[Reliability of corneal tomography after implantation of intracorneal ring segments for keratoconus]. / Reliabilität der Hornhauttomographie nach Implantation von intrakornealen Ringsegmenten bei Keratokonus.

BACKGROUND AND OBJECTIVE: Intracorneal ring segments (ICRS) are believed to stop the progression of keratoconus (KC). This statement on progression, however, requires knowledge about measurement reproducibility. The purpose of this study was to compare the reproducibility of tomographic parameters in eyes with KC after femtosecond laser-assisted implantation of INTACS (fs-INTACS) using two different devices and to determine which is more reliable for the follow-up of these patients. PATIENTS AND METHODS: In this study 19 KC eyes were included and repeatedly examined 5 times with the Scheimpflug topography Pentacam HR and the Casia 2 optical coherence tomography (VA-OCT) devices. Outcome measures included the reproducibility and comparability of measurements between the two devices of (1) keratometric refractive power of the anterior cornea and (2) posterior cornea, (3) maximum keratometric refractive power, (4) central corneal thickness and (5) corneal thickness at the thinnest site. RESULTS: The mean differences (Pentacam minus Casia 2) of (1), (2), (3), (4) and (5) were 0.67 dpt, 0.41 dpt, 3.4 dpt, 1.5 µm and 11.8 µm, respectively. The mean SDs of the 5 repeat measurements for (1), (2), (3), (4) and (5) were 0.20 dpt/0.20 dpt, 0.10 dpt/0.07 dpt, 0.75 dpt/0.5 dpt, 6.5 µm/2.4 µm (p = 0.007) and 7.3 µm/1.9 µm (p = 0.001) for Pentacam and Casia 2, respectively. Cronbach's alpha was better than 0.98 for both devices and all parameters. CONCLUSION: Both Casia 2 and Pentacam enable a reliable assessment of the corneal refractive power in KC after fs-INTACS implantation; however, the reproducibility was significantly better with Casia 2 only for the measurement of corneal thickness. The Pentacam showed significantly higher values for the mean anterior and posterior corneal refractive power and measured significantly thicker at the thinnest point of the cornea compared to Casia 2.

[Work in progress: adaptation of electronic medical records to the requirements of a university eye clinic : Individual extensions of the software "FIDUS" at the Department of Ophthalmology of the Saarland University Medical Center UKS]. / Work in Progress: Anpassung der elektronischen Patientenakte an die Anforderungen einer Universitätsaugenklinik : Individuelle Erweiterungen der Software "FIDUS" an der Klinik für Augenheilkunde am Universitätsklinikum des Saarlandes UKS.

BACKGROUND: The implementation of electronic medical records (EMR) in the Department of Ophthalmology at the Saarland University Medical Center (UKS) in January 2016 was a timely response to growing documentation requirements and rapidly increasing electronic diagnostic data. The software system was primarily developed for private practices and cannot therefore meet the different requirements of various clinics out of the box. The purpose of this study was to identify features of the EMR beyond purely paper replacement that can assist in the clinical workflow and whether these features can be implemented in a running system. METHODS: The EMR was specifically individualized with respect to the work processes and documentation requirements of the Department of Ophthalmology at the UKS. In addition to a seamless integration into the hospital information system (HIS) the modifications included changes in the structure and visual presentation of the EMR as well as functional extensions. An internet-based platform was set up to enable a direct exchange of appointments and patient data with specialist practices. RESULTS: Due to the introduction of a so-called ghost list the position of patients within the hospital who are allocated to a physician, e.g. for diagnostics, can be reconstructed at any point in time. The logging of the individual treatment times enables tracking of patient flow within the clinic and a reduction of waiting times. Existing paper documents particularly for the graphic recording of findings, such as sketches, are digitalized eliminating the need to scan documents. The UKS.AUGEN.NETZ is an internet-based portal to facilitate direct organization of appointments with specialist practitioners and for the exchange of digital examination data and medical correspondence. CONCLUSION: The permanent close cooperation between employees of the Department of Ophthalmology at the UKS and the manufacturer of the software enables a continuous optimization of the EMR in a fully operational clinical workflow. In addition, the web-based interface improves the cooperation between the hospital and private practices.

Asymmetry between Left and Right Eyes in Keratoconus Patients Increases with the Severity of the Worse Eye.

PURPOSE: To evaluate whether the inter-eye asymmetry of keratoconus (KC) patients is different from a healthy control group and to investigate how asymmetry changes with increasing severity of the disease. METHODS: In this retrospective study, we included both eyes of 350 patients with KC (age 35 ± 13 years) and 68 candidates planned for refractive surgery (control group, age 37 ± 11 years). Inclusion criteria for the KC group were keratoconus in at least one eye with Pentacam Topographical Keratoconus Classification (TKC) of at least 0.5. Patients eligible for refractive surgery in both eyes were included in the control group. Corneal tomography as well as Ocular Response Analyzer measurements were compared between both groups. Subgroup analysis was performed with respect to the TKC staging. Asymmetry was provided as worse eye (defined by higher TKC) minus fellow eye. RESULTS: In the KC group, both eyes showed the same TKC staging in 30.6%, a difference of one stage in 34.0% and of two stages in 24.6% of the patients. The inter-eye asymmetry in the keratoconus group was significantly larger than that in the control group. Corneal power showed an asymmetry of 3.8 ± 4.0 D in keratoconus eyes versus 0.22 ± 0.17 D in the control group. Central corneal thickness (CCT) asymmetry was 34 ± 30 µm versus 6 ± 5 µm, respectively. The Keratoconus Match Index showed an asymmetry of 0.40 ± 0.35 versus 0.15 ± 0.14. The difference between both eyes increased with increasing TKC of the worse eye. CONCLUSIONS: Inter-eye asymmetry is larger in keratoconus than in normal eyes, and it increases with keratoconus severity in the worse eye.

[Safety of Hyaluronic Acid in Postoperative Treatment after Penetrating Keratoplasty]. / Verträglichkeit von Hyaluronsäure zur Oberflächenpflege nach perforierender Keratoplastik.

BACKGROUND: The objective of this clinical trial was to confirm the safety of phosphate-free high molecular weight hyaluronate (HYLO®-GEL) as lubricant for postoperative care after penetrating keratoplasty. PATIENTS AND METHODS: 51 eyes were followed up 6 weeks after penetrating keratoplasty under therapy with phosphate-free high molecular weight hyaluronate. Visual acuity, intraocular pressure, conjunctival hyperaemia, conjunctival chemosis, corneal fluorescein staining, corneal infiltrates, corneal endothelial-epithelial decompensation, Descemet's folds, Tyndall effect, cells in the anterior chamber and subjective assessment of lacrimation, foreign body sensation, pressure sensation, burning, mucus and itching were recorded on the first, third and fifth postoperative days and six weeks postoperatively. Tolerance was rated by the patient and the attending ophthalmologist. RESULTS: The following objective parameters improved significantly from day 1 to week 6 in patients treated with phosphate-free high molecular weight hyaluronate: visual acuity, conjunctival hyperaemia, conjunctival chemosis, corneal fluorescein-staining, corneal endothelial-epithelial decompensation, Descemet's folds, the maximum diameter of corneal erosion, Tyndall effect and cells in the anterior chamber. In addition, there was significant improvement in the course of the following subjective complaints: lacrimation, foreign body sensation, pressure sensation and itching. In total 63 % (32/47) of the study patients reported excellent local tolerance of phosphate-free high molecular weight hyaluronate on day one postoperatively. This proportion rose to 86 % (37/43) 6 weeks postoperatively. The safety of phosphate-free high molecular weight hyaluronate was rated by the ophthalmologists as "perfect" in 92 %, as "acceptable" in 6 % and as "unacceptable" in 2 % of eyes. CONCLUSION: Therapy with phosphate-free high molecular weight hyaluronate results in significant improvements in objective findings and subjective symptoms after penetrating keratoplasty. Tolerance was rated as "excellent" by the ophthalmologist in 92 % of patients in the early postoperative follow-up.

[Per aspera ad astra: implementation of electronic patient records in a university eye hospital : Experience with FIDUS in the Clinic for Ophthalmology at the Saarland University Medical Center UKS]. / Per aspera ad astra: Einführung einer elektronischen Patientenakte an einer Universitätsaugenklinik : Erfahrungen mit "FIDUS" in der Klinik für Augenheilkunde am Universitätsklinikum des Saarlandes UKS.

BACKGROUND: For more than 60 years patient records of the Department of Ophthalmology at the Saarland Medical Center in Homburg were documented on handwritten paper documents and filed in archives. Increasing requirements for medical documentation, exploding volumes of diagnostic data, overcrowded archives and unavailable files when needed, were the essential rationales for the implementation of an electronic patient archive (EPA). METHODS: The EPA has been specifically adapted to the requirements of the Department of Ophthalmology in order to guarantee a standardized unobstructed documentation and patient care across all sections of the department. Seamless integration into the clinic information system (KIS) and network-compatible diagnostic software were essential as well as a timely digitization of existing paper charts. Decisive factors for using FIDUS (Arztservice Wente GmbH, Darmstadt, Germany) as the EPA software were the visual layout of the EPA, user friendliness and reference installations of the software in other ophthalmology departments. RESULTS: After one and a half years of meticulous preparation with specific adaptations to the requirements of our department, the EPA was finally implemented in January 2016 and since then we have been working on improvements. The EPA software retrieves basic patient data from the KIS and diagnostic data from electronic devices via various interfaces. Expenses for printers could be reduced but computer workplaces had to be expanded or newly created. For previous patients paper files are digitized externally and stored in an electronic archive directly accessible from the EPA. DISCUSSION: Successful reorganization and implementation of electronic documentation during clinical routine is feasible with careful preparation and timely involvement of information technology experts, motivated physicians, nurses, research departments and the administration.

[Reproducibility of Scheimpflug Tomography Measurements Regarding Corneal Front and Back Surface Power]. / Reproduzierbarkeit der Messungen der Scheimpflug-Tomografie für die Brechwerte der vorderen und hinteren Hornhautgrenzfläche.

BACKGROUND AND PURPOSE: The Oculus Pentacam® is one of the most commonly used devices in ophthalmology for assessment of the anterior eye segment. The purpose of this study was to determine the reproducibility of the corneal power as measured by the Pentacam® in a normal population. METHODS: We enrolled 25 eyes of 25 subjects aged between 13 and 68 (46.7 ± 21.7) years, within a spherical equivalent from - 4 D to + 4 D and refractive cylinder up to 5 D and without notable pathologies or history of surgery. A sequence of 5 measurements was performed using the Pentacam®, the Zeiss IOLMaster® as well as an autorefractometer after (re-)positioning the patient's head and the measurement device. From the Pentacam® we collected power data for the corneal front and back surfaces, apical corneal thickness at apex and internal anterior chamber depth. From the IOLMaster®, we extracted corneal power data, and from the autorefractometer we obtained refractive power data of both cardinal meridians. For statistical analysis, we used Cronbach's α as a measure of reproducibility and Spearman's rank correlation test for correlation of data. RESULTS: Pentacam® yields highly reproducible power data for both corneal surfaces, with Cronbach's α of greater than 0.97 for primary parameters (e.g. radii of curvature) and 0.9 for secondary parameters (e.g. vector components of astigmatism). Central corneal thickness and eccentricities of both surfaces as well as anterior chamber depth yielded highly reproducible values, with α of ≥ 0.97. Corneal power derived from IOLMaster® and objective refraction extracted from the autorefractometer yielded α values of around 0.9. Mean corneal power of Pentacam® and IOLMaster® correlated well, but there was no correlation to spherical equivalent. Astigmatism values from Pentacam® and IOLMaster® correlated well with each other and with refractive cylinder. CONCLUSION: Our results indicate that measurements of anterior segment using the Pentacam® yield highly reproducible results in a normal population without major pathologies of the anterior eye segment.

[The German Acanthamoeba keratitis register: Initial results of a multicenter study]. / Das Deutsche Akanthamöbenkeratitis-Register : Erste Ergebnisse einer multizentrischen Erhebung.

BACKGROUND AND PURPOSE: In September 2011 the cornea section of the German Ophthalmological Society (DOG) established the first German Acanthamoeba keratitis registry. The data of this multicenter survey are being collected, compiled and evaluated at the Department of Ophthalmology at the Saarland University. The aim of this article is to present an intermediate report. PATIENTS AND METHODS: Data from 172 eyes with Acanthamoeba keratitis were collected during the last 10 years. For this interim report we actually evaluated 121 eyes (60.2 % female patients, average age 41.3 years) and collected the following data: date of onset of symptoms, date and method of diagnosis, initial diagnosis, anamnestic data, clinical symptoms and signs at diagnosis and during follow-up, conservative and surgical therapy. Criteria for inclusion in the Acanthamoeba registry was the established diagnosis of an Acanthamoeba keratitis with at least one of the methods described in this article. RESULTS: Acanthamoeba keratitis could be histologically proven in 55.3 % of the cases, via PCR in 25.6 %, with confocal microscopy in 20.4 % and using in vitro cultivation in 15.5 %. Clinical symptoms and signs in Acanthamoeba keratitis were pain in 67.0 %, ring infiltrates in 53.4 %, pseudodendritiform epitheliopathy in 11.7 % and keratoneuritis in 5.8 %. In 47.6 % of the cases the initial diagnosis was herpes simplex virus keratitis followed by bacterial keratitis in 25.2 % and fungal keratitis in 3.9 %. Acanthamoeba keratitis was the correct initial diagnosis in only 23.2 % of cases. The average time period between first symptoms and diagnosis was 2.8 ± 4.0 months (range 0-23 months). A triple therapy with Brolene® Lavasept® and antibiotic eye drops at least 5 ×/day was used in 54.5 % of eyes (n = 66). Penetrating keratoplasty was performed in 40.4 %, in 18 cases in combination with cryotherapy of the cornea. The mean graft diameter was 7.9 ± 1.1 mm (range 3.5-11.0 mm). The final visual acuity (Snellen visual acuity chart at 5 m) was comparable in the two groups of eyes with (5/40 ± 5/25) and without (5/32 ± 5/25) keratoplasty. CONCLUSION: Acanthamoeba keratitis is a rare and often very late diagnosed disease and two thirds of the cases were initially misdiagnosed. The early recognition of the typical symptoms is crucial for the prognosis of the disease. All ophthalmological departments in Germany are invited to submit further data of all confirmed cases (berthold.seitz@uks.eu), whether retrospectively or prospectively in order to generate an adequate standardized diagnostic and therapeutic approach for this potentially devastating disease.

[Can the implantable collamer lens with AquaPORT technology safely prevent an angle block? Early experiences in the Homburg/Saar refractive surgery center]. / Kann die implantierbare Collamer-Linse mit Aquaport eine Winkelblockproblematik sicher verhindern? Erste Erfahrungen aus dem Homburger Zentrum für refraktive Chirurgie.

INTRODUCTION: The spectrum of surgical correction of high myopia has been broadened through surgical implantation of phakic intraocular lenses (pIOL) as a possible alternative to corneal refractive surgery. The purpose of the present study was to evaluate the intraoperative and early postoperative results of patients after the implantation of a posterior chamber implantable collamer (ICL) pIOL to correct high myopia. In particular the study tried to answer the question whether the AquaPORT technology can safely prevent angle closure glaucoma. PATIENTS AND METHODS: From March 2012 to November 2013, 24 eyes from 12 patients suffering from a high myopia (-8.75 ± 4.37 D, maximum -22.75 D) underwent implantation of a posterior chamber implantable phakic collamer intraocular lens (ICL) with AquaPORT technology in the Homburg/Saar refractive surgery center. The implantable ICL consists of collamer, a collagen copolymer (Staar surgical-V4b/c). RESULTS: The mean age of the patients was 35.5 ± 1.35 years. At 12 months follow-up mean uncorrected distance visual acuity improved among the patients from 0.013 ± 0.04 preoperatively to 0.8 ± 0.45 postoperatively and the best corrected visual acuity from 0.8 ± 0.16 to 0.8 ± 0.3. Mean spherical equivalent decreased from -9.00 ± 4.68 D preoperatively to 0.12 ± 1.94 D postoperatively. A statistically significant difference in the intraocular pressure (IOP) was not observed (p = 0.3). The central distance between the posterior surface of the lens and the anterior surface of the pIOL (vault) was 0.45 ± 0.49 mm (minimum 0.064 mm, maximum 3.706 mm). Despite the AquaPORT a 28-year-old white woman suffered from a high postoperative IOP of 42 mmHg in both eyes and an ICL with diameter of 12.6 mm was substituted by an ICL with diameter 13.2 mm without complications. CONCLUSION: The implantation of an ICL with AquaPORT technology provides a reliable alternative with good postoperative visual quality to all patients with high myopia when corneal refractive surgery is not possible. In order to enable early detection and treatment of increases in IOP due to angle block, regular postoperative IOP measurements are recommended.

[Interobserver and intraobserver reliability of corneal surface temperature measurements with the TG-1000 thermograph in normal eyes]. / Inter- und Intraobserverreliabilität der kornealen Oberflächentemperaturmessung mit dem TG-1000 bei Normalaugen.

PURPOSE: The aim of this study was to analyze the reliability of temperature measurements with the ocular TG-1000 thermograph in a setup of sequential measurements performed by one observer (intraobserver) and a sequence of measurements performed by different observers (interobserver) in normal subjects without pathologies of the anterior segment of the eye. PATIENTS AND METHODS: A total of 50 right eyes from 50 individuals (mean age 29.1 ± 7.9 years) without ocular pathologies or history of ocular surgery were enrolled in this prospective monocentric clinical case series. Eyes with signs of dry eye syndrome (based on a positive McMonnies questionnaire) were excluded from the study. Corneal surface temperature measurements were performed by three examiners to assess interobserver reliability. In addition, in a subgroup of 22 individuals, a sequence of 3 measurements were performed by 1 of the examiners to examine intraobserver reliability. Corneal surface temperature was measured within an interval of 10 s (11 frames) on a region of interest of 16 ± 12 mm (320 ± 240 pixels). Central and mid-peripheral local temperatures at 3 mm (3, 6, 9 and 12 o'clock) were extracted and analyzed from the raw data. RESULTS: The ocular TG-1000 thermograph yielded consistent results for the interobserver as well as intraobserver conditions in measuring corneal surface temperature in the center as well as mid-periphery of the cornea. Cronbach's alpha was 0.9 or higher at all corneal locations, which proves a high consistency of results for the interobserver and intraobserver measurements. The average corneal surface temperature ranged between 34.0 °C and 34.7 °C with a slight decrease from the upper temporal (9 and 12 o'clock) to the lower nasal (3 and 6 o'clock) quadrants. CONCLUSION: The TG-1000 thermograph yielded consistent results of corneal surface temperature in individuals without anterior segment pathologies or history of ocular surgery. With the option of raw data export (11 frames within 10 s with a lateral resolution of 320 × 240 pixels) the thermograph offers a wide range of new diagnostic options for a spatiotemporal analysis of corneal surface temperature.

[Comparison of the specificity and sensitivity of various instrument-guided keratoconus indices and classifiers]. / Vergleich der Spezifität und Sensitivität verschiedener gerätegestützter Keratokonusindizes und -klassifikatoren.

PURPOSE: Are the classifications achieved by the Belin-Ambrósio (BA) enhanced ectasia module, the keratoconus indices of the Pentacam HR and the ectasia screening index (ESI) using CASIA anterior segment optical coherence tomography (OCT) comparable to the topographical keratoconus classification (TKC) of the Pentacam HR? Can the indices be used interchangeably to assist in the diagnosis of keratoconus? METHODS: This retrospective study examined 228 datasets (eyes) of patients with a mean age of 36.6 ± 13.6 years which were grouped into a non-keratoconus group (group I, n = 59) and a keratoconus group (group II, n = 169) according to the clinical assessment. From the data sets of these eyes the sensitivity and specificity of various ectasia and keratoconus indices (KI) were calculated with the help of receiver operating characteristics (ROC). Groups were compared using the Mann-Whitney and χ(2)-tests. RESULTS: Groups I and II had a mean KI of 1.04 and 1.26 and a mean ESI of 3.0 and 66.6, respectively. The χ(2)-test showed no significant coincidence of the distance of the thinnest point from the apex with TKC (χ(2) > 2, p > 0.35). All other BA parameters as well as the ESI showed a significant coincidence with the keratoconus diagnosis and the classification of TKC (p < 0.001). The ESI and KI along with some BA parameters (Df, Db, Dp and D) showed a good separation between groups I and II with an area under the ROC curves of > 0.93. CONCLUSION: The enhanced indices and classifiers, such as the BA module or the ESI were comparable with the purely anterior corneal surface based TKC.

[Retroiridal implantation of a Verisyse™ iris claw lens: refractive outcome and individualized intraocular lens constants]. / Retroiridale Implantation einer Verisyse(TM) Irisklauenlinse : Refraktive Treffsicherheit und Anpassung der Kunstlinsenkonstanten.

BACKGROUND: Evaluation of refractive predictability with retroiridal implantation of a Verisyse(TM) iris-claw lens (AMO) and optimization of the IOL-constants recommended by the manufacturer. PATIENTS AND METHODS: A retrospective study after retroiridal iris-claw lens implantation in the years 2007-2012 including 52 eyes of 50 patients with a lack of capsular support was carried out. Follow-up data was recorded on average 5 weeks after surgery. Demographic data, indications, accompanying diseases, biometrical data and refractive outcome were analysed and an individualization of the intraocular lens constants for the SRK/T-, Holladay-1, Hoffer-Q and Haigis-formula was carried out. RESULT: Indications for retroiridal implantation of a Verisyse(TM) lens were IOL luxation (32.7 %), complicated primary cataract surgery (25.0 %), secondary IOL Implantation (19.2 %), lens exchange (19.2 %) and luxation of the crystalline lens (3.8 %). Accompanying diseases were pancreatic diabetes (21.2 %), rheumatic diseases (7.7 %), homocystinuria (1.9 %), pseudoexfoliation of lens capsule (23.1 %), traumata (23.1 %), secondary glaucoma (23.1 %), proliferative diabetic retinopathy (9.6 %) and age related macular degeneration (5.8 %). Optimized IOL constants were an A-constant of 116.8 for the SRK/T formula, a surgeon factor (Holladay1) of 0.8, a pACD (HofferQ) of 4,4 and an a0 constant of 0,49 for the Haigis formula. Postoperative deviation of target refraction was within ± 2 D in 84.6 % of the eyes. CONCLUSION: The retroiridal Verisyse(TM) intraocular lens shows a broad spectrum of indications and achieves a good visual outcome. The previously published IOL constants show optimization potential due to the small number of cases.

[Protective glasses. Personal eye protection for professional use]. / Schutzbrille. Persönlicher Augenschutz für den beruflichen Einsatz.

Several activities in the occupational environment or in leisure time implicate an increased risk of eye injuries. Many injuries could be prevented by wearing adequate eye protection devices; however, the selection of appropriate eye protection devices requires considerations of different attributes in order to achieve a maximum of protection efficiency. This article provides an overview on the three basic types of eye protection device, introduces the classification regarding optical and protective properties and gives some additional advice on the selection of protective eyewear beyond the current standard regulations.

[A comparison of device-based diagnostic methods for keratoconus]. / Gerätegestützte Diagnostikverfahren des Keratokonus im Vergleich.

PURPOSE: Due to the modern device-assisted diagnosis of keratoconus by topography, tomography and biomechanical properties of the cornea, a large number of parameters and indices are obtained as a result of clinical examinations. The aim of the present study was to investigate how modern screening methods support the diagnosis of keratoconus. PATIENTS AND METHODS: In this prospective study, 93 eyes of 93 keratoconus patients and 107 eyes of 107 healthy subjects (control group) were included. The keratoconus group contained 85 % males, whereas the distribution in the control group was balanced. The mean age was 35 ± 12 years in the keratoconus group and 27 ± 7 years in the control group. Exclusion criteria for both groups were previous eye surgery, cross-linking therapy, glaucoma, uveitis or other inflammatory diseases of the eye. All patients with a thyroid disorder were also excluded from the control group. All eyes were examined using the TMS-5 topographer, Pentacam and Ocular Response Analyzer (ORA). Based on receiver operator characteristics (ROC), the performance of various keratoconus indices was determined by means of the area under the curve (AUC). RESULTS: All parameters showed statistically highly significant differences between the keratoconus and control group (p ≤ 0.0001). The Surface Asymmetry Index (SAI) and the Keratoconus Severity Index (KSI) of TMS performed well with (mean value keratoconus group/mean value control group/AUC) SAI (2.43/0.36/0.969) and KSI (50.87/0.37/0.912). Pentacam parameters Index of Surface Variance (ISV) and Topographic Keratoconus Classification (TKC) were comparable to TMS parameters with ISV (90.05/15.77/0.969), TKC (2.23/0.00/0.940). ORA indices Corneal Hysteresis (CH), Corneal Resistance Factor (CRF) and Keratoconus Match Index (KMI) showed slightly poorer performance with CH (8.22/11.48/0.909), CRF (7.25/11.20/0.951), KMI (0.31/1.05/0.909). CONCLUSION: In this study, tomography and topography was more reliable in diagnosing keratoconus than evaluating the biomechanical properties of the cornea. SAI and KSI (TMS) as well as TKC and ISV (Pentacam) showed improved recognition rates compared to the KMI (ORA). However, individual parameters alone are not sufficient for the diagnosis of keratoconus.

[Intacsintracorneal ring segments in keratoconus]. / Intrakorneale Ringsegmente beim Keratokonus.

INTRODUCTION: The spectrum of stage-related therapy of keratoconus has been broadened through surgical implantation of intracorneal ring segments (INTACS) as a possible method of reducing irregular astigmatism, leading to a reduction of corneal grafts especially in young, working-aged patients with keratoconus. The purpose of the present study was to evaluate the preoperative and postoperative results of femtosecond laser-assisted implantation of INTACS in ectatic corneal diseases. PATIENTS AND METHODS: From August 2011 to January 2013, 20 eyes from 16 patients with a clear cornea in the visual axis suffering from hard contact lens intolerance underwent surgery in the Homburg/Saar Keratoconus Center (HKC) by the same surgeon (MEH). Among these were 16 keratoconus eyes, 1 eye with pellucid marginal degeneration und 3 eyes with post-LASIK iatrogenic keratectasia. The insertion of the INTACS ring segments was achieved by a femtosecond laser-assisted procedure that created a precise 360° tunnel at a depth of 80% of the corneal thickness (395.8 ± 38.5 µm) in the 6­7 mm zone.Results. At 6 months follow-up mean uncorrected distance visual acuity improved from 0.07 ± 0.07 preoperatively to 0.6 ± 0.26 postoperatively. Mean best-corrected distance visual acuity changed from 0.4 ± 0.15 preoperatively to 0.9 ± 0.29 postoperatively. Mean sphere decreased from −7.6 ± 6.1 dpt to −1.4 ± 2.8 dpt. Astigmatism decreased from −6.0 ± 2.8 dpt preoperatively to −4.3 ± 2.0 dpt postoperatively. There was also a reduction in the mean flat K from 47.8 ± 4.7 dpt preoperatively to 44.2 ± 5.0 dpt postoperatively and in mean steep K from 51.9 ± 5.0 dpt to 48.4 ± 6.6 dpt. The central eccentricity index in the Pentacam was reduced to around 50%. Neither intraoperative nor postoperative complications (including non-responders) were observed. CONCLUSIONS: The femtosecond laser-assisted INTACS implantation provides a valid alternative to early keratoplasty for keratoconus patients with a clear central cornea and contact lens intolerance. It is a minimally invasive and reliable method for stage-related surgical management of keratoconus.

[Detection of early forms of keratoconus - current screening methods]. / Früherkennung des Keratokonus - systemassistierte Screening-Verfahren heute.

The detection of early forms of keratoconus is still a challenge for clinicians. Beside clinical examination and diagnosis of keratoconus, a series of examination techniques has been established in clinical routine to assist in the diagnosis of early forms of keratoconus: corneal topography for measuring the geometry of the corneal front surface, tomography for measuring the geometry of structures of the anterior segment of the eye, aberrometers for evaluation of optical aberrations of the entire eye, and a system for investigation of the biomechanical properties of the cornea. These instruments provide software tools which are designed for diagnostic support in keratoconus. In this review article, we provide an overview over the spectrum of measurement systems currently on the market focussing on their performance for detecting (early forms of) keratoconus. In detail, we focus on dedicated keratoconus screening software modules of topography, tomography, aberrometry and biomechanics.

Theoretical model for design and analysis of protectional eyewear.

INTRODUCTION: Protectional eyewear has to fulfill both mechanical and optical stress tests. To pass those optical tests the surfaces of safety spectacles have to be optimized to minimize optical aberrations. MATERIAL AND METHODS: Starting with the surface data of three measured safety spectacles, a theoretical spectacle model (four spherical surfaces) is recalculated first and then optimized while keeping the front surface unchanged. Next to spherical power, astigmatic power and prism imbalance we used the wavefront error (five different viewing directions) to simulate the optical performance and to optimize the safety spectacle geometries. RESULTS: All surfaces were spherical (maximum global deviation 'peak-to-valley' between the measured surface and the best-fit sphere: 0.132mm). Except the spherical power of the model Axcont (-0.07m(-1)) all simulated optical performance before optimization was better than the limits defined by standards. The optimization reduced the wavefront error by 1% to 0.150 λ (Windor/Infield), by 63% to 0.194 λ (Axcont/Bolle) and by 55% to 0.199 λ (2720/3M) without dropping below the measured thickness. CONCLUSION: The simulated optical performance of spectacle designs could be improved when using a smart optimization. A good optical design counteracts degradation by parameter variation throughout the manufacturing process.

[Individualization of IOL constants for two hydrophobic intraocular lenses. SRK II, SRK/T, Hoffer-Q, Holladay 1 and Haigis formula]. / Individualisierung der IOL-Konstanten für 2 hydrophobe Intraokularlinsen. SRK II, SRK/T, Hoffer Q, Holladay 1 und Haigis-Formel.

AIM: The aim of the study was an assessment of refraction error after implantation of two types of hydrophobic acrylic intraocular lenses and derivation of customized IOL constants for the SRK II, SRK/T, Hoffer Q, Holladay 1 and Haigis formula. PURPOSE: The purpose of the present study was to analyze the refractive outcome of two hydrophobic acrylic intraocular lenses and to present a computerized calculation scheme for customization of lens-specific parameters provided by the lens manufacturers based on the refractive results of a surgeon or study center. METHODS: In this prospective monocentric study 100 consecutive cataract eyes were treated at the Eye Hospital of the Barmherzige Brüder (Compassionate Brothers) in Linz/Austria with a hydrophobic acrylic aspherical intraocular lens (Polytech Y10AS, n = 50) or a hydrophobic acrylic spherical intraocular lens (Hoya PC-60R, n = 50). The biometrical data were assessed preoperatively together with the refractive outcome 8-10 weeks after treatment in order to analyze the deviation of postoperative refraction (spherical equivalent) from target refraction (ΔREF) and to customize the lens constants for the SRK II, SRK/T, Hoffer Q, Holladay 1 and Haigis formula. RESULTS: Based on this data set it could be demonstrated that using the lens constant provided by the manufacturer (ΔREF) the Polytech lens showed a systematic trend to myopia in contrast to the Hoya lens which ranged around zero. This trend could be compensated by selecting appropriate lens specific constants. For the Polytech/Hoya lens median lens constants of: A = 118.0/118.6 (SRK II), A = 117.9/118.6 (SRK/T), pACD = 4.8/5.1 (Hoffer Q), SF = 1.1/1.5 (Holladay I) and d = 4.2/4.6 (Haigis) were extracted and using linear regression a lens constant triplet for the Haigis formula of a(0) = 4.39, a(1) = 0.29, a(2) = 0.11/a0 = 4.73, a(1) = 0.30, a(2) = -0.01 could be derived. CONCLUSIONS: Ophthalmic surgeons or surgical centers are encouraged to check (refractive) outcomes after cataract surgery permanently in terms of quality control. If a systematic trend in ΔREF could be extracted from the data set a customization of the lens-specific constants is recommended to eliminate systematic errors. Such customization is only valid for a dedicated environment (e.g. for one surgical center with standardized surgical techniques and measurement equipment) and cannot be generalized.

[Investigation of the theoretical image quality of aspheric intraocular lenses by decentration. Hoya AF-1 iMics1 und Zeiss ASPHINA(TM) (Invent ZO)]. / Untersuchung der theoretischen Abbildungsqualität asphärischer Intraokularlinsen bei Dezentrierung. Hoya AF-1 iMics1 und Zeiss ASPHINA(TM) (Invent ZO).

BACKGROUND: The image quality of aberration correcting aspherical intraocular lenses (IOLs) depends on the centration in the eye. Aberration correcting IOLs of the second generation are claimed to be more robust to decentration. In this study the image quality of such IOLs was analyzed with decentration values of up to 1 mm. MATERIALS AND METHODS: In this study two aberration correction IOLs of the second generation were compared in a model eye. The IOLs were decentered for two pupil diameters (3.0 and 4.5 mm) in a range of ± 1 mm relative to the line of sight in 50 µm steps and the modulation transfer function was calculated. The results were compared for different spatial frequencies and visual acuities. RESULTS: The analyzed IOLs are superior to the spherical IOL in a decentration range from -0.45 mm to 0.60 mm (30 CPD, cycles per degree) for both pupil diameters. Especially for the greater pupil diameter the lenses show tolerance of image quality to lens decentration. CONCLUSIONS: Both IOLs show only a slight decrease in image quality with decentration and the range of tolerable decentration is increased compared to aspherical IOLs of the first generation.

[Contact free in-vivo imaging of cornea and anterior chamber of the human eye - a qualitative comparison of imaging techniques]. / Kontaktlose In-vivo-Bildgebung der Hornhaut und Vorderkammer des menschlichen Auges - ein qualitativer Vergleich zweier Bildgebungsmodalitäten in der Praxis.

For the contactless diagnosis of the human cornea and anterior chamber in clinical routine, two systems have been established besides the slit lamp: the Scheimpflug camera and optical coherence tomography (OCT). A short introduction into these imaging methods is provided along with a comparison with respect to imaging quality and the visibility of relevant ocular structures. We present different examples from special clinical diagnostics such as keratoconus, condition after keratoplasty or tumours in ocular tissue.