Elias Flockerzi

This retrospective multicenter cohort study investigated the incidence, treatment, and prognostic impact of dysregulated intraocular pressure (DIOP; >24 mmHg requiring therapy) in patients with acanthamoeba keratitis (AK). Eighty-one eyes from 81 patients with confirmed AK were included; co-infections were excluded. DIOP and best corrected visual acuity (BCVA) were assessed at baseline, follow-up, and after penetrating keratoplasty (PKP). Overall, 28% of eyes were managed conservatively, 46% required one PKP, and 26% required two. DIOP occurred in 4% before AK, 11% after AK onset, and 10% after the first PKP. Eyes with DIOP prior to PKP had significantly worse final BCVA compared to those without DIOP (0.5 ± 0.7 vs. 1.8 ± 1.1 logMAR, p < 0.001) and required PKP more frequently (100% vs. 67%, p = 0.01). Time to correct diagnosis was significantly longer in the AK-associated DIOP group (64 ± 50 vs. 50 ± 68 days, p = 0.03). DIOP was also associated with higher rates of prior cortisone use and complications, including fixed dilated pupil, cataract, anterior synechiae, and anterior chamber irritation. Overall, DIOP represents a major complication in AK and is linked to poorer visual outcomes. Earlier therapy may help reduce DIOP and hence improve prognosis.

This cross-sectional cohort study aimed to analyze whether corneal biomechanics differ between healthy eyes of different age, even if they appear tomographically identical. All volunteers underwent corneal Scheimpflug imaging (Pentacam) and biomechanical examination (Corvis ST, CST both Oculus, Germany). Three groups (G) were formed according to age: (G1) children aged 3–10 years ( n = 250, 7.7 ± 1.9 years (mean ± standard deviation)), (G2) adolescents aged 11–20 years ( n = 350, 15.3 ± 2.9 years) and (G3) adults ( n = 100, 48.7 ± 13.8 years). Main tomographic outcome parameters were: flat anterior (K1F)/posterior (K1B) and steep anterior (K2F)/posterior (K2B) meridians, thinnest corneal thickness (TCT) and maximal anterior keratometry (Kmax). Considering biomechanics, these were deformation amplitude ratio 2 mm (DA ratio 2 mm), integrated radius (IR), Ambrósio Relational Thickness horizontal (ARTh), stiffness-parameter (SP-A1) and corneal velocity at inward applanation (A1 velocity), stress-strain-index (SSI), Corvis Biomechanical Index (CBI), Biomechanical E-Staging (BEST) and the CST-derived non-contact (IOPnct) and biomechanically adjusted intraocular pressure (bIOP). The groups were compared with Kruskal–Wallis one-way ANOVA and Dunn’s post test. The three groups G1–G3 were tomographically comparable ( p > 0.05 for K1F/K1B/K2F/K2B/TCT/Kmax). Biomechanically, there was no difference for DA ratio 2 mm and ARTh between G1–G3. Significant differences were found for SP-A1 (G1 < G2< G3, p = 0.0125), IR (G2 < G3, p = 0.0288), A1 velocity (G1 < G2< G3, p = 0.0027), SSI (G2 < G1< G3, p < 0.0001), CBI (G3 < G2< G1, p = 0.001), BEST (G3 < G2< G1, p = 0.0015), IOPnct (G3 < G1< G2, p = 0.0006) and bIOP (G3 < G2< G1, p < 0.0001). There exist small, yet significant biomechanical differences in CST measurements between tomographically comparable healthy corneas in dependence of age indicating biomechanically weaker corneas in children than in adults.

Purpose Direct ophthalmoscopy (DO) teaching in medical curricula may be performed as classical or simulator-based DO. This interventional study evaluated both options. Methods 110 medical students received a multiple-choice questionnaire (four theory questions, six fundus photographs) prior to simulator-based (EyeSi Direct, Haag-Streit Simulation, Germany) and classical DO training (Heine BETA200, Heine Optotechnik GmbH, Germany). Training was performed in groups of eight students. Thereafter, they underwent an objective standardised clinical examination containing questions about (1) pupil dilation, (2) mydriasis contraindication, (3) ophthalmoscope adjustment and a practical test checking whether (1) optic nerve head, (2) macula, (3 – 6) upper/lower vessel arcade nasally versus temporally were identified correctly. Subsequently, classic DO was performed mutually and they reported the recognised funduscopic structures. Finally, the questionnaire was repeated one week later in combination with an evaluation of simulator-based versus classic DO. Results Students improved from an average of 4.0 ± 1.5/10 before to 8.8 ± 1.5/10 correctly answered questions after training (p < 0.0001, Wilcoxon matched-pairs test). 87|34|61 students named pupil dilating time|mydriasis contraindication and adjusted the ophthalmoscope correctly. They successfully identified the optic nerve head (n[simulator]|n[classic] DO: 110|68, p < 0.0001, Fisherʼs exact test), the macula (93|22, p < 0.0001), the upper (98|75, p = 0.0002) and lower temporal vessel arcade (101|91, p = 0.0672), the upper (84|56, p = 0.0001) and lower nasal vessel arcade (87|48, p < 0.0001). They wished for more simulator-based training, indicated more interest in ophthalmology after training and indicated an improvement in their ophthalmoscopy skills. Conclusion A standardised simulator-based approach improves medical studentsʼ skills in ophthalmoscopy and arouses professional interest in ophthalmology.

Background/Objectives: Keratoconus (KC) is the most common corneal ectasia. This condition affects quality of vision, especially when it is progressive, and a timely and stage-related treatment is mandatory. Therefore, early diagnosis is crucial to preserve visual acuity. Medical data may be used either in their raw state or in a preprocessed form. Software modifications introduced through updates may potentially affect outcomes. Unlike preprocessed data, raw data preserve their original format across software versions and provide a more consistent basis for clinical analysis. The objective of this study was to distinguish between healthy and KC corneas from raw optical coherence tomography data by using a convolutional neural network. Methods: In total, 2737 eye examinations acquired with the Casia2 anterior-segment optical coherence tomography (Tomey, Nagoya, Japan) were decided by three experienced ophthalmologists to belong to one of three classes: ‘normal’, ‘ectasia’, or ‘other disease’. Each eye examination consisted of sixteen meridional slice images. The dataset included 744 examinations. DenseNet121, EfficientNet-B0, MobileNetV3-Large and ResNet18 were modified for use as convolutional neural networks for prediction. All reported metric values were rounded to four decimal places. Results: The overall accuracy for the modified DenseNet121, modified EfficientNet-B0, modified MobileNetV3-Large and modified ResNet18 is 91.27%, 91.27%, 92.86% and 89.68%, respectively. The macro-averaged sensitivity, macro-averaged specificity, macro-averaged Positive Predictive Value and macro-averaged F1 score for the modified DenseNet121, modified EfficientNet-B0, modified MobileNetV3-Large and modified ResNet18 are reported as 91.27%, 91.27%, 92.86% and 89.68%; 95.63%, 95.63%, 96.43% and 94.84%; 91.58% 91.65%, 92.91% and 90.24%; and 91.35%, 91.29%, 92.85% and 89.81%, respectively. Conclusions: The successful use of a convolutional neural network with raw optical coherence tomography data demonstrates the potential of raw data to be used instead of preprocessed data for diagnosing KC in ophthalmology.

N/a Received: 08 October 2025 Accepted: 01 December 2025 Accepted Manuscript online: 02 December 2025 © . Thieme. All rights reserved. Georg Thieme Verlag KG Oswald-Hesse-Straße 50, 70469 Stuttgart, Germany

Das Hornhautendothel als innerste Schicht der menschlichen Augenhornhaut fungiert einerseits als Barriere zwischen Kammerwasser und Hornhaut sowie andererseits über seine Pumpfunktion als Garant einer kompensierten Hornhaut. Angeborene Dystrophien oder altersbedingte Veränderungen und Degenerationen der Endothelschicht können diese Funktionen beeinträchtigen und werden in diesem Übersichtsartikel dargestellt. The corneal endothelium is the innermost layer of the human cornea and it acts as a barrier between the aqueous humor and the corneal stroma, thus maintaining the hydration of the cornea. Both congenital dystrophies including (1) Fuchs’ endothelial corneal dystrophy (FECD), (2) posterior polymorphous corneal dystrophy (PPCD), (3) congenital hereditary endothelial dystrophy (CHED), (4) X-linked endothelial corneal dystrophy (XECD) and age-related degenerations like (5) pseudoexfoliation-related (PEX) keratopathy, (6) pseudophakic bullous keratopathy (PBK), (7) iridocorneal endothelial (ICE) syndromes and endothelial graft rejection after keratoplasty can impair this function and are described in this review article. Article published online: 17 November 2025 © 2025. Thieme. All rights reserved. Georg Thieme Verlag KG Oswald-Hesse-Straße 50, 70469 Stuttgart, Germany

Das Hornhautendothel als innerste Schicht der menschlichen Augenhornhaut fungiert einerseits als Barriere zwischen Kammerwasser und Hornhaut sowie andererseits über seine Pumpfunktion als Garant einer kompensierten Hornhaut. Angeborene Dystrophien oder altersbedingte Veränderungen und Degenerationen der Endothelschicht können diese Funktionen beeinträchtigen und werden in diesem Übersichtsartikel dargestellt. The corneal endothelium is the innermost layer of the human cornea and it acts as a barrier between the aqueous humor and the corneal stroma, thus maintaining the hydration of the cornea. Both congenital dystrophies including (1) Fuchs’ endothelial corneal dystrophy (FECD), (2) posterior polymorphous corneal dystrophy (PPCD), (3) congenital hereditary endothelial dystrophy (CHED), (4) X-linked endothelial corneal dystrophy (XECD) and age-related degenerations like (5) pseudoexfoliation-related (PEX) keratopathy, (6) pseudophakic bullous keratopathy (PBK), (7) iridocorneal endothelial (ICE) syndromes and endothelial graft rejection after keratoplasty can impair this function and are described in this review article. Article published online: 17 November 2025 © 2025. Thieme. All rights reserved. Georg Thieme Verlag KG Oswald-Hesse-Straße 50, 70469 Stuttgart, Germany

Zusammenfassung Keratektasien, darunter der Keratokonus, sind pathologische Verkrümmungen der menschlichen Augenhornhaut, die durch Progression zu einer dauerhaften Visuseinschränkung führen können. Mittels Crosslinking kann der Ist-Zustand stabilisiert werden. In Deutschland existieren festgelegte Kriterien für die Indikation eines Crosslinkings, darunter die Zunahme der maximalen Vorderflächenverkrümmung K_max (maximale anteriore Keratometrie) um ≥ 1 Dioptrie (D) binnen 12 Monaten. Leider gibt es noch keine allgemeingültigen Standards für die Progressionsbeurteilung von Keratektasien. Diese Übersicht stellt Möglichkeiten der topographischen, tomographischen und biomechanischen Progressionsbeurteilung beim Keratokonus vor.