Classifications of anterior segment structure of congenital corneal opacity in infants and toddlers by ultrasound biomicroscopy and slit-lamp microscopic photographs: an observational study.

BACKGROUND: The structural features have an impact on the surgical prognosis for congenital corneal opacity (CCO). The structural classification system of CCO, however, is lacking. Based on data from ultrasound biomicroscopy (UBM) findings in infants and toddlers with CCO, this research proposed a classification system for the anterior segment structure severity. METHODS: Medical records, preoperative UBM images and slit-lamp photographs of infants and toddlers diagnosed with CCO at University Third Hospital between December 2018 and June 2022 were reviewed. According to the anterior segment structural features observed in UBM images, eyes were classified as follows: U1, opaque cornea only; U2, central anterior synechia; U3, peripheral anterior synechia combined with angle closure; and U4, aniridia or lens anomaly. The opacity appearance and corneal vascularization density observed in slit-lamp photographs were assigned grades according to previous studies. The extent of vascularization was also recorded. The corresponding intraocular anomaly classifications and ocular surface lesion severity were analysed. RESULTS: Among 81 eyes (65 patients), 41 (50.6%) were right eyes, and 40 (49.4%) were left eyes. The median age at examination was 6.91 months (n = 81, 1.00, 34.00). Two (2.5%) of the 81 eyes were classified as U1, 20 (24.7%) as U2, 22 (27.2%) as U3a, 11 (13.6%) as U3b and 26 (32.1%) as U4. Bilateral CCO eyes had more severe UBM classifications (P = 0.019), more severe dysgenesis (P = 0.012) and a larger angle closure (P = 0.009). Eyes with more severe UBM classifications had higher opacity grades (P = 0.003) and vascularization grades (P = 0.014) and a larger vascularization extent (P = 0.001). Eyes with dysgenesis had higher haze grades (P = 0.012) and more severe vascularization (P = 0.003 for density; P = 0.008 for extent), while the angle closure range was related to haze grade (P = 0.013) and vascularization extent (P = 0.003). CONCLUSIONS: This classification method based on UBM and slit-lamp photography findings in the eyes of CCO infants and toddlers can truly reflect the degree of abnormality of the ocular surface and anterior segment and is correlated with the severity of ocular surface anomalies. This method might provide meaningful guidance for surgical procedure design and prognostic determinations for keratoplasty in CCO eyes.

Three-dimensional in vivo evaluation of the cornea in patients with unilateral posterior interstitial keratitis.

Purpose: The purpose of this study was to investigate the in vivo morphologic features of the cornea in patients with unilateral posterior interstitial keratitis. Methods: Seven eyes of 7 patients with unilateral posterior interstitial keratitis were examined by slit-lamp biomicroscopy, anterior segment optical coherence tomography (AS-OCT), and in vivo confocal microscopy (IVCM). The imaging features of the cornea were evaluated and analyzed. Results: By slit-lamp examination, the posterior corneal stromal opacities were observed in all 7 eyes, and deep neovascularization in 4 eyes. The posterior stromal opacities showed higher reflectivity with an intact overlying epithelium by AS-OCT and did not invade the Bowman's layer in all cases. IVCM revealed highly reflective dispersed microdots, needle-shaped bodies, and increased reflectivity of keratocytes in the lesion site in all patients. Active Langerhans cells and an attenuated subbasal nerve plexus were observed in 5 eyes. After treatment, the active Langerhans cells disappeared; however, highly reflective microdots and needle-shaped bodies remained. Conclusion: The three-dimensional evaluation of slit-lamp biomicroscopy, AS-OCT, and IVCM may help in the early diagnosis of patients with posterior interstitial keratitis.

Fully automated grading system for the evaluation of punctate epithelial erosions using deep neural networks.

PURPOSE: The goal was to develop a fully automated grading system for the evaluation of punctate epithelial erosions (PEEs) using deep neural networks. METHODS: A fully automated system was developed to detect corneal position and grade staining severity given a corneal fluorescein staining image. The fully automated pipeline consists of the following three steps: a corneal segmentation model extracts corneal area; five image patches are cropped from the staining image based on the five subregions of extracted cornea; a staining grading model predicts a score for each image patch from 0 to 3, and automated grading score for the whole cornea is obtained from 0 to 15. Finally, the clinical grading scores annotated by three ophthalmologists were compared with automated grading scores. RESULTS: For corneal segmentation, the segmentation model achieved an intersection over union of 0.937. For punctate staining grading, the grading model achieved a classification accuracy of 76.5% and an area under the receiver operating characteristic curve of 0.940 (95% CI 0.932 to 0.949). For the fully automated pipeline, Pearson's correlation coefficient between the clinical and automated grading scores was 0.908 (p<0.01). Bland-Altman analysis revealed 95% limits of agreement between the clinical and automated grading scores of between -4.125 and 3.720 (concordance correlation coefficient=0.904). The average time required for processing a single stained image during pipeline was 0.58 s. CONCLUSION: A fully automated grading system was developed to evaluate PEEs. The grading results may serve as a reference for ophthalmologists in clinical trials and residency training procedures.

A Fully Automated Segmentation and Morphometric Parameter Estimation System for Assessing Corneal Endothelial Cell Images.

PURPOSE: To develop a fully automated segmentation and morphometric parameter estimation system for assessing corneal endothelial cells from in vivo confocal microscopy images. DESIGN: Artificial intelligence (neural network) study. METHODS: First, a fully automated deep learning system for assessing corneal endothelial cells was developed using the development set (from 99 subjects). Second, 184 images (from 97 subjects) were used to construct the testing set to evaluate the clinical validity and usefulness of the automated segmentation and morphometric system. Third, the automatically calculated endothelial cell density (ECD) values, Topcon's cell density, and manually calculated ECD were compared. RESULTS: After slit lamp examination, 88 healthy subjects, 2 Fuchs endothelial dystrophy patients, and 7 corneal endotheliitis patients were identified among the 97 subjects in the testing set. The automatedly estimated morphometric parameters for the testing set were an average number of 234 cells, an ECD of 2592 cells/mm2, a coefficient of variation in the cell area of 32.14%, and a percentage of hexagonal cells of 54.16%. Pearson's correlation coefficient between the automated ECD and Topcon's cell density and between the manually calculated ECD and Topcon's cell density was 0.932 (P < .01) and 0.818 (P < .01), respectively. The Bland-Altman plot of Topcon's cell density and the automated ECD yielded 95% limits of agreement between 271.94 and -572.46 (concordance correlation coefficient = 0.9). CONCLUSIONS: A fully automated method for segmenting corneal endothelial cells and estimating morphometric parameters using in vivo confocal microscopy images is more efficient and accurate for assessing the normal corneal endothelium.

A short-term study of corneal collagen cross-linking with hypo-osmolar riboflavin solution in keratoconic corneas.

AIM: To report the 3mo outcomes of collagen cross-linking (CXL) with a hypo-osmolar riboflavin in thin corneas with the thinnest thickness less than 400 µm without epithelium. METHODS: Eight eyes in 6 patients with age 26.2±4.8y were included in the study. All patients underwent CXL using a hypo-osmolar riboflavin solution after its de-epithelization. Best corrected visual acuity, manifest refraction, the thinnest corneal thickness, and endothelial cell density were evaluated before and 3mo after the procedure. RESULTS: The mean thinnest thickness of the cornea was 408.5±29.0 µm before treatment and reduced to 369.8±24.8 µm after the removal of epithelium. With the application of the hypo-osmolar riboflavin solution, the thickness increased to 445.0±26.5 µm before CXL and recover to 412.5±22.7 µm at 3mo after treatment, P=0.659). Before surgery, the mean K-value of the apex of the keratoconus corneas was 57.6±4.0 diopters, and slightly decreased (54.7±4.9 diopters) after surgery (P=0.085). Mean best-corrected visual acuity was 0.55±0.23 logarithm of the minimal angle of resolution, and increased to 0.53±0.26 logarithm after surgery (P=0.879). The endothelial cell density was 2706.4±201.6 cells/mm(2) before treatment, and slightly decreased (2641.2±218.2 cells/mm(2)) at last fellow up (P=0.002). CONCLUSION: Corneal collagen cross-linking with a hypo-osmolar riboflavin in thin corneas seems to be a promising treatment. Further study should be done to evaluate the safety and efficiency of CXL in thin corneas for the long-term.

[Experimental research of small-incision Descemet's stripping endothelial keratoplasty].

OBJECTIVE: To investigate the surgical procedure, clinical efficacy, complications, density of endothelial cells and histological changes after Descemet's stripping endothelial keratoplasty (DSEK) surgery. METHODS: It was a experimental study. Twenty four New Zealand rabbits were divided into 3 groups, 8 rabbits per group. Donor grafts were dissected from 16 New Zealand rabbit eyes. Group A was experimental group, a 5 mm limbal tunnel incision was made. Descemet's membrane was striped off at 10 mm diameter, then the same diameter donor cornea (including Descemet's membrane and endothelium with a little of posterior stroma) was inserted into the recipient's anterior chamber. Air was injected into the anterior chamber to press the graft up against the recipient cornea. Group B was the control group, only striped the Descemet's membrane at the recipient cornea. Group C was the experiment control group, the procedure was similar to the group A, but the donor graft was without endothelial cells. RESULTS: All corneas of group A were transparent, and the mean density of the endothelial cells was (2195 +/- 77)/mm2 (t = 12.455, P < 0.001). Endothelial grafts attached to the recipients well and no scar formation between them under histological observation. The corneas were severe edema in groups B and C one month after surgery. CONCLUSIONS: DSEK is a safe surgery, can be recovered rapidly with little damages, and without interface scar formation after surgery. DSEK may be the first choice for the treatment of bullous keratopathy.

[Isolation and purification of eccrine sweat glands in human skin].

OBJECTIVE: To investigate the method of isolation and purification of epithelial cells of human eccrine sweat gland in vitro. METHODS: Through digesting human skin with collagenase type II, cells of human eccrine sweat gland were isolated. Highly purified gland cells were obtained through transferring into the conditioned medium with a micropipette for at least three times under an inverted microscope. Primary culture was started immediately after purification. Cells could be further purified by enzyme-digestion to eradicate the fibroblasts. RESULTS: Collagenase type II could digest dermal collagen with little damage to gland cells. Isolated cells from human sweat glands were adherent to the wall of culture flask, and they grew well in cultures. The problem of contamination by tissue debris and other cells such as fibroblast could be overcome. CONCLUSION: Isolation and purification of human sweat gland cells in vitro are still facing tough problems. Gland cells are successful to isolate and cultivate without contamination.

[Culture and identification of human skin fibroblasts].

OBJECTIVE: To explore the method of isolation, cultivation, and identification of human skin fibroblasts in vitro. METHODS: By digesting human skin with collagenase type II to isolate human eccrine sweat glands. The fibroblasts grew along with the growth of eccrine sweat gland cells,and they were separated by digesting with 0.25% trypsin and 0.02% ethylenediaminetetraacetic acid (EDTA). Dulbecco's modified Eagle's medium (DMEM) was the basic culture medium, being supplemented with fetal bovine serum (10%), penicillin (100 kU/L), and streptomycin(100 mg/L) Fibroblasts were incubated at 37 centigrade in a humidified atmosphere of 5% CO2 and 95% air in the incubator. Cellular morphologies were observed by inverted phase contrast microscopy and hematoxylin-eosin staining, and the cultured cells were identified by vimentin immunostaining and chromosome analysis. RESULTS: The isolated fibroblasts could grow and proliferate in vitro, and immunostaining of vimentin was positive in cultured fibroblasts and the number of chromosome was 46. CONCLUSION: Acquired human skin fibroblasts can be cultured in stable condition in vitro, and sufficient and reliable target cells can be obtained for the study of the mechanisms of wound healing at molecular level.