Lower Endothelial Cell Density Research Articles

Corneal Endothelial Changes in Chinese Patients with Fuchs’ Uveitis Syndrome

ABSTRACT Purpose To analyze the changes of corneal endothelial cells in Chinese patients with unilateral Fuchs’ uveitis syndrome (FUS) and investigate the factors relevant to these changes. Methods Bilateral specular microscopic examination was performed in 459 Chinese patients with unilateral FUS from April 2008 to April 2023. The affected eyes constituted the study group, while the contralateral eyes served as controls. Results The median values of endothelial cell density (ECD), cell count, total cell size, and hexagonality were significantly lower in the FUS eyes compared to the control eyes (p < 0.001). The median values of average cell size, maximum cell size, SD of cell size, and CV were significantly higher in the FUS eyes compared to the control eyes (p < 0.001). Central ECD showed a negative correlation with age (r = −0.339; p < 0.001), maximum IOP (r = −0.127; p = 0.006), and the interval since symptom onset (r = −0.172; p < 0.001). The ECD was lower in eyes with ocular hypertension compared to those without ocular hypertension (p < 0.001). Eyes with KPs distributed on the central corneal endothelium had a significantly lower ECD than those with KPs distributed diffusely or KPs distributed triangularly on the inferior corneal endothelium (p = 0.006). Conclusion Our findings suggest decreased ECD, increased cell size, and morphological alterations in the affected eyes of Chinese patients with FUS. The reduction in ECD is correlated with age, elevated IOP, the interval since symptom onset, and the distribution of KPs.

Outcomes of retropupillary iris claw lens implantation in patients with intraocular lens dislocation and low (less than 1000 cells/mm2) corneal endothelial cell density

BackgroundPosterior chamber intraocular lens (IOL) dislocation is a common complication of cataract surgery. Dislocated IOLs often require surgical intervention due to the potentially severe risks of leaving this condition untreated. If a patient with extremely low corneal endothelial cell density (ECD) presents with IOL dislocation, the surgeon faces a crucial dilemma of choosing the most optimal surgical treatment option. We sought to investigate the efficacy and safety of retropupillary iris claw intraocular lens (R-IOL) implantation in patients with IOL dislocation and extremely low (< 1000 cells/mm2) ECD.MethodsWe retrospectively reviewed the medical records of nine patients (all men) whose pre-operative ECD was < 1000 cells/mm2 and who underwent R-IOL implantation due to intraocular subluxation or total dislocation into the vitreous cavity between 2014 and 2020. We evaluated corneal endothelial function and visual outcomes after surgery.ResultsNine patients were included in this study. The mean age at diagnosis was 64.89 ± 7.15 years (range 57–76 years), and the follow-up duration was 37.93 ± 23.72 months (range 18.07–89.07 months). No patients developed bullous keratopathy during follow-up. Compared to the initial ECD, corneal thickness (CT), coefficient variation of cell area (CV) and percentage of hexagonal cells (HEX), there was no statistically significant decrease in the ECD, CV, and HEX at last follow-up (P = 0.944, 0.778, 0.445, 0.443). There was significant improvement in the mean uncorrected distance visual acuity (UDVA) at the last follow-up (average 0.13 logMAR, 20/27 Snellen) compared to the pre-operative mean UDVA (average 1.09 logMAR, 20/250 Snellen) (P < 0.01).ConclusionsR-IOL implantation did not result in a statistically significant decline in corneal endothelial function in patients with preoperatively low ECD, and it significantly improved the mean UDVA postoperatively. R-IOL implantation appears to be a safe and effective treatment modality for intraocular lens dislocation in patients with low ECD (< 1000 cells/mm²); however, long-term follow-up studies are warranted to corroborate these findings.

In-vivo confocal microscopy predicts cytomegalovirus as the cause of chronic or recurrent anterior uveitis among Chinese.

To evaluate and compare endothelial features by in-vivo confocal microscopy (IVCM) in Chinese eyes with chronic or recurrent anterior uveitis (AU) with and without cytomegalovirus (CMV). A double-masked, cross-sectional case-control study at a tertiary eye clinic. Thirty eyes of 30 subjects were analyzed. Fifteen eyes (50%) were CMV positive, while fifteen eyes were negative for herpes simplex virus, varicella zoster virus and CMV. Absence of pseudoguttata was the strongest, independent risk factor for CMV (OR 34.53, 95% CI: 1.84-648.02, p = 0.018), followed by severe iris depigmentation (OR 31.45, 1.02-965.81, p = 0.048) and low corneal endothelial cell density (ECD) (OR 14.79, 1.14-191.30, p = 0.039) on univariable regression. All three remained statistically significant after adjustment. The combination of absence of pseudoguttata and low ECD on IVCM achieved a similar predictive value as iris depigmentation examination. Absence of pseudoguttata on IVCM was an independent predictor of positive CMV detection after adjusting for iris depigmentation and corneal endothelial cell density. The addition of this feature to severe iris depigmentation and low corneal ECD can increase the positive predictive value of detecting CMV. IVCM was a useful non-invasive tool to predict CMV in patients with chronic or recurrent AU.

A Case of Irreversible Corneal Endothelial Damage Associated with Amantadine Use

Purpose: To report a case of irreversible corneal endothelial cell damage associated with amantadine administration.Case summary: A 60-year-old female patient was referred with bilateral painless corneal edema. There was no history of ocular trauma or surgery. The was no sign of ocular surface inflammation, such as, conjunctival injection, either. At presentation, her best corrected visual acuity (BCVA) was 20/100 in the right eye and 20/50 in the left eye. Review of the past medical history revealed that she had been diagnosed with Parkinson’s disease and had been taking amantadine (100 mg, twice a day) for 3 years. At 7 weeks after cessation of amantadine, corneal edema was resolved bilaterally and BCVA improved to 20/30 in the right eye and 20/20 in the left eye. However, specular microscopy showed low endothelial cell density (ECD) with 886 ± 297/mm2 in the right eye and 926 ± 374/mm2 in the left eye. At 4 months after cessation, there was no corneal edema and BCVA was 20/25 in the right eye and 20/20 in the left eye. However, ECD was low with 852 ± 249/mm2 in the right eye and 903 ± 332/mm2 in the left eye.Conclusions: In cases with bilateral corneal edema without no obvious pathology, the history of medication, such as, amantadine, should be reviewed. Although cessation of amantadine can lead to improvement of corneal edema, irreversible damage of the corneal endothelial cells may remain. Serial evaluation of corneal endothelial cells is therefore recommended in patients with systemic amantadine administration.

The Impact of Donor History of Sleep Apnea on Corneal Tissue Evaluation Parameters.

The goal of this study was to explore whether the donor history of sleep apnea affects corneal tissue evaluation parameters. This was a retrospective study assessing the impact of donor history of sleep apnea in a dataset obtained from the Eversight Eye Bank. Comparative analysis and multivariate regression were used to assess differences in key parameters including endothelial cell density (ECD) and central corneal thickness. Data analyzed consisted of 50,170 tissues from 25,399 donors with no history of sleep apnea and 5473 tissues from 2774 donors with a history of sleep apnea. Tissue from donors with a history of sleep apnea showed lower ECD than those from donors with no history of sleep apnea (-51 cells/mm2, P < 0.001). Multivariate linear regression demonstrated that history of sleep apnea was a predictor of lower ECD by 13.72 cells/mm2 (P = 0.0264). Secondary analysis demonstrated that underweight and obese body mass indexes were significant predictors of increased ECD in donors with no history of sleep apnea (P < 0.0001, P = 0.025, respectively). Body mass index category was not a significant predictor of ECD in donors with a history of sleep apnea. In a smaller subset of 10,756 tissues, sleep apnea was not a significant predictor of central corneal thickness. This is the first study to demonstrate that a donor's history of sleep apnea is associated with a lower ECD in a large eye bank dataset. Future studies are needed to investigate whether history of sleep apnea affects posttransplantation outcomes.

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.

Corneal endothelial cell density and associated factors among adults at a regional referral hospital in Uganda: a cross-sectional study.

To assess the prevalence of low corneal endothelial cell density and correlates of corneal endothelial cell density among adults attending Mbarara University and Referral Hospital Eye Centre in Uganda. In this hospital-based cross-sectional study, participants 18 years and older, were enrolled. We obtained informed consent, and basic demographic data. We also conducted visual acuity, a detailed slit lamp examination, intra-ocular pressure, corneal diameter, tear-film break-up time, keratometry, A-scan, and pachymetry on all participants. A confocal microscope Heidelberg HRT3 was used to examine the central cornea and to obtain the mean cell density (cells/mm2). To calculate the proportion of low endothelial cell density, descriptive statistics were used, whereas correlates of endothelial cell density were assessed, using linear regression analyses. We evaluated a total of 798 eyes of 404 participants aged between 18 and 90 years (males = 187, females = 217). The average endothelial cell density was 2763.6 cells/mm2, and there was a decrease in endothelial cell density with increasing age, irrespective of gender. There was no significant difference in endothelial cell density between males and females. Increasing age (adjusted coefficient - 10.1, p < 0.001), history of smoking (adjusted coefficient - 439.6, p = 0.004), history of ocular surgery (adjusted coefficient - 168.0, p = 0.023), having dry eye (adjusted coefficient - 136.0, p = 0.051), and having arcus senilis (adjusted coefficient - 132.0, p = 0.08), were correlated with lower endothelial cell density. However, increasing corneal diameter (adjusted coefficient 134.0, p = 0.006), increasing central corneal thickness (adjusted coefficient 1.2, p = 0.058), and increasing axial length (adjusted coefficient 65.8, p = 0.026), were correlated with higher endothelial cell density. We found five eyes (0.63%) from different participants with a low endothelial cell density (< 1000cells/mm2). Our study established baseline normal ranges of ECD in a predominantly black African population, and found that low ECD is rare in our population. The elderly, smokers, and those with past ocular surgery are the most vulnerable. The low prevalence could be due to a lack of reference values for the black African population.

Corneal endothelial safety profile in minimally invasive glaucoma surgery.

To compare 5-year corneal endothelial safety of 3 minimally invasive glaucoma surgery (MIGS) devices (iStent inject , Hydrus Microstent, CyPass Micro-Stent). U.S. multicenter trials. Post hoc 5-year analysis from prospective randomized single-masked pivotal trials. Mild to moderate open-angle glaucoma subjects received a MIGS implant with phacoemulsification (implant + phaco) or phaco alone (control). In addition, 5-year end points comparing the implant and control groups included proportion of eyes with significant endothelial cell loss (ECL) (>30% or ≥30% vs baseline) and mean endothelial cell density (ECD). Comparable proportions of eyes in the iStent inject + phaco and control groups had significant 60-month ECL (9.4% vs 6.3%, respectively, diff: 3.2%, 95% CI, -5.0% to 11.3%, P = .77). Hydrus (20.8% vs 10.6%, diff: 10.2%, 95% CI, 3.2% to 17.2%, P = .01) and CyPass (27.2% vs 10.0%, diff: 17.2%, 95% CI, 5.6% to 28.7%, P = .02) had more eyes with ECL vs controls (iStent inject 1.49X, Hydrus 1.96X, CyPass 2.72X vs controls). Mean ECD over 60 months for iStent inject was indistinguishable vs control, whereas greater ECL was observed primarily 3 months postoperative (Hydrus) or accelerated after 2 years (CyPass). No iStent inject or Hydrus subjects developed persistent corneal edema, whereas 7 CyPass-implanted eyes developed ECL-related complications. Through 5 years postoperative, there were no differences in proportion of eyes with significant ECL or mean ECD between the iStent inject and control groups. There was greater 5-year ECL and lower ECD in the Hydrus and CyPass groups vs controls. The Hydrus ECL rate mirrored control after 3 months; the CyPass ECL rate accelerated vs control.

Association Between Endothelial Cell Density and Corneal Thickness in Medium, Short, and Long Eyes of Han Chinese Cataract Patients

To evaluate the association between the endothelial cell density (ECD) and central corneal thickness (CCT) in medium, short, and long eyes of preoperative Han Chinese cataract patients. Retrospective cross-sectional study. We consecutively enrolled 410 eyes, namely, 50 short eyes (axial length [AL]<22.0 mm), 150 medium eyes (22.0≤AL<24.0 mm), 120 medium-long eyes (24.0≤AL<26.0 mm), and 90 long eyes (AL≥26.0 mm), of 410 adult patients scheduled for cataract surgery. The ECD and CCT were determined preoperatively with a noncontact specular microscope. The association between the CCT and ECD was identified by using a multivariable regression analysis. A thin cornea was defined as having a CCT less than 500 µm. After adjusting for age, the presence of arterial hypertension, the presence of diabetes mellitus, intraocular pressure, and AL, a positive association between the CCT and ECD was identified in short eyes (linear regression coefficient [B]=3.40; standardized B [β]=0.52; P = .03), medium eyes (B = 2.33; β=0.28; P = .002), medium-long eyes (B = 1.84; β=0.25; P = .02), and long eyes (B = 2.69; β=0.41; P = .04). In the total group, the multivariable logistic analysis showed a significant link between the presence of a thin cornea and a lower ECD (odds ratio [OR]=0.80 per 100 cells/mm2 increase; P = .001). For cataract patients of Han ethnicity, a significant association between a thin CCT and a lower ECD was shown across the AL spectrum and was most prominent in short eyes. Eyes with a thin cornea are more likely to have a lower ECD.

Medical and economic impacts of managing corneas from older donors at the tissue bank-a single-center retrospective study spanning over 12 years.

To evaluate the impact of corneas from donors over 80 years of age on the activity of the North of France Tissue Bank and to determine the potential cost implications for banks using corneas from older donors. We analyzed data from a single-center retrospective cohort study of 6,023 corneas preserved at the Lille Tissue Bank between 2012 and 2023. Donors, unrestricted by age, were divided into two groups: younger (≤ 80 years) and older (> 80 years). Corneas were categorized based on endothelial cell density (ECD). Data were collected from patients who underwent corneal transplantation. A financial impact model was created to assess the effects of using corneas from different age groups on the overall benefits of corneal transplant procedures. The average donor age was 67.5 ± 14.5 years. The median age of donors gradually increased from 66 to 73 years over the 12-year study period, with donors over 80 years old representing more than 24% since 2021. Corneas from older donors had a higher discard rate (62.53% vs. 39.66%) due to poor endothelial quality and serological concerns (both p < 0.0001). Additionally, these corneas had lower ECD, with a larger proportion deemed unsuitable for grafting due to low ECD (30% vs. 8.2%). Corneas from younger donors were more often used for endothelial transplants, which require higher ECD. The mean economic benefit per cornea showed a moderate negative correlation with donor age. The net benefit of corneal transplants decreased as the proportion of donors aged over 80 years increased. It is predicted that a net benefit of zero would be attained when the proportion of donors over 80 years is 44.4%. Using corneas from donors over 80 years of age can help alleviate the shortage of donor tissue and be effective if certain quality standards are met. However, additional costs incurred by eye banks must be factored into this equation.

Comparisons of the clinical outcomes of Centurion® active fluidics system with a low IOP setting and gravity fluidics system with a normal IOP setting for cataract patients with low corneal endothelial cell density

BackgroundDuring cataract phacoemulsification surgery, the Alcon Centurion with Active Sentry can achieve a more stable anterior chamber, which allows a lower intraocular pressure (IOP) setting than the gravity fluidics system. In this randomized controlled trial, we compared these two systems’ damage to the cornea under different IOP settings.MethodsSeventy-eight eyes of 53 patients with corneal endothelial cell density (ECD) of 500∼1500/mm2 were enrolled and randomly divided into the active fluidics system (AFS) group using an Active Sentry handpiece with 30 mmHg IOP setting (40 eyes) and the gravity fluidics system (GFS) group using an Ozil handpiece with 80 cmH2O IOP setting (38 eyes). Intraoperative parameters, visual acuity, corneal edema ratio, central corneal thickness (CCT) changes as well as loss rate of ECD were analyzed.ResultsWe observed no significant differences in best corrected visual acuity (BCVA), cumulative dissipated energy (CDE), total case time, estimated fluidics usage (EFU) and ophthalmic viscoelastic devices (OVDs) usage between the two groups. The enrolled eyes were further divided into soft nucleus (27 eyes) and hard nucleus (51 eyes) subgroups. And we found less pain complaint during surgeries, lower corneal edema ratio at 1-day and 1-week visit, smaller CCT changes at 1-day visit and lower ECD loss rate at 1-month visit (p &amp;lt; 0.05) in both subgroups of the AFS group than in the GFS group, implying higher intraoperative comfort levels and less corneal damage of the AFS group with a low IOP setting.ConclusionOwing to a lower IOP setting, Centurion® Vision System with Active Sentry handpiece causes less corneal damage and pain perception during phacoemulsification for patients with low pre-operative ECD.Clinical Trial Registrationhttps://www.chictr.org.cn, identifier ChiCTR2300077865.

Corneal endothelial validation in the eye bank: differences in automated methods and repeatability

To evaluate reproducibility of endothelial cell density (ECD) measurements using the Konan Cell Check D in donor corneas by two different ophthalmologists and to compare the two automated cell count methods (center and flex-center) available in the software of this specular microscope. ECD values were quantified in 54 donor corneas by two independent investigators using the Cell Check D (Konan Medical USA Inc) with both automated cell count methods. In the center method, at least 30 contiguous cells are marked. For the flex-center method, an area is delineated and only the cells within the designated area are counted. The mean ECD was 2473.81±378.22 cells/mm2. Good ECD intergrader reproducibility for the center (ICC=0.821) and the flex-center method (ICC=0.784) were noted. Poor reliability was observed for coefficient of variation and hexagonality (ICC≤0.265). When both methods for ECD analysis were compared, a moderate correlation for the two independent graders using the two manual (center and flex-center) methods was detected (correlation coefficient of 0.678 and 0.745 for each of the investigators). Comparison between methods yielded significantly higher ECD with the flex-center method (P=0.013). When corneas were divided by ECD, those under 2200 cells/mm2 and those between 2200 and 2700 cells/mm2 also had significantly higher ECD with the flex-center method (P<0.022). ECD values are reproducible with both methods, although the flex-center method ECDs tend to be higher, particularly in cases of low ECD. Eye banks and surgeons should exercise caution in making decisions based only on small differences in ECD.

Corneal characteristics and OCT-angiography findings in pediatric glaucoma and glaucoma suspects

To analyze corneal biomechanics, specular microscopy, and optical coherence tomography-angiography findings in children with glaucoma. Pediatric patients (<18 years of age) with glaucoma (n = 38), increased cup:disk ratio and normal intraocular pressure (IOP) glaucoma suspects (n = 36), and controls (n = 67) were prospectively enrolled. Patients underwent testing with Ocular Response Analyzer, CellChek Specular Microscope, and Heidelberg OCT-A. Average age of participants was 12.4 ± 3.5 years, with no difference between groups (P = 0.71). Glaucoma patients had undergone more intraocular surgeries (P < 0.0001) and showed worse logMAR visual acuity (P < 0.0001) than suspects or controls. Central corneal thickness (CCT) was greater in glaucoma patients (642.8 ± 85.9 μm [P < 0.0001]) and suspects (588 ± 43.7 μm [P = 0.003]) compared with controls (561 ± 39.9 μm). Corneal hysteresis (CH) was decreased in eyes with glaucoma (10.4 ± 3.0) compared with controls (11.7 ± 1.5 [P = 0.006]), but not suspects (11.3 ± 2.0 [P = 0.1]). Glaucoma patients had lower endothelial cell density (2028.4 ± 862.7 [P < 0.0001]) and greater average cell area (547.2 ± 332.4 [P < 0.0005]) compared with suspects (2919.3 ± 319.1, 347.5 ± 46.2) and controls (2913.7 ± 399.2, 350.8 ± 57.7), but there was no difference in polymegathism (P = 0.12) or pleomorphism (P = 0.85). No differences in vessel density or vessel skeletal density in the retinal vascular complex (P = 0.3077, P = 0.6471) or choroidal vascular complex (P = 0.3816, P = 0.7306) were detected. Children with glaucoma showed thicker corneas with lower endothelial cell density and greater cell area, but no difference in retinal/choroidal vascular densities compared with suspects and controls.

Phacoemulsification with IOL implantation at a critical level of corneal endothelial cells

BACKGROUND: Cataract phacoemulsification is one of the most frequently performed surgical procedures, and a decrease in the corneal endothelial cell density (ECD) is the main postoperative complication leading to visual impairment. The average cell loss after phacoemulsification is 4.0112.94% within a year, and within 2 months 5.29.1%. The use of viscoelastics helps to reduce this loss, but it is impossible to completely prevent it.&#x0D; AIM: Сomparison of ECD in the pre- and postoperative period of phacoemulsification using viscoelastic of different percentages at a critical level of corneal endothelial cells.&#x0D; MATERIALS AND METHODS: The study included 60 eyes with emmetropic refraction: in the first group: 30 eyes with initial cataract and low ECD level (1694/1218 cells/mm2), an apyrogenic moderately cohesive viscoelastic 1.6% sodium hyaluronate solution (Kogevisk, Solopharm) was used, in the second group: 30 eyes with mature cataract and ECD level (1646/1183 cells/mm2) an apyrogenic, highly purified viscoelastic was used, consisting of medium-molecular fractions of chondroitin sodium sulfate 4% and sodium hyaluronate 3% (Adhevisk, Solopharm). Before surgery and a month after surgery, patients were tested for uncorrected visual acuity in the distance, ECD measurements, and intraocular pressure measurement.&#x0D; RESULTS: In phacoemulsification with IOL implantation, the use of viscoelastics of different percentages shows that the condition of the cornea remained stable a month after surgery. Postoperative ECD loss in all clinical cases, regardless of the stage of cataract, was less than 3%.&#x0D; CONCLUSIONS: Viscoelastics allow to solve the tasks set: in the case of cohesive maintaining the depth of the anterior chamber and the width of the pupil, adhesive protecting the corneal endothelium, good visualization. Rational consistent use of adhesive and cohesive components facilitates basic manipulations during phacoemulsification and IOL implantation. To do this, it is necessary to correctly use and select viscoelastic for a particular operation based on the number of endothelial cells.

Analysis of factors affecting the quality of donor corneal endothelial cells

Objective: To explore the factors influencing the quality of donor corneal endothelium. Methods: A retrospective case series study was conducted. Data from 568 donor corneas obtained from the Shandong Eye Bank between July 1, 2020, and June 30, 2021, were collected for analysis. The corneal endothelium of the donor corneas was observed using corneal endothelial microscopy to assess corneal endothelial cell density (ECD), coefficient of variation, and hexagonal cell ratio (HEX). Relevant factors of corneal donors were collected, including gender, age, cause of death, season of death, time from death to corneal retrieval, and methods of corpse preservation, to investigate their impact on the quality of donor corneal endothelium. The age factor was divided into five age groups: 0-20 years, 21-40 years, 41-60 years, 61-80 years, and >80 years. The time of corneal retrieval was divided into three periods based on the time elapsed since the donor's death: <6 hours, 6-12 hours, and >12 hours. The relationship between these factors and corneal endothelial conditions was analyzed. Results: The 568 donor corneas were obtained from 288 donors, including 225 males (78.13%) and 63 females (21.87%). The mean age was 51.77±18.48 years. The causes of death among donors were as follows: cardiovascular diseases 54.58% (275 individuals), cancer 17.96% (74 individuals), organ failure 14.26% (49 individuals), and accidents 13.20% (64 individuals). The mean time of corneal retrieval after donor death was 140 (76, 400) minutes (ranging from 30 minutes to 45 hours). Among the 145 corneas (25.53%) that had their initial corneal endothelial microscopy examination, the images were not clear, and after thorough rewarming, 106 corneas (18.7%) still had unclear images and could not be analyzed. Among the 462 corneas (81.3%) with clear images, the ECD was (2 602.23±318.40) cells/mm², the coefficient of variation was 36.61%±4.81%, and the HEX was 52.73%±7.15%. The ECD of corneas from older donors was lower compared to younger donors, and the differences between age groups were statistically significant (P<0.001). Corneas from donors who died due to accidents had a higher ECD [(2 829.88±313.90) cells/mm²] compared to those who died from cancer, cardiovascular diseases, and organ failure, and the differences were statistically significant (P<0.001). The ECD was highest when corneas were retrieved within 6 hours after death, and the difference was statistically significant (P<0.001). Older donors had higher coefficients of variation but lower HEX values (both P<0.05). Corneas retrieved after a longer time from death had higher coefficients of variation, and the difference was statistically significant (P<0.05), but there was no statistically significant difference in HEX (P>0.05). Organ failure, cryopreservation, and corneal retrieval time >12 hours were risk factors for unclear corneal endothelial imaging (all P<0.001). Among the 136 corneal endothelial images (23.94%), circular, oval, or band-shaped dark areas were observed, and corneas with dark areas had lower ECD (P<0.05). The longer the time elapsed from death to corneal retrieval, the more dark areas were observed (P<0.001). The presence of dark areas did not affect the coefficient of variation and HEX (P>0.05). Conclusion: Advanced donor age, death due to chronic diseases, longer time elapsed from death to corneal retrieval, and cryopreservation of the body lead to a decrease in the quality of donor corneal endothelium.

Clinical observation of phacoemulsification under the low perfusion pattern and low negative pressure in patients with low corneal endothelial cell density

BackgroundTo observe the safety and effect of phacoemulsification combined with intraocular lens (IOL) implantation in patients with low corneal endothelial cell density (CD) under the low perfusion pattern with low negative pressure.MethodsIn this retrospective case series study, a total of 16 patients (17 eyes) were studied. They had all been diagnosed with low corneal endothelial (CD) and cataracts in the First Affiliated Hospital of Fujian Medical University from December 2019 to October 2021. They underwent phacoemulsification combined with IOL implantation under the low perfusion pattern with low negative pressure. The variations of corneal endothelial( CD), coefficient of variation (CV) of the cell area, central corneal thickness (CCT), visual acuity, and intraocular pressure before and after the operation were observed and assessed. Then a paired t-test, repeated measures analysis of variance, and Pearson correlation analysis were adopted for data analysis.ResultsThe mean intraocular pressure of the 17 eyes was 16.88 ± 6.47 mmHg before the operation and 14.41 ± 3.10 mmHg after the operation, showing a statistically significant difference of t = 2.222, and p = 0.041. Before the operation, the mean visual acuity was 0.16 ± 0.09, and after the operation, it was 0.45 ± 0.16, displaying a statistically significant difference of t = -9.917, p < 0.001. Before and after the operation, four of the 17 eyes had no detectable CD. The mean CD of the other 13 eyes at one month after the operation (644.308 ± 106.24 cells/mm2) was lower than that before the operation (709.62 ± 119.19 cells/mm2), and the differences were statistically significant (F = 20.044, p < 0.001). However, no statistically significant differences were found in the mean CV before the operation (31.23 ± 4.21), and at one month after the operation (32.62 ± 3.80; F = 2.130, p = 0.157). Moreover, the mean CCT of 14 eyes at one month after the operation (562.72 ± 27.82 μm) was larger than that before the operation (534.79 ± 24.69 μm).ConclusionsThe low perfusion pattern with low negative pressure is safe and effective for corneal endothelial dysfunction patients complicated with cataracts.

Corneal Endothelial Morphological Alterations in Type 2 Diabetes: Associations with Glycemic Control, Disease Duration, and Diabetic Retinopathy Severity—A Cross-Sectional Study in Benghazi, Libya

Background The corneal endothelium is essential for maintaining corneal transparency and fluid regulation, and its dysfunction can lead to corneal edema and decreased visual acuity. Corneal specular microscopy is used to detect corneal disorders early. Aim This study aimed to evaluate morphological changes in the corneal endothelium of patients with type 2 diabetes mellitus (DM) using specular microscopy. Methods This study enrolled 50 individuals with type 2 diabetes and 50 nondiabetic individuals as control subjects. Patients with certain ocular and systemic conditions were excluded. The collected data included demographic information, medical history, recent hemoglobin A1c (HbA1c) values, visual acuity, ophthalmological examination, and diabetic retinopathy (DR) staging. The corneal endothelial morphology was evaluated using a noncontact specular microscope, which measured corneal endothelial cell density (ECD), central corneal thickness (CCT), coefficient of variation of cell size (CV), and hexagonality. The data were analyzed using SPSS software, and the results were presented as mean ± standard deviation, numbers, and percentages. An unpaired t-test was used to compare different means, and a p-value less than 0.05 was considered statistically significant. Results A majority of diabetic patients (62%) had diabetes for more than 10 years, and 58% of them had higher than 7.5% HbA1c levels. In terms of DR severity, 46% of patients had mild nonproliferative diabetic retinopathy (NPDR), 36% had moderate NPDR, and 10% had severe NPDR. There were significant differences between diabetic and nondiabetic groups in corneal ECD (2480 ± 223 cells/mm2 for DM group vs. 2652 ± 234 cells/mm2 for non-DM), hexagonality (39.6 ± 2.8% for DM group vs. 47 ± 2.1% for non-DM), CV (42 ± 2.9% for DM group vs. 35.5 ± 2.3% for non-DM), and CCT (550 ± 14.8 µm for DM group vs. 530 ± 9.6 µm for non-DM). Patients who had diabetes for more than 10 years had significantly lower ECD (2356 cells/mm2 vs. 2689 cells/mm2), lower hexagonality (39 vs. 41%), and higher CV (43 vs. 41%) and higher CCT (553.9 ± 4.6 vs. 545.5 ± 4.0) than those with less than 10 years of diabetes. As the severity of DR increased, there was a significant decrease in ECD (from 2641 ± 194 cells/mm2 for mild NPDR to 2310 ± 82 cells/mm2 for severe PDR), a decrease in hexagonality (from 40.9 ± 3.2% for mild PDR to 37.4 ± 1.1% for severe PDR), an increase in CV (from 40.1 ± 2.3% for mild PDR to 44 ± 2.9% for severe PDR), and an increase in CCT (from 543.7 ± 13.8 for mild PDR 563.8 ± 2.9 for severe PDR). Conclusion This study revealed that type 2 diabetes is associated with significant reductions in ECD and hexagonality, as well as an increase in CV and CCT. The severity of DR and the duration of diabetes were correlated with changes in these parameters. These findings underscore the need for a comprehensive evaluation of corneal health in diabetic patients.

Влияние антиглаукомных препаратов и их компонентов на клеточную культуру эндотелия роговицы человека

Purpose. Evaluation of cytotoxicity of antiglaucoma drugs and preservative – benzalkonium chloride (BAK) in human corneal endothelial cells (CECs) in vitro. Material and methods. High-CEC-density colonies were used as a monolayer (intact endothelium in vivo) and single CECs were regarded as low-HCEC-density layer in bullous keratopathy. Dorzolamide, brimonidine, timolol (preserved and BAK-free) were diluted with medium up to 1/10000, 1/1000, 1/100. BAK was diluted according to its concentration in these solutions. Following exposure to test solutions for 24 hours, morphological features of both CEC-models were identified with phase-contrast microscope, CECs survival was measured using MTS assay. Results. Dorzolamide and Timolol, preservative-free, 1/1000 and 1/100 dilutions, induced structural changes of single CECs. Timolol, preservative-free, 1/1000 and 1/100 dilutions, caused changes of CEC-monolayer. Dorzolamide, brimonidine and timolol (preservative-free, 1/100 dilutions) have not caused the decline of CEC viability in both models. Dorzolamide, preserved, 1/100 dilution, was toxic to CEC-monolayer. Brimonidine and timolol (preserved, 1/100 dilutions) induced CECs'death in monolayer. Low single CECs viability (29%) was detected after exposure to Dorzolamide, preserved, 1/100 dilution. High cytotoxicity of brimonidine and timolol (both preserved, 1/100 dilutions) to CEC-monolayer was confirmed by MTS-test – 25% and 3%, respectively and to single CECs – 23,4% and 4,2%, respectively. BAK showed similar level of CECs'toxicity as preserved drugs. So, the cytotoxicity of these drugs was induced by BAK as a component. Conclusions. High concentrations of preserved antiglaucoma ophthalmic solutions may disturb CECs. Administration of such drugs is not reasonable in eyes with low corneal endothelial cell density. Keywords: dorzolamide, brimonidine, timolol, benzalkonium chloride, corneal endothelium, cytotoxicity

Meta-analysis of corneal endothelial changes after phacoemulsification in diabetic and non-diabetic patients

BackgroundCurrently, there is still controversy about the differential changes in corneal endothelium function and morphology after phacoemulsification between Diabetes Mellitus (DM) and non-Diabetes Mellitus (non-DM) patients. In this study, we aimed to evaluate the influence of phacoemulsification on the corneal endothelium in DM and non-DM patients.MethodsDatabases of PubMed, Embase, Web of Science, and the Cochrane Library were searched for studies published between January 1, 2011 and December 25, 2021. The weighted mean difference and 95% confidence interval were used to estimate the outcomes of statistical analyses performed.ResultsThirteen studies involving 1744 eyes were included in this meta-analysis. No significant difference was observed in the central corneal thickness (CCT), endothelial cell density (ECD), coefficients of variation (CV), or hexagonal cell percentage (HCP) between the DM and non-DM groups (CCT: P = 0.91; ECD: P = 0.07; CV: P = 0.06; HCP: P = 0.09) preoperatively. The CCT was significantly thicker in the DM group at 1 month (P = 0.003) and 3 months (P = 0.0009) postoperatively, and there was no significant difference at 6 months postoperatively (P = 0.26) than non-DM group. The CV was significantly higher and HCP was significantly lower in the DM group at 1 month (CV:P < 0.0001, HCP: P = 0.002), with no significant difference at 3 months (CV: P = 0.09, HCP: P = 0.36) and 6 months (CV: P = 0.32, HCP: P = 0.36) postoperatively than non-DM group. DM patients had lower ECD than non-DM patients at all postoperative time points (1 month, 3 months: P < 0.00001, 6 months: P < 0.0001).ConclusionsThe influence of phacoemulsification on corneal endothelial damage is greater in diabetic patients. Moreover, the recovery of corneal endothelial function and morphology is delayed in these patients. Clinicians should be more attentive to the corneal health of DM patients when considering phacoemulsification.

Risk factors for failure of pre-cut eye bank UT-DSAEK grafts

The main risk factors for graft failure in penetrating keratoplasty are well known. However, few studies have examined donor characteristics or more precise data on endothelial keratoplasty. This was a retrospective, single-center study at the Nantes University Hospital, aiming to identify factors predictive of one-year success or failure of eye bank UT-DSAEK endothelial keratoplasty grafts prepared between May 2016 and October 2018. The outcome measure was success or failure at 12months post keratoplasty. One hundred and five grafts were included: 93 successes and 12 failures at 12months. The failure rate was higher in 2016 compared to 2017 and 2018. The characteristics associated with higher failure rate wereelderly donor, shorter time between harvesting and grafting, lower endothelial cell density, significant pre-graft endothelial cell loss, re-graft for Fuchs dystrophy, history of corneal transplant. Our results are consistent with those in the literature. However, some factors, such as the type of corneal harvesting or pre-graft endothelial cell loss, were not found. UT-DSAEK has demonstrated better results than DSAEK, but still appears to be somewhat inferior to DMEK. The main factor for graft failure in our study was an early re-graft within 12months. However, the low incidence of graft failure limits interpretation of these results.