Central Stroma Research Articles

Prospective In Vivo Confocal Microscopy of the Central Cornea in Terrien Marginal Degeneration.

To analyze central corneal in vivo confocal microscopy (IVCM) in Terrien marginal degeneration (TMD). An observational prospective case-control study. Ten Finnish patients with TMD from a tertiary referral center were compared with 10 age- and sex-matched healthy volunteers. Seven patients had bilateral TMD. Age, anterior segment optical coherence tomography, extent of thinning in clock hours, grade of microdots, and stage of TMD were analyzed. According to Süveges and Wang classification, the median stage of TMD was 2 (range, 2-3) and 2 (range, 2-6), respectively. Twelve (71%) of 17 eyes with clinical TMD showed corneal thinning at all clock hours. The median age at the time of examination was 70 years (range, 28-81), and the median time from diagnosis 8.8 years (range, 6.0-15.2). By IVCM, the epithelium, subepithelial nerve plexus, and endothelium were intact in all eyes. The anterior stroma showed bilateral hyperreflective dots in the central cornea beneath the subepithelial nerve plexus in all eyes, and larger patches were detected in the posterior stroma anterior to Descemet membrane; both were invisible by anterior segment optical coherence tomography. As compared with controls, the grade of anterior microdots increased faster with age before the age of 65, and that of posterior stromal patches was higher. Two patients additionally had bilateral hyperreflective needle-like deposits in the anterior and midstroma. By IVCM, TMD is characterized regardless of clinical laterality by bilateral microdots in the central corneal stroma. They might be a supporting diagnostic criterion and alone could suggest subclinical disease.

An Ayurvedic methodology for managing PCOD - A Case Report

Polycystic ovarian disease (PCOD) is a heterogenous endocrine disorder characterized by ovarian cysts, anovulation, and hormonal fluctuations, impacting women’s health in various ways. PCOD has transformed into a lifestyle disorder due to sedentary habits, excessive consumption of fast food, and an unhealthy lifestyle. Predisposing risk factors such as genetics, neuroendocrine factors, lifestyle and environmental influences, as well as obesity, play significant roles in the development of PCOD. In Ayurveda, PCOD cannot be correlated to any one particular disease; it can be related to certain diseases like Vandhya, Nasthartava, Aratava Kshaya, Pushpaghni Jataharini, etc. and must be controlled according to the Dosha Dushya vitiation. In this present case study, a 21 year old female patient came with symptoms of scanty menses, acne over face and weight gain in the OPD of Kayachikitsa. The USG report reveals PCOD changes in both ovaries as both ovaries are bulky in size right ovary, vol = 18cc and left ovary, vol = 13.2cc with multiple peripherally arranged follicles with central echogenic stroma. The result was determined based on the relief of clinical symptoms and the findings from the ultrasound report. Therefore, in this case study, drugs such as Dashmool Kwath, Narikanti, Cystogrit diamond etc. was given which have Lekhaniya properties results into reducing the size of ovary and effectively alleviate Kapha Dosha and Ama, facilitating the treatment of Sroto-Dusti and removing obstructions caused by Apana Vayu, ultimately enhancing menstrual flow.

In vivo confocal microscopy findings after Descemet stripping only with and without topical ripasudil supplementation in Fuchs endothelial dystrophy

PurposeTo report corneal epithelial and corneal endothelial cell (CEC) changes following Descemet stripping only (DSO) with and without topical ripasudil using in vivo confocal microscopy (IVCM). MethodsProspective interventional case series of patients who underwent DSO for Fuchs endothelial dystrophy with or without postoperative topical ripasudil (4%, 6 times per day). Patients underwent IVCM (ConfoScan 3; NIDEK Technologies, Padova, Italy) at baseline, monthly until corneal clearance, and then every 6 months. En face images were obtained of the epithelium, anterior and posterior corneal stroma, and endothelium of the central and superior cornea. The epithelial and endothelial layer images were evaluated qualitatively. ResultsIVCM imaging was obtained from 34 patients, 26 (76%) of whom were supplemented with ripasudil and 8 (24%) of whom were not. Two eyes (6%) did not clear and required a keratoplasty. IVCM confirmed epithelial and endothelial cell morphology changes and reestablishment of a CEC mosaic. Hyperreflective nuclei, pleomorphism, multinucleated cells, and pseudoguttae were identified within the descemetorhexis. In patients on ripasudil, epithelial cells demonstrated transition from stratified squamous to spindle cell shape in regions of ripasudil-induced honeycomb edema. Migrating cells adopted an amoeboid shape and cytoplasm elongation when crossing to central stroma. Transient epithelial cell morphology changes and endothelial cell amoeboid shape changes appear to be uniquely associated with ripasudil. Rarely, figures were noted in both ripasudil-treated and non-ripasudil-treated corneas that resembled mitotic bodies. ConclusionsCECs display a range of adaptive mechanisms during healing to re-form the endothelial mosaic following DSO. Ripasudil administration appears to induce unique epithelial and endothelial cell changes.

Clinical, Anatomical, and Densitometric Changes following Dresden vs. Accelerated Corneal Cross-Linking in Progressive Keratoconus.

To compare clinical, anatomical, and densitometric changes following Dresden (DCXL) vs. accelerated (ACXL) corneal UVA cross-linking (CXL; Avedro KXL, Geuder, Heidelberg, Germany) in progressive keratoconus (KC). In this retrospective study, we analyzed 20 patients following DCXL (3 mW/cm², 30 min, 5.4 J/cm²) and 44 patients following ACXL (9 mW/cm², 10 min, 5.4 J/cm²) between January 2016 and February 2020. Uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), central corneal thickness (CCT), steepest keratometry (Kmax), keratoconus index (KI), thinnest pachymetry (Pthin), and corneal densitometry (CD) were measured before and 3, 6, 12, and 24 months after CXL. During the follow-up period, no changes in UCVA, BSCVA, Kmax, KI, or Pthin occurred. CCT significantly decreased 3 months after DCXL (p = 0.032) and ACXL (p = 0.006). At the 12- and 24-month follow-up, CCT remained decreased in the DCXL (p = 0.035, 0.036, respectively) but not in the ACXL group. At the 12-month follow-up, the reduction in CCT was significantly greater in DCXL compared to ACXL (p = 0.012). At the 3-, 6-, 12-, and 24-month follow-ups, we found a significant increase in the anterior stroma CD following DCXL (p = 0.019, 0.026, 0.049, 0.047, respectively) but not ACXL. The CD changes were localized in the central concentric zones (0.0 to 6.0 mm). No intra- or postoperative complications occurred. ACXL and DCXL effectively halted KC progression. ACXL proved to be a safe time-saving alternative to conventional DCXL. DCXL led to a reduction in CCT and an increment in the CD of the central anterior stroma during 24 months of follow-up.

Clinical and Morphological in Vivo Confocal Microscopy Findings following a Modified Biphasic Higher Fluence Transepithelial Corneal Crosslinking

Purpose: To compare the refractive efficacy and morphological changes in the cornea following a novel biphasic higher fluence transepithelial corneal crosslinking (BI-TE-CXL) and transepithelial corneal crosslinking (TE-CXL) in adults keratoconus. Methods: Patients with progressive keratoconus who required corneal crosslinking were assigned to the BI-TE-CXL group (32 eyes, phase 1: 7.2 J/cm2 for 5 min and 20 s of pulsed-light exposure, KXL, Glaukos-Avedro; phase 2: 3.6 J/cm2 for 6 min and 40 s of continuous light exposure at the front curvature apex with a 6 mm diameter light spot, UVX-2000, IROC) or the TE-CXL group (32 eyes, uniform 7.2 J/cm2 for 5 min and 20 s of pulsed-light exposure, KXL, Glaukos-Avedro). Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), corneal fluorescein staining (CFS), corneal topography, anterior segment optical coherence tomography (AS-OCT), and in vivo corneal confocal microscopy (IVCM) were performed 3, 6, 12 and 24 months after surgery. Results: The CFS scores in the BI-TE-CXL group were significantly higher than those in the TE-CXL group on the first two days after surgery (p < 0.001). The Kmax (at 12 and 24 months) and CDVA (logMAR) were significantly lower in the BI-TE-CXL group than those in the TE-CXL group (p < 0.05). The corneal demarcation line under AS-OCT was visible in 81.3% of patients in the BI-TE-CXL group and 15.6% in the TE-CXL group. The depth of the demarcation line under IVCM was significantly deeper in the BI-TE-CXL group (248.3 ± 25.0 μm) than that of the TE-CXL group (136.5 ± 15.6 μm) in the central cornea (p < 0.001). The cross-linked collagen structures in the central cornea were still present after 12 months in the BI-TE-CXL group. No significant difference in sub-basal nerve density between the two groups (p > 0.05). Conclusions: Following BI-TE-CXL, CDVA was significantly improved, accompanied by deeper demarcation line depth and persistent crosslinked structures in the central corneal stroma.

Topography-guided transepithelial corneal collagen cross-linking by sequential ultraviolet A irradiation in different diameters for progressive keratoconus in adults

Objective: To compare the efficacy and safety of a novel customized topography-guided transepithelial corneal collagen cross-linking (TG-CXL) procedure by sequential ultraviolet A irradiation in different diameters and conventional transepithelial corneal collagen cross-linking (TE-CXL) in adult patients with progressive keratoconus. Methods: A prospective cohort study was conducted. Adult patients diagnosed with progressive keratoconus in the Affiliated Xiamen Eye Center of Xiamen University were continuously recruited and randomly assigned to receive the TG-CXL or TE-CXL procedure from March 2020 to March 2021. Patients in the TE-CXL group were irradiated in the central 9-mm zone of the cornea (total energy, 7.2 J/cm2; irradiance, 45 mW/cm2), while patients in the TG-CXL group were first irradiated with the protocol used in the TE-CXL group, and further irradiated in the central 6-mm zone (total energy, 3.6 J/cm2; irradiance, 9 mW/cm2). The subjective symptom of pain and corneal fluorescein sodium staining were scored within postoperative 3 days. Slit lamp examination, measurements of uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA), corneal topography, anterior segment optical coherence tomography, in vivo corneal confocal microscopy, corneal endothelial cell count, and non-contact tonometry were performed before surgery and at 3, 6, and 12 months after surgery. Results: A total of 66 patients were enrolled (mean age, 23.0±3.3 years old), with 33 patients (33 eyes) in each group. No statistically significant differences were found in age, gender, and maximum keratometry (Kmax) between the two groups (P>0.05). On day 1 after surgery, the average pain score of the TG-CXL group (2.21±0.45) was significantly higher than that of the TE-CXL group (1.32±0.33) (P<0.05). The pain was rapidly alleviated in both groups on days 2 and 3. On days 1 and 2, the corneal fluorescein sodium staining scores in the TG-CXL group (4.15±0.83 and 2.21±0.60, respectively) were significantly higher than those in the TE-CXL group (1.76±0.56 and 0.85±0.51, respectively, P<0.001), while there was no significant difference between the two groups at day3 (P=0.184). The UCVA and BCVA of the TG-CXL group at 3, 6, and 12 months after surgery were significantly improved when compared with the baseline. At 3, 6, and 12 months, the BCVA (LogMAR) of the TG-CXL group (0.21±0.15, 0.22±0.16, and 0.22±0.16, respectively) were significantly improved when compared with those of the TE-CXL group(0.32±0.15, 0.34±0.15, and 0.36±0.16, respectively, P<0.01). However, there was no significant difference in UCVA between groups at any time point after surgery (P>0.05). The spherical and cylindrical power values of the TG-CXL group were improved when compared with the baseline (P<0.05). However, no significant difference in spherical power values was found between the two groups at any time point after surgery (P>0.05). Meanwhile, there were significant differences in cylindrical power values between the two groups at 6 and 12 months after surgery (P<0.05). The Kmax in the TG-CXL group was improved at all of the time points after surgery when compared with the baseline (P<0.001), while no significant difference in Kmax was found at any time point after surgery in the TE-CXL group when compared with the baseline (P>0.05). At 6 and 12 months after surgery, the Kmax values in the TG-CXL group were significantly lower than the TE-CXL group (P<0.05). No significant differences were found in flat keratomety, steep keratometry, the minimal thickness of the cornea, endothelial cell density, and intraocular pressure between the two groups at any time point after surgery (P>0.05). Within one month after surgery, optical coherence tomography revealed the increased density in the anterior stroma in both groups. In most patients in the TG-CXL group, a demarcation line was visible in the central and para-central corneal stroma, representing a clear and continuous, high-signal arc-shaped linear structure, which was deeper in the central cornea than the para-central cornea. In contrast, a demarcation line, fuzzy and focally discontinuous, was visible only in a few patients in the TE-CXL group, with an almost uniform depth in the central and the para-central cornea. Confocal microscopy demonstrated an apparent mesh-like cross-linked collagen structure in the superficial and intermediate corneal stroma at all time points after surgery in the TG-CXL group, with thickening stromal collagen fibers and an increased number of interconnections. In contrast, the mesh-like structure and number of interconnections in the superficial corneal stroma were significantly reduced at 12 months after surgery in the TE-CXL group, with no cross-linking structure in the intermediate corneal stroma at any time point after surgery. No serious complications such as corneal infection, sterile corneal ulcer, and persistent epithelial defect were observed in both groups during the follow-up of 12 months. Conclusions: The TG-CXL procedure by sequential irradiation in two different diameters with ultraviolet A light was effective and safe in the management of progressive keratoconus in adults, achieving significant refractive improvement. This might be a good technical alternative for refractive corneal cross-linking surgery.

Biaxial hyperelastic and anisotropic behaviors of the corneal anterior central stroma along the preferential fibril orientations. Part I: Measurement and calibration of personalized stress-strain curves

Lacking specimens is the biggest limitation of studying the mechanical behaviors of human corneal. Extracting stress-strain curves is the crucial step in investigating hyperelastic and anisotropic properties of human cornea. 15 human corneal specimens extracted from the small incision lenticule extraction (SMILE) surgery were applied in this study. To accurately measure the personalized true stress-strain curve using corneal lenticules, the digital image correlation (DIC) method and finite element method were used to calibrate the stress and the strain of the biaxial extension test. The hyperelastic load-displacement curves obtained from the biaxial extension test were performed in preferential fibril orientations, which are arranged along the nasal-temporal (NT) and the superior-inferior (SI) directions within the anterior central stroma. The displacement and strain fields were accurately calibrated and calculated using the digital image correlation (DIC) method. A conversion equation was given to convert the effective engineering strain to the true strain. The stress field distribution, which was simulated using the finite element method, was verified. Based on this, the effective nominal stress with personalized characteristics was calibrated. The personalized stress-strain curves containing individual characteristic, like diopter and anterior surface curvature, was accurately measured in this study. These results provide an experimental method using biaxial tensile test with corneal lenticules. It is the foundation for investigating the hyperelasticity and anisotropy of the central anterior stroma of human cornea.

Mini-Review: Clinical Features and Management of Granular Corneal Dystrophy Type 2.

Granular corneal dystrophy type 2 (GCD2) is an autosomal dominant corneal stromal dystrophy that is caused by p.Arg124His mutation of transforming growth factor β induced (TGFBI) gene. It is characterized by well demarcated granular shaped opacities in central anterior stroma and as the disease progresses, extrusion of the deposits results in ocular pain due to corneal epithelial erosion. Also, diffuse corneal haze which appears late, causes decrease in visual acuity. The prevalence of GCD2 is high in East Asia including Korea. Homozygous patients show a severe phenotype from an early age, and the heterozygote phenotype varies among patients, depending on several types of compound heterozygous TGFBI mutations. In the initial stage, conservative treatments such as artificial tears, antibiotic eye drops, and bandage contact lenses are used to treat corneal erosion. Different surgical methods are used depending on the depth and extent of the stromal deposits. Phototherapeutic keratectomy removes anterior opacities and is advantageous in terms of its applicability and repeatability. For deeper lesions, deep anterior lamellar keratoplasty can be used as the endothelial layer is not always affected. Recurrence following these treatments are reported within a wide range of rates in different studies due to varying definition of recurrence and follow-up period. In patients who have undergone corneal laser vision-correction surgeries such as photorefractive keratectomy, LASEK, or LASIK including SMILE surgery, corneal opacity exacerbates rapidly with severe deterioration of visual acuity. Further investigations on new treatments of GCD2 are necessary.

Rapamycin inhibits corneal inflammatory response and neovascularization in a mouse model of corneal alkali burn

Alkali burn-induced corneal injury often causes inflammation and neovascularization and leads to compromised vision. We previously reported that rapamycin ameliorated corneal injury after alkali burns by methylation modification. In this study, we aimed to investigate the rapamycin-medicated mechanism against corneal inflammation and neovascularization. Our data showed that alkali burn could induce a range of different inflammatory response, including a stark upregulation of pro-inflammatory factor expression and an increase in the infiltration of myeloperoxidase- and F4/80-positive cells from the corneal limbus to the central stroma. Rapamycin effectively downregulated the mRNA expression levels of tumor necrosis factor-alpha (TNF-α), interleukin-1beta (IL-1β), toll-like receptor 4 (TLR4), nucleotide binding oligomerization domain-like receptors (NLR) family pyrin domain-containing 3 (NLRP3), and Caspase-1, and suppressed the infiltration of neutrophils and macrophages. Inflammation-related angiogenesis mediated by matrix metalloproteinase-2 (MMP-2) and rapamycin restrained this process by inhibiting the TNF-α upregulation in burned corneas of mice. Rapamycin also restrained corneal alkali burn-induced inflammation by regulating HIF-1α/VEGF-mediated angiogenesis and the serum cytokines TNF-α, IL-6, Interferon-gamma (IFN-γ) and granulocyte-macrophage colony-stimulating factor (GM-CSF). The findings of this study indicated rapamycin may reduce inflammation-associated infiltration of inflammatory cells, shape the expression of cytokines, and balance the regulation of MMP-2 and HIF-1α-mediated inflammation and angiogenesis by suppressing mTOR activation in corneal wound healing induced by an alkali injury. It offered novel insights relevant for a potent drug for treating corneal alkali burn.

Biaxial hyperelastic and anisotropic behaviors of the corneal anterior central stroma along the preferential fibril orientations. Part II: Quantitative computational analysis of mechanical response of stromal components

To study the hyperelastic and anisotropic behaviors of the central anterior stroma for patients with myopia, 40 corneal stromal specimens extracted after small incision lenticule extraction (SMILE) surgery were used in the biaxial extension test along two preferential fibril orientations. An improved collagen fibril crimping constitutive model with a specific physical meaning was proposed to analyze the hyperelasticity and anisotropy of the stroma. The effective elastic modulus of the two families of preferentially oriented collagen fibrils and the stiffness of the non-collagenous matrix along all three directions were compared according to the specific physical meaning of the parameters. Anisotropic behavior was found in the hyperelastic properties of the corneal anterior central stroma in the preferential fibril orientations. The stiffness of non-collagenous matrix is significantly larger in the optical axis direction than in the nasal-temporal (NT) and superior-inferior (SI) directions. Moreover, individual differences between males and females slightly impact on hyperelastic and anisotropic behaviors. The differences of these behaviors were significant in the comparison of the left and right eyes. These results have a guiding significance for the accurate design of surgical plans for refractive surgery according to a patient's condition and have a driving value for the further exploration of the biomechanical properties of the whole cornea.

Standardization of corneal alkali burn methodology in rabbits

Alkali burns are one of the most common injuries used in corneal wound healing studies. Investigators have used different conditions to produce corneal alkali injuries that have varied in sodium hydroxide concentration, application methods, and duration of exposure. A critical factor in the subsequent corneal healing responses, including myofibroblast generation and fibrosis localization, is whether, or not, Descemet's membrane and the endothelium are injured during the initial exposure. After exposures that produce injuries confined to the epithelium and stroma, anterior stromal myofibroblasts and fibrosis are typical, with sparing of the posterior stroma. However, if there is also injury to Descemet's membrane and the endothelium, then myofibroblast generation and fibrosis is noted full corneal thickness, with predilection to the most anterior and most posterior stroma and a tendency for relative sparring of the central stroma that is likely related to the availability of TGF beta from the tears, epithelium, and the aqueous humor. A method is described where a 5 mm diameter circle of Whatman #1 filter paper wetted with only 30 μL of alkali solution is applied for 15 s prior to profuse irrigation in rabbit corneas. When 0.6N, or lower, NaOH is used, then the injury, myofibroblasts, and fibrosis generation are limited to the epithelium and stroma. Use of 0.75N NaOH triggers injury to Descemet's membrane and the corneal endothelium with fibrosis throughout the stroma, but rare corneal neovascularization (CNV) and persistent epithelial defects (PED). Use of 1N NaOH with this method produces greater stromal fibrosis and increased likelihood that CNV and PED will occur in individual corneas.

Treatment of 3D In Vitro Tumoroids of Ovarian Cancer Using Photochemical Internalisation as a Drug Delivery Method

Photochemical internalisation (PCI) is a means of achieving spatio-temporal control of cytosolic drug delivery using sub-lethal photodynamic therapy (PDT), with a photosensitiser that can be activated by non-ionising visible light. Various 3D models including those developed at our laboratory, where spheroids are grown in a compressed collagen matrix, have been used for studying anti-cancer drug effects. However, the use of a more biomimetic tumouroid model which consists of a relatively hypoxic central cancer mass surrounded by its microenvironment (stroma) has not yet been explored in either toxicity or phototoxicity studies involving PCI. Here, we examined the efficacy of PCI using a porphyrin photosensitiser and a cytotoxin (Saporin) on ovarian cancer tumouroids, with HEY ovarian cancer cells in the central cancer compartment, and HDF fibroblast cells and HUVEC endothelial cells in the surrounding stromal compartment. The efficacy was compared to tumouroids treated with either Saporin or PDT alone, or no treatment. PCI treatment was shown to be effective in the tumouroids (determined through viability assays and imaging) and caused a considerable decrease in the viability of cancer cells both within the central cancer mass and those which had migrated into the stroma, as well as a reduction in the cell density of surrounding HUVEC and HDFs. Post-treatment, the mean distance of stromal invasion by cancer cells from the original cancer mass following treatment with Saporin alone was 730 μm vs. 125 μm for PCI. PDT was also effective at reducing viability in the central cancer mass and stroma but required a higher photosensitiser dose and light dose than PCI. Tumouroids, as tissue mimics, are suitable models for interrogating multicellular events following pharmacological assault.

Corneal stroma densitometry evolution in a clinical model of cellular therapy for advanced keratoconus

AbstractPurpose: To report the corneal stromal densitometry (CD) evolution studied by Scheimpflug tomography, anterior segment optical coherence tomography (AS‐OCT), and confocal microscopy changes, in keratoconus patients included in a clinical experience of advanced cell therapy using autologous humans adipose‐derived adult stem cells (ADASCs), and corneal decellularized or ADASCs‐recellularized human donor corneal laminas in advanced keratoconus.Methods: Interventional prospective, consecutive, randomized, comparative series of cases. Fourteen keratoconic patients were randomly distributed into three groups for three types of surgical interventions: group 1 (G‐1), autologous ADASCs implantation (n = 5); group 2 (G‐2), decellularized human corneal stroma (n = 5); and, group 3 (G‐3), autologous ADASCs + decellularized human corneal stroma (n = 4). Participants were assessed with Scheimpflug‐based Oculus Pentacam CD module, AS‐OCT (Visante, Carl Zeiss), and confocal microscopy (HRT3 RCM Heidelberg).Results: The central and total CD were statistically significantly higher in G‐2 compared with G‐1, and G‐3 compared with G‐1 at the studied annular zones centered on the corneal apex (0–2 mm, 2–6 mm, and 6–10 mm). There was statistical significance higher in G‐3 compared with G‐2 at the central corneal stroma at (0–2 mm, 2‐6 mm). The confocal microscopy findings, as well as the AS‐OCT reflected the densitometry changes.Conclusions: The intrastromal implantation of ADASCs produced very subtle changes in CD at the level of the central corneal stroma. However, the intrastromal implantation of decellularized corneal laminas increases it slightly, but with lower values than the implantation of recellularized laminas with ADASCs.

Extrapelvic "Uterus Like Mass" Following Laparoscopic Morcellation Hysterectomy - a Consequence of Iatrogenic Implantation?

Uterus-like mass is a rare form of endometriosis, which shows striking structural similarity to the normal uterus. Formation of a mass lesion raises clinical concern for malignancy, and pathologic examination is necessary for accurate diagnosis. We describe herein, a middle aged woman who presented with a mesenteric mass six years post hysterectomy, which was initially suspected to be a gastrointestinal stromal tumor. The resected was specimen was grossly pear shaped with microscopy showing a central endometrial glands and stroma lined cavity, surrounded by a thick muscular wall reminiscent of uterine myometrium. Histogenesis of this entity is unclear, and several theories are proposed regarding the etiology, including congenital anomaly theory, metaplasia and heterotopia theories. Our clinical scenario developed a few years after uterine morcellation, indicating a possibility of another "iatrogenic implantation" theory behind the pathogenesis of this rare lesion.

Abstract 6130: Comprehensive genomic and transcriptomic profiling of acral lentiginous melanoma

Abstract Background: Acral lentiginous melanoma (ALM) is a rare melanoma subtype found on the palms, soles and nailbeds. Outcomes are poor for patients with advanced ALM, and novel treatment approaches are needed. Here, we seek to explore the global genomic and transcriptomic landscape of ALM. Methods: A total of 699 primary CM (non-ALM cutaneous melanoma) and 18 primary ALM samples underwent next generation sequencing of DNA (592 Gene Panel, NextSeq, or WES, NovaSeq), and whole transcriptome sequencing (NovaSeq, WTS). Wilcoxon, Fisher’s exact test were used to determine statistical significance (displayed as p value without and q value with multi comparison correction). xCell, HLA subtyping, neoantigen load (HBA: high binding affinity; IBA: intermediate binding affinity; LBA: low binding affinity), Interferon gamma score (IFNγ), MAPK pathway activity score (MPAS), and Innate anti-PD-1 Resistance score (IPRES) were calculated by mRNA expression. Global differentially regulated genes were assessed via limma R package (C: log fold change). Results: The most common alterations in ALM included NRAS (22.2%), NF1 (20.0%), BRAF (11.1%) and CDKN2A (11.1%) mutations, and EMSY (22.2%), ELL (11.1%), MAML2 (11.1%), MRE11(11.1%) and PIK3R2 (11.1%) amplifications. ALM had lower TMB (1.5 v 9 Mut/Mb, q&amp;lt;.0001), lower rates of TERT (0 v 66.7%, q&amp;lt;.01) and a trend towards lower BRAF (11.1 v 39.8%, p&amp;lt;.05) mutations, compared to CM. Neoantigen load was lower in ALM compared to CM, regardless of MHC binding affinity (HBA: 1 vs 4, q &amp;lt;.01; IBA: 2 vs 7, q &amp;lt;.001; LBA: 7 vs 18, q &amp;lt;.001). HLA-G RNA expression was upregulated in ALM with respect to CM (C = 1.14, q &amp;lt;.001). ALM showed less CD4+ T cell Th1 (C = -0.8, p &amp;lt;.05), B cell plasma (C = -1.8, p&amp;lt;.05), and γδ T cells (C = -5.9, p&amp;lt;.05), but more CD4+ T cell central memory cell (C = 9.7, p&amp;lt;.05), stroma score (C = 1.7, p&amp;lt;.05), and endothelial cells (C = 1.7, p&amp;lt;.05), versus CM. There was a trend towards lower IFNγ in ALM (-0.4 vs -0.3, p = .1), but no difference in IPRES, compared to CM (-0.09 vs 0.1, p=.9). MPAS scores were lower for ALM compared to CM (-1.6 vs -0.4, q&amp;lt;.001), even when stratifying by BRAF (q&amp;lt;.05) or NF1 (q&amp;lt;.05) status, but not NRAS (p = .22). Pathways related to keratinization (p &amp;lt;.0001) and amyloid fiber formation (p&amp;lt;.0001) were enriched in ALM, due to overexpression of KRT16 (C = 3.5, q &amp;lt;.01), KRT6B (C = 3.4, q &amp;lt;.01), and KRT17 (C = 3.2, q &amp;lt;.05), among others. Conclusion: ALM has distinct immunologic features, including upregulation of HLA-G, as well as lower MAPK activation in ALM, compared to CM, highlighting the need for novel therapeutic approaches in the treatment of this rare subtype. Citation Format: Gino K. In, Jun Yin, Phillip Walker, Justin Moser, Joanne Xiu, Kelsey Poorman, Geoffery T. Gibney, Matthew Oberley, Thuy Phung, Leonel F. Hernandez-Aya, Jose Lutzky, Wolfgang Michael Korn, Michael B. Atkins. Comprehensive genomic and transcriptomic profiling of acral lentiginous melanoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 6130.

Evaluation of ocular surface epithelial and stromal thicknesses in psoriasis using anterior segment optical coherence tomography.

To evaluate the epithelial and stromal thicknesses of conjunctiva and cornea in psoriatic patients with anterior segment optical coherence tomography (AS-OCT), METHODS: In this cross-sectional study, 61 patients with psoriasis and 42 age-matched, healthy individuals were enrolled. The epithelial and stromal thicknesses of both inferotemporal bulbar conjunctiva and central cornea were measured using AS-OCT. Both the tear breakup time and Schirmer-1 test values were significantly lower in the psoriasis group compared with the controls (p < 0.05). The epithelial thickness of conjunctiva and cornea did not differ between psoriasis and control groups (p > 0.05). The central corneal stroma was significantly thicker in the psoriasis group (p = 0.04). PASI was positively correlated with the thickness of central cornea stroma (r = 0.442, p = 0.006) in the nail psoriasis group. Psoriasis is not associated with altered epithelial thicknesses of the cornea and conjunctiva. It is accompanied by the stromal thickening of the cornea without conjunctival stromal involvement.

Indirectly assessing changes in corneal properties with OCT speckle after crosslinking in porcine eyes

The aim of this study was to assess the effect of the standard crosslinking (CXL) procedure on corneal properties and subsequent changes in collagen bonds formation using optical coherence tomography (OCT) corneal speckle statistics and vibrational spectroscopy.Porcine eyes with intact corneal epithelium were randomly selected to one of the four study groups: (1) untreated eyes moistened with phosphate-buffered saline (PBS); (2) eyes after the epithelial debridement and riboflavin application; (3) eyes after CXL procedure according to the Dresden protocol; and (4) eyes after corneal epithelial debridement, regularly moistened with PBS. Before and after this selection, each eyeball was subjected to the constant intraocular pressure of 20 mmHg. Then, ocular biometry was performed and the central cornea was imaged using spectral-domain OCT. Following this, a nonparametric approach to speckle modeling (the Contrast Ratio (CR)) was utilized within the region of interest for each B-scan covering the central corneal stroma. To verify whether the CXL performed ex-vivo results in formation of new bonds in the cornea, Fourier Transform Infrared Attenuated Total Reflectance (ATR-FTIR) spectra of dried corneas, dissected from examined eyeballs, were collected and analyzed.Corneal epithelium removal alone or with the riboflavin application leads to a statistically significant decrease in the CR median value (the Wilcoxon signed-rank test, p < 0.05). However, the most pronounced change in CR median value, which decreases with the increased number of scatterers, was shown after the complete CXL procedure including riboflavin soaking and UVA irradiation (the Wilcoxon signed-rank test, p = 0.004). Analysis of ATR-FTIR spectra revealed influence of UVA irradiation on collagen matrix. The study has shown the increased dehydration accompanied by almost no alteration of collagen native triple-helical structure. Significant changes have been observed for bands related to collagen crosslinks. Specifically, the predominant changes occurred in the sugar region from 1150 to 975 cm−1, as well as in the absorbance of carbonyl groups. Furthermore, the ratio of two Amide I components at approximately 1660 cm−1 and 1675 cm−1 decreased after UVA irradiation. Together, these results provided the evidence for the creation of new corneal crosslinks.In conclusion, this study clearly indicates that the UVA exposure causes the substantial difference in optical scattering occurring in corneal stroma as a result of the induced biochemical changes at the molecular level in this tissue assessed with ATR-FTIR. The proposed speckle-based methodology brings a new insight into the development of OCT technology useful in an indirect assessment of some collagen changes.

Cytological Diagnosis of Pancreatic Solid-Pseudopapillary Neoplasm: A Single-Institution Community Practice Experience.

Introduction. Pancreatic solid-pseudopapillary neoplasm (SPN) is a rare tumor that typically occurs in young females. Although a cytological diagnosis may be easily made in this age group when there are typical features, atypical clinical presentations and unusual cytological features may make this a challenging diagnosis. We present our single-institution experience in a cohort of these tumors, outlining both typical and atypical features. Awareness of unusual clinical and cytological features can help to avoid pitfalls during diagnosis. Methods. We performed a review of all cases of pancreatic SPNs diagnosed over a 15-year period (January 2007 to December 2021). Detailed cytological, clinical, and follow-up histological features were presented and analyzed. Results. Twenty-two cases of SPN were diagnosed at our institution during this 15-year period. Patients ranged from 12 to 73 years of age (mean 33 y, median 26 y) and included 19 females and 3 males. Seventeen patients had cytological material, and fourteen were diagnosed by EUS-FNA. Typical cytological features included papillary clusters with central capillaries, myxoid stroma, monomorphism, cercariform cells, and hyaline globules. Atypical or unusual cytological features that were seen in a few cases were multinucleated giant cells, clear cells, and/or foamy macrophages. A few cases showed features that were similar to pancreatic neuroendocrine tumors (PanNETs). Tumor cells were always positive for β-catenin, CD10, CD56, cyclin-D1, progesterone receptor (PR), and vimentin by immunohistochemistry. They were always negative for chromogranin. Pancytokeratin and synaptophysin stains were positive in 9% and 46% of cases evaluated, respectively. All cases had histological confirmation on resection. The median follow-up duration was 69 months (a range of 2–177 months), with only three cases lost to follow-up. No recurrence or metastasis was identified. Conclusions. We present our experience with cytological diagnoses of SPN in a well-characterized cohort of 22 patients with histological correlation and follow-up data. These tumors occur over a wide range and show varied cytological features. SPNs can be confidently diagnosed on limited cytological material, with limited panel immunohistochemistry aiding diagnosis in atypical cases. Recognizing the associated degenerative changes is crucial in avoiding a misdiagnosis.

Mediators of the Effect of Corneal Cross-Linking on Visual Acuity for Fungal Ulcers: A Prespecified Secondary Analysis From the Cross-Linking-Assisted Infection Reduction Trial.

The purpose of this study was to determine whether astigmatism or corneal scarring is mediating the reduced visual acuity among patients with fungal keratitis randomized to corneal cross-linking (CXL). This was a prespecified exploratory outcome from an outcome-masked, 2 × 2 factorial design, randomized controlled clinical trial. Consecutive patients presented with moderate vision loss from a smear-positive fungal ulcer at Aravind Eye Hospital, Madurai, India. Study eyes were randomized to one of 4 treatment combinations using an adaptive randomization protocol. The treatment arms included (1) topical natamycin 5% alone, (2) topical natamycin 5% plus CXL, (3) topical amphotericin B 0.15% alone, and (4) topical amphotericin 0.15% plus CXL. Best spectacle-corrected visual acuity (BSCVA), contact lens over-refraction, and scar size and depth as measured by a masked study ophthalmologist using a standardized protocol were recorded at 3 months. Pentacam Scheimpflug imaging was also obtained at 3 months. BSCVA and contact lens over-refraction, infiltrate and/or scar size and depth, total astigmatism of the front and back of the cornea, total lower-order and higher-order aberrations of the anterior and posterior cornea, and total densitometry of the anterior, central, and posterior stroma were recorded. We performed a mediation analysis looking at the proportion of the effect of CXL on BSCVA that was mediated through scar size, scar depth, astigmatism and density. BSCVA at 3 months was available for 99 of 111 patients (89%) who had a mean of 0.82-LogMAR (SD 0.68). Three-month infiltrate and/or scar size ( P < 0.001), depth ( P < 0.001), and densitometry ( P = 0.001) were statistically significant predictors of 3-month BSCVA. Astigmatism seemed to mediate 23% of the effect of CXL on BSCVA, whereas scar size mediated 23%, scar depth 17%, and densitometry 7%. Corneal scarring and astigmatism are mediators of worse visual acuity after cross-linking in fungal keratitis. Corneal densitometry may be a helpful cornea-specific variable for clinicians and researchers in determining the effect of corneal scarring on visual acuity in specific patients and as an objective study outcome. NCT02570321.

A unique pre‐endothelial layer at the posterior peripheral cornea: ultra‐structural study

AbstractPurposeTo investigate the ultrastructure of a unique pre‐endothelial layer (PENL) of the posterior peripheral cornea and compare their fibers to those of the limbus and sclera.MethodsTen anonymous‐donor human sclera–corneal rings (leftover after corneal transplants) were processed for electron microscopy. Semi‐thin sections were examined using an Olympus BX53 microscope, and ultrathin sections were studied using a JOEL 1400 transmission electron microscope.ResultsA unique pre‐endothelial layer (PENL) was identified at the posterior peripheral cornea a radial distance of 70 µm – 638 µm, from the Descemet’s membrane endpoint (DME). At 272 µm distance from the DME, the posterior pre‐limbal cornea contained 5 layers; basement membrane (BM), pre‐Descemet’s layer (PDL), Descemet’s layer (DM), and a pre‐endothelial layer (PENL) between the DM and endothelium (EN). As the DM runs towards the central stroma, the PENL thins out gradually and disappears at a distance of 638 µm from DME. The layer contained an electron‐dense sheath with periodic structures (narrow‐spacing fibers), wide‐spacing fibers, and numerous microfibrils. The typical elastic fibers were composed of an elastic core surrounded by microfibrils. These were present in sclera and limbus but were not observed in the PENL.ConclusionsThe present study revealed the existence of a new acellular PENL, and it can be considered as another layer of the pre‐limbal peripheral posterior cornea. Knowledge of the PENL layer may help with understanding the pathology of endothelial dystrophies and pre‐DM dystrophies. PENL fibers were similar in structure to the fibers of trabecular meshwork described previously.