Project description:Purpose:The purpose of this study was to evaluate the effect of removal of Descemet's basement membrane and endothelium compared with removal of the endothelium alone on posterior corneal fibrosis. Methods:Twelve New Zealand White rabbits were included in the study. Six eyes had removal of the Descemet's membrane-endothelial complex over the central 8 mm of the cornea. Six eyes had endothelial removal with an olive-tipped cannula over the central 8 mm of the cornea. All corneas developed stromal edema. Corneas in both groups were cryofixed in optimum cutting temperature (OCT) formula at 1 month after surgery. Immunohistochemistry (IHC) was performed for α-smooth muscle actin (SMA), keratocan, CD45, nidogen-1, vimentin, and Ki-67, and a TUNEL assay was performed to detect apoptosis. Results:Six of six corneas that had Descemet's membrane-endothelial removal developed posterior stromal fibrosis populated with SMA+ myofibroblasts, whereas zero of six corneas that had endothelial removal alone developed fibrosis or SMA+ myofibroblasts (P < 0.01). Myofibroblasts in the fibrotic zone of corneas that had Descemet's membrane-endothelial removal were undergoing both mitosis and apoptosis at 1 month after surgery. A zone between keratocan+ keratocytes and SMA+ myofibroblasts contained keratocan-SMA-vimentin+ cells that were likely CD45- corneal fibroblasts and CD45+ fibrocytes. Conclusions:Descemet's basement membrane has an important role in modulating posterior corneal fibrosis after injury that is analogous to the role of the epithelial basement membrane in modulating anterior corneal fibrosis after injury. Fibrotic areas had myofibroblasts undergoing mitosis and apoptosis, indicating that fibrosis is in dynamic flux.
Project description:PurposeTo determine the cost-effectiveness of Descemet's membrane endothelial keratoplasty (DMEK) compared with Descemet's stripping automated endothelial keratoplasty (DSAEK) in the United States.DesignCost-effectiveness analysis in a surgical center in the United States.ParticipantsBinocular adult patient undergoing endothelial keratoplasty.MethodsA base case of a 70-year-old man undergoing his first endothelial keratoplasty for bilateral Fuchs endothelial dystrophy. The cost-effectiveness of DMEK was compared with DSAEK over a 15-year time horizon. The incidences and costs of complications were derived from PubMed English literature searches, Medicare reimbursements, and average wholesale prices. All costs were discounted 3% per annum and adjusted for inflation to 2018 U.S. dollars. Uncertainty was evaluated using deterministic and probabilistic sensitivity analyses.Main outcome measuresIncremental cost-effectiveness ratios and incremental cost-utility ratios, measured in cost per quality-adjusted life-years (QALYs).ResultsPerforming a DMEK instead of a DSAEK generated an extra 0.4 QALYs over a 15-year period. From a societal and third-party payer perspective, DMEK was cost-saving when compared with DSAEK in improving visual acuity in the base case. Probabilistic sensitivity analyses with variations in the costs and rebubble rates revealed that DMEK was cost-saving compared with DSAEK in 38% of iterations and was within a societal willingness-to-pay threshold of $50 000 in 98% of models.ConclusionsFrom the societal and third-party payer perspectives in the United States, DMEK generated greater utilities and was less costly than DSAEK. Therefore, DMEK was the dominant procedure and was cost-saving with respect to DSAEK. The economic model was robust based on sensitivity analyses.
Project description:Purpose:To describe a case of bilateral, sequential placoid choroidopathy following uncomplicated Descemet's membrane endothelial keratoplasty (DMEK). Observations:A 49-year old woman presented with flashing lights and central visual field scotomas after undergoing uncomplicated DMEK combined with cataract surgery for Fuch's endothelial dystrophy in the right eye. She was found to have placoid choroidopathy responsive to systemic steroids and for which a comprehensive work-up was unrevealing. Three and a half months later, she underwent DMEK surgery in the fellow eye and again developed placoid choroidopathy in the operated eye. Work-up was again unrevealing and the lesion followed a similar course to the first eye on systemic steroids. Over the course of seven (right eye) and three and a half months (left eye) of follow-up, the uncorrected visual acuity was 20/20 bilaterally and the retinal lesions had modestly improved. Conclusions and Importance:We report a case of placoid choroidopathy following uncomplicated DMEK combined with cataract surgery in both eyes of a single patient. This case expands upon the reported complications following DMEK surgery and suggests a need to remain aware of posterior segment complications following endothelial keratoplasty.
Project description: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.
Project description:Based on current evidence, the efficiency and safety of Descemet's membrane endothelial keratoplasty (DMEK) was compared with that of Descemet's stripping endothelial keratoplasty (DSEK).Pubmed, Embase, Web of Science, the Cochrane Database and conference abstracts were comprehensively searched for studies that compared the efficacy and safety of DMEK and DSEK. The efficacy outcome was the postoperative best-corrected visual acuity (BCVA). The safety outcomes included the postoperative endothelial cell density (ECD) and complications such as graft detachment, graft rejection, graft failure, postoperative elevated intraocular pressure (IOP), tissue loss, etc. The outcomes were pooled using random-effects models with Stata 13.0 software. Heterogeneity was qualified with Q statistic and I2/H2 statistic. Publication bias was assessed using funnel plot, Begg rank correlation test, and Egger or Horbard linear regression.19 articles were eligible, and 1124 eyes and 1254 eyes were included in the DMEK and DSEK groups, respectively. The overall pooled estimates showed a significantly better postoperative BCVA, a comparable ECD and an increased graft detachment rate in the DMEK group compared with the DSEK group (BCVA: mean difference (MD) = -0.15, 95% CI = -0.19 to -0.11, P<0.001; ECD: MD = 14.88, 95% CI = -181.50 to 211.27, P = 0.882; graft detachment rate: OR = 4.56, 95% CI = 2.43 to 8.58, P<0.001). Except for the postoperative ECD, which was changed to be higher in the DSEK group than the DMEK group, the learning curve did not have a marked effect on the comparison outcome of the BCVA and graft detachment rate based on the estimates pooled from studies that collected data during the DMEK learning phase (ECD (learning curve): MD = -361.24, 95% CI = -649.42 to -73.07, P = 0.014).Although DMEK is a more technically difficult and challenging procedure, it may represent a safe and more efficient alternative to DSEK for the treatment of corneal endothelial diseases, even during its learning curve.
Project description:To investigate the topographic characteristics of the posterior corneal surface after Descemet's endothelial membrane keratoplasty (DMEK) and Descemet's stripping automated endothelial keratoplasty (DSAEK) and their effects on postoperative visual acuity.Nineteen eyes of 19 patients after DMEK, 23 eyes of 23 patients after DSAEK, and 18 eyes of 18 control subjects were retrospectively analyzed. Best spectacle-corrected visual acuity (BSCVA), aberration factors (higher-order aberrations [HOAs], spherical aberrations [SAs], and coma aberrations [Comas] at 6.0 mm) were evaluated preoperatively and at 1, 3, and 6 months postoperatively. The posterior refractive pattern of the topography map was classified into 5 grades (0-5) (posterior color grade) using anterior segment optical coherence tomography. Correlations between BSCVA and some factors (abbreviation factors, posterior color grade) were analyzed.BSCVA was significantly better after DMEK than after DSAEK (P < 0.001). Posterior HOAs, SAs, and Comas after each type of endothelial keratoplasty were significantly greater compared to control (P < 0.01). Posterior HOAs, total/anterior/posterior SAs, and posterior color grade were significantly lower in the DMEK group than in the DSAEK group at 3 months (P < 0.024 [posterior HOAs], P = 0.047 [total SA], P < 0.001 [anterior SAs], P = 0.021 [posterior SAs], and P < 0.001 [posterior color grade]) and 6 months postoperatively (P = 0.034 [posterior HOAs], P < 0.001 [total SAs], P < 0.001 [anterior SAs], P = 0.013 [posterior SAs], and P = 0.004 [posterior color grade]). BSCVA was significantly correlated with HOAs, SAs, and posterior color grade (P < 0.001 for all except anterior HOAs [P = 0.004]).High posterior color grades were associated with larger aberration factors and had a negative effect on visual function after endothelial keratoplasty. Rapid improvement of visual function after DMEK may be attributed to less change at the posterior surface.
Project description: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.
Project description:Descemet's membrane (DM) helps maintain phenotype and function of corneal endothelial cells under physiological conditions, while little is known about the function of DM in corneal endothelial wound healing process. In the current study, we performed in vivo rabbit corneal endothelial cell (CEC) injury via CEC scraping, in which DM remained intact after CECs removal, or via DM stripping, in which DM was removed together with CECs. We found rabbit corneas in the CEC scraping group healed with transparency restoration, while there was posterior fibrosis tissue formation in the corneas after DM stripping on day 14. Following CEC scraping on day 3, cells that had migrated toward the central cornea underwent a transient fibrotic endothelial-mesenchymal transition (EMT) which was reversed back to an endothelial phenotype on day 14. However, in the corneas injured via DM stripping, most of the cells in the posterior fibrosis tissue did not originate from the corneal endothelium, and they maintained fibroblastic phenotype on day 14. We concluded that corneal endothelial wound healing in rabbits has different outcomes depending upon the presence or absence of Descemet's membrane. Descemet's membrane supports corneal endothelial cell regeneration in rabbits after endothelial injury.
Project description:This paper reports a case of spontaneous Descemet's Membrane (DM ) detachment 20-years after penetrating keratoplasty (PK). The patient presented with acute onset blurred vision in the right eye associated with mild ocular discomfort. There was no prior history of trauma. The patient had undergone PK in the right eye 20 years back. Detailed ophthalmic examination showed best corrected visual acuity of hand movements close to face in the right eye and 20/80 in the left eye. The right eye showed diffuse graft edema but no congestion, epithelial defect, or loss of continuity of graft-host junction to suggest a traumatic etiology. Anterior segment optical coherence tomography showed DM break with a detachment in the right eye, which was treated with an intracameral C3F8 injection. DM break with detachment post-PK has been very sparsely reported in literature and is an important differential to remember when faced with an edematous graft, in addition to the diagnosis of graft rejection or failure.
Project description:Endothelial keratoplasty (EK) has supplanted the penetrating keratoplasty procedure for corneal endothelial disorders. A review of literature on pre-descemet's EK, that is, a latest iterant in EK is described along with our experiences.