Josef Ruckhofer

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.

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.

Clinical characteristics of lamellar channel deposits after implantation of intacs.

Purpose: To report the frequency, location, and severity of biomicroscopically evident intrastromal deposits that may accumulate in the lamellar channel after implantation of Intacs corneal ring segments. Setting: United States Food and Drug Administration multicenter clinical trial conducted at 10 sites. Methods: Two‐year follow‐up data from a phase III clinical trial (N = 359) were reviewed. Examiners at 10 study sites described the location and severity (density) of deposits, grading severity on a standardized scale from absent (0) to severe (4). Results: At 24 months, the incidence of deposits was 74% overall and 61%, 73%, and 89% with the 0.25, 0.30, and 0.35 mm Intacs, respectively (P < .001). The incidence increased sharply at first and more slowly after 6 months. At 12 months, deposits were located along the inner curvature of the segments in 47% of patients, along the outer curvature in 5%, along both inner and outer curvatures in 38%, and anterior to the segments in 10%. The severity of the deposits increased with segment thickness (P < .001 at 6, 12, and 24 months). Conclusions: Lamellar channel deposits occurred frequently after Intacs implantation. The incidence and density of deposits increased with segment thickness and duration of implantation. The presence of this material did not result in alteration of the optical performance of Intacs or anatomical or physiological corneal deterioration.

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.

Dynamic corneal imaging

Purpose: To determine the clinical practicability of in vivo dynamic corneal imaging (DCI) to assess the individual elastic properties of normal human eyes, eyes with abnormal findings, and eyes after refractive surgery. Setting: University Eye Clinic, Paracelsus Private Medical University, Salzburg, Austria. Methods: The DCI method uses sagittal, stepwise, central indentation of the cornea with electronically controlled microprecision motors and sequential registration of videotopography images. The indentation steps are preselected and range from 50 to 800 μm. The computerized analysis of the videotopography images captured during the process uses Zernike polynomials to establish a newly defined flexing curve for normal eyes and eyes with abnormal findings. Results: Dynamic corneal imaging was done in 187 eyes of 103 patients who had clinically healthy corneas, distinct keratoconus, or previous refractive surgery. The method rapidly evaluated artificially and reversibly induced changes in corneal topography in a clinical setting using a modified Placido disk–based computer‐assisted videokeratography system with a small cone. In early analysis, the flexing curve showed a significant correlation with the applied indentation depth. Factors influencing the shape of the curve were central corneal thickness, intraocular pressure, and patient age. The DCI method also allowed easy examination of keratoconic corneas and corneas after refractive surgery. Conclusions: Dynamic corneal imaging induced a reproducible and reversible change in corneal topography corresponding to the different indentation depths. The results indicate that several clinical parameters are correlated with corneal elastic behavior in vivo and that the technology could increase the predictability of refractive corneal surgery and help in the early diagnosis of corneal diseases and with newly developed therapies.

Femtosecond laser–assisted intrastromal arcuate keratotomy to reduce corneal astigmatism

Purpose To report the initial results of intrastromal arcuate keratotomy performed with a femtosecond laser to treat corneal astigmatism. Setting Department of Ophthalmology, Paracelsus Medical University, Salzburg, Austria. Design Interventional case series. Methods Patients with corneal astigmatism (naturally occurring or after cataract surgery) were treated with an iFS femtosecond laser to perform paired arcuate cuts on the steep axis completely placed within the corneal stroma. Patients were followed for 6 months after surgery. Preoperative and postoperative (1‐day, 1‐week, and 1‐, 3‐, and 6‐month) examinations included corrected and uncorrected visual acuities, manifest refraction, corneal topography, endothelial cell count, and corneal pachymetry. A subjective questionnaire was used to evaluate patient satisfaction. Results The study enrolled 16 patients. No perforations occurred, and all incisions were placed at the planned locations. After a 6‐month follow‐up, the mean refractive cylinder was reduced significantly from 1.41 diopters (D) ± 0.66 (SD) to 0.33 ± 0.42 D (P<.001). The mean topographic astigmatism was reduced significantly from 1.50 ± 0.47 D preoperatively to 0.63 ± 0.34 D at 6 months (P=.002). There was excellent refractive and topographic stability over time. The endothelial cell density was unchanged. Patient satisfaction was very high. Conclusion The femtosecond laser allowed the effective creation of precise, purely intrastromal, arcuate incision patterns with an excellent safety profile, rapid recovery, and stability of vision without the known risks associated with incisions that penetrate Bowman membrane. Financial Disclosure Dr. Binder is a paid consultant to Abbott Medical Optics, Inc. Dr. Grabner has received travel grants in the past and has at times served as medical advisor to Abbott Medical Optics, Inc., Santa Ana, California, USA. No other author has a financial or proprietary interest in any material or method mentioned.

Histologic evaluation of corneal stroma in rabbits after intrastromal corneal ring implantation.

Purpose. Previous refractive corneal implants have produced histologic changes characteristic of nonspecific lipid keratopathy. Intacs intrastromal corneal ring segments are polymethylmethacrylate (PMMA) corneal inserts approved for the correction of low myopia by the U.S. Food and Drug Administration. The purpose of this study was to describe histologic changes associated with these corneal implants in rabbit eyes. Methods. Two 150-degree PMMA arc segments, 0.30 mm thick, were surgically implanted through a single radial incision at two-thirds stromal depth in the mid-peripheral cornea of five New Zealand white rabbits. We collected corneas 6 months after implantation that were prepared for light and electron microscopy. We analyzed tissue with oil red O, filipin, and periodic acid–Schiff (PAS) staining. Additional studies with energy-dispersive x-ray analysis and autofluorescent microscopy were conducted. Results. In all samples, we observed new collagen formation with lamellar organization adjacent to the implant and increased keratocyte density. Intracellular accumulations of osmophilic and saturated lipid material corresponded to stromal opacification visible by slit-lamp microscopy. These same regions were autofluorescent and stained positively with oil red O, and filipin but negatively with PAS. Granular lipid inclusions characteristic of lipofuscinosis were absent on transmission electron microscopy. Energy-dispersive x-ray analysis demonstrated elevated levels of calcium compared with adjacent tissue. Conclusion. Tissue response to these corneal inserts includes keratocyte activation, intracellular lipid accumulation, and new collagen formation. Our histologic findings suggest that these deposit formations are not lipofuscin accumulations.

Diode laser transscleral cyclophotocoagulation for refractory glaucoma.

PurposeTo evaluate the efficacy of contact diode laser transscleral cyclophotocoagulation using different treatment parameters. MethodsAll eyes undergoing contact diode laser transscleral cyclophotocoagulation between April 1991 and September 1997 at our two institutions were enrolled. Success was defined as an intraocular pressure less than or equal to 22 mm Hg or absence of pain for poorly sighted and blind eyes. ResultsTwo hundred six eyes of 204 patients (Salzburg, 117 eyes; New York, 89 eyes) were enrolled. Mean patient age was 65.8 ± 18.7 years (range, 4–96 years). Mean follow-up was 9.2 ± 11.2 months (range, 3–56 months). Mean preoperative and postoperative IOPs were 42.1 ± 11.0 mm Hg (range, 24–76 mm Hg) and 17.3 ± 10.9 mm Hg (P < 0.001) and 20.3 ± 13.2 mm Hg (P <0.001) at 12 and 24 months, respectively. The number of laser applications (mean, 18.6 ± 4.2; range, 10–40) and maximal laser power (mean, 2,352 ± 408.5 mW; range, 1,500–3,000) were not associated with a lower postoperative IOP. An IOP less than or equal to 22 mm Hg was achieved in 72.7% of eyes at the mean follow-up of 9 months. Thirty-three (16.0%) eyes required at least one retreatment. Phthisis occurred in four (1.9%) eyes. ConclusionContact diode laser transscleral cyclophotocoagulation is useful in eyes with refractory glaucoma in which the risks of outflow surgery are deemed unacceptable.

Reading performance and patient satisfaction after corneal inlay implantation for presbyopia correction: Two-year follow-up

PURPOSE: To evaluate change in reading performance parameters after monocular Kamra corneal inlay implantation for the surgical correction of presbyopia. SETTING: University surgical outpatient center. DESIGN: Prospective interventional case series. METHODS: A corneal inlay was implanted in the nondominant eye. Naturally emmetropic and presbyopic patients between 45 years and 60 years old with an uncorrected distance visual acuity of at least 20/20 in both eyes without additional ocular pathology were eligible for inclusion. Bilateral uncorrected reading acuity, reading distance, mean and maximum reading speed, and the smallest log‐scaled print size (lower case letter of a Radner reading chart) were evaluated using the Salzburg Reading Desk. The minimum postoperative follow‐up was 24 months. RESULTS: Twenty‐four patients were enrolled. The mean reading distance was 46.7 cm ± 6.3 (SD) preoperatively and 39.5 ± 6.4 cm 24 months postoperatively (P<.001). The mean reading acuity at best distance improved (0.33 ± 0.13 logRAD versus 0.23 ± 0.11 logRAD) (P=.004). The mean reading speed increased from 141 ± 20 words per minute (wpm) to 146 ± 20 wpm, respectively (P=.261), and the mean maximum reading speed from 171 ± 28 wpm to 180 ± 22 wpm, respectively (P=.110). The smallest print size improved from 1.50 ± 0.42 mm to 1.01 ± 0.22 mm, respectively (P<.001). CONCLUSION: Improving the depth of focus by monocular implantation of a small‐aperture optic caused statistically significant changes in all tested reading performance parameters except reading speed metrics in emmetropic presbyopic patients. Financial Disclosure: AcuFocus, Inc., Irvine, California, USA, financially supports the Fuchs‐Foundation for the Promotion of Ophthalmology as the clinical research center of the Department of Ophthalmology, Paracelsus Medical University, Salzburg, Austria. Drs. Dexl and Grabner are among the patent owners of the Salzburg Reading Desk technology. Dr. Grabner received travel expenses from AcuFocus, Inc. Dr. Riha currently works as a surgical advisor to AcuFocus, Inc. Drs. Seyeddain, Rückl, Bachernegg, Emesz, and Ruckhofer have no financial or proprietary interest in any material or method mentioned.

Histopathology of human corneas after amniotic membrane and limbal stem cell transplantation for severe chemical burn

Purpose. To describe the histopathologic changes in the cornea following amniotic membrane transplantation (AMT) combined with limbal transplantation. Methods. Four eyes with complete limbal stem cell deficiency after severe chemical burn underwent AMT with either a living-related conjunctival limbal allograft (lr-CLAL) (three eyes) or a conjunctival limbal autograft (CLAU) (one eye) for ocular surface reconstruction. Penetrating keratoplasty was performed several months after the initial procedure for further visual rehabilitation. Mean follow up time was 20 months. Light and transmission electron microscopy (TEM) and indirect immunofluorescence microscopy of the excised corneal buttons were performed. Results. All specimens displayed a multilayered epithelium without conjunctival goblet cells over the entire corneal surface. Basal epithelial cells demonstrated a firm connection to the remnants of the transplanted amniotic membrane (AM), which at some places appeared to be in a state of “modification” or “remodeling” in the collagen layers. The basement membrane zone displayed a positive staining when using antibodies against collagen IV and VII, integrin &agr;6 and &bgr;4, laminin 5, and bullous pemphigoid antigen 2. Remnants of the AM in the specimen showed staining of collagen IV, which was found also in cross-sections of cryopreserved AM. The recipients Bowmans membranes that were only partially present after the initial trauma were significantly disturbed. Conclusion. Within the time frame studied, the transplanted AM apparently survives and integrates into the host tissue being modified or remodeled by recipient cells. AMT in combination with a CLAU or lr-CLAL is a useful technique in promoting a rapid and stable reepithelialization of a corneal surface following severe chemical or thermal damage.