Secondary Data Analysis of Inflammation-Related mRNAs in Conjunctival Impression Cytology Samples of Aniridia Patients.

PURPOSE: Aniridia is a rare corneal disease that is often associated with aniridia-associated keratopathy (AAK). In AAK, the conjunctival tissue crosses the limbal border, forming a corneal pannus that extends into the corneal center. With increasing AAK severity, corneal pannus formation, vascularization, and ocular surface inflammation increase. The purpose of this study was to investigate inflammation-related mRNA expression in conjunctival epithelial cells in AAK and its relationship with AAK severity. METHODS: Using impression cytology, bulbar conjunctival cells were sampled from 20 subjects with congenital aniridia and 20 age-matched and sex-matched healthy control subjects. RNA was extracted, and mRNA analyses were performed using microarray, which was evaluated for inflammatory markers. RESULTS: In the analyzed aniridia subjects, 70 deregulated mRNAs encoding proinflammatory or antiinflammatory cytokines or factors associated with chronic inflammation, including increased IL-1, IL-8, and MIP3A/CCL20 mRNA. The most downregulated mRNA was TIMP3, and the most upregulated mRNA was Protein c-Fos.Of the 70 mRNAs, 14 inflammation-related genes were altered only in the mild AAK forms, whereas only 2 mRNAs were altered only in the severe AAK forms (TLR4 and PPARG). CONCLUSIONS: The expression of numerous proinflammatory and antiinflammatory cytokines is deregulated at the ocular surface of aniridia subjects with mild AAK. Thus, early antiinflammatory treatment may prevent or slow down corneal scarring and pannus formation in aniridia subjects.

Long-Term Benefits of Tear Exchangeable Limbal-Rigid Contact Lens Wear Therapy in Stevens-Johnson Syndrome Cases.

OBJECTIVES: To evaluate the long-term benefits of tear-exchangeable, limbal-rigid contact lens (CL) wear therapy in patients with Stevens-Johnson syndrome (SJS)-associated ocular sequelae. METHODS: This retrospective study evaluated 50 eyes of 41 SJS patients (15 men and 26 women) who underwent limbal-rigid CL wear therapy for more than 2 years post fitting. Ocular sequelae (i.e., conjunctival hyperemia, corneal neovascularization, and upper tarsus scarring) before fitting and at 3 months, 6 months, 12 months, and annually after initiating CL wear therapy were evaluated and then graded on a severity score (range: 0-3, maximum score: 3). Moreover, visual acuity (VA) at immediately post initiating CL wear therapy was evaluated. RESULTS: The mean follow-up period was 4.3±1.1 years. Compared with before fitting, the mean conjunctival hyperemia score improved from 1.14 to 0.86 at 3 months of CL wear therapy ( P <0.01) and was maintained thereafter; the mean corneal neovascularization score improved from 2.10 to 1.98 at 3 months of CL wear therapy, with no deterioration of the score observed in all cases at the final follow-up examination, and mean VA (log of minimum angle of resolution) improved from 1.60 to 1.04 at immediately post initiating CL wear therapy ( P <0.01). CONCLUSIONS: Limbal-rigid CL wear therapy can provide long-term ocular surface stabilization and improved VA in SJS patients.

[Clinical analysis of penetrating keratoplasty for infants with congenital corneal opacity].

Objective: To investigate the corneal graft survival and related risk factors of primary penetrating keratoplasty in congenital corneal opacity infants. Methods: It was a retrospective cohort study. Data were collected from forty-two infants (51 eyes) who were aged ≤12 months and diagnosed with congenital corneal opacity in Beijing Tongren Hospital and Beijing Anzhen Hospital from January 1, 2017 to January 31, 2018. The mean age at surgery was (5.7±2.2) months (3-12 months). The mean follow-up duration was (28.6±2.6) months (24-33 months). All the patients underwent penetrating keratoplasty. The status of the corneal grafts and complications were observed and recorded during the regular follow-up. The survival probabilities were estimated by using the Kaplan-Meier and Log-rank test. The graft survival between different influence factors was analyzed by using the χ2 test. Results: The Kaplan-Meier survival rates for penetrating keratoplasty were 84.3% (43/51) at 6 months, 78.4% (40/51) at 12 months and 60.8% (31/51) at the last follow-up. The presence of corneal neovascularization was significantly correlated with graft failure (χ²=5.264, P=0.022). The graft survival differed between eyes receiving combined surgery and mere penetrating keratoplasty and in eyes with varied surgical indications (P=0.039, <0.01). Increased intraocular pressure (7 eyes, 13.7%) and persistent epithelial defects (7 eyes, 13.7%) were the most common postoperative complications, followed by complicated cataract (4 eyes, 7.8%) and posterior capsule opacification (2 eyes, 3.9%). Conclusions: The graft survival rate was satisfactory following pediatric keratoplasty although it had a tendency to decrease with the follow-up time. Corneal neovascularization was a major risk factor of graft failure. Surgical indications and procedures also had a certain effect on the graft survival.

AIP1 suppresses neovascularization by inhibiting the NOX4-induced NLRP3/NLRP6 imbalance in a murine corneal alkali burn model.

BACKGROUND: Apoptosis signal-regulating kinase 1-interacting protein 1 (AIP1) participates in inflammatory neovascularization induction. NADPH oxidase 4 (NOX4) produces reactive oxygen species (ROS), leading to an imbalance in nucleotide-binding oligomerization domain-like receptor family pyrin domain containing 3 (NLRP3) and NLR family pyrin domain containing 6 (NLRP6) expression. The mechanisms of AIP1, NOX4, ROS and inflammasomes in corneal neovascularization were studied herein. METHODS: C57BL/6 and AIP1-knockout mice were used in this study. The alkali burn procedure was performed on the right eye. Adenovirus encoding AIP1 plus green fluorescence protein (GFP) (Ad-AIP1-GFP) or GFP alone was injected into the right anterior chamber, GLX351322 was applied as a NOX4 inhibitor, and then corneal neovascularization was scored. The expression of related genes was measured by quantitative real-time polymerase chain reaction, western blotting and immunofluorescence staining. 2',7'-Dichlorofluorescin diacetate staining was used to determine the ROS levels. RESULTS: The expression of AIP1 was decreased, while that of cleaved interleukin-1ß (clv-IL-1ß) and vascular endothelial growth factor A (VEGFa) was increased after alkali burn injury. NOX4 expression was increased, the imbalance in NLRP3/NLRP6 was exacerbated, and corneal neovascularization was increased significantly in AIP1-knockout mice compared with those in C57BL/6 mice after alkali burns. These effects were reversed by AIP1 overexpression. NLRP3/NLRP6 expression was imbalanced after alkali burns. GLX351322 reversed the imbalance in NLRP3/NLRP6 by reducing the ROS levels. This treatment also reduced the expression of clv-IL-1ß and VEGFa, suppressing neovascularization. CONCLUSIONS: AIP1 and NOX4 can regulate corneal inflammation and neovascularization after alkali burn injury. Based on the pathogenesis of corneal neovascularization, these findings are expected to provide new therapeutic strategies for patients. Corneal alkali burn injury is a common type of ocular injury that is difficult to treat in the clinic. The cornea is a clear and avascular tissue. Corneal neovascularization after alkali burn injury is a serious complication; it not only seriously affects the patient's vision but also is the main reason for failed corneal transplantation. Corneal neovascularization affects approximately 1.4 million patients a year. We show for the first time that AIP1 and NOX4 can regulate corneal inflammation and neovascularization after alkali burns. The expression of AIP1 was decreased, while that of clv-IL-1ß and VEGFa was increased after alkali burns. We tried to elucidate the specific molecular mechanisms by which AIP1 regulates corneal neovascularization. NOX4 activation was due to decreased AIP1 expression in murine corneas with alkali burns. NOX4 expression was increased, the imbalance in NLRP3/NLRP6 was exacerbated, and corneal neovascularization was increased significantly in AIP1-knockout mice compared with those in C57BL/6 mice after alkali burns. These effects were reversed by AIP1 overexpression. Additionally, NLRP3/NLRP6 expression was unbalanced, with NLRP3 activation and NLRP6 suppression in the corneal alkali burn murine model. Eye drops containing GLX351322, a NOX4 inhibitor, reversed the imbalance in NLRP3/NLRP6 by reducing ROS expression. This treatment also reduced the expression of clv-IL-1ß and VEGFa, reducing neovascularization. Therefore, we provide new gene therapeutic strategies for patients. With the development of neovascularization therapy, we believe that in addition to corneal transplantation, new drug or gene therapies can achieve better results. Video Abstract.

Descemet Membrane Endothelial Keratoplasty in Vascularized Eyes: Outcome and Effect on Corneal Neovascularization.

PURPOSE: To report the outcomes after Descemet membrane endothelial keratoplasty (DMEK) in vascularized eyes. METHODS: Consecutive cases of DMEK in vascularized eyes (involving ≥2 vascularized quadrants) were selected from a prospective database. Best corrected visual acuity, endothelial cell density (ECD), central corneal thickness, corneal transplant rejection episode, graft survival, and area of neovascularization (quantified using image analysis software) were evaluated. RESULTS: In this study, 24 eyes of 24 patients were selected [mean age, 65.0 years; mean follow-up duration, 14.8 months (6-36 months)], which consists of 14 vascularized eyes after failed penetrating keratoplasty and 10 vascularized eyes with bullous keratopathy. Best corrected visual acuity improved from 1.60 ± 1.02 LogMAR preoperatively to 0.47 ± 0.37 LogMAR 12 months postoperatively (P < 0.001). Central corneal thickness decreased from 824 ± 193 µm preoperatively to 544 ± 48 µm 12 months postoperatively (P = 0.001). The donor ECD decreased from 2272 ± 723 cells/mm2 preoperatively to 1570 ± 279 cells/mm2 12 months postoperatively. The total loss of ECD at the last visit was 40.7% ± 13.0%. Eight of 24 eyes (33.3%) required rebubbling, which resulted in final attachment. The corneal neovascularization area significantly regressed from 4.68% ± 3.26% preoperatively to 2.28% ± 1.58% (n = 18, P = 0.021). Corneal transplant rejection episodes occurred in 1 eye of 24 patients (4.2%). There was no primary graft failure. CONCLUSIONS: DMEK is a feasible option to treat endothelial dysfunction in vascularized eyes.

A de novo mutation in PITX2 underlies a unique form of Axenfeld-Rieger syndrome with corneal neovascularization and extensive proliferative vitreoretinopathy.

BACKGROUND: Axenfeld-Rieger syndrome is characterized by a spectrum of anterior segment dysgenesis involving neural-crest-derived tissues, most commonly secondary to mutations in the transcription factor genes PITX2 and FOXC1. MATERIALS AND METHODS: Single retrospective case report. RESULTS: A full-term infant presented at 5 weeks of age with bilateral Peters anomaly and Axenfeld-Rieger syndrome, with development of atypical features of progressive corneal neovascularization and proliferative vitreoretinopathy. Despite surgical interventions, the patient progressed to bilateral phthisis bulbi by 22 months of age. Genetic testing revealed a novel de novo p.Leu212Valfs*39 mutation in PITX2, leading to loss of a C-terminal OAR domain that functions in transcriptional regulation. CONCLUSIONS: It is important to consider mutations in PITX2 in atypical cases of anterior segment dysgenesis that also present with abnormalities in the angiogenesis of the anterior and posterior segments.

Streptozotocin­induced diabetic mice exhibit reduced experimental choroidal neovascularization but not corneal neovascularization.

The present study aimed to investigate the effects of diabetes mellitus (DM) on the generation of experimental corneal neovascularization (CrNV) and choroidal neovascularization (ChNV). Diabetes was induced in mice by intraperitoneal injection of streptozotocin (STZ). Experimental CrNV and ChNV were induced by alkali injury and laser photocoagulation, respectively. CrNV and ChNV were compared between the STZ­induced diabetic mice and control mice two weeks after injury. Relative expression of angiogenic factors was quantified by reverse transcription­quantitative polymerase chain reaction, and progenitor cell or macrophage accumulation in the early phase following injury was examined by flow cytometric analysis. Compared with the alkali­injured normal mice, the alkali­injured diabetic mice (STZ­induced) exhibited no significant difference in CrNV occurrence, whereas the laser­injured diabetic mice exhibited significantly reduced levels of ChNV compared with those of the laser­injured control animals. The laser­induced intrachoroidal mRNA expression levels of angiogenic factors, including vascular endothelial growth factor, hypoxia­induced factor­1α, chemokine (C­C motif) ligand 3, and stromal cell­derived factor­1α, were reduced in the laser­injured diabetic mice when compared with laser­injured control mice. Furthermore, the laser­induced intrachoroidal infiltration of c­Kit+ progenitor cells was impaired in the laser­injured diabetic mice compared with the laser­injured control mice. Overall, diabetes did not exert a significant effect on the generation of experimental CrNV. However, diabetes reduced laser­induced ChNV through downregulation of intrachoroidal progenitor cell infiltration and angiogenic factor expression.

Visualization of corneal vascularization in peripheral hypertrophic subepithelial corneal opacification with OCT angiography.

PURPOSE: The major goal of this study was to test the hypothesis that in patients with peripheral hypertrophic subepithelial corneal opacification (PHSCO), visualization of corneal vessels is better with optical coherence tomography angiography (OCTA) than with conventional slit lamp microphotography. METHODS: Patients with PHSCO were included in this prospective study. The corneal findings were photographed using a slit lamp camera (Haag Streit BM 900® ) and visualized with anterior-segment OCT (Optovue XR Avanti, Fremont, California, USA). Additionally, OCTA with the Angiovue Imaging™ System was performed in the area of PHSCO. RESULTS: Thirty-four eyes of 19 patients (26% male and 74% female) with PHSCO were included in this study. In 21 eyes, vascularization in the area of PHSCO was visualized with the Angiovue-OCT, whereas only 10 eyes presented vessels in slit lamp photographs. CONCLUSION: Optical coherence tomography angiography allows better visualization of corneal neovascularization than slit lamp photography in patients with PHSCO. Corneal opacifications were found predominantly nasally, which was reflected by a local enlargement of corneal thickness.

In Vivo Confocal Microscopic Study of Hard Contact Lens-Induced Lipid Keratopathy Secondary to Corneal Neovascularization in a Rabbit Hypercholesterolemic Model.

OBJECTIVES: In vivo confocal microscopy was used to observe the morphological presentations and anatomical correlations between corneal neovascularization (NV) and intracorneal lipid deposition in a rabbit model of contact lens (CL)-induced lipid keratopathy secondary to corneal NV. METHODS: Rabbits were divided into 3 groups: (1) 8-week normal diet, (2) 8-week high-cholesterol diet, and (3) 4-week normal diet followed by 4-week high-cholesterol diet. Corneal NV was induced by closed-eye CL. The formation and maturation of corneal NV were shown by immunohistochemical staining against CD31 and high-molecular-weight melanoma-associated antigen. In vivo confocal microscopy identified corneal NV and lipid deposition. Acquired images for each eye were arranged and mapped into subconfluent montages. RESULTS: In group 1, corneal NV sprouting formed from the peripheral to the central cornea by the end of week 4. Pericytes around vessels were shown after 2 weeks of CL wear. In group 2, lipid deposition started from the peripheral cornea and progressively covered the whole cornea. In group 3, lipid deposition was found first in the central cornea after 2 weeks of high-cholesterol diet and progressed to cover the peripheral cornea. In vivo confocal microscopy demonstrated four different patterns of intracorneal lipid deposition: spindle shapes arranged randomly or in parallel, amorphous shapes, multiangular shapes, and mixed types. Intracorneal lipid deposition was distributed from basal corneal epithelium to deep stroma. CONCLUSIONS: Intracorneal lipids tend to accumulate around newly formed corneal NV but can extend to the area covered with mature NV. In vivo confocal microscopy can demonstrate various shapes and depths of intracorneal lipid deposition.

Management of high-risk corneal transplantation.

The cornea is the most commonly transplanted tissue in medicine. The main cause of corneal graft failure is allograft rejection. The incidence of graft rejection depends on the presence of high-risk characteristics, most notably corneal neovascularization. Although corneal grafting has high success rates in the absence of these risk factors, high-risk keratoplasty is associated with low success rates because of a high incidence of immune-mediated graft rejection. To improve the survival of high-risk corneal transplantation, various preoperative, intraoperative, and postoperative measures can be considered; however, the key step in the management of these grafts is the long-term use of local and/or systemic immunosuppressive agents. Although a number of immunosuppressive agents have been used for this purpose, the results vary significantly across different studies. This is partly due to the lack of an optimized method for their use, as well as the lack of a precise stratification of the degree of risk in each individual patient. New targeted biologic treatments, as well as tolerance-inducing methods, show promising horizons in the management of high-risk corneal transplantation in near future.

Involvement of NADPH oxidases in alkali burn-induced corneal injury.

Chemical burns are a major cause of corneal injury. Oxidative stress, inflammatory responses and neovascularization after the chemical burn aggravate corneal damage, and lead to loss of vision. Although NADPH oxidases (Noxs) play a crucial role in the production of reactive oxygen species (ROS), the role of Noxs in chemical burn-induced corneal injury remains to be elucidated. In the present study, the transcription and expression of Noxs in corneas were examined by RT-qPCR, western blot analysis and immunofluorescence staining. It was found that alkali burns markedly upregulated the transcription and expression of Nox2 and Nox4 in human or mouse corneas. The inhibition of Noxs by diphenyleneiodonium (DPI) or apocynin (Apo) effectively attenuated alkali burn-induced ROS production and decreased 3-nitrotyrosine (3-NT) protein levels in the corneas. In addition, Noxs/CD11b double­immunofluorescence staining indicated that Nox2 and Nox4 were partially co-localized with CD11b. DPI or Apo prevented the infiltration of CD11b-positive inflammatory cells, and inhibited the transcription of inflammatory cytokines following alkali burn-induced corneal injury. In our mouse model of alkali burn-induced corneal injury, corneal neovascularization (CNV) occurred on day 3, and it affected 50% of the whole area of the cornea on day 7, and on day 14, CNV coverage of the cornea reached maximum levels. DPI or Apo effectively attenuated alkali burn­induced CNV and decreased the mRNA levels of angiogenic factors, including vascular endothelial growth factor (VEGF), VEGF receptors and matrix metalloproteinases (MMPs). Taken together, our data indicate that Noxs play a role in alkali burn-induced corneal injury by regulating oxidative stress, inflammatory responses and CNV, and we thus suggest that Noxs are a potential therapeutic target in the future treatment of chemical-induced corneal injury.

An unusual presentation of generalized essential telangiectasia.

Generalized essential telangiectasia (GET) is a rare skin condition of unknown aetiology. We report a case of a 39-year-old man who presented to the ophthalmology department with reduced vision, and was diagnosed with generalized essential telangiectasia by indocyanine green and fluorescein angiography of his eyes. The patient was noted to have corneal neovascularization (which was responsible for his reduced visual acuity) and conjunctival telangiectases seen by angiography. Further examination by the dermatology department identified widespread telangiectases on the patient's legs and trunk. Systemic causes and alternative diagnoses were excluded by further investigations, and the patient was eventually diagnosed with GET. Following discharge from the dermatology department, the patient presented with chest pain and required emergency surgery for a type A thoracic aortic dissection. Previous research has not identified an association between GET, corneal neovascularization and thoracic aortic aneurysm formation.

Novel lamellar, flap-based tattooing techniques for corneal opacities in scarred and vascularized blind eyes.

PURPOSE: The aim of this study was to describe novel, flap-based tattooing techniques for the treatment of disfiguring corneal scars in blind eyes. METHODS: Several new modifications of intrastromal corneal tattooing techniques were performed in 6 patients. In corneas with a low risk of perforation, a large limbus-to-limbus lamellar flap was prepared, and the tattooing dyes were spread over the entire stromal bed. After additional puncturing of the dyes into the stroma, the flap was closed and sutured ("large flap technique"). In fragile corneas where convenient preparation of a large flap was not possible, a central small flap was prepared, and the "pupil" was tattooed in analogy ("small flap technique"). Afterward, the corneal periphery corresponding to the "iris" was tattooed, either by puncturing or injecting the dye into peripheral intrastromal tunnels ("tunnel technique"). RESULTS: Two eyes were tattooed using a large flap, and 4 eyes were tattooed using a small flap. Here, the corneal periphery of 3 eyes was tattooed by puncturing, whereas 1 eye was tattooed using the tunnel technique. All tattooing procedures were performed without complications and with good cosmetic results. CONCLUSIONS: These novel, flap-based tattooing techniques are alternatives to previously reported procedures and can be adapted to the individual corneal constitution. Further, the tunnel technique is an easy-to-perform method that provides good tattooing results.

Angiofluorographic aspects in age-related macular degeneration.

Although AMD (age-related macular degeneration) has been described for over 100 years, there is neither a standard agreement on the definition of specific lesions nor a generally accepted classification system. For example, the age limits for AMD varied widely in different clinical studies; the methods used for examination also vary (visual acuity, perimetry, contrast sensitivity, slit lamp examination of the fundus, retinal photography, fluorescein angiography, indocyanine green angiography). We described the multitude of angiofluorographic aspects in patients with AMD and conceived a classification to be easily used in clinical practice. Although a detailed ophthalmoscopy can often identify the characteristic lesions of AMD, a complete picture is obtained by fluorescein angiography. The angiographic classification of AMD is structured similarly to the clinical one. It has two main patterns, non-exudative and exudative lesions, but it provides more information about the nature of the lesions. In the last three decades, an impressive amount of information regarding the prevalence, progression and risk factors for AMD has been published. The source of this information is mainly represented by the large population studies that are often multicenter studies. Recognizing the clinical signs of AMD and classifying them into different stages is important for the prognosis and the therapeutical decision, but also for conceiving study protocols.

Pathogenesis of herpes stromal keratitis--a focus on corneal neovascularization.

The cornea is a complex sensory organ that must maintain its transparency for optimal vision. Infections such as with herpes simplex virus can result in blinding immunoinflammatory reactions referred to as herpes stromal keratitis (HSK). In this review we discuss the pathogenesis of HSK referring to work mainly done using animal model systems. We briefly discuss the role of multiple cell types and soluble mediators but focus on the critical role of corneal vascularization (CV) in contributing to corneal damage. We describe how VEGF and other angiogenic molecules are induced following infection and discuss the many ways by which CV can be controlled. Speculations are made regarding future approaches that could improve the management of HSK.

Role of miR-132 in angiogenesis after ocular infection with herpes simplex virus.

MicroRNAs (miRNAs) are small regulatory molecules that control diverse biological processes that include angiogenesis. Herpes simplex virus (HSV) causes a chronic immuno-inflammatory response in the eye that may result in corneal neovascularization during blinding immunopathological lesion stromal keratitis (SK). miR-132 is a highly conserved miRNA that is induced in endothelial cells in response to growth factors, such as vascular endothelial growth factor (VEGF). In this study, we show that miR-132 expression was up-regulated (10- to 20-fold) after ocular infection with HSV, an event that involved the production of both VEGF-A and IL-17. Consequently, blockade of VEGF-A activity using soluble VEGF receptor 1 resulted in significantly lower levels of corneal miR-132 after HSV infection. In addition, low levels of corneal miR-132 were detected in IL-17 receptor knockout mice after HSV infection. In vivo silencing of miR-132 by the provision of anti-miR-132 (antagomir-132) nanoparticles to HSV-infected mice led to reduced corneal neovascularization and diminished SK lesions. The anti-angiogenic effect of antagomir-132 was reflected by a reduction in angiogenic Ras activity in corneal CD31-enriched cells (presumably blood vessel endothelial cells) during SK. To our knowledge, this is one of the first reports of miRNA involvement in an infectious ocular disease. Manipulating miRNA expression holds promise as a therapeutic approach to control an ocular lesion that is an important cause of human blindness.

Inhibition of VEGF expression and corneal neovascularization by shRNA targeting HIF-1α in a mouse model of closed eye contact lens wear.

PURPOSE: Inappropriate contact lens (CL) use and care often lead to corneal neovascularization (corneal NV). We used mouse eyes which wore CL as the animal model to assess the reason for corneal NV with CL wear. The similar and overlapping activity of vascular endothelial growth factor (VEGF) and the potent angiogenic hypoxia-inducible factor 1α (HIF-1α) called for a study of the temporal relationship in the expression of these two autocoids. We determined the time dependent expression of HIF-1α and correlated it to that of VEGF expression in the mouse model of closed eye with CL wear. METHODS: Mouse eyes were fitted with CL followed by a silk suture tarsorrhaphy. The anterior surface was analyzed at 4, 7, and 10 days after tarsorrhaphy by slit lamp and corneal NV. HIF-1α and VEGF levels were measured by reverse transcription PCR, western blotting and immunofluorescence with specific primers and antibodies. We used shRNA targeting HIF-1α to substantiate the link between HIF-1α, VEGF expression, and angiogenesis in the CL wear model. RESULTS: Corneal NV scores increased in a time dependent manner in the model of closed eye CL induced hypoxic injury. Corneal epithelial HIF-1α and VEGF expression increased in a time dependent manner. The prolonged hypoxic state brought by closed eye CL wear induced a time dependent neovascular response which was significantly attenuated by HIF-1α specific shRNA but not by nonspecific shRNA. Both HIF-1α and VEGF levels were reduced significantly in corneal homogenates from eyes treated with the HIF-1α specific shRNA. CONCLUSIONS: The present study documented the increased expression of HIF-1α in the corneal epithelium during CL wear. It also demonstrated the presence of VEGF in the corneal epithelium and its increased expression in this model. Altogether, the results of this study raised the possibility of interaction between HIF-1α and VEGF, in mediating the neovascularization response induced by the prolonged hypoxic state brought about by closed eye CL wear. The results strongly implicated corneal HIF-1α as a component of the inflammatory and neovascular cascade initiated by hypoxic and further suggested that HIF-1α was a proximal regulator of VEGF expression in this model.

KLEIP deficiency in mice causes progressive corneal neovascular dystrophy.

PURPOSE: The BTB-kelch protein KLEIP/KLHL20 is an actin binding protein that regulates cell-cell contact formation and cell migration. The aim of our study was to characterize KLEIP's function in ocular health and disease in mice. METHODS: KLEIP(-/-) mice were generated, and corneas were examined histologically and stained for keratin-1, loricrin, keratin-12, keratin-14, CD31, LYVE-1, F4/80, E-cadherin, and Ki67. Corneal abrasions were performed after eyelid opening. RESULTS: Corneas of KLEIP(+/+) and KLEIP(-/-) mice were indistinguishable at birth. After eyelid opening corneal epithelial hyperplasia started to manifest in KLEIP(-/-) mice, showing a progressive epithelial metaplasia leading to total corneal opacity. In KLEIP(-/-) mice the initial stratified squamous corneal epithelium was altered to an epidermal histo-architecture showing several superficial keratinized cells, cell infiltrations into the stroma, and several apoptotic cells. Skin markers keratin 1 and loricrin were positive, and surface disease was accompanied by deep stromal vascularization. Expression analysis for E-cadherin in KLEIP(-/-) corneas showed acellular areas in the squamous epithelium, indicating a progressive fragile corneal integrity. Removal of the virgin epithelium accelerated strongly development of the epithelial and stromal alterations, identifying mechanical injuries as the major trigger for corneal dystrophy formation and scarification in KLEIP(-/-) mice. CONCLUSIONS: The data identify KLEIP as an important molecule regulating corneal epithelial integrity.

Intracorneal hemorrhage in 19 dogs (22 eyes) from 2000 to 2010: a retrospective study.

OBJECTIVE: The aim of this retrospective study is to review clinical data on patients that suffered intracorneal hemorrhage (ICH), and the veterinary and human literature available for this condition. ANIMAL STUDIED: A search for ICH was performed within the clinical database of the Animal Health Trust. Nineteen cases were identified (22 eyes). PROCEDURES: The patient's age, breed, and gender were reviewed, together with etiology, location, treatment, and follow-up. The relevant data were compared with the Animal Health Trust (AHT) ophthalmology referral population for the same period of time (n=5555). RESULTS: Twenty-two eyes were affected. No breed or sex predisposition could be identified. Patients aged 10 years and above were more frequently affected when compared with the AHT ophthalmology referral population. ICH was recorded in all corneal quadrants, with the mid-peripheral cornea more often affected. Areas of corneas affected by the ICH showed long-term loss of transparency. Ocular diseases as a source of neovascularization varied from ocular surface to intraocular disease. Systemic diseases were investigated in some patients, and no concomitant disease could be linked to the development of ICH. CONCLUSIONS: Intracorneal hemorrhage is a rare condition associated with corneal neovasculature. As in the human ophthalmology literature, ICH could not be linked to a specific ocular or systemic disease. Severe complications described in humans with this condition, such as pupillary block or corneal perforation, were not seen in any of these canine patients. Canine ICH seem to reabsorb with time, with or without medical treatment. Surgical treatment was not required in any of our patients.