Structural changes in the corneal subbasal nerve plexus in keratoconus

Background Corneal confocal microscopy (CCM) allows visualizing slightest alterations within the corneal subbasal nerve plexus (SNP). Recent CCM studies based on the analysis of three–five CCM images per eye assumed a reduced corneal nerve fibre length (CNFL) in keratoconus (KC). Methods The SNP of KC patients (n = 23, 13 contact lens wearing, 10 noncontact lens wearing) and patients without KC (n = 16) was examined by 10 CCM images of one eye per patient. The CNFL per frame area was calculated, and the SNP tortuosity was quantified by measuring (a) the amplitude of the curves and (b) the area under the curve (AUC) formed by the SNP. Results Analysing 390 non‐overlapping confocal images revealed the CNFL (mm/mm2) to be significantly lower in KC (16.4 ± 1.9 mm/mm2) than in healthy corneae (23.8 ± 3.3 mm/mm2, p < 0.0001; mean ± SD; p‐value calculated using the Mann–Whitney U‐test), without a difference between contact lens wearing and noncontact lens wearing KC patients (p = 0.4). Amplitudes and AUCs analysed as median with 25th and 75th percentile were significantly increased in KC (amplitude 33/23/41 µm and AUC 2839/1545/3444 µm2) compared to healthy corneae (amplitude 24/18/28 µm and AUC 1870/1193/2327 µm2, p < 0.0001). Conclusions Corneal confocal microscopy (CCM) visualizes slightest alterations within the SNP in KC including (a) a significantly lower CNFL and (b) an enhanced winding course of the SNP. The significantly lower CNFL observed in KC may support the hypothesis of a neurodegenerative aspect of the disease and might be a measure to be correlated with the severity and progression of the disease

Morphological and Functional Aspects and Quality of Life in Patients with Achromatopsia

(1) Background: Achromatopsia is a rare disease of which the natural course and impact on life are still unknown to this date. We aimed to assess the morphological, functional characteristics, and quality of life in a large sample size of patients with achromatopsia. (2) A total of 94 achromats were included in this retrospective cohort study. Sixty-four were patients of the Department of Ophthalmology, Saarland University Medical Centre in Homburg/Saar, Germany, between 2008 and 2021. Thirty further participants with achromatopsia from the national support group were included using an online questionnaire, which is available under ‘Supplementary data’. Statistical analysis was performed using SPSS Version 25; (3) The 94 patients (37 males (39.4%) and 57 females (60.6%)) showed a mean age of 24.23 ± 18.53 years. Visual acuity was stable (SD ± 0.22 logMAR at 1.0 logMAR) over a time of observation from 2008 to 2021. Edge filter glasses were the most used optical aids, while enlarged reading glasses were the most used low vision aids. (4) Conclusions: Our findings give an insight into describing the natural process and the quality of life of achromatopsia. The results demonstrate that achromatopsia is a predominantly stationary disease. The individual prescription of edge filters and low-vision aids is essential following a personalised fitting

Hypoxic stress increases NF-κB and iNOS mRNA expression in normal, but not in keratoconus corneal fibroblasts

Background Keratoconus (KC) is associated with oxidative stress and hypoxia and as several times discussed, potentially with inflammatory components. Inflammation, hypoxia, and oxidative stress may result in metabolic dysfunction and are directly linked to each other. In the current study, we investigate the effect of hypoxia through NF-κB signaling pathways on iNOS, hypoxia-induced factors (HIF), ROS, and proliferation of normal and KC human corneal fibroblasts (HCFs), in vitro. Methods Primary human KC-HCFs and normal HCFs were isolated and cultured in DMEM/Ham’s F12 medium supplemented with 5% fetal calf serum. Hypoxic conditions were generated and quantitative PCR and Western blot analysis were performed to examine NF-κB, iNOS, HIF, and PHD2 expression in KC and normal HCFs. ROS level was analyzed using flow cytometry and proliferation by BrdU-ELISA. Results Hypoxia increased NF-κB mRNA and protein expression in normal HCFs, but in KC-HCFs NF-κB mRNA and protein expression remained unchanged. Hypoxic conditions upregulated iNOS mRNA expression of normal HCFs, but iNOS mRNA expression of KC-HCFs and iNOS protein expression of both HCF types remained unchanged. Hypoxia downregulated HIF-1α and HIF-2α mRNA expression in normal and KC-HCFs. PHD2 mRNA expression is upregulated under hypoxia in KC-HCFs, but not in normal HCFs. PHD2 protein expression was upregulated by hypoxia in both HCF types. Total ROS concentration is downregulated in normal and KC-HCFs under hypoxic conditions. Proliferation rate of KC-HCFs was upregulated through hypoxia, but did not change in normal HCFs. Conclusions Hypoxia increases NF-κB and iNOS mRNA expression in normal HCFs, but there does not seem to be enough capacity in KC-HCFs to increase NF-κB and iNOS mRNA expression under hypoxia, maybe due to the preexisting oxidative stress. HIF and PHD2 do not show altered iNOS regulation under hypoxic conditions in KC-HCFs, and therefore do not seem to play a role in keratoconus pathogenesis. An increased proliferation of cells may refer to compensatory mechanisms under hypoxia in KC. Understanding the mechanism of the altered regulation of NF-κB and iNOS in KC-HCFs will provide better insight into the potential inflammatory component of the KC pathogenesis

The Impact of the First COVID-19 Lockdown Period on the Inpatient and Outpatient Volume of a University Based Tertiary Referral Center with Corneal Subspecialization in Germany

Background/Aims: To determine the impact of COVID-19 on the number of in- and outpatients surgical and diagnostic procedures performed at a southwestern German university hospital with corneal subspecialization. Methods: A retrospective examination of the number of inpatients, several outpatients subunits, in- and outpatient surgeries as well as diagnostic procedures at the Department of Ophthalmology, Saarland University Medical Centre during the COVID-19 pandemic “lockdown period” from 18 March until 8 May 2020 in comparison with the corresponding period in 2019 (source: SAP database and electronic patient record FIDUS). Results: The year 2020 showed a significant decrease in the number of inpatient surgeries with a total number of 285 vs 412 in 2019. However, the number of corneal transplantations increased significantly (60 in 2020 vs 54 in 2019, p=0.0089). In the various outpatient units of our department, we observed a significant decrease in the number of consultations (1.711 in 2020 vs 3.194 in 2019), especially for cataract surgery consultations (34 vs 137, p<0.0001). The number of outpatient surgeries was significantly reduced in 2020, especially for cataract surgery (64 vs 216, p=0.007) and intravitreal injections (577 vs 768, p<0.0001). Conclusion: Despite taking all the necessary precautions to ensure that our medical care can continue to be available reliably and completely safe during the “Corona lockdown period”, the number of in- and outpatient surgeries and the number of outpatient consultations decreased significantly. However, the number of corneal transplantations still increased

Scanning-slit topography in patients with keratoconus

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Corneae from body donors in anatomy department: valuable use for clinical transplantation and experimental research

Background: Explanted corneae are highly needed for the surgical management of patients with severe corneal diseases. The aim of this study was to determine whether the body donors from the Institute of Anatomy are a suitable source of donor corneae. Methods: At the Institute of Anatomy at Saarland University Medical Center in Homburg, corneae are prelevated from body donors who had consented to the removal of tissues for transplantation purposes during their lifetime. Following the report of death, the LIONS Eye Bank is informed and the contraindications of corneal explantation are clarified. Obtaining a blood sample within 24 h postmortem is mandatory. Results: The Institute of Anatomy had 150 body donors in the time period from January 2018 to June 2019. Out of these, 68 (45.3%) were reported to the Eye Bank. The age of the donors (median 82 years (range: 57–96)) is not critical since the quality of the corneae depends on the number of endothelial cells (mean: 2109 ± 67 cells/mm2 (range: 511–2944 cells/mm2)). Contraindications were present in 19 (12.6%) cases. The corneae were extracted from 49 (32.7%) body donors. Out of these 98 corneae, 46 (46.9%) were successfully transplanted. Of all non-transplanted corneae, 6 (6.1%) were microbiologically contaminated, 10 (10.2%) had a positive serology, 22 (22.5%) had an endothelial cell count < 2000 cells/mm2 and 6 (6.1%) are at time of this analysis still in culture medium. The non-transplanted tissues were used for research. Conclusions: Explanted corneae from the Institute of Anatomy are a valuable option in obtaining grafts for corneal transplantation, which is why we are working toward on expanding cooperation with this department

Eye-Tracker-Guided Non-Mechanical Excimer Laser Assisted Penetrating Keratoplasty

Purpose: The purpose of the study was to implement a new eye tracking mask which could be used to guide the laser beam in automated non-mechanical excimer laser assisted penetrating keratoplasty. Materials and methods: A new trephination mask design with an elevated surface geometry has been proposed with a step formation between conical and flat interfaces. Two recipient masks of 7.5/8.0 mm have been manufactured and tested. The masks have outer diameter of 12.5 mm, step formation at 10.5 mm, and slope of conical surfaces 15°. Its functionality has been tested in different lateral positions and tilts on a planar surface, and pig eye experiments. After successful validation on porcine eyes, new masks have been produced and tested on two patients. Results: The build-in eye tracking software of the MEL 70 was always able to capture the masks. It has been shown that the unwanted pigmentation/pattern induced by the laser pulses on the mask surface does not influence the eye-tracking efficiency. The masks could be tracked within the 18 × 14 mm lateral displacement and up to 12° tilt. Two patient cases are demonstrated. No complications were observed during the surgery, although it needs some attention for aligning the mask horizontally before trephination. Stability of eye tracking masks is emphasized by inducing on purpose movements of the patient head. Conclusion: Eye-tracking-guided penetrating keratoplasty was successfully applied in clinical practice, which enables robust tracking criteria within an extended range. It facilitates the automated trephination procedure of excimer laser-assisted penetrating keratoplasty

Recurrent ligneous conjunctivitis after cataract surgery in a 67-year-old male patient: a case report

Background: Ligneous conjunctivitis is a rare form of chronic pseudomembranous conjunctivitis which usually starts during infancy. We report on an unsual case of recurrent ligneous conjunctivitis after cataract surgery in a 67-year-old male patient. Methods: The equipment used for the slit-lamp images was a Haag Streit slit lamp BX900 Sn 00,406 with 16×magnifcations. The used batch number of the camera was sn00406 and the software was from the company CCS Pawlowski Merge Eye. There were no flters used. The images were saved with a resolution of 300 DPI. Neither downstream nor averaging was used to enhance the resolution of the image in the case presentation section or the fgure legend. The equipment used for the cross-sectional histologic images was a Zeiss Axioskop 40 microscope with an objective lens Zeiss A-Plan×20/0.45 (Zoom 6.3×TV 2/3″″C). The used camera was AxioCam MRc5 and the software was ZEN 3.2. The cross-sectional histologic images were saved with a resolution of 2584×1936 Pixels. Neither downstream nor averaging was used to enhance the resolution of the image in the case presentation section or the fgure legend. Case presentation: This is a rare case report of ligneous conjunctivitis in a 67-year-old male patient who presented a recurrent conjunctival granuloma after fve excisions following cataract surgery in his left eye. We performed a tumor excision with free conjunctival autograft. The histology showed a fbrin crust including macrophages, granulocytes, lymphocytes, and reactively altered squamous cell nests. These fndings were consistent with a ″pseudomembrane in conjunctivitis lignosa″. We administered a topical combination of plasminactivator, heparin, cortisone and cyclosporine. Conclusion: This treatment with the combination of plasminactivator, heparin, cortisone and cyclosporine has proven to be efective in preventing the recurrence of ligneous conjunctivitis

Impact of intravitreal ranibizumab, aflibercept and bevacizumab on retinal ganglion cell and nerve fibre layer thickness in Neovascular age-related macular degeneration

Purpose: To compare the effects of monotherapy with intravitreal ranibizumab, aflibercept and bevacizumab on retinal ganglion cell layer (RGCL) and retinal nerve fibre layer (RNFL) in patients with naïve neovascular age-related macular degeneration (nAMD). Methods: This is a retrospective cohort study with three-groups comparison. 83 patients and 97 eyes on continuous monotherapy with an intravitreal anti-vascular endothelial growth factor (anti-VEGF) were followed for 24months and divided into three groups according to anti-VEGF (aflibercept: 25 eyes, ranibizumab: 34 eyes, bevacizumab: 38 eyes). Main outcome measures included: RGCL and RNFL thickness, best corrected visual acuity (BCVA), central macular thickness (CMT), macular volume (MV) and the presence of intraretinal fluids (IRF), subretinal fluids (SRF) and retinal pigment epithelial atrophy (RPE-atrophy). All outcome measures were recorded at the time of the first injection, 1 and 2years after treatment and compared longitudinally and between groups. Results: The mean age was 79±7years. The RGCL thickness, MV, CMT and the presence of IRF and SRF decreased significantly within all three medication groups (p<0.05 for all) with no significant difference between groups over the 2-year follow-up period (p>0.10 for all). The decrease in RNFL thickness was not significant within or between the groups after a 2-year follow-up (p>0.055 for all). RPE-atrophy increased significantly after 2 years in all three groups (p<0.028 for all) with no significant difference between groups at all three time points (p>0.307 for all). BCVA was comparable between the three groups over the 2-year follow-up period (p>0.22 for all). Conclusions: Monotherapy with intravitreal aflibercept, bevacizumab and ranibizumab was associated with comparable significant decreases in RGCL thickness, CMT, MV, IRF and SRF in naïve nAMD patients during the first 2 years of treatment. Furthermore, no significant differences either in BCVA or RNFL thickness were observed between the three intravitreal anti-VEFGs during the first 2 years of treatment