Percentage Of Hexagonal Cells Research Articles

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/mm 2 ) and non-Hispanics (2,483±380 cells/mm 2 , 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.

Changes and Influencing Factors of Corneal Endothelial Cells and Central Corneal Thickness after Pediatric Cataract Surgery

Introduction: This study aimed to examine the impact of cataract surgery on the corneal endothelium and central corneal thickness (CCT) in pediatric patients, and to identify the factors associated with corneal alterations. Methods: This retrospective study included consecutive children undergoing bilateral or unilateral cataract surgery and intraocular lens implantation at the Eye Hospital of Wenzhou Medical University, with or without posterior capsulorhexis and anterior vitrectomy, and an age-matched normal control group. This study aimed to assess whether changes in corneal parameters, including CCT, corneal endothelial cell density (CD), average cell area (AVE), standard deviation of size (SD), coefficient of variation (CV), percentage of hexagonal cells (6A) before and after surgery, and endothelial cell loss (ECL) differed among the bilateral cataract, unilateral cataract, and control groups. Furthermore, the potential effects of anterior vitrectomy, axial length, preoperative anterior chamber depth, surgical duration, horizontal corneal diameter, intraoperative pupil diameter (PD), and the number of corneal sutures on corneal endothelial parameters and CCT were investigated. Results: A total of 107 eyes from 107 children were included in the study. In the bilateral cataract group, CD significantly decreased, AVE and CCT significantly increased, and ECL was significantly higher than in the control group. The unilateral cataract group also exhibited a significant increase in CCT. Additionally, the number of corneal sutures was negatively correlated with CD, and PD was negatively correlated with CV in the unilateral cataract group. Conclusion: Cataract surgery in pediatric patients results in increased CCT, reduced CD, and morphological changes in corneal cells. A greater number of corneal sutures and a smaller PD increased the risk of CD reduction and elevated CV in the unilateral cataract group, underscoring the need for ophthalmologists to minimize corneal damage in these children.

Comprehensive assessment of corneal microstructural changes following V4c implantable collamer lens surgery using in vivo confocal microscopy

BackgroundImplantable Collamer Lense (ICL) presents a viable alternative to conventional refractive surgeries, but their impact on corneal microstructure remains unclear. By employing in vivo confocal microscopy (IVCM), we examined changes in stromal and endothelial cells following the insertion of V4c ICLs, with the goal of enhancing post-surgical care and outcomes.MethodsIn this longitudinal investigation, we conducted detailed preoperative assessments on 103 eyes from 53 participants. Follow-up evaluations were carried out after surgery at set intervals: one day, one week, one month, three months, six months, and twelve months. We used IVCM to analyze changes in stromal and endothelial cells. To assess differences between pre- and post-surgery variables and to investigate correlations with age, axial length (AL), and spherical equivalent refraction (SER), we applied a repeated measures mixed-effects model, with statistical significance set at P < 0.05.ResultsNo vision-threatening complications were reported post-surgery. Significant reductions in stromal cell density (SCD) were observed postoperatively, with anterior and mid- SCD reaching their lowest values at 3 months and posterior SCD at 1 month, remaining below baseline at 12 months. endothelial cell density (ECD) and percentage of hexagonal cells (PHC) decreased initially, recovering by 12 months. Conversely, endothelial cellular area (ECA) and coefficient of variation of cell size (CoV) increased postoperatively, with the most significant change at 1 week. Endothelial deposits were detected in 49 of 101 eyes on postoperative day 1, half of them were absorbed within 3 months post-surgery. Changes in posterior SCD were negatively related to AL, while AL, SER, lens thickness showed associated with endothelium changes.ConclusionOur findings elucidate the corneal microstructural changes following V4c ICL implantation, particularly the significant early reductions in stromal and endothelial cell densities. We recommend careful management of viscoelastics during surgery to minimize endothelial deposits that may harm the endothelium. Enhanced early postoperative monitoring and these surgical adjustments can lead to improved surgical and post-surgical care, ultimately supporting better patient recovery.

Changes in Corneal Endothelial Cells and Central Corneal Thickness in Pseudoexfoliation Syndrome

Purpose: The aim of the research is to investigate the impact of pseudoexfoliation syndrome (PEX) on corneal endothelial cells and central corneal thickness. Methods: In this analytic case-control study, the research sample included 60 patients (120 eyes), which was divided into two groups: the PEX group, 30 patients (60 eyes) obtained inclusion criteria and the control group, 30 patients (60 eyes) for result comparison, from patients visiting the ophthalmic clinic at Tishreen University Hospital. PEX degree was assessed using a slit lamp and the morphology of endothelial cells: endothelial cell density (ECD), coefficient of variation (COV) , percentage of hexagonal cells (EX%), average cell area (Avg.Cell Area) and central corneal thickness (CCT) were assessed using a specular microscope. Results: The average of ECD was lower in the PEX group compared with the control group (p-value = 0.0001). The average of EX% was lower in the PEX group compared with the control group (p-value = 0.0001). No statistically significant differences were observed between the research groups in COV values (p-value = 0.9). The Avg.Cell Area was higher in the PEX group compared with the control group (p-value = 0.003). The average of CCT was lower in the PEX group compared with the control group (p-value = 0.04). Conclusion: Corneal endothelial cells morphology and central corneal thickness are affected in eyes with PEX syndrome, and these changes increase with the severity of PEX.

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.

Neuropeptide alpha-Melanocyte stimulating hormone preserves corneal endothelial morphology in a murine model of Fuchs dystrophy

Fuchs endothelial corneal dystrophy is a heterogenous disease with multifactorial etiology, and genetic, epigenetic, and exogenous factors contributing to its pathogenesis. DNA damage plays a significant role, with ultraviolet-A (UV-A) emerging as a key contributing factor. We investigate the potential application of neuropeptide α-melanocyte stimulating hormone (α-MSH) in mitigating oxidative stress induced endothelial damage. First, we examined the effects of α-MSH on a cultured human corneal endothelial cell line (HCEnC-21T) exposed to hydrogen peroxide (H2O2) induced oxidative DNA damage. We performed immunofluorescence and flow cytometry to assess DNA damage and cell death in the cultured cells. Additionally, we used an established mouse model that utilizes ultraviolet light to induce corneal endothelial cell damage resulting in decreased CEnC number, increased cell size variability, and decreased percentage of hexagonal cells. This endothelial decompensation leads to an increase in corneal thickness. Following UV-A exposure, the mice were systemically treated with α-MSH, either immediately after exposure (early treatment) or beginning two weeks post-exposure (delayed treatment). To evaluate treatment efficacy, we analyzed CEnC density and morphology using in vivo confocal microscopy, and central corneal thickness using anterior segment optical coherence tomography. Our findings demonstrated that α-MSH treatment effectively protects HCEnC-21T from free-radical induced oxidative DNA damage and subsequent cell death. In vivo, α-MSH treatment, mitigated the loss of CEnC density, deterioration of cell morphology and suppression of the resultant corneal swelling. These results underline the potential application of α-MSH as a therapeutic agent for mitigating corneal endothelial damage.

Evaluation of the effect of atorvastatin on corneal endothelial cells during the initial 12-month period after acute coronary syndrome.

It was aimed to compare corneal endothelial changes during the initial 12-month period in which patients started using atorvastatin after a diagnosis of acute coronary syndrome (ACS). Forty-six participants (group 1) who underwent cardiac angioplasty and stenting for ACS and started using 80 mg atorvastatin in the early period were included in the study. In the study, a control group comprising 71 healthy adults (group 2) was included. These individuals did not use medication for any known systemic disease, had never taken statins, had no history of ocular surgery, and did not have any cornea-related eye diseases. Baseline and 12th month endothelial evaluations of group 1 and 2 participants were compared using specular microscopy. There were 28 female and 18 male participants in group 1 and 48 female and 23 male participants in group 2 (P = 0.455). The mean baseline corneal endothelial cell density (CECD) was not significantly higher in group 1 compared to group 2 (2471.4 ± 200 cells/mm2 vs 2428.2 ± 539.8 cells/mm2, P = 0.230). When the change between baseline and 12th month CECD was examined, the decrease in group 2 was significantly different from that in group 1 (-15,2 ± 31,9 and -44,8 ± 49,6, P = 0,002). Although the percentage of hexagonal cells decreased significantly in group 2 participants, no significant change was observed in group 1 (respectively; P < 0.001, P = 0.073). The endothelial cell coefficient of variation did not differ significantly in group 1 participants over a 1-year period (P = 0.192), and a significant increase was observed in group 2 (P < 0.001). This study revealed that atorvastatin may have a positive effect on corneal endothelium cell density and morphology.

Comparison of automated corneal endothelial cell analysis in healthy and postoperative eyes with phakic intraocular lens: a cross-sectional study and literature review

PurposeMeasurement of corneal endothelial cells is critical for postoperative evaluation of phakic intraocular lens (pIOL) surgery. However, inter-instrument differences in corneal endothelial cell density (ECD) after pIOL implantation have not yet been reported. This study aimed to compare automated corneal endothelial cell analysis between CellChek-20 (Konan Medical, Hyogo, Japan) and EM-4000 (Tomey, Nagoya, Japan) in healthy and postoperative eyes with pIOL.MethodsWe retrospectively analyzed 154 healthy and 236 postoperative eyes after pIOL surgery. Endothelial cell measurements were performed using CellChek-20 and EM-4000 with autofocusing and automated image analysis. ECD, percentage of hexagonal cells (HEX), coefficient of variation in cell size (CoV), and central corneal thickness (CCT) were compared between the two devices.ResultsThe ECDs of the two devices were highly correlated in both healthy (Spearman’s correlation coefficient [r] = 0.805; p < 0.001) and postoperative (r = 0.901; p < 0.001) groups. ECD from CellChek-20 was higher than EM-4000 in both healthy (mean difference = 228.9 cells/mm2; p < 0.001) and postoperative (mean difference = 115.6 cells/mm2; p < 0.001) groups. The CCT values also showed a strong correlation in healthy eyes (r = 0.974; p < 0.001) and in postoperative eyes (r = 0.936; p < 0.001); however, significant inter-instrument differences were observed. HEX and CV showed significant differences and relatively weak correlations (r < 0.7) between the two devices in both healthy and postoperative groups.ConclusionThe ECD values between the two instruments were correlated, but that of the CellChek-20 was significantly higher than that of the EM-4000 in both healthy and postoperative eyes after pIOL surgery. Most previous studies have also shown that the Konan software overestimated the ECD compared to other products in automatic measurement mode. The possibility of measurement bias should be considered when replacing equipment used for corneal endothelial cell measurements.

Effect of Anterior Uveitis on Corneal Endothelial Cells

Objective: Investigating the impact of anterior uveitis on changes occurring in corneal endothelial cells. Methods: In this prospective cross-sectional study (cases and controls), the research sample included 43 patients (86 eyes) from the ophthalmic clinic attendees at Tishreen University Hospital in Latakia during the period 2023-2024. Results: The average corneal endothelial cell count was lower in the anterior uveitis group, both granulomatous (2074.16±173.70 cells/mm²) and nongranulomatous (2188.38±165.7 cells/mm²) types, compared to the control group (2696.1±136.60 cells/mm²) with a (p-value &lt;0.01) in all age groups studied. The average percentage of hexagonal cells was lower in the both granulomatous (42.41±2.6%) and non- granulomatous (47.0±2.2%) types, compared to the control group (61.4±2.0%) with a (p-value &lt;0.01) in all age groups studied. The average cell volume change coefficient was higher in the anterior uveitis group, both granulomatous (40.16±2.1) and non-granulomatous (34.70±1.08) types, compared to the control group (29.8±1.36) with a (p-value &lt;0.01) in all age groups studied. Host and disease-related characteristics had no effect on the measured results) p-value=0.184(. ECC was negatively correlated to the duration of uveitis (a=-0.513; p-value&lt;0.001), maximum intraocular pressure during the course of disease (a=-0.472; p-value = 0.0001), and the number of attacks (a=-0.515; p-value&lt;0.001). Conclusion: Corneal endothelial cells are affectd in patients with anterior uveitis, and this negative impact increases with the duration of the disease, the number of attacks, and the presence of elevated intraocular pressure. This negative impact is more pronounced in granulomatous uveitis.

Changes in corneal endothelial cells after scleral-fixated intraocular lens surgery in children with congenital ectopia lentis: 2-year follow-up.

To investigate the changing patterns of corneal endothelial cells and the associated factors in children with congenital ectopia lentis (CEL) after scleral-fixated intraocular lens (SF IOL) surgery. Zhongshan Ophthalmic Center, Guangzhou, China. Retrospective study. Patients were divided into the surgery group and the control group. Central endothelial cell density (ECD), coefficient of variation in cell size, the percentage of hexagonal cells (hexagonality), average cell size (AVG), and central corneal thickness were analyzed for both groups at baseline and each follow-up visit. Clinic characteristic, ocular parameters, IOL decentration, and IOL tilt of patients in the surgery group were collected. Multiple linear regression was performed to assess the potential associated factors for the postoperative changes in corneal endothelial cells in the surgery group. After 2-year follow-up, the decline of ECD was 17.8% (95% CI, -21.8 to -13.9) in the surgery group and -3.1% (95% CI, -5.2 to -1.0) in the control group ( P < .001), while the increase of AVG was 24.3% (17.1-31.6) in the surgery group and 2.7% (1.0 to 4.5) in the control group ( P < .001). Multivariate analysis showed that axial length (AL) ≥24 mm and white-to-white (WTW) <12.2 mm were significantly associated with greater loss of ECD (β = -241.41, 95% CI, -457.91 to -24.91, P = .030 and β = 251.63, 95% CI, 42.10-461.17, P = .020, respectively) and AL ≥24 mm was significantly positively associated with the increase of AVG (β = 34.81, 95% CI, 0.90-68.71, P = .044). The SF IOL had a significant impact on corneal endothelium in children with CEL. More attention should be paid to monitor postoperative corneal endothelium change during long-term follow-up in CEL children, especially for those with longer AL and smaller WTW.

Corneal Endothelial Cells and Central Corneal Thickness in Pseudoexfoliation Patients

Objective: Investigating the impact of pseudoexfoliation syndrome on changes occurring in corneal endothelial cells and central corneal thickness, while assessing the influence of the degree of pseudoexfoliation on endothelial cell changes. Methods: In this analytic case-control study (Cross Sectional), the research sample included 60 patients (120 eyes) from the ophthalmic clinic attendees at Tishreen University Hospital in Latakia during the period 2023-2024. Results: The average corneal endothelial cell count was lower in the pseudoexfoliation group (2218.91±311.5 cells/mm²) compared to the control group (2559.82±290.7 cells/mm²) with a (p-value of 0.0001). The average percentage of hexagonal cells was lower in the pseudoexfoliation group (48.55±14.9 %) compared to the control group (62.32±9.7%) with a (p-value of 0.0001). No statistically significant differences were observed between the research groups in terms of average cell volume change coefficient with a (p-value of 0.9). The average cell area was higher in the pseudoexfoliation group (487.92±71.3 µm²) compared to the control group (419.94±72.2 µm²) with a (p-value of 0.003). The average central corneal thickness was lower in the pseudoexfoliation group (515.93±41.9 µm) compared to the control group (544.22±26.6 µm) with a (p-value of 0.04). We observed increased changes in corneal endothelial cells and central corneal thickness with an increase in the degree of pseudoexfoliation. Conclusion: Corneal endothelial cells and central corneal thickness are affected in patients with pseudoexfoliation syndrome, and these changes increase with severity of pseudoexfoliation.

Corneal endothelial cell morphology in children with autosomal recessive Alport syndrome: a longitudinal study

ABSTRACT Purpose To evaluate the corneal endothelial cell morphology in children with autosomal recessive Alport syndrome (ARAS). Methods This is a longitudinal, prospective cohort study that evaluated pediatric patients with genetically diagnosed ARAS. Fifty-eight eyes of 29 pediatric patients (12 patients, 17 controls) underwent a full ophthalmic examination. Corneal endothelial cell density (ECD) (cells/mm²), coefficient variation (CV) of cell area (polymegathism), the percentage of hexagonal cells (HEX) (pleomorphism), and central corneal thickness (CCT) were analyzed automatically using a noncontact specular microscopy. Results The mean ECD was 2904 ± 355.48 cell/mm² in the ARAS group and 3263.20 ± 261.71 cell/mm² in the control group (p = 0.004). In the ARAS group, the mean CV was 46.53 ± 10.43, which was significantly higher than that in controls (p = 0.026). The mean HEX was 48.86 ± 14.71 in the ARAS group and 59.06 ± 10.64 in the control group (p = 0.038). The mean CCT was 565.26 ± 39.77 µm in the ARAS group and 579.66 ± 31.65 µm in the control group (p = 0.282). The comparison of endothelial cell characteristic of the ARAS group with 1-year follow-up is as follows: The mean ECD decreased from 2904 ± 355.48 cell/mm² to 2735 ± 241.58 cell/mm² (p = 0.003). The mean CV increased from 46.53 ± 10.43 to 47.93 ± 10.50 (p = 0.471). The mean HEX decreased from 48.86 ± 14.71 to 48.50 ± 10.06 (p = 0.916). The mean CCT decreased from 565.26 ± 39.77 µm to 542.86 ± 40.39 µm (p = 0.000). Conclusion Measurement of ECD and percentage of hexagonality can also be used as an indicator of the health of the corneal endothelium. In this study, the mean ECD and HEX were significantly lower in ARAS group than in age-matched pediatric controls. Polymegathism, which reflects cellular stress, was statistically significantly higher in ARAS group. The mean ECD and CCT decreased significantly at 1-year follow-up. This study may demostrated that endothelial damages and stress in ARAS patients appear in childhood and show a rapid increase with age.

The effect of irrigation and aspiration on the corneal endothelial cell density in patients undergoing Implantable Collamer Lens with a central hole implantation for myopia correction.

In the conventional technique, viscoelastic agents are typically rinsed away with balanced salt solution (BSS), but it may lead to a series of complications such as viscoelastic residue, anterior chamber instability and intraoperative TICL rotation. The utilization of irrigation and aspiration (I/A) has been shown to be effective in maintaining anterior chamber stability, reducing the incidence of postoperative high intraocular pressure, and minimizing postoperative fundus complications. However, there is a lack of previous studies investigating the impact of I/A on corneal endothelial cells during ICL implantation. The objective of this study was to examine the effect of I/A on corneal endothelial cells in patients undergoing myopia correction through implantation of Implantable Collamer Lens with a central hole (V4c ICL). A retrospective selection was made of 344 eyes from 172 patients who underwent V4c ICL implantation and I/A to remove viscoelastic agent from the anterior chamber between 2021 and 2022. The intraocular pressure (IOP) was measured at 1h, 2h and 3h after surgery. Corneal endothelial cell density (ECD), coefficient of variation in cell size (CV), standard deviation of cell area (SD), and percentage of hexagonal cells (HEX) were evaluated at 1week postoperatively to assess corneal endothelial cells. The first two represent polymegethism or morphological variation, while the third parameter represents the degree of polymorphism of the corneal endothelial cells. Electronic medical records were utilized for data collection purpose. All surgeries proceeded without complications. The IOP was 16.50 ± 3.42mmHg (range: 11.5-22.3mmHg) prior to surgery and increased to 21.25 ± 5.61mmHg (range: 9.5-34.8mmHg), 19.85 ± 5.18mmHg (range: 11.4-36.2mmHg) and finally settled at an average of 18.81 ± 4.57mmHg (range: 10.1-38.8mmHg) at the respective time points of 1h, 2h and 3h after surgery. The preoperative ECD was recorded as being approximately 3004 ± 295 cell/mm2, which exhibited a marginal decreased of 1.17% postoperatively, resulting in an average ECD value of 2969 ± 303 cell/mm2 one week after surgery (P = 0.12). Similarly, the preoperative CV was determined as 31.10 ± 3.78%, and it experienced a slight reduction with an average CV value of 30.74 ± 3.77% at week after surgery (P = 0.21). And, the preoperative SD was reported as 104.76 ± 17.26, and it remained virtually unchanged with an average SD value of 104.85 ± 18.75 at one week after surgery (P = 0.95). The preoperative HEX was calculated as 55.38 ± 8.94%, and it remained its stability with an average HEX value of 55.45 ± 8.73% one week after surgery (P = 0.92). The utilization of I/A led to a slight decrease in postoperative ECD when compared to conventional surgical techniques. Nevertheless, the reduction in ECD remained within acceptable limits, taking into accout the avervantaged it offered, such as stabilization of the anterior chamber and decreased occurrence of viscoelastic residue after surgery. It is challenging to anticipate the long-term safety of corneal endothelial cells based on current short-term studies. However, this study provides a valuable reference indicating that neither anterior chamber irrigation nor I/A aspiration have an adverse impact on the safety of corneal endothelial cells in the short term. Further research is imperative to enhance our understanding of their effects over an extended period.

Assessment of performance and safety of Corneal Chamber hypothermic storage medium and PSS-L corneal rinsing solution in human and porcine corneas

PurposeTo prove the safety and performance of the hypothermic corneal storage medium "Corneal Chamber" and the rinsing solution "PSS-L" in support of the new Conformité Européenne (CE) certification process in...

COVID-19 related changes in corneal curvature and endothelium after mild infection

PurposeTo investigate subclinical corneal changes using corneal topography in the evaluation of corneal curvature and specular microscopy in the evaluation of the endothelial layer after mild coronavirus disease 2019 (COVID-19). MethodsIn this prospective study, 112 eyes of 56 individuals with mild COVID-19 who recovered were investigated. Mean cell density (CD), mean coefficient of variation (CV), mean percentage of hexagonal cells, mean cell area (AVG), and central corneal thickness (CCT) were recorded from specular microscopy. K readings, including simulated keratometry flat (K1), simulated keratometry steep (K2), average keratometry (Kmean) and maximum keratometry (Kmax), pachymetric measurement and central corneal thickness (CCT), corneal volume (CV), topographic astigmatism (TA), curvature asymmetry front (CAf) and curvature asymmetry back (CAb) were recorded from corneal topography. Best corrected visual acuity (BCVA), spherical equivalant and biometric measurements were recorded. ResultsThe mean time interval between examinations before and after COVID-19 infection was approximately one year. Analysis of specular microscopy data showed a statistically significant change in all endothelial cell parameters (p<0.001) except the cell count (p = 0.358). The median (range) endothelial cell density (ECD) value was significantly lower after COVID-19 at 2356 (2289–2400) than before, when it was 2596 (2545–2640). Furthermore, CCT values showed a significant increase (p<0.001). The topographic values including K2, Kmax and TA and biometric measurements did not change. The Spherical Equivalant (SE) values showed significant myopic progression after COVID-19 (p<0.001). ConclusionEndothelial parameters changed more than the changes in corneal curvature and ocular biometric measurements after mild COVID-19. The decrease in endothelial cell number and hexagonality and increase in polymorphism after COVID-19 were striking.

Qualitative and quantitative endothelium changes after cataract surgery: ultrasound phacoemulsification vs. nanolaser technique.

The aim of this study was to evaluate corneal endothelial cell density and morphology, central corneal thickness, and best visual acuity using ultrasound (US) phacoemulsification or nanosecond laser technique. Department of ophthalmology, Nabeul, Tunisia. Prospective cohort study. This study included eyes with nuclear cataracts with a density grade of 1, 2, 3, or 4 according to LOCS III, divided into two groups; group 1 had conventional US, and group 2 had nanosecond laser. The endothelial cell density (ECD), coefficient of variation (CoV) in cell size, percentage of hexagonal cells, central corneal thickness (CCT) and best visual acuity (VA) were evaluated during 24 months. Seventy-four eyes had uneventful surgery, 40 in group 1, 34 in group 2. Three procedures in group 2 required conversion to standard phacoemulsification. The mean ECD decreased from 2616.4 ± 194.6 cells/mm2 in group 1 preoperatively to 2088.4 ± 229.9 after 2 years. In group 2, it decreased from 2611.8 ± 186.5 cells/mm2 to 2276.4 ± 163.8 after 2 years. The change was statistically significant in both groups. The decline of the mean ECD in group 2 was significantly less important than in group 1 (p = <10-2). The mean percentage of hexagonal cells was 45.18 ± 4.9 preoperatively and 43.5% ± 6.6 after 2 years in group 1. In group 2, it remained almost stable with 45.6 ± 5.1 and 45.4% ± 6.6 preoperatively and after 2 years, respectively. Preoperatively, the mean CoV was 0.39 ± 0.037 in group 1 and 0.38 ± 0.04 in group 2. After 2 years, it was 0.38 ± 0.04 and 0.37 ± 0.038 in group 1 and group 2, respectively. The changes of the mean CoV and the mean percentage of hexagonal cells were significant in both groups, but the difference between the groups was significant only during the six first months postoperatively. In preoperative, the mean corneal central thickness was 509.7 ± 19.5 in group 1 and 510.3 ± 20.4 in group 2. In both groups, the mean corneal thickness increased on D1 postoperatively to 550.9 in group 1, and 528.2 in group 2. The mean corneal thickness decreased more rapidly after 1 week in group 2, to find the initial values. Visual acuity improved from 0.76 Log Mar ± 0.5 at enrolment to 0.45 Log Mar ± 0.2, and 0.033 Log Mar ± 0.086 in group 1 at 1 day post-operative and after 24 months, respectively and from 0.58 Log Mar ± 0.28 to 0.2 Log Mar ± 0.09 and 0.035 Log Mar ± 0.083, respectively in group 2. There was no significant difference in VA at each follow-up between groups except for day 1. Our study showed lower corneal tissue trauma, and lower endothelial cell loss in the laser cataract surgery compared to phacoemulsification.Clinical trial registration: (https://classic.clinicaltrials.gov/ct2/show/NCT05886283), identifier NCT05886283.

Evaluation of the corneal thickness and endothelial changes following uncomplicated phacoemulsification in diabetic and non-diabetic patients with pseudo-exfoliation syndrome by specular microscopy.

To evaluate corneal endothelial cell changes following uncomplicated phacoemulsification in diabetic patients with PEX, compared with diabetic patients and non-diabetic patients with PEX. This prospective, comparative, non-randomized cohort study included 61 eyes of 61 patients who were diagnosed as having senile cataract. Patients were divided into three groups: Group (1) included 19 eyes of patients with DM and PEX, group (2) included 22 eyes of diabetic patients, and group (3) included 20 eyes of patients with PEX. All included patients had uncomplicated phacoemulsification with IOL implantation. Patients were examined by non-contact specular microscopy (NIDEK, CEM-530, Japan), preoperatively and postoperatively at regular follow-up periods (one, three, and six months postoperatively) with analysis of the endothelial cell density, percentage of hexagonal cells, CV, and CCT. By the end of follow-up period, there was a statistically significant reduction in ECD and HEX with a significant increase in CV and CCT in group one (DM-PEX). In group two (DM), a statistically significant decrease in ECD and HEX with a significant increase in CCT was reported, while in group three (PEX), the only significant difference was found in the form of ECD reduction. Patients with DM and PEX had significant changes regarding ECD, CV, HEX, and CCT which were more pronounced than in patients with DM only or PEX only. More attention should be paid while operating on diabetic patients with PEX to save corneal endothelium and decrease postoperative complications. The study was retrospectively registered (16 July 2021) on ClinicalTrials.gov (NCT04965168).

Comparison of implantation of posterior chamber phakic IOL implantation and laser vision correction in terms of corneal endothelial cells: 3-year observational paired-eye study.

To compare the postoperative endothelial cell counts of EVO-implantable collamer lenses (ICLs) with a central hole (V4c and V5) and laser vision correction surgery (laser in situ keratomileusis or photorefractive keratectomy). B&VIIT Eye Center, Seoul, South Korea. Retrospective observational and paired contralateral study. 62 eyes of 31 patients who underwent EVO-ICLs with a central hole implantation in one eye (phakic intraocular lens [pIOL] group) and laser vision correction in the contralateral eye (LVC group) to correct refractive errors were retrospectively reviewed. Central endothelial cell density (ECD), percentage of hexagonal cells (HEX), coefficient of variation (CoV) in cell size, and adverse events were evaluated for at least 3 years. The endothelial cells were observed using a noncontact specular microscope. All surgeries were performed, without complications during the follow-up period. The mean ECD loss values compared with the preoperative measurements were 6.65% and 4.95% during the 3 years after pIOL and LVC, respectively. There was no significant difference in ECD loss compared with the preoperative values (paired t test, P = .188) between the 2 groups. No significant loss in ECD was observed at any timepoint. The pIOL group showed higher HEX ( P = .018) and lower CoV ( P = .006) values than the LVC group at the last visit. According to the authors' experience, the EVO-ICL with a central hole implantation was a safe and stable vision correction method. Moreover, it did not induce statistically significant changes in ECD at 3 years postoperatively compared with LVC. However, further long-term follow-up studies are required to confirm these results.

Examination of the Corneal Endothelium in Pediatric Patients With COVID-19.

To investigate the effects of coronavirus disease 2019 (COVID-19) infection on the corneal endothelium in children. This retrospective study included 46 pediatric patients with COVID-19 infection and 38 healthy controls. Specular microscopy measurements were analyzed, and measurements were obtained from images showing at least 100 cells with clear borders. Mean endothelial cell density, mean hexagonal cell percentage (HEX), mean coefficient of variation (CV), central corneal thickness, and mean cell area were evaluated. Specular microscopy data showed that the CV values were 2.442±6.517 in the healthy control group (HCG) and 2.659±5.119 in the COVID-19-affected group (CAG) ( P =0.003). The hexagonality of the HCG and CAG were 6.916±8.271 and 6.683±5.885, respectively ( P =0.011). A decrease in the HEX and an increase in the CV were observed in the corneal specular microscopic examination of children with COVID-19 infection. These results are important in demonstrating the corneal effects of COVID-19 infection in children.

The effect of hyperbaric oxygen therapy on corneal endothelial structure and anterior segment parameters

Purpose To assess the effect of hyperbaric oxygen therapy (HBOT) on corneal endothelial structure and anterior segment parameters in healthy eyes. Methods 17 eyes of 17 patients who were scheduled to receive HBOT for other than ophthalmologic indications were investigated in this prospective study. Central corneal thickness (CCT) and corneal endothelial properties were evaluated using a specular microscope. Endothelial cell density (ECD), average cell area (AVG), coefficient of variation in cell size (CV), percentage of hexagonal cells (HEX), CCT, intraocular pressure (IOP), spherical equivalent (SE), axial length (AL) and anterior chamber depth (ACD) values were measured before the HBOT, after the 1st session, and after the 20th session of therapy. Results 47% of the patients (n = 8) received HBOT because of avascular necrosis, 35% (n = 6) due to sudden hearing loss, 12% (n = 2) for diabetic foot, and 6% (n = 1) for wound infection. The mean IOP was 14,80 mmHg before HBOT, 14,20 mmHg after the 1st session, and 13,73 mmHg after the 20th session. The mean ACD was 3,38 mm before HBOT, 3,34 mm after the 1st session, and 3,16 mm after the 20th session. Although the mean IOP and ACD decreased after HBOT sessions, it was not statistically significant (p > 0.05). A significant reduction was observed in SE values after 20 sessions of HBOT compared to the values measured before HBOT (p = 0,009). The mean ECD was 2572,53 ± 261,51 cells/mm2 before HBOT, 2554,47 ± 236,13 after the 1st session, and 2563,13 ± 226,92 after the 20th session. When the corneal properties measured before and after HBOT sessions were compared, no significant difference was found in terms of CCT, ECD, AVG, CV, and HEX (p > 0.05). Conclusion We observed no significant change in CCT, corneal endothelial layer properties, and anterior segment morphology after the 1st session, and after the 20th session of HBOT. Although HBOT reduced IOP and ACD, it was not statistically significant. HBOT may lead to a significant decrease in SE values after the 20th session.