[Corneal biomechanics before and after cross-linking in patients with keratoconus]. / Die Biomechanik der Hornhaut vor und nach Crosslinking bei Patienten mit Keratokonus.

OBJECTIVE: The aim of this study was to analyze the effect of corneal cross-linking (CXL) on corneal biomechanics and visual acuity. PATIENTS AND METHODS: The examination results before and after CXL in 56 eyes of 56 patients between 2017 and 2021 were evaluated retrospectively. The last preoperative examination was compared to the postoperative follow-up values after 6 and 12 months. The main outcome measures included various biomechanical parameters from the Corvis ST (CST), Pentacam and the visual acuity (logMAR, "logarithm of the Minimal Angle of Resolution"). For longitudinal evaluation, a general linear model for repeated measurements was used. A p-value of less than 0.05 was considered to show a statistically significant result. Bonferroni correction was applied for multiple comparisons. RESULTS: The maximum corneal refractive power Kmax decreased slightly without statistical significance from 57.1 ± 6.1 diopters (dpt) to 56.6 ± 6.3 dpt after 6 months (p = 0.076) and 56.8 ± 6.6 dpt after 12 months (p = 0.443). The Pentacam parameter Belin/Ambrósio Enhanced Ectasia Total Deviation Display (BAD D) showed a statistically significant increase from the preoperative value of 8.4 ± 3.7 to the postoperative value of 9.1 ± 3.6 after 6 months (p < 0.001) and to 8.9 ± 3.5 after 12 months (p = 0.051). The CST parameter Ambrósio's relational thickness to horizontal profile (ARTh) decreased statistically significantly from 229.9 ± 109.6 to 204.8 ± 84.9 at 6 months (p = 0.017) and 205.3 ± 93.7 at 12 months (p = 0.022). The CST parameter stiffness parameter A1 (SP A1) increased slightly from the preoperative value 69.9 ± 17.2 to 70.4 ± 17.2 after 6 months (p = 1) and 71 ± 18.2 after 1 year (p = 1). Mean best-corrected visual acuity (logMAR) showed an improvement from 0.39 ± 0.3 to 0.34 ± 0.3 at 6 months (p = 0.286) and to 0.31 ± 0.3 at 12 months (p = 0.077). Regarding the ABCD classification, the parameters were determined preoperatively with an average of A2B3C1D2. They showed the same value of A2B3C1D2 after 6 and 12 months. CONCLUSION: In progressive keratoconus, corneal cross-linking has the potential to positively influence the biomechanics of the cornea and visual acuity as a low complication treatment option.

[Phototherapeutic keratectomy for epithelial basement membrane dystrophy : Impact of excimer laser systems used on the changes of visual acuity, refraction and astigmatism]. / Phototherapeutische Keratektomie bei Epithel-Basalmembran-Dystrophie : Einfluss verwendeter Excimerlaser-Systeme auf die Entwicklung von Visus, Refraktion und Astigmatismus.

BACKGROUND: Excimer laser-assisted phototherapeutic keratectomy (PTK) has become established as the gold standard in treatment of epithelial basement membrane dystrophy (EBMD), commonly also known as map-dot-fingerprint dystrophy (MDF). At the Department of Ophthalmology, Saarland University Medical Center in Homburg/Saar, systems from Zeiss Meditec and Schwind have been used. The outcomes of both were compared in this study. PATIENTS AND METHODS: The retrospective study included patients who underwent PTK with a diagnosis of MDF between 2007 and 2017. A total of 170 operations were performed using Zeiss Meditec MEL-70 (Carl Zeiss Meditec AG, Jena, Germany) and 98 using a Schwind eye-tech-solutions Amaris 750S laser (Schwind eye-tech-solutions GmbH, Kleinostheim, Germany). Preoperative and postoperative data for visual acuity, refraction and astigmatism as well as curvature data from the Pentacam and endothelial cell count were collected. The follow-up period averaged 8 months. RESULTS: In both groups visual acuity postoperatively was significantly better (Zeiss: p < 0.001, Schwind p < 0.004). The improvement in the Schwind group was less than in the Zeiss group, which is the reason why there was a significant difference between the laser systems postoperatively (p < 0.017). There were no significant changes regarding the spherical equivalent after PTK. Regarding astigmatism, there was a significant decrease in the Zeiss group (p < 0.042), while it did not change significantly in patients treated with Schwind laser (p < 0.217). Overall, this led to a significant postoperative difference between both laser systems (p < 0.014). CONCLUSION: The PTK can be recommended as an effective treatment method for patients with EBMD, regardless of the laser systems used. Patients benefit from long relief from recurrences with improved or constant visual acuity and stable refraction.

[Partial visual rehabilitation 5 and 6 years after a Gundersen total conjunctival flap procedure]. / Partielle visuelle Rehabilitation 5 und 6 Jahre nach totaler Bindehautdeckung mittels Gundersen-Flap.

BACKGROUND: We present the results of penetrating keratoplasty (PKP) after previous treatment with a total conjunctival flap in two patients. CASE REPORTS: Patient 1, a 66-year-old with a history of bilateral cement chemical burn in 1986 and external right-sided limbokeratoplasty in 2008 was treated externally with a total conjunctival flap in the right eye in 2014 due to a persistent corneal ulcer with imminent perforation. Best-corrected visual acuity (BCVA) in the right eye was light sensation, intraocular pressure on palpation was within normal range. Clinically, total conjunctival flap was present. Patient 2 was treated externally in May 2015 due to acanthamoeba keratitis in the left eye with a deep anterior lamellar keratoplasty (DALK). A re-DALK was also performed externally in the same month. A third DALK was performed externally in August 2015 due to a persistent corneal ulcer, followed by a total conjunctival flap 2 weeks later. BCVA of the left eye was light sensation and intraocular pressure on palpation was within the normal range. RESULTS: Patient 1 was treated with removal of the conjunctival flap in the right eye and penetrating central re-keratoplasty (hand-held Barron trephine; graft diameter 8.5/8.75 mm). Simultaneously, lens extraction and intraocular lens implantation were performed (as a triple procedure). Additionally, amniotic membrane transplantation (AMT) as patch and a temporal lateral tarsorrhaphy were performed. BCVA 6 months postoperatively was 0.1. The graft was clear, without any signs of rejection. Patient 2 was treated on the left eye with removal of the conjunctival flap and a penetrating central keratoplasty (hand-held Barron trephine; graft diameter 7.0/7.5 mm). An AMT as patch and a temporal lateral tarsorrhaphy were simultaneously performed. Cataract surgery was performed 3 months postoperatively and BCVA of the right eye was 0.1 thereafter. The graft was clear, without any signs of rejection. CONCLUSION: The conjunctival flap is a treatment of last resort of the (almost) penetrated corneal ulcer, which is to be used only when a keratoplasty is technically impossible. Provided the eye structure and retinal function are preserved, partial visual rehabilitation can possibly be achieved through a PKP after excision of the conjunctival flap, even years after corneal blindness.

[Stage-appropriate treatment of keratoconus]. / Stadiengerechte Therapie des Keratokonus.

Keratoconus (KC) is a progressive cone-shaped corneal protrusion that causes paracentral thinning at the apex of the cone and typically occurs asymmetrically on both sides. After a careful anamnesis and classification of the degree of severity a targeted treatment appropriate to the stage of the disease is available. If the visual acuity is no longer sufficient, rigid gas-permeable contact lenses (CL) are fitted by a specialist. Riboflavin UVA cross-linking (CXL) is recommended in cases of progression and visual acuity that is still useful for the patient. Intracorneal ring segments (ICRS) are indicated for CL intolerance in cases of reduced visual acuity and a clear central cornea. If the stage is more advanced, deep anterior lamellar keratoplasty (DALK) or penetrating keratoplasty (PKP) is recommended. A PKP is contraindicated in acute KC but deep stromal sutures for readaptation of the Descemet tear with gas filling of the anterior chamber can considerably shorten the course. Almost no other eye disease is nowadays as easily accessible for an early instrument-based diagnosis and stage-appropriate treatment as KC.

[Recurrent DMEK failure]. / Rezidivierendes DMEK-Versagen.

We report a Patient with Fuchs dystrophy who underwent three Descemet Membrane Endothelial Keratoplasties (DMEK) caused by recurrent graft failure with raise in intraocular pressure and cystoid macular edema. At the third DMEK, herpes was detected in the anterior chamber tap and an adequate therapy was initiated. At the 6 months follow-up the cornea remained clear, visual acuity was 0.8, intraocular pressure was within normal range and macular edema regressed completely. Either a latent Herpes simplex Virus (HSV) infection of the patient was reactivated or an infected donor lamella was transplanted with donor-to-host-to-donor ping-pong transmission.

[Coinfections in contact lens-associated mycotic keratitis with Pseudomonas or Acanthamoeba]. / Mischinfektionen bei kontaktlinsenassoziierter mykotischer Keratitis mit Pseudomonas oder Akanthamöben.

Contact lens-associated keratitis is becoming increasingly more frequent. Fungal keratitis is a relatively rare clinical picture but must be taken very seriously. Especially in the early stages of the disease, it may be clinically misdiagnosed and adequate treatment is therefore delayed. In treatment-resistant contact lens-associated fungal keratitis, coinfections or superinfections can occur. We present two patients with an initially unclear keratitis, in whom a fungal keratitis with coinfection of Pseudomonas aeruginosa and Acanthamoeba, respectively, could be confirmed. In both cases an urgent excimer laser penetrating keratoplasty with interrupted sutures and adequate local topical treatment for 8 weeks was successful.

Development and Assessment of a Simulator for in Vivo Confocal Microscopy in Fungal and Acanthamoeba Keratitis.

BACKGROUND AND PURPOSE: In vivo confocal microscopy (IVCM) is a non-invasive imaging technique that allows morphological analysis as a diagnostic approach of the cornea in real time, thus providing a suspected diagnosis of fungal or amoebic keratitis immediately, whereas culture or PCR require several days or even weeks. Since these infections are rare, it is difficult for ophthalmologists to gain the experience necessary to differentiate infection from normal findings or artefacts. The purpose of this project was to establish a simulator, on which physicians could practice as well as acquiring a database of IVCM images of fungal or amoebic keratitis and respective analyses. PATIENTS AND METHODS: An IVCM simulator was set up with cadaver human corneas, infected with either acanthamoeba, candida or aspergillus. Twenty-one ophthalmologists were trained in IVC microscopy first in a Dry Lab, then practically on the simulator. For evaluation, the participants were asked to fill out a standardized questionnaire, with a pre- and post-course self-assessment. RESULTS: The self-assessed theoretical and practical skills in differentiating infectious from non-infectious keratitis in IVCM significantly increased (p = 0.0001, p = 0.0002, respectively). The barrier to use this technique decreased (p = 0.0474). CONCLUSION: A very simple protocol based on a model of ex vivo corneal mycotic and amoebic infections can be used to train novices in the structured approach and diagnostic use of IVCM for corneal infections.

[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.

[Acanthamoeba endophthalmitis-a case report]. / Akanthamöbenendophthalmitis ­ Ein Fallbericht.

Diagnosis of acanthamoeba keratitis is often a clinical challenge. In most cases it is primarily confused with herpes keratitis. A coinfection with bacteria or fungi can also lead to a delayed diagnosis and initiation of treatment. A few cases reported the detection of acanthamoeba in the anterior chamber. In the case of endophthalmitis without the detection of bacteria or fungi acanthamoeba should therefore always be considered as a potential differential diagnosis. The local and systemic administration of voriconazole can be successfully used to treat acanthamoeba endophthalmitis.

[The German keratomycosis registry : Initial results of a multicenter survey]. / Das Deutsche Pilz-Keratitis-Register : Erste Ergebnisse einer multizentrischen Erhebung.

BACKGROUND AND PURPOSE: Mycotic keratitis is a serious but relatively rare disease. No targeted data collection in Germany existed until the foundation of the German Pilz-Keratitis Register in 2015. PATIENTS AND METHODS: The inclusion of retrospective and prospective patients was carried out. INCLUSION CRITERIA: diagnosis confirmed by the polymerase chain reaction (PCR), culture, histology or confocal microscopy (IVCM). Collected parameters: date of symptom onset, date and method of diagnosis, risk factors, visual acuity and findings at admission and at follow-up, conservative and surgical treatment. RESULTS: By January 2018, a total of 102 eyes from the years 2000-2017 were reported from 16 centers (64.3% female, mean age 52 years, range 18-95 years). The initial diagnosis was made correctly in only 20.6% of cases. The mean time to correct diagnosis was 31.7 ±â€¯46.9 (0-296) days. The diagnosis was confirmed in cultures in 74.5%, histologically in 30.4%, by PCR in 38.2% and IVCM in 27.4%. Fungal species identified were: 36.7% Fusarium spp., 35.8% Candida spp., 6.4% Aspergillus spp. and 21.1% other. The most important risk factor was the use of contact lenses. The most commonly used antifungal agent was voriconazole (64.7%) followed by amphotericin B (37.2%). Penetrating keratoplasty was performed in 65.7% of the cases and 8.8% of the affected eyes had to be enucleated. The visual acuity of the entire study population increased from the initial 0.16 ±â€¯0.25 (0.001-1.0) decimal to 0.28 ±â€¯0.34 (0-1.0) decimal. CONCLUSION: The correct diagnosis of fungal keratitis is often significantly delayed. The treatment can be very difficult and keratoplasty is often necessary. In order to gain a better understanding of this disease, to recognize previously unknown risk factors and, if necessary, a change in the spectrum of pathogens and to identify approaches to treatment optimization, the fungal keratitis registry will be continued.

Anatomy-based DMEK Wetlab in Homburg/Saar: Novel aspects of donor preparation and host maneuvers to teach descemet membrane endothelial keratoplasty.

Use of Descemet Membrane Endothelial Keratoplasty (DMEK) has been limited because of problems with donor preparation, i.e. tearing of the Descemet membrane and difficulties in unfolding the Endothelium-Descemet-Membrane-Layer (EDML) in the anterior chamber (AC). The purpose of this work was to describe a novel approach to teaching anatomy-based donor and recipient preparation in a DMEK-Wetlab. We teach successful mono-manual donor preparation of human corneas in organ culture not suitable for transplantation, including peripheral markers for orientation. We also teach safe recipient preparation in a freshly-enucleated pig eye in organ culture preservation medium for atraumatic introduction of the EDML roll into the AC, reliable orientation of the EDML during surgery, and stepwise unfolding within the AC. Twenty-two candidates in the 1. Homburg Cornea Curriculum HCC 2015 who practiced both preparations using three human donor corneas and three pig eyes assessed the procedure as follows: (1) overall grade of the Wetlab 1.4 (median 1, range 1 to 2 - on a scale from 1 (excellent) to 6 (terrible); (2) most participants and tutors stated that the Wetlab is most effective for colleagues who have some previous experience with corneal microsurgery. Our novel anatomy-based approach to simulating donor preparation and graft implantation for DMEK seems to meet the expectations and requirements of colleagues with previous experience in corneal microsurgery and will help to reduce the rate of complications for incipient DMEK surgeons in the future. Clin. Anat. 31:16-27, 2018. © 2017 Wiley Periodicals, Inc.

[Ultrasound biomicroscopy in giant cell arteritis]. / Ultraschallbiomikroskopie bei Riesenzellarteriitis.

Giant cell arteritis may lead to irreversible blindness due to an anterior ischemic optic neuropathy or central retinal artery occlusion. Diagnosis of the giant cell arteritis is sometimes a problem: Difficulties may arise since a negative biopsy can not rule out the diagnosis. This case report demonstrates acute changes in the temporal artery as demonstrated by Ultrasound Biomicroscopy and documents its course during therapy with corticosteroids.

[Fuchs uveitis]. / Fuchs-Uveitis.

Fuchs uveitis (FU) is a frequent, chronic course of intraocular inflammation, which is associated with a gradual onset of decreased visual acuity. The clinical manifestation of the triad of heterochromia, cataract and glaucoma varies considerably. This explains the often delayed diagnosis. Although the aetiology and pathogenesis of the changes are still unclear, there is no doubt that infections play a significant role. Intraocular antibodies directed against rubella viruses show a high association with the disease pattern, and their detection can even be used to support the diagnosis. The treatment of FU is limited to symptomatic measures. Corticosteroids are usually only moderately effective and should be used with caution due to adverse effects, with progression of cataract and secondary glaucoma. The prognosis of the disease can be regarded as favourable and depends essentially on the secondary changes.