[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.

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.

[The Homburger Curriculum as a model for medical resident education for ophthalmologists at Saarland University Medical Center]. / Facharztweiterbildung an der Augenklinik des Universitätsklinikums des Saarlandes : Das Homburger Curriculum als Modell für die Facharztweiterbildung zum Augenarzt am Universitätsklinikum des Saarlandes (UKS).

BACKGROUND: The Homburger Curriculum was introduced in 2012 to enhance the medical resident education and professional satisfaction. At the same time different steps were taken to encourage applications of eligible candidates. METHODS: To address candidates, the Homburger Curriculum is presented on the department's website and a short-term hospitation was introduced. The curriculum has been divided into time slots of 4 months throughout the 5 years of residency. In addition, a booklet of documented evidence of the rotations and a Resident's Compendium were introduced. Internal and external teaching programs, additional research projects and involvement of the residents in the organization of their curriculum were introduced. The paper describes the rationale behind the new structure of the curriculum and its practical outcomes for the department (e. g. a regular standby resident to fill in unexpected gaps). RESULTS: It is discussed in detail which steps were easy to implement and which steps were more difficult to introduce. After consolidation of the numerous steps, the number of resigning residents dropped significantly and the number of applicants increased. CONCLUSIONS: The new rotation schedule guarantees every young resident to be able to work at each work area of the Department of Ophthalmology. External training courses can be planned suitable to his/her rotations. An "internal competition" for popular rotations is no longer necessary. Clear organization and transparency in all areas provide good interpersonal climate in which much work still has to be done, but by motivated and satisfied residents.

[Surgeon's Impact on Graft Endothelial Cell Density and Corneal Thickness after Penetrating Keratoplasty for Keratoconus and Fuchs' Dystrophy]. / Einfluss der individuellen mikrochirurgischen Technik auf Endothelzelldichte und Pachymetrie nach perforierender Keratoplastik bei Patienten mit Fuchs-Dystrophie oder Keratokonus.

PURPOSE: The aim of this study was to examine the short- and long-term variability of graft endothelial cell density (ECD) and central corneal thickness (CCT) after penetrating keratoplasty (PKP) between different surgeons. PATIENTS AND METHODS: 370 eyes with keratoconus (KC) or Fuchs' dystrophy (FUCHS) after standardised primary excimer laser PKP (four experienced surgeons) were analysed. ECD and CCT were determined at 12 months after PKP before suture removal, and at two years after final suture removal. RESULTS: 12 months after PKP, ECD was significantly higher for surgeon 1 in FUCHS as compared to surgeons 3 (p = 0.05) and 4 (p = 0.04), in KC it was significantly higher for surgeon 1 as compared to surgeon 2 (p = 0.001) and for surgeon 1 as compared to surgeon 4 (p = 0.006). However, in FUCHS this difference was no longer significant two years after suture removal (p > 0.5), and in KK only in comparison of surgeons 1 and 2 (p = 0.04). RESULTS concerning CCT were inhomogeneous. CONCLUSIONS: The surgeon's individual handwriting seems to have an impact on the ECD in the short-term after PKP. However, differences between surgeons tend to become insignificant in the long run after suture removal.

[Acanthamoeba keratitis]. / Akanthamöbenkeratitis.

The typical clinical appearance of acanthamoeba keratitis includes pseudodendritic epitheliopathy, perineuritis, ring infiltrates or multifocal stromal infiltrates and in some cases limbitis with infiltration of the conjunctiva and/or sterile anterior uveitis. In 83-93 % of cases of acanthamoeba keratitis the patients were contact lens wearers. Acanthamoeba keratitis is diagnosed by polymerase chain reaction (PCR), confocal biomicroscopy, in vitro cultivation and histopathological examination. Information on reliability and efficacy of conservative and surgical therapy of acanthamoeba keratitis has only been published in case series but not yet verified through randomized controlled clinical studies. After early diagnosis acanthamoeba keratitis can often be successfully treated using triple topical therapy with polyhexamide, propamidine isethionate and neomycin. Topical therapy should be continued for up to 1 year. In therapy-resistant cases cryotherapy, amniotic membrane transplantation, crosslinking therapy and therapeutic keratoplasty can be performed. The prognosis of keratoplasty following acanthamoeba keratitis is more favorable if there were no signs of infection at least 3 months before surgery.

[Keratoconus lenses: the small correction miracle]. / Keratokonuslinse: Das kleine Korrektionswunder.

Keratoconus is a non-inflammatory corneal disease associated with a cone-shaped protrusion and progressive corneal thinning. Apart from progression control and stabilizing interventions, correcting the optical error induced by a mostly highly irregular corneal surface is of paramount importance with respect to quality of life and ability to work. This goal can be achieved efficiently by contact lenses with only rare adverse conditions. This article provides a current overview on contact lens fitting in keratoconus and presents own associated results.

[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.

[CD34 and alpha-smooth muscle actin expression of keratocytes following photodynamic inactivation (PDI)]. / CD34 und Alpha-smooth-Muscle-Actin-Keratozyten-Expression nach photodynamischer Inaktivierung (PDI).

PURPOSE: Photodynamic inactivation (PDI) may be a potential treatment alternative in therapy-resistant infectious keratitis. PDI may eliminate the microorganisms from the infected cornea by damage caused through free oxygen radicals, or even by supporting different stages of activation of keratocytes and inflammatory cell response. The purpose of this study was to determine the impact of PDI on activation of human keratocytes in culture. METHODS: Primary human keratocytes were isolated by digestion in collagenase A (1 mg/mL) from human corneal buttons, and cultured in DMEM/Ham's culture medium supplemented with 10% foetal calf serum. Keratocytes underwent illumination (670 nm) for 13 minutes following exposure to 0, 50, 150 and 250 nMol/ml concentrations of the photosensitizer chlorin e6 (Ce6) in the culture medium. Twenty-four hours after treatment CD34 and α-smooth-muscle actin expression of the cells was analysed using flow-cytometry (FACS). RESULTS: Using Ce6 or illumination only, α-smooth-muscle actin expression of the cells did not change significantly. Twenty-four hours after PDI the percentage of CD34-positive keratocytes did not change significantly using 50-250 nM Ce6, however, the percentage of α-smooth-muscle actin-positive keratocytes decreased significantly at 250 nM Ce6 (p = 0.01). CONCLUSIONS: As a short-term effect, PDI seems to inhibit myofibroblastic transformation of keratocytes, but does not have an impact on activation of CD34-positive keratocytes.With this impact PDI possibly may reduce the antimicrobial defence of keratocytes.

[Immune reactions following excimer laser and femtosecond laser-assisted penetrating keratoplasty]. / Immunreaktionen nach Femtosekunden- und Excimerlaser-Keratoplastik.

In 10-20 % of conventional keratoplasties immunological graft reactions (TPR) occur, which may lead to endothelial cell loss and irreversible transplant rejection. Beside the optical advantages of non-mechanical excimer laser trephination, it does not seem to have immunological disadvantages (13.9 % TPR in keratoconus, 2.9 % in Fuchs' dystrophy after 3 years). The femtosecond laser-assisted keratoplasty has visual and refractive outcomes similar to conventional trephination. However, the "mushroom-shaped" trephination seems to have immunological disadvantages (21.8 % TPR in keratoconus after 14 months) and "top hat-shaped" keratoplasties seem to have no immunological disadvantages (6.6 % TPR in Fuchs' dystrophy after 14 months).

[What big eyes you have!]. / Was hast du für große Augen?

A 4-year-old girl presented to our department with a pain and symptom-free elevated intraocular pressure (IOP) of 44 mmHg in both eyes and with enlarged corneal diameters. Megalocornea, buphthalmos and anterior megalophthalmos were discussed as differential diagnoses. Due to age-related normal morphological, functional and electrophysiological results of the optic nerve head and a very deep anterior chamber, anterior megalophthalmos was diagnosed. No topical treatment was initiated and close ophthalmological surveillance control was recommended. To the best of our knowledge megalophthalmus anterior has not up to now been described as associated with a pathological sensitivity to minor changes in lid muscle tension causing a sudden increase of IOD.

[Acanthamoeba keratitis--a rare and often late diagnosed disease]. / Die Akanthamöbenkeratitis--ein seltenes und oft spät diagnostiziertes Chamäleon.

In 83-93% of the cases of acanthamoeba keratitis the patients are contact lens wearers. Acanthamoeba keratitis is diagnosed--with descending order of sensitivity and specificity--through polymerase chain reaction (PCR), confocal biomicroscopy, in-vitro cultivation and histopathological examination. The typical clinical appearance of acanthamoeba keratitis includes pseudodendritic epitheliopathy, perineuritis, ring infiltrate or multifocal stromal infiltrates and in some cases limbitis with infiltration of the conjunctiva and/or sterile anterior uveitis. Information on reliability and efficacy of the medical/surgical therapy for acanthamoeba keratitis has only been published for case series and It has not been verified through randomised controlled clinical studies so far. By early diagnosis, using triple-topical therapy (polyhexamid, propamidinisoethionat, neomycin) acanthamoeba keratitis often heals appropriately. However, even if diagnosed early, topical therapy should be continued for 1 year. In therapy-resistant cases cryotherapy, amniotic membrane transplantation, cross-linking therapy, and therapeutic keratoplasty are performed. The prognosis of keratoplasty following acanthamoeba keratitis is more favourable when there were no signs of infection at least during the preceding 3 months.

[Photodynamic therapy for infectious keratitis]. / Photodynamische Therapie bei infektiöser Keratitis.

Photodynamic therapy (PDT) has been used in ophthalmology for the last 10 years particularly for disorders of the posterior pole. In recent years PDT has been increasingly applied for corneal cross-linking in progressive keratoconus. The classical PDT is performed with porphyrins as photosensitizers and illumination with visible light of 630-635 nm wavelength and cross-linking with the photosensitizer riboflavin and ultraviolet illumination at 370 nm. Illumination of photosensitizers generates free oxygen radicals, which damage the cell membrane or nucleic acids of eukaryotic cells or even microorganisms. By cross-linking a stronger network of collagen fibers can additionally be achieved. Experimental studies have shown that PDT with higher concentrations of photosensitizers may induce necrosis and apoptosis of corneal cells and that survival of herpes simplex virus will be reduced on a LogMar scale by 4-5 lines, of Staphylococcus aureus, Pseudomonas aeruginosa or Candida albicans strains by 1-2 lines. Previous clinical studies have shown that PDT may heal bacterial or even acanthamoeba keratitis. Thus, some authors claim that photodynamic therapy may be a potential alternative in therapy resistant infectious keratitis. However, the limitations of this therapeutic option in particular need further investigation.

[Follicular conjunctivitis of unknown origin]. / Follikuläre Konjunktivitis unklarer Genese.

A 40-year-old female chemical laboratory assistant presented at our clinic with chronic conjunctivitis of 4 years' standing. We initially misdiagnosed her symptoms as giant papillary conjunctivitis. Topical treatment failed to produce an improvement and a biopsy was performed. Histopathological analysis showed bilateral follicular lymphoma, a subtype of the B-cell non-Hodgkin lymphoma. The patient was referred for radiotherapy. At follow-up 18 months later the patient was symptom-free.

[Sudden papilledema of unclear origin]. / Plötzliches Papillenödem unklarer Genese.

A 44-year-old patient with a known history of Crohn's disease come to our clinic with unilateral vision impairment, orbital pain, and papillary swelling. The patient was treated with methylprednisolone for 5 days. Differential diagnosis excluded ischemic, inflammatory, and tumor-related causes of the papillary swelling, which was more likely to be due to papillitis associated with the known presence of Crohn's disease. Under steroid treatment visual acuity increased from 0.1 to 0.5, and an evident improvement of the ophthalmological and neurological findings was observed. Papillitis in conjunction with Crohn's disease is a rare cause of papillary swelling and should be taken into consideration during differential diagnosis. The disorder responds to steroid therapy but does not avoid irreversible damage.

[Localization and age relations of ocular aberrations]. / Lokalisation und altersabhängige Verteilung von Aberrationen des Auges.

BACKGROUND: The aim of this study was to analyze the distribution of total, corneal, and mainly internal human third- to sixth-order aberrations (HOA) and investigate possible correlations between wavefront errors and patient age. PATIENTS AND METHODS: For this study 140 eyes of 140 subjects (age range 17-77 years) were measured three times each using Nidek Optical Path Difference scan. Mean value and standard deviation for each Zernike polynomial was computed for a 5-mm pupil diameter, and six different age groups were formed. RESULTS: There was wide individual variation in the internal wavefront aberrations. The mean root-mean-square value for HOA was 0.4563 microm+/-0.296 microm. No positive correlation was found between Zernike polynomials and increasing age. In total spherical aberration however a significant difference was found between the 26-35-year and > or =56-year age groups (p=0.0002), as well as to internal and total coma (Z8) (p=0.0487 and p=0.0117, respectively). CONCLUSIONS: The internal, corneal, and total wavefront aberrations varied widely among patients. Some significant differences were found between the age groups. No correlation between age and the internal, corneal, or total aberrations was found.