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Purpose: This study aimed to compare four depths of manual dissection for the preparation of Descemet stripping endothelial keratoplasty lamellae. Methods: Eye bank corneas were randomized into four groups according to dissection depths: Pachy-100 (incision depth = central corneal thickness-safety margin of 100 µm), Pachy-50 (safety margin of 50 µm), Pachy-0 (no safety margin), and Pachy+50 (incision depth = central corneal thickness + 50 µm). All endothelial lamellae were prepared using a standardized method of manual dissection (Pachy-DSEK). The central, paracentral (3.0-mm zone), and peripheral (6.0-mm zone) lamella thicknesses and incision depths were measured by optical coherence tomography. The 3.0-mm and 6.0-mm zone central-to-peripheral thickness ratios were calculated. Results: Endothelial perforation occurred only in the Pachy+50 group (n=3, 30%). Central lamella's thickness in Pachy-100, Pachy-50, Pachy-0, and Pachy+50 groups measured 185 ± 42 µm, 122 ± 29 µm, 114 ± 29 µm, and 58 ± 31 µm, respectively (p<0.001). The overall 3.0- and 6.0-mm C/P ratios were 0.97 ± 0.06 and 0.92 ± 0.14, respectively. Preoperative donor characteristics were not correlated with most thickness outcomes. The planned incision depth correlated significantly with most lamella's thickness parameters (p<0.001). The overall thickness of the lamella negatively correlated with the planned incision depth (p<0.001, r=-0.580). The best outcome was found in the Pachy-0 group, as 75% of the lamellae measured <130 µm and there was no endothelial perforation. Conclusions: By using a standardized method of dissection, most manually prepared lamellae presented a planar shape. Setting the incision depth to the central corneal thickness did not result in endothelial perforation and a high percentage of ultrathin lamellae was achieved. [ABSTRACT FROM AUTHOR]

PURPOSE: The purpose of this study was to evaluate the changes in corneal endothelial cell density (CECD) occurring after cataract phacoemulsification surgery and identify factors associated with cell loss. MATERIALS AND METHODS: This was a retrospective study involving patients who underwent cataract phacoemulsification surgery between January 1, 2018, and December 31, 2018, at two private hospitals. Demographic data and biometric parameters were obtained preoperatively. Ultrasound metrics were recorded for each operation, including total on time (TOT), total equivalent power in position 3, and cumulative dissipated energy (CDE). Using corneal specular microscopy, CECD was measured preoperatively and postoperatively at 12, 24, and 36 months. Factors associated with decreased CECD were identified. RESULTS: This study included 223 eyes of 133 patients. The mean CECD was 2530.03 ± 285.42 cells/mm2 preoperatively and significantly decreased to 2364.22 ± 386.98 cells/mm2 at 12 months (P < 0.001), 2292.32 ± 319.72 cells/mm2 at 24 months (P < 0.001), and 2242.85 ± 363.65 cells/mm2 at 36 months (P < 0.001). The amount of cell loss was associated with age, gender, preoperative CECD, preoperative anterior chamber depth, lens thickness, TOT, and CDE. Using multivariate analysis, age, preoperative CECD, and TOT were identified as independent predictors for CECD loss 12 months after surgery. CONCLUSION: The greatest decrease in CECD occurred during the first year after cataract surgery, and the amount of cell loss was influenced by both baseline patient characteristics and ultrasound metrics. Longer-term prospective studies in a larger cohort may yield more information. [ABSTRACT FROM AUTHOR]

PURPOSE: The inducible Cre-ERT2 recombinase system allows for temporal control of gene targeting, and it is useful to studying adult function of genes that have critical developmental roles. The Zeb1flox/flox: UBC-CreERT2 mouse was generated to conditionally target Zeb1 to investigate its role in mesenchymal transition in the mouse corneal endothelium in vivo. MATERIALS AND METHODS: Hemizygous UBC-CreERT2 mice were crossed with homozygous mice harboring loxP-flanked Zeb1 alleles (Zeb1flox/flox) to generate the Zeb1flox/flox: UBC-CreERT2 mouse. 4-hydroxytamoxifen (4-OHT) exposure leads to excision of exon 6 of Zeb1, resulting in a loss function allele in the Zeb1flox/flox: UBC-CreERT2 mouse. Intracameral 4-OHT injection further isolates Zeb1 targeting to the anterior chamber. Mesenchymal transition and induction of Zeb1 expression in the corneal endothelium was achieved using FGF2 in ex vivo organ culture. Gene expression was analyzed by semi-quantitative reverse transcription-polymerase chain reaction and by immunoblotting in the mouse corneal endothelium in vivo. RESULTS: Following Cre-mediated targeting of Zeb1 by intracameral 4-OHT injection in Zeb1flox/flox: UBC-CreERT2 mice, FGF2 treatment in ex vivo organ culture resulted in abrogation of Zeb1 mRNA and protein expression in the corneal endothelium. CONCLUSION: The data show Zeb1, a critical mediator of fibrosis in corneal endothelial mesenchymal transition, can be targeted by intracameral injection of 4-OHT in the mouse corneal endothelium in vivo. These results suggest that genes with critical developmental roles can be targeted at a specific time in the corneal endothelium to study its role in adult disease using an inducible Cre-Lox strategy. [ABSTRACT FROM AUTHOR]

To investigate subclinical corneal changes using corneal topography in the evaluation of corneal curvature and specular microscopy in the evaluation of the endothelial layer after mild coronavirus disease 2019 (COVID-19). In this prospective study, 112 eyes of 56 individuals with mild COVID-19 who recovered were investigated. Mean cell density (CD), mean coefficient of variation (CV), mean percentage of hexagonal cells, mean cell area (AVG), and central corneal thickness (CCT) were recorded from specular microscopy. K readings, including simulated keratometry flat (K1), simulated keratometry steep (K2), average keratometry (Kmean) and maximum keratometry (Kmax), pachymetric measurement and central corneal thickness (CCT), corneal volume (CV), topographic astigmatism (TA), curvature asymmetry front (CAf) and curvature asymmetry back (CAb) were recorded from corneal topography. Best corrected visual acuity (BCVA), spherical equivalant and biometric measurements were recorded. The mean time interval between examinations before and after COVID-19 infection was approximately one year. Analysis of specular microscopy data showed a statistically significant change in all endothelial cell parameters (p <0.001) except the cell count (p = 0.358). The median (range) endothelial cell density (ECD) value was significantly lower after COVID-19 at 2356 (2289–2400) than before, when it was 2596 (2545–2640). Furthermore, CCT values showed a significant increase (p <0.001). The topographic values including K2, Kmax and TA and biometric measurements did not change. The Spherical Equivalant (SE) values showed significant myopic progression after COVID-19 (p <0.001). Endothelial parameters changed more than the changes in corneal curvature and ocular biometric measurements after mild COVID-19. The decrease in endothelial cell number and hexagonality and increase in polymorphism after COVID-19 were striking. [ABSTRACT FROM AUTHOR]

Pars plana vitrectomy is currently the most common technique used in retinal surgery. Although primarily involving the posterior segment of the eye it also affects the anterior segment. As this is a less published topic, the aim of this paper was to review the literature on changes in the anterior segment after uncomplicated pars plana vitrectomy using data based literature search. The conclusions are that even in otherwise ophthalmologically healthy patients, complications may occur in the anterior segment. Surgeons need to pay utmost attention in glaucoma patients and in those with endothelial insufficiency who are at highest risk of complications. He/she must also correctly plan a potential cataract surgery if not already done earlier. From the literature, most of the changes in the anterior segment after uncomplicated PPV are found to be temporary. [ABSTRACT FROM AUTHOR]

AIM: The aim of this study was to study the effect of neodymium-doped yttrium aluminum garnet (Nd:YAG) laser iridotomy on corneal endothelial cell count in patients with subacute angle closure using specular microscope. MATERIALS AND METHODS: In this prospective study, 50 cases of narrow-angle Grade 1 and Grade 2 (Shaffer gonioscopic grading) visiting the Regional Institute of Ophthalmology, Government Medical College, Amritsar underwent Nd:YAG laser peripheral iridotomy. After obtaining informed written consent, specular microscopy was performed before and after iridotomy at 1 week, 1 month, 3rd month, and at 6th-month follow-up visits. Central, nasal, and temporal endothelial cell counts were evaluated through noncontact specular microscopy. RESULTS: The mean participant age was 51.52 ± 7.9 years, and majority of the participants were females (76%). The mean IOP before the laser was 19.25 ± 1.914 mmHg and it varied from 18.50 ± 1.647 to 18.25 ± 1.699 mmHg (day 1, p = 0.06 and at 6 months, p = 0.04) following laser procedure. The mean corneal endothelial cell count at superotemporal site before laser peripheral iridotomy was 2844 ± 260, and this value decreased to 2807 ± 263, 2699 ± 267, 2656 ± 270, and 2591 ± 275 cells/mm2 at postiridotomy, 1, 3, and 6 months' follow-up visits, respectively; these differences were statistically significant (p < 0.05). The mean total energy required to produce iridotomy was 14.88 ± 6.71 mJ, ranging from 5 to 37 mJ. The linear regression analysis indicated no statistical correlation between change in endothelial cell count at the treated site and total mean energy used. No significant difference was found between preiridotomy and postiridotomy corneal thickness at any site. CONCLUSION: This study demonstrated a significant endothelial cell loss at the treated site in 6 months' follow-up and suggested that Nd:YAG laser iridotomy may pose hazard to the corneal endothelium, although corneal decompensation at the treated site or as a whole was not seen. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • A fully automatic approach for corneal endothelial cells segmentation is proposed. • The method is dedicated to endothelium microscopic images. • It combines a neural network, adaptive thresholding and iterative morphological processing. • The method was tested on three datasets of corneal endothelium microscopic images. • The error of cell number determination is below 7%. Abstract The structure of the corneal endothelial cells can provide important information about the cornea health status. Particularly, parameters describing cell size and shape are important. However, these parameters are not widely used, because it requires segmentation of the cells from corneal endothelium images. Although several dedicated approaches exist, none of them is faultless. Therefore, this paper proposes a new approach to fully automatic segmentation of corneal endothelium images. The proposed approach combines a neural network which is thought to recognize pixels located at the cell boundaries, with postprocessing of the resulting boundary probability map. The postprocessing includes morphological reconstruction followed by coarse cell segmentation using local thresholding. The resulting cells are next separated from each other via iterative morphological opening. Finally, the region between cell bodies is skeletonized. The proposed method was tested on three publicly available corneal endothelium image datasets. The results were assessed against the ground truths and compared with the results provided by selected state-of-the-art methods. The resulting cell boundaries are well aligned with the ground truths. The mean absolute error of the determined cell number equals 6.78%, while the mean absolute error of cell size is at the level of 5.13%. Cell morphometric parameters were determined with the error of 5.69% for the coefficient of variation of cell side length and 11.64% for cell hexagonality. [ABSTRACT FROM AUTHOR]

Current solutions for corneal endothelial image segmentation use convolutional neural networks. However, their potential is not exploited due to the scarcity of labeled corneal endothelial data caused by an expensive cell delineation process. Therefore, this work proposes synthesizing cell edges and corresponding images using generative adversarial neural networks. To our knowledge, such work has not yet been reported in the context of corneal endothelial image segmentation. A two-step pipeline for synthesizing training patches is proposed. First, a custom mosaic generator creates a grid that mimics a binary map of endothelial cell edges. The synthetic cell edges are then input to the generative adversarial neural network, which is trained to generate corneal endothelial image patches from the corresponding edge labels. Finally, pairs of synthetic patches are used to train the patch-based U-Net model for corneal endothelial image segmentation. Experiments performed on three datasets of corneal endothelial images show that using purely synthetic data for U-Net training allows image segmentation with comparable accuracy to that obtained when using original images annotated by experts. Depending on the dataset, the segmentation quality decreases only from 1% to 4%. Our solution provides a cost-effective source of diverse training data for corneal endothelial image segmentation. Due to the simple graphical user interface wrapping the proposed solution, many users can easily obtain unlimited training data for corneal endothelial image segmentation and use it in various scenarios. [Display omitted] • A method for synthesizing patches of corneal endothelial images is proposed. • Synthetic patches are accompanied by the endothelial cell edges annotations. • The method comprises a mosaic generator and a generative adversarial neural network. • The U-Net model was trained on real and synthetic data and yields comparable results. • The method provides unlimited train data for corneal endothelial image segmentation. [ABSTRACT FROM AUTHOR]

Purpose To determine the age related changes in corneal morphological characteristics in normal healthy adult Pakistani population. Methods Four hundred and sixty-four eyes of 232 healthy volunteers with ages between 10 and 80 years of either gender were included. Corneal endothelial cell density (CED), morphology and central corneal thickness (CCT) were evaluated in each subject with non-contact specular microscope (SP-3000 P, Topcon Corporation, Japan) and average of three readings per eye was used for final analysis. All the findings including demographic data, and corneal parameters were endorsed on a pre-devised proforma. Results Mean age of study population was 39.52 ± 18.09 years with 123 (53%) males and 109 (47%) females. Mean CED of study population was 2722.67 ± 349.67 cells/mm 2 , while mean CCT was 505.72 ± 32.82 µm. Corneal morphological parameters among various age groups showed statistically significant difference in all parameters ( p < 0.01). Correlation statistics revealed that CED ( r = −0.497, p < 0.01), CCT ( r = −0.216, p < 0.01) and hexagonality ( r = −0.397, p < 0.01) decreased significantly with increasing age, while average cell size ( r = 0.492, p < 0.01) and CV of size ( r = 0.454, p < 0.01) increased with age. Conclusion This study showed that CED in Pakistani eyes was less than that reported in Chinese eyes, higher than Portuguese, Iranian and Indian eyes and comparable to the values in Turkish, Nigerian and Thai eyes. [ABSTRACT FROM AUTHOR]

• Non-contact specular microscopy was utilized in this study to detect differences in the corneal endothelium layer between active and inactive Graves' ophthalmopathy. • The corneal endothelial cell morphology in active Graves' ophthalmopathy differs from that of inactive Graves' ophthalmopathy. • To assess the active state of GO, the coefficient of variation (CV) and the standard deviation of cell area (SD) may be a practical, precise, and quantifiable technique. To investigate the possible corneal endothelial damage in Graves' ophthalmopathy (GO) and its relationship with GO activity. This cross-sectional study included 101 eyes of 55 patients with GO. Each eye was assigned a specific clinical activity score (CAS). Accordingly, they were classified as active (CAS ≥ 3) or inactive (CAS< 3). The corneal endothelium was measured using a non-contact specular microscope (Tomey EM-4000; Tomey Corp.). Endothelial cell density (ECD), average cell area (ACA), standard deviation of cell area (SD), coefficient of variation in cell area (CV), hexagonal cell ratio (HEX), and central corneal thickness (CCT) were recorded. Among the eyes included in the study, 71 had inactive GO and 30 had active GO. ACA and HEX levels were lower (p <0,001) and CV values were higher (p <0.001) in patients with GO than in healthy subjects. Corneal endothelial cell morphology was altered in active GO compared to inactive GO. The SD (p = 0,009) and CV (p <0,001) were significantly higher in active GO than in inactive GO. When the parameters examined were correlated with CAS, a statistically significant positive correlation was observed between proptosis (p = 0,036, r = 0,385) and CV (p = 0,001, r = 0,595). Our study confirmed that morphological changes occur in the corneal endothelium of patients with GO. CV and SD values, in conjunction with CAS, can be used as non-invasive and quantitative indices to examine the activity status of GO. The demonstration of endothelial changes even in GO eyes with low CAS may be considered an incentive to include non-contact specular microscopy in the routine clinical evaluation of all patients with GO. [ABSTRACT FROM AUTHOR]

Aim To reveal the changes of corneal endothelial characteristics with aging among Caucasian population. Methods Non-contact specular microscopy was performed in 564 eyes of 282 healthy Caucasian Turkish patients. Endothelial cell density (MCD), mean cell area (MCA), coefficient of variation (CV) in cell size, percentage of hexagonal cells, and central corneal thickness (CCT) were measured. Results The mean age was 42 ± 17.1 (6–85) years. The MCD of the population was 2732 ± 305 cell/mm 2 (range, 1904–3802 cell/mm 2 ). The MCA was 368 ± 41 m 2 (range, 263–522 m 2 ). The mean CV in cell size was 34 ± 7 (range, 25–68), the mean percentage of hexagonal cells was 46 ± 8% (range, 25–76%), and CCT was 513 ± 39 (range, 407–623). There was statistically significantly negative correlation ( p < 0.05) between age and cell density, hexagonality, and pachymetry. There was statistically significant correlation ( p < 0.05) between age and MCA. Conclusion We report the normal values of corneal endothelial characteristics in Caucasian Turkish eyes. Over the age of 20, the MCD of Caucasian eyes is more than the Indian and Iranian eyes and less than the Chinese eyes. Caucasian population’s cell density in under the age of 20 is 3101 ± 268 cell/mm 2 . [ABSTRACT FROM AUTHOR]

Copyright of Pesquisa Veterinaria Brasileira is the property of Colegio Brasileiro de Patologia Animal - CBPA and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Aim The human corneal endothelium is a monolayer of flat hexagonal cells. It is a nearly regular hexagonal tessellation during the first years of life, but with age, becomes less regular in shape and size. The aim is to evaluate geometrically the age of an endothelial mosaic. Material and methods Segmented endothelial mosaics of healthy subjects of different age groups are compared by morphological criteria. The mosaics are studied according to their age group (decades), their age and their location (center or mid-periphery of the cornea). The measures used are: the cell density, the Ripley's L function and the cell area and perimeter density. Results These measures point out the endothelial cell density decrease, the cell area, perimeter and diameter increase, the cell heterogeneity increase, and the differences between central and mid-peripheral cells increases with age. Conclusion These measures are able to characterize healthy mosaics. [ABSTRACT FROM AUTHOR]

Objectives: Non-contact specular microscopes (SM) have a very small field of observation (usually 0.1 mm 2 ). This constitutes a major limitation when accurate and extended assessment of the corneal endothelium is needed, for instance during clinical trials or difficult diagnosis. Previous contact SM had the advantage of a wide field thanks to the use of an applanating cone but none of the old commercial devices passed the stage of digitalization. This paper aims at upgrading a wide field contact SM with a digital camera and dedicated software in order to combine wide field with the advantages of non-contact SM. Materials and methods: The digital device was composed of an acquisition unit consisting in a contact Konan Specular SP5500 equipped with a digital camera Canon EOS 6D and a Linux-based computer. Image processing uses segmentation algorithms (Gestalt theory and watershed with markers). Results: The device acquired wide field (0.5 mm 2 ) highly contrasted images. The software provided cell boundaries and statistics: endothelial cell density, coefficient of variation of cell area and percentage of hexagonality. Contact SM images significantly increased the sampling of endothelial cells and consequently the reliability of endothelial quality analysis. Conclusion: The digital contact SM is not destined to compete with commercial non-contact SM but is an exceptional device for reference centers. It will allow obtaining accurate and reproducible endothelial qualification for specific studies. [ABSTRACT FROM AUTHOR]

• Corneal/lenticular optical density can be measured objectively by Scheimpflug imaging. • Corneal optical density was increased in children with intraocular inflammation. • Healthy/systemic inflammation groups had similar corneal/lenticular optical density. Corneal and lenticular optical properties are not well-documented in pediatric patients with inflammatory diseases. Here we aimed to evaluate corneal and lenticular optical density as well as corneal morphology in children with ocular and/or systemic inflammation by Scheimpflug imaging. Fifty-five eyes of 29 children with non-infectious uveitis, 56 eyes of 28 children with systemic inflammation without uveitis and 60 eyes of 31 healthy children were included. Corneal/lenticular optical density, corneal volume, central corneal thickness, keratometry were analyzed by Pentacam HR. Corneal endothelial cell density, hexagonal cell ratio and coefficient of variation were measured by specular microscope. The mean age was 12.0 ± 3.1 years, 11.9 ± 4.0 years and 11.3 ± 3.4 years whereas the female/ratio was 15/14, 15/13 and 14/17 in uveitis, systemic inflammation and control groups respectively. Uveitis type was anterior uveitis in 16 (29.1%) eyes, intermediate uveitis in 32 (58.2%) eyes and panuveitis in 7 (12.7%) eyes. Twenty-two (40%) eyes had active uveitis whereas 33 (60%) eyes had inactive uveitis. Corneal optical density was greater in uveitis group compared with other groups (p = 0.001, Kruskal-Wallis test). Lenticular density and corneal parameters other than optical density were not different between the groups (p > 0.05). Corneal optical density was higher in active uveitis than inactive uveitis (22/33 eyes, p = 0.017). Children with uveitis had decreased corneal clarity compared with systemic inflammation group and healthy controls, while lenticular clarity was similar between the groups. Corneal endothelial parameters did not change significantly based on ocular/systemic inflammation. Scheimpflug imaging provides objective corneal and lenticular optical density measurements. [ABSTRACT FROM AUTHOR]

Objective Acromegaly has various impacts on many organs. The ophthalmologic effects of acromegaly have not yet been investigated in detail. The aim of the current study was to evaluate qualitative and quantitative changes in corneal endothelial cells and central corneal thickness (CCT) of the patients with acromegaly. Design In this prospective, cross-sectional study, 128 eyes of 64 patients with acromegaly (female/male = 40/24) and 208 eyes of 104 age and gender-matched healthy volunteers (female/male = 69/35) were included. Endothelial cell density (ECD), cellular area (CA), coefficient of variation (CV) in cell size, percentage of hexagonal cells, and CCT were measured in patients with acromegaly and in healthy volunteers using the noncontact specular microscopy (SP-3000P: Topcon Corporation, Tokyo, Japan). Results ECD and CA were lower in cases with acromegaly than in controls (ECD in acromegaly: 2615.65 cell/mm 2 and in controls: 2700.35 cell/mm 2 ; p = 0.002. CA in acromegaly: 382.30 μm 2 and in controls: 400.30 μm 2 ; p = 0.02). In the entire group with acromegaly, the time elapsed since diagnosis was positively correlated with CA and was negatively correlated with ECD (r = + 0.39, p = 0.001 and r = − 0.42, p = 0.001). Conclusions The endothelial layer of the cornea may be under risk of impairment with prolonged disease duration in acromegaly. Consistency of the corneal endothelium should be also sought during long-term follow-up of the cases with acromegaly. [ABSTRACT FROM AUTHOR]

Abstract: Due to the high demand for donor corneas and their low supply, autologous corneal endothelial cell (CEC) culture and transplantation for treatment of corneal endothelial dysfunction would be highly desirable. Many studies have shown the possibility of culturing CECs in vitro, but lack potential robust substrates for transplantation into the cornea. In this study, we investigate the properties of novel ultrathin chitosan–poly(ethylene glycol) (PEG) hydrogel films (CPHFs) for corneal tissue engineering applications. Cross-linking of chitosan films with diepoxy-PEG and cystamine was employed to prepare ∼50μm (hydrated) hydrogel films. Through variation of the PEG content (1.5–5.9wt.%) it was possible to tailor the CPHFs to have tensile strains and ultimate stresses identical to or greater than those of human corneal tissue while retaining similar tensile moduli. Light transmission measurements in the visible spectrum (400–700nm) revealed that the films were >95% optically transparent, above that of the human cornea (maximum ∼90%), whilst in vitro degradation studies with lysozyme revealed that the CPHFs maintained the biodegradable characteristics of chitosan. Cell culture studies demonstrated the ability of the CPHFs to support the attachment and proliferation of sheep CECs. Ex vivo surgical trials on ovine eyes demonstrated that the CPHFs displayed excellent characteristics for physical manipulation and implantation purposes. The ultrathin CPHFs display desirable mechanical, optical and degradation properties whilst allowing attachment and proliferation of ovine CECs, and as such are attractive candidates for the regeneration and transplantation of CECs, as well as other corneal tissue engineering applications. [Copyright &y& Elsevier]

Abstract: Corneal endothelial diseases lead to severe vision impairment, motivating the transplantation of donor corneae or corneal endothelial lamellae, which is, however, impeded by endothelial cell loss during processing. Therefore, one prioritized aim in corneal tissue engineering is the generation of transplantable human corneal endothelial cell (HCEC) layers. Thermo-responsive cell culture carriers are widely used for non-enzymatic harvest of cell sheets. The current study presents a novel thermo-responsive carrier based on simultaneous electron beam immobilization and cross-linking of poly(vinyl methyl ether) (PVME) on polymeric surfaces, which allows one to adjust layer thickness, stiffness, switching amplitude and functionalization with bioactive molecules to meet cell type specific requirements. The efficacy of this approach for HCEC, which require elaborate cell culture conditions and are strongly adherent to the substratum, is demonstrated. The developed method may pave the way to tissue engineering of corneal endothelium and significantly improve therapeutic options. [Copyright &y& Elsevier]

Abstract: This short review summarizes the localization and effects of the plant lectin soybean agglutinin (SBA) on the injured and non-injured organ-cultured rat corneal endothelium. Although the tissue exists as a non-cycling monolayer on the posterior corneal surface a circular freeze injury promotes wound repair as cells initiate DNA synthesis, mitosis and migration. As a result, by 24 h post-injury, endothelial cells express a surface protein that binds SBA in a diffuse punctate pattern, which by 48 h after injury, becomes confined to the cell periphery. As healing proceeds, SBA binding dramatically declines, such that, only scattered binding is observed by 72 h after wounding. In non-injured organ-cultured endothelia, weak SBA binding appears 24 h after explanation but becomes prominently detected around the cell periphery by 48 h. Incubating injured or non-injured endothelia in SBA leads to alterations in their cellular appearance due to the fact that lectin exposure results in the disruption of the actin cytoskeleton. Although this does not affect migration, treatment with either SBA or N-acetylgalactosamine (the SBA binding sugar) does interfere with the reestablishment of cell–cell contact. It is postulated that the surface protein that binds SBA is expressed during conditions that are stressful to the tissue. During organ-culture the protein''s appearance suggests a cellular response to explantation in order to enhance or maintain monolayer integrity. In wound repair its appearance may serve to establish preliminary cell–cell contact during the restoration of the endothelial monolayer. [Copyright &y& Elsevier]

Copyright of Canadian Journal of Ophthalmology is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objective: To investigate the biological function of platelet-derived growth factor B (PDGF-B) on the survival and proliferation of cat corneal endothelial cells so as to provide bases for further studies of its role in wound repair and its clinical application. Methods: Total RNA was extracted from the placenta tissues of healthy pregnant women undergoing hysterotokotomy and PDGF cDNA was obtained with reverse transcription-polymerase chain r e action (RT-PCR). The prokaryotic expression vector pET-PDGF-B was constructed and expressed the recombinant PDGF-B in Escherichia coli (E.coli) BL21 (DE3). After purification and refolding on Ni2+ – chelation affinity chromatography (NTA) column, it was used to culture cat corneal endothelial cells. Cell proliferation was tested by modified tertrazolium salt (MTT) and flow cy tometer. And the morphologic change and the ultrastructure were observed under an inverted phase contrast microscope, a scanning electron microscope and a transmission electon microscope, respectively. Results: PDGF-B chain peptide (PDGF-BB) gene was successfully inserted into the prokaryotic expression vector, pET-28a (+). The purified recombined protein pET-PDGF-B showed a single band on sodium dodecyl sulfate polyacry-lamide gel electropheresis (SDS-PAGE) with the molecular weight of about 27 u, which was in agreement with the deduced value. MTT and flow cytometry showed that PDGF-BB promoted the survival and proliferation of cat corneal en-dothelial cells. Conclusions: The construction of recombinant prokary-otic expression vector pET-PDGF-B and the preparation of PDGF-BB protein provide a foundation for further study of the function of PDGF-BB and producing biological PDGF-BB protein. The expressed PDGF-BB promotes the proliferation of cultured cat corneal endothelial cells. [Copyright &y& Elsevier]

Abstract: Background: Ocular disorders associated with the human immunodeficiency virus are numerous as are ocular side effects from medications used to treat all of the manifestations of the virus. This report presents a unique case of bilateral, peripheral, and corneal endothelial deposits that may be a result of either the human immunodeficiency virus or the medication rifabutin. Rifabutin was the only medication prescribed that is known to cause endothelial deposits. Rifabutin is part of a multidrug therapy to prevent or treat Mycobacterium avium complex, a common pulmonary disease of immunocompromised individuals. Case report: A 69-year-old man with a 20-year history of being human immunodeficiency virus–positive presented with bilateral, asymptomatic, peripheral, and corneal endothelial deposits of unknown etiology. Literature research suggested that the deposits did not appear like cytomegalovirus retinitis–related deposits but rather a variant of rifabutin-associated deposits. Conclusions: These rifabutin-associated deposits differed from known rifabutin-associated deposits previously reported in the literature. These deposits have increased in pigmentation and density 5 years after the patient discontinued the drug. This case may represent another variation of rifabutin-associated endothelial deposits. Knowledge of human immunodeficiency virus and all the associated ocular findings (owing to both the condition and its treatment) is important, because the length of time patients are living with human immunodeficiency virus is increasing. [Copyright &y& Elsevier]

Abstract: The inner layer of the human cornea, called the corneal endothelium, plays an important role in the maintenance of corneal transparency. Specular microscopy is the most widely used technique to study the corneal endothelium in vivo. Improvements in technology have allowed us to obtain good quality specular images, but the detection and quantification of small size–shape cell changes is not obvious, specially when the physician wants to evaluate endothelial cell changes after some surgical procedures. This paper proposes a methodology to analyze specular microscopy images. Every corneal endothelium is described by means of different cumulative distribution functions or some moments (mean, standard deviation, kurtosis, and skewness) of these distribution functions. These distributions are defined from different granulometries based on successive structural openings of the corneal endothelium. Changes in cell morphology are pointed out by comparing the cumulative distribution function (or the corresponding moments) of a given patient with the corresponding cumulative distribution functions (or their moments) of a group of age-matched controls. Different comparison procedures are given, providing us with different numerical evaluations of the corneal endothelium status. These new indices are compared with the classic descriptors used in commercial packages (density, hexagonality, and coefficient of variation of cell areas). Detailed analysis of different images of corneal endothelia are given using the classic and new indices jointly. [Copyright &y& Elsevier]

• Regular eye examination is crucial in patients with psoriasis, for early detection and management of ocular involvement. • Corneal changes especially endothelial alterations can be important in patients with psoriasis. • Psoriasis could lead to dry eye disease. To evaluate corneal endothelial properties and corneal densitometry values in patients with psoriasis and to compare the results with those of healthy controls. This prospective, comparative, and cross-sectional study included 106 eyes of 53 patients who were diagnosed with psoriasis and 106 eyes of 53 age-gender matched healthy controls. All patients were evaluated in terms of ocular surface tests such as Schirmer-1 and tear break-up time (TBUT). Corneal endothelial measurements were performed using noncontact specular microscopy. Corneal tomographic and densitometric measurements were obtained using the Scheimpflug imaging system. Measurements were also evaluated according to the psoriasis area and severity index (PASI) score. The mean TBUT and Schirmer 1 test values were significantly lower in the psoriasis group than in the healthy controls (p = 0.02, p < 0.001, respectively). While the mean endothelial cell density was significantly lower in patients with psoriasis than the healthy controls (2389.9±314.9 cells/mm2 vs. 2512.4±289.7 cells/mm2, p = 0.02), the mean average endothelial cell area, standard deviation of cell area, coefficient of variation of cell area were significantly higher in patients with psoriasis (426.6±62.7 µm2 vs. 403.2±46.1 µm2, p = 0.01; 206.4±52.3 µm2 vs. 183.2±43.8 µm2, p = 0.006; and 48.1±6.3% vs. 45.7±6.7%, p = 0.04, respectively). Most of the densitometry measurements in concentric zones were higher in patients with psoriasis than in healthy controls, but none of the differences reached statistical significance. A regular eye examination is crucial in patients with psoriasis because corneal structural and functional changes, particularly endothelial alterations, are of utmost importance in planning intraocular surgeries in patients with psoriasis. [ABSTRACT FROM AUTHOR]

Abstract: Cytomegalovirus (CMV)-related corneal endotheliitis is an inflammation of the corneal endothelium caused by CMV. It typically presents as coin-shaped keratic precipitates (KPs), with or without corneal edema, in otherwise healthy individuals. It may be associated with anterior uveitis and raised intraocular pressure (IOP). Patients with CMV-related corneal endotheliitis respond to systemic and topical ganciclovir with the use of topical steroid. Making an accurate early diagnosis is crucial in preventing loss of corneal endothelial cells and unnecessary treatment resulting from misdiagnosis in these patients. [Copyright &y& Elsevier]