G. Grabner

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.

Standards for Modified Osteoodontokeratoprosthesis (ookp) Surgery According to Strampelli and Falcinelli: The Rome-vienna Protocol

Purpose: To establish a time-proven “gold standard” in modified osteoodontokeratoprosthesis (OOKP) surgery. Methods: The OOKP is the procedure of choice for restoring sight in patients with corneal blindness caused by end-stage ocular surface disease not amenable to penetrating keratoplasty. Members of the OOKP Study Group met in Rome, Italy in 2001 and Vienna, Austria in 2002 to discuss indications and contraindications, patient selection, surgical technique, postoperative care, and recognition and management of complications of OOKP surgery according to Strampelli and modified by Falcinelli. Results: Falcinellis modification of Strampellis technique of OOKP surgery remains the gold standard as far as visual and keratoprosthesis-retention results are concerned. The agreement on indications and contraindications, patient selection, surgical technique, postoperative care, and recognition and management of complications of this technique of OOKP surgery is summarized in the text of this manuscript. Conclusion: This standard technique of modified OOKP surgery, where adequately performed, is capable of providing excellent anatomic and functional results even in the long term. In patients with corneal blindness untreatable by other approaches, we strongly recommend this technique for visual rehabilitation. Students of OOKP surgery should become familiar with the protocol described in this paper before subjecting the technique to further modifications.

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.

Small-aperture corneal inlay for the correction of presbyopia: 3-year follow-up

PURPOSE: To report the 3‐year postoperative safety and efficacy outcomes of the Acufocus corneal inlay. SETTING: University Eye Clinic, Paracelsus Medical University, Salzburg, Austria. DESIGN: Prospective nonrandomized noncomparative cohort study. METHODS: The corneal inlay was implanted in the nondominant eye of naturally emmetropic presbyopic patients. Refraction, uncorrected near (UNVA), intermediate (UIVA), and distance (UDVA) visual acuities; corrected distance visual acuity (CDVA); contrast sensitivity; visual fields; subjective patient satisfaction and symptoms; and operative and postoperative adverse events and complications were evaluated. RESULTS: The study enrolled 32 patients. The mean UNVA improved from Jaeger (J) 6 preoperatively to J1 at 3 years and the mean UIVA, from 20/40 to 20/25, respectively. At 3 years, 97% of eyes had a UNVA of J3 or better and 91% had a UIVA of 20/32 or better. The mean UDVA was 20/20, with all eyes achieving 20/32 or better. Nine eyes (28.3%) lost 1 line of CDVA, 1 eye (3.1%) lost more than 2 lines (3.8 lines), and 3 eyes (9.3%) gained 1 line. No inlay was explanted, and no inflammatory reactions were observed. At 3 years, 15.6% of patients reported severe night‐vision problems and 6.3% (versus 87.5% preoperatively) reported being dependent on reading glasses. CONCLUSIONS: These 3‐year results support the safety and efficacy of the corneal inlay to correct presbyopia in naturally emmetropic presbyopic patients. However, despite a significant gain in UNVA and UIVA, 28.3% of patients lost 1 line of CDVA. Financial Disclosure: Acufocus, Inc., California, USA, financially supports the Research Foundation for Promoting Opthhalmology, Salzburg, Austria, as the clinical research center of the University Eye Clinic, Paracelsus Medical University, Salzburg. Dr. Grabner received travel expenses from Acufocus, Inc. Dr. Riha currently works as a clinical application specialist for Acufocus, Inc. Drs. Seyeddain, Hohensinn, Nix, Rückl, and Dexl have no financial or proprietary interest in any material or method mentioned.

Vitreoretinal morphology of plasmin-treated human eyes

PURPOSE To investigate the ultrastructure of the vitreoretinal interface following an intravitreal injection of plasmin. METHODS Plasmin (2 U/0.1 ml) was injected into the vitreous cavity of five postmortem human eyes. The five fellow eyes received phosphate-buffered saline and served as controls. After incubation at 37 degrees C for 30 minutes, the globes were placed in fixative and hemisected. Specimens for scanning and transmission electron microscopy were obtained using a corneal trephine. RESULTS All plasmin-treated eyes showed complete vitreoretinal separation with sparse collagen fibrils covering the inner limiting membrane. All control eyes showed an attached cortical vitreous. At the vitreous base, there was no cleaving effect. The retinal morphology of plasmin-treated eyes was unchanged. CONCLUSIONS Plasmin induces a cleavage between the vitreous cortex and the inner limiting membrane without morphologic alteration of the retina.

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.

Reading performance after implantation of a small-aperture corneal inlay for the surgical correction of presbyopia: Two-year follow-up

PURPOSE: To evaluate the change in reading‐performance parameters after implantation of the Kamra small‐aperture intracorneal inlay over a 2‐year follow‐up. SETTING: University Eye Clinic, Paracelsus Medical University, Salzburg, Austria. DESIGN: Cohort study. METHODS: This study comprised naturally emmetropic presbyopic patients. Bilateral reading acuity, reading distance, reading speed, and the smallest log‐scaled sentence were evaluated in a standardized testing procedure using the Salzburg Reading Desk. The minimum postoperative follow‐up was 24 months. RESULTS: The study enrolled 32 patients. The reading desk results showed a significant improvement in each parameter tested. After a mean follow‐up of 24.2 months ± 0.8 (SD), the mean reading distance changed from the preoperative value of 48.1 ± 5.5 cm to 38.9 ± 6.3 cm (P < .0001), the mean reading acuity at best distance improved from 0.3 ± 0.14 logRAD to 0.24 ± 0.11 logRAD (P < .000001), and the mean reading speed increased from 142 ± 13 words per minute (wpm) to 149 ± 17 wpm (P=.029). One patient lost 1 line, and 1 patient had no change. The improvement was up to 6 log‐scaled lines (mean improvement 2.7 ± 1.6 lines) in the other 30 patients. CONCLUSIONS: After implantation of the small‐aperture intracorneal inlay, there was an improvement in all tested reading performance parameters in emmetropic presbyopic patients; the improvement was the result of an increased depth of field. These 2‐year results indicate that the inlay is an effective treatment for presbyopia. Financial Disclosure: Drs. Seyeddain, Riha, Hohensinn, and Hitzl have no financial or proprietary interest in any material or method mentioned. Additional disclosures are found in the footnotes.

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.

Measurement of stray light and glare: comparison of Nyktotest, Mesotest, stray light meter, and computer implemented stray light meter

Aim: To evaluate the properties of devices for measuring stray light and glare: the Nyktotest, Mesotest, “conventional” stray light meter and a new, computer implemented version of the stray light meter. Methods: 112 subjects, divided in three groups: (1) young subjects without any eye disease; (2) elderly subjects without any eye disease, and (3) subjects with (early) cataract in at least one eye. All subjects underwent a battery of glare and stray light tests, measurement of visual acuity, contrast sensitivity, refraction, and LOCS III cataract classification. Subjects answered a questionnaire on perceived disability during driving. Results: Repeatability values were similar for all glare/stray light tests. Validity (correlation with LOCS III and questionnaire scores), discriminative ability (ability to discriminate between the three groups), and added value (to measurement of visual acuity and contrast sensitivity) were all superior for both stray light meters. Results of successive measurements are interrelated for the conventional but not the new stray light meter. This indicates a better resistance to fraud for the latter device. Conclusions: The new computer implemented stray light meter is the most promising device for future stray light measurements.