Matthias Bramkamp

Influence of Axial Length on Thickness Measurements Using Spectral-Domain Optical Coherence Tomography

PURPOSE The purpose of this study was to assess the influence of axial length on spectral-domain optical coherence tomography (SD-OCT) thickness measurements in patients with subretinal visual implants. METHODS Data from eight emmetropic pseudophakic eyes of eight patients with subretinal visual implants were analyzed retrospectively. These patients participated in the monocentric part of a multicenter trial. The axial length was measured in three short (<22.5 mm), three medium (22.51-25.50 mm), and two long (>25.52 mm) eyes. Using Heidelberg Spectralis, the known thickness of a subretinal implant microchip (70 μm) was measured on 15 images per eye with SD-OCT, using the software calipers. RESULTS The mean axial length was 20.8 ± 0.8 mm in short eyes, 23.3 ± 0.4 mm in medium eyes, and 26.3 ± 0.5 mm in long eyes. We found in short eyes, in medium eyes, and in long eyes a mean value of microchip thickness measurements from SD-OCT of 82.9 ± 1.4 μm, 70.5 ± 1.3 μm, and 64.2 ± 1.3 μm, respectively. The thickness measurements decreased in SD-OCT measurements with longer axial lengths significantly (P < 0.0001). CONCLUSIONS Axial length influences SD-OCT thickness measurements. Our findings demonstrate accuracy of the scaling in SD-OCT thickness measurements in emmetropic medium eyes. Caution is recommended when comparing the measured values of short and long eyes with the normative database of the instrument. There is a need for larger sample-size studies to confirm our results. (ClinicalTrials.gov number, NCT01024803.).

Reduktion der postoperativen Endophthalmitisrate durch intrakamerale Cerfuroximgabe: Ergebnisse aus 5 Jahren Erfahrungen an der Universitäts-Augenklinik Tübingen

BACKGROUND Cataract surgery is the most commonly performed surgical procedure in developed countries. The annual number of cataract surgeries in Germany is about 600,000. Acute postoperative endophthalmitis is a very severe and the most dreaded complication of cataract surgery. Various operative and non-operative measures have been suggested to prevent this serious complication. The European Society of Cataract & Refractive Surgeons (ESCRS) study of intracameral cefuroxime was the first prospective, randomised and partially placebo-controlled clinical trial showing the efficacy of antibiotic prophylaxis to prevent endophthalmitis in 2007. The aim of this retrospective study is to investigate a possible reduction of intracameral cefuroxime to prevent postoperative endophthalmitis at the University Eye Hospital Tübingen. PATIENTS AND METHODS During the period from January 2002 to August 2013, 2 time periods were determined based on the adoption of intracameral cefuroxime injections after cataract surgery. From January 2002 to May 2009 patients received at the end of cataract surgery a subconjunctival administration of 50 mg of mezlocillin and postoperative antibiotic eye drops (gentamicin) without intracameral injection. From June 2009 to August 2013, patients received an intracameral injection of cefuroxime while antibiotic drops (moxifloxacin) were used too. The rates of postoperative infectious endophthalmitis during these 2 periods were calculated. RESULTS 31 cases of endophthalmitis occurred in 31,386 cataract surgeries. The overall cumulative incidence was 0.99 per 1000 patients. The incidence in the first period without intracameral cefuroxime injection was 1.38 (95 % confidence interval [CI]: 1.03-1.72) per 1000 patients and in the second period 0.44 (95 % CI: 0.34-0.54) per 1000 patients (p < 0.001). CONCLUSION Intracameral injection of cefuroxime reduces the rate of postoperative infectious endophthalmitis in cataract surgery significantly.

The Evolution of Corneal Transplantation

Background The aim of this study was to investigate the evolution of surgical methods in and leading indications for corneal transplantation from 2005 to 2016. Material/Methods Data from the corneal graft waiting list and from all keratoplasties carried out between 2005 and 2016 at the University Eye Hospital Tübingen were retrospectively evaluated. Results A total of 1259 keratoplasties were performed between 2005 and 2016 at the University Eye Hospital Tübingen. The most common surgical indications for corneal transplantation were Fuchs endothelial corneal dystrophy (45.5%) and keratoconus (14.2%). The mean rate of corneal transplantations almost doubled from 71 keratoplasties per year in the first 6-year period to 139 keratoplasties per year in the second 6-year period (P=0.005). The number of penetrating keratoplasties remained similar. The number of Descemet membrane endothelial keratoplasties (DMEK) increased significantly from 2008 to 2016 (P<0.0001). One DMEK procedure was performed in 2008 (representing 1.4% of all transplantations), while 75 DMEK procedures were performed in 2016 (representing 60.5% of all transplantations) (P<0.0001). DMEK became the favored surgical method for endothelial disorders, exceeding penetrating keratoplasty in 2013. Conclusions Our study shows evolutionary changes in preferred corneal transplantation techniques and leading indications for keratoplasty from 2005 to 2016. Since its introduction a decade ago, DMEK is currently the golden standard in the management of corneal endothelial dysfunction.

Commentary for Letter to the Editor on Anterior Chamber Antibiotic Treatment

Die Autoren der Studie [1] bedanken sich für die weiterführende Diskussion zu diesem wichtigen Thema. Die Reduktion des Infektionsrisikos zwischen dem Zeitintervall A und Zeitintervall B liegt unserer Ansicht nach in erster Linie an der Applikationsform der Antibiose am Ende der Kataraktoperation. Die intrakamerale Gabe des Cefuroxims im Gegensatz zur subkonjunktivalen Gabe von Mezlocillin scheint effektiver. Es gab keine wesentlichen Unterschiede am Setting oder den Operationstechniken in den beiden Zeitintervallen. Außerdem spricht die hohe Fallzahl, welche an einer Klinik erhoben wurde, (31386 Kataraktoperationen) für sich. Die 2015 erschienene Metaanalyse von Kessel et al. untermauert unsere Ergebnisse und zeigt eine prophylaktische Wirkung der intrakameralen Antibiotikagabe. In Übereinstimmung zu unseren Ergebnissen wurde festgestellt, dass die intrakamerale Antibiotikaapplikation die Endophthalmitisrate signifikant reduziert [2].