Preoperatively administered flomoxef sodium concentration in aqueous humor

PURPOSE: We intravenously administered flomoxef sodium (FMOX) 0.5-3.5 hours before cataract surgery and measured the concentration of the agent in the aqueous humor to investigate its penetration into the aqueous humor and its efficacy in the prevention of postoperative endophthalmitis. METHODS: 56 patients who underwent cataract surgery were enrolled in this study. They received 1 g FMOX via a 20-minute intravenous drip beginning 0.5-3.5 hours before the operation. Aqueous humor was aspirated from the anterior chamber and assayed for FMOX concentration using high-performance liquid chromatography. RESULTS: The mean intraoperative FMOX concentrations in the patients' aqueous humor were 0.79 +/- 0.24 microg/ml (administered 3.5 hours before surgery)--1.47 0.79 microg/ml (administered 1.5 hours before surgery). These concentrations administered 0.5-3.0 hours before surgery sufficiently exceeded the minimum inhibitory concentration (MIC) 90 values against Staphylococcus epidermidis, Staphylococcus aureus and Propionibacterium acnes, but did not achieve the MIC90 values against Enterococcus faecalis and Pseudomonas aeruginosa. CONCLUSIONS: The FMOX concentrations in the aqueous humor sampling were adequate to kill bacteria in vitro. This drug may be efficacious in the prevention of postoperative endophthalmitis in patients undergoing cataract surgery.     

Flomoxef sodium and levofloxacin concentrations in aqueous humor

AIMS: We intravenously administered flomoxef sodium (FMOX) 120 minutes before cataract surgery, topically administered levofloxacin (LVFX) into the eyes four times at 30-minute intervals before surgery, and measured the aqueous humor concentrations of these agents to investigate their penetration into the aqueous humor and their efficacy in the prevention of postoperative endophthalmitis. METHODS: Sixty-eight patients who underwent cataract surgery at the Department of Ophthalmology, Yokohama City University School of Medicine, or its affiliate, Kanazawa Hospital, Yokohama, were enrolled in this study. They received one or both of the following: 1.0 g FMOX via a 20-minute intravenous drip and LVFX ophthalmic solution applied four times at 30-minute intervals, both beginning two hours before the operation. Aqueous humor was aspirated from the anterior chamber and assayed for FMOX and LVFX concentrations using high-performance liquid chromatography (HPLC). RESULTS: The mean intraoperative FMOX and LVFX concentrations in the patients' aqueous humor were 1.21 +/- 0.63 microg/ml and 0.69 +/- 0.47 microg/ml, respectively. These concentrations sufficiently exceeded the MIC90 values against Staphylococcus epidermidis, S. aureus, and Propionibacterium acnes. CONCLUSIONS: The FMOX and LVFX concentrations in the aqueous humor sampling were adequate to kill bacteria in vitro. These drugs may have efficacy in the prevention of postoperative endophthalmitis in patients undergoing cataract surgery.     

Comparison of 2 moxifloxacin regimens for preoperative prophylaxis: prospective randomized triple-masked trial. Part 1: aqueous concentration of moxifloxacin

PURPOSE: To evaluate the aqueous concentration of moxifloxacin following 2 dosing regimens of topically administered moxifloxacin hydrochloride ophthalmic solution 0.5% (Vigamox). SETTING: Iladevi Cataract & IOL Research Centre, Ahmedabad, India. METHODS: In this prospective randomized triple-masked clinical trial, 156 patients having cataract surgery were randomly assigned to 1 of 2 regimens of preoperative prophylaxis. In Group A (n = 76), Vigamox was instilled 4 times a day 1 day before surgery plus 1 drop 2 hours before surgery (total of 5 drops). In Group B (n = 76), Vigamox was first instilled 2 hours before surgery and then every 15 minutes for 1 hour (total of 5 drops). In both groups, aqueous samples (0.1 mL) were collected within 2 hours of the first instillation on the day of surgery and stored at -80 degrees C. The antibiotic concentration in all aqueous aspirates was determined using high-performance liquid chromatography. Data were analyzed using the Kolmogorov-Smirnov t test; 95% confidence intervals (CIs) were calculated. RESULTS: The mean aqueous humor concentration of moxifloxacin was 1.58 microg/mL +/- 0.80 (SD) in Group A and 2.05 +/- 0.72 microg/mL in Group B (P<.0001; 95% CI, -0.72 to -0.22). CONCLUSIONS: Both dosing regimens produced substantially higher aqueous concentrations than the known minimum inhibitory concentration for Staphylococcus epidermidis. Topical moxifloxacin administered 2 hours before surgery achieved significantly higher aqueous concentrations than topical moxifloxacin administered 1 day before surgery with 1 drop given on the day of surgery.     

Aqueous humor levels of topically applied levofloxacin in human eyes

PURPOSE: To evaluate transcorneal penetration of topically applied 0.5% levofloxacin into the aqueous humor in human eyes. METHODS: Twenty cataract patients (14 females, 6 males) received 3 drops of 0.5% levofloxacin at 15 min intervals from 90 minutes before the surgery. At the beginning of the cataract surgery, 50 microL of aqueous humor was aspirated from the anterior chamber and stored at -80 degrees C until analysis. The drug concentration of the samples was analyzed using high-performance liquid chromatography. RESULTS: A mean aqueous humor level of levofloxacin was 1.00 +/- 0.48 microg/mL (mean +/- standard deviation, n = 20), ranging from 0.30 microg/mL to 2.32 microg/mL. CONCLUSIONS: The mean concentration of levofloxacin in the aqueous humor was higher than the MIC(90) values against some common pathogens of postoperative endophthalmitis, although a great degree of interpatient variability was present.     

Aqueous humor levels of topically applied levofloxacin, norfloxacin, and lomefloxacin in the same human eyes

PURPOSE: To assess the relative penetration of topical eyedrops of 3 fluoroquinolones into the aqueous humor in human eyes. SETTING: Department of Ophthalmology, Sano-Kosei Hospital, Sano, Japan. METHODS: Fifty-nine cataract patients (36 women, 23 men) received 3 drops each of levofloxacin 0.5%, norfloxacin 0.3%, and lomefloxacin 0.3% in the same eye at 15-minute intervals beginning 90 minutes before cataract surgery. At the beginning of surgery, 50 microL of aqueous humor was aspirated from the anterior chamber and stored at -80 degrees C until analyzed. The drug concentrations in the samples were analyzed using high-performance liquid chromatography. RESULTS: Five patients were excluded from the study because their sample volumes were insufficient. Norfloxacin was detected in 3 patients; the mean aqueous humor level was 0.10 microg/mL +/- 0.02 (SD). Levofloxacin was detected in all cases; the mean aqueous humor level was 0.60 +/- 0.28 microg/mL (n = 54). Lomefloxacin was not detected in 10 patients; the mean aqueous humor level was 0.23 +/- 0.11 microg/mL (n = 44). CONCLUSION: Topically applied levofloxacin had better penetration into the aqueous humor than lomefloxacin and norfloxacin.     

Aqueous humor penetration of gatifloxacin and moxifloxacin eyedrops given in different concentrations in a wick before cataract surgery

PURPOSE: To determine whether the penetration into the aqueous humor of gatifloxacin (Zymar) and moxifloxacin (Vigamox) eyedrops was affected by altering their concentrations in the dilating mixture in which the wick used to dilate the pupil before cataract surgery was soaked. SETTING: Pasqua Hospital, Regina, Saskatchewan, Canada. METHODS: This prospective randomized open-label study comprised 65 women and 35 men who were divided into 2 main groups. One group received 1 mL of the antibiotic in the dilating mixture and the other, 2 mL. Each group was divided into 2 subgroups, 1 for gatifloxacin and 1 for moxifloxacin. At the beginning of surgery, 0.1 mL of aqueous humor was aspirated, frozen, and couriered to the provincial laboratory for analysis by high-performance liquid chromatography. RESULTS: In the first group, the mean concentration of gatifloxacin in the aqueous humor was 0.30 microg/mL +/- 0.21 (SD) and of moxifloxacin, 0.97 +/- 0.63 microg/mL. When the volume of the antibiotic in the dilating mixture was doubled, the mean concentration increased to 0.34 +/- 0.25 microg/mL and 1.37 +/- 0.79 microg/mL, respectively. Only the increased penetration of moxifloxacin was statistically significant. CONCLUSIONS: Moxifloxacin penetrated the aqueous humor better than gatifloxacin when given in a wick soaked in the dilating mixture before cataract surgery. Only the penetration of moxifloxacin increased significantly when the volume of the antibiotic in the dilating mixture was doubled. In both groups, only moxifloxacin reached and exceeded the minimum inhibitory concentration levels for the most common ocular pathogens causing endophthalmitis.     

Hepatocyte growth factor is increased in the aqueous humor of glaucomatous eyes.

PURPOSE: To assess the concentrations of hepatocyte growth factor (HGF) in the aqueous humor of eyes with glaucoma compared with control eyes with cataract only. METHODS: Concentrations of HGF were measured in aqueous humor aspirates taken during anterior segment surgery from 84 patients, of whom 72 had glaucoma (38 cases of primary open-angle glaucoma, 17 angle-closure glaucoma, and 17 exfoliative glaucoma) and 12 had cataract only, using a sandwich enzyme-linked immunosorbent assay kit. RESULTS: Hepatocyte growth factor was detected in all samples. The concentration in eyes with cataract only was 563.3 +/- 178.8 pg/mL (mean +/- standard deviation), which was significantly lower than that in eyes with glaucoma (967.1 +/- 514.7 pg/mL, P < 0.01). Eyes with exfoliative glaucoma had significantly higher HGF concentrations (1,425.5 +/- 586.7 pg/mL) than did eyes with primary open-angle glaucoma (855.0 +/- 341.5 pg/mL) and angle-closure glaucoma (759.4 +/- 511.4 pg/mL) (P < 0.01). There was no effect of age, sex, or history of medical, laser, or surgical treatment on the aqueous humor HGF concentration (P > 0.05). Aqueous humor and plasma HGF concentrations were measured and compared in 28 patients. The aqueous humor HGF concentration (908 +/- 586.2 pg/mL) was significantly higher (P < 0.01) than the plasma concentration (521.3 +/- 183.1 pg/mL). No significant correlation could be found between aqueous humor and plasma HGF concentrations. CONCLUSIONS: The relatively high concentration of HGF in human aqueous humor suggests that HGF may play an important role in ocular physiology and disease. The higher concentration in patients with glaucoma may indicate a response to injury.     

Ocular penetration of cefepime following systemic administration in humans

OBJECTIVE: To investigate the penetration of cefepime (a fourth generation cephalosporin) into the aqueous humor after single-dose intravenous administration in humans. PATIENTS AND METHODS: Before receiving cataract surgery, 30 patients received randomly 1 g (group 1, 15 patients) and 2 g (group 2, 15 patients) single intravenous injection of cefepime before surgery. Samples of aqueous humor and serum were obtained at 0.5, 1, 2, 4, and 12 hours after injection. Three patients were sampled each time for 1 g and 2 g of cefepime. Samples were assayed for cefepime concentrations with high performance liquid chromatography (HPLC). RESULTS: All the patients had detectable cefepime in their aqueous humor and serum measurable by HPLC. A mean peak aqueous humor level was 5.16 +/- 0.88 microg/mL in group 1 and 5.87 +/- 1.64 microg/mL in group 2 at 0.5 hour after injection. The mean level of cefepime in aqueous humor decreased after 0.5-hour measurements in both groups and was measured as 0.82 +/- 0.21 microg/mL in group 1 and 2.04 +/- 0.30 microg/mL in group 2 at 12 hours after injection. CONCLUSION: Aqueous humor levels of cefepime after single IV injection were above the minimum inhibitory concentration (MIC90) for most ocular pathogens, but the duration of exposure to an antibiotic was not sufficient for therapeutic effect.     

The effect of cataract surgery on ocular levels of topical moxifloxacin

PURPOSE: To investigate the effect of cataract surgery on the concentration of moxifloxacin in aqueous and vitreous humor after topical application. DESIGN: Prospective laboratory intervention using a rabbit model. METHODS: Following topical administration of 0.5% moxifloxacin, 60 minutes before surgery and immediately post cataract surgery, aqueous and vitreous humor were sampled at 30, 60, and 120 minutes postsurgery. Moxifloxacin concentrations were determined by high-pressure liquid chromatography (HPLC). Mean tissue concentrations obtained in surgical eyes were compared with concentrations obtained in nonsurgical eyes. The potential effectiveness of moxifloxacin in providing prophylaxis against intracameral bacterial inoculation was investigated by comparing antibiotic concentrations to minimum inhibitory concentration (median MIC90) values for Staphylococcus aureus and Staphylococcus epidermidis. RESULTS: In surgical eyes, mean moxifloxacin concentrations in aqueous were 13.9, 16.2, and 12.2 microg/ml versus 25.3, 32.6, and 15.7 microg/ml in nonoperated eyes at 30, 60, and 120 minutes, respectively. No statistically significant differences were found between surgical and nonsurgical eyes. In surgical eyes, mean moxifloxacin concentrations in vitreous were 66.8, 66.6, and 400.2 ng/ml versus 43.1, 199.8, and 54.4 ng/ml in nonoperated eyes at 30, 60, and 120 minutes, respectively. These differences were not statistically significant. CONCLUSIONS: There were no statistically significant differences in the penetration of topical moxifloxacin in eyes undergoing cataract surgery compared with unoperated eyes. A multiple-drop schedule of moxifloxacin produced aqueous concentrations that were well above the MICs of even resistant strains of the most common organisms implicated in postcataract surgery endophthalmitis.     

Penetration of topically applied ciprofloxacin and ofloxacin into the aqueous humor and vitreous

PURPOSE: To determine the intraocular penetration of topical drops of 2 antibiotics, ciprofloxacin 0.3% and ofloxacin 0.3%, into the aqueous humor and vitreous and to relate these levels to the miminum inhibitory concentration (MIC(90)) for organisms associated with ocular bacterial infections. SETTING: Department of Ophthalmology, Ankara Hospital, and Department of Pharmacology, Faculty of Medicine, Hacettepe University, Ankara, Turkey. METHODS: This prospective randomized clinical trial comprised 18 patients having cataract surgery, all with an intact corneal epithelium. The patients were randomly assigned to receive topical ciprofloxacin 0.3% (n = 10) or topical ofloxacin 0.3% (n = 8) 1 drop every 15 minutes 5 times and every 30 minutes 3 times before surgery. Aqueous and vitreous samples (if vitreous loss occurred during the cataract surgery) were collected 30 minutes after the administration of the last dose. Drug concentrations were determined by high-performance liquid chromatography (HPLC) fluorescence. RESULTS: All patients had detectable drug concentrations in the aqueous humor and vitreous measurable by HPLC. The mean aqueous humor concentration of ciprofloxacin was 1.13 microg/mL +/- 1.90 (SD) and the mean vitreous concentration, 0.23 +/- 0.06 microg/mL. Topical administration of ciprofloxacin yielded 4.9 times more drug concentration in the anterior chamber than in the vitreous. The mean aqueous concentration of ofloxacin was 2.06 +/- 1.06 microg/mL and the mean vitreous concentration, 0.46 +/- 0.10 microg/mL. Topical administration of ofloxacin yielded 4.7 times more drug concentration in the anterior chamber than in the vitreous. Aqueous humor concentrations of ofloxacin and ciprofloxacin were not statistically significantly different (P =.353). Intravitreal concentrations of ofloxacin were statistically significantly higher than those of ciprofloxacin (P =.001). CONCLUSIONS: Topical ofloxacin 0.3% penetrated better than topical ciprofloxacin 0.3% into the anterior chamber and vitreous in noninflamed eyes. Both drugs were above the MIC(90) for most ocular pathogens in the anterior chamber. The mean concentration in the vitreous of topically applied ofloxacin 0.3% was statistically significantly higher than that of ciprofloxacin 0.3%, but it was not sufficiently above the MIC(90) for most ocular pathogens in terms of empirical endopthalmitis therapy.     

Penetration of betaxolol HCL ionic suspension 0.25% and betaxolol HCL solution 0.50% into the aqueous humor

PURPOSE: To determine the intraocular penetration of topical drops of betaxolol HCl 0.25% suspension and betaxolol HCl 0.50% solution into the aqueous humor. METHODS: Fifteen patients were randomly assigned to receive topical betaxolol HCl 0.25% suspension (n=7) or topical betaxolol HCl 0.50% solution (n=8) the day before cataract surgery. Aqueous samples were collected 2 hours after the administration of the morning dose during cataract surgery. Drug concentrations were determined by high-performance liquid chromatography with fluorescence detection. RESULTS: The mean aqueous humor concentration of topical betaxolol HCl 0.25% suspension was 275.1+/-168.8 micro g/mL (range 570-70 micro g/mL) and the mean aqueous humor concentration of topical betaxolol HCl 0.50% solution was 195.4+/-102.4 micro g/mL (range 334-50 micro g/mL) (p=0.281). CONCLUSIONS: The mean aqueous humor concentration of betaxolol 0.25% suspension was higher than betaxolol 0.50% solution; however, the difference was not statistically significant. With twofold reduced concentration and similar anterior chamber penetration, betaxolol 0.25% suspension could be first choice for Beta 1 selective blocker therapy when considered for patients with glaucoma.     

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.     

Vascular endothelial growth factor is increased in aqueous humor of glaucomatous eyes

PURPOSE: To assess the concentrations of vascular endothelial growth factor (VEGF) in aqueous humor in eyes with and without glaucoma. METHODS: Concentrations of VEGF were measured using a sandwich ELISA kit in aqueous humor aspirates taken during anterior segment surgery from 87 patients, of whom 54 had glaucoma (27 primary open-angle glaucoma, 8 angle-closure glaucoma, 16 exfoliative glaucoma) and 33 had cataract only. RESULTS: Vascular endothelial growth factor was detected in all samples. The concentration in eyes with cataract only without glaucoma was 102.4 +/- 29.7 pg/mL (mean +/- SD), which was significantly lower than that from eyes with glaucoma (146.7 +/- 51.8 pg/mL). There were no significant differences between primary open-angle glaucoma (140.4 +/- 51.0 pg/mL), angle-closure glaucoma (142.8 +/- 40.2 pg/mL), and exfoliative glaucoma (158.6 +/- 58.9 pg/mL). An unusually high VEGF concentration was detected in one eye with neovascular glaucoma (759 pg/mL) and two eyes with uveitic glaucoma (322 pg/mL). No effect of age, gender, or previous history of medical, laser, or surgical treatment of the aqueous humor VEGF concentration could be detected ( > 0.05). Aqueous humor and plasma VEGF concentrations were measured and compared in 46 patients. The aqueous humor VEGF concentration (144.2 +/- 107.9 pg/mL) was significantly higher ( < 0.01) than the plasma concentration (79.2 +/- 46.1 pg/mL). No significant correlation was found between aqueous humor and plasma VEGF concentrations. CONCLUSION: Aqueous VEGF concentration is increased in eyes with glaucoma.     

Penetration of imipenem into human aqueous and vitreous humor

Twenty-five patients about to undergo cataract surgery and ten patients about to undergo vitrectomy received a 1-g intravenous dose of imipenem before surgery. Specimens of aqueous or vitreous humor were then obtained and assayed for antibiotic content with a microbiologic disk agar technique. A mean peak aqueous humor level of 2.99 micrograms/ml was found at approximately two hours after administration, and a mean vitreous level of 2.53 micrograms/ml was found from two hours to three hours 15 minutes after administration. These concentrations were well above the minimum inhibitory concentration of imipenem for 90% (MIC90) of Staphylococcus epidermidis, S. aureus, and the Enterobacteriaceae commonly involved in bacterial endophthalmitis.     

Aqueous humor erythropoietin levels in patients with primary open-angle glaucoma

PURPOSE: To evaluate the levels of erythropoietin (EPO) in the aqueous humor in eyes with primary open-angle glaucoma (POAG) and without glaucoma. METHODS: Levels of EPO were measured using a sandwich enzyme-linked immunosorbent assay kit in aqueous humor aspirates taken during anterior segment surgery from 45 patients, of whom 20 had POAG and 25 had senile cataract only. RESULTS: The mean aqueous humor EPO concentration in eyes with POAG (10.91+/-4.32 mU/mL) was significantly higher than that from eyes with cataract (8.24+/-1.77 mU/mL, P=0.008). There was no significant difference between the serum EPO concentrations of POAG (26.46+/-10.36 mU/mL) and the control group (24.50+/-7.59 mU/mL, P=0.468). There was no correlation (P=0.165) between the EPO aqueous humor concentration and the EPO serum concentration while there was no correlation between the EPO aqueous humor concentration and the EPO serum concentration in the control group (P=0.819). CONCLUSIONS: The aqueous humor EPO level is increased in eyes with POAG.     

Concentration of hyaluronic acid in primary open-angle glaucoma aqueous humor

We compared the concentration of hyaluronic acid in the aqueous humor of primary open-angle glaucoma (POAG) patients and non-glaucomatous patients. Aqueous humor samples were obtained from 22 patients just before trabeculectomy for clinically uncontrolled POAG (POAG group). Aqueous humor (0.1 mL) was aspirated by inserting a 26-gauge needle into the anterior chamber. The same procedure was performed for 22 non-glaucomatous patients just before cataract surgery (control group). Immediately after collection, the aqueous humor was stored at -20 degrees C. The concentration of hyaluronic acid was determined by a sensitive, noncompetitive and nonisotopic fluoroassay. The median (range) concentrations of hyaluronic acid of the POAG and control groups were 298.4 microg L(-1) (99.0-743.7 microg L(-1)) and 545.1 microg L(-1) (145.0-2366.0 microg L(-1)), respectively. The difference in concentrations of hyaluronic acid between the groups was statistically significant (P<0.001). In conclusion, the concentration of hyaluronic acid in the aqueous humor in POAG patients is lower than in non-glaucomatous patients. Further studies are necessary to determine the role of hyaluronic acid in the pathophysiology of POAG.     

Human aqueous humor levels of oral ciprofloxacin, levofloxacin, and moxifloxacin

PURPOSE: To evaluate the penetration of ciprofloxacin, levofloxacin, and moxifloxacin into the aqueous humor after oral administration. SETTING: Alcorcon Hospital, Madrid, Spain. METHODS: Forty-two patients having cataract surgery were randomly divided into 3 groups the day before surgery. The first group received 2 oral 500 mg doses of ciprofloxacin at 12-hour intervals. The second group received a single oral 500 mg dose of levofloxacin. The third group received a single oral 400 mg dose of moxifloxacin. At the time of surgery, 0.1 mL aqueous fluid was aspirated from the anterior chamber just before the operation and immediately stored at -80 degrees C. Drug concentrations were measured using a biological assay. RESULTS: The mean aqueous level of ciprofloxacin was 0.50 microg/mL +/- 0.25 (SD); of levofloxacin, 1.50 +/- 0.50 microg/mL; and of moxifloxacin, 2.33 +/- 0.85 microg/mL. The mean aqueous levels of levofloxacin and moxifloxacin were above the 90% minimum inhibitory concentration for most of the common microorganisms that cause endophthalmitis. CONCLUSIONS: Therapeutic concentrations of fluoroquinolones, mainly levofloxacin and moxifloxacin, were reached with oral administration. These antibiotics may be effective for prophylaxis and adjuvant therapy of bacterial endophthalmitis.     

Increased levels of transforming growth factor-betal and -beta2 in the aqueous humor of patients with neovascular glaucoma.

BACKGROUND AND OBJECTIVE: To measure the concentrations of transforming growth factor-betal and beta2 (TGF-beta1 and TGF-beta2) in the aqueous humor of patients with neovascular glaucoma (NVG). PATIENTS AND METHODS: Patients were divided into four groups: NVG secondary to central retinal vein occlusion (group 1), NVG secondary to proliferative diabetic retinopathy (group 2), central retinal vein occlusion without rubeosis (group 3), and senile cataract (group 4). The total TGF-beta 1 and TGF-beta2 concentrations in the aqueous humor of the four groups were measured by enzyme linked immunosorbent assay. RESULTS: The mean concentrations of total TGF-betal were 600.7 +/-436.7 microg/mL in group 1, 802.0 +/-359.5 pg/mL in group 2, and undetectable in groups 3 and group 4 (P < .05). The mean concentrations of total TGF-beta2 were 6,307.9+/- 2,206.2 microg/mL in group 1, 5,908.0+/-2,033.2 microg/mL in group 2, 899.7+/- 425.6 microg/mL in group 3, and 385.7 +/-89.9 microg/mL in group 4. The total TGF-betal and TGF-beta2 concentrations in groups 1 and 2 were significantly higher than those in groups 3 and 4, whereas the total TGF-beta2 concentration in group 3 was significantly higher than that in group 4 (P < .05). There was no significant difference in the TGF-betal or TGF-beta2 concentrations between groups 1 and 2 (P> .05). CONCLUSIONS: The abnormally high concentrations of TGF-betal and TGF-beta2 in the aqueous humor of patients with NVG may explain some aspects of the pathogenesis of NVG and the high failure rate of filtering operations in NVG.     

Decreased levels of pigment epithelium-derived factor in eyes with neuroretinal dystrophic diseases

PURPOSE: To determine the concentration of pigment epithelium-derived factor (PEDF) in the aqueous humor of eyes with neuroretinal dystrophy. DESIGN: Observational case series. METHODS: Aqueous humor was obtained from patients during cataract surgery, and the PEDF concentration in the aqueous humor was measured by enzyme-linked immunosorbent assay. The primary diagnosis was cataract in 162 eyes; of these there were five eyes with retinitis pigmentosa, nine eyes with advanced glaucoma, and 148 eyes with cataract alone. RESULTS: The mean levels of PEDF in eyes with retinitis pigmentosa (0.24 +/- 0.04 microg/ml, mean +/- SE, P =.0004) and advanced glaucoma (0.46 +/- 0.08 microg/ml, P =.003) were significantly lower than that in eyes with cataract alone (0.86 +/- 0.04 microg/ml). CONCLUSION: The lower levels of PEDF in eyes with neuroretinal dystrophy may be related to the loss of the retinal ganglion cells or retinal pigment epithelium cells that synthesize PEDF.     

Aqueous and vitreous penetration of linezolid (Zyvox) after oral administration

OBJECTIVE: To investigate the penetration of linezolid, a synthetic oxazolidinone antibiotic, into the aqueous and vitreous humor after oral administration. DESIGN: Noncomparative interventional, prospective case series study, randomized into group 1 (dose, one 600-mg tablet) or group 2 (2 doses of 600 mg given 12 hours apart). PARTICIPANTS: Patients undergoing pars plana vitrectomy between March 2001 and August 2002 at the University of Illinois at Chicago Eye Center who had not had prior vitrectomy surgery. METHODS: Aqueous, vitreous, and plasma samples were obtained and analyzed from 29 patients after oral administration of 1 dose (group 1A, 13 patients [13 eyes] sampled less than 2 hours after administration; group 1B, 9 patients [9 eyes] sampled more than 2 hours after administration) or 2 doses 12 hours apart (group 2, 7 patients [7 eyes]) before surgery. MAIN OUTCOME MEASURES: Aqueous, vitreous, and plasma concentrations of linezolid (micrograms per milliliter). RESULTS: Group 1A achieved mean aqueous, vitreous, and plasma levels of 0.77+/-0.6 microg/mL, 0.3+/-0.3 microg/mL, and 5.0+/-3.3 microg/mL, respectively. Group 1B achieved mean aqueous, vitreous, and plasma levels of 3.8+/-1.2 microg/mL, 2.3+/-1.4 microg/mL, and 7.6+/-2.7 microg/mL, respectively. Group 2 achieved mean aqueous, vitreous, and plasma levels of 6.6+/-2.7 microg/mL, 5.7+/-2.7 microg/mL, and 10.3+/-4.1 microg/mL, respectively. CONCLUSIONS: Mean inhibitory aqueous and vitreous minimum inhibitory concentrations for 90% of isolates (MIC(90)) were achieved against all gram-positive bacteria, including vancomycin-resistant enterococcus, methicillin-resistant Staphylococcus aureus, and streptococcal species after 2 doses given 12 hours apart. Mean MIC(90) were achieved for many gram-positive pathogens after only one dose in many patients after approximately 4 hours.