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In this study, the severity of eye pain (EP) and associated objective findings were evaluated in aqueous-deficient dry eye (ADDE) patients using PainVision®, a quantitative pain-measuring device. This study involved 53 eyes of 53 ADDE patients (6 males and 47 females; mean age: 64.4 ± 13.4 [mean ± SD] years). Of those, 18 eyes of 18 patients underwent punctal occlusion, and EP and objective findings in those patients were evaluated before and after treatment. In all patients, the severity of EP as measured by PainVision® was assessed using the Pain Degree (PD). The median PD for the 53 patients was 30.6 µA/µA (interquartile range, 16.9–93.2), and the nasal and central corneal staining score and the upper lid-wiper epitheliopathy score were significantly correlated with PD (R = 0.33, 0.33, and 0.28, respectively) (all: p < 0.05). Using the least squares method, the central corneal staining score most significantly affected PD. In the 18 cases that underwent punctal occlusion, PD was significantly reduced (median PD: 24.8 to 7.1 µA/µA; p < 0.0001). Using the least squares method, the central corneal staining score and tear meniscus radius were significantly more influential as factors contributing to PD before and after treatment, and central corneal epithelial damage was the factor most associated with ADDE-related EP.

Abstract Background The genetic architecture underlying central cornea thickness (CCT) is far from understood. Most of the CCT-associated variants are located in the non-coding regions, raising the difficulty of following functional characterizations. Thus, integrative functional analyses on CCT-associated loci might benefit in overcoming these issues by prioritizing the hub genes that are located in the center of CCT genetic network. Methods Integrative analyses including functional annotations, enrichment analysis, and protein-protein interaction analyses were performed on all reported CCT GWAS lead SNPs, together with their proxy variants. Functional annotations were conducted by CADD, GWAVA, and Eigen. Enrichment analyses for CCT-associated genes were performed using ToppGene suite. Protein-protein interaction network and gene co-expression analyses were performed by GeneMANIA. Results Functional annotations prioritized eight genes (ADAMSTS6, ARID5B, FOXO1, AKAP13, COL4A3, COL8A2, TBL1XR1, and KCMB2) harboring SNPs with strong evidence of regulatory potential. It was also shown that CCT-associated genes were significantly enriched in collagen-related pathways and the phenotype of keratoconus, and some of them were found to be involved in one interaction network. Conclusion This study revealed the hub genes that were located in the center of CCT genetic network and provided a new insight into the genetic regulation underlying CCT GWAS findings.

"AIM: To report the outcomes of patients undergoing anterior segment optical coherence tomography-guided transepithelial phototherapeutic keratectomy (ASOCT T-PTK) for central corneal scarring after pterygium excision. METHODS: The charts of 11 eyes of 10 patients that underwent ASOCT T-PTK following excision of visual axis-involving pterygia were retrospectively reviewed from a single private practice institution. The visual outcomes and corneal topographic findings were evaluated 4±1mo after pterygium excision and 6±2mo after transepithelial phototherapeutic keratectomy (T-PTK). RESULTS: All 11 eyes tolerated both the pterygium excision and T-PTK procedure well without any significant intraoperative or postoperative complications. Uncorrected distance visual acuity (UDVA) and manifest refraction corrected distance visual acuity (CDVA) improved after pterygium excision (P=0.03 and P=0.05, respectively). The UDVA and CDVA improved further after T-PTK (P=0.004 and P=0.002, respectively). The topographic surface asymmetry index, topographic surface regularity index, and topographic projected visual acuity significantly improved after T-PTK (P=0.0092, P=0.0022, and P=0.0002, respectively). None of the subjects lost any lines of CDVA, developed recurrence of pterygia or required keratoplasty during the postoperative period. CONCLUSION: ASOCT T-PTK can provide excellent visual and anatomic outcomes in patients with central corneal scarring after excision of visual axis-involving pterygia."

The Purpose of present study was to investigate the effect of riboflavin/ultraviolet-A-induced collagen cross-linking (CXL) on central cornea, limbus and intraocular pressure (IOP). This was an animal experimental study. The right corneas of 10 rabbits were ultraviolet-A irradiated (3 mW/cm2 for 30 minutes) after de-epithelialization and instillation of 0.1% riboflavin / 20% Dextran drops. Left corneas served as controls. Samples were examined histologically one month postoperatively. Before and after treatment, IOP measurements were recorded bilaterally. At central cornea of eyes underwent CXL keratocyte repopulation, normal arrangement of collagen fibres and a statistically significant change in fibres diameter were detected, compared to controls. At limbus area, there were not any significant histological differences after CXL. There was no statistically significant difference between pre- and postoperative IOP in all eyes.

Christine W Sindt1, Trudy K Grout1, D Brice Critser1, Jami R Kern2, David L Meadows21University of Iowa Hospitals and Clinics, Iowa City, IA; 2Alcon Research Ltd, Fort Worth, TX, USABackground: The purpose of this study was to assess whether differences in central corneal dendritic immune cell densities associated with combinations of soft contact lenses and lens care solutions could be detected by in vivo confocal microscopy.Methods: Participants were adults naïve to contact lens wear (n = 10) or who wore soft contact lenses habitually on a daily-wear schedule (n = 38) or on a study-assigned schedule for 30 days with daily disposable silicone hydrogel lenses (n = 15). Central corneas were scanned using an in vivo confocal microscope. Cell densities were compared among groups by demographic parameters, lens materials, and lens care solutions (polyhexamethylene biguanide [PHMB], polyquaternium-1 and myristamidopropyl dimethylamine [PQ/MAPD], peroxide, or blister pack solution [for daily disposable lenses]).Results: Among lens wearers, no associations were observed between immune cell densities and age, gender, or years of lens-wearing experience. Mean cell density was significantly lower (P < 0.01) in nonwearers (29 ± 23 cells/mm2, n = 10) than in lens wearers (64 ± 71 cells/mm2, n = 53). Mean cell density was lower (P = 0.21) with traditional polymer lenses (47 ± 44 cells/mm2, n = 12) than with silicone hydrogel lenses (69 ± 77 cells/mm2, n = 41). Lowest to highest mean density of immune cells among lens wearers was as follows: PQ/MAPD solution (49 ± 28 cells/mm2), blister pack solution (63 ± 81 cells/mm2), PHMB solution (66 ± 44 cells/mm2), and peroxide solution (85 ± 112 cells/mm2).Conclusion: In this pilot study, in vivo confocal microscopy was useful for detecting an elevated immune response associated with soft contact lenses, and for identifying lens-related and solution-related immune responses that merit further research.Keywords: Clear Care, in vivo confocal microscopy, Langerhans, Opti-Free Replenish, ReNu Multi-Plus

OBJETIVO: Analisar a possível variação da pressão intra-ocular, obtida por diferentes tonômetros, com a espessura central da córnea. MÉTODOS: Após a medida da pressão intra-ocular com o ICare, instilou-se uma gota de colírio anestésico e fez-se a medida da espessura da córnea e, também, a medida da pressão intra-ocular com o tonômetro de contorno dinâmico de Pascal. Em seguida, instilou-se uma gota de colírio de fluoresceína e mediu-se a pressão intra-ocular o tonômetro de aplanação de Goldmann. RESULTADOS: 138 olhos de 71 pacientes foram examinados e divididos em 3 grupos de acordo com a espessura central da córnea. A análise da pressão intra-ocular mostrou valores concordantes quando se utilizou o ICare e o tonômetro de contorno dinâmico de Pascal, com média de diferença de -0,2. A pressão intra-ocular medida com o tonômetro de contorno dinâmico de Pascal apresentou valores maiores que os obtidos com o tonômetro de aplanação de Goldmann, com média de diferença de -3,1. Uma diferença estatisticamente significante foi obtida nas medidas com o ICare e tonômetro de aplanação de Goldmann. CONCLUSÃO: Existe uma diferença estatisticamente significante entre os valores da PIO obtidos com ICare, tonômetro de contorno dinâmico de Pascal e tonômetro de aplanação de Goldmann, quando relacionados com a espessura central da córnea.PURPOSE: Could the central corneal thickness (CCT) change the intraocular pressure (IOP) measured by ICARE (IC) GOLDMANN APPLANATION TONOMETER (GAT) and PASCAL DYNAMIC COUNTOUR TONOMETER (PDCT). METHODS: Before using the anesthesia we have measured the IOP with IC tonometer. After that we have used topical anesthesia to obtain the CCT using an ultrasound pachymeter (Mentor Co.) and the IOP measured by PCDT followed by a drop of fluorescein to measured IOP with GAT. RESULTS: 138 eyes of 71 patients were analyzed. Patients were divided into 3 groups according to CCT. Best correlation was observed with IC and PDCT, showing a mean average difference of -0.2. The intraocular pressure data obtained from PDCT showed higher values when compared with GAT, with a mean average difference of -3.1. There are also a statistical significant difference with the IOP measurements with IC and GAT. CONCLUSION: There are a significant difference in IOP measurements obtained by IC, GAT and PCDT when compared with CCT.

Purpose: To characterize and correlate guttata severity, Descemet's membrane thickness (DMT), central cornea thickness (CCT) in corneas with guttae using specular microscopy and spectral-domain optical coherence tomography (SD-OCT) and test the Doheny Image Reading Center (DIRC) specular microscopy-based corneal guttata severity scale. Methods: Forty-nine eyes of 49 patients with guttata and 36 eyes of age-matched of 36 normal controls were enrolled in the study. Three images of the central cornea and four of the peripheral cornea (inferior, superior, nasal and temporal) of each eye were taken using the Konan NSP-9900 specular microscope. A volume scan of the central cornea cross-section was collected on each eye using the Heidelberg Spectralis SD-OCT. The density of endothelial guttata based on specular images was graded on a 0–4 scale, and the Descemet's membrane thickness (DMT) and central corneal thickness (CCT) were manually measured by two trained graders. Results: The DIRC corneal guttata severity scale showed good reproducibility of all corneal endothelial images (weighted Kappa = 0.87). Mean DMT was 16.1 ± 2.4 µm in controls and 25.5 ± 10.9 µm in corneas with guttata (P < 0.001). Mean CCT was 552 ± 26 µm in controls and 603 ± 55 µm in corneas with guttata (P < 0.001). Guttata severity was significantly correlated with both DMT (r = 0.743, P < 0.001) and CCT (r = 0.569, P < 0.001). Age was moderately correlated with DMT (r = 0.472, P = 0.003) and mildly correlated with guttata severity (r = 0.285, P = 0.031), but was not correlated with CCT (r = 0.058, P = 0.681). Guttatta grade 3 corneas displayed an increase in DMT and guttata grade 4 was associated with a significant increase in CCT. Conclusions: The DMT and CCT are increased in corneas with guttata. The higher density of guttae is correlated with increased thickness. Specular microscopy combined with SD-OCT can be used as a good approach to assess the severity of FECD. [ABSTRACT FROM AUTHOR]

Purpose: To determine whether excimer laser ablation of guttae is a viable strategy for removal of diseased tissue in Fuchs' endothelial corneal dystrophy (FECD) on excised human Descemet membranes and whether an excimer laser‐created wound on healthy human corneas ex vivo is recolonized with corneal endothelial cells. Methods: Descemet membranes of FECD patients and corneal endothelium of normal human corneas were ablated ex vivo using an excimer laser licensed for glaucoma surgery. Specimens were kept in cell culture medium supplemented with 10 μm of rho‐kinase inhibitor ripasudil. Corneal endothelial cell regeneration was observed using light and electron scanning microscopy. Furthermore, the whole corneal samples were evaluated by haematoxylin/eosin staining and immunohistochemical analysis using antibodies against Na+/K+‐ATPase. Results: Guttae and corneal endothelium could be ablated with an excimer laser without total ultrastructural damage to the Descemet membrane or stroma. Nearly complete endothelial wound closure was accomplished after 26–38 days in treated corneas. Light and electron scanning microscopy suggested the establishment of a layer of flat endothelial cells. Additionally, Na+/K+‐ATPase expression could only be observed on the inner side of the Descemet membrane. Conclusion: Our proof of concept study demonstrated that excimer lasers can be used to ablate diseased tissue from excised FECD Descemet membranes ex vivo. Additionally, corneal endothelial cells recolonize a previously ablated endothelial area in healthy human corneas ex vivo under treatment with ripasudil. Thus, our results are the first experimental basis to further investigate the feasibility of an excimer laser ablation as a graftless FECD treatment option. [ABSTRACT FROM AUTHOR]

Purpose: We aimed to compare central corneal thickness (CCT) measurements in eyes with primary open-angle glaucoma (POAG) with optical biometry (Haag-Streit Lenstar LS 900 Optical Biometer,Switzerland) and ultrasonic pachymetry (USP) devices. Materials and Methods: We included 35 eyes of 35 patients with POAG in this prospective observational study. CCT was measured with the optic biometric pachymetry and an USP device (Pac-Scan 300p, Sonomed Escalon, NY, USA). While the fi rst observer conducted the measurement with both the optic biometric pachymetry and USP devices, the second observer only used the optic biometric pachymetry device. Spearman correlation analysis was used in the correlation analysis. Results: Central corneal thickness with the optic biometric pachymetry was 526.6±39.6 µm for the first observer and 527.7±40.6 µm for the second observer. The central corneal thickness was 541.9±43.6 µm with USP. Statistically significant lower measurements were found with the optic biometric pachymetry device than with USP (p<0.001). A statistically significant and strong correlation was present between the observers' measurements of the central cornea thickness with the optic biometric pachymetry (r=0.995, p<0.001). A statistically significant and strong correlation was also present between the central corneal thickness measurements of the first observer using the two devices (r=0.943, p<0.001). Conclusion: Optic biometric pachymetry provides lower central corneal thickness measurements than USP in primary open-angle glaucoma. Although there is a strong correlation between the two devices, this difference may be important in intraocular pressure measurements. [ABSTRACT FROM AUTHOR]

In this study, the severity of eye pain (EP) and associated objective findings were evaluated in aqueous-deficient dry eye (ADDE) patients using PainVision®, a quantitative pain-measuring device. This study involved 53 eyes of 53 ADDE patients (6 males and 47 females; mean age: 64.4 ± 13.4 [mean ± SD] years). Of those, 18 eyes of 18 patients underwent punctal occlusion, and EP and objective findings in those patients were evaluated before and after treatment. In all patients, the severity of EP as measured by PainVision® was assessed using the Pain Degree (PD). The median PD for the 53 patients was 30.6 µA/µA (interquartile range, 16.9–93.2), and the nasal and central corneal staining score and the upper lid-wiper epitheliopathy score were significantly correlated with PD (R = 0.33, 0.33, and 0.28, respectively) (all: p < 0.05). Using the least squares method, the central corneal staining score most significantly affected PD. In the 18 cases that underwent punctal occlusion, PD was significantly reduced (median PD: 24.8 to 7.1 µA/µA; p < 0.0001). Using the least squares method, the central corneal staining score and tear meniscus radius were significantly more influential as factors contributing to PD before and after treatment, and central corneal epithelial damage was the factor most associated with ADDE-related EP. [ABSTRACT FROM AUTHOR]

Objective: To determine the accuracy of the Reichert® Tono‐Vera® Vet rebound tonometer for canine intraocular pressure (IOP) measurement. Animals Studied: Five normal canine ex vivo globes. Procedures: The anterior chambers of five freshly enucleated normal canine eyes were cannulated and connected to a reservoir of Plasma‐Lyte A and a manometer. Starting at a manometric IOP of 5 mmHg, the pressure was progressively increased to 80 mmHg by raising the reservoir. Triplicate IOP measurements were taken with the Tono‐Vera® Vet from the central cornea using the dog setting and compared to the manometric pressure by linear regression analysis and Bland–Altman plots. Results: There was a strong positive linear regression trend when comparing central corneal Tono‐Vera® Vet IOPs to manometric pressures (r2 =.99) with solid agreement between the two methods. Compared to manometric IOPs, the Tono‐Vera® Vet underestimated IOPs at higher pressures ≥70 mmHg. Conclusions: Measurement of IOPs from the central cornea with the Tono‐Vera® Vet provided accurate results over a large range in normal canine globes compared to direct manometry. The mild to moderate underestimation of IOPs at high pressures was not considered clinically relevant. [ABSTRACT FROM AUTHOR]

Abstract Background Optical coherence tomography angiography (OCTA) is a novel technology that provides a noninvasive, dye-less method to visualize the blood vessels of the retina. In the present study, we investigate macular microvascular density and the correlation of ocular and demographic factors using OCTA in Posner-Schlossman syndrome (PSS) patients. Methods This is a prospective observational study. All PSS patients and age- and sex-matched healthy subjects underwent complete ophthalmologic examination, and RE, BCVA, IOP, CCT, AL, CMT, GCIPI, RNFL, C/D ratio were recorded. The whole-image vessel density (wiVD) and whole-image perfusion density (wiPD), three-circle (1 mm central ring, 3 mm inner ring, 6 mm outer ring), and four-quadrant segmental VD and PD were calculated. Results Seventeen PSS patients and 17 healthy subjects were enrolled in this study. The mean age was 42.65 ± 11.22 years in PSS patients and 42.71 ± 10.50 years in healthy controls. IOP, CCT, and C/D ratio were higher in PSS-attacked eyes, and BCVA, OPP and RNFL thickness was lower than those in the fellow eyes (p

Purpose: Our aim was to compare specular microscopy (SM) and a new corneal topographer with rotating Scheimpflug camera (Pentacam) for non-contact pachometry of the central cornea. The repeatability of Pentacam for topographic pachometry was also studied. Methods: Thirty-nine subjects were recruited and one eye was selected randomly for non-contact pachometry by SM and by Pentacam, in random order. The corneal thickness (CT) was monitored at 30-second intervals for 10 minutes. Baseline CT was defined as the average of all measurements taken over the 10 minutes. Subjects were required to return within one to two weeks for a second corneal evaluation by Pentacam. Comparisons were made on the central CT between the two devices and on the topographic CT from Pentacam between the two visits. Results: The spontaneous variation of central CT was similar for the two instruments. Central CT varied within ±2.3 µm during the 10 minutes. The 95% limits of agreement between SM and Pentacam were within ±15 µm for the central CT. The spontaneous variation of peripheral CT was within ±3.1 µm. There was no significant difference (p > 0.05) between the two visits on CT at different regions. Further analysis found that with Pentacam three measurements should be taken to obtain topographic CT measurement of one per cent precision. Conclusion: Non-contact specular microscopy and Pentacam have good agreement for central CT measurement. Topographic pachometry from Pentacam requires three repeated measurements for one per cent precision. [ABSTRACT FROM AUTHOR]

Abstract: The side population (SP) phenotype is shared by stem cells in various tissues and species. Here we demonstrate SP cells with Hoechst dye efflux were surprisingly collected from the epithelia of both the rat limbus and central cornea, unlike in human and rabbit eyes. Our results show that rat limbal SP cells have a significantly higher expression of the stem cell markers ABCG2, nestin, and notch 1, compared to central corneal SP cells. Immunohistochemistry also revealed that ABCG2 and the epithelial stem/progenitor cell marker p63 were expressed only in basal limbal epithelial cells. These results demonstrate that ABCG2 expression is closely linked to the stem cell phenotype of SP cells. [Copyright &y& Elsevier]

Introduction: The aim of this work is to evaluate the effect of mesenchymal stem cell transplantation (MSCT) and cultivated limbal epithelial transplantation (CLET) therapies on the limbus of patients suffering from limbal stem cell deficiency (LSCD). Methods: A sub-analysis of a phase I–II randomized, controlled, and double-masked clinical trial was performed to assess the changes in the anatomical structures of the limbus. In vivo confocal microscopy (IVCM) analysis was carried out in LSCD eyes before and 12 months after allogeneic MSCT or CLET. Epithelial phenotype of the central cornea, as well as the presence of transition zones and palisades of Vogt in the limbus, were assessed using Wilcoxon test. Results: Twenty-three LSCD (14 MSCT and nine CLET) eyes were included. The epithelial phenotype of the central cornea improved significantly (p < 0.001) from 15 (eight MSCT, seven CLET) and eight (six MSCT, two CLET) LSCD eyes showing conjunctival and mixed phenotypes, respectively, to eight (five MSCT, three CLET), five (two MSCT, three CLET), and ten (seven MSCT, three CLET) eyes showing conjunctival, mixed, and corneal phenotypes, respectively. Transition areas and palisades of Vogt were observed in at least one quadrant in nine (five MSCT, four CLET) and 16 (nine MSCT, seven CLET), and in four (two MSCT, two CLET) and six (three MSCT, three CLET) LSCD eyes before and after surgery, respectively. Changes in the transition zones and palisades were solely significant (p = 0.046) for the nasal and inferior quadrants, respectively. Conclusions: MSCT and CLET improved the central corneal epithelial phenotype despite only minor changes in the anatomical structures of the limbus, as detected by IVCM technology. Trial Registration: ClinicalTrials.gov identifier, NCT01562002. [ABSTRACT FROM AUTHOR]

Purpose: To measure variation in corneal dendritic cell density, and percentage of mature to total dendritic cells, in healthy individuals during the sleep/wake cycle. Methods: Using in vivo confocal microscopy, images of the subbasal nerve plexus were captured from 19 healthy, noncontact lens wearing participants. The central cornea and inferior whorl were imaged three times (midday, before sleep, upon awakening). Dendritic cell counts from the images were categorized according to perceived maturity (immature vs mature). Dendritic cell density and percentage of mature to total cells were compared between time points. Result: The median and interquartile range (IQR) of total dendritic cell density in the central cornea was 32.0 (7.0–131.3) cells/mm2 at midday, 37.1 (8.2–103.9) cells/mm2 before sleep, and 19.5 (7.0–83.2) cells/mm2 on awakening. Corresponding values for immature cells were 28.1 (5.8–112.5) cells/mm2, 22.3 (7.4–84.0) cells/mm2 and 18.0 (2.9–64.8) cells/mm2, and for mature cells, 3.1 (0.0–6.6) cells/mm2, 2.0 (0.8–16.8) cells/mm2, and 1.6 (0.2–8.2) cells/mm2. At the inferior whorl, total dendritic cell density was 38.5 (18.4–84.5) cells/mm2, 34.4 (9.4–82.3) cell/mm2, and 32.3 (15.2–96.1) cells/mm2. Immature cell density was 32.8 (18.4–80.9) cells/mm2, 34.4 (8.6–81.0) cells/mm2, and 32.3 (12.6–78.5) cells/mm2. Mature cell density was 1.6 (0.0–6.3) cells/mm2, 1.6 (0.0–3.1) cells/mm2, and 1.8 (0.0–6.3) cells/mm2. There was no significant difference between time points for total cell density (p > 0.05), but the percentage of mature cells upon awakening was significantly greater, compared to midday, at the central cornea (p = 0.02). Conclusion: In healthy individuals, overall corneal dendritic cell density is reasonably constant during the sleep/wake cycle, but the relative number of mature cells tends to increase overnight. [ABSTRACT FROM AUTHOR]

Purpose : To report the in-vivo confocal microscopic findings of dendritiform cells in the central corneal epithelial layer in a case of mixed bacterial keratitis associated with severe immunologic reaction. Design : Observational case report. Methods : A 25-year-old male suffered from contact lens-related mixed bacterial keratitis with a dense eccentric immune ring. In-vivo confocal microscopy was performed to study the different layers of the central and peripheral cornea in the lesion and the fellow eye. Results : Several dendritiform cells were found in the basal and superficial epithelial layers of the central cornea in the lesion eye, which was also the area of the dense immune ring formation. No such cells could be identified in the fellow eye or the unaffected area of the lesion eye. Conclusion : Corneal dendritiform cells, possibly dendritic or Langerhans cells, can be identified in severe corneal immunologic conditions using in-vivo confocal microscopy. The role of these cells in ocular immunity is interesting and needs further clarification. [ABSTRACT FROM AUTHOR]

Background: Prostaglandin analogs (PGAs) are first-line antiglaucoma agents that appear to either decrease or increase central cornea thickness (CCT), creating controversy regarding the benefits of PGAs in treating CCT. Purpose: We performed the first meta-analysis of observational studies to evaluate the effects of PGAs on CCT in patients with glaucoma or ocular hypertension (OHT). Methods: This systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement. A literature search was performed of the PubMed, Embase, Cochrane Library, System for Information on Grey Literature in Europe (Open Grey), and ClinicalTrials.gov databases and the references of retrieved studies. Only observational studies were included in the meta-analysis. The final CCT of patients and 95% confidence interval (CI) of each study were extracted. Study quality was assessed using the Newcastle-Ottawa Scale (NOS) and the Agency for Healthcare Research and Quality (AHRQ). A fixed-effects model was used to calculate the weighted mean difference (WMD) and 95% CI. Subgroup analyses based on several stratified factors such as public bias (Begg's test) and sensitivity analyses were performed. Results: Five cohort, 5 case-control, and three cross-sectional studies including 2,722 subjects were included. The pooled effect of all thirteen studies showed that PGAs reduced the CCT of patients with glaucoma or OHT slightly but significantly (WMD = −9.37; 95% CI [−12.18, −6.57]; p = 0.00; I2 = 45.5%). Significant effects were also observed in all three study designs: cohort (WMD = −5.17; 95% CI [−9.52, −0.82]), case-control (WMD = -15.31; 95% CI [−22.66, −7.97]), and cross-sectional (WMD = −8.65; 95% CI [−17.30, −0.01]). In addition, subgroup analysis of exposure time showed the effect of PGAs to be more obvious in the first (WMD = −5.81; 95% CI [−9.49, −2.14]) and second (WMD = −13.73; 95% CI [−20.19, −7.28]) years. Conclusions: The pooled effects of previously reported studies suggest that PGA use can reduce the CCT of patients with glaucoma or OHT slightly but significantly, with this effect more pronounced in the first 2 years. These findings suggest that clinicians must closely monitor changes in CCT in the first 2 years of PGA use to identify cases of intraocular pressure misestimation and the efficacy of PGAs. [ABSTRACT FROM AUTHOR]

Background: This study was designed to measure changes in anterior chamber depth (ACD), central cornea thickness (CCT), and axial length (AL) after scleral buckle (SB) surgery or pars plana vitrectomy (PPV) for the repair of rhegmatogenous retinal detachment (RD).Methods: We prospectively reviewed the records of 245 eyes of 245 patients scheduled to undergo SB surgery and 238 eyes of 238 patients scheduled to undergo PPV. ACD, CCT, and AL were measured by spectral-domain optical coherence tomography (SD-OCT) and biometry, before surgery as well as 6 and 12 months postoperatively.Results: For both SB and PPV surgeries, ACD was observed to decrease significantly postoperatively, with this trend continuing throughout the follow-up period (p < 0.005). CCT showed no significant difference after PPV or SB surgery. AL increased significantly after SB surgery but not PPV.Conclusion: Our results show that SB surgery altered the shape of the eye by changing both ACD and AL. PPV resulted in altered ACD. These findings should elucidate the changes to be expected after SB and PPV surgeries. [ABSTRACT FROM AUTHOR]

Purpose: To report a new severity grading system for Fuchs endothelial corneal dystrophy (FECD) using anterior segment optical coherence tomography (AS‐OCT). Methods: This observational case series included 75 eyes of 43 patients with FECD and 33 eyes of 33 healthy subjects. Pachymetry and posterior elevation maps were used to determine the AS‐OCT‐based grading scores. FECD severity was graded from 0–3 as follows: 0, normal; 1, guttae only; 2, stromal oedema; and 3, epithelial and stromal oedema. We further investigated the central corneal thickness (CCT), thinnest corneal thickness (TCT), anterior and posterior best‐fit spheres (BFS), and the distance between the central cornea and the thinnest point. Results: Thirty‐three eyes were graded as 0, four as 1, thirteen as 2, fourteen as 3, twenty‐nine as 4, eleven as 5 and four as 6 by the modified Krachmer grade. Thirty‐three, 41, 30 and 4 eyes were graded as 0, 1, 2 and 3, respectively, by the AS‐OCT‐based grading system. The inter‐observer agreement was 100% for the AS‐OCT‐based grading system. The CCT, TCT, posterior BFS, and distance between the central cornea and thinnest point were significantly different between AS‐OCT‐based grades (p = 0.0001, 0.0001, 0.0036 and 0.0001, respectively). Anterior BFS was not significantly different with the AS‐OCT‐based grades (p = 0.1184). Conclusion: We devised a new severity grading using only objective evaluation and quantitatively demonstrated corneal thickening, predominant flattening of the posterior corneal surface compared with the anterior surface, and displacement of the thinnest point away from the central cornea with FECD progression. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the variation and stability of the posterior cornea surface parameters (posterior cornea curvature [PCC], posterior cornea astigmatism [PCA], and posterior cornea elevation [PCE]) after femtosecond laser-assisted in situ keratomileusis (LASIK) in patients with myopia and myopic astigmatism over a period of 6 months or longer. Methods: This retrospective study comprised 284 right eyes. Patients aged 18 years or older with myopia up to -12.00 D and/or astigmatism up to -6.00 DC and who underwent femtosecond LASIK were recruited. Patients were divided into three subgroups: low myopia (-0.50 to -3.00 D), moderate myopia (>-3.00 to ≤-6.00 D), and high myopia (>-6.00 D), according to their pre-LASIK spherical equivalent (SE). The variables included for analysis were PCC (central 0–3.0 mm, pericentral 3.0–6.0 mm, and peripheral region 6.0–9.0 mm), PCE, PCA, internal anterior chamber depth, intraocular pressure, and central cornea thickness at the pre- and post-LASIK stages. Results: The central PCC remained unchanged across all three myopia subgroups at 1 month when compared to the pre-LASIK stage and remained stable at 6 months. The pericentral regions became flatter across all myopia subgroups at 1 month postsurgery (P < 0.001) and remained unchanged at 6 months. This trend was not seen in the peripheral cornea regions, which remained unchanged at 1 and 6 months post-LASIK when compared to pre-LASIK mean readings. There were minimal changes in post-LASIK posterior cornea astigmatism throughout follow-up. There was no incidence of post-LASIK surgery ectasia in this study population. Conclusion: Post-LASIK, the different cornea subregions behaved differently. Overall, the posterior cornea surface remained stable post-LASIK across all myopia subgroups throughout follow-up. [ABSTRACT FROM AUTHOR]

In recent years, different laboratories have provided evidence on the role of miRNAs in regulation of corneal epithelial metabolism, permeability and wound healing, as well as their alteration after surgery and in some ocular pathologies. We searched the available databases reporting miRNA expression in the human eye, looking for miRNAs highly expressed in central cornea, which could be crucial for maintenance of the epithelial phenotype. Using the rabbit RCE1(5T5) cell line as a model of corneal epithelial differentiation, we describe the participation of miR-141-3p as a possible negative regulator of the proliferative/migratory phenotype in corneal epithelial cells. The expression of miR-141-3p followed a time course similar to the differentiation-linked KRT3 cytokeratin, being delayed 24–48 hours relative to PAX6 expression; such result suggested that miR-141-3p only regulates the expression of terminal phenotype. Inhibition of miR-141-3p led to increased cell proliferation and motility, and induced the expression of molecular makers characteristic of an Epithelial Mesenchymal Transition (EMT). Comparison between the transcriptional profile of cells in which miR-141-3p was knocked down, and the transcriptomes from proliferative non-differentiated and differentiated stratified epithelia suggest that miR-141-3p is involved in the expression of terminal differentiation mediating the arrest of cell proliferation and inhibiting the EMT in highly motile early differentiating cells. [ABSTRACT FROM AUTHOR]

We have compared the biomechanical properties of human and porcine corneas using vibrational optical coherence tomography (VOCT). The elastic modulus of the cornea has been previously reported in the literature to vary from about several kPa to more than several GPa based on the results of different techniques. In addition, the formation of corneal cones near the central cornea in keratoconus has been observed in the clinic. Measurements of the resonant frequency and morphology of human and porcine corneas were used to evaluate the role of the limbus in corneal stabilization, the effect of Bowman's layer, and the effect of collagen content on the low-strain corneal biomechanics. The results of these studies indicate that limbus stability plays an important anatomic role in preventing folding, corneal slippage, and cone formation. Machine learning studies of both human and porcine corneas indicate that Bowman's membrane, like that of the collagen fibrils found in the anterior corneal stroma, contributes to the 110–120 Hz resonant frequency peak. Finite element and SOLIDWORKS models of normal and keratoconus corneas suggest that the deformation of the cornea is the highest at the central zone and is higher in keratoconus corneas compared to normal controls. VOCT results suggest that although collagen fibril slippage occurs first at the limbus, cone formation in keratoconus occurs centrally/paracentrally, where stress concentration and deformation due to intraocular forces are the highest. Cone formation occurs at the points of maximum curvature. Results of these studies indicate the elastic modulus of cornea fibrillar collagen dictates the corneal elastic modulus at low strains. These results suggest that tension in the cornea at the limbus results in deformation into the low modulus region of the J-shaped stress–strain curve, resulting in an in vivo strain of less than about 10%. We propose that tension in the cornea provides a baseline force that regulates corneal epithelial regeneration as well as corneal lamellae composition and matrix turnover. [ABSTRACT FROM AUTHOR]