakic and pseudophakic RDs, or reviews without original data were excluded. MAIN OUTCOME MEASURES: Anatomical success rates after initial surgical intervention and after reoperation(s) for primary failures, and best or final visual outcome at the end of follow-up. RESULTS: Of 1232 papers, 29 matched inclusion criteria. After controlling for variation between study characteristics, PPV and the combined method resulted in higher initial reattachment rates (odds ratio [OR], 1.69; 95% confidence interval [CI], 1.07-2.68, and OR, 3.54; 95% CI, 1.57-7.97, respectively) as compared with SB. The differences between the procedures persisted for final reattachment outcome despite reoperation for primary failures. Final visual outcome also was found to depend on the choice of primary surgical intervention. After controlling for differences in the study characteristics, the probability of visual improvement was higher after PPV (OR, 2.34; 95% CI, 1.58-3.46) or the combined method (OR, 11.52; 95% CI, 4.42-30.04) as compared with SB. CONCLUSIONS: A meta-analysis of published literature implies that PPV with or without SB is more likely to achieve a favorable anatomical and visual outcome than conventional SB alone in uncomplicated pseudophakic RDs. However, the inherent limitations of differing study protocols, quality of included studies, and publication bias in a pooled analysis should be recognized

PURPOSE: To determine the role of complement and Fas Ligand (FasL) in the host defense against Staphylococcus aureus endophthalmitis. METHODS: C3-/-, FasL defective gld, and C57/BL6 (wild-type [WT]) mice were infected intravitreally with 500 and 5000 CFU S. aureus, and the course of infection was followed by determining the intraocular bacteria counts, retinal function by ERG, and morphologic damage and inflammation by histopathology and flow cytometry. RESULTS: In WT eyes injected with 500 CFU, S. aureus grew to 1 x 10(7) CFU/mL by 24 hours, but was cleared by 96 hours. In the WT eyes injected with 5000 CFU, S. aureus grew to 2 x 10(9) CFU/mL by 72 hours, resulting in corneal perforation. C3-/- eyes injected with 500 CFU reached transiently higher levels than their WT counterparts (P < 0.001), but eventually followed a similar course. Bacterial counts in gld eyes infected with 500 CFU were similar to those in WT eyes infected with 5000 CFU. In WT and C3-/- eyes injected with 500 CFU, retinal function decreased only transiently and recovered to 66% in 72 hours. In WT eyes injected with 5000 CFU and gld eyes infected with 500 CFU, retinal function was completely lost by 24 hours. By 24 hours, WT and C3-/- eyes injected with 500 CFU were infiltrated with a similar number of granulocytes, but recruitment was significantly impaired in gld eyes (P < 0.005). Cell counts in WT and C3-/- eyes decreased thereafter without overt retinal disease. In eyes injected with 5000 CFU and gld eyes infected with 500 CFU, inflammatory cells completely filled the intraocular space by 48 hours. Retinal and uveal tissue was destroyed by that time. CONCLUSIONS: The tipping point for a good versus a bad outcome in this murine model of endophthalmitis lies between 500 and 5000 CFU S. aureus. This point is identical in animals deficient in complement activation, suggesting that complement does not play a significant role in the ocular defense against intraocular bacteria. In contrast, FasL was found to be critical for clearance, since animals deficient in FasL signaling were unable to control infection with 500 CFU

Gelatinase and serine protease were found to contribute in concert to pathogenesis in a rabbit model of endophthalmitis. However, a mutant defective in the fsr regulator was observed to be more attenuated than a mutant rendered defective in the expression of gelatinase and serine protease as the result of a polar transposon insertion into the former. This increased attenuation suggests that there are possible additional pleiotropic effects of the defect in fsr on expression of traits contributing to the pathogenesis of enterococcal infection.

BACKGROUND: Controversy still surrounds the intravenous (IV) treatment of endophthalmitis. The purpose of this study was to compare IV and intraocular (IO) treatment in experimental Staphylococcus aureus endophthalmitis: intravitreal injection of vancomycin and amikacin (VA/AN) in comparison with IV imipenem (IPM) and a combination of IV and IO (IV+IO) therapy. METHODS: The right eyes of 27 rabbits were injected with 25000 S. aureus. After 24 h, animals were either treated with IO VA/AN ( n=5; 1.0 mg/0.4 mg in 0.1 ml saline), or IV IPM ( n=9; 37 mg/kg body weight 3x daily), or IV+IO therapy ( n=7), or served as untreated controls ( n=6). Clinical appearance was evaluated daily and vitreous aspirates were obtained for bacterial culture 24 h and 6 days after therapy, when the eyes were enucleated for histopathologic examination. RESULTS: Eyes in the IO or IO+IV treatment group had a significantly better appearance clinically and histologically than did eyes in the IV or untreated control group. Eyes in the IO+IV group had a similar appearance to the IO-treated eyes. All aspirates from the IO and IO+IV groups were culture-negative 24 hours after therapy, whereas only five of nine in the IV-treated group were culture-negative. Aspirates from all treatment groups were culture-negative by day 6 after the initiation of therapy. Untreated control eyes were culture-positive at all times. CONCLUSION: IO therapy with VA/AN proved more effective in treating experimental S. aureus endophthalmitis than did IV therapy with IPM alone. IV+IO treatment was not superior to IO treatment alone

BACKGROUND: To compare the efficacy of intravenous (IV) imipenem (IPM) and a combination of IV ceftazidime (CAZ) and amikacin (AN) in the treatment of Staphylococcus aureus endophthalmitis in a rabbit model. METHODS: Right eyes of 60 albino rabbits were injected with 1000 colony-forming units of S. aureus intravitreally. After 24 h, treatment with either IV IPM (37.5 mg/kg) every 8 h ( n=18) or IV CAZ (50 mg/kg) and AN (10 mg/kg) every 8 hours ( n=18) was begun and continued until the animals were killed at the indicated timepoints; 24 control animals received no treatment. The concentration of bacteria in the vitreous from six animals per group was determined microbiologically on days 2, 3, and 5 after infection, and histologic examination was performed on all eyes. RESULTS: The number of eyes with positive cultures on day 5 was lower in the group that received IV IPM (2/6) compared with the IV CAZ/AN group (4/6) and the control group (6/6). For the culture-positive eyes, the bacterial concentrations were significantly lower for the IV IPM group compared with the IV CAZ/AN group on days 2 and 5 ( P<0.05 and P<0.0065, respectively), but not on day 3 ( P <0.8. Bacterial counts in both treatment groups were significantly lower than in the control group ( P<0.005). Eyes in all groups, however, showed severe intraocular inflammation. CONCLUSIONS: IV IPM is more effective than is IV CAZ/AN in reducing the number of bacteria in an animal model of S.aureus endophthalmitis