Biomedical subjects

Randall J Olson

Publications and source records attributed to Randall J Olson.

At least 19 recordsLinked to original sources

PubMed2007

Collagen shields as a drug delivery system for the fourth-generation fluoroquinolones.

PURPOSE: To evaluate the penetration of commercially available gatifloxacin and moxifloxacin into the anterior chamber of a rabbit eye using collagen shields presoaked in the antibiotics as a drug delivery system. METHODS: Collagen shields, presoaked for 10 min in commercially available solutions of gatifloxacin (diluted intravenous Tequin) or moxifloxacin (Vigamox) with the same concentration, were placed on the surface of each of the corneas of 12 rabbits for a total of 24 eyes (12 in each group). Aqueous humor samples were taken 3 and 6 h later. RESULTS: The concentrations of both antibiotics were high after 3 h (3.1 +/- 1.3 microg/ml for moxifloxacin and 2.3 +/- 0.8 microg/ml for gatifloxacin, p = 0.22). The concentration of gatifloxacin after 6 h was statistically significantly higher than for moxifloxacin (0.76 +/- 0.33 microg/ml vs. 0.29 + 0.14 microg/ml, respectively, p = 0.03). CONCLUSION: Our results suggest that collagen shields can be effective as a drug delivery system for the fourth-generation fluoroquinolones with a longer effect for gatifloxacin.

Animals↗

PubMed2006

Objective measurement of postocclusion surge during phacoemulsification in human eye-bank eyes.

PURPOSE: To objectively compare the postocclusion vacuum surge among different phacoemulsification machines and devices. DESIGN: Experimental study. METHODS: Infiniti, Legacy, Millennium, and Sovereign were tested in an eye-bank eye. All the machines were tested with 20-gauge non-ABS tips, 430 mm Hg vacuum pressure, 24 ml/minute aspiration rate, peristaltic pump, and 75 cm bottle height. In addition, Infiniti and Legacy were also tested with 20-gauge bypass tips (ABS), 125 cm bottle height, and 40 ml/minute flow rate. We also tested 19-gauge tips with Infiniti and Sovereign and the venturi pump for Millennium. RESULTS: Significant differences were found between all the machines tested with Millennium peristaltic generating the least and Millennium Venturi the most surge. ABS tips significantly decreased the surge for Legacy but not for Infiniti. Cruise Control (CC) had a significant effect on Sovereign but not on Millennium. Increasing the bottle height decreased surge while increasing the flow increased surge for both Infiniti and Legacy. The 19-gauge tips increased surge for both Infiniti and Sovereign. CONCLUSIONS: Surge varied over a range of 40 microm to more than 2 mm. ABS and CC decrease surge, especially when the machine is not functioning near the limits of surge prevention. Certain parameters, such as a 19-gauge tip and high flow, dramatically increased surge, whereas elevating the bottle ameliorates it. Understanding the impact of all these features will help in minimizing the problem.

Eye↗

PubMed2006

A survey about phacoemulsification incision thermal contraction incidence and causal relationships.

PURPOSE: To ascertain the rate and related factors of phacoemulsification wound burns. DESIGN: Survey. METHODS: We conducted a survey of 523 ophthalmologists in Utah, Colorado, Montana, South Dakota, and Oregon. RESULTS: One hundred six doctors (20.3%) responded and provided data on 76,581 procedures and 75 wound burns (0.98/1000 procedures). Twenty-one wounds (28%) occurred during early sculpting, and 53 wounds (71%) occurred during fragment removal. Wound burns were found to be associated with surgical approach (P = .003), phacoemulsification unit (P = .007), and unit settings (P < .001). CONCLUSION: Wound burns continue to be a serious complication; however, advances in technology and surgical technique help.

Body Temperature↗

PubMed2006

Phacodynamics: an aspiration flow vs vacuum comparison.

PURPOSE: To compare actual flow and the vacuum necessary to generate that flow for the Advanced Medical Optics Sovereign (Advanced Medical Optics, Santa Ana, California, USA) and the Alcon Legacy (Alcon, Fort Worth, Texas, USA) phacoemulsification machines. DESIGN: In vitro laboratory study. METHODS: Flow was collected and machine indicated vacuum noted from 12 ml/min to 40 ml/min in 2 ml/min steps (20-gauge). Nineteen and 20-gauge tips were also compared. Machine indicated vacuum was converted to actual tip vacuum. RESULTS: Legacy flow (102.4 +/- 3.8% of indicated) was significantly more than Sovereign (96.5 +/- 3.9%; P < .0001). 20-gauge flow was less than 19-gauge flow (96.1% vs 98.6% of indicated, P < .0001). Sovereign had less unoccluded vacuum (70.3 +/- 3.2 mm Hg) than Legacy (89.4 +/- 1.2 mm Hg) at 36 ml/min of flow (P < .0001 for 26 to 36 ml/min of flow). CONCLUSION: There is unoccluded vacuum at the phaco tip of these systems at 14 ml/min, of flow and at 40 ml/min, this was 112.0 mm Hg for the Legacy.

Phacoemulsification↗

PubMed2006

Fluidics and heat generation of Alcon Infiniti and Legacy, Bausch & Lomb Millennium, and advanced medical optics sovereign phacoemulsification systems.

PURPOSE: To study heat generation, vacuum, and flow characteristics of the Alcon Infiniti and Bausch & Lomb Millennium with results compared with the Alcon Legacy and advanced medical optics (AMO) Sovereign machines previously studied. DESIGN: Experimental study. METHODS: Heat generation with continuous ultrasound was determined with and without a 200-g weight. Flow and vacuum were determined from 12 to 40-ml/min in 2-ml/min steps. The impact of a STAAR Cruise Control was also tested. RESULTS: Millennium created the most heat/20% of power (5.67 +/- 0.51 degrees C unweighted and 6.80 +/- 0.80 degrees C weighted), followed by Sovereign (4.59 +/- 0.70 degrees C unweighted and 5.65 +/- 0.72 degrees C weighted), Infiniti (2.79 +/- 0.62 degrees C unweighted and 3.96 +/- 0.31 degrees C weighted), and Legacy (1.99 +/- 0.49 degrees C unweighted and 4.27 +/- 0.76 degrees C weighted; P < .0001 for all comparisons between machines except Infiniti vs Legacy, both weighted). Flow studies revealed that Millennium Peristaltic was 17% less than indicated (P < .0001 to all other machines), and all other machines were within 3.5% of indicated. Cruise Control decreased flow by 4.1% (P < .0001 for same machine without it). Millennium Venturi had the greatest vacuum (81% more than the least Sovereign; P < .0001), and Cruise Control increased vacuum in a peristaltic machine 35% more than the Venturi system (P < .0001). CONCLUSIONS: Percent power is not consistent in regard to heat generation, however, flow was accurate for all machines except Millennium Peristaltic. Restriction with Cruise Control elevates unoccluded vacuum to levels greater than the Venturi system tested.

Drainage↗

PubMed2006

Comparative clinical trial of ultrasound phacoemulsification with and without the WhiteStar system.

PURPOSE: To compare the postoperative outcomes of cataract surgery performed with the Sovereign 4.0 system or the Sovereign system with WhiteStar power modulation. SETTING: Ambulatory surgery centers at 4 sites in the United States. METHODS: This was a 3-month, open-label, randomized, parallel-group comparative clinical trial in patients with visually interfering cataract. Surgeons used the divide-and-conquer phacoemulsification technique for nuclear removal. An intraocular lens was implanted using the recommended insertion system. Primary operative outcome measures were equivalent phaco time (EPT), percentage of phaco power, amount of balanced salt solution used, and surgical complications. Patients were seen 1 day and 3 months after surgery. Postoperative outcome measures were the change in endothelial cell count from the preoperative visit to 3 months, corneal clarity, inflammation, and corneal thickness. RESULTS: The Sovereign with WhiteStar group had 48 patients and the Sovereign 4.0 group, 49 patients. Mean EPT and mean percentage of power were significantly lower in the Sovereign with WhiteStar group. Mean EPT was 6.67 seconds +/- 8.2 (SD) in the Sovereign with WhiteStar group and 8.59 +/- 9.3 seconds (P = .01) in the Sovereign 4.0 group. Mean percentage of phaco power was 6.41% +/- 3.3% in the Sovereign with WhiteStar group and 8.51% +/- 4.9% in the Sovereign 4.0 group (P = .01). The Sovereign with WhiteStar group lost significantly fewer endothelial cells (-319.6 +/- 634.2 cells/mm(2)) than the Sovereign 4.0 group (-430.3 +/- 594.6 cells/mm(2)) (P = .01). Corneal clarity, cells and flare, and pachymetry were comparable with the exception of the 3-month visit. The mean change in baseline central pachymetry showed significantly less corneal thickening in the Sovereign with WhiteStar group. CONCLUSIONS: The Sovereign with WhiteStar power modulation system provides effective lens removal at lower levels of phaco power and ultrasound energy than the Sovereign 4.0 system. Lower ultrasound levels may reduce the risk for endothelial cell loss during phacoemulsification.

Cell Count↗

PubMed2006

Comparison of thermal features associated with 2 phacoemulsification machines.

PURPOSE: To determine the thermal characteristics of the Legacy Advantec and Sovereign WhiteStar phacoemulsification machines during different clinically relevant scenarios. SETTING: In vitro study. METHODS: In water, temperature was recorded continuously on the sleeve in an artificial chamber, and the increase in temperature over baseline after 60 seconds of ultrasound was determined. This was done for continuous ultrasound, 50 ms on and 50 ms off (pulse), 6 ms on and 12 ms off (WhiteStar; Sovereign only) with aspiration blocked and not blocked, and with 100 g and 200 g weights suspended from the sleeve. RESULTS: Comparing temperature increase per 20% machine power increments, Sovereign ran hotter than Legacy Advantec for continuous ultrasound (2.31x) and pulse (2.23x). Blocking aspiration increased temperature over the unblocked state. Pulsing decreased temperature by 51% (Legacy Advantec, pulse), 52% (Sovereign, pulse), and 64% (WhiteStar). Weights had much more effect on the Legacy Advantec: 3.5 times more going from baseline to 100 g weights and 3.2 times more going from 100 to 200 g weights. For all these comparisons, the P value was less than 0.0001. CONCLUSIONS: The machines behaved fundamentally differently, with the Legacy Advantec controlling stroke length and Sovereign controlling a fixed power at any setting. Therefore, workload had a much bigger impact on Legacy Advantec thermal characteristics. Pulsing decreased heat produced directly related to the duty cycle. The most dangerous incision burn scenario is with continuous ultrasound, aspiration blocked, and a heavy workload.

Acetates↗

PubMed2006

Early opacification of silicone intraocular lenses: Laboratory analyses of 6 explants.

PURPOSE: To report laboratory analyses of 6 intraocular lenses (IOLs) explanted from patients who had visual disturbances caused by early postoperative opacification of the lens optic. SETTING: John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. METHODS: Six patients with 3-piece silicone lenses presented with optic cloudiness as early as a few hours after implantation. The lenses were implanted in 4 locations in Brazil and in France. The lenses in Brazil were stored at the same location before implantation. Gross and microscopic analyses were performed (dry and hydrated states). One half of each specimen underwent gas chromatography/mass spectrometry (GC/MS) analysis and/or extraction by isopropyl alcohol or acetonitrile. One lens also underwent scanning electron microscopy (SEM) with energy dispersive x-ray spectroscopy (EDS). The IOLs were examined for the presence of contaminants or deposits that could cause fast optic opacification. RESULTS: The IOLs showed a white optic discoloration in the hydrated state but became transparent on complete dehydration. Suspect exogenous chemical compounds were identified in GC/MS analyses; general classes included terpenes and ketones, typically found in industrial cleaning agents and fumigants. Surface analysis (SEM and EDS) did not show any significant deposits on the external surfaces and sagittal cut in 1 of the specimens. CONCLUSIONS: Most IOLs are enclosed in semipermeable packages to allow sterilization by ethylene oxide gas. During cleaning or disinfection of storage rooms, aerosolized solutions may introduce chemicals through the package and onto the IOLs. This may cause surface changes in the IOL, promoting opacification by water ingress in the aqueous environment. Cleaning and disinfection procedures of IOL storage areas should be monitored carefully.

Aged↗

PubMed2006

Hydrophilic acrylic intraocular lens as a drug-delivery system: Pilot study.

PURPOSE: To evaluate the ability of a hydrophilic acrylic intraocular lens (IOL) to serve as a drug-delivery system for commercially available gatifloxacin and moxifloxacin. SETTING: David J. Apple, MD, Laboratories for Ophthalmic Devices Research, John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. METHODS: Hydrophilic acrylic IOLs (C-flex, Rayner Ltd.), presoaked for 24 hours in commercially available solutions of gatifloxacin (Zymar) or moxifloxacin (Vigamox), were implanted in the capsular bag of 6 rabbits for a total of 12 eyes (6 in each group). Aqueous humor samples were taken 2, 4, and 6 hours after implantation. One rabbit served as a control and had nonpresoaked C-flex IOLs implanted. At the end of the operation, 1 drop of Vigamox was applied to the right eye and 1 drop of Zymar was applied to the left eye of the control rabbit. RESULTS: High concentrations of both antibiotics were found in all the samples of the eyes implanted with the presoaked IOLs. The concentrations of the antibiotics decreased over time, but even the 6-hour sample concentrations were markedly higher than the concentrations found in the control rabbit after 4 hours. CONCLUSION: The results suggest that the Rayner C-flex IOL can be effective as a drug-delivery system for fourth-generation fluoroquinolones.

Acrylic Resins↗

PubMed2006

Effect of incisional friction and ophthalmic viscosurgical devices on the heat generation of ultrasound during cataract surgery.

PURPOSE: To determine the thermal features of the Legacy (Alcon) and Sovereign (Advanced Medical Optics) phacoemulsification machines in a cadaver eye and with 7 ophthalmic viscosurgical devices (OVDs). SETTING: In situ and in vitro study. METHODS: Temperature without occlusion was recorded at the sleeve placed in the wound of a cadaver eye, and temperature over baseline was determined after 60 seconds. The result was then compared with the results in a previous study that used balanced salt solution (BSS) in artificial chambers. In the second portion of the experiment, with irrigation and aspiration lines occluded, temperature was recorded at the sleeve placed in an artificial chamber filled with sodium hyaluronate 2.3% (Healon5), sodium hyaluronate 1.4% (Healon GV), sodium hyaluronate 1.0% (Healon), sodium hyaluronate 1.6% (Amvisc Plus), sodium hyaluronate 1.0% (Provisc), sodium hyaluronate 3.0%-chondroitin sulfate 4.0% (Viscoat), or hyaluronate 3.0% (Vitrax). Temperature over baseline was also determined after 60 seconds. These results were compared with each set of OVD data and with the results in the prior BSS study. RESULTS: In the eye-bank model, the Legacy machine had a 62% temperature increase from incisional friction and the Sovereign machine had a decrease of 8.6% over results in an artificial anterior chamber. The OVD temperature increases were greater for the Sovereign (P<.001) and followed the same general trend for the Legacy. The least temperature increase was with Amvisc Plus, Healon, and Healon GV; the intermediate increases were with Provisc and Vitrax; and the greatest increases were with Viscoat and Healon5. The OVD findings did not correlate with viscosity or pseudoplasticity. CONCLUSIONS: Incisional friction alone increased heat generation in the Legacy, a stroke-length driven instrument, more than in the Sovereign, a power-driven instrument. Ophthalmic viscosurgical devices are not only a concern due to outflow occlusion but can also add up to 6 times the heat in comparison with BSS. The need to aspirate the OVD before using ultrasound is thus verified.

Aged↗

PubMed2006

Thermal inertia associated with ultrapulse technology in phacoemulsification.

PURPOSE: To determine whether very short pulses of ultrasound (5 to 6 milliseconds) have less heat propagation in biological tissue (thermal inertia) than traditional pulses (50 milliseconds). SETTING: Department of Ophthalmology and Visual Sciences, University of Utah Health Sciences Center, Salt Lake City, Utah. METHODS: Thermal testing was done in balanced salt solution (BSS) and in eye-bank eyes. In the same fresh human eye-bank eye, net temperature increase after 20 seconds of ultrasound (50 milliseconds on and 50 milliseconds off) was compared with the increase after 6 milliseconds on and 12 milliseconds off with the same phacoemulsification unit. The same experiment and setting was run in BSS and the eye-bank ratios compared with the BSS ratios. Twenty runs were done at each power setting in BSS and 22 in the eye-bank eye. RESULTS: There was 10.9% less heat generated with 6-millisecond pulses of ultrasound in limbal tissue than in BSS compared with 50-millisecond pulses of ultrasound (P = .0002). CONCLUSION: Very short pulses of ultrasound (5 to 6 milliseconds) propagated less thermal energy in limbal tissue than in BSS compared with 50-millisecond ultrasound pulses.

Acetates↗

PubMed2006

Phacoemulsification tip vacuum pressure: Comparison of 4 devices.

PURPOSE: To determine the vacuum pressure generated by 4 phacoemulsification devices measured at the phacoemulsification tip. SETTING: University ophthalmology department. METHODS: The effective vacuum pressures generated by the Sovereign (AMO), Millennium (Bausch & Lomb), Legacy AdvanTec (Alcon Laboratories), and Infiniti (Alcon Laboratories) phacoemulsification machines were measured with a device that isolated the phacoemulsification tip in a chamber connected to a pressure gauge. The 4 machines were tested at multiple vacuum limit settings, and the values were recorded after the foot pedal was fully depressed and the pressure had stabilized. The AdvanTec and Infiniti machines were tested with and without occlusion of the Aspiration Bypass System (ABS) side port (Alcon Laboratories). The Millennium machine was tested using venturi and peristaltic pumps. RESULTS: The machines generated pressures close to the expected at maximum vacuum settings between 100 mm Hg and 500 mm Hg with few intermachine variations. There was no significant difference between pressures generated using 19- or 20-gauge tips (Millennium and Sovereign). The addition of an ABS side port decreased vacuum by a mean of 12.1% (P < .0001). CONCLUSION: Although there were some variations in vacuum pressures among phacoemulsification machines, particularly when an aspiration bypass tip was used, these discrepancies are probably not clinically significant.

Phacoemulsification↗

PubMed2006

Hydrophilic acrylic intraocular lens as a drug-delivery system for fourth-generation fluoroquinolones.

PURPOSE: To evaluate the ability and safety of a hydrophilic acrylic intraocular lens (IOL) as a drug-delivery system for commercially available gatifloxacin and moxifloxacin. SETTING: David J. Apple, MD, Laboratories for Ophthalmic Research, John A. Moran Eye Center, Department of Ophthalmology and Visual Sciences, University of Utah, Salt Lake City, Utah, USA. METHODS: Thirty rabbits were divided into 2 similar groups. In Group A (15 rabbits, 30 eyes), hydrophilic acrylic IOLs (C-flex, Rayner Intraocular Lenses, Ltd.) presoaked for 24 hours in commercially available solutions of gatifloxacin 3 mg/mL or moxifloxacin 5 mg/mL were implanted after evacuation of the crystalline lens. Group B (15 rabbits, 30 eyes) had topical preoperative and postoperative cataract prophylaxis with gatifloxacin 3 mg/mL or moxifloxacin 5 mg/mL; IOLs that were not presoaked were also implanted after evacuation of the crystalline lenses. In both groups, aqueous humor samples were taken 4, 8, or 12 hours after IOL implantation (5 eyes at each time point) to determine the antibiotic concentrations. Clinical examinations were performed 24 hours postoperatively. RESULTS: The antibiotic concentrations in Group A (presoaked IOLs) were statistically significantly higher than those in Group B (topical) for both antibiotics in all postoperative samples except moxifloxacin at 12 hours. In both groups, there was no statistically significant difference between the concentrations of the 2 antibiotics. No eye showed signs of clinical toxicity. CONCLUSION: Results show the C-flex IOL is a safe and effective drug-delivery system for fourth-generation fluoroquinolones.

Acrylic Resins↗

PubMed2006

New technology IOL optics.

There has been a rapid evolution in the field of intraocular lens (IOL) manufacture, much of it influenced by the development of microincision surgical techniques and wavefront aberrometry.Thi article discusses new technology that has been applied to modern IOL optics, including multifocal, toric, blue-blocker, accommodative, and aspheric IOLs; lenses designed to be inserted through sub 2-mm incisions; and an implantable telescope for macular degeneration.

Humans↗

PubMed2006

Intraocular concentrations of gatifloxacin and moxifloxacin in the anterior chamber via diffusion through the cornea using collagen shields.

PURPOSE: To evaluate the penetration of gatifloxacin and moxifloxacin into the anterior chamber, and any adverse reaction to the cornea, using collagen shields presoaked in oversaturated solutions of the antibiotics. METHODS: Collagen shields, presoaked for 10 minutes in an oversaturated solution of gatifloxacin or moxifloxacin, were placed on the surface of each of the corneas of 15 rabbits for a total of 30 eyes (15 in each group). The antibiotics were prepared by dissolving the powder form of the antibiotics in a solution until no further particulate could be further dissolved. Aqueous humor samples were taken 3.5 and 6 hours later. RESULTS: The initial concentrations of gatifloxacin and moxifloxacin were 5.43 +/- 0.16 mg/mL and 3.14 +/- 0.22 mg/mL, respectively. The average concentration of gatifloxacin in the anterior chamber was higher than that of moxifloxacin at the 3.5-hour sample (6.32 +/- 2.67 microg/mL versus 3.55 +/- 3.5 microg/mL, P = 0.0034). The concentrations of both antibiotics, although decreased, remained relatively high at the 6-hour sample (1.39 +/- 1.13 microg/mL versus 0.816 +/- 0.6 microg/mL at 6 hours, respectively, P = 0.22). No obvious clinical or histologic signs of toxicity were noticed in either group. CONCLUSION: Gatifloxacin and moxifloxacin showed good penetration into the anterior chamber with no obvious adverse reaction to the cornea. The concentrations in the anterior chamber exceeded the minimal inhibitory concentration (MIC) 90 of most organisms responsible for postoperative endophthalmitis (POE).

Animals↗

PubMed2006

Analysis of an approach to astigmatism correction during cataract surgery.

PURPOSE: To determine if a system of astigmatic keratomy at the time of cataract surgery is safe and effective. SETTING: Academic Ophthalmology Center. METHODS: One hundred and ten consecutive patients with greater than 0.50 diopters (d) of cylinder with the rule (WTR) and 0.75 d against the rule (ATR) were enrolled. Those with an axis between 16 and 74 degrees and 106 and 164 degrees were defined as oblique axis. Peripheral clear corneal relaxing incisions 600 mum deep were used with a nomogram of 60 degrees length per 1.0 d of attempted correction. Keratometry was taken from IOL Master biometry and refractive results at 4-12 weeks were compared. RESULTS: 60.5% of ATR, 62% of WTR and 23% of oblique attempted correction was achieved. Splitting the patients to under and over 70 years of age had no impact on the results. Of the 14 overcorrected, 7 had oblique cylinder (p = 0.009) and 10 had less than 1 d of preoperative cylinder (p = 0.00015). CONCLUSIONS: Using the IOL Master topography with this nomogram was quite effective in reducing preoperative cylinder. Oblique axis results were unpredictable, however, and much more likely to lead to an overcorrection.

Aged↗

PubMed2005

New intraocular lens technology.

PURPOSE: To review the current status of phakic intraocular lenses (IOLs), intraocular treatment of presbyopia, and IOLs that filter some blue light. DESIGN: Review of current information on the subject from numerous sources. METHODS: Medline search and Internet search engines on the topics of phakic IOLs, presbyopia or multifocal IOLs, and blue light and macular degeneration. RESULTS: An iris fixated phakic IOLs is now approved in the United States (US). There are concerns for corneal endothelial stability and late dislocation. Other approaches include anterior chamber fixation with concerns of corneal endothelial stability and pupil elongation, and posterior chamber fixation with concerns of cataract formation, IOL dislocation, and pigment dispersion. Intraocular treatment of presbyopia includes monovision, multifocal, and accommodative IOLs. Which approach is superior today is still not clear. There are IOLs designed to block some blue light to potentially lessen the risk of age-related macular degeneration (ARMD). While there is presumptive evidence of this, no definitive study shows such a correlation. Color perception issues are unlikely to be a problem. While decreased scotopic vision has been proposed, there is no study that proves this is an issue of clinical significance. CONCLUSIONS: The IOL field is dynamic with many new choices. Phakic IOLs and treatment of presbyopia will be an increasingly important part of ophthalmology; however, there are important unresolved issues. With better evidence that blue light is an important variable in ARMD, such an approach could rapidly become the standard.

Biomedical Technology↗

PubMed2005

A retrospective study of endophtalmitis rates comparing quinolone antibiotics.

PURPOSE: To compare endophthalmitis rates between topical quinolone antibiotics over a four-year period in a university setting. DESIGN: Retrospective, cross-sectional (prevalence) study. METHODS STUDY POPULATION: Nine thousand seventy-nine patients who underwent a phacoemulsification procedure at a University Eye Center. INTERVENTIONS: The following interventions were conducted: use of a nosocomial infectious reporting database retrospective analysis of prospectively collected data to establish endophthalmitis rates; prevalence analysis of postoperative quinolone antibiotics; analysis of endophthalmitis rate vs postoperative quinolone prescribed. MAIN OUTCOME MEASURES: Occurrence of endophthalmitis after cataract surgery. RESULTS: During a four-year period involving 9079 phacoemulsification procedures, 26 cases of bacterial postoperative endophthalmitis were reported (rate = 0.286%). Eight of the 26 cases were considered complicated; 18 cases were uncomplicated. Among cases performed during this period, postoperative prescription volumes for ciprofloxacin (Ciloxan, Alcon Laboratories, Inc., Fortworth, Texas) and ofloxacin (Ocuflox, Allergan, Inc., Irvine, California) antibiotic drops were nearly identical, with 4538 patients receiving ciprofloxacin (49.98%) and 4541 patients receiving ofloxacin (50.02%). There were 22 endophthalmitis patients (85%) who had used topical ciprofloxacin and 4 patients (15%) who had used topical ofloxacin postoperatively. The difference in infectious rates between antibiotics was highly significant (P < .00026). For uncomplicated cases, 14 patients received ciprofloxacin and 4 patients received ofloxacin. This difference was also significant (P < .015). CONCLUSIONS: Differences in pharmacokinetic and pharmacodynamic properties exist among quinolone antibiotics, which may affect endophthalmitis incidence following cataract surgery.

Administration, Topical↗