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.

Short-term outcomes of intravitreal faricimab for refractory neovascular age-related macular degeneration.

PURPOSE: To assess the short-term outcomes of intravitreal faricimab (IVF) for previously treated refractory neovascular age-related macular degeneration (nAMD) in a real-world setting. METHODS: A retrospective monocentric study including 44 eyes treated with an upload of 4 × monthly intravitreal injections (IVI) of faricimab 6 mg/0.05 mL and followed for 4 weeks after last IVI (16 W). Patients were switched to IVF after treatment with at least three other anti-vascular endothelial growth factors (anti-VEGF). Main outcome measures included best-corrected visual acuity (BCVA), central macular thickness (CMT), subfoveal choroidal thickness (SFCT) and retinal fluid distribution. RESULTS: 44 eyes of 44 patients with previously treated refractory nAMD (63% males) were included. Mean age was 79 ± 7 years. The total number of previous anti-VEGF before switching to IVF was 32 ± 15 IVIs/eye. BCVA (logMAR) improved significantly from 0.65 ± 0.26 to 0.50 ± 0.23 at 16 W (p < 0.01). CMT (µm) decreased significantly from 422 ± 68 to 362 ± 47 at 16 W (p < 0.01). SFCT did not change significantly at 16 W (p = 0.06). The number of eyes with subretinal fluid (SRF) decreased significantly from 29 (65%) to 13 (29%) at 16 W (p = 0.001). There were no significant changes regarding the distribution of intraretinal fluid or pigment epithelial detachment (p > 0.05). A complete fluid resolution was achieved in 8 eyes (18%). No adverse events were noticed. CONCLUSION: In the short term, IVF led to a significant decrease in CMT as well as a significant improvement of BCVA and thus appears to be an effective treatment option for previously treated refractory nAMD without relevant adverse effects.

Expression of matrix metalloproteinases and their inhibitors in corneal stromal fibroblasts and keratocytes from healthy and keratoconus corneas.

PURPOSE: To examine the in-vitro expression of matrix metalloproteinases (MMP) and tissue inhibitors of metalloproteinases (TIMP) in corneal stromal cells by distinguishing between fibroblasts and keratocytes of healthy and keratoconus (KC) corneas. METHODS: Stromal cells were isolated from healthy and KC corneas (n = 8). A normal-glucose, serum-containing cell culture medium (NGSC-medium) was used for cultivation of healthy human corneal fibroblasts (HCFs) and KC human corneal fibroblasts (KC-HCFs). In order to obtain a keratocyte phenotype, the initial cultivation with NGSC-medium was changed to a low-glucose, serum-free cell culture medium for healthy (Keratocytes) and KC cells (KC-Keratocytes). Gene and protein expression of MMP-1, -2, -3, -7, -9 and TIMP-1, -2, -3 were measured by quantitative PCR and Enzyme-Linked Immunosorbent Assay (ELISA) from the cell culture supernatant. RESULTS: KC-HCFs demonstrated a lower mRNA gene expression for MMP-2 compared to HCFs. In contrast to their respective fibroblast groups (either HCFs or KC-HCFs), Keratocytes showed a higher mRNA gene expression of TIMP-3, whereas TIMP-1 mRNA gene expression was lower in Keratocytes and KC-Keratocytes. Protein analysis of the cell culture supernatant revealed lower concentrations of MMP-1 in KC-HCFs compared to HCFs. Compared to Keratocytes, TIMP-1 concentrations was lower in the cell culture supernatant of KC-Keratocytes. In HCFs and KC-HCFs, protein levels of MMP-1 and TIMP-1 were higher and MMP-2 was lower compared to Keratocytes and KC-Keratocytes, respectively. CONCLUSION: This study indicates an imbalance in MMP and TIMP expression between healthy and diseased cells. Furthermore, differences in the expression of MMPs and TIMPs exist between corneal fibroblasts and keratocytes, which could influence the specific proteolytic metabolism in-vivo and contribute to the progression of KC.

Descemet Membrane Endothelial Keratoplasty after failed penetrating keratoplasty- case series and review of the literature.

BACKGROUND: This study aims to evaluate visual outcome, central corneal thickness, and re-bubbling rate in a cohort with undersized sequential Descemet Membrane Endothelial Keratoplasty (DMEK) due to endothelial graft decompensation following primary penetrating keratoplasty (PK). METHODS: All patients who received a sequential DMEK (n = 16) or triple DMEK (n = 2) after failed primary PK between November 2020 and June 2022 were retrospectively evaluated. Analyzed parameters were corrected distance visual acuity (CDVA), central corneal thickness (CCT), re-bubbling rate and graft survival. RESULTS: 18 eyes of 18 patients were included. All patients underwent a DMEK with undersized graft after failed PK(s). Mean time between the last PK and DMEK was 102 ± 82 weeks. Mean follow-up time was 8.9 ± 4.6 months. CDVA increased significantly from 1.12 ± 0.60 logMAR preoperatively to 0.64 ± 0.49 logMAR 6 weeks postoperatively (p = 0.013). Mean CCT decreased significantly from 807 ± 224 µm before to 573 ± 151 µm 6 weeks after DMEK (p = 0.003). Re-bubbling was necessary in eight eyes (44.4%) after a median time of 7 days. The 12-month Kaplan Meier survival was 66.7%. CONCLUSION: In case of endothelial graft decompensation without stromal scars after primary PK, a DMEK can be performed for selected patients who had satisfying CDVA before the endothelial decompensation. Prior to DMEK indication, an AS-OCT should routinely be performed to circularly search for posterior steps at the PK graft margin, as well as shortly after DMEK to exclude a detachment of the endothelial graft. All patients should be informed about a higher re-bubbling rate in comparison to primary DMEK.

Calcium Electroporation versus Electrochemotherapy with Bleomycin in an In Vivo CAM-Based Uveal Melanoma Xenograft Model.

Despite recent advancements in the diagnosis and treatment of uveal melanoma (UM), its metastatic rate remains high and is accompanied by a highly dismal prognosis, constituting an unmet need for the development of novel adjuvant therapeutic strategies. We established an in vivo chick chorioallantoic membrane (CAM)-based UM xenograft model from UPMD2 and UPMM3 cell lines to examine its feasibility for the improvement of selection of drug candidates. The efficacy of calcium electroporation (CaEP) with 5 or 10 mM calcium chloride (Ca) and electrochemotherapy (ECT) with 1 or 2.5 µg/mL bleomycin in comparison to monotherapy with the tested drug or electroporation (EP) alone was investigated on the generated UM tumors. CaEP and ECT showed a similar reduction of proliferation and melanocytic expansion with a dose-dependent effect for bleomycin, whereas CaEP induced a significant increase of the apoptosis and a reduction of vascularization with varying sensitivity for the two xenograft types. Our in vivo results suggest that CaEP and ECT may facilitate the adequate local tumor control and contribute to the preservation of the bulbus, potentially opening new horizons in the adjuvant treatment of advanced UM.

Descemet Membrane Endothelial Keratoplasty (DMEK) Anesthesia Analysis.

PURPOSE: Comparison of safety and clinical results of Descemet membrane endothelial keratoplasty (DMEK) in topical, peribulbar, or general anesthesia. METHODS: Retrospective, post hoc matched study of 346 patients who received DMEK surgery with different types of anesthesia (n = 54 topical, n = 137 peribulbar, n = 155 general anesthesia). Outcome criteria were intraoperative complications, endothelial cell count (ECC), central corneal thickness (CCT) and graft rejection rate, rebubbling rate, and visual acuity (VA). Mean follow-up time was 9.4 ± 2.8 months. RESULTS: The group with topical anesthesia showed intraoperative difficulties such as vitreous pressure (p = 0.01) and difficult graft unfolding (p = 0.4), possibly leading to a higher rebubbling rate (p = 0.03) and therefore graft failure (p = 0.39). However, rebubbling and graft failure occurred more often when the graft preparation was more difficult (p = 0.2, p = 0.13, respectively), which was independent of anesthesia. All three groups achieved comparable functional results regarding VA, ECC, and CCT after 6 months. CONCLUSION: DMEK under topical anesthesia is feasible and shows comparable final visual outcomes but should be limited to selected cooperative patients and performed by experienced surgeons due to the potential for increased intraoperative challenges.

Impact of Pachychoroid and DRIL on the Treatment of Diabetic Macular Oedema with Intravitreal Bevacizumab.

PURPOSE: To evaluate the long-term outcome of intravitreal bevacizumab in eyes with diabetic macular oedema (DME) following a PRN (pro re nata) regimen. Additionally, we investigated the effect of the presence of disorganisation of the retinal inner layers (DRILs) and pachychoroid (PC) at baseline on clinical outcome. METHODS: This retrospective study included 112 naïve eyes with DME that were followed up for 2 years. All eyes were treated with six initial bevacizumab injections at monthly intervals and then received treatment according to a PRN regimen. In case of poor response to bevacizumab, therapy was switched to other agents. Main outcome measures included: best-corrected visual acuity (BCVA), central macular thickness (CMT), and number of intravitreal injections (IVI s). In addition, we examined the effect of the presence of DRILs and PC at baseline on clinical outcome. RESULTS: BVCA improved significantly and CMT decreased significantly during the first 2 years of treatment. The number of IVI s per eye was 11.1 ± 4.8 at the end of the second year. Treatment had to be switched to other agents in 47 eyes (42%). The timing of switching was 12.4 ± 6.1 months after a mean of 9.2 ± 3.3 IVI s. Patients with DRILs at baseline (29.5%) had significantly worse BCVA at all time points before and after treatment, although CMT was significantly lower before treatment and comparable to patients without DRILs during treatment. Patients with PC at baseline (35.7%) had no significant differences in BVCA and CMT at all time points compared with patients without PC. CONCLUSIONS: This study demonstrates statistically significant functional and anatomical improvement in patients with DME treated with intravitreal bevacizumab after 2 years. However, more than 40% of eyes required a switch in therapy. The presence of DRILs at baseline had a negative effect whereas the presence of PC at baseline had no effect on clinical outcome.

Impact of Donor, Host, and Surgical Parameters on High Endothelial Cell Density More Than 5 Years after Penetrating Keratoplasty.

OBJECTIVES: To investigate the correlation between postoperative endothelial cell loss (ECL) and donor, host, and surgical parameters, and to assess the clinical impact of maintaining a high endothelial cell density (ECD) of ≥ 1500 cells/mm2 5 years after penetrating keratoplasty (PKP). METHODS: This retrospective cohort study included 216 eyes with 5 years of follow-up, of which 94 had annual visits, and who underwent normal-risk elective PKP for noninfectious indications by one corneal microsurgeon (B. S.) between 2009 and 2016. RESULTS: Among the 216 eyes, ECL (39.1%) over 5 years postoperative exhibited weak positive correlations with storage solution time (p = 0.024) and postmortem time (p = 0.028), and moderately positively correlations with the preoperative ECD (p < 0.001). The 5-year postoperative ECL differed significantly between in domo-prepared (36.8%) and ex domo donor corneas (46.3%; p = 0.001). In the 94 eyes, no significant differences were found between the two groups for central pupil pachymetry (CCT) and BCVA (p > 0.074). However, CCT increased significantly between 1 and 4 years (p = 0.034) and 1 and 5 years postoperatively (p = 0.012), respectively. BCVA improved significantly at 1 year postoperatively and continued to improve until 2 years postoperatively (p < 0.001). CONCLUSION: The Lions corneal bank Saar-Lor-Lux achieved a significantly reduced ECL (36.8%) over 5 years compared to ex domo donor corneas (46.3%). A weak positive correlation was found between ECL with the storage solution time and the postmortem time, as well as a moderate positive correlation with the preoperative ECD. Although CCT increased significantly over 5 years, BCVA improved significantly from the first to the second postoperative year and remained stable thereafter.

Keratectasia severity staging and progression assessment based on the biomechanical E-staging.

Until recently, corneal topography has been the gold standard in detecting keratectasia and monitoring its progression. The recently introduced ABCD tomographic keratoconus staging system focuses on anterior ("A") and posterior ("B") radius of curvature, thinnest corneal thickness ("C"), best-corrected visual acuity with spectacles ("D") and is supplemented with the introduction of the biomechanical E-staging (BEST, "E"). The need for biomechanical staging arose from the fact of altered biomechanical characteristics of keratectasia in comparison to healthy corneas. Ectatic corneas usually exhibit a biomechanical weakening and greater deformation than healthy corneas when exposed to a biomechanical stressor such as a standardized air puff indentation as provided by the Corvis ST® (CST, Oculus, Wetzlar, Germany). The BEST is based on the linear term of the Corvis Biomechanical Index (CBI) and provides a biomechanical keratoconus severity staging and progression assessment within the CST software. This review traces the development of the BEST as an addition to the tomographic ABCD staging system and highlights its strengths and limitations when applied in daily practice for the detection, monitoring and progression assessment in keratectasia.

[The latest IC3D classification of corneal dystrophies-Overview and changes of the 3rd edition]. / Die aktuelle IC3D-Klassifikation der Hornhautdystrophien ­ Übersicht und Änderungen der 3. Auflage.

The International Committee on Classification of Corneal Dystrophies (IC3D) was founded in 2005 to address difficulties arising from the outdated nomenclature for corneal dystrophies (CD) and to correct misconceptions in the literature. For each of the 22 CDs, a separate template was created to represent the current clinical, pathological and genetic knowledge of the disease. In addition, each template contains representative clinical photographs as well as light and electron microscopic images and, if available, confocal microscopic and coherence tomographic images of the respective CD. After the first edition was published in 2008, the revised version followed in 2015. The third edition of the IC3D was published as open access in February 2024. The latest edition is intended to serve as a reference work in everyday clinical practice and facilitate the diagnosis of CD, which might sometimes be difficult. This article provides an overview of the diagnostic and treatment principles of CD and presents the IC3D and its changes over time.

[Bacterial keratitis : Clinical aspects, pathogens and treatment]. / Bakterielle Keratitis : Klinische Aspekte, Erreger und Therapie.

Bacterial infections are by far the most frequent cause of infectious keratitis in high-income countries. The clinical appearance can vary widely depending on the type and species of bacteria, ranging from small superficial infiltrates to necrotizing forms. The numerous classes of available antibiotics render the treatment scope diverse and complex, especially before the pathogen has been specified and the sensitivity to antibiotics has been tested. New therapeutic approaches to reduce bacterial virulence are in development. This CME article focuses on the clinical, diagnostic and therapeutic approaches to recognize and treat bacterial keratitis.

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.

[Impact of the ratio between graft and host corneal size on immune rejection, re-bubbling rate and postoperative endothelial cell loss in 457 eyes after Descemet membrane endothelial keratoplasty (DMEK)]. / Einfluss des Verhältnisses von Transplantatgröße zu Hornhautgröße auf Immunreaktion, Re-Bubbling-Rate und postoperativen Endothelzellverlust bei 457 Augen nach Descemet-Membrane-Endothelial-Keratoplastik (DMEK).

BACKGROUND: The aim of this study was to assess the impact of the ratio between the graft and host corneal size (RGH) on postoperative complications, such as immune reactions, re-bubbling rate and endothelial cell loss (ECL) after Descemet membrane endothelial keratoplasty (DMEK). PATIENTS AND METHODS: Retrospectively, 457 patient eyes were included which had undergone surgery between 2016 and 2019 in the Department of Ophthalmology, Saarland University Medical Center in Homburg/Saar using DMEK or triple DMEK, diagnosed as Fuchs' endothelial dystrophy (n = 431), pseudophakic bullous keratopathy (n = 9) and others (n = 17). The follow-up period extended until the end of 2020. Main outcome measures included immune reaction (IR), re-bubbling rate and the postoperative endothelial cell loss (ECL) at 6 weeks, 6 months and 12 months and whether these measures depended on the RGH. RESULTS: The RGH in this study ranged from 0.35 to 0.62 (0.46 ± 0.04). There were 33 (7.2%) postoperative IRs (DMEK n = 25; triple DMEK n = 8). The average RGH without IR (0.46 ± 0.04) was significantly (p = 0.038) smaller than in the group with IR (0.47 ± 0.05). Re-bubbling was necessary in 159 of 457 (34.8%) patient eyes. The RGH in patient eyes with re-bubbling (0.47 ± 0.04) was significantly (p = 0.014) higher than that in eyes without re-bubbling (0.45 ± 0.04). The mean preoperative endothelial cell count (ECD) was 2603 ± 251 cells/mm2 (min: 2161, max: 3500 cells/mm2). It was shown that a larger RGH had no positive influence on endothelial cell loss (r = 0.001; p = 0.974). CONCLUSION: Our results suggest that a larger graft diameter compared to host corneal size is associated with an increased rate of immune reactions and a higher re-bubbling rate after DMEK. Otherwise, a larger RGH had no positive influence on endothelial cell loss after DMEK. Accordingly, the graft size for DMEK should not be unnecessarily large, especially in eyes with Fuchs' endothelial dystrophy.

First-Year Real-Life Experience with Intravitreal Faricimab for Refractory Neovascular Age-Related Macular Degeneration.

Background: To evaluate the outcomes of intravitreal faricimab (IVF) for refractory neovascular age-related macular degeneration (nAMD) and investigate the impact of baseline optical coherence tomography, biomarkers for total IVF injections are needed. Methods: A retrospective analysis of 33 eyes of patients who completed one year (52 W) of treatment with IVF. The eyes received four IVF injections (6 mg/0.05 mL) as the upload phase. Thereafter, the treatment interval was extended to 8 or 12 weeks if disease activity was not recorded. The outcome measures included best-corrected visual acuity (BCVA), central macular thickness (CMT), subfoveal choroidal thickness (SFCT), and retinal fluid distribution. Results: A total of 33 eyes were included. CMT decreased significantly at 52 W (p < 0.01). BCVA and SFCT did not change significantly at 52 W (p > 0.05). The number of eyes with subretinal fluid decreased significantly at 52 W (p < 0.01). Complete fluid resolution was achieved in 20 eyes (60%). The total number of injections was significantly negatively correlated with the presence of hyperreflective dots at baseline (HRDs, p < 0.01) and SFCT at baseline (p < 0.01). Conclusions: IVF led to a significant reduction in CMT with stabilization of BCVA. The total number of injections was lower in eyes with HRDs and increased SFCT at baseline. This might provide clues regarding response to IVF for future studies.

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.

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.

Subfoveal choroidal thickness increases after excimer laser-assisted penetrating keratoplasty but not after excimer laser-assisted deep anterior lamellar keratoplasty.

To evaluate the impact of excimer laser-assisted deep anterior lamellar keratoplasty (Exc-DALK) and excimer laser-assisted penetrating keratoplasty (Exc-PKP) on subfoveal choroidal thickness (SFCT) in eyes with advanced keratoconus. A retrospective comparative clinical study, which compares the outcomes of 24 eyes treated with Exc-DALK (G1) against matched group of 43 eyes treated with Exc-PKP (G2) at both 2 months (T1) and 2 years (T2) postoperatively. Main outcomes included best-corrected visual acuity (BCVA), central macular thickness (CMT), and SFCT. Preoperatively, there were no significant differences between both groups regarding BCVA, CMT or SFCT (p > 0.05). There were no significant differences between both groups regarding BCVA at both follow-ups (p > 0.05). There were no significant differences between both groups regarding CMT at both follow-ups (p > 0.05). SFCT was higher in G2 than G1 at both follow-ups (p < 0.01). Compared to preoperative SFCT, there were no significant changes in SFCT in G1 at both follow-ups (p > 0.05). In G2, SFCT increased significantly at T1 (p < 0.01) and did not differ significantly at T2 (p = 0.17). SFCT increased significantly after Exc-PKP but not after Exc-DALK, which might indicate that Exc-DALK affects the choroid less and thus could represent a less traumatic approach to ocular tissue than Exc-PKP.

Postmortem sympathomimetic iris excitability.

BACKGROUND: A reliable estimation of time since death can be important for the law enforcement authorities. The compound method encompassing supravital reactions such as the chemical excitability of the iris can be used to further narrow intervals estimated by temperature-based methods. Postmortem iris excitability was mostly assessed by parasympatholytic or parasympathomimetic substances. Little is known regarding sympathomimetic agents. The present study aims to describe the postmortem iris excitability using the sympathomimetic drug phenylephrine. METHODS: Cadavers were included after body donors gave written informed consent during lifetime. Exclusion criteria were known eye disease, or a postmortem interval exceeding 26 hours. A pupillometer with a minimum measurement range of 0.5 mm was used to determine the horizontal pupil diameter before and 20 minutes after the application of phenylephrine. Increase in pupil diameter was labeled as positive reaction, unchanged pupil diameter was labeled as negative reaction, and decrease in pupil diameter was labeled as paradox reaction. RESULTS: 30 eyes from 16 cadavers (median age = 80.0; 9 males, 7 females) were examined. Initial pupil size was in median 3.5 mm (interquartile range [IQR]: 3.0-4.5 mm) and progressed to 4.0 mm (IQR: 3.5-5.0 mm) 20 minutes after drug instillation. The achieved pupil diameter difference comprised in median 0.5 mm (IQR: 0.0-1.0 mm). A positive reaction was observed in 21 cases. Negative reactions were observed in 5 cases and paradox reactions in 4 cases. Overall, there was a statistically significant difference in diameter between the initial and the reactive pupil (P = 0.0002). CONCLUSION: Although relatively rarely used, sympathomimetic drugs seem to be eligible for chemical postmortem iris excitability. Currently, assessment of postmortem iris excitability usually only involves parasympatholytic and parasympathomimetic agents. The findings of the present study give a hint that the application of a third agent with a sympathomimetic mechanism of action could provide additional information. Further studies assessing such a triple approach in the compound method in comparison with the current gold standard for estimation of time since death are mandatory to ensure reliable results.