A Case of Paracentral Corneal Perforation Treated with One-Bite Mini-Keratoplasty.

A 61-year-old man presented with corneal perforation of 1.0 mm in diameter in his right eye caused by a metallic foreign body fragment. We used the "one-bite mini-keratoplasty" technique, which uses a cornea patch with a single host-graft-host suture to stop aqueous humor leakage. Postoperatively, the graft was completely epithelialized. The suture was removed and the use of soft contact lens was discontinued. Postoperative best-corrected visual acuity (BCVA) recovered to 180/200 and corneal astigmatism was 0.6 diopters. The postoperative course was unremarkable, but corneal perforation recurred due to an ocular contusion at 17 months. He was reoperated using the same technique. His BCVA was 160/200 and corneal astigmatism was 1.1 diopters after reoperation. Despite performing this surgical technique twice for corneal perforation, optimal visual function was maintained even after 2 years. For paracentral corneal perforations, our simple technique may reduce astigmatism and maintain high visual function.

Deep Neural Network-Based Method for Detecting Obstructive Meibomian Gland Dysfunction With in Vivo Laser Confocal Microscopy.

PURPOSE: To evaluate the ability of deep learning (DL) models to detect obstructive meibomian gland dysfunction (MGD) using in vivo laser confocal microscopy images. METHODS: For this study, we included 137 images from 137 individuals with obstructive MGD (mean age, 49.9 ± 17.7 years; 44 men and 93 women) and 84 images from 84 individuals with normal meibomian glands (mean age, 53.3 ± 19.6 years; 29 men and 55 women). We constructed and trained 9 different network structures and used single and ensemble DL models and calculated the area under the curve, sensitivity, and specificity to compare the diagnostic abilities of the DL. RESULTS: For the single DL model (the highest model; DenseNet-201), the area under the curve, sensitivity, and specificity for diagnosing obstructive MGD were 0.966%, 94.2%, and 82.1%, respectively, and for the ensemble DL model (the highest ensemble model; VGG16, DenseNet-169, DenseNet-201, and InceptionV3), 0.981%, 92.1%, and 98.8%, respectively. CONCLUSIONS: Our network combining DL and in vivo laser confocal microscopy learned to differentiate between images of healthy meibomian glands and images of obstructive MGD with a high level of accuracy that may allow for automatic obstructive MGD diagnoses in patients in the future.

Comparison of semi-automated center-dot and fully automated endothelial cell analyses from specular microscopy images.

PURPOSE: To evaluate two specular microscopy analysis methods across different endothelial cell densities (ECDs). METHODS: Endothelial images of one eye from each of 45 patients were taken by using three different specular microscopes (three replicates each). To determine the consistency of the center-dot method, we compared SP-6000 and SP-2000P images. CME-530 and SP-6000 images were compared to assess the consistency of the fully automated method. The SP-6000 images from the two methods were compared. Intraclass correlation coefficients (ICCs) for the three measurements were calculated, and parametric multiple comparisons tests and Bland-Altman analysis were performed. RESULTS: The ECD mean value was 2425 ± 883 (range 516-3707) cells/mm2. ICC values were > 0.9 for all three microscopes for ECD, but the coefficients of variation (CVs) were 0.3-0.6. For ECD measurements, Bland-Altman analysis revealed that the mean difference was 42 cells/mm2 between the SP-2000P and SP-6000 for the center-dot method; 57 cells/mm2 between the SP-6000 measurements from both methods; and -5 cells/mm2 between the SP-6000 and CME-530 for the fully automated method (95% limits of agreement: - 201 to 284 cell/mm2, - 410 to 522 cells/mm2, and - 327 to 318 cells/mm2, respectively). For CV measurements, the mean differences were - 3, - 12, and 13% (95% limits of agreement - 18 to 11, - 26 to 2, and - 5 to 32%, respectively). CONCLUSIONS: Despite using three replicate measurements, the precision of the center-dot method with the SP-2000P and SP-6000 software was only ± 10% for ECD data and was even worse for the fully automated method. CLINICAL TRIAL REGISTRATION: Japan Clinical Trials Register ( http://www.umin.ac.jp/ctr/index/htm9 ) number UMIN 000015236.

Suppression of fibrosis in human pterygium fibroblasts by butyrate and phenylbutyrate.

AIM: To evaluate the antifibrogenic effects of butyrate or phenylbutyrate, a chemical derivative of butyrate, in human pterygium fibroblasts. METHODS: Human pterygium fibroblasts obtained from patient pterygium tissue were treated with butyrate or phenylbutyrate for 48h. Expression of α-smooth muscle actin, collagen I, collagen III and matrix metalloproteinase-1 mRNA was measured by quantitative real-time reverse transcription polymerase chain reaction, and acetylated histone was evaluated by Western blotting. RESULTS: Butyrate inhibited α-smooth muscle actin, type III collagen and matrix metalloproteinase-1 expressions, and phenylbutyrate inhibited types I and III collagen and matrix metalloproteinase-1 expressions without changing cell viability as well as both of these increased histone acetylation. These results suggested that butyrate and phenylbutyrate suppress fibrosis through a mechanism involving histone deacetylase inhibitor. CONCLUSION: This indicates that butyrate or phenylbutyrate have antifibrogenic effects in human pterygium fibroblasts and could be novel types of prophylactic and/or therapeutic drugs for pterygium, especially phenylbutyrate, which does not have the unpleasant smell associated with butyrate.

The role of oxidative stress and inflammation in conjunctivochalasis.

Purpose. To investigate the status of oxidative stress and histopathologic alterations in patients with conjunctivochalasis and compare the findings with those in healthy control subjects. Methods. Eleven patients (n = 20 eyes) with Yokoi grade 3 conjunctivochalasis and 11 health control subjects (n = 22 eyes) were prospectively recruited. ELISA for tear hexanoyl-lysine (HEL) and inflammatory cytokines, tear film break-up time tests, Schirmer test measurements, and fluorescein and rose bengal vital staining were performed. Conjunctival specimens obtained during surgery for conjunctivochalasis and cataract underwent immunohistochemical staining for HEL+8-OHdG, MMP-3, and MMP-9, and positively stained cells were counted. Transmission electron microscopy was also performed, with staining for elastic fibers in the conjunctival stroma. Results. The mean tear stability and vital staining scores were significantly worse in the conjunctivochalasis patients than in the control subjects. The tear HEL and tear cytokine levels showed significantly higher values in eyes with conjunctivochalasis. IL-1beta and IL-6 levels showed a significant correlation with corneal epithelial damage. IL-1beta and TNFalpha showed a significant correlation with 8-OHdG-stained cell counts. Specimens from patients with conjunctivochalasis revealed a significantly higher number of cells positively stained for HEL, 8-OHdG, MMP-3, and MMP-9 than did specimens from age- and sex-matched control subjects. Transmission electron microscopy showed decreased intercellular cohesiveness, with the conjunctival stroma showing an accumulation of elastic fibers. Conclusions. Lipid and DNA oxidative stress were present in the conjunctiva. Increased tear inflammation seemed to coexist with loss of conjunctival epithelial cohesiveness and increased collagenolytic activity, which may explain the conjunctival laxity observed in patients with conjunctivochalasis.

Evaluation of conjunctival inflammatory status by confocal scanning laser microscopy and conjunctival brush cytology in patients with atopic keratoconjunctivitis (AKC).

PURPOSE: To elucidate the status of the conjunctival inflammation in atopic keratoconjunctivitis (AKC) using laser scanning confocal microscopy and compare the relevant findings with conjunctival brush cytology in a prospective controlled study. METHODS: Twenty eyes from 20 AKC patients as well as 16 eyes from 16 age and sex matched normal subjects were studied. The subjects underwent tear film break-up time (BUT), fluorescein and Rose Bengal staining of the ocular surface, conjunctival confocal microscopy, Schirmer test, and brush cytology. Brush cytology specimens and in vivo confocal microscopy scans underwent evaluation for inflammatory cell densities. RESULTS: Brush cytology specimens and in vivo confocal microscopy scans from AKC patients revealed significantly higher numbers of inflammatory cells (p<0.05). Conjunctival inflammatory cell density showed a negative correlation with tear stability and a positive correlation with vital staining scores and conjunctival injection grades. The extent of conjunctival inflammation assessed by in vivo confocal microscopy showed a strong positive linear correlation with the inflammation status evaluated by brush cytology. The corneal inflammatory cell density assessed by in vivo confocal microscopy showed a significant negative correlation with tear stability and a positive linear correlation with corneal fluorescein staining. CONCLUSIONS: Confocal scanning laser microscopy is an efficient, noninvasive, and a promising tool for the quantitative assessment of conjunctival inflammation, a parameter of this new technology which correlated well with subjective and objective ocular surface clinical findings.

Effects of various eye drops on corneal wound healing after superficial keratectomy in rabbits.

PURPOSE: The effects of various eye drops on corneal wound healing, particularly in the subepithelial haze area, were investigated histologically following superficial keratectomy in rabbits. METHODS: Mechanical superficial keratectomy was performed in rabbit eyes. Tranilast, betamethasone, hyaluronic acid, and diclofenac eye drops were administered after the procedure. Physiological saline was used as a control. Corneas were excised 1, 2, 3, and 4 weeks after keratectomy, labeled with 3H-thymidine or 3H-proline, and subjected to autoradiography. RESULTS: In the control and diclofenac groups, corneal haze occurred 3 weeks after keratectomy. Histological examination revealed an accumulation of proliferating keratocytes and active synthesis of collagen in the subepithelial area. In the tranilast and betamethasone groups, formation of corneal haze was reduced compared to the controls. The proliferation of keratocytes and the production of collagen in the corneal stroma were inhibited by these drugs. In the hyaluronic acid group also, corneal haze was decreased. In this group, although the proliferation of keratocytes was activated compared to the controls, abnormal accumulation of keratocytes in the subepithelial area was not detected. CONCLUSIONS: Tranilast and betamethasone decrease the formation of subepithelial haze by inhibiting keratocyte proliferation and synthesis of extracellular matrix in the corneal stroma. Hyaluronic acid, on the other hand, inhibits subepithelial haze by promoting physiologic wound healing.

Corneal disorders in KKAy mouse: a type 2 diabetes model.

PURPOSE: To observe the clinical and histopathological changes occurring in corneas of KKAy mice, a model of type 2 diabetes, and to elucidate the possible mechanisms involved in these changes. METHODS: Corneal epithelial cell proliferation was analyzed in KKAy and age-matched non-diabetic C57BL/6J control mice using (3)H-thymidine autoradiography. Clinical examination and histopathological analysis were also conducted on both types of mice. RESULTS: KKAy mice showed a significant elevation in blood glucose concentration and body weight compared to age-matched control mice. Fragile corneal epithelial cell attachment and subepithelial opacities were observed in the central area of the cornea of 10-week-old KKAy mice. Corneal epithelial cell proliferation decreased significantly in the 16-week-old KKAy mice. Histological study in the older KKAy mice groups revealed the presence of subepithelial deposits, widening of the intracellular spaces between corneal epithelial cells with poor adherence to the basement membrane (BM) and thickening of the BM itself. At the central area of the cornea, remnants of cell components with deposits and lacuna formation were observed, perhaps secondary to the continuous presence of poor adhesion and detachment of epithelial cells in the area. In the 50-week and older KKAy mice, thinning and atrophy of the corneal epithelial cell layer became more prominent at the central cornea with increases in deposition of materials, blood vessel invasion and activation of keratocytes. The deposits were stained black by von Kossa's method, indicating the presence of tissue calcium. Type IV collagen immunoreactivity was observed not only in the corneal and conjunctival BM but also between the stroma, particularly around the central cornea and in the walls of invading vessels. Laminin staining was intense at the BM around the central cornea, and in the walls of invading vessels along the stroma. Pyrraline, which is one of the major components of advanced glycation end products, was also present in the stroma, and around blood vessels. All these corneal changes were not observed with aging in the age-matched C57BL/6J mice. CONCLUSIONS: Our findings provide evidence of the existence of corneal disorders in KKAy mice. These observations may provide useful information for the explanation of the mechanisms involved in corneal disorders in non-insulin-dependent diabetes mellitus patients.

[Effects of various eye drops on corneal wound healing after superficial keratectomy in rabbits].

PURPOSE: The effects of various eye drops on corneal wound healing, particularly in the subepithelial haze area, investigated histologically following superficial keratectomy in rabbits. MATERIAL AND METHODS: Mechanical superficial keratectomy was performed in rabbit eyes. Tranilast, betamethasone, hyaluronic acid and diclofenac eye drops were administered after the procedure. Physiological saline was used as a control. Corneas were excised 1, 2, 3, and 4 weeks after keratectomy, labeled with 3H-thymidine or 3H-proline, and subjected to autoradiography. RESULTS: In the control and diclofenac groups, corneal haze occurred three weeks after keratectomy. Histological examination revealed accumulation of proliferating keratocytes and active synthesis of collagen in the subepithelial area. In the tranilast and betamethasone groups, formation of corneal haze was reduced compared to the controls. The proliferation of keratocytes and the production of collagen in the corneal stroma were inhibited by these drugs. In the hyaluronic acid groups, corneal haze was decreased. In this group, although the proliferation of keratocytes was activated compared to the controls, abnormal accumulation of keratocytes in the subepithelial area was not detected. CONCLUSION: Tranilast and betamethasone decrease the formation of subepithelial haze by inhibiting keratocyte proliferation and synthesis of extracellular matrix in the corneal stroma. Hyaluronic acid, on the other hand, inhibits subepithelial haze by promoting physiologic wound healing.