Association between corneal endothelial cell densities and elevated cytokine levels in the aqueous humor

Expression of Matrix Metalloproteinase-3 in the Aqueous Humor of Patients with Posner-Schlossman Syndrome

PURPOSE

To explore the expression of matrix metalloproteinase-3 (MMP-3) in the aqueous humor of patients with Posner-Schlossman syndrome (PSS), and the association between MMP-3 and PSS.

METHODS

Peripheral blood and aqueous humor were routinely collected from 29 patients with PSS (PSS group) and 30 patients with age-related-cataract (ARC) (control group). The content of MMP-3 in serum and aqueous humor was measured by immunoturbidimetry. The correlation between MMP-3 and ophthalmic examination results were verified by Spearman's correlation analysis.

RESULTS

The MMP-3 level in the aqueous humor of the PSS group was (25.86 ± 13.4)ng/ml, significantly higher than that in the control group (3.9 ± 2.7)ng/ml(p < 0.001), while there was no significant difference in serum MMP-3 level between the two groups (p = 0.125). The endothelial cell density (ECD) in the aqueous humor of the PSS group was (2078 ± 440) cell/mm2, intraocular pressure (IOP) in the aqueous humor of the PSS group was (33 ± 12) mmHg. The correlation analysis of aqueous humor MMP-3 and various ophthalmic examination results showed that aqueous humor MMP-3 had a moderate correlation with IOP and the difference in ECD between the affected eye and the fellow eye.

CONCLUSIONS

MMP-3 level is elevated in the aqueous humor of PSS patients, and it may play an important role in the pathogenesis of PSS.

Donor Corneal Endothelial Cell Maturity and Its Impact on Graft Survival in Glaucoma Patients Undergoing Corneal Transplantation

PURPOSE

To examine corneal graft survival via corneal endothelial cell density (ECD) and corneal endothelial cell loss (ECL) at 5 years post-transplantation in the eyes of patients with and without a history of undergoing glaucoma surgery according to the maturity of the donor corneal endothelial cells.

DESIGN

Prospective cohort study.

METHODS

This prospective cohort study included 17 patients with glaucoma and 51 patients without glaucoma who underwent Descemet's stripping automated endothelial keratoplasty or penetrating keratoplasty at the Baptist Eye Institute, Kyoto, Japan, between October 2014 and October 2016. Human corneal endothelial cells were cultured from residual peripheral donor cornea tissue, and the maturity of the cells was evaluated by cell surface markers (ie, CD166+, CD44-/dull, CD24-, and CD105-) using fluorescence-activated cell sorting. Kaplan-Meier analysis or the chi-square test was used to assess the rate of successful corneal graft survival post-transplantation.

RESULTS

At 36 months postoperatively, the mean ECD and ECL in the glaucoma-bleb eyes were 1197 ± 352 cells/mm2 and 55.5% ± 13.9% in the high-maturity group and 853 ± 430 cells/mm2 and 67.7% ± 18.1% in the low-maturity group, respectively. Kaplan-Meier analysis revealed that at 5 years postoperatively, the overall rate of survival was 45%, that is, 100% in the high-maturity group and 25% in the low-maturity group (P < .05).

CONCLUSIONS

The findings in this prospective cohort study revealed that the use of donor corneal grafts containing mature-differentiated corneal endothelial cells could maintain the survival of the transplanted graft for a long-term period, even in patients with a history of undergoing glaucoma surgery.

Selective Upregulation of Interleukin 1 Receptor Antagonist and Interleukin-8 in Fuchs' Endothelial Corneal Dystrophy with Accompanying Cataract

(1) Background: Patients with Fuchs' endothelial corneal dystrophy (FECD) may have coexisting cataracts and, therefore, may require a cataract surgery, which poses challenges due to potential endothelial cell damage. FECD is a degenerative eye disease of unclear etiology, with inflammatory cytokines maybe playing an important role in its development and progression. The present study aimed to investigate the cytokine profile in the aqueous humor of FECD eyes with cataract. (2) Methods: Fifty-two patients were included in the study, 26 with FECD + cataract and 26 with cataract as a control group. Samples of the aqueous humor were analyzed for pro- and anti-inflammatory cytokines using a Bio-Plex 200 system. (3) Results: Interleukin 1 receptor antagonist (IL-1Ra) and interleukin IL-8 levels were significantly higher in the aqueous humor of FECD + cataract patients compared to the control/cataract group. Moreover, the levels of anti-inflammatory IL-10 showed a strong trend to be higher in the FECD + cataract group compared to the control group. In contrast, there were no statistically significant differences in IL-1β, IL-6, IL-4, IL-10, IL-13, IL-17A, and tumor necrosis factor TNF-α between the groups. (4) Conclusions: Presented research contributes to a better understanding of FECD pathogenesis. Elevated levels of IL-1Ra and IL-8 may serve as a defense mechanism in people with FECD and coexisting cataract.

Characterization of a Novel Mouse Model for Fuchs Endothelial Corneal Dystrophy

Purpose

Fuchs endothelial corneal dystrophy (FECD) is a progressive blinding disorder, characterized by increased corneal endothelial excrescences (guttae), corneal endothelial cell loss, and edema. These symptoms are hypothesized to be caused by changes in the extracellular matrix (ECM) and mitochondrial dysfunction in the corneal endothelium. Despite this clinical and biological relevance, a comprehensive animal model that recapitulates all the major disease characteristics is currently unavailable. In this study, we develop such a model to improve our understanding of the signaling pathways involved in the FECD progression and develop strategies for early intervention.

Method

To generate a comprehensive FECD model, we generated a double mutant mouse bearing tamoxifen-inducible knockdown of Slc4a11 and the Col8a2 (Q455K) mutation. We performed optical coherence tomography (OCT) and in vivo confocal microscopy using the Heidelberg Retinal Tomography 3 - Rostock Cornea module (HRT3-RCM) on the mice at 5 weeks of age before tamoxifen feeding to establish baseline values for corneal thickness, endothelial cell density, and test for the presence of guttae. We measured these parameters again post-tamoxifen treatment at 16 weeks of age. We collected corneas at 16 weeks to perform histopathology, immunofluorescence staining for tight junctions, adherens junctions, and oxidative stress. We evaluated endothelial pump function using a lactate assay.

Results

The double mutant tamoxifen-fed animals showed the presence of guttae, and displayed increased corneal thickness and decreased endothelial cell density. Endothelial cells showed altered morphology with disrupted adherens junctions and elevated reactive oxygen species (ROS). Finally, we found that stromal lactate concentrations were elevated in the double mutant mice, indicative of compromised endothelial pump function.

Conclusions

Overall, this mouse model recapitulates all the important phenotypic features associated with FECD.

Integrated Analysis of Transcriptome and Proteome of the Human Cornea and Aqueous Humor Reveal Novel Biomarkers for Corneal Endothelial Cell Dysfunction

Earlier studies have reported that elevated protein levels in the aqueous humor (AH) are associated with corneal endothelial cell dysfunction (CECD), but the details of the underlying mechanism as well as specific biomarkers for CECD remain elusive. In the present study, we aimed to identify protein markers in AH directly associated with changes to corneal endothelial cells (CECs), as AH can be easily obtained for analysis. We carried out an in-depth proteomic analysis of patient-derived AH as well as transcriptomic analysis of CECs from the same patients with bullous keratopathy (BK) resulting from CECD. We first determined differentially expressed genes (DEGs) and differentially expressed proteins (DEPs) from CECs and AH in CECD, respectively. By combining transcriptomic and proteomic analyses, 13 shared upregulated markers and 22 shared downregulated markers were observed between DEGs and DEPs. Among these 35 candidates from biomarker profiling, three upregulated markers were finally verified via data-independent acquisition (DIA) proteomic analysis using additional individual AH samples, namely metallopeptidase inhibitor 1 (TIMP1), Fc fragment of IgG binding protein (FCGBP), and angiopoietin-related protein 7 (ANGPTL7). Furthermore, we confirmed these AH biomarkers for CECD using individual immunoassay validation. Conclusively, our findings may provide valuable insights into the disease process and identify biofluid markers for the assessment of CEC function during BK development.

Role of corneal collagen cross-linking in bullous keratopathy: A systematic review

Corneal cross-linking (CXL), a corneal strengthening procedure, is known to alter anterior stroma swelling behavior and is one of the treatment modalities of bullous keratopathy (BK). There are multiple studies published on the role of CXL in the treatment of BK. These articles had heterogeneous study population, different protocols used, and variable conclusions. This systematic review aimed to determine the role of CXL in the treatment of BK. The primary outcomes considered were changes in central corneal thickness (CCT) after 1, 3, and 6 months of CXL. The secondary outcome measures were changes in visual acuity, corneal clarity, subjective symptoms, and complications after CXL. We included randomized control trials (RCTs), observational and interventional studies, and case series with reports of more than 10 cases in this review. In RCTs, the mean pre-CXL CCT (794.0 ± 178.5 μm) in the intervention group (n = 37), decreased at 1 month (750.9 ± 154.3 μm) followed by a subsequent increase, but this difference was not significant during the 6-month follow-up (P- value 0.28, 0.82, and 0.82 at 1, 3, and 6 months, respectively). In noncomparative clinical studies (n = 188), the mean pre-CXL CCT (794.0 ± 178.5 μm) decreased at 1 month (710.9 ± 127.2 μm, P < 0.0001). Seven of the 11 articles included in the review reported no significant improvement in vision with CXL. The initial improvement in corneal clarity and clinical symptoms was not sustained. Current evidence suggests that CXL has short-term efficacy in the treatment of BK. More RCTs with high-quality evidence are needed.

Proteomic characterization of aqueous humor in corneal endothelial decompensation after penetrating keratoplasty

Corneal endothelial decompensation (CED) is the major cause of the long-term graft failure, but the underlying mechanisms remain unclear. The purpose of this study was to characterize the proteomic profile in CED aqueous humor (AH) after penetrating keratoplasty (PKP). We collected AH samples (n = 6/group) from CED patients underwent PKP and cataract patients, respectively. The label-free quantitative proteomic analysis was performed to identify the differentially-expressed proteins (DEPs). The biological functions of DEPs were evaluated using Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genome (KEGG) analysis. The protein-protein interaction (PPI) network construction was employed to distinguish the hub proteins of DEPs, and the selected proteins were validated by parallel reaction monitoring (PRM). The human peripheral blood mononuclear cells (PBMCs) were adopted to investigate the effect of biglycan (BGN) on inflammatory response, and the subsequent outcomes of inflammation on human corneal endothelial cells (HCECs). A total of 174 DEPs were identified in CED AH of patients underwent PKP, including 102 up-regulated proteins and 72 down-regulated proteins. Bioinformatics analysis revealed the significant enrichment of cytokine-mediated signaling pathway and extracellular matrix (ECM) organization in the up-regulated proteins, as well as the alterations of cellular components, including the increase of collagen and complement component C1 complex, and reduction in extracellular exosomes. A hub protein cluster of 15 proteins was determined by Molecular Complex Detection (MCODE), including FN1, BGN, COMP, COL11A1, COLA3A1, and COL1A1. Moreover, BGN promoted pro-inflammatory cytokine (such as TNF-α, IL-1β and IL-6) production in PBMCs through NF-κB signaling pathway, which subsequently resulted in HCECs death. These findings provided a systemic protein profile of AH in CED patients after corneal transplantation, with the alterations implicated in cytokine-mediated signaling, ECM, complement system, and exsomes. The identified proteins and signaling pathways probably paved the novel insight into understanding the pathogenesis of the disease.

Identifying predictive factors for long-term visual recovery after corneal endothelial keratoplasty in Fuchs' dystrophy: Potential interaction between the corneal dysfunction and retinal status

Introduction

Descemet membrane endothelial keratoplasty (DMEK) is the main treatment for Fuchs' dystrophy (FECD). The outcomes are excellent, but the final visual recovery may vary from patient to patient with sometimes no obvious reason of such a spread.

Methods

We conducted a clinical prospective multicentric study to identify the predictive factors for the visual result 1 year after surgery. Eighty three patients (83 eyes) were included.

Results

Postoperative BCVA after 1 year was 0.20 ± 0.18 logMAR. Logistic regression revealed that good visual recovery correlated negatively with preoperative central macular thickness (p &lt; 0.001) and the need for rebubbling (p = 0.05), and positively with preoperative visual acuity (p = 0.009). Multivariate formula to predict the 1-year BCVA has been suggested.

Discussion

Preoperative retinal status seems to be the main predictive factor for long-term visual result after DMEK. Our predictive multivariate model could assist in better informing the patient about the prognosis of the surgery, and in adjusting the therapeutic strategy also, further highlighting the essential collaboration between both cornea and retina subspecialists.

Pathophysiology of Corneal Endothelial Cell Loss in Dry Eye Disease and Other Inflammatory Ocular Disorders

PURPOSE

Dry eye disease (DED) and other inflammatory ocular disorders have been reported to be associated with decreased corneal endothelial cell density (CECD), however the mechanism of underlying endothelial cell loss remains unknown.

METHODS

We conducted a comprehensive literature search of English-written publications on dry eye disease, corneal endothelial cell loss, Sjögren's syndrome, and Graft Vs Host Disease (GVHD), to review the effects of DED and other inflammatory ocular surface conditions on CECD.

RESULTS

A total of 78 studies were included in our study. Loss of corneal neurotrophic support, cytotoxic stress, and a heightened immune response, all of which may occur secondarily to a common causative agent such as inflammation, are major contributors to reduced CECD.

CONCLUSION

More studies are needed to determine how the interrelated pathways of altered corneal nerve function and upregulated expression of inflammatory activity influence corneal endothelial cell loss.

Role of Monocytes/Macrophages in the Etiology of Bullous Keratopathy After Argon Laser Iridotomy

Purpose

The etiologic mechanisms of bullous keratopathy (BK) after argon laser iridotomy (ALI) are still unknown. Therefore, we investigated potential mechanisms on BK after ALI.

Methods

Corneal endothelial surface obtained in penetrating keratoplasty for BK after ALI was observed and analyzed immunohistochemically. We investigated how various leukocytes react to cultured human corneal endothelial cells in an inflamed condition and monocytes/macrophages respond to the iris treated by an argon and YAG laser or pigmented and nonpigmented iris treated by an argon laser.

Results

We detected infiltration of CD68- and CD11b-positive monocytes/macrophages in the posterior surface of trephined corneas obtained during penetrating keratoplasty for BK after ALI in three of the seven eyes with ALI. In vitro, monocytes/macrophages, but not T cells, B cells, neutrophils, or pan-leukocytes, removed many cultured human corneal endothelial cells in the medium stimulated with proinflammatory cytokines. Human pigmented iris tissues treated by the argon laser, but not those treated by the YAG laser, attracted many monocytes/macrophages and formed large, round colonies. Human monocytes/macrophages formed large colonies on the argon laser–treated pigmented iris from C3H mice but not nonpigmented iris from albino BALB/c mice.

Conclusions

Our results suggest that monocytes/macrophages, argon laser, and pigmented iris are all involved in the pathogenesis of BK after LI.

Translational Relevance

Etiology in BK after ALI has not been clear, but our findings based on clinical and experimental findings give a critical clue to explain possible mechanisms on BK after ALI.

Outcomes and predictors of vitrectomy and silicone oil tamponade in retinal detachments complicated by proliferative vitreoretinopathy

AIM

To evaluate outcomes and determine factors influencing the outcomes of vitrectomy with silicone oil (SO) endotamponade for the management of rhegmatogenous retinal detachment (RRD) complicated by advanced proliferative vitreoretinopathy (PVR).

METHODS

This is a retrospective, interventional case series of eyes with PVR grade C associated RRD with or without prior surgery that underwent vitreoretinal surgery and SO tamponade. Eyes with a minimum follow-up of 6mo after SO extraction were included. Eyes were classified into three PVR subgroups according to severity and extension of proliferation. The influence of several preoperative, intraoperative and postoperative factors upon the functional and anatomical outcomes was assessed using multivariate logistic regression analysis.

RESULTS

A hundred and one eyes of 101 patients that met the inclusion criteria were studied. Seventy-five of 101 eyes (74.3%) had successful retinal reattachment after one operation. Increased aqueous cell and flare at the first week exam had a statistically significant association with redetachment, recurrent membrane proliferation and keratopathy. Visual acuity improvement was significantly associated with faint postoperative aqueous inflammation values, primary vitrectomy and PVR outside of the posterior pole.

CONCLUSION

Although encouraging anatomical and functional outcomes are achieved after vitrectomy and SO tamponade in eyes with RRD complicated by PVR, an increase in aqueous flare or cells at the first week follow-up is most likely to result in postoperative late complications. Primary vitrectomy, PVR associated with minimal posterior pole extension and absent to mild postoperative aqueous inflammation are associated with improved post-operative final visual acuity.

Severe Corneal Edema Increases ECL From Grafts After DSAEK-Corneal Edema and ECL After DSAEK

OBJECTIVES

To determine the relationship between the preoperative degree of corneal edema in the recipient and the endothelial cell density in grafts after Descemet stripping automated endothelial keratoplasty (DSAEK).

METHODS

This retrospective case series enrolled 111 eyes of 107 patients who underwent DSAEK. The preoperative and postoperative central corneal thickness (CCT) was measured by anterior-segment optical coherence tomography. Eyes were divided into three groups according to the preoperative recipient CCT: group A (mild edema): 550 μm

RESULTS

The recipient CCT (all groups combined) was 805.99±132.70 μm preoperatively and decreased to 656.31±105.02 μm at 1 month, decreased to 626.08±81.40 μm at 6 months, and remained stable between 12 (P=0.144) and 24 months (P=0.485) postoperatively. The mean ECL was 27.34±15.43%, 33.56±17.13%, 39.18±16.71%, and 45.87±14.27% at 1, 6, 12, and 24 months, respectively. The percentage of ECL in group C was higher than that in the other 2 groups through the 24-month follow-up. The difference in ECL between groups A and C was significant at 24 months (group A: 42.45±14.47%; group C: 52.49±10.65%; P=0.019).

CONCLUSIONS

The degree of corneal edema in the recipient was associated with implant ECL. Compared with mild and moderate corneal edema, the severe corneal edema may cause greater ECL after DSAEK.

Collapse

Key Words

• dsaek
• endothelial cell loss
• degree of corneal edema

Collapse

MESH Headings

• Corneal Diseases/etiology
• Corneal Diseases/surgery
• Corneal Edema/etiology
• Corneal Edema/surgery
• Descemet Stripping Endothelial Keratoplasty/adverse effects
• Descemet Stripping Endothelial Keratoplasty/methods
• Endothelial Cells
• Endothelium, Corneal/transplantation
• Humans
• Retrospective Studies

Collapse

Grants Collapse

Affiliation(s)

Shaofeng Gu Department of Ophthalmology (S.G., R.P., G.X., J.H.), Peking University Third Hospital, Beijing, China; and Beijing Key Laboratory of Restoration of Damaged Ocular Nerve (S.G., R.P., G.X., J.H.), Peking University Third Hospital, Beijing, China.
Rongmei Peng Department of Ophthalmology (S.G., R.P., G.X., J.H.), Peking University Third Hospital, Beijing, China; and Beijing Key Laboratory of Restoration of Damaged Ocular Nerve (S.G., R.P., G.X., J.H.), Peking University Third Hospital, Beijing, China.
Gege Xiao Department of Ophthalmology (S.G., R.P., G.X., J.H.), Peking University Third Hospital, Beijing, China; and Beijing Key Laboratory of Restoration of Damaged Ocular Nerve (S.G., R.P., G.X., J.H.), Peking University Third Hospital, Beijing, China.
Jing Hong Department of Ophthalmology (S.G., R.P., G.X., J.H.), Peking University Third Hospital, Beijing, China; and Beijing Key Laboratory of Restoration of Damaged Ocular Nerve (S.G., R.P., G.X., J.H.), Peking University Third Hospital, Beijing, China.

Collapse

Donor-Related Risk Factors for Graft Decompensation Following Descemet's Stripping Automated Endothelial Keratoplasty

Aims

To identify donor-related risk factors associated with graft endothelial failure and postoperative endothelial cell density (ECD) reduction after Descemet's stripping automated endothelial keratoplasty (DSAEK).

Methods

This was a single-center retrospective study conducted from July 2006-December 2016. We included 584 consecutive eyes (482 patients) that underwent DSAEK for the treatment of laser iridotomy-related bullous keratopathy (192 eyes), pseudophakic bullous keratopathy (137 eyes), regraft (96 eyes), Fuchs' endothelial corneal dystrophy (FECD; 59 eyes) and others (100 eyes). Twenty-three donor- and recipient-related risk factors potentially associated with graft failure and ECD reduction were assessed using Cox hazard models and linear mixed effect models.

Results

The median age of the patients was 73.5 years (male; 35.6%). After DSAEK, ECD decreased from 2,674 cells/mm2 (95% confidence interval [CI]; 2,646–2,701) to 1,132 (1,076–1,190) at 12 months and 904 (845–963) at 24 months (P &lt; 0.001). Fifty-five eyes (9.4%) had graft endothelial failure without rejection. This failure was associated with donor pseudophakic lens status (hazard ratio [HR]; 2.67, CI; 1.50–4.76, P = 0.001) and preoperative endothelial folds (HR; 2.82, CI; 1.20–6.62, P = 0.02). The incidence of graft endothelial failure in non-FECD patients was significantly higher among those receiving donor grafts with a pseudophakic lens status and preoperative presence of endothelial folds (P &lt; 0.001). Postoperative ECD loss was significantly greater in eyes with these risk factors compared to those without (P = 0.007).

Conclusions

Pseudophakic status and/or presence of preoperative endothelial folds are the significant donor risk factors for endothelial failure in non-FECD patients.

Association between aqueous humor cytokines and postoperative corneal endothelial cell loss after Descemet stripping automated endothelial keratoplasty

This study measured the intraoperative anterior aqueous humor concentrations of various cytokines during corneal endothelial transplantation and searched for relationships between these concentrations and postoperative corneal endothelial cell (CEC) depletion. We recruited 30 consecutive patients who underwent corneal endothelial transplantation with Descemet’s stripping automated endothelial keratoplasty (DSAEK) at Tohoku University Hospital between February 2014 and July 2017. During surgery, we obtained aqueous humor samples and later measured the concentrations of 27 cytokines with a Multiplex Bead Assay (Bio-Plex Pro). We counted CECs 1, 6 and 12 months after surgery, and used Spearman’s rank correlation coefficient to identify relationships between CEC depletion and the concentrations of detected cytokines. The loss of CECs 1–6 months after surgery was significantly correlated with IL-7, IP-10, MIP-1a and MIP-1b concentrations (-0.67, -0.48, -0.39, and -0.45, respectively, all P <0.01). CEC loss 1–12 months after surgery was significantly correlated with IL-1b, IL-7, IP-10 and RANTES concentrations (-0.46, -0.52, -0.48, and -0.43, respectively). Multiple regression analysis showed that IL-7 concentration was significantly associated with CEC loss 1–6 months after surgery (b = -0.65, P < 0.01) and IP-10 concentration was associated with CEC loss 1–12 months after surgery (β = -0.38, P < 0.05). These results suggest that not only inflammatory cytokines but also IL-7, a cytokine related to lymphocytes, may be involved in the depletion of CECs after DSAEK, particularly depletion that occurs relatively early.

Oxidative Stress Induces a Breakdown of the Cytoskeleton and Tight Junctions of the Corneal Endothelial Cells

Purpose: To investigate the impact of oxidative stress, which is a hallmark of Fuchs dystrophy, on the barrier function of the corneal endothelial cells. Methods: Experiments were carried out with cultured bovine and porcine corneal endothelial cells. For oxidative stress, cells were supplemented with riboflavin (Rf) and exposed to UV-A (15-30 min) to induce Type-1 photochemical reactions that release H₂O₂. The effect of the stress on the barrier function was assayed by transendothelial electrical resistance (TER) measurement. In addition, the associated changes in the organization of the microtubules, perijunctional actomyosin ring (PAMR), and ZO-1 were evaluated by immunocytochemistry, which was also repeated after direct exposure to H₂O₂ (100 μM, 1 h). Results: Exposure to H₂O₂ led to the disassembly of microtubules and the destruction of PAMR. In parallel, the contiguous locus of ZO-1 was disrupted, marking a loss of barrier integrity. Accordingly, a sustained loss in TER was induced when cells in the Rf-supplemented medium were exposed to UV-A. However, the addition of catalase (7,000 U/mL) to rapidly decompose H₂O₂ limited the loss in TER. Furthermore, the adverse effects on microtubules, PAMR, and ZO-1 were suppressed by including catalase, ascorbic acid (1 mM; 30 min), or pretreatment with p38 MAP kinase inhibitor (SB-203580; 10 μM, 1 h). Conclusions: Acute oxidative stress induces microtubule disassembly by a p38 MAP kinase-dependent mechanism, leading to the destruction of PAMR and loss of barrier function. The response to oxidative stress is reminiscent of the (TNF-α)-induced breakdown of barrier failure in the corneal endothelium.

Aqueous humour cytokine profiles after Descemet's membrane endothelial keratoplasty

The aim of this study was to compare aqueous humour (AqH) cytokine profiles before and after Descemet's membrane endothelial keratoplasty (DMEK) in eyes with bullous keratopathy (BK) and age-matched normal eyes. A total of 49 participants (mean age 75.0 ± 13.5 years) were divided into three groups: (1) BK patients scheduled for DMEK (BK group); (2) patients after DMEK (DMEK group; average postoperative time 1,018 ± 460 days); and (3) control participants without corneal endothelial disease scheduled for cataract surgery (control group). AqH (0.2 mL) was collected from all participants, and the levels of various AqH cytokines were simultaneously measured using a multiplex bead immunoassay. The DMEK group exhibited significantly lower concentrations of several pro-inflammatory cytokines, such as IL-1β, IL-5, IL-6, IL-10, and IL-8, and granulocyte colony stimulating factor than the BK group. In addition, the levels of IL-1β and IL-5 were significantly lower in the DMEK group than in the control group. The AqH levels of several pro-inflammatory cytokines were significantly reduced after DMEK, indicating that regeneration of the endothelial pump owing to the transplantation of a healthy endothelium might have a positive effect on anterior chamber inflammation.

[Evaluation of aqueous cytokine levels in eyes with Fuchs endothelial corneal dystrophy and bullous keratopathy]

PURPOSE

To evaluate cytokine levels in the aqueous humor (AH) of patients with Fuchs endothelial corneal dystrophy (FECD) and bullous keratopathy (BK).

MATERIAL AND METHODS

The study included 74 patients (74 eyes). The first group consisted of 31 patients (72.7±9.2 years) with FECD; the second group included 35 patients (72.4±9.1 years) with BK. The control group comprised 8 patients (74.3±4.1 years) with immature cataract. Before surgery, patients underwent pachymetry of the central cornea (RTvue-100 OCT, Optovue, USA). Patients of groups 1 and 2 underwent endothelial keratoplasty (DSAEK or DMEK), or penetrating corneal transplantation. Patients of the control group underwent phacoemulsification with implantation of intraocular lens. The initial stage of the surgery involved AH sample collection for evaluation of cytokine levels (IL-1β, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12(p70), IL-13, IL-17, G-CSF, GM-CSF, IFNγ, MCP-1, MIP-1β and TNF-α) by fluorescent flow cytometry using the Bio-Plex Pro Human Cytokine Panel, 17-plex (Bio-Rad, USA).

RESULTS

Multiplex analysis of the AH content did not show any statistically significant differences in cytokine levels between decompensated FECD and BK eyes. The levels of IL-6, IL-8, GM-CSF, IFNγ, MCP-1, MIP-1β were significantly elevated in FECD and BK eyes compared with healthy control. An insignificant deviation of IL-4 and IL-13 levels was detected in FECD and BK eyes compared with healthy controls. There were no significant differences in IL-1β and TNF-α (indicators of acute inflammation) between the study groups.

CONCLUSION

The obtained data confirm that FECD and BK are associated with disruption of ocular immune privilege that leads to chronic local inflammation, which in turn causes remodeling of the corneal tissues resulting in fibrosis.

Descemet Membrane Endothelial Keratoplasty Outcomes between Young and Old Graft Recipients

Purpose: To evaluated Descemet's membrane endothelial keratoplasty (DMEK) outcomes in young and old graft recipients.Materials and Methods: Data of 164 surgeries with a median age of 76 years (interquartile range 14 years) undergoing DMEK surgery between 2016 and 2018 was reviewed. Complications, graft survival, and visual acuity gain were compared between subjects in the 25th percentile (young recipients; aged 70 years and less, n = 21) and 75th percentile (old recipients; aged 85 years and over, n = 27) over the 2-year follow-up.Results: Young recipients had a lower rate of pre-operative glaucoma (14.3% vs. 51.9%, p = .014) and pseudophakic bullous keratopathy (9.5% vs. 59.3%, p < .001), and a higher rate of Fuchs endothelial dystrophy (57.1% vs. 14.8%, p = .002) and combined cataract extraction at the time of DMEK surgery (52.4% vs. 7.4%, p = .001) when compared to old recipients. Complications (primary graft failure, pupillary block, cystoid macular edema or infectious keratitis) were independent of graft recipient age. Descemet's membrane detachment requiring re-bubbling was observed more often in young compared to the old recipients (42.9% vs. 14.8%, p = .049). Visual acuity gain between the groups remained comparable up to 1-year, whereas at 2-years old recipients showed significantly declined visual acuity gains compared to the young recipients (0.14 ± 0.68 vs. 0.74 ± 0.49, p = .012). Graft recipients aged over 85 years had a considerably higher graft failure rate over the 24-months (40.7% vs. 4.8%, p = .006) and shorter graft survival time (p = .002; log-rank) when compared to the recipients aged under 70 years. After adjusting for potential confounders such as Fuchs endothelial dystrophy, pseudophakic bullous keratopathy and glaucoma, the recipients aged over 85 remained at higher risk for graft failure (HR = 17.278, 95% CI = 1.787-167.1, p = .014).Conclusions: In aged DMEK recipients, regardless of the low incidence of early postoperative complications, the rate of postoperative graft failure was significantly higher and graft survival shorter than in younger recipients.

Corneal endothelial status in different grades of late spontaneous in-the-bag IOL dislocation

PURPOSE

 To evaluate corneal endothelial cell density (ECD) in the eyes with different grades of late spontaneous in-the-bag intraocular lens (IOL) dislocation.

METHODS

 A prospective study included seventy-eight patients who applied for IOL dislocation. Overall 80 eyes were divided into four grades based on the in-the-bag IOL dislocation classification. All eyes underwent a complete ophthalmological examination. ECD was evaluated using in vivo corneal confocal microscopy.

RESULTS

 Median corneal ECD was 1929 (1022-2958) cells/mm2 of all the patients. The lowest number of ECD was in grade 2 (grade 1 median ECD 1990.33 (1182-2425.33) cells/mm2, grade 2-1577.0 (1022-2958) cells/mm2, grade 3-2205.84 (1259-2807.67) cells/mm2 and grade 4-2072.17 (1045-2581.0) cells/mm2). A statistically significant difference was observed between the median of ECD of grade 2nd and 3rd (p = 0.023). By grouping cases into those with and without glaucoma, we found that corneal ECD was significantly lower in eyes with glaucoma compared with eyes without glaucoma in grades 3 and 4 (p < 0.05), while in other grades, the difference did not reach the significance level. We divided the corneal ECD of all eyes into two categories ≤ 1500 cells/mm2 and  > 1500 cells/mm2. Logistic regression demonstrated that the odds of having corneal ECD less than 1500 cells/mm2 increased by 3.5-fold if patients with IOL dislocation had been diagnosed with glaucoma previously.

CONCLUSION

 Late spontaneous in-the-bag IOL dislocation reduced corneal ECD. Previously diagnosed glaucoma was the most common comorbidity. This condition has a significant impact on corneal ECD for patients with IOL dislocation.

Iris Posterior Synechiae After Descemet Membrane Endothelial Keratoplasty in Asian Eyes: Prevention and Management of Posterior Synechiae

OBJECTIVES

To evaluate the efficacy of a mydriatic agent for posterior synechiae after phacoemulsification and intraocular lens (IOL) implantation followed by Descemet membrane endothelial keratoplasty (staged DMEK).

METHODS

In this prospective study, the outcomes of DMEK with or without mydriasis (0.5% tropicamide and 0.5% phenylephrine hydrochloride [Mydrin-P; Santen, Osaka, Japan]) after the DMEK procedure were analyzed. Patients underwent IOL implantation approximately 4 weeks before DMEK. Six months after DMEK, the iris posterior synechiae severity score was evaluated based on the extent of posterior synechiae affecting the eight areas (45° each) of the pupillary rim (posterior synechiae score; grades 0-8). Best spectacle-corrected visual acuity, central corneal thickness, endothelial cell density, axial length, and the amount of air at the end of the surgery were also evaluated.

RESULTS

Fifteen eyes of 15 patients (mydriatic: n=8, control: n=7) were eligible for inclusion. Iris posterior synechiae were detected in all seven eyes (100.0%) in the control group, whereas they were noted in two eyes in the mydriatic group (25%). The mean iris posterior synechiae score was 0.69±1.20 in the mydriatic group and was significantly lower than that in the control group (4.57±0.90; P<0.001). There was no significant difference in other clinical factors. Although the incidence and scores of posterior synechiae in the control group were higher, the incidence was significantly reduced with the use of a mydriatic agent (in the mydriatic group).

CONCLUSIONS

Use of a mydriatic agent is an effective measure to prevent postoperative synechiae after DMEK.

SIRT1 Activation Using CRISPR/dCas9 Promotes Regeneration of Human Corneal Endothelial Cells through Inhibiting Senescence

Human corneal endothelial cells (hCECs) are restricted in proliferative capacity in vivo. Reduction in the number of hCEC leads to persistent corneal edema requiring corneal transplantation. This study demonstrates the functions of SIRT1 in hCECs and its potential for corneal endothelial regeneration. Cell morphology, cell growth rates and proliferation-associated proteins were compared in normal and senescent hCECs. SIRT1 was activated using the CRISPR/dCas9 activation system (SIRT1a). The plasmids were transfected into CECs of six-week-old Sprague–Dawley rats using electroporation and cryoinjury was performed. Senescent cells were larger, elongated and showed lower proliferation rates and lower SIRT1 levels. SIRT1 activation promoted the wound healing of CECs. In vivo transfection of SIRT1a promoted the regeneration of CECs. The proportion of the S-phase cells was lower in senescent cells and elevated upon SIRT1a activation. SIRT1 regulated cell proliferation, proliferation-associated proteins, mitochondrial membrane potential, and oxidative stress levels. In conclusion, corneal endothelial senescence is related with a decreased SIRT1 level. SIRT1a promotes the regeneration of CECs by inhibiting cytokine-induced cell death and senescence. Gene function activation therapy using SIRT1a may serve as a novel treatment strategy for hCEC diseases.

Five-Year Follow-up of First 11 Patients Undergoing Injection of Cultured Corneal Endothelial Cells for Corneal Endothelial Failure

PURPOSE

To report the safety and efficacy of a novel cell injection therapy using cultured human corneal endothelial cells (hCECs) for endothelial failure conditions via the report of the long-term 5-year postoperative clinical data from a first-in-humans clinical trial group.

DESIGN

Prospective observational study.

PARTICIPANTS

This study involved 11 eyes of 11 patients with pseudophakic endothelial failure conditions who underwent hCEC injection therapy between December 2013 and December 2014.

METHODS

All patients underwent follow-up examinations at 1 week, 4 weeks, 12 weeks, and 24 weeks and 1 year, 2 years, 3 years, 4 years, and 5 years after surgery. Specific corneal endothelial cell parameters (i.e., corneal endothelial cell density [ECD], coefficient of variation of area, and percentage of hexagonal cells) and central corneal thickness, best-corrected visual acuity (BCVA) on a Landolt C eye chart, and intraocular pressure (IOP) were recorded.

MAIN OUTCOME MEASURES

The primary outcome was the change in central ECD after cell injection therapy, and the secondary outcome was corneal thickness, BCVA, and IOP during the 5-year-postoperative follow-up period.

RESULTS

At 5 years after surgery, normal corneal endothelial function was restored in 10 of the 11 eyes, the mean ± standard deviation central corneal ECD was 1257 ± 467 cells/mm² (range, 601-2067 cells/mm²), BCVA improved significantly in 10 treated eyes, the mean visual acuity changed from 0.876 logarithm of the minimum angle of resolution before surgery to 0.046 logarithm of the minimum angle of resolution after surgery, and no major adverse reactions directly related to the hCEC injection therapy were observed.

CONCLUSIONS

The findings in this study confirmed the safety and efficacy of cultured hCEC injection therapy for up to 5 years after surgery.

Correlations between tear fluid and aqueous humor cytokine levels in bullous keratopathy

PURPOSE

To evaluate the correlation between tear fluid and aqueous humor (AqH) cytokine levels in eyes with bullous keratopathy (BK) and with normal endothelium.

METHODS

This prospective consecutive case-series study included 71 eyes of 71 patients: 31 eyes with BK, 18 eyes with non-BK corneal diseases, and 22 eyes with uncomplicated cataract (healthy controls). Total protein and cytokine (interleukin [IL]-1α, IL-1β, IL-4, IL-6, IL-8, IL-10, MIP-1α, MIP-1β, monocyte chemotactic protein [MCP]-1, E-selectin, P-selectin, soluble intercellular adhesion molecule [sICAM]-1, and IP-10) levels in the tear fluid and AqH were measured using multiplex beads immunoassay. The correlations between tear and AqH cytokine levels were assessed.

RESULTS

The AqH protein level was significantly higher in BK eyes (1.09 ± 0.08 mg/mL) than in non-BK (0.63 ± 0.11, P = 0.0004) and healthy control (0.62 ± 0.06, P = 0.0002) eyes. The tear total protein and IL-4 levels were significantly higher in the BK group compared to healthy controls (P = 0.0374 and 0.0032, respectively). The AqH IL-8 and sICAM-1 levels were significantly higher in the BK group compared to controls (P = 0.0001 and 0.0083, respectively). In BK eyes, the tear IL-4 level was significantly correlated with the MCP-1(r = 0.563, P = 0.001) and total protein (r = 0.589, P = 0.001) AqH levels. The tear IL-8 level was significantly correlated with the MCP-1(r = 0.598, p = 0.001) and IL-4 (r = 0.781, p < 0.0001) AqH levels in BK eyes. However, no significant correlations were found between tear and AqH cytokine levels in non-BK and healthy controls eyes.

CONCLUSIONS

The tear cytokine levels are correlated with those of AqH only in BK, but not in non-BK and healthy controls.

Pathological processes in aqueous humor due to iris atrophy predispose to early corneal graft failure in humans and mice

Corneal endothelial cell (CEnC) loss after corneal transplantation is the major cause of graft failure and remains a clinically relevant challenge to overcome. Accumulated knowledge derived from long-term clinical outcomes suggested that elevated protein levels in the aqueous humor are associated with CEnC loss. However, the full spectrum of driver proteins and molecular processes remains to be determined. Here, we defined the somatic microenvironmental landscape and cellular response across human aqueous humor in samples with poor corneal transplantation clinical outcomes using multiomics analyses and clarified specific driver alterations, including complement activation and disturbed energy homeostasis. These driver alterations were also confirmed in aqueous humor from a novel murine model that spontaneously develops iris atrophy, leading to CEnC loss. The application of the integrative multiomics performed in human samples to the novel murine model will help the development of therapeutic modalities for patients with CEnC loss after corneal transplantation.

Local synthesis of hepcidin in the anterior segment of the eye: A novel observation with physiological and pathological implications

PURPOSE

The avascular cornea, trabecular meshwork (TM), and lens obtain iron, an essential biometal, from the aqueous humor (AH). The mechanism by which this exchange is regulated, however, is unclear. Recently we reported that non-pigmented ciliary epithelial cells express ferroportin (Fpn) (Ashok, 2018b), an iron export protein modulated by hepcidin, the master regulator of iron homeostasis secreted mainly by the liver. Here, we explored whether ciliary epithelial and other cells in the anterior segment synthesize hepcidin, suggesting local regulation of iron exchange at this site.

METHODS

Human and bovine eyes were dissected to isolate the ciliary body (CB), corneal endothelial (CE), TM, lens epithelial (LE), and outer epithelial cell layer of the iris. Total mRNA and protein lysates were processed to evaluate the synthesis and expression of hepcidin, the iron regulatory peptide hormone, Fpn, the only known iron export protein, ceruloplasmin (Cp), a ferroxidase necessary for iron export, transferrin receptor (TfR), a major iron uptake protein, and ferritin, a major iron storage protein. A combination of techniques including reverse transcription polymerase chain reaction (RT-PCR) of total mRNA, Western blotting of protein lysates, and immunofluorescence of fixed tissue sections were used to accomplish these goals.

RESULTS

RT-PCR of isolated tissue samples revealed hepcidin-specific mRNA in the CB, TM, CE, and LE of the bovine eye. Western blotting of protein lysates from these tissues showed reactivity for hepcidin, Fpn, ferritin, and TfR. Western blotting and immunohistochemistry of similar tissues isolated from cadaveric human eyes showed expression of hepcidin, Fpn, and Cp in these samples. Notably, Fpn and Cp were expressed on the basolateral membrane of non-pigmented ciliary epithelial cells, facing the AH.

CONCLUSIONS

Synthesis and expression of hepcidin and Fpn in the ciliary epithelium suggests local regulation of iron transport from choroidal plexus in the ciliary body to the AH across the blood-aqueous barrier. Expression of hepcidin and Fpn in CE, TM, and LE cells indicates additional regulation of iron exchange between the AH and cornea, TM, and lens, suggesting autonomous regulation of iron homeostasis in the anterior segment. Physiological and pathological implications of these observations are discussed.

A prospective, randomized clinical study comparing accelerated corneal collagen crosslinking with 5% NaCl hypertonic saline for bullous keratopathy in Asian eyes

BACKGROUND

We compared the clinical outcomes of accelerated corneal collagen crosslinking (CXL) and 5% NaCl hypertonic saline (HS) for the treatment of symptomatic bullous keratopathy (BK).

METHODS

A randomized controlled trial was held at Department of Ophthalmology, Tokyo Dental College Ichikawa General Hospital, Chiba, Japan. Twenty-three eyes of 23 consecutive patients with symptomatic BK were enrolled. The etiology of BK included pseudophakic BK, previous keratoplasty, previous endotheliitis, previous glaucoma surgery, trauma, herpes infection, as well as unknown causes. Eleven eyes received epi-off accelerated CXL (with epithelial abrasion and 18 mW/cm ultraviolet A irradiation for 5 minutes) and 12 eyes received HS instillation. In addition to the usual ophthalmic examination, the best-corrected visual acuity (BCVA) and central corneal thickness (CCT) were determined. The CCT was measured using anterior segment optical coherence tomography before and up to 6 months after treatments. Subjective symptoms of pain, blurred vision, photophobia, and irritation were also recorded.

RESULTS

The follow-up was completed for all patients in the CXL group. However, 6 patients in the HS group requested CXL treatments after 3 months. The BCVA was not significantly changed during the study periods in both groups. The CCT was significantly thinner in the CXL group compared to the HS group at 1 and 6 months (P = .015 and 0.144, respectively). Among the subjective symptoms recorded, irritation was significantly lower in the CXL group at 1 month (P = .013).

CONCLUSIONS

Accelerated CXL may produce transient improvement in pain and corneal edema in patients with BK.

Descemet's membrane endothelial keratoplasty for pseudoexfoliation syndrome: a case series

Background

To evaluate the clinical outcomes and features of Descemet’s membrane endothelial keratoplasty (DMEK) for eyes with pseudoexfoliation syndrome (PEX).

Methods

In this retrospective study, 37 DMEK cases were reviewed from available medical records. Patients who exhibited endothelial dysfunction derived from PEX or Fuchs endothelial corneal dystrophy (FECD) and successfully underwent cataract surgery about four weeks before DMEK were enrolled. The best spectacle-corrected visual acuity (BSCVA), central corneal thickness (CCT), endothelial cell density (ECD), and incidence of intra-operative/post-operative complications of DMEK were analyzed.

Results

This study included 14 eyes of 14 patients (PEX: n = 6, FECD: n = 8). There was no primary graft failure. In the PEX group, BSCVA improved from 0.67 ± 0.28 at the preoperative point to 0.43 ± 0.14 at 1 month, 0.27 ± 0.10 at 3 months, and 0.19 ± 0.08 at 6 months after DMEK. The donor corneal ECD was 2704 ± 225 cells/mm² at the preoperative point and decreased to 1691 ± 498 cells/mm² at 1 month, 1425 ± 366 cells/mm² at 3 months, and 1281 ± 340 cells/mm² (52.7 ± 11.7% less than ECD of the donor graft) at 6 months after DMEK. None of the patients required rebubbling. When compared with the FECD group, no statistical difference was observed in CCT (p = 0.821); BSCVA (p = 0.001) and the reduction rate of ECD (p = 0.010) were relatively worse.

Conclusions

DMEK is effective for the treatment of endothelial dysfunction due to PEX.

Electronic supplementary material

The online version of this article (10.1186/s12886-019-1130-1) contains supplementary material, which is available to authorized users.

Inflammatory Response in Dry Eye

Purpose

Dry eye is a major ocular pathology worldwide. Although dry eye is a multifactorial disease, recent studies have shown that chronic immunologic processes have a pivotal role in its pathogenesis, characterized by the infiltration of immune cells in the lacrimal glands, elevated levels of tear inflammatory cytokines, and increased density of immune cells in the cornea and conjunctiva. This review describes the recent advances in understanding the relationship between dry eye and inflammation.

Methods

This narrative review is based on searches of recent international literature using terms related to the immune response in dry eye, and includes clinical trials, animal experiments, and expert reviews.

Results

Although dry eye presents clinically as tear film instability associated with corneal/conjunctival epithelial disorders, Meibomian gland dysfunction, and decreased visual function, recent laboratory and clinical studies have indicated inflammation in the lacrimal glands, Meibomian glands, conjunctiva, cornea, and aqueous tears. Furthermore, inflammation at these locations leads to conjunctival goblet cell apoptosis, corneal epithelial barrier disruption, and corneal nerve damage. These inflammatory outcomes can be exacerbated by intrinsic and extrinsic factors, such as aging, sex steroid hormone, autoimmune diseases, contact lens use, visual display terminals, and dry environment.

Conclusions

Recent advances in dry eye research have revealed the inflammatory process and its pathogenesis, which has been proposed as an "inflammatory vicious cycle" of dry eye. Comprehensive assessment of dry eye based on inflammation will improve the selection of treatments and help break the inflammatory cycle in clinical settings.

Immune privilege in corneal transplantation

Corneal transplantation is the most successful solid organ transplantation performed in humans. The extraordinary success of orthotopic corneal allografts, in both humans and experimental animals, is related to the phenomenon of "immune privilege". Inflammation is self-regulated to preserve ocular functions because the eye has immune privilege. At present, three major mechanisms are considered to provide immune privilege in corneal transplantation: 1) anatomical, cellular, and molecular barriers in the cornea; 2) tolerance related to anterior chamber-associated immune deviation and regulatory T cells; and 3) an immunosuppressive intraocular microenvironment. This review describes the mechanisms of immune privilege that have been elucidated from animal models of ocular inflammation, especially those involving corneal transplantation, and its relevance for the clinic. An update on molecular, cellular, and neural interactions in local and systemic immune regulation is provided. Therapeutic strategies for restoring immune privilege are also discussed.

Effect of topical steroid instillation on central corneal thickness in eyes with bullous keratopathy

PURPOSE

To examine the effects of topical steroid instillation on central corneal thickness in eyes with bullous keratopathy (BK).

STUDY DESIGN

Retrospective case series METHODS: Consecutive patients with BK who did not wish to receive corneal transplantation and were treated with 0.1% betamethasone eyedrops were included. Patients with BK treated with 5% sodium chloride (hypertonic saline) eyedrops served as controls. Central corneal thickness (CCT), best-corrected visual acuity (BCVA), intraocular pressure (IOP), BK etiology, and clinical courses from medical records were retrospectively reviewed. We compared the two groups for differences in CCT, BCVA and IOP before treatment and 2 weeks, 1 month, and 3 months after treatment.

RESULTS

Eighteen eyes of 18 patients who were treated with betamethasone and 18 eyes of 18 patients who were treated with hypertonic saline were included. There was no significant difference in CCT between the two groups before treatment. The reduction of CCT in the betamethasone group was significantly larger than in the hypertonic saline group at 2 weeks (p = 0.002), 1 month (p = 0.02), and 3 months (p = 0.001) after treatment. Complications such as infectious keratitis and IOP rise did not occur during the observation period.

CONCLUSIONS

Topical steroid instillation reduced central corneal thickness in eyes with BK.

Association of Iris Damage With Reduction in Corneal Endothelial Cell Density After Penetrating Keratoplasty

PURPOSE

To evaluate the effect of iris damage on endothelial cell loss in the early phase after penetrating keratoplasty (PKP).

METHODS

This prospective consecutive study included 74 patients who underwent PKP without graft rejection during the follow-up period. Endothelial cell density (ECD) was measured using specular microscopy at 1, 3, 6, and 12 months after PKP. Iris damage scores (IDSs) were determined on the basis of slit-lamp microscopy or anterior segment optical coherence tomography imaging. Graft survival rates were compared among the different IDSs. Using multivariate analysis, the factors influencing postoperative ECD were assessed, taking into consideration the presence of glaucoma, history of graft failure, donor age, and graft ECD as independent variables.

RESULTS

Graft ECD decreased from 2674 ± 329 cells/mm to 2114 ± 570 at 1 month, 1907 ± 629 at 3 months, 1669 ± 738 at 6 months, and 1404 ± 792 at 12 months (all, P < 0.0001). ECD at 12 months was associated with the IDS (β = -0.444, P < 0.0001), graft ECD (β = 0.309, P = 0.003), and history of graft failure (β = -0.251, P = 0.016). The IDS was significantly correlated with %ECD loss at 1 month (r = 0.427, P = 0.003), at 3 months (r = 0.376, P = 0.002), at 6 months (r = 0.301, P = 0.013), and at 12 months (r = 0.517, P < 0.0001). The graft survival rates in eyes with severe iris damage were significantly lower than those in eyes with either no or mild iris damage (P < 0.0001).

CONCLUSIONS

Severe iris damage is associated with rapid reduction in ECD and graft endothelial failure after PKP.

Cytokine Levels in the Aqueous Humor Are Associated With Corneal Thickness in Eyes With Bullous Keratopathy

PURPOSE

We sought to investigate the association between the severity of bullous keratopathy and proinflammatory cytokine levels in the aqueous humor (AqH).

DESIGN

Cross-sectional study.

METHODS

This study included a total of 95 eyes: 62 with bullous keratopathy and 33 that underwent cataract surgery. Central corneal thickness (CCT) and central corneal volume within 4 and 6 mm (CCV_4mm and CCV_6mm, respectively) were determined using anterior segment optical coherence tomography. A total of 95 AqH samples were collected at the beginning of surgery. The levels of cytokines (interleukins [ILs]-1α, -1β, -4, -6, -8, -10, -12p70, -13, -17A, interferon [IFN]-α, IFN-γ, monocyte chemotactic protein [MCP]-1, E-selectin, P-selectin, and soluble intercellular adhesion molecule-1 [sICAM-1]) in the AqH were measured using multiplex beads immunoassay. We evaluated the correlation among AqH cytokine levels, CCT, CCV_4mm, and CCV_6mm in eyes with bullous keratopathy.

RESULTS

The levels of protein, ILs-4, -6, -8, -10, -12p70, and -17A, MCP-1, IFN-γ, E-selectin, P-selectin, and sICAM-1 were significantly higher in eyes with bullous keratopathy compared with those of the normal control subjects (all P < .0025). CCT was significantly correlated with the levels of IL-13 (r = 0.551, P = .0009) and sICAM-1 (r = 0.448, P = .0005). CCV_4mm was significantly correlated with the levels of IL-13 (r = 0.514, P = .0022) and sICAM-1 (r = 0.404, P = .0019). CCV_6mm was significantly correlated with the level of sICAM-1 (r = 0.459, P = .0003).

CONCLUSION

The severity of corneal edema in eyes with bullous keratopathy was associated with the levels of specific cytokines in the AqH.

Long-term (≥10 years) results of corneal endothelial cell loss after cataract surgery

OBJECTIVE

To investigate the extent of long-term corneal endothelial loss after uneventful cataract surgery and the factors associated with decreases in corneal endothelial cell density (ECD).

DESIGN

Retrospective case series.

PARTICIPANTS

Patients who had undergone uncomplicated cataract surgery.

METHODS

This study comprised 81 eyes of 48 patients who had undergone cataract surgery >10 years previously by a single surgeon with the same intraocular lens and visited the outpatient clinic between January 2014 and February 2017. Long-term (≥10 years) changes in visual outcome and ECD after uncomplicated cataract surgery were evaluated. To analyze factors correlated with endothelial cell loss, preoperative biometric variables, including cataract grade, anterior chamber depth, axial length, and postoperative corneal edema, were evaluated.

RESULTS

The mean ± SD preoperative and long-term postoperative ECD was 2793 ± 351.09 and 2148 ± 478.38 cells/mm², respectively. The mean follow-up period was 11.08 ± 1.06 years and 10-year ECD loss rate was 20.62 ± 13.63%. Preoperative nuclear firmness was most statistically correlated with 10-year ECD loss (β-coefficient 0.394 [95% CI 3.402-9.448]; p < 0.001). The degree of postoperative corneal edema was also a significant predictive factor of 10-year ECD loss after cataract surgery (β-coefficient 0.378 [95% CI 2.854-8.358]; p = 0.002).

CONCLUSION

Preoperative nuclear firmness and postoperative corneal edema were predictors of long-term (≥10 years) endothelial cell loss and severe endothelial cell loss after cataract surgery. It is important to remember that eyes with increased nuclear firmness have a significantly higher risk of long-term enhanced ECL.