Corneal Endothelial Cell Loss Research Articles

Effects of Cumulative Dissipated Energy on Corneal Endothelial Cells in Phacoemulsification Based on Nucleus Sclerosis

Purpose: To investigate changes in corneal endothelial cell (CEC) by cumulative dissipated energy (CDE) during phacoemulsification.Methods: Based on the degree of nucleus sclerosis (NS), changes in CECs were compared preoperatively and at 1 and 3 months postoperatively in 67 eyes that underwent phacoemulsification.Results: The mean CDE used during surgery was 4.30 ± 2.31. A comparison of the surgical measurements before and 1 month after surgery revealed significant differences in the cell density (CD) and coefficient of variation (CV) (<i>p</i> < 0.001, 0.011, respectively). The CD showed significant differences among NS grades 2–6 (<i>p</i> < 0.001). The CDE increased significantly with higher NS grades (r = 0.809, <i>p</i> < 0.001). Within the same NS grade, there was a positive correlation between higher CDE and greater CEC loss (r = 0.559, <i>p</i> = 0.001). CD changes were significantly associated with increasing CDE (r = 0.612, <i>p</i> < 0.001). The CD loss also increased significantly from NS2 to NS6 (<i>p</i> < 0.001). At 3 months postoperatively, surgical measurements revealed a significant decrease in CD with increasing NS grade (<i>p</i> = 0.010).Conclusions: CDE increased with higher NS grades and there was a positive correlation between CDE and CEC loss. Therefore, surgeons should plan surgical techniques preoperatively to minimize CDE as NS increases. Additionally, it is important to assess CEC damage postoperatively based on surgical measurements in patients with high intraoperative CDE.

Modulation of ATM enhances DNA repair in G2/M phase of cell cycle and averts senescence in Fuchs endothelial corneal dystrophy

Fuchs Endothelial Corneal Dystrophy (FECD) is an aging disorder characterized by expedited loss of corneal endothelial cells (CEnCs) and heightened DNA damage compared to normal CEnCs. We previously established that ultraviolet-A (UVA) light causes DNA damage and leads to FECD phenotype in a non-genetic mouse model. Here, we demonstrate that acute treatment with chemical stressor, menadione, or physiological stressors, UVA, and catechol estrogen (4-OHE2), results in an early and increased activation of ATM-mediated DNA damage response in FECD compared to normal CEnCs. Acute stress with UVA and 4OHE2 causes (i) greater cell-cycle arrest and DNA repair in G2/M phase, and (ii) greater cytoprotective senescence in NQO1−/− compared to NQO1+/+ cells, which was reversed upon ATM inhibition. Chronic stress with UVA and 4OHE2 results in ATM-driven cell-cycle arrest in G0/G1 phase, reduced DNA repair, and cytotoxic senescence, due to sustained damage. Likewise, UVA-induced cell-cycle reentry, gamma-H2AX foci, and senescence-associated heterochromatin were reduced in Atm-null mice. Remarkably, inhibiting ATM activation with KU-55933 restored DNA repair in G2/M phase and attenuated senescence in chronic cellular model of FECD lacking NQO1. This study provides insights into understanding the pivotal role of ATM in regulating cell-cycle, DNA repair, and senescence, in oxidative-stress disorders like FECD.

Removal of Metallic Foreign Bodies with Complete Penetration of the Cornea: Introduction of a New Approach.

The purpose of this study was to present a new ab interno approach and relevant case series using a polymer-tipped cannula for the removal of metallic foreign bodies that penetrate the full thickness of the cornea and are located in the posterior corneal region. Corneal foreign bodies located on the posterior side of the cornea were gently pushed toward the epithelial side with a polymer-tipped cannula placed using a side-port incision, to be removed without damaging the corneal endothelial layer. The polymer-tipped cannula is specially angled to keep it at a distance from the corneal endothelial layer. In this way, unnecessary endothelial contact and the risk of possible endothelial loss are minimized. The foreign body was held by the epithelium with forceps and carefully removed along the corneal perforation line. This technique was performed in 5 eyes of 5 patients. The mean patient age at the time of surgery was 38.0 ± 12.1 years (range, 28-59 years). Anterior segment optical coherence tomography showed a metallic foreign body and its shadow that completely penetrated the cornea with the deterioration of the endothelial layer in all cases. In all cases, the corneal foreign body was successfully removed. While preoperative corneal endothelial cell density was 3040.0 ± 512.8 cells/mm2, postoperative corneal endothelial cell density was 2927.2 ± 608.1 cells/mm2 at the third postoperative month, and there was no significant corneal endothelial cell loss in any of the cases (P = 0.31). The ab interno approach, performed with a polymer-tipped cannula for the removal of corneal foreign bodies that penetrate deeply, stands out as an important surgical method. This method offers a reliable and effective solution by preventing the foreign body from falling into the anterior chamber and minimizing endothelial damage.

Corneal Clarity after Phacoemulsification: Nuclear Management by Stop and Chop vs Divide and Conquer Methods

Background: Restoration of effective vision is the principal aim of all modalities of cataract surgery including Phacoemulsification. Energy level of ultrasonic power in Phacoemulsification and turbulence of fluid in the anterior chamber plays an important role in corneal endothelial cell loss influencing post-operative corneal clarity. Objectives: To compare post-operative corneal clarity after Phacoemulsification by two techniques of nuclear divisions: stop and chop with divide and conquer. Methodology: This prospective observational study was conducted at Shaheed Monsur Ali Medical College and Hospital, Uttara, Dhaka from January, 2023 to June, 2023. The study was carried out on 30 outdoor patients undergoing Phacoemulsification at SMAMCH and Mirpur Eye Hospital, Dhaka. The selected patients underwent detailed ocular and systemic examinations with relevant investigations and divided equally into two groups comprising of 15 in group A (stop and chop) and 15 in group B (divide and conquer). Phacoemulsification was done in all patients by a single expert surgeon. Patients were followed up after 1 week, 4 weeks and 12 weeks of surgery. Corneal endothelial cell count and central corneal thickness were assessed in each visit. Mean value of these mentioned parameters in follow-up periods were compared between two groups. Unpaired t test was done to assess the level of significance. Results: The mean age + standard deviation (SD) of the study subjects was 61.5+2 years, out of which 13(43.33%) were males and other 17(56.67%) females. Pre-operative value of mean endothelial cell count was 2620+70.20/mm2 in group A and 2625+71.10/mm2 in group B. Postoperative mean value + SD of endothelial cell count was 2420+68.90/mm2, 2345+66.64/mm2, 2310+66.04/mm2 respectively after 1 week, 4 weeks and 12 weeks of surgery in group A and 2410+69.54/mm2, 2340 +6587/mm2, 2310+64.45/mm2 in group B respectively. Mean value + SD of central corneal thickness was 545+40.50 micrometer, 535+40.02 micrometer and 532+39.85 micrometer respectively after 1 week, 4 weeks and 12 weeks after surgery in group A and 547+43.98 micrometer, 537+41.23 micrometer and 533+40.63 micrometer respectively in group B. Conclusion: Quantitative assessment and comparison of endothelial cell count and central corneal thickness shows that at end of the study, there was no remarkable difference in mean values of endothelial cell count and central corneal thickness between two methods. Journal of Monno Medical College December, 2023; 9 (2):37-40

Pathogenesis of Fuchs endothelial corneal dystrophy, the fibrillar layer and individualized treatment

Fuchs endothelial corneal dystrophy (FECD) is agenetic and age-associated corneal disease characterized by an accelerated loss of corneal endothelial cells and an increased subendothelial deposition of extracellular matrix (ECM). Clinically, advanced disease leads to corneal edema with subsequent reduction in visual acuity. In the majority of patients with advanced FECD, afibrillar layer (FL) appears on the posterior corneal surface. This FL is mostly localized in the inferotemporal corneal quadrant, marks areas with significantly reduced endothelial cell density and increased corneal thickness in the sense of edema and can be visualized and measured using Scheimpflug backscatter analysis due to increased backscatter. FECD is currently the most common indication for corneal transplantation worldwide, usually in the form of Descemet membrane endothelial keratoplasty (DMEK). New treatment approaches include variations of DMEK surgery such as hemi- or quarter DMEK with individualized and smaller grafts or Descemet membrane stripping only (DSO). In the future, clinical imaging of the FL as aparticularly affected endothelial area could be important for FECD progression assessment and planning of surgical interventions. This article provides an overview of the current state of research on the clinical aspects, pathogenesis, fibrillar layer and individualized treatment of FECD.

Compared to Trabeculectomy, Ex-Press® Surgery Significantly Decreased the Loss of Corneal Endothelial Cell Density in Low-Intraocular-Pressure Glaucoma: 3-Year Follow-Up.

We compared the corneal endothelial cell loss between trabeculectomy (Trab) and Ex-Press® surgery (EXP) for low-intraocular pressure (IOP) glaucoma patients. This was a single-facility retrospective study. We analyzed the cases of patients with primary open-angle glaucoma (POAG) and pre-operative IOP ≤ 21 mmHg who had undergone Trab or EXP surgery and were followed for >3 years. Noncontact specular microscopy was used to determine the corneal endothelial cell density (CED) before and after Trab or EXP surgery. We measured the CED at 12, 24, and 36 months post-surgery. We compared the CED values and CED survival ratio after both surgeries using paired t-tests. We included 39 eyes that underwent Trab and 36 eyes that underwent EXP surgery. In the Trab group, the mean CED value had decreased from 2333 ± 399 at baseline to 2066 ± 587 cells/mm2 after 3 years. In the EXP group, the mean CED value had decreased from 2320 ± 393 at baseline to 2229 ± 460 cells/mm2 after 3 years. The survival ratio of CED at >3 years was 89.3 ± 14.2% (Trab group) and 95.6 ± 11.1% (EXP group); compared to the Trab surgery, the EXP surgery thus significantly decreased the CED loss (p = 0.037). No case resulted in bullous keratopathy. Compared to trabeculectomy, Ex-Press® surgery appears to be a safer surgical method with regard to the endothelial cell loss risk.

Corneal Endothelial Cell Loss During Uneventful Cataract Surgery in Hispanics Versus Non-Hispanics.

Limited information exists on the possible effects of ethnicity on corneal endothelial cell parameters and their changes during cataract surgery. Thus, we evaluated corneal endothelial cell density (ECD) and endothelial cell loss (ECL) during surgery for senile cataract in Hispanic and non-Hispanic White adults. This retrospective study included 312 eyes of 227 patients ≥50 years who underwent phacoemulsification with intraocular lens implantation for senile cataract. Preoperatively and 1 to 2 months after surgery, specular microscopy was performed to measure ECD, coefficient of variation (CV), and hexagonal cell percentage (HEX). Regression analysis was used to compare baseline values as well as surgery-related changes in corneal endothelial cell parameters between Hispanic and non-Hispanic patients considering demographics, biometric parameters, and intraoperative cumulative dissipated energy (CDE). There were 109 Hispanics and 118 non-Hispanics. Anterior chamber depth (ACD) was significantly lower in Hispanics (3.12±0.36 mm) compared with non-Hispanics (3.25±0.37 mm, P=0.009). There were no significant differences in baseline ECD between Hispanics (2,547±365 cells/mm2) and non-Hispanics (2,483±380 cells/mm2, P=0.17). There were also no significant differences in ECL (16.8%±17.0% vs. 17.4%±18.1%, P=0.46), increase in CV (3.8%±20.7% vs. 1.5%±21.6%, P=0.51), and decrease in HEX (-2.7%±8.5% vs. -1.8%±7.0%, P=0.33) between these two groups. Regression analysis showed that ECL was associated with a shallower ACD (P=0.003), a higher CDE (P<0.001), but not with ethnicity (P=0.46). There are no significant differences in ECD and ECL between Hispanics and non-Hispanics undergoing cataract surgery. Although Hispanics have a shallower ACD, the ethnic difference seems to be clinically insignificant.

TCF4 trinucleotide repeat expansions and UV irradiation increase susceptibility to ferroptosis in Fuchs endothelial corneal dystrophy

Fuchs endothelial corneal dystrophy (FECD), the leading indication for corneal transplantation in the U.S., causes loss of corneal endothelial cells (CECs) and corneal edema leading to vision loss. FECD pathogenesis is linked to impaired response to oxidative stress and environmental ultraviolet A (UVA) exposure. Although UVA is known to cause nonapoptotic oxidative cell death resulting from iron-mediated lipid peroxidation, ferroptosis has not been characterized in FECD. We investigated the roles of genetic background and UVA exposure in causing CEC degeneration in FECD. Using ungenotyped FECD patient surgical samples, we found increased levels of cytosolic ferrous iron (Fe2+) and lipid peroxidation in end-stage diseased tissues compared with healthy controls. Using primary and immortalized cell cultures modeling the TCF4 intronic trinucleotide repeat expansion genotype, we found altered gene and protein expression involved in ferroptosis compared to controls including elevated levels of Fe2+, basal lipid peroxidation, and the ferroptosis-specific marker transferrin receptor 1. Increased cytosolic Fe2+ levels were detected after physiologically relevant doses of UVA exposure, indicating a role for ferroptosis in FECD disease progression. Cultured cells were more prone to ferroptosis induced by RSL3 and UVA than controls, indicating ferroptosis susceptibility is increased by both FECD genetic background and UVA. Finally, cell death was preventable after RSL3 induced ferroptosis using solubilized ubiquinol, indicating a role for anti-ferroptosis therapies in FECD. This investigation demonstrates that genetic background and UVA exposure contribute to iron-mediated lipid peroxidation and cell death in FECD, and provides the basis for future investigations of ferroptosis-mediated disease progression in FECD.

MitoQ relieves mitochondrial dysfunction in UVA and cigarette smoke-induced Fuchs endothelial corneal dystrophy

Fuchs endothelial corneal dystrophy (FECD), a degenerative corneal condition, is characterized by the droplet-like accumulation of the extracellular matrix, known as guttae and progressive loss of corneal endothelial cells ultimately leading to visual distortion and glare. FECD can be influenced by environmental stressors and genetic conditions. However, the role of mitochondrial dysfunction for advancing FECD pathogenesis is not yet fully studied. Therefore, in the present study we sought to determine whether a combination of environmental stressors (ultraviolet-A (UVA) light and cigarette smoke condensate (CSC)) can induce mitochondrial dysfunction leading to FECD. We also investigated if MitoQ, a water-soluble antioxidant, can target mitochondrial dysfunction induced by UVA and CSC in human corneal endothelial cells mitigating FECD pathogenesis. We modeled the FECD by increasing exogenous oxidative stress with CSC (0.2%), UVA (25J/cm2) and a combination of UVA + CSC and performed a temporal analysis of their cellular and mitochondrial effects on HCEnC-21T immortalized cells in vitro before and after MitoQ (0.05 μM) treatment. Interestingly, we observed that a combination of UVA + CSC exposure increased mitochondrial ROS and fragmentation leading to a lower mitochondrial membrane potential and increased levels of cytochrome c release leading to apoptosis and cell death. MitoQ intervention successfully mitigated these effects and restored cell viability. The UVA + CSC model could be used to study stress induced mitochondrial dysfunction. Additionally, MitoQ can serve as a viable antioxidant in attenuating mitochondrial dysfunction, underscoring its potential as a molecular-focused treatment approach to combat FECD pathogenesis.

Safety of intraoperative autologous plasma incubation of corneal grafts for reducing endothelial cell loss: a pilot study.

Corneal endothelial cell loss contributes to transplant failure. Autologous plasma products (APP) activate salvaging pathways that can prevent oxidative stress perioperatively. This study aimed to evaluate the safety of intraoperative incubation of full-thickness corneal grafts in platelet-rich plasma (aPRP) and plasma rich in growth factors (PRGF-Endoret) in mitigating postoperative corneal endothelial cell loss (ECL). Pilot study including patients undergoing penetrating keratoplasty (PK) for various indications between June 2021 and December 2022. Patients were randomly assigned to receive either aPRP or PRGF-Endoret incubation, while those who declined intervention served as the control group. Demographic and clinical data were collected, including preoperative and postoperative endothelial cell count, intraocular pressure, pachymetry, and adverse reactions. Thirty individuals who underwent PK completed follow-up: eight from the aPRP group, 10 from the PRGF-Endoret group, and 12 from the control group. No adverse events related to APP treatment were recorded. In the first and third postoperative months, the APP group had significantly lower ECL percentages (37% vs. 25%, p = 0.02, and 44% vs. 33%, p = 0.02, respectively); this trend was maintained in the sixth month. When stratified, the PRGF-Endoret group showed significant differences in ECL reduction compared to controls at both time points (p = 0.03 and p = 0.05, respectively). The aPRP group showed a similar statistically significant outcome exclusively on the third postoperative month (p = 0.04). APP tended to reduce corneal edema faster than controls. Hexagonality was significantly better in the APP groups in the first and third months, particularly in the PRGF-Endoret group (p < 0.005). Preoperative incubation with APP is safe and promotes better endothelial cell quality and quantity in the early postoperative period following PK. These findings suggest a potential clinical benefit in enhancing graft outcomes and warrant further investigation.

Trocar-assisted extraocular technique for intrascleral intraocular lens fixation using a 90°-curved forceps: a modified extraocular forceps-guided technique.

To investigate the surgical outcomes of intrascleral intraocular lens (IOL) fixation using a modified extraocular forceps-guided technique. Retrospective case series. Overall, 81 eyes of 78 patients who underwent intrascleral IOL fixation using the modified extraocular forceps-guided technique were included. The procedure entailed creating 2 scleral half-layer T-shaped incisions perpendicular to the main incision and forming a scleral tunnel. A 25-gauge trocar was inserted at the lower end of the T-shaped incision to perform vitrectomy. A 27-gauge needle was inserted from the left-hand port, and the leading haptic was inserted into the needle lumen. After removal of the right-hand trocar, a 90°-curved intrascleral fixation forceps was inserted into the eye, exposing the tip at the main incision, thus allowing the tip of the extraocular trailing haptic to be gripped and both haptics to be pulled out. The left-hand trocar was removed, and the haptics were buried in the scleral tunnel. The surgical outcomes of this technique were retrospectively evaluated on the basis of the medical records. The induction of haptics was successful in all cases. The preoperative best-corrected visual acuity improved from 0.35±0.68 to 0.12±0.36 logMAR postoperatively (P<0.01). The refractive error was -0.27±0.87 D; IOL decentration, 0.39±0.18 mm; IOL tilt, 5.97±2.65°; IOL astigmatism, 0.35±0.36 D; and corneal endothelial cell loss, 10.3±12.7%. There were no serious complications related to the surgical technique. The modified extraocular forceps-guided technique allows for safe and straightforward induction of the trailing haptics and enables the performance of intrascleral IOL fixation with minimal scleral incisions.

Comparison of corneal endothelial cell density reduction between primary open-angle glaucoma and pseudo-exfoliation glaucoma patients at 3years after Ex-Press® surgery.

We compared corneal endothelial cell (CED) loss after Ex-Press (EXP) surgery between patients with primary open-angle glaucoma (POAG) and pseudo-exfoliation glaucoma (PEX). This was a single-facility retrospective study. We included glaucoma patients who had undergone EXP surgery and were followed up > 3years. We measured the CED before and after (at 12, 24, and 36months) EXP surgery by noncontact specular microscopy and compared the means of the CED values and CED survival ratios after EXP surgery by paired t-test. We included 119 eyes that underwent EXP surgery, including 60 POAG eyes and 59 PEX eyes. In the POAG group, the mean CED decreased from 2389 ± 321 at baseline to 2230 ± 424 cells/mm2 after 3years. In the PEX group, the mean CED decreased from 2111 ± 510 at baseline to 1845 ± 628 cells/mm2 after 3years. At the 3-year follow-up, the CED survival ratio was 93.3 ± 12.5% in the POAG group and significantly lower, at 85.0 ± 19.5%, in the PEX group (p = 0.0064). Two cases in the PEX group developed bullous keratopathy. EXP surgery decreased the corneal endothelial cell populations in PEX patients faster than POAG patients.

A Prospective, Randomized, Controlled Clinical Investigation Comparing the Efficacy and Safety of Sodium Hyaluronate-Based Ophthalmical Viscosurgical Devices FIDIAL PLUS and IAL®-F in Cataract Surgery.

Purpose: To protect the corneal endothelium, various ophthalmical viscoelastic devices (OVDs) are used during cataract surgery. In this study, we compared two sodium hyaluronate-based OVD, the bacteria-derived FIDIAL PLUS OVD (test) with the animal-derived IAL®-F OVD (reference) during the surgical procedure. Methods: Fifty patients with bilateral cataract participated in the study: 50 eyes randomly received FIDIAL PLUS and 50 eyes received IAL®-F (ratio 1:1). Noninferior efficacy of FIDIAL PLUS compared with reference OVD (first objective) was evaluated using a paired t-test comparing the mean percent loss of corneal endothelial cells (CECs) with FIDIAL PLUS against the mean percent loss with IAL®-F. Corneal endothelial protection during cataract surgery with FIDIAL PLUS without significant (≥30 mmHg) postoperative intraocular pressure (IOP) increase (main secondary objective) was assessed using a repeated measures logistic model comparing the incidence of significant postoperative IOP elevation between the two groups. Safety, tolerability, and efficacy were also evaluated by assessing secondary endpoints before and after surgery. Results: FIDIAL PLUS showed a statistically noninferior efficacy compared with IAL®-F; there was no significant increase in IOP in either group or different trends of the secondary endpoints were observed between the OVD groups. The safety profile was similar in both OVD groups and no adverse device effects were reported. Conclusions: This study demonstrates the equivalent efficacy, tolerability, and safety of the bacteria-derived FIDIAL PLUS compared with the animal-derived IAL®-F, confirming the clinical value of this product.

Evaluation of endothelial cell loss after cataract surgery in patients with pseudoexfoliative syndrome

Introduction: Despite modern techniques and technologies for cataract surgery, pseudoexfoliative syndrome poses a challenge to surgeons due to weakness of the zonular apparatus and limited pupillary dilation. Quantitative and qualitative morphological changes in the corneal endothelium have been demonstrated by several studies. An accumulated risk of endothelial cell loss can be expected in these patients following more complicated and prolonged surgery, often requiring complex manipulation of the cataract, iris, and IOL. Our present work aims to compare the loss of endothelial cells after uncomplicated phacoemulsification in patients without and with pseudoexfoliative syndrome. Materials and methods: We conducted a prospective comparative study collected at the Rabat specialty hospital, spanning from August to December 2023. Were included in this study 60 candidates for cataract surgery: - 30 patients with pseudoexfoliation syndrome (PXF) and - 30 without capsular exfoliation (non-PXF) as a control group. We excluded from this work diabetic patients, glaucomatous patients, patients with a history of surgery, ocular trauma or uveitis, high myopia, patients with preoperative corneal abnormalities as well as all complicated cataract surgeries. All patients underwent cataract surgery by phacoemulsification with implantation. - 30 without capsular exfoliation (non-PXF) as a control group. We excluded from this work diabetic patients, glaucomatous patients, patients with a history of surgery, ocular trauma or uveitis, high myopia, patients with preoperative corneal abnormalities as well as all complicated cataract surgeries. All patients underwent cataract surgery by phacoemulsification with implantation. Discussion: In our series, we did not find a statistically significant difference in the density of preoperative endothelial cells between the 2 groups, this result is similar to that obtained by KALJURAND et al, on the other hand for ken hayashi et al, and wirbelauer et al, the difference between the 2 groups was statistically significant. Regarding postoperative cell loss, our results agreed with those obtained by Ken Hayashi et al, who also reported greater endothelial cell loss in the PXF group compared to the control, unlike Wirbelauer et al, for whom the loss of endothelial cells was similar between the 2 groups. In the study by Kaljurand et al, the average percentage loss was 18% in the PXF group versus 11.6 in the control group, this difference had a statistically low significance. Conclusion: The loss of corneal endothelial cells after phacoemulsification in eyes with capsular pseudoexfoliation was significantly greater than in eyes without PXF, these results suggest that corneal endothelial cells of patients with pseudoexfoliation syndrome are more vulnerable to cataract surgery than healthy endothelial cells. To prevent serious endothelial lesions, a precise preoperative evaluation of the corneal endothelial state by specular microscopy seems necessary in these patients, with more precision and precautions during the procedure.

Comparison of corneal endothelial cell loss in FLACS: impact on endothelial cells in different regions.

To compare changes in corneal endothelial parameters after femtosecond laser-assisted cataract surgery (FLACS) and conventional phacoemulsification surgery (CPS) in different corneal regions. Chang Gung Memorial Hospital, Linkou, Taiwan. Single-center, retrospective. Before and 1, 3, and 6 months postoperatively, specular microscopy was performed to measure endothelial cell density (ECD), corneal thickness, hexagonal cell rate (Hex), and coefficient of variation (CoV). Position 1 referred to the central cornea, position 2 was nearest to the main wound, and position 3 was at the peripheral zone diagonal to the main wound. This study analyzed 96 eyes in the FLACS group and 110 eyes in the CPS group. Preoperatively, position 1 had lower ECD and CoV and higher Hex compared with the peripheral regions. FLACS patients had a significantly less phacoemulsification time and cumulative dissipated energy. At 1 month, FLACS patients showed a significantly smaller increase in corneal thickness at positions 1 and 2. At 3 months, FLACS patients had lower endothelial cell loss (ECL) at positions 1 and 3. ECL remained lower in FLACS patients at 6 months. The highest ECL was observed at position 2 in both groups and was progressive up to 6 months. After phacoemulsification, ECL varied in different corneal regions. At 3 months, the FLACS group exhibited significantly less ECL at the central cornea; however, the continued ECL at 6 months near the main wound suggested ongoing endothelial remodeling in the region.

Causes and outcomes of implantable collamer lens explantation in patients with corneal endothelial cell loss.

To investigate the correlated factors of corneal endothelial cell density (ECD) loss and ECD change in implantable collamer lens (ICL) explantation patients. Seoul St. Mary's Hospital, Seoul, South Korea. Retrospective analysis. The study cohort consisted of 93 eyes from 50 patients who underwent ICL explantation. Correlation analysis was performed to assess the ocular parameters associated with ECD loss, while percentage of ECD change (ΔECD%) was monitored up to 6 months postoperatively. Receiver operating characteristic (ROC) curve was used to set cutoff values of ocular parameters to prevent ECD loss after explantation. In multiple regression analysis, high vaulting, high vaulting/anterior chamber depth (ACD), low anterior chamber angle (ACA), and high iris pigmentations are the significant factors of ECD loss. At postoperative 6 months, 14 eyes (15.1%) had decrease (10.5% loss), 47 eyes (51.0%) were stationary, and 32 eyes (34.4%) had increase (12.7% gain) of ECD. The ROC curve analysis showed that vaulting had the highest area under the curve (AUC = 0.822), followed by vaulting/ACD (AUC = 0.821), ECD (AUC = 0.753), and ACA (AUC = 0.723) (all P < .01). Preoperative ECD showed a sensitivity of 77.6% and specificity of 86.7% in preventing ECD loss after explantation, with a cutoff value of 1722 cells/mm 2 , as determined by ROC curve analysis. Our study demonstrated that high vaulting is a significant factor in ECD loss among ICL-inserted patients. To prevent continuous ECD loss in ICL patients, close monitoring of ECD and making appropriate decisions regarding explantation may be necessary.

Corneal endothelial changes seven years after phacoemulsification cataract surgery

PurposeTo evaluate long-term postoperative corneal changes after phacoemulsification cataract surgery.MethodsTwenty patients who participated in a previous study regarding corneal endothelial changes after phacoemulsification cataract surgery were examined after 7 years. The patients were divided in three groups based on their initial increase in central corneal thickness day one after the surgery: < 5% increase, 6–20% increase and ≥ 20% increase. The primary outcome measures were corneal endothelial cell loss (ECL), endothelial cell count (ECC) and endothelial morphology.ResultsAfter 7 years, a difference in cell loss between the groups was observed, except for groups 1 and 2. Endothelial cell count (ECC) differed significantly between groups 1 and 3 at 3 months. At 7 years, there was no difference in ECC between the three groups. Cell loss was found exclusively in group 1 between 3 months and 7 years. Endothelial cell morphology showed a converging pattern between 3 months and 7 years.ConclusionAfter phacoemulsification cataract surgery, long-term ECC and morphology appear to converge towards a comparable steady state regardless of initial corneal swelling and endothelial cell loss.

Characterization of a Novel Mouse Model for Fuchs Endothelial Corneal Dystrophy.

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

Enhanced Surgical Safety through Protective Penetrating Keratoplasty: A Retrospective Analysis of 22 Cases.

To assess the surgical safety, postoperative outcomes, and the impact of PPK on corneal endothelial cell density through a retrospective analysis of 22 cases. Settings and Design. A retrospective cross-sectional observational study was executed at Hermanos Ameijeiras Hospital from February 2018 to December 2021, involving 22 patients (22 eyes) who were unresponsive to other medical treatments and had a corrected distance visual acuity of ≤0.1. Patients underwent PPK, with surgical procedures and postoperative care documented. Statistical analysis was performed on qualitative and quantitative variables to evaluate the surgical outcomes and the corneal endothelial cell density changes postoperation. All surgeries demonstrated a significant improvement in postoperative visual acuity (p ≤ 0.001) and recorded a 9.2% decrease in the corneal endothelial cell density at 12 months. Noteworthy complications included one case of intraoperatively discovered haptic dislocation and one postoperative bacterial keratitis. PPK could potentially mitigate perioperative complications, ensure graft clarity, and reduce corneal endothelial cell loss, presenting itself as a viable alternative to traditional PK. Although the results are encouraging, larger-scale studies are essential to validate the benefits and applicability of PPK in broader clinical settings.

Narrative review after post-hoc trial analysis of factors that predict corneal endothelial cell loss after phacoemulsification: Tips for improving cataract surgery research.

Identifying pre/perioperative factors that predict corneal endothelial-cell loss (ECL) after phacoemulsification may reveal ways to reduce ECL. Our literature analysis showed that 37 studies have investigated one or several such factors but all have significant limitations. Therefore, the data of a large randomized controlled trial (PERCEPOLIS) were subjected to post-hoc multivariate analysis determining the ability of nine pre/perioperative variables to predict ECL. PERCEPOLIS was conducted in 2015-2016 to compare two phacoemulsification techniques (subluxation and divide-and-conquer) in terms of 3-month ECL. Non-inferiority between the techniques was found. In the present study, post-hoc univariate and multivariate analyses were conducted to determine associations between ECL and age, sex, cataract density, preoperative endothelial-cell density, phacoemulsification technique, effective phaco time (EPT), and 2-hour central-corneal thickness. The data are presented in the context of a narrative review of the literature. Three-month data were available for 275 patients (94% of the randomized cohort; mean age, 74 years; 58% women). Mean LOCSIII cataract grade was 3.2. Mean EPT was 6 seconds. Mean ECL was 13%. Only an older age (beta = 0.2%, p = 0.049) and higher EPT (beta = 1.2%, p = 0.0002) predicted 3-month ECL. Cataract density was significant on univariate (p = 0.04) but not multivariate analysis. The other variables did not associate with ECL. Older age may amplify ECL due to increased endothelial cell fragility. EPT may promote ECL via cataract density-dependent and -independent mechanisms that should be considered in future phacoemulsification research aiming to reduce ECL. Our literature analysis showed that the average ECL for relatively unselected consecutively-sampled cohorts is 12%.