In vitro susceptibilities to topical antibiotics of bacteria isolated from the surface of clinically symptomatic eyes.

BACKGROUND: The permanent change of resistance patterns of bacteria causing ocular infections makes repeat susceptibility testings against the most recent clinical isolates mandatory. The aim of the present study was to assess the in vitro susceptibility of ocular bacterial isolates of clinically symptomatic eyes admitted to the outpatient clinic of the eye department of a large central hospital to commonly used topical antibiotics. METHODS: Ocular isolates (n = 454) were tested for their susceptibility to ofloxacin, ciprofloxacin, norfloxacin, gentamicin, tobramycin, meomycin, bacitracin, erythromycin, tetracycline and chloramphenicol. RESULTS: All three tested fluoroquinolones were found to be very effective against gram-negative organisms but demonstrated some weakness against certain strains of gram-positive germs, in particular coagulase-negative staphylococci and Streptococcus viridans. These germs, however, were very susceptible to bacitracin and chloramphenicol. The relative overall in vitro efficacy was (in decreasing order): chloramphenicol, ciprofloxacin, ofloxacin, norfloxacin, bacitracin, tetracycline, neomycin, erythromycin, tobramycin and gentamicin. CONCLUSION: Chloramphenicol had the highest overall in vitro efficacy, but has potential lethal side effects. The fluoroquinolones were highly effective, especially being superior to the aminoglycosides tested, but no single antibiotic provided 100% coverage against all of the bacterial isolates that were tested.

One year results of European Multicenter Study of intrastromal corneal ring segments. Part 1: refractive outcomes.

PURPOSE: To assess the efficacy, predictability, stability, and safety of correcting myopia with intrastromal corneal ring segments (ICRS, KeraVision, Inc.). SETTING: Twelve European investigational sites. METHODS: Patients with myopia of -1.0 to -6.0 diopters (D) and best spectacle-corrected visual acuity (BSCVA) of 20/20 or better (except in 3 eyes) were assigned to receive 1 of 5 ICRS thicknesses (0.25, 0.30, 0.35, 0.40, or 0.45 mm). Efficacy was assessed by postoperative uncorrected visual acuity (UCVA), predictability of refractive outcome (deviation from predicted cycloplegic refraction spherical equivalent), and stability of refractive effect (manifest refraction spherical equivalent [MRSE]). Safety was assessed by maintenance or loss of preoperative BSCVA and induced manifest refraction cylinder. Measurements were made preoperatively and 1 and 7 days and 1, 2, 3, 6, and 12 months postoperatively. RESULTS: One hundred fifty-nine ICRSs were implanted in the eyes of 107 patients (52 patients had bilateral implantation). Preoperatively, UCVA was worse than 20/40 in 98% of eyes (155/159); 12 months postoperatively, it was 20/20 or better in 63% of eyes (83/132) and 20/40 or better in 96% (127/132). Predicted refractive corrections for each ICRS thickness generally correlated with achieved corrections. At 12 months postoperatively, 90% of eyes (124/138) were within +/-1.00 D of plano (MRSE). Two or more lines of BSCVA were lost in 6% of eyes (8/135); all 8 eyes had BSCVAs of 20/25 or better. CONCLUSION: The ICRS safely, effectively, and predictably reduced or eliminated low to moderate myopia. Refractive correction was stable through the 12 month follow-up.

One year results of European Multicenter Study of intrastromal corneal ring segments. Part 2: complications, visual symptoms, and patient satisfaction.

PURPOSE: To assess intraoperative and postoperative complications, visual symptoms, and patient satisfaction after implantation of intrastromal corneal ring segments (ICRS, KeraVision, Inc.) for the correction of myopia and to demonstrate the reversibility and adjustability of refractive corrections with this method. SETTING: Twelve European investigational sites. METHODS: Patients with myopia of -1.0 to -6.0 diopters (D) were assigned to receive 1 of 5 ICRS thicknesses (0.25, 0.30, 0.35, 0.40, or 0.45 mm). Complications and visual symptoms were noted, and patient satisfaction was assessed at each postoperative visit (1 and 7 days and 1, 2, 3, 6, and 12 months). Refractive data were assessed after removal or exchange of the ICRS. RESULTS: Of 163 eyes of 110 patients enrolled, 159 eyes of 107 patients were implanted with an ICRS (52 patients had bilateral implantation). Intraoperative complications occurred in 2% of eyes (4/163 eyes in 3 patients) that were withdrawn from the study: 3 eyes had anterior surface perforations and 1 had a posterior microperforation into the anterior chamber. Most patients had no visual symptoms at 12 months; symptoms usually occurred rarely or sometimes and were mild in severity. At 12 months, good or excellent patient satisfaction was reported for 94% of eyes. Twelve ICRSs (8%) were removed, mainly because of undercorrection and induced astigmatism, and 2 were exchanged. All eyes were within +/-1.00 D of the preoperative manifest refraction spherical equivalent. CONCLUSIONS: The ICRS was safe for correction of low to moderate myopia. Severe postoperative visual symptoms were rare, and patient satisfaction was high. The refractive correction was largely reversible.

Confocal microscopy after implantation of intrastromal corneal ring segments.

OBJECTIVE: Confocal in vivo real-time microscopy was used to study the corneal morphologic features in eyes after Intrastromal Corneal Ring Segments (ICRS; now called KeraVision INTACS, KeraVision, Inc., Fremont, CA) implantation. DESIGN: Noncomparative, interventional case series. PARTICIPANTS: The authors performed confocal real-time microscopy on a total of 21 eyes from 11 patients. Seventeen eyes from 10 patients (five female, five male; mean age 32.3 years; range 22-42 years) underwent uncomplicated ICRS surgery to correct myopia and were examined after surgery (average 8.6 months; range 2-15 months). Three patients had the ICRS implanted into only one eye, and those eyes were compared with the untreated fellow eyes. One eye of another patient was examined 1 and 6 months after ICRS removal. INTERVENTION: Flying slit-confocal microscopy was performed with water immersion objectives in the corneal center and near the nasal or temporal ICRS. Corneal optical sections were recorded in real time without further digital processing and were reviewed frame by frame. MAIN OUTCOME MEASURES: Video frames selected from all corneal layers were evaluated qualitatively and quantitatively. RESULTS: In the central cornea, we found normal morphologic features at all layers. In peripheral sections, epithelial cells with highly reflective nuclei in the basal cell layer were observed in six of 17 eyes (35%) implanted with ICRS. We found an intact corneal nerve plexus and undisturbed corneal endothelium immediately underneath the ICRS. Around the ICRS, moderate fibrosis was seen. In one eye, linear structures in bamboo-like orientation were detected after ICRS removal in the last keratocyte layer underneath the collapsed tunnel. CONCLUSIONS: Whereas the central corneal zone appears unchanged, the corneal stroma adjacent to the ICRS displays a slight, but distinct, activation of wound healing. Epithelial cells with highly reflective nuclei in this region may be an indicator for an increased biologic stress caused by the device.

Recurrent keratoconus in a patient with Leber congenital amaurosis.

PURPOSE: Clinical history of a 17-year-old patient with Leber congenital amaurosis (LCA) with histologically proven recurrent keratoconus (KC) two years after corneal transplantation in one eye and a recurrence-like appearance with a more global contour on the other eye four years after corneal grafting is reported. The possible mechanisms for this recurrence are discussed in light of the fact that this is, to the best of our knowledge, the first penetrating keratoplasty reported in LCA. METHODS: Computerized videokeratography (CVKG) and specular microscopy were performed preoperatively. The patient underwent regrafting, and the excised corneal button was examined by light microscopy and transmission electron microscopy. RESULTS: Analysis of CVKG showed a keratoconus-like pattern on the right eye, with the left eye demonstrating the aspects usually seen in keratoglobus. Histologic examination revealed the features usually observed in progressed keratoconus. CONCLUSION: Recurrence of keratoconus in a graft has not yet been described after such a short time until now. A "true" recurrence of the disease is postulated; it could be caused by an "aggressive" genetic factor that also leads to the frequent KC in patients with LCA. This mechanism also could explain the high incidence and rapid progress of KC in this disease.

[Intrastromal corneal ring segments (ICRS, KeraVision Ring, Intacs): clinical outcome after 2 years]. / Intrastromale Corneale Ringsegmente (ICRS, KeraVision Ring, Intacs): Klinische Ergebnisse nach 2 Jahren.

BACKGROUND: Since 1996 Intrastromal Corneal Ring Segments (Intacs, KeraVision, Inc., Fremont, CA, USA) have been used for the correction of mild to moderate myopia at the Salzburg Eye Clinic. Aim of this study was to evaluate the stability, reversibility and adjustability of this new method. PATIENTS AND METHODS: Our experiences and final results of 54 surgeries--30 eyes with a minimum follow-up of 2 years--, as well as the potential reversibility (3 explanations, 2 of them followed by PRK) and adjustability (3 exchanges) are reported in detail. RESULTS: None of the eyes lost more than one line in BSCVA (in 14 of 30 eyes the BSCVA improved, "Safety-Index": 1.13). 73% (22/30) reached an UCVA of 1.0 or better, 47% (14/30) of 1.25 or better ("Efficacy-Index": 0.79). After two years 47% (14/30) were within +/- 0.5 D of the attempted correction. We observed no significant intra- or postoperative complications. After ICRS removal the refractive data returned to within +/- 0.75 D (MRSE) and +/- 0.5 D (mean keratometry) of preoperative values, respectively. Patients with an ICRS exchange obtained an improved UCVA between 0.8 and 1.0, gaining between 2 to 4 lines. CONCLUSIONS: Within the follow-up period of 2 years the ICRS seem to provide a very stable correction of low to moderate myopia. The procedure is reversible to a large extent, potentially adjustable (within certain limits) and carries a minimal risk only. After explantation PRK can be performed with good visual results.

Penetration of cefpirome into the anterior chamber of the human eye after intravenous application.

The penetration of intravenously administered cefpirome into the anterior chamber of the non-inflamed human eye was investigated in this study. A total of 42 patients, all hospitalized for cataract extraction, received a dosage of 1 g or 2 g of cefpirome by iv infusion 1, 2 or 6 h preoperatively. An aqueous humour sample was collected immediately after paracentesis and a blood specimen was simultaneously obtained from each patient. All samples were analysed for cefpirome concentrations using high-pressure liquid chromatography. Mean aqueous humour levels of cefpirome in patients receiving a dosage of 1 g were 1.33 mg/L (1 h), 1.67 mg/L (2 h) and 1.29 mg/L (6 h after application), respectively. When patients received a dosage of 2 g cefpirome the resulting mean aqueous humour concentrations were 1.60 mg/L (1 h), 2.27 mg/L (2 h) and 2.39 mg/L (6 h after application), respectively. A statistically significant difference in aqueous humour concentrations between patients receiving 1 g or 2 g of cefpirome could not be proven. In conclusion, cefpirome penetrates well into the anterior chamber of the non-inflamed human eye in concentrations that are therapeutic for many gram-positive and gram-negative organisms, frequently responsible for anterior segment eye infections.

Dodick photolysis for cataract surgery: early experience with the Q-switched neodymium: YAG laser in 100 consecutive patients.

OBJECTIVE: To evaluate the safety and efficacy of a Q-switched neodymium:YAG (Nd:YAG) laser for removal of the human cataract. DESIGN: A multicenter, prospective, noncomparative study. PARTICIPANTS: A total of 100 consecutive eyes undergoing cataract extraction with the Dodick Photolysis, Q-switched Nd:YAG laser. MAIN OUTCOME MEASURE: Corneal endothelial cell loss, visual acuity improvement, intraocular pressure change, total intraocular energy used, and intraoperative and postoperative complications. RESULTS: The mean values were postoperative visual acuity improvement from 20/46.5 (0.43) to 20/26.6 (0.75), decrease in endothelial cell count of 177 cells/mm2 (7.55%), and intraocular energy used of 6.7 J. Minor complications were encountered in three cases. CONCLUSIONS: These data suggest that Dodick Photolysis may be a safe and effective new technology for cataract removal in human eyes. It appears to offer low intraocular energy and heat release, a clear-cornea incision less than 1.5 mm in size, and safe operation within the capsular bag.

Corneal wound healing after superficial foreign body injury: vitamin A and dexpanthenol versus a calf blood extract. A randomized double-blind study.

A prospective randomized double-blind clinical study was performed to investigate corneal wound healing after treatment either with an eye gel containing calf blood extract or an eye ointment containing vitamin A and dexpanthenol. A total of 54 outpatients were included in this study, all treated for corneal foreign body injury. The size of the corneal lesions was measured by planimetry on days 0, 1, and on the following days until complete epithelial healing occurred. Results showed the calf blood extract eye gel to be statistically more effective in promoting corneal wound healing, especially in patients with wound areas larger than 6 mm(2).

Dodick laser phacolysis: thermal effects.

PURPOSE: To gather experimental data on whether Dodick laser phacolysis leads to corneal or scleral burns. SETTING: The Eye Department, County Hospital Salzburg, Salzburg, Austria. METHODS: The study was done using a pulsed neodymium:YAG (Nd:YAG) laser with a wavelength of 1064 nm; energy, 10 mJ; and duration of pulses, 14 ns. The light pulse is carried by a 400 microns quartz fiber to the laser phacolysis probe. The laser light hits a titanium target inside the tip, causing an optical breakdown and thus a shock wave. The generation of both plasma and the shock disrupt the nuclear material. The temperature at the ultrasonic phaco and laser phacolysis tip was measured under air and balanced salt solution (BSS) in a test chamber and in the anterior chambers of eye-bank eyes. RESULTS: Ultrasonic phacoemulsification led to a difference in temperature up to 55.3 degrees C under air, 12 degrees C in BSS, and 10.9 degrees C in the anterior chamber. There was no clinical significant heat generated by the laser phacolysis tip. CONCLUSION: This initial in vitro study demonstrates that the well-known risk of the tissue heating (i.e., phaco burn) does not occur with Dodick laser phacolysis, even when the irrigation flow is slow or discontinued.

Glass-ionomer cement: evaluation as an orbital implant.

BACKGROUND: To assess the potential of a porous glass-ionomer cement (GIC) as an alternative material for spherical orbital implants, the handling, side effects and rates of fibrovascular ingrowth of this material were compared with those of a synthetic hydroxyapatite (HA) implant. METHOD: Twenty-one GIC and 8 HA uncovered 14-mm spheres were implanted into the orbits of New Zealand albino rabbits. Postoperative reactions, animal's behaviour, weight increase and socket conditions were monitored. Light and electron microscopy of the exenterated orbits were performed 2, 3 and 6 months after primary insertion. RESULTS: Implanting of GIC was easier than HA. Postoperatively all animals did well. Three HA and 1 GIC implant caused conjunctival dehiscences, but no implant extrusion was observed. Histologically, both materials caused mild inflammation in the surrounding connective tissue capsule, decreasing with time. GIC implants proved to be not truly porous, with only peripheral pores partly occupied by relatively acellular collagenous connective tissue. Free glass particles were observed in both the connective tissue and giant cells, occupying the partly filled pore spaces. HA implants showed extensive ingrowth of vital host tissue from the beginning. CONCLUSIONS: Considering the clinical findings and the mild inflammation in the connective tissue capsule surrounding both materials, they would appear to be equally well tolerated at the implant site. The significantly different microstructure and the histological results make GIC, despite better handling, less suitable as an orbital implant.

[Intrastromal corneal ring segments (ICRS, Kera Vision Ring). One year outcome of the first 25 interventions]. / Intrastromale Corneale Ring Segmente (ICRS, Kera Vision Ring). Einjahresergebnisse der ersten 25 Eingriffe.

BACKGROUND: The advantages of the Intrastromal Corneal Ring Segments (ICRS) as compared to the frequently used methods for the correction of low to moderate myopia (RK, PRK, LASIK) are the intact optical zone and nearly complete reversibility. PATIENTS AND METHODS: Two ICR-Segments, made of PMMA (with an arc length of 150 degrees each) are placed in the deep stromal layers via a small radial incision. At the Landesaugenklinik Salzburg 25 continuous surgeries were performed as part of the European "MECCA-trial". RESULTS: Refractive results, intra- and postoperative complications with a follow-up of 12 months are presented. There was no visual loss after one year. In 40% (10/25) the best corrected visual acuity remained unchanged. In 56% (14/25) one line was gained, once two lines were gained. The spherical equivalent was slightly in the range of undercorrection--as wanted. The refractive astigmatism increased (0.5 dpt). The keratoscopy image showed positive aspheric appearance. CONCLUSION: The ICRS (Kera Vision Ring) seems to offer a precise and stable method to correct low myopia. The procedure is reversible to a large extent, potentially adjustable within certain limits and carries a minimal risk only. Although long-term follow-up is not available yet, initial results of the technique seem very promising.

Anterior chamber contamination during cataract surgery with intraocular lens implantation.

PURPOSE: To measure anterior chamber bacterial and fungal contamination at the beginning and end of cataract surgery with intraocular lens (IOL) implantation in a large series of patients and to determine the influence of preoperative treatment and operative technique on contamination. SETTING: Department of Ophthalmology, County Hospital of Salzburg, Austria. METHODS: This prospective study comprised 700 consecutive patients having planned cataract extraction (511 phacoemulsification, 189 extracapsular cataract extraction [ECCE]). Thirty-four patients required an anterior vitrectomy; 8 myopic patients did not receive an IOL. A preoperative smear and two intraoperative (at the beginning and end of surgery) anterior chamber aspirates were obtained from each patient. Postoperative smears were obtained at discharge. Three preoperative treatments were evaluated: no lacrimal system irrigation, no topical antibiotic (n = 282); lacrimal system irrigation with balanced saline solution, no topical antibiotic (n = 243); lacrimal system irrigation, antibiotic (neomycin) eyedrops (n = 175). All patients received topical indomethacin twice a day preoperatively. RESULTS: Preoperative conjunctival smears showed bacterial growth in 76.6% of eyes, with coagulase-negative staphylococci (75%) the most common bacteria. Anterior chamber aspirates were culture positive in 14.1% at the beginning and in 13.7% at the end of surgery, with coagulase-negative staphylococci and corynebacteria the most common. Contamination rates of conjunctival smears taken at discharge were significantly lower (35%) than those taken preoperatively. There was no statistically significantly higher risk of anterior chamber contamination in eyes having ECCE than in those having phacoemulsification. Preoperative treatment did not statistically significantly influence intraoperative aqueous humor contamination rates. There were no cases of acute postoperative endophthalmitis. CONCLUSION: Bacteria entered the anterior chamber during cataract extraction and remained there at the end of surgery in a significant percentage of patients. Surgical technique, preoperative antibiotics, and preoperative lacrimal system irrigation had no statistically significant effect on contamination.

[The intrastromal corneal ring (KeraVision Ring, ICR, ICRS). A modern method for correcting minor myopia]. / Der Intrastromale Corneale Ring (KeraVision Ring, ICR, ICRS). Eine moderne Methode zur Korrektur der geringen Myopie.

For the correction of low myopia several competing surgical methods have been developed over the last two decades: radial keratotomy (RK) and photorefractive keratectomy (PRK) are used clinically on a very large scale. Both techniques are basically irreversible. RK does structurally weaken the cornea and PRK has to be applied directly at the optical center. Both disadvantages can to a large extent be avoided by the recently introduced Intrastromal Corneal Ring (ICR) that is now implanted worldwide following a long experimental and clinical development phase. The device is manufactured from PMMA and is effective by volume addition in the corneal periphery, shortening of the central arc length and thereby flattening the central optical zone. The latest development uses two ICR-Segments (with an arc length of 150 degrees each) that are placed in the deep stromal layers via a small radial incision. The surgical details, refractive results and intra- and postoperative complications of both, several international studies (with up to 5 years of follow-up), and our own experiences (25 eyes, follow-up 9 months) are presented. The ICRS (KeraVision Ring) seems to offer a precise and stable method to correct low myopia. The procedure is reversible to a large extent, potentially adjustable within certain limits and carries a minimal risk only. A short comparison with RK and PRK is attempted. Although long-term follow-up is not available yet, initial results of the technique seem very promising.