Corneal Endothelial Cell Loss Research Articles

Comparison of Corneal Endothelial Cell Loss in Femtosecond Laser-assisted Cataract Surgery: Impact on Endothelial Cells in Different Regions.

To compare changes in corneal endothelial parameters following femtosecond laser-assisted cataract surgery (FLACS) and conventional phacoemulsification (CPS) in different corneal regions. Chang Gung Memorial Hospital, Linkou, Taiwan, 2018- 2022. Single-center, retrospective. Before and 1, 3, and 6 months post-op, 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 to the peripheral regions. FLACS patients had a significantly less phaco time and cumulative dissipated energy. At one 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. Following phacoemulcification, 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%.

Unexpected findings: loss of corneal endothelial cells in Uygur patients with exfoliation syndrome

PurposeThis study aimed to investigate anterior segment parameters in patients with exfoliation syndrome (XFS) and exfoliation glaucoma (XFG).MethodsThe study adopted a retrospective case series design, involving a total of 56 patients (112 eyes) with unrelated XFS/XFG (XFS: 26 patients/60 eyes; XFG: 30 patients/44 eyes) and 100 age-related cataract cases as the control group (200 eyes). The participants were evaluated at the ophthalmology department of the First Affiliated Hospital of Xinjiang Medical University. Clinical data, including eye axial length, anterior chamber depth, white-to-white distance, central corneal thickness, and corneal endothelial cell density (ECD), were collected for statistical analysis.ResultsECD exhibited a significant difference between the XFS/XFG and age-related cataract groups (P < 0.001), while the remaining indexes did not show statistical differences (P > 0.05). Ocular parameters in patients with XFS and XFG were distinct from those in age-related cataract cases, with consistent results. Notably, there were no statistically significant differences between XFS and XFG patients.ConclusionsECD is reduced in XFS/XFG patients compared with age-related cataract subjects. It is crucial to remain vigilant to enhance surgical safety in XFS/XFG patients and prevent complications proactively.

Fuchs endothelial corneal dystrophy: an updated review.

The present review will summarize FECD-associated genes and pathophysiology, diagnosis, current therapeutic approaches, and future treatment perspectives. Literature review. Fuchs' endothelial corneal dystrophy (FECD) is the most common bilateral corneal dystrophy and accounts for one-third of all corneal transplants performed in the US. FECD is caused by a combination of genetic and non-heritable factors, and there are two types: early-onset FECD, which affects individuals from an early age and is usually more severe, and late-onset FECD, which is more common and typically manifests around the age of 40. The hallmark findings of FECD include progressive loss of corneal endothelial cells and the formation of focal excrescences (guttae) on the Descemet membrane. These pathophysiological changes result in progressive endothelial dysfunction, leading to a decrease in visual acuity and blindness in later stages. The present review will summarize FECD-associated genes and pathophysiology, diagnosis, current therapeutic approaches, and future treatment perspectives. With the characterization and understanding of FECD-related genes and ongoing research into regenerative therapies for corneal endothelium, we can hope to see more significant improvements in the future in the management and care of the disease.

Оценка клинической эффективности нового способа адаптивного управления инфузией при факоэмульсификации

Reduction of the adverse effects of intraoperative intraocular pressure fluctuation referred to as post-occlusion surge on the intraocular structures is an important task for ensuring phacoemulsification safety. In this regard, the method to control infusion during phacoemulsification based on controlling the infusion and aspiration flow rates in combination with monitoring of vacuum parameters was developed. The study was aimed to provide comparative assessment of clinical and functional characteristics of the eye in patients after phacoemulsification using the new and already existing adaptive infusion control methods. A total of 38 patients aged 66.4 ± 7.8 years (15 males and 23 females) in the index group (Optimed Profi system with the use of new method) and 35 patients aged 68.7 ± 7.5 years (16 males and 19 females) in the control group (Centurion Vision System with Active Fluidics) underwent surgery due to cataract. The patients underwent comprehensive eye examination before surgery and on days 1, 7, 30, months 3, 6 after surgery. The smaller loss of corneal endothelial cells on months 3 and 6 after surgery was observed in patients of the index group with grade III and IV cataract (p &lt; 0.05). Comparison of macular microcirculation parameters revealed the reduced FAZ area by month 6 of postoperative follow-up in the index group, along with the increased total vascular density of the deep vasculature (p &lt; 0.001). A significant decrease in the total density of the superficial and deep vascular plexuses by month 6 of postoperative follow-up was observed in the control group (p &lt; 0.05). The use of new adaptive infusion control method contributes to effective phacoemulsification of cataracts of varying density with the lower percentage of the corneal endothelial cells lost in the late postoperative period.

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

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. Prospective cohort study. 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. 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). 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.

Investigation of the functional impact of CHED- and FECD4-associated SLC4A11 mutations in human corneal endothelial cells.

Mutations in the solute linked carrier family 4 member 11 (SLC4A11) gene are associated with congenital hereditary endothelial dystrophy (CHED) and Fuchs corneal endothelial dystrophy type 4 (FECD4), both characterized by corneal endothelial cell (CEnC) dysfunction and/or cell loss leading to corneal edema and visual impairment. In this study, we characterize the impact of CHED-/FECD4-associated SLC4A11 mutations on CEnC function and SLC4A11 protein localization by generating and comparing human CEnC (hCEnC) lines expressing wild type SLC4A11 (SLC4A11WT) or mutant SLC4A11 harboring CHED-/FECD4-associated SLC4A11 mutations (SLC4A11MU). SLC4A11WT and SLC4A11MU hCEnC lines were generated to express either SLC4A11 variant 2 (V2WT and V2MU) or variant 3 (V3WT and V3MU), the two major variants expressed in ex vivo hCEnC. Functional assays were performed to assess cell barrier, proliferation, viability, migration, and NH3-induced membrane conductance. We demonstrate SLC4A11-/- and SLC4A11MU hCEnC lines exhibited increased migration rates, altered proliferation and decreased cell viability compared to SLC4A11WT hCEnC. Additionally, SLC4A11-/- hCEnC demonstrated decreased cell-substrate adhesion and membrane capacitances compared to SLC4A11WT hCEnC. Induction with 10mM NH4Cl led SLC4A11WT hCEnC to depolarize; conversely, SLC4A11-/- hCEnC hyperpolarized and the majority of SLC4A11MU hCEnC either hyperpolarized or had minimal membrane potential changes following NH4Cl induction. Immunostaining of primary hCEnC and SLC4A11WT hCEnC lines for SLC4A11 demonstrated predominately plasma membrane staining with poor or partial colocalization with mitochondrial marker COX4 within a subset of punctate subcellular structures. Overall, our findings suggest CHED-associated SLC4A11 mutations likely lead to hCEnC dysfunction, and ultimately CHED, by interfering with cell migration, proliferation, viability, membrane conductance, barrier function, and/or cell surface localization of the SLC4A11 protein in hCEnC. Additionally, based on their similar subcellular localization and exhibiting similar cell functional profiles, protein isoforms encoded by SLC4A11 variant 2 and variant 3 likely have highly overlapping functional roles in hCEnC.

Influence of the pattern of femtosecond laser-assisted lens nucleus fragmentation on the energy and hydrodynamic parameters of phacoemulsification

This study evaluates the influence of various patterns of preliminary femtosecond laser-assisted fragmentation of the lens nucleus on the energy, hydrodynamic parameters of phacoemulsification, and the degree of corneal endothelial cell loss. Hybrid phacoemulsification was performed in 336 patients (336 eyes) with grade IV immature cataract according to the Buratto classification in three age-matched groups. Group 1 included 103 patients (103 eyes) who underwent hybrid phacoemulsification with preliminary femtosecond laser-assisted fragmentation of the nucleus with a «pizza» pattern (division of the nucleus with 10 radial cuts). Group 2 included 112 patients (112 eyes) who underwent femtosecond laser-assisted fragmentation of the nucleus with a «cylinders» pattern (division of the nucleus with 8 radial cuts in combination with 5 circular cuts). Group 3 included 121 patients (121 eyes) who underwent femtosecond laser-assisted fragmentation of the nucleus with a «grid» pattern (division of the nucleus with 8 radial cuts in combination with multiple mutually perpendicular cuts in the central zone in the form of a grid with a 0.5 mm cell). Effective ultrasound time and the volume of irrigation solution for emulsification of the lens nucleus fragments were determined during the operation. The loss of corneal endothelial cells was assessed 3 months after surgery. The minimum effective ultrasound time was noted after using the "grid" pattern - 4.05 (2.88; 4.74) s, which was significantly less than with the "cylinders" pattern - 4.97 (3.78; 5.88) s and the "pizza" pattern - 6.15 (4.52; 7.75) s (p<0.05). The effective ultrasound time when using the "cylinders" pattern was significantly less than with the "pizza" pattern (p<0.05). The volume of irrigation solution used for emulsification of the lens nucleus fragments was significantly less in the "grid" pattern - 41.5 (33.5; 49.5) ml compared to the "cylinders" patterns 58.5 (51.0; 66.0), p<0.05 and "pizza" pattern 75.0 (66.0; 83.5), p<0.01. The volume of irrigation solution when using the "cylinders" pattern was significantly less than when using the "pizza" pattern (p<0.05). The loss of corneal endothelial cells after using the "grid" pattern was 8.82 (7.59; 9.87)%, which was significantly less than after the "cylinders" patterns - 9.97 (8.81; 10.83)%, p<0.05 and "pizza" - 11.70 (10.62; 12.97)%, p<0.05. At the same time, the loss of endothelial cells after using the "cylinders" pattern was significantly less than after the "pizza" pattern (p<0.05). The choice of the optimal pattern of preliminary femtosecond laser-assisted fragmentation of the lens nucleus provides a significant decrease in the energy and hydrodynamic parameters of phacoemulsification and, accordingly, the loss of corneal endothelial cells.

Comparison of Corneal Endothelial Cell Loss during Manual Small-incision Cataract Surgery using Visco-expression versus Irrigating Wire Vectis-assisted Nucleus Removal: A Prospective Randomised Study

Introduction: Age-related cataract is the leading cause of curable blindness in India, and Manual Small-Incision Cataract Surgery (MSICS) is a machine-independent and cost-effective alternative to phacoemulsification for handling this significant burden. In every cataract surgery, some endothelial cell loss is inevitable. Therefore, the present study was conducted to compare endothelial cell loss in the two most commonly practiced methods of nucleus delivery in MSICS. Aim: To compare and analyse endothelial cell loss during MSICS using viscoelastic/viscoexpression-assisted nucleus removal versus irrigating wire vectis-assisted nucleus removal. Materials and Methods: A prospective randomised interventional study was conducted at the Regional Institute of Ophthalmology, Postgraduate Institute of Medical Sciences (PGIMS) Rohtak, Haryana, India. The study duration was three years, from May 2018 to May 2021. A total of 250 patients with uncomplicated senile cataract over 40 years of age, with nuclear sclerosis of grade 2 or higher and “with the rule” astigmatism, were included in the study. The patients were randomly divided into Group A and Group B (125 each), who underwent MSICS using visco-expression (Group A) versus irrigating wire vectis-assisted (Group B) nucleus removal. Visual Acuity (VA), keratometry, astigmatism, pachymetry, and Endothelial Cell Density (ECD) were recorded in every patient preoperatively and postoperatively on day 1 and day 40. The Shapiro-wilk test was used to assess the normality of the data, and student’s t-test was performed to identify significant differences in continuous factors between the two groups. Chi-square test was used to find the association between factors and techniques, with a p-value &lt;0.05 considered statistically significant. Results: The mean age of the patients was 68.5±9.4 years (range 52-89 years) with a significant male preponderance. The mean LogMAR visual acuity on Postoperative Day (POD)-1 was 0.3±0.1 for Group A, while for Group B, it was 0.5±0.2, showing a statistically significant difference (p=0.004). However, on day 40, visual acuity was comparable in both groups, with Group A (0.1±0.2) and Group B (0.1±0.1), and no significant difference (p=0.09). On POD-1, the percentage change in Endothelial Cell Density (ECD) was 4.2% in Group A and 10.6% in Group B, with a statistically significant difference (p=0.0017). On day 40, it was 2.1% and 4.8% in Group A and Group B, respectively, also showing a statistically significant difference (p=0.003). On postoperative day 40, the mean Surgically Induced Astigmatism (SIA) in Group A and Group B was 0.67±0.24 and 0.74±0.41, respectively, but this difference was statistically insignificant (p=0.074). Intra and postoperative complications such as hyphema, iridodialysis, and corneal oedema were more common in Group B than Group A. Conclusion: The study concludes that there was a statistically significant endothelial cell loss in the irrigating wire vectisassisted nucleus delivery method compared to the viscoexpression of the nucleus during MSICS. The present method also showed delayed visual rehabilitation and a higher risk of intra and postoperative complications. Therefore, viscoexpression of the nucleus should be the preferred method of nucleus delivery in every MSICS where feasible.

Risk factors for corneal endothelial cell loss after phacoemulsification.

The purpose of this study was to evaluate the changes in corneal endothelial cell density (CECD) occurring after cataract phacoemulsification surgery and identify factors associated with cell loss. This was a retrospective study involving patients who underwent cataract phacoemulsification surgery between January 1, 2018, and December 31, 2018, at two private hospitals. Demographic data and biometric parameters were obtained preoperatively. Ultrasound metrics were recorded for each operation, including total on time (TOT), total equivalent power in position 3, and cumulative dissipated energy (CDE). Using corneal specular microscopy, CECD was measured preoperatively and postoperatively at 12, 24, and 36 months. Factors associated with decreased CECD were identified. This study included 223 eyes of 133 patients. The mean CECD was 2530.03 ± 285.42 cells/mm2 preoperatively and significantly decreased to 2364.22 ± 386.98 cells/mm2 at 12 months (P < 0.001), 2292.32 ± 319.72 cells/mm2 at 24 months (P < 0.001), and 2242.85 ± 363.65 cells/mm2 at 36 months (P < 0.001). The amount of cell loss was associated with age, gender, preoperative CECD, preoperative anterior chamber depth, lens thickness, TOT, and CDE. Using multivariate analysis, age, preoperative CECD, and TOT were identified as independent predictors for CECD loss 12 months after surgery. The greatest decrease in CECD occurred during the first year after cataract surgery, and the amount of cell loss was influenced by both baseline patient characteristics and ultrasound metrics. Longer-term prospective studies in a larger cohort may yield more information.

Assessment of safety profile of phacoemulsification in hard cataract

Purpose: The aim of the study was to assess safety of phacoemulsification in hard cataract by evaluating the post-operative endothelial cell loss and visual acuity. Materials and Methods: This is a hospital-based, prospective study conducted on 70 eyes of 70 patients with hard cataract. At the time of admission, detailed evaluation of anterior segment using slit lamp bio microscopy was done and cataract graded using LOCS III. Posterior segment was evaluated using indirect ophthalmoscopy under 20D/B-Scan. All patients with hard cataract underwent phacoemulsification procedure. The visual acuity and endothelial cell density assessed using Snellens chart and specular microscopy pre-operatively and post-operatively on Day 1, Day 7, and Day 30, respectively. Descriptive statistics, namely, mean, standard deviation to express continuous variables wherever applicable. Correlation between endothelial cell loss and cataract grading and correlation between final endothelial cell loss and final best-corrected visual acuity (BCVA) is analyzed by using Pearson’s Chi-square test and Pearson’s correlation coefficient. P value &lt;0.05 is considered as statistically significant. Results: Among 70 eyes, 40 (57.1%) had NO4-NC4, 18 (25.70%) had NO5-NC5, and 12 (17.1%) had NO6-NC6 cataract grading. The endothelial cell loss was 4.28%, 6.19%, and 7.15% on post-operative day 1, 7, and 30, respectively. There was a positive correlation showing that, as the cataract grading increased the endothelial cell loss increased too. The BCVA of 6/9 was achieved in 2 (2.8%), 6/6 in 68 (97.2%) at the end of four weeks. Conclusion: Although density of cataract has unfavorable influence on early post-operative corneal endothelial cell loss, it did not significantly influence final BCVA. The technique of phacoemulsification for hard nuclear cataract is worthy to be spread due to safety, effectiveness with good visual outcomes.

Comparison of keratoplasty outcomes at the scar versus edema stages of keratoconus.

To assess the outcomes of deep anterior lamellar keratoplasty or penetrating keratoplasty at the scar and the edema stages. Forty-five patients (45 eyes) with keratoconus scar stage (scar group, n=26; penetrating keratoplasty a subgroup, n=7; deep anterior lamellar keratoplasty b subgroup, n=19) and keratoconus edema stage (edema group, n=19; penetrating keratoplasty c subgroup, n=12; deep anterior lamellar keratoplasty d group, n=7) who received penetrating keratoplasty or deep anterior lamellar keratoplasty from 2000 to 2022 were retrospectively studied. At 1, 6, and 12 months after surgery, the best-corrected visual acuity, astigmatism, spherical equivalent, corneal endothelial cell density, and complications were analyzed. The best-corrected visual acuity and average corneal endothelial cell loss rate were not significantly different between the scar and edema groups (p>0.05). At 6 and 12 months after surgery, the astigmatism and spherical equivalent in the scar group were significantly lower than those in the edema group (p<0.05). The spherical equivalent of the deep anterior lamellar keratoplasty b subgroup was lower than that of the penetrating keratoplasty a subgroup in the scar group 6 months after surgery (p<0.05). In the edema group, there was no significant difference in spherical equivalent between subgroups (p>0.05). There were no significant differences in best-corrected visual acuity and astigmatism between subgroups within the two groups (p>0.05). In comparison to the scar group, the edema group experienced more complications. According to a survival analysis, there was no statistically significant difference between the scar group and the edema group regarding the progression of vision. In terms of the outcomes and prognosis for vision after keratoplasty with edema stage and scar stage, deep anterior lamellar keratoplasty may be as effective as penetrating keratoplasty.

Трансплантация суспензии эндотелиальных клеток в эксперименте ex vivo

Relevance. Corneal transplantation with entire cornea or anormal layers replacement remains the only treatment option for patients with corneal endothelium pathology. Selective endothelial replacement was introduced into practice two decades ago, namely posterior lamellar keratoplasty, which has advantages over penetrating keratoplasty. Improvements of this method led to technique creation where isolated Descemet's membrane with endothelium monolayer without stromal layer is transplanted. This technology is associated with risks of intra- and postoperative complications, and is difficult to perform. Nowadays, development is in progress of introducing corneal endothelial cells (CECs) transplantation without stromal layer and even without Descemet's membrane. CECs transplantation in suspension form has potential to change treatment approach of corneal endothelium pathologies giving possibility of rapid eyesight recovery and reducing need for graft material. Purpose. To evaluate effectiveness of corneal CECs suspension transplantation on cadaver eye in ex vivo experiment. Material and methods. CECs suspension was obtained by modified enzymatic method. CECs transplantation experiment consisted of 3 stages. Firstly, CECs loss was calculated depending on cell administration method. Secondly, corneoscleral button was used as recipient for the obtained suspension. The third stage was carried out on cadaver eyeball. Results. The viability of transplanted CECs and their effective adhesion to Descemet's membrane was confirmed in this experiment. The characteristic markers of CECs ZO-1, Na+/K+ -ATPase, Ki67 were determined in corneal samples by immunohistochemistry assay and single cells expressing Vimentin were detected after one-week cultivation. Conclusion. Based on transplantation experiment results, it can be noted this technique is quite promising in surgical rehabilitation of patients with corneal endothelial dysfunction. Thus, it seems relevant to continue research to achieve the main goal – to fully cover the defect of central zone of corneal posterior surface with isolated CECs given that their morphology and functional activity are preserved. Key words: cornea, endothelial corneal dystrophy, endothelial cell suspension, corneal endothelial cell transplantation

Sulcus Tube Internal Needle Guidewire Technique for Glaucoma Drainage Device Placement: Improving Surgical Ease and Precision.

Despite the rise of micro-invasive glaucoma surgery(MIGS), glaucoma drainage device implantation continues to be a mainstay among glaucoma surgical treatment options. Anterior chamber tube placement, while effective in reducing intraocular pressure(IOP), poses corneal endothelial risks. Ciliary sulcus tube placement shows promise in reduced corneal endothelial cell loss, but proper sulcus placement can be challenging. Our study describes the initialsafety and effectiveness results using a novel sulcus tube internal needle guidewire (STING) technique for glaucoma drainage device insertion into the ciliary sulcus. We retrospectively reviewed the charts of all consecutive patients who underwent the STING technique using the Ahmed ClearPath, Ahmed Glaucoma Valve, or Baerveldt glaucoma implant with at least 6 months of follow-up. Demographic characteristics, type of glaucoma, previous medical and surgical treatment, pre- and postoperative IOP, pre- and postoperative medications, complications, and success rates were recorded. Out of nine eyes, seven resulted in qualified success (77.8%). Preoperative mean IOP was 23.8 ± 6.3 mmHg, and postoperative IOP decreased significantly to 14.9 ± 3.7 mmHg (p = 0.008). The average number of preoperative medications per patient was 4.4 ± 0.7, while the average number of postoperative medications per patient was reduced significantlyto 3.6 ± 1.0 (p = 0.039). The STING technique is a novelmethod for placing a glaucoma drainage device into the ciliary sulcus, leading to IOP lowering with minimal complications. The STING technique is designed to improve surgical ease and increase anatomical precision of sulcus tube placement. Video available for this article.

Estrogen genotoxicity causes preferential development of Fuchs endothelial corneal dystrophy in females

Fuchs endothelial corneal dystrophy (FECD) is a genetically complex, age-related, female-predominant disorder characterized by loss of post-mitotic corneal endothelial cells (CEnCs). Ultraviolet-A (UVA) light has been shown to recapitulate the morphological and molecular changes seen in FECD to a greater extent in females than males, by triggering CYP1B1 upregulation in females. Herein, we investigated the mechanism of greater CEnC susceptibility to UVA in females by studying estrogen metabolism in response to UVA in the cornea. Loss of NAD(P)H quinone oxidoreductase 1 (NQO1) resulted in increased production of estrogen metabolites and mitochondrial-DNA adducts, with a higher CEnC loss in Nqo1−/− female compared to wild-type male and female mice. The CYP1B1 inhibitors, trans-2,3′,4,5′-tetramethoxystilbene (TMS) and berberine, rescued CEnC loss. Injection of wild-type male mice with estrogen (E2; 17β-estradiol) increased CEnC loss, followed by increased production of estrogen metabolites and mitochondrial DNA (mtDNA) damage, not seen in E2-treated Cyp1b1−/−male mice. This study demonstrates that the endo-degenerative phenotype is driven by estrogen metabolite-dependent CEnC loss that is exacerbated in the absence of NQO1; thus, explaining the mechanism accounting for the higher incidence of FECD in females. The mitigation of estrogen-adduct production by CYP1B1 inhibitors could serve as a novel therapeutic strategy for FECD.

Corneal Clarity after Phacoemulsification: Nuclear Management by Stop and Chop Method

Introduction: Restoration of effective vision is the principal aim of all modalities of cataract surgery including phacoemulsification. In this method, nuclear part of the cataractous lens is emulsified by ultrasonic power. Energy level of ultrasonic power and turbulence of fluid in the anterior chamber play an important role in corneal endothelial cell loss which inturn influences post-operative corneal clarity. Endothelial cell loss can be minimized by modification of nuclear management method. The common nuclear division techniques of phacoemulsification are stop and chop, divide and conquer and phaco chop. Purpose: To show post-operative corneal clarity after phacoemulsification by stop and chop technique of nuclear divisions. Materials and Methods: This prospective observational study was conducted at selected outdoor patients from January, 2023 to June, 2023 over 33 patients of age related cataract selected for phacoemulsification surgery. Patients were selected based on specific selection criteria. Selected patient underwent detail, ocular and systemic examinations as well as relevant investigations which included assessment of corneal endothelial cell count and central corneal thickness. Phacoemulsification were done in all patients by a single expert surgeon where technique of nuclear management by stop and chop were chosen randomly. Patients were followed up on 1 week, 4 weak and 12 weak after surgery. Corneal endothelial cell count and central corneal thickness were assessed in each visit. All the relevant data were presented by appropriate tables. Results: The mean age of the study subjects were 60.96 with standard deviation 1.75 years out of which 14 were males and 17 were females. Pre-operative value of mean endothelial cell count was 2620+-70.20/mm2. Mean value of endothelial count was 2420+-68.90/ mm2, 2345+-66.64/ mm2, 2310+-66.04/ mm2 respectively after 1 week , 4 weeks and 12 weeks after surgery. Mean value of central corneal thickness was 545+-40.50 micrometer, 535+-40.02 micrometer, 532+-39.85 micrometer respectively after 1 week, 4 weeks and 12 weeks after surgery. Conclusion: Quantitative assessment of endothelial cell count and central corneal thickness shows that at end of the study there was no significant difference in mean endothelial cell count and mean central corneal thickness . Medicine Today 2023 Vol.35(2): 118-120