Simulator-Based Versus Traditional Training of Fundus Biomicroscopy for Medical Students: A Prospective Randomized Trial.

INTRODUCTION: Simulation training is an important component of medical education. In former studies, diagnostic simulation training for direct and indirect funduscopy was already proven to be an effective training method. In this prospective controlled trial, we investigated the effect of simulator-based fundus biomicroscopy training. METHODS: After completing a 1-week ophthalmology clerkship, medical students at Saarland University Medical Center (n = 30) were block-randomized into two groups: The traditional group received supervised training examining the fundus of classmates using a slit lamp; the simulator group was trained using the Slit Lamp Simulator. All participants had to pass an Objective Structured Clinical Examination (OSCE); two masked ophthalmological faculty trainers graded the students' skills when examining patient's fundus using a slit lamp. A subjective assessment form and post-assessment surveys were obtained. Data were described using median (interquartile range [IQR]). RESULTS: Twenty-five students (n = 14 in the simulator group, n = 11 in the traditional group) (n = 11) were eligible for statistical analysis. Interrater reliability was verified as significant for the overall score as well as for all subtasks (≤ 0.002) except subtask 1 (p = 0.12). The overall performance of medical students in the fundus biomicroscopy OSCE was statistically ranked significantly higher in the simulator group (27.0 [5.25]/28.0 [3.0] vs. 20.0 [7.5]/16.0 [10.0]) by both observers with an interrater reliability of IRR < 0.001 and a significance level of p = 0.003 for observer 1 and p < 0.001 for observer 2. For all subtasks, the scores given to students trained using the simulator were consistently higher than those given to students trained traditionally. The students' post-assessment forms confirmed these results. Students could learn the practical backgrounds of fundus biomicroscopy (p = 0.04), the identification (p < 0.001), and localization (p < 0.001) of pathologies significantly better with the simulator. CONCLUSIONS: Traditional supervised methods are well complemented by simulation training. Our data indicate that the simulator helps with first patient contacts and enhances students' capacity to examine the fundus biomicroscopically.

Evaluation of dynamic corneal response parameters and the biomechanical E-staging after Intacs® SK implantation in keratoconus.

PURPOSE: This retrospective longitudinal study evaluated the biomechanical E-staging in KC corneas before and after intracorneal ring segment (ICRS) implantation (Intacs® SK, Addition Technology, Illinois, United States). METHODS: Biomechanical E-staging for ectatic corneal diseases was applied retrospectively on 49 KC corneas of 41 patients who underwent ICRS implantation. The main outcome parameters included the Corvis Biomechanical Factor (CBiF, the linearized Corvis Biomechanical Index and the biomechanical parameters included), the resulting biomechanical E-staging, the stress-strain index, thinnest corneal thickness (TCT), maximal anterior keratometry (Kmax), and the anterior radius of curvature (ARC). They were evaluated at 1.9 ± 1.1 months preoperatively and postoperatively after 2.8 ± 0.7, 5.8 ± 1.0, and 10.6 ± 2.3 months. RESULTS: The CBiF decreased (4.9 ± 0.5 | 4.7 ± 0.5, P = 0.0013), and the E-staging increased significantly (2.8 ± 0.8 | 3.1 ± 0.9, P = 0.0012, paired t-test) from preoperatively to the first postoperative follow-up. The difference remained significant after 6 months; however, there was no more difference after 11 months. TCT was stable, whereas Kmax and ARC significantly decreased after ICRS implantation (TCT: 464 ± 49, 470 ± 51, 467 ± 38, 461 ± 48; Kmax: 56.3 ± 4.5, 54.7 ± 4.5, 54.2 ± 4.8, 54.1 ± 4.3; ARC: 51.5 ± 3.4, 48.3 ± 3.8, 48.6 ± 3.0, 48.6 ± 3.2 preoperatively and 3, 6, and 11 months postoperatively, respectively). Besides Kmax and ARC, Ambrósio's relational thickness to the horizontal profile (ARTh) was the only parameter that was significantly lower than preoperatively at any follow-up (P ≤ 0.0024, Wilcoxon matched-pairs test). CONCLUSION: Intacs® SK implantation results in an increasing biomechanical E-staging in the first postoperative months with stabilization near preoperative values after 1 year. Significantly lower ARTh values at any follow-up document the ICRS effect and contribute to a slightly higher postoperative biomechanical E-staging value.

PCR testing for herpesviruses in aqueous humor samples from patients with and without clinical corneal endothelial graft rejection.

To compare prevalence of positive PCR tests for herpesviruses between patients with and without a history of clinical corneal endothelial allograft rejection (AGR). Retrospective cross-sectional study with two-group comparison. A total of 307 aqueous humor (AH) samples from 235 Patients and 244 eyes who underwent penetrating keratoplasty or Descemet membrane endothelial keratoplasty or had a diagnostic AH aspiration due to clinical AGR between 2019 and 2023 were tested for DNA of herpes simplex virus (HSV), varicella-zoster virus (VZV), cytomegalovirus (CMV), and Epstein-Barr virus (EBV). PCR test results were compared between the two groups (with/without AGR). Another sub-analysis examined the results of patients without a history of herpetic keratitis. A total of 8% of eyes with clinical AGR (9/108) had a positive PCR result for one of the herpesviruses (HSV:3, CMV:3, EBV:2, VZV:1). All patients in the group without AGR had negative PCR results for all previous viruses (0/136). The difference was statistically significant (p < 0.001). The sub-analysis of eyes without a history of herpetic keratitis also revealed significantly more positive herpes PCR results (7/87) in eyes with AGR than in eyes without AGR (0/42, p = 0.005). Clinical AGR after keratoplasty shows a significant correlation to viral replication. Herpetic infection and AGR could occur simultaneously and act synergistically. Timely differentiation between active herpetic infection and/or AGR is pivotal for proper treatment and graft preservation.

Long-Term Follow-Up of Pediatric Excimer Laser-Assisted Penetrating Keratoplasty for Congenital Stromal Corneal Dystrophy.

PURPOSE: The purpose of this study was to highlight characteristic clinical and microscopic findings and report the long-term follow-up of pediatric excimer laser-assisted penetrating keratoplasty (excimer-PKP) for congenital stromal corneal dystrophy (CSCD). METHODS: A 2-year-old Greek child presented with CSCD at our department. Clinical examination showed bilateral flake-like whitish corneal opacities affecting the entire corneal stroma up to the limbus. Genetic testing identified a mutation of the decorin gene (c.962delA). The variant was not present in the parents and represented a de novo mutation. The uncorrected visual acuity was 20/100 in both eyes. Excimer-PKP (8.0/8.1 mm) was performed on the right eye at the age of 2.5 years and on the left eye at the age of 3 years. Postoperatively, alternating occlusion treatment was performed. RESULTS: The light microscopic examination demonstrated a disorganized extracellular matrix of the corneal stroma characterized by a prominent irregular arrangement of stromal collagen lamellae with large interlamellar clefts containing ground substance, highlighted by periodic acid-Schiff- and Alcian blue-positive reaction detecting acid mucopolysaccharides. Electron microscopy showed disorganization and caliber variation of collagen lamellae and thin filaments within an electron-lucent ground substance. The postoperative course was unremarkable. Both grafts remained completely clear 14 years postoperatively. Corneal tomography showed moderate regular astigmatism with normal corneal thickness. The corrected distance visual acuity was 20/25 in both eyes. CONCLUSIONS: Excimer-PKP for CSCD might be associated with excellent long-term results and a good prognosis, particularly when the primary surgery is performed at a very young age. However, this requires close postoperative follow-up examinations by an experienced pediatric ophthalmologist to avoid severe amblyopia.

Severe ulcerative keratopathy following implantation of an acellular porcine corneal stromal lenticule in a patient with keratoconus.

PURPOSE: To report a case of ulcerative keratopathy following implantation of acellular porcine corneal stroma (APCS) in a patient with keratoconus (KC). METHODS: A 58 year-old patient initially presented with an ulcerative keratopathy in the left eye. Previously, several corneal procedures (including radial keratotomy, laser-in-situ keratomileusis, crosslinking) were performed for KC. Eight months ago, an APCS lenticule (Xenia corneal implant, Gebauer Medizintechnik GmbH, Neuhausen, Germany) was implanted into a stromal pocket because of progressive keratectasia. Visual acuity was hand movement. Anterior segment optical coherence tomography showed a space between the APCS lenticule and the host stroma. Excimer laser-assisted penetrating keratoplasty (PKP, 8.0/8.1 mm) was performed in the left eye. The corneal explant was investigated by light and transmission electron microscopy. RESULTS: Best-corrected visual acuity was 20/40 six weeks after PKP. Light microscopy demonstrated a stromal ulceration down to the APCS lenticule. No stromal cells could be found within the APCS lenticule eight months after implantation. The APCS lenticule did not show a green stain of the collagens with Masson-Goldner staining and exhibited a strong Periodic acid-Schiff positive reaction. Electron microscopy of the APCS lenticule revealed cross-linked collagen lamellae without cellular components. Close to the interface, corneal collagen lamellae of the host cornea were disorganized. Few vital keratocytes were present on the surface of the lenticule and appeared to cause mechanical disruption of the host stroma along the lenticule-stroma interface. CONCLUSION: APCS implantation may lead to severe complications such as ulcerative keratopathy in otherwise uncomplicated KC corneas. In such cases, excimer laser-assisted PKP or Deep Anterior Lamellar Keratoplasty are the methods of choice to restore visual acuity.

Altered Corneal Biomechanics According to the Biomechanical E-Staging in Pellucid Marginal Degeneration.

PURPOSE: The purpose of this study was to investigate corneal biomechanics in pellucid marginal degeneration (PMD) compared with healthy controls using Corvis ST (Oculus, Germany) by using the new biomechanical E-staging (based on the Corvis Biomechanical Factor, the linearized Corvis Biomechanical Index) together with tomographic parameters. METHODS: Corneal biomechanical and topographic data of 75 eyes of 75 patients with PMD and 75 eyes of 75 age-matched and sex-matched healthy controls were investigated. Topographic parameters (K1, K2, Kmax, central corneal thickness (CCT), and Belin/Ambrósio Deviation Index (BAD-D) were evaluated in dependence of and correlated with the biomechanically defined E-stages. Biomechanical parameters were also recorded for the 2 groups. RESULTS: Patients with PMD showed higher K2, Kmax, BAD-D, and Corvis Biomechanical Factor values and a lower CCT compared with healthy controls (P < 0.001). The E-stage was positively correlated with K1, K2, Kmax, BAD-D, and intraocular pressure difference and negatively correlated with CCT. Stage-dependent analysis revealed a significant increase in K1, K2, Kmax (P < 0.001), and BAD-D (P = 0.041) in stage E3 compared with E0 and a significant decrease in stage E2 in CCT (P = 0.009) compared with E0. CONCLUSIONS: This study showed that patients with PMD may have a reduced corneal stiffness compared with healthy controls which worsens with increasing E-stage. Significant changes in topographic parameters were observed at stage E2 for CCT and at stage E3 for K1, K2, Kmax, and BAD-D when compared with stage E0.

[Comparison of the Effect of Autologous Serum on Therapy Resistant Corneal Erosions and Ulcers on the Corneal Graft vs. the Patient's Own Cornea]. / Die Wirkung von autologen Serumaugentropfen bei therapieresistenten Erosiones und Ulcera der Kornea bei eigenem im Vergleich zu transplantiertem Gewebe.

PURPOSE: The aim of this study is to compare the healing of corneal epithelial defects or ulcers on the corneal graft in comparison with the patient's own cornea after treatment with 100%, undiluted autologous serum eye drops. METHODS: In a retrospective study over 7 years, we analysed 263 treatments with autologous serum eye drops of persistent corneal epithelial defects (erosions [88%] vs. ulcers [12%]). We compared the epithelial healing tendency of patients with defects on their own cornea (51.9%) vs. patients who had previously undergone penetrating keratoplasty (48.1%). Complete epithelial healing during the 28 days of treatment was considered as therapeutic success. In addition, the recurrence rate of the epithelial defects after finishing the therapy was analysed. RESULTS: 88.2% of the epithelial defects healed during 28 days of therapy. The recurrence rate during follow-up was 5.1%. There was no significant difference with respect to success rate between corneal defects on the patient's own cornea (87.8%) and on the graft (88.6%; p = 0.137). There was a significantly lower success rate for corneal ulcers (74.2%) than for erosions (90.3%; p < 0.001). The recurrence rate of erosions was 4.4%, vs. 4.3% in ulcers during follow-up. CONCLUSION: The results of our study suggest that autologous serum eye drops are a non-invasive and safe alternative treatment for persistent corneal epithelial defects - with no significant difference in patients with a defect on their own cornea vs. defects on the corneal graft. The success rate, but not the recurrence rate, is significantly worse in ulcers than in erosions.

Surgical management of complicated Descemet's membrane detachment in corneas without prior endothelial keratoplasty.

PURPOSE: To provide insights into morphologic and functional features of eyes with complicated Descemet's membrane detachment (DMD) and report clinical outcomes after surgical intervention. METHODS: Retrospective study of 18 eyes with complicated DMD between 2010 and 2022. Complicated DMD was defined if any of the following criteria applied: prior penetrating keratoplasty (PKP), corneal thinning, total DMD or persistent DMD after Air/Gas-Descemetopexy. Causes, surgical management, and clinical outcomes were analyzed. Scheimpflug tomography, anterior segment optical coherence tomography (AS-OCT) and histologic examination were performed to characterize corneas with DMD. RESULTS: Fourteen eyes with prior PKP developed spontaneous DMD after 24.2 ± 12.9 years (range = 18 months - 47 years, median = 25.7 years). Complicated DMD without prior PKP was associated in three eyes after cataract surgery and in one eye after infectious keratitis. In cases with previous PKP, AS-OCT demonstrated rupture of Descemet's membrane (DM) in five eyes and spontaneous reattachment was found in four eyes within 8 weeks of initial diagnosis, with no rupture of DM in any of the cases. There was no rupture of DM in corneas without previous PKP. After prior keratoplasty, definitive surgical treatment was repeat PKP in 13 eyes and Air/Gas-Descemetopexy in one eye. In corneas without prior keratoplasty, three eyes underwent PKP and one eye Air/Gas-Descemetopexy. Histological examination of two corneal explants revealed a severely thinned graft-host junction and a disrupted DM close to the graft-host junction. Visual acuity improved from 1.80 ± 0.58 logMAR to 0.75 ± 0.69 logMAR after prior PKP and from 1.45 ± 0.65 logMAR to 0.85 ± 1.13 logMAR without prior PKP. The postoperative course was uneventful in 16 of 18 eyes. CONCLUSION: PKP is an effective treatment option for complicated DMD, especially in ectatic corneas, whereas Air/Gas-Descemetopexy or Descemet Membrane Endothelial Keratoplasty do not address the primary issue of the curvature anomaly.

Impact of cleanroom status on the reasons for discarding organ-cultured corneal transplants in a modern eye bank - More donor corneas thanks to astronaut suit?

PURPOSE: This study investigated the influence of cleanroom conditions on the discard rates of donor corneas in a German university eye bank. METHODS: Discard rates were analysed from 2017 to 2020 at the LIONS Cornea Bank at Saarland University Medical Center. 1941 corneas from 971 donors were included. 1262 corneas (65.1%) were stored in a class D cleanroom from 2017 to 2019 and processed in a cleanroom class A sterile bank (group 1). 679 corneas (34.9%) were continuously stored in a class B cleanroom and processed in a class A cleanroom safety cabinet in the same room from 2019 to 2020 (group 2). The target parameter of this work was the number of contamination-related discards. Although they cannot be influenced by the spatial conditions, the discards due to insufficient endothelial quality, serology, contraindications, scars and technical causes were also recorded. Statistical analysis was performed using SPSS and various testing procedures. RESULTS: In group 1, significantly more corneas were discarded due to positive serology (6.9%|3.8%, p = 0.020). There was no significant change between both groups for either contamination or the other reasons for discard. CONCLUSION: Optimization of hygiene standards from cleanroom class D to B did not reduce contamination. Serology, endothelial quality, medical contraindications and the presence of scars cannot be influenced by cleanroom conditions.

Implantation of Intracorneal Ring Segments in Keratectasia: Effects on Corneal Biomechanics in 112 Eyes.

PURPOSE: The aim of this study was to analyze changes in corneal biomechanical properties after implantation of intracorneal ring segments (ICRSs) in keratectasia. METHODS: This retrospective single-center study included 112 patient eyes that underwent femtosecond laser-assisted ICRS implantation (Intacs SK; Addition Technology Inc, Des Plaines, IL) for keratectasia. Biomechanical analysis was performed using the Ocular Response Analyzer (ORA; Reichert Inc, Depew, NY), with determination of corneal resistance factor, corneal hysteresis, and Keratoconus Match Index, as well as by Corvis ST (OCULUS, Wetzlar, Germany), with determination of stiffness parameter A1, Ambrosio relational thickness to the horizontal profile (Arth), integrated radius, deformation amplitude ratio, and stress-strain index as well as Corvis Biomechanical Index and Tomographic Biomechanical Index. Data collection was performed preoperatively and 6 months postoperatively for ORA and Corvis ST and additionally after 1 and 2 years for ORA. RESULTS: The corneal resistance factor decreased significantly postoperatively (5.8 ± 1.7 mm Hg) compared with preoperatively (6.75 ± 3.7 mm Hg; P = 0.021) and increased again during follow-up (6.2 ± 1.9 mm Hg; P = 0.024), without regaining preoperative values. Corneal hysteresis and Keratoconus Match Index did not change significantly. Stiffness parameter A1 (P = 0.045) increased significantly after ICRS implantation and Arth decreased significantly from 181 ± 85 to 150 ± 92 (P = 0.016). However, there was no significant postoperative change for others Corvis parameters. CONCLUSIONS: Corneal biomechanical properties showed inconsistent changes after ICRS implantation. Classical corneal biomechanical parameters (using single central air-puff tonometers) do not seem to be suitable for follow-up after ICRS implantation.

[Modern corneal diagnostics as the key for the correct classification of the disease and optimal treatment decisions]. / Moderne Hornhautdiagnostik als Schlüssel für die korrekte Einordnung der Erkrankung und optimale Therapieentscheidung.

Corneal diseases include a wide spectrum of different manifestations (inflammatory/noninflammatory) that need to be accurately classified for precise diagnosis and targeted treatment. In addition to the anamnesis and slit lamp biomicroscopy, further device-based examinations can be performed to narrow down the diagnosis. Nowadays, modern corneal imaging provides a variety of technologies, such as topography, tomography, in vivo confocal microscopy and analysis of biomechanics, which are able to reliably classify different pathologies. Knowledge of the available examination modalities helps to guide differential diagnostic considerations, facilitating the indication for stage-appropriate microsurgical intervention.

Descemet's membrane endothelial keratoplasty is the predominant keratoplasty procedure in Germany since 2016: a report of the DOG-section cornea and its keratoplasty registry.

BACKGROUND/AIMS: This retrospective multicentric panel study provides absolute numbers, types of and indications for corneal transplantation in Germany from 2011 to 2021 and sets them into the international context. METHODS: A questionnaire was sent to the 104 German ophthalmologic surgery departments and 93 (89%) provided their data. RESULTS: The number of reported keratoplasties more than doubled from 2011 (n=4474) to 2021 (n=8998). Lamellar keratoplasties (49% posterior (n=2883), 4% anterior (n=231)) surpassed penetrating keratoplasty (PKP, 47%, n=2721) for the first time in 2014. Since 2016, Descemet's membrane endothelial keratoplasty (DMEK) has become the predominant keratoplasty procedure in Germany. Its number increased by 1.5-fold from 3850 (2016) to 5812 (2021). Main indications in 2021 were Fuchs' endothelial corneal dystrophy (FECD, 43%), pseudophakic corneal decompensation (12%), repeated keratoplasty (11%), infections (7%), keratoconus (6%) and corneal scarring (4%, others: 9%). The PKP percentage decreased from 70.2% in 2011 (n=3141) to 31.7% in 2021 (n=2853). Descemet's stripping (automated) endothelial keratoplasties (DSAEKs) decreased to 1% in 2021 (n=74). 98.6% of all posterior lamellar keratoplasties were DMEKs in Germany in 2021. The number of deep anterior lamellar keratoplasties (DALKs) remained comparable from 2011 (n=269) to 2021 (n=251, 2.8%). CONCLUSION: Main indications for corneal transplantation in Germany (2021) were FECD and pseudophakic corneal decompensation. DMEK is by far the predominant corneal transplantation procedure since 2016 followed by PKP, whose absolute number decreased only slightly during the decade from 2011 to 2021. DALK proportions remain low, but stable, whereas DSAEK decreased annually and plays a minor role in Germany. TRIAL REGISTRATION NUMBER: NCT03381794.

Baseline Characteristics of 1976 Patients With Ectatic Corneal Disorders at a Single Center From 2010 to 2021: A Cross-Sectional Study of the Homburg Keratoconus Center.

OBJECTIVES: The study objective was to analyze the baseline characteristics of keratoconus (KC) patients at the Homburg Keratoconus Center from 2010 to 2021. METHODS: This cross-sectional study included 3,674 eyes, with analysis of demographics, clinical findings, visual function, endothelial measurements, and topographic, tomographic, and corneal biomechanical data from the first visit. RESULTS: Mean patient age was 36.3±13.8 years. The mean uncorrected distance visual acuity in log of minimal angle of resolution was 0.60 (20/80, Snellen equivalent), and the corrected mean was 0.3 (20/40). Of 1976 patients, 48.9% reported eye rubbing. Mean values (ranges) were 49.4±6.3 (36.3-78.0) D for steep keratometry, 462.4±66.0 (48.0-659.0) µm for thinnest corneal thickness, 9.7±8.7 (-0.5 to 88.8) for Belin/Ambrósio enhanced ectasia total deviation, 0.8±0.4 (0.0-1.0) for the Corvis biomechanical index, 0.9±0.2 (0.0-1.0) for the tomographic biomechanical index, 0.1±0.5 (-0.9 to 2.0) for the KC match index, 8.3±1.8 (2.2-17.7) mm Hg for corneal hysteresis, 7.1±2.2 (0.0-17.0) mm Hg for corneal resistance factor, and 2,562.9±326.3 (1,011-3,937) cells/mm2 for endothelial cell density. The average ABCDE KC stage was A2B3C1D1E2. Distance-corrected visual acuity correlated strongly with topometric, tomographic, and biomechanical data ( P <0.001). CONCLUSIONS: This comprehensive description of baseline features of KC patients at a tertiary center provides a reference for further longitudinal and international multicentric studies.

The Biomechanical E-Staging: In Vivo Biomechanics in Keratoconus. / Das biomechanische E-Staging: In-vivo-Biomechanik beim Keratokonus.

Belin's ABCD keratoconus classification system allows keratoconus staging based on the criteria of anterior (A) and posterior (B) corneal curvature, thinnest corneal thickness (C), and best spectacle-corrected visual acuity (D). These parameters also provide a progression assessment, but do not take corneal biomechanics into account. The analysis of corneal biomechanics by the Corvis ST (Oculus, Wetzlar, Germany) allows for separation of healthy and keratoconus corneas, based on the Corvis Biomechanical Index (CBI) and the Tomographic Biomechanical Index (TBI). As Corvis ST measurements are highly reliable and are independent of keratoconus severity, a biomechanical parameter was developed for keratoconus corneas based on the linear term of the CBI. This provides biomechanical keratoconus staging. The Corvis Biomechanical Factor (CBiF) is the basis for the introduction of the biomechanical E-staging, which augments the ABCD classification to the ABCDE classification, thus including the cornerstone of corneal biomechanics. This article highlights strengths and limitations of the ABCDE classification. "Unilateral keratoconus" supposedly turns out to be mostly a snapshot of a highly asymmetric keratectasia. Regular astigmatism is sometimes an important differential diagnosis to keratectasia and may be difficult to differentiate from it. Furthermore, the use of the biomechanical E-staging in daily practice for progression assessment of keratoconus and after its treatment by corneal cross-linking or implantation of intracorneal ring segments will be demonstrated and discussed.

Efficacy of Simulator-Based Slit Lamp Training for Medical Students: A Prospective, Randomized Trial.

INTRODUCTION: Simulation training has an important role in medical education. In ophthalmology, simulation-based training has been shown to be significantly effective for surgical and diagnostic training in direct and indirect ophthalmoscopy. In this study, we analysed the effects of simulator-based slit lamp training. METHODS: In this prospective controlled trial, medical students in their eighth semester at Saarland University Medical Center (n = 24) who had attended a 1-week ophthalmological internship were randomized into two groups: The traditional group (n = 12) was examined directly after the 1-week internship; the simulator group (n = 12) was trained with the slit lamp simulator before passing an objective structured clinical examination (OSCE). A masked ophthalmological faculty trainer assessed the students' slit lamp skills (maximum total score 42 points [pts]): preparation (5 pts), clinical examination (9.5 pts), assessment of findings (9.5 pts), diagnosis (3 pts), commentary on the examination approach (8 pts), measurement of structures (2 pts) and recognition of five diagnoses (5 pts). All students completed post-assessment surveys. Examination grades and survey responses were compared between the groups. RESULTS: The overall performance of the slit lamp OSCE was significantly better (p < 0.001) in the simulator group than in the traditional group (29.75 [7.88] vs. 17.00 [4.75]) with significantly higher scores for the preparation and assessment of slit lamp controls (5.0 [0.0] vs. 3.0 [3.5]; p = 0.008) and localization of relevant structures (6.75 [3.13] vs. 4.0 [1.5]; p = 0.008). Consistently higher scores, but not significant, were assigned for the description of structures found (4.5 [3.38] vs. 3.25 [2.13]; p = 0.09) and the correct diagnosis (3.0 [0.0] vs. 3.0 [0.0]; p = 0.48). Surveys reflected the students' subjectively perceived knowledge gain during the simulator training for slit lamp illumination techniques (p = 0.002), recognition (p < 0.001), and assessment of the correct localization of pathologies (p < 0.001). CONCLUSION: Slit lamp examination is an important diagnostic method in ophthalmology. Simulator-based training improved students' examination techniques for localizing anatomical structures and pathological lesions. The transfer of theoretical knowledge into practice can be achieved in a stress-free atmosphere.

Corneal Perforation as a Rare and Late Manifestation of Choroidal Melanoma.

PURPOSE: To report a case of corneal perforation as a rare and late manifestation of choroidal melanoma and to highlight the major histopathological findings of this unusual combined clinical presentation. METHODS: A 74-year-old male patient presented to our department due to corneal perforation of the right eye with the absence of light perception for 6 months. The intraocular pressure was hard on palpation. Because of the protracted finding and reduced visual prognosis, primary enucleation was performed. RESULTS: The histopathological examination revealed choroidal melanoma with epithelioid and spindle cell components at the posterior pole, which was positive for Melan-A, Human Melanoma Black 45 (HMB45), BAP1, and SOX10. The anterior segment showed complete anterior chamber hemorrhage and blood remnants in the trabecular meshwork. The cornea displayed diffuse blood staining with hemosiderin and hemosiderin-loaded macrophages and keratocytes. No inflammatory cells were present near the corneal perforation, which had a width of 3 mm. Intraocular heterotopic ossification was indicative of a long-standing condition. Postoperative cancer staging was normal. CONCLUSION: Corneal perforation should be considered as a very rare and late manifestation of advanced choroidal melanoma and may result from interaction between intraocular hemorrhage, elevated IOP, and its secondary signs such as corneal blood staining.

Analysis of Various Modalities for Intraocular Pressure Measurement in Relation to Keratoconus Severity in 246 Eyes of the Homburg Keratoconus Center.

PURPOSE: Intraocular pressure (IOP) measurement may be difficult in keratoconus (KC) due to corneal protrusion and irregular astigmatism. This study aimed to assess which IOP measurement modality is least affected by KC severity. METHODS: Data from 246 corneas of 246 patients with KC were retrospectively analyzed. KC stages were determined using the Topographic KC (TKC) and ABCD KC classifications derived from Pentacam (Oculus, Germany). IOP was measured using Goldmann applanation tonometry (GAT), Ocular Response Analyzer (ORA, Reichert Instruments, USA), and Corvis ST (CST, Oculus, Germany). Cronbach alpha (CA), analysis of variance with Bonferroni correction, Dunnett T3, and Pearson correlation were performed. RESULTS: Using CA, the reliability of measurements using various modalities increased to 0.764 to 0.943 when excluding IOP Goldmann overall and in each KC stage (TKC and ABCD). Analysis of variance revealed significant differences between TKC and ABCD stages for almost all IOP modalities. The Bonferroni post hoc test showed significant differences between the measured IOP in earlier and advanced KC stages, except for the biomechanically CST-corrected IOP (bIOP). Pearson correlation analysis showed a significant correlation between IOP and thinnest corneal thickness (TCT) for all IOP modalities except bIOP. CONCLUSIONS: CST-based bIOP seems to be best suited for IOP measurement in KC because it did not correlate with TCT in contrast to IOP measurements by ORA or GAT. The measurement results from GAT in patients with KC should be interpreted with care and always in view of corneal thickness. As a thumb rule, we suggest to add at least 2 mm Hg to the measured GAT value.

In Vitro Expression Analysis of Cytokines and ROS-Related Genes in Human Corneal Fibroblasts and Keratocytes of Healthy and Keratoconus Corneas.

PURPOSE: To investigate expression of cytokines and ROS-related genes in stromal cells of healthy and keratoconus (KC) corneas. METHODS: Expression analysis was performed for cytokines including several interleukins (IL), Tumor necrosis factor-α (TNF-α), Transforming growth factor-ß1 (TGF-ß1), Interferon-γ (IFN-γ) and ROS-related genes such as Catalase, Glutathione peroxidase 1, NADPH oxidase 1, superoxide dismutase 1 in corneal fibroblasts (HCFs/KC-HCFs) or keratocytes (Keratocytes/KC-Keratocytes) by qPCR and ELISA. RESULTS: Gene and protein expression of most inflammatory markers was decreased in keratocytes compared to fibroblasts, whereas no differences were found between healthy and keratoconus cells for the majority of cytokines measured. TNF-α expression was increased at gene (KC keratocytes) and protein levels (supernatant of Keratocytes/KC-Keratocytes) compared to corneal fibroblasts. No differential expression of ROS-related genes was detected between healthy and diseased cells in both fibroblasts and keratocytes. CONCLUSION: Increased expression of several inflammatory markers described as altered in KC was not evident in KC cells in vitro.

Risk Factors for Keratoconus Progression in Children Compared with Young and Middle-aged Adults.

BACKGROUND: To investigate the risk factors for keratoconus progression in children (10 - 18 years old; age group 1) compared to young adults (19 - 35 years old; age group 2) and middle-aged adults (36 - 55 years old; age group 3). PATIENTS/METHODS: Ninety-seven children, 445 young adults, and 342 middle-aged adults underwent total ophthalmic examination including clinical refraction, slit lamp examination, corneal tomography, eye biometry, and biomechanical properties measurements. Comparisons were assessed among three age groups and between progressive and nonprogressive eyes. Logistic regression was applied to determine the potential prognostic factors for keratoconus progression in the three age groups. RESULTS: Univariate logistic regression analysis show that the most prominent factors associated with progression were corneal posterior vertical radius (RVP), eye rubbing (RUB), slit lamp corneal thinning (SLT), contact lens use (CL), and central corneal thickness (CCT) in all age groups. Additionally, the anterior chamber volume (ACV) and keratoconus match index (KMI) were associated with progression in age group 1. Location of the thinnest corneal thickness at the vertical axis (TCTy), distance from apex to the thinnest point (BADISTAPEX), scissor reflection in retinoscopy (SKIAREFLEX), and Vogt striae were associated with progression in age group 2, and TCTy, anterior and posterior asphericity (ASPA and ASPP, respectively), BADISTAPEX, SKIAREFLEX, and Vogt striae were associated with progression in age group 3. The multivariate model with the highest predictability indicated RVP, ACV, and SLT as independent determinants of progression in age group 1 (AUC: 90%, sensitivity: 88.9%, specificity: 90.9%), RVP, ACV, SLT, and SKIAREFLEX in group 2 (AUC: 81.6%, sensitivity 88.5%, specificity: 70.3%), and RVP, SLT, Vogt striae, and CL in age group 3 (AUC: 80%, sensitivity 82.8%, specificity: 73%). CONCLUSION: ACV and KMI seem to play a major role in the progression of pediatric KC compared to adults. This is probably due to different anatomical and biomechanical characteristics of a child's eye globe.