Increase In Corneal Thickness Research Articles

Analysis of influencing factors of corneal edema after phacoemulsification for diabetic cataract.

The paper aimed to explore the influence factors of corneal edema after phacoemulsification for diabetic cataracts. For this aim, 80 patients (80 eyes) with senile cataracts who underwent phacoemulsification implantation in our hospital from August 2021 to January 2022 were included in this study, including 39 males (48.75%) and 41 females (51.25%), with an average age of 70.35±5.22 years. The OCT system during ophthalmology was used to capture corneal OCT images in the center of the cornea in real time before the phacoemulsification (the phacoemulsification probe just entered the anterior chamber after the balanced saline left the separated nucleus), at the end of phacoemulsification (when the phacoemulsification ultrasound probe was still in the anterior chamber and the perfusion pressure did not change compared with that in the previous step), at the end of perfusion aspiration (after the perfusion aspiration probe left the anterior chamber), and after surgery (after the watertight incision is closed). The corneal thickness was measured at each time point using Photoshop software. AL, curvature and ACD were measured using IOL-Master bio-measurement technology, and ACD referred to the distance between the front surface of the cornea and the front surface of the lens. Endothelial cell density was measured using CIM-530 non-contact mirror microscope. A handheld rebound tonometer was used to measure intraocular pressure and optical coherence tomography was used to assess the macular area of the fundus. Fundus photography was performed with a non-diffuse fundus camera. The results indicated that the preoperative corneal thickness was 514.35±29.62 μm, and the average corneal thickness at the end of the operation was 535.26±30.29μm, which was increased by 20.91±1.67 μm compared with that before operation (P<0.05), and the increase rate of corneal thickness was 4.07%. The corneal thickness of patients tended to increase with the increase in operation time and intraocular operation time (P<0.05). The distribution of corneal edema-related features showed that 42.50% of patients had persistent edema at the time of cataract surgery. The median onset time of corneal edema in the remaining patients was 5.44 years (1.96-21.35 years for 90% CR). The higher the nuclear hardness, the more severe the cataract, and the higher APT, EPT, APE, and TST (P<0.05). The older the patient, the higher the grade of cataract nucleus, and the higher EPT, APE, and TST, the greater the intraoperative corneal thickening (P<0.05). The higher the maximum area of endothelial cells, the greater the intraoperative corneal thickness increase, the lower the corneal endothelial cell density and the greater the intraoperative corneal thickness increase (P<0.05). It was concluded that postoperative corneal edema in phacoemulsification surgery for diabetic cataracts is closely related to intraocular perfusion pressure, nuclear hardness of lens, the density of corneal endothelial cells, the energy of phacoemulsification and duration.

Comparison of rabbit corneal changes during different preservation techniques using optisol-GS and airlift

A previous study suggested that the airlift condition is superior to the Optisol-GS condition for preserving the limbal tissue of the human cornea. The purpose of this research is to investigate a new preservation device that preserves the cornea while separating epithelial and endothelial areas. The differences after preserving the corneal epithelium under different conditions were compared. A total of 24 corneas of New Zealand rabbits were divided into four groups in which the corneal epithelia were submersed in Optisol-GS or under airlift conditions for 1 and 2 weeks at 4 ^{circ }C. Transparency, optical coherence tomography (OCT), hematoxylin and eosin (H &E) staining, and epithelial migration tests were used to assess corneal status. The epithelial migration examination showed significantly greater migration ability after the airlift condition. Corneas in the 1-week Optisol-GS group were the most transparent, followed by the 1-week airlift group. OCT showed a progressive increase in corneal thickness to the end of the study. H &E staining showed that the epithelial cells retained intact cellular structure and morphology of the cells for both 1-week-preserved groups. However, there was disruption of the corneal epithelial cell structure for both 2-week-preserved groups. Corneal epithelium preserved under the hypothermic airlift condition was comparable to that under the Optisol-GS condition.

Effect of Solution pH on the Biomechanics of Intact Cornea From Inflation Tests

Purpose To investigate the effect of different pH phosphate buffer solution (PBS) drops on intact corneal biomechanics. Methods Intact rabbit cornea with a 3 mm scleral skirt was sampled and immediately applied in inflation tests within 5 min. After preconditioning, a stable loading cycle from 0.3 to 6 kPa was performed followed by a 10 min interval. During the interval, the samples were randomized into four groups, with one control group receiving no drops and three groups with PBS drops of pH 6.9, 7.4 or 7.9 administration on the surface once per minute. The pressure and displacement were collected at the baseline and 10, 20 and 30 min following the administration. Results Continuous corneal thickness increase was manifested following the administration of PBS but not in the control group. There was significant swelling-independent corneal modulus reduction after PBS administration, which occurred mainly in the first 10 min. PBS of pH 6.9 achieved significantly smaller modulus reduction than that with pH 7.4 PBS adjusted for thickness changes (p < 0.05). Pressure-modulus curve linear fitting demonstrated that the curve coefficient significantly reduced following PBS administration, and the coefficient decline was smallest with pH 6.9 PBS among three PBS administration groups (p < 0.05). Conclusions The study demonstrated that the PBS drops of various pH administration could decrease the corneal stiffness independent of corneal swelling. Following the PBS administration, the stiffness changes were more prominent as the posterior pressure increased, and the minimal effect was achieved with slightly acidic PBS. The research provides the essence for stabilizing the corneal biomechanical properties by regulating the pH value of tear film and intraocular pressure.

Novel Treatment Options for Corneal Edema

Introduction: The current treatment of corneal edema is limited to hyperosmotic saline mixtures. Usually the therapy consists of treatment with hypertonic 5% NaCl eye drops or 6% eye ointment. However, these only remain on the cornea for a short time because they are quickly removed by the tear film and blinking. This problem is partly addressed by adding hyaluronic acid to some pharmaceuticals. In this work, Sovermol as a carrier oil supplied with osmotically active substances, honey, icing sugar, Substance C188 and Prevor® substance X were investigated in an experimental setting as therapeutics for corneal edema. Material and Methods: In the Ex vivo Eye irritation Test (EVEIT), corneas can be examined under defined and stable biochemical conditions without blinking. Corneal edema can be simulated and examined using ultrasound pachymetry and Optical Coherence Tomography (OCT). Thus, we investigated the deswelling effect of the substances described above on 23 EVEIT corneas. Results: The mixtures, examined in this study, showed a significant reduction of corneal edema especially mixtures of Sovermol with Substance C188 were very promising as a new approach to treatment of corneal edema. As reference substance for corneal edema treatment ODM5® was used. Other mixtures, especially Honey and Prevor® substance X in DOL showed a sufficient reduction of corneal edema, while also damaging the corneal epithelium. While the mixture of DOL and powder sugar showed an increased corneal thickness and damaged Epithelium. Conclusion: The therapy of corneal edema with osmotically active substances as investigated here is a promising treatment for corneal edema. However, further pharmacological development is needed for application in patients.

Evaluation of the Corneal Endothelium Following Cataract Surgery in Diabetic and Non-Diabetic Patients.

The aim of this study was to evaluate the influence of phacoemulsification cataract surgery on the state of the corneal endothelium in diabetic versus non-diabetic patients. We compared the corneal cell morphology in 48 diabetics with good glycemic control and 72 non-diabetic patients before and after uneventful phacoemulsification. Corneal cell density, central corneal thickness, and hexagonality were measured preoperatively and post-surgery (at 1 and 4 weeks) by specular microscopy. The effect of age, gender, axial length, and anterior chamber depth on the parameters of the corneal endothelium were evaluated. We noticed a drop in the endothelial density in both groups postoperatively: a mean endothelial cell loss of 472.7 ± 369.1 in the diabetic group was recorded versus 165.7 ± 214.6 mean loss in the non-diabetic group after the first week. A significant increase in central corneal thickness was also noticed in both groups one week after phacoemulsification, but no statistical significance after 4 weeks in the diabetic group. In terms of cell hexagonality, statistically significant differences were noticed after 4 weeks in both groups. Overall, a significant difference between diabetic and non-diabetic population was noticed in terms of corneal endothelial cell loss after uneventful phacoemulsification cataract surgery. Routine specular microscopy and HbA1c evaluation is recommended before cataract surgery, while intraoperative precautions and high monitorisation in terms of pacho power intensity and ultrasound energy, along with a proper application of the dispersive viscoelastic substances are essential to reduce the risk of endothelial damage.

Central Corneal Thickness and Intraocular Pressure in Women With Gestational Diabetes Mellitus.

Pregnancy causes an increase in central corneal thickness (CCT) and a reduction in intraocular pressure (IOP), especially in the third trimester. However, there is very limited published data regarding CCT and IOP in gestational diabetes mellitus (GDM) on diet control. This study is aimed to compare the means of CCT and IOP between pregnant women with GDM on diet control, healthy pregnant women, and healthy non-pregnant women. This is a comparative cross-sectional study. A total of 184 women were recruited and divided into the following three groups: 61 pregnant women with GDM on diet control, 63 healthy pregnant women, and 60 healthy non-pregnant women as control. All subjects have undergone ocular examination during their 36-40 weeks of gestation. CCT measurement was done using a specular microscope and IOP measurement using a non-contact tonometer. Data from the right eye were analyzed. The mean age was 32 (4.0)years in GDM on diet control, 29 (3.0)years in healthy pregnant women, and 27 (5.4)years in healthy non-pregnant women. The number of gravidas was 2.5 (0.8) in women with GDM on diet control and 2.3 (0.8) in healthy pregnant women. There was a significant difference (p<0.05) in the mean CCT in women with GDM on diet control compared to healthy pregnant and healthy non-pregnant women. The mean IOP is significantly lower in both pregnant women with GDM on diet control and healthy pregnant groups, compared to the healthy non-pregnant women group. Women with GDM showed significantly thicker mean CCT than healthy pregnant and non-pregnant women. The mean IOP is significantly lower in both pregnant women with GDM on diet control and healthy pregnant groups, compared to the healthy non-pregnant women group.

Effect of TRPM8 Functional Loss on Corneal Epithelial Wound Healing in Mice.

To reveal the role of cold-sensing transient receptor potential melastatin 8 (TRPM8) channels in corneal epithelial wound healing. Cold sensitivity, tear production, corneal thickness, and corneal opacity assessments were used to evaluate the effect of Trpm8 knockout on the ocular surface. A corneal epithelial wounding model was generated by scraping the corneal epithelium once or multiple times using C57BL/6J (wild-type [WT]) and Trpm8-/- mice. The processes of corneal epithelial repair and corneal epitheliopathy were observed and recorded. Corneas were collected for sequencing, immunofluorescence staining, hematoxylin and eosin staining, and quantitative PCR. The perception of coldness, basal tear secretion, and corneal thickness were decreased in young Trpm8-/- mice compared with those in WT mice, except for the corneal sensitivity. Corneal opacity and increased corneal thickness were observed in aged Trpm8-/- mice. TRPM8 deficiency promoted corneal epithelial wound closure, consistent with the observed increase in Ki67-positive epithelial cells, and the pharmacological activation of TRPM8 in WT mice delayed corneal re-epithelization. After subjecting mice to multiple injuries, squamous metaplasia emerged in Trpm8-/- corneas, as verified by cytokeratin-1 and small proline-rich protein 1B-positive staining. The IFN-β and IFN-γ signaling pathways were significantly activated in Trpm8-/- mice, which was confirmed based on the up-regulated expression of the key mediators, signal transducer and activator of transcription-1 and phosphor-signal transducer and activator of transcription-1, as well as the induction of IFN-stimulated genes, compared with levels in WT mice. In corneal wound healing, the loss of TRPM8 function could promote epithelial repair, but predispose the cornea to epithelial lesions.

Diagnostic Algorithm for Surgical Management of Limbal Stem Cell Deficiency.

Limbal stem cell deficiency (LCSD) presents several challenges. Currently, there is no clearly defined systematic approach to LSCD diagnosis that may guide surgical tactics. The medical records of 34 patients with LSCD were analyzed. Diagnostic modalities included standard (visometry, tonometry, visual field testing, slit-lamp biomicroscopy with corneal fluorescein staining, Schirmer test 1, ultrasonography) and advanced ophthalmic examination methods such as anterior segment optical coherence tomography, in vivo confocal microscopy, impression cytology, and enzyme-linked immunoassay. Standard ophthalmological examination was sufficient to establish the diagnosis of LSCD in 20 (58.8%) cases, whereas advanced evaluation was needed in 14 (41.2%) cases. Depending on the results, patients with unilateral LSCD were scheduled to undergo glueless simple limbal epithelial transplantation (G-SLET) or simultaneous G-SLET and lamellar keratoplasty. Patients with bilateral LSCD with normal or increased corneal thickness were enrolled in the paralimbal oral mucosa epithelium transplantation (pLOMET) clinical trial. Based on the diagnostic and surgical data analyzed, the key points in LSCD diagnosis were identified, helping to guide the surgeon in selecting the appropriate surgical procedure. Finally, we proposed a novel step-by-step diagnostic algorithm and original surgical guidelines for the treatment of patients with LSCD.

Effect of conventional and orthokeratological hard contact lenses on anatomical and functional characteristics of the cornea

This study evaluated the potential effects of conventional hard contact lenses (HCL) and orthokeratological contact lenses (OKL) on anatomical and functional condition of the cornea in myopia correction. The study included 80 patients (159 eyes) with low, moderate and high myopia. Group 1 consisted of 40 patients (79 eyes) who used conventional HCL; group 2 included 40 patients (80 eyes) who used OKL. All patients underwent topographic keratometry, corneal pachymetry mapping (Pentacam, Oculus, Germany; Visante OCT, Carl Zeiss, Germany), high-order aberrometry (OPD Scan, Nidek, Japan), confocal microscopy (Confoscan 4, Nidek, Japan), evaluation of corneal biomechanical properties (ORA, Reichert Technologies, USA) and corneal light scattering (Pentacam, Oculus, Germany). Examinations were taken before the treatment started and after 8-12 months of contact lens wear. Group 1 showed corneal thickness increase in all zones (by 0.9-1.1%), no significant changes in corneal refraction, and increase in corneal hysteresis and corneal resistance factor. OKL wear led to a significant flattening of anterior surface of the cornea and steepening of its paracentral area, decrease in central corneal thickness (by 2.8%) and increase in mid-peripheral thickness (by 2.2%). No significant changes in posterior corneal surface were observed in the study patients. More significant increase in higher-order aberrations and the degree of light scattering was observed in group 2, while changes in subepithelial nerve plexus and stromal structure were more significant in group 1. Long-term OKL wear shows more significant morphological and functional corneal changes compared to RGP lens.

The impacts of contact lenses on the short- and long-term biochemical parameters of tear films and corneal thickness

Introduction: To investigate the effects of long- and short-term use of different types of contact lenses on corneal metabolism and corneal thickness. Materials and Method: The participants were divided into two groups in the study. In the first group, 20 of the 42 patients were administered a rigid gas-permeable lens (RGPL) with a Dk value of 92x10-11, while the remaining wore a soft contact lens with a water content of 38%. We then explored their Lactate Dehydrogenase (LHD) levels to evaluate the hypoxic effect on tear films in short- (8 hours) and long-term (2nd, 3rd, 5th months) and albumin levels to assess mechanical trauma. In the second group, the corneal thickness was measured using a Haag-Streit optical pachymeter before and at the 8th hour and 2nd month following the first set of lenses, and LDH and albumin values were simultaneously evaluated in tear film. Results: The results yielded no significant increase in tear film LDH and albumin levels in the short- and long-term in both the RGPL and the soft contact lens groups with similar age and sex distribution. In the second part, the corneal thickness measurements resulted in an increase of 5.5% in the RGPL group and 3.63% in the soft lens group at the 8th hour of lens use. However, the groups did not significantly differ by baseline corneal thickness at the 2nd-month follow-up. Similarly, there was no significant increase in LDH and albumin levels in the tear film samples of the same group. Conclusion: The absence of a long-term increase in corneal thickness and no elevated levels of albumin and LDH in tear films indicate that contact lenses fit corneal physiology.

Influence of 0.002% Omidenepag Isopropyl on Intraocular Pressure and the Cornea in Normal Tension Glaucoma.

Although Omidenepag isopropyl drops elicited stable intraocular pressure reductions in NTG patients, transient changes in refraction and corneal endothelial cells, significant increase of central corneal thickness, and corneal erosion should be considered. To analyze the efficacy and safety of 0.002% omidenepag Isopropyl (OMDI) eye drops in patients with normal tension glaucoma (NTG). Medical records for 62 eyes treated with OMDI for ≥6 months were analyzed. Intraocular pressure (IOP), refraction, keratometry, central corneal thickness (CCT), endothelial cell count, coefficient of variation of endothelial cell area (CV), corneal erosion, and central retinal thickness were compared at baseline and 1, 3, and 6 months. IOP significantly decreased from 13.4±3.8 to 11.9±3.0, 11.7±2.9, and 12.2±3.3mmHg at each follow-up ( P <0.001). Endothelial cell count did not change, but CV transiently increased from 12.6 to 17.0 at 1 month, CCT increased from 531.5 to 538.4μm, myopia changed from -1.5 to -1.9 D, and keratometry changed from 44.5 to 44.7 D. CV, myopia, and keratometry recovered to baseline at 6 months; however, CCT remained high. Significant corneal erosion was observed at 6 months. Central retinal thickness changes were not observed. There were improvements in prostaglandin-associated skin pigmentation (86.7%), eyelash elongation (40.0%), and deepening of the upper eyelid sulcus and ptosis (~30%) at 3 months after exchange to OMDI. Adverse reactions were corneal erosion (27.4%), corneal thickening (21.0%), conjunctival hyperemia (11.3%), photophobia (5.7%), blurred vision (5.7%), and anterior chamber cells (4.8%). OMDI eye drops elicited significant and stable IOP reductions after 6 months in NTG patients with low IOP. However, transient myopic and corneal endothelial cell changes, development of corneal thickening, and corneal erosion should be considered when using OMDI.

Novel DCN Mutation in Armenian Family With Congenital Stromal Corneal Dystrophy.

Congenital stromal corneal dystrophy (CSCD) is a rare congenital, dominantly inherited disorder characterized by diffuse stromal opacification associated with mutations in the decorin gene ( DCN ). As only 5 families with genetically confirmed CSCD have been reported, the identification of a novel pedigree provides the opportunity to better characterize the phenotype and genetic basis. An Armenian family with individuals in 4 consecutive generations demonstrated clinical features consistent with CSCD. Consented individuals underwent slit lamp examination, optical coherence tomography, and confocal microscopy. Genomic DNA was collected from saliva and all coding and adjacent intronic regions of DCN were sequenced. In silico analysis was performed for identified mutation(s). Excised corneal tissue underwent light, electron microscopic, and immunohistochemical evaluation. Affected individuals demonstrated bilateral, diffuse, panstromal corneal opacification. Three of the 6 individuals diagnosed with CSCD underwent genetic analysis; all demonstrated a novel heterozygous frameshift deletion in exon 8 of DCN (p.His317Thrfs*11), predicted to cause a 33 amino acid truncation and to be damaging and disease causing by SIFT and MutationTaster. Light and electron microscopic examination of an excised cornea demonstrated increased corneal thickness, stromal scarring, keratocyte loss, and an irregularity of lamellar collagen spacing and fibril formation. Immunofluorescent examination demonstrated increased DCN immunostaining, predominantly in the widened interlamellar spaces. We report only the sixth pedigree with genetically confirmed CSCD, associated with a novel DCN frameshift mutation. The clinical evaluation, multimodal imaging, and histopathologic assessment in this family with CSCD broaden our understanding of this rare corneal disease.

New findings on the immune response following corneal transplantation

AbstractWe performed a multi‐centre, cross‐sectional analysis of the current immunological status of human full thickness (FT) and posterior lamellar (PL) corneal transplant (CT) recipients and control subjects using multiple technology platforms. The primary goal of this study was to define pathways associated with adverse immune responses to corneal transplantation and to generate and compare comprehensive, pathway‐based profiles of immune activity in CT acute rejection (AR). The secondary goal was to identify a composite biomarker of CT AR. Clinical details, including a comprehensive clinical examination, and blood samples, enabling analysis of peripheral blood mononuclear cell (PBMC) DNA, RNA and phenotype, were collected from adults with clinically diagnosed AR of FL‐CT (n = 35) and PL‐CT (n = 21) along with Stable CT recipients (n = 177) and adults with non‐transplanted corneal disease (n = 40). For those with AR, additional samples were collected 3 months later. CT acute rejection was clinically diagnosed and defined as precipitates on the corneal graft but not on the peripheral recipient cornea, either scattered or in the form of a Khodadoust line along with an increase in central corneal thickness. Immune cell analysis was performed by whole‐genome microarrays (whole blood) and high dimensional multi‐colour flow cytometry (peripheral blood mononuclear cells). For both, no activation signature was identified within the B cell and T cell repertoire at the time of AR diagnosis. Nonetheless, in FT‐ but not PL‐CT recipients, AR was associated with differences in B cell maturity and regulatory CD4+ T‐cell frequency compared to stable allografts. Our results suggest that, in contrast to solid organ transplants, genetic or cellular assays of peripheral blood are unlikely to be clinically exploitable for prediction or diagnosis of AR. However, further investigation of circulating B cell and T cell subpopulations may provide insights into the regulation of anti‐donor immune response in human CT recipients with differing AR risk.

Protective effect of Tisochrysis lutea on dry eye syndrome via NF-κB inhibition

Dry eye syndrome (DES) affects the cornea, causes pain and hypersensitivity to light. Although inflammation and endoplasmic reticulum stress are known to be involved, the detailed mechanisms remain unknown. DES is characterized by a decrease in corneal thickness, tear volume, and lacrimal gland size, and damage to corneal cells. Tisochrysis lutea is a microalga that has been shown to reduce immune factors. Therefore, we hypothesized that T. lutea could ameliorate DES. We investigated the role of T. lutea in scopolamine-induced DES in BALB/c mice. Oral administration of T. lutea increased corneal thickness, tear volume, and size of the corneal cells, and reduced damage to the corneal cells. Furthermore, treatment of ARPE-19 human retinal pigmented epithelial cells with T. lutea reduced expression of the inflammatory factor, NF-κB, MAPK, and AKT. T. lutea may be used therapeutically to reduce the symptoms of DES.

Fresh Human Myopic Lenticule Intrastromal Implantation for Keratoconus Using SMILE Surgery in a Long-term Follow-up Study: Ultrastructural Analysis by Transmission Electron Microscopy.

To investigate new intrastromal histological structures that develop after myopic human lenticular implantation in keratoconus with femtosecond laser-assisted small incision lenticule extraction (SMILE) surgery using transmission electron microscopy. Sixty eyes with advanced keratoconus indicated for corneal transplantation were included in this study. Fresh myopic lenticular implants were placed in all eyes through SMILE surgery. Lenticular implants were extracted from patients with myopic refractive errors of the cornea, untreated keratoconus, and treated keratoconus following 1, 2, and 3 years of surgery. These five lenticular samples were examined under the electron microscope and compared. Disorganized and thinned collagen fibers were observed in the stroma with degenerative stromal cells (telocyte-like cells and keratocytes) in the keratoconic cornea. Apoptotic bodies and cell debris were easily observed near the disorganized fibers. In contrast, the myopic refractive error of the control and treatment groups demonstrated well-organized parallel lamellar structures. Healthy keratocytes and telocyte-like cells were observed in samples obtained 1, 2, and 3 years after lenticular implantation. Thus, telocyte-like cells may be activated by appropriate stimuli, such as stem cells, and be involved in stromal regeneration. Fresh myopic intrastromal lenticular implantation is a safe, economical, and reliable technique that leads to increased corneal thickness, improved visual acuity, and the regeneration of healthy keratocytes and telocyte-like cells that are involved in stromal regeneration. [J Refract Surg. 2022;38(8):520-528.].

Bilateral penetrating keratoplasty revealed advanced glaucoma in a case of mucopolysaccharidosis type VI

Introduction: We report a case of a patient with mucopolysaccharidosis (MPS) type VI disease who underwent bilateral penetrating keratoplasty. The insight into deeper ocular structures after successful keratoplasty enabled the diagnosis of glaucoma. Case Report: A 24-year-old male patient with genetically confirmed MPS VI disease was referred for ophthalmological co-assessment to our Department of Ophthalmology. The patient presented with low visual acuity of 6/200 in both eyes, and increased corneal thickness. The bilateral intraocular pressure was difficult to evaluate in association with the corneal thickness and rigidity. Due to total corneal opacification bilateral penetrating keratoplasty was performed. The successful keratoplasty allowed proper funduscopy and further diagnostic measurements leading to the diagnosis of advanced glaucoma. Conclusion: Although MPS VI is an orphan disease, intravenously applied enzyme replacement therapy with galsulfase has been established as a successful treatment. However, systemically administered therapy with galsulfase does not reduce or affect ocular symptoms and manifestations. The case demonstrates the high impact of early and regularly ophthalmic co-assessment in MPS VI patients, especially keeping in mind that not only corneal involvement can be present in MPS patients. Further-more, preservation of visual acuity is of high importance for participating in social and professional life.

3D biomaterial P scaffolds carrying umbilical cord mesenchymal stem cells improve biointegration of keratoprosthesis

Biointegration of a keratoprosthesis (KPro) is critical for the device stability and long-term retention. Biointegration of the KPro device and host tissue takes place between the surrounding corneal graft and the central optic (made by poly (methyl methacrylate)). Our previous clinical results showed that auricular cartilage reinforcement is able to enhance the KPro biointegration. However, the auricular cartilage is non-renewable and difficult to acquire. In this study, we developed a novel type of biomaterial using a three-dimensional porous polyethylene glycol acrylate scaffold (3D biological P-scaffold) carrier with chondrocytes differentiated from induced human umbilical cord mesenchymal stem cells (hUC-MSCs) and tested in rabbit corneas. The results showed hUC-MSCs bear stem cell properties and coule be induced into chondrocytes, P-scaffold is beneficial to the growth and differentiation of hUC-MSCs both in vivo and in vitro. Besides, after implanting the P-scaffold into the corneal stroma, no serious immune rejection response, such as corneal ulcer or perforation were seen, suggested a good biocompatibility of P-scaffold with the corneal tissue. Moreover, after implanting P-scaffold in together with the differentiated chondrocytes into the rabbit corneal stroma, they significantly increased corneal thickness and strengthened the host cornea, and chondrocytes could stably persist inside the cornea. In summary, the 3D biological P-scaffold carrying differentiated hUC-MSCs could be the preferable material for KPro reinforcement.

Crioterapia después de queratectomía por carcinoma de células escamosas en un perro: Reporte de caso

Ocular neoplasms represent a growing part of the veterinary ophthalmic routine. Squamous cell carcinoma (SCC) is described as rare in dogs, but it has been on the increase due to different etiologies. The presence of chronic keratitis and exposure to ultraviolet radiation are some of these factors. In the present study, the objective was to report cryotherapy, a technique that was effective in the treatment of squamous cell carcinoma (SCC). A 13-year-old mixed-breed dog was seen at a veterinary center in Londrina-PR, with a neoformation in the right eye. Ophthalmic examination revealed no other changes. Direct and consensual pupillary reflexes were present and intraocular pressure was 12 mmHg. Slit lamp bio-microscopy was performed, which showed increased corneal thickness and superficial corneal vascularization with neoformation infiltrating the epithelium and small part of the stroma. On that account, the diagnosis of SCC was made which led to the decision to remove the neoplasm. Thus, a lamellar keratectomy was performed associated with the cryotherapy technique, through temporary tarsorrhaphy. The suspicion of carcinoma is based on the macroscopic morphological basis of the lesion and its location, but the definitive diagnosis is made through histopathology with microscopic examination of the injured tissue. It may be concluded that through clinical history, described etiologies and histopathological examination are essential for the diagnosis of SCC.

Cataract surgery in patients with Fuchs’ dystrophy and corneal decompensation indicated for Descemet's membrane endothelial keratoplasty

The availability of corneal donor tissue is limited in most developing countries. This study evaluated whether patients with coexisting cataract and Fuchs’ dystrophy with corneal decompensation awaiting Descemet’s membrane endothelial keratoplasty (DMEK) benefited from phacoemulsification. This is a retrospective case–control study which included patients with Fuchs’ dystrophy and evidence of corneal decompensation awaiting DMEK. Best-corrected visual acuity (BCVA) and central corneal thickness (CCT) were documented at baseline (pre-cataract surgery in the case group, or at the time of transplantation registry in the control group), 1-month and pre-DMEK. A total of 16 phakic patients with visually significant cataracts had cataract surgery during the study period, and 15 pseudophakic patients were included as controls. There was no significant difference with regard to BCVA at baseline, 1-month or pre-DMEK between the case and control groups. Similarly, no significant difference in CCT was found at baseline, 1-month or pre-DMEK. In the case group, 4 patients with improved visual acuity post-cataract surgery chose to defer DMEK. After stratification, statistical analysis showed significantly better BCVA in the deferred group (n = 4) at 1-month post-cataract surgery, compared to the DMEK group (n = 12) (0.21 ± 0.21 vs. 0.86 ± 0.29 LogMAR, P = 0.004). The other parameters, including baseline BCVA and CCT at any time point documented, were not statistically different. In conclusion, in patients with Fuchs’ dystrophy and decompensated corneas awaiting transplantation, phacoemulsification did not lead to significant increase of corneal thickness nor deterioration of visual acuity. A few patients achieved satisfactory vision after cataract surgery and deferred endothelial keratoplasty.

Correlation of Clinical Fibrillar Layer Detection and Corneal Thickness in Advanced Fuchs Endothelial Corneal Dystrophy.

Central subendothelial geographic deposits are formed as a fibrillar layer (FL) in advanced Fuchs endothelial corneal dystrophy (FECD). Previous studies demonstrated a significant decrease in corneal endothelial cell (CEC) density and an increase in focal corneal backscatter in the FL area. The present study investigated the association of the FL with edema formation and its localization. Patients (n = 96) presenting for Descemet membrane endothelial keratoplasty (DMEK) for advanced FECD were included. Slit-lamp biomicroscopy with FECD grading was followed by Scheimpflug imaging with en face backscatter analysis and pachymetric analysis. FL dimensions were measured, and correlation with pachymetric values was performed. An FL was detected in 74% of all eyes (n = 71). Pachymetric values in FL-positive versus FL-negative eyes were for corneal thickness at the apex (ACT) 614 ± 52 µm and 575 ± 46 µm (p = 0.001), for peripheral corneal thickness at 1 mm (PCT1mm) 616 ± 50 µm and 580 ± 44 µm (p = 0.002), for PCT2mm 625 ± 48 µm and 599 ± 41 µm (p = 0.017), for PCT3mm 651 ± 46 µm and 635 ± 40 µm (p = 0.128) and for PCT4mm 695 ± 52 µm and 686 ± 43 µm (p = 0.435), respectively. Correlation analysis indicated a weak correlation for the FL maximum vertical caliper diameter with ACT and PCT1mm values but no further relevant correlations. In FL-positive eyes, increased focal corneal backscatter and increased corneal thickness showed primarily central and inferotemporal localization. In conclusion, Scheimpflug imaging shows an association of the FL with increased corneal thickness in advanced FECD and shows localization of the FL and increased corneal thickness in the central and inferotemporal region. This may provide important information for progression assessment and therapeutic decision making in FECD patients in the future.