Endothelial Cell Density Research Articles

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.

Intraoperative Performance and Early Postoperative Outcomes Following Phacoemulsification With Three Fluidic Systems: A Randomized Trial.

To compare intraoperative performance and early postoperative outcomes following phacoemulsification with two systems using active fluidics and one using gravity-based fluidics. In this prospective randomized trial, 200 eyes were randomized to the traditional and Active Sentry groups (n = 80 eyes each) where the Centurion Vision System was used with traditional or Active Sentry (Alcon Laboratories, Inc) hand-pieces, respectively, or the Infinit group (n = 40 eyes) where the Infiniti Vision System (Alcon Laboratories, Inc) was used. Within the traditional and Active Sentry groups, there were two subgroups with low (30 mm Hg) or high (55 mm Hg) intraocular pressure (IOP) used. Outcome measures compared were: cumulative dissipated energy (CDE), percentage change in central corneal thickness (CCT) at 1 day, 1 week, and 1 month, anterior chamber cells at 1 day and 1 week, rate of rise and fall of IOP following occlusion break, corneal endothelial cell density (ECD), and macular thickness 6 months postoperatively. CDE was significantly lower in group II compared to the traditional group (2.96 ± 1.4 vs 4.14 ± 2.2, P = .001). With 30 mm Hg IOP, the Active Sentry group had significantly less percentage change in CCT at 1 week postoperatively compared to the traditional handpiece group (0.01% vs 0.02%, P = .008). Incidence of anterior chamber cells less than grade 2 on day 1 was significantly higher in the Active Sentry group (82.9% vs 52%, P = .03). Percentage change in ECD was significantly lower in the Active Sentry group (-0.957 vs -0.98%, P = .005). Significantly faster rise of IOP to baseline following occlusion break was seen in the Active Sentry group. The use of Active Sentry handpiece was associated with lower CDE, less postoperative increase in CCT, fewer anterior chamber cells, and faster rise of IOP following occlusion break. [J Refract Surg. 2024;40(5):e304-e312.].

Visual function after ultrathin Descemet’s stripping automated endothelial keratoplasty or Descemet’s membrane endothelial keratoplasty combined with cataract surgery: a randomised controlled clinical trial

AimsTo compare best-corrected visual acuity (BCVA), contrast sensitivity and endothelial cell density (ECD) after ultrathin Descemet’s stripping automated endothelial keratoplasty (UT-DSAEK) and Descemet’s membrane endothelial keratoplasty (DMEK).MethodsA randomised, single-blinded, single-centre...

Ten-year follow-up of posterior chamber phakic intraocular lens with central port design in patients with low and normal vault.

To assess the clinical outcomes and postoperative complications of the implantable collamer lens (ICL) with a central port throughout 10 years of follow-up in patients with low and normal vault. Fernández-Vega Ophthalmological Institute, Oviedo, Spain. Retrospective and comparative case series. This study included eyes that underwent a V4c ICL implantation with 10 years of follow-up. The eyes were divided into 2 groups according to the vault at 1 year postoperatively: vault <250 μm and between 250 μm and 800 μm. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), intraocular pressure (IOP), endothelial cell density (ECD), vault, complications, and secondary surgeries were analyzed. 37 and 90 eyes were enrolled in the low and normal-vault groups, respectively. No differences in UDVA, CDVA, and refraction were found between the groups over 10 years of follow-up. No cases developed ICL-induced anterior subcapsular opacity over the follow-up period. 2 (5.4%) and 8 (8.9%) eyes in the low and normal-vault groups, respectively, required ICL exchange. 1 (2.8%) and 2 (2.2%) eyes in the low and normal-vault groups, respectively, required excimer laser to correct residual refractive error. The IOP remained stable throughout the 10-year follow-up. The loss in ECD from that preoperatively to 10 years postoperatively was 3.8% and 4.5% in the low and normal-vault groups, respectively ( P = .4). No pigment dispersion glaucoma or other vision-threatening complications were reported. This study shows good long-term outcomes of the V4c ICL, supporting that the central hole provides safety to the procedure and prevents the potential risk associated with low vault.

Severely subluxated cataract

A 56-year-old man with a history of myopic LASIK presented with left eye gradual blurring of vision over 3 months. There was no history of trauma. His uncorrected visual acuities were 20/25 in the right eye and 20/400 in the left eye. The right eye was normal except for an early cataract. The left eye had a moderate cataract that was phacodonetic. Vitreous was present in the shallow anterior chamber (AC) (Figure 1 JOURNAL/jcrs/04.03/02158034-202405000-00018/figure1/v/2024-04-22T135154Z/r/image-tiff ). The fundus was normal. The intraocular pressures (IOPs) were 14 mm Hg in the right eye and 20 mm Hg in the left eye. Ultrasound biomicroscopy of the anterior segment in the left eye revealed near total zonular loss with few intact zonular strands at the 6 and 10 o'clock regions (Figure 2 JOURNAL/jcrs/04.03/02158034-202405000-00018/figure2/v/2024-04-22T135154Z/r/image-tiff ). Vitreous was observed in the AC, herniating mostly from the 3 o'clock region. The endothelial cell density and optical coherence tomography (OCT) of the macular and disc in both eyes were normal. Central corneal thickness was 527 µm in the right eye and 520 µm in the left eye. Describe how you would manage this case surgically. Optical biometry had been obtained, and the axial length in both eyes was similar. Discuss how you would select the monofocal intraocular lens (IOL) diopter (D) targeted for −1.50 D if the AC depth in the left eye was 2.48 mm and in the right eye was 3.25 mm.

Abstract 1131: Delivery Of Allogeneic Mitochondria Reverses Signatures Of Endothelial Aging &amp; Senescence

Mitochondrial dysfunction is a key factor in vascular aging, including endothelial cell (EC) dysfunction. This research investigates whether introducing mitochondria from allogeneic fibroblasts into human microvascular ECs can mitigate the cellular abnormalities associated with aging. Mitochondria were transferred into ECs of different passages (p6-14) using centrifugation. Post mito-transfer, the metabolic activity, mitochondrial network (density), and the proliferative capacity of ECs were evaluated through extracellular flux analysis, confocal microscopy, and 5-ethynyl-2'-deoxyuridine incorporation (proliferation assay), respectively. Results show that compared to age matched control ECs, mito-transferred ECs exhibited no change in their oxygen consumption rates linked to mitochondrial respiration. Additionally, while early passage ECs (p6-7) had no change in glycolytic activity (compared to controls), middle (p10-11) and late passage ECs (p10-14) had considerable increases in their glycolytic activity post mito-transfer. Mitochondrial network analysis additionally revealed that the mitochondrial density of early passage ECs were unaffected by mito-transfer, while late passage ECs had enhanced mitochondrial networks, including total volume, and branching post mito-transfer. Lastly, late passage ECs demonstrated a 25% increase in proliferation after mito-transfer. These findings indicate that aging in ECs is linked to increased oxidative phosphorylation metabolism, and that mito-transfer can reduce senescence-associated oxidative glucose metabolism and enhance EC proliferation. This positions mito-transfer as a promising strategy for improve EC function in cardiovascular aging.

Association between primary angle closure glaucoma and uric acid levels in serum and aqueous humor

PurposeTo evaluate abnormalities in serum and aqueous humor uric acid (UA) levels in primary angle closure glaucoma (PACG). MethodsPatients with PACG and age-similar and gender-similar controls (patients scheduled for cataract extraction) were enrolled prospectively. Serum UA levels were determined by enzymatic colorimetry; aqueous humor UA levels by Enzyme-Linked ImmunoSorbent Assay. A t-test was used to compare UA levels between PACG patients and controls, with one-way ANOVA used to compare levels across PACG subgroups with differing disease severity. Comparisons between PACG patients and controls were adjusted for systemic and ocular confounding factors using binary logistic regression. ResultsIn all, 131 PACG patients and 112 controls were included. The serum UA level was 266 ± 69 μmol/L in the PACG group and 269 ± 73 μmol/L in the control group (p = 0.71). The aqueous humor UA level was 35.4 ± 8.2 μmol/L in the PACG group and 53.9 ± 18.6 μmol/L in the control group (p < 0.001). This difference remained significant after adjusting for age, gender, systolic blood pressure, diastolic blood pressure, body mass index, axial length, central corneal thickness, anterior chamber depth, lens thickness, white-to-white distance, corneal endothelial cell density, and serum UA level (odds ratio: 0.88, 95 % confidence interval: 0.83–0.93, p < 0.001). ConclusionAqueous humor UA levels differ between PACG patients and controls, but serum UA levels do not. This indicates that local UA plays a role in the pathogenesis of PACG, but systemic UA does not.

The Protective Effect of Rho-Associated Kinase Inhibitor Eye Drops (Ripasudil) on Corneal Endothelial Cells After Cataract Surgery: A Prospective Comparative Study.

Cataract surgery poses a risk to corneal endothelial cells. This study aimed to assess the protective effect of rho-associated kinase inhibitor eye drop (ripasudil) on corneal endothelial cells after cataract surgery over 12months. We conducted a prospective, non-randomized, non-blinded comparative study including 43 patients divided into two groups: the ripasudil group (22 patients, 23 eyes) and the control group (21 patients, 21 eyes). All patients had grade 3 nuclear cataract and underwent uneventful phacoemulsification with intraocular lens implantation. In the ripasudil group, one drop of ripasudil hydrochloride hydrate (Glanatec® ophthalmic solution 0.4%) was administered three times a day for 5days. Outcome measures included central corneal thickness (CCT) and endothelial cell density (ECD), which were evaluated preoperatively and 12months postoperatively. In the ripasudil group, the median ECD was 2398 (interquartile range [IQR] 410, 2201-2611) cells/mm2 at baseline and 2262 (IQR 298, 2195-2493) cells/mm2 at 12months postoperatively. In the control group, the median ECD was 2503 (IQR 390, 2340-2730) cells/mm2 at baseline and 2170 (IQR 324, 2049-2373) cells/mm2 at 12months postoperatively. Endothelial cell loss (ECL) was 12.8% in the control group, significantly reduced to 4.5% in the ripasudil group (p = 0.001*). CCT (p = 0.042), age (p = 0.383), sex (p = 0.944), and duration of surgery (p = 0.319) were not significant factors. No adverse effects were observed in either of the groups. Incorporating ripasudil into postoperative management could help maintain corneal endothelial cell integrity and reduce cell loss after cataract surgery, potentially decreasing the need for endothelial transplantation in patients who have undergone intraocular surgeries.

Endothelial Involvement in Monocular Mpox Keratitis: In Vivo Confocal Microscopy Approach.

The aim of this study was to describe the clinical features and endothelial involvement in a case of Mpox virus keratitis by in vivo confocal microscopy (IVCM). This is a case report. A 35-year-old man presented with redness, photophobia, pain, tearing, and a low visual acuity of 0.09 (decimal) in the left eye with a 6-week history of Mpox and corneal trauma. Previous testing of blood, interdigital skin lesions, and conjunctival and eyelid margin swabs confirmed the presence of Mpox by polymerase chain reaction. Biomicroscopy displayed superficial stromal infiltrates with a continuous but irregular epithelium. IVCM revealed the presence of pseudoguttata, loss of defined cell boundaries, infiltration of inflammatory cells in the endothelial layer, endothelial ridges, and precipitated pigmented granules, consistent with endotheliitis. After this episode, the patient had 4 reactivations, also treated with topical corticoids and oral tecovirimat 600 mg twice a day for 2 weeks. On the fourth reactivation, this treatment was extended to 4 weeks. On the last visit, the patient presented a visual acuity of 0.5 with disciform keratitis and reduced endotheliitis signs. The endothelial cell density remained normal during the follow-up (2763 ± 376 cell/mm 2 at baseline and 2795 ± 238 cell/mm 2 at the last visit). Polymegathism and pleomorphism showed altered values during the follow-up. Patients with an altered corneal epithelial barrier could suffer Mpox endotheliitis, like other DNA viruses, before disciform keratitis appears. IVCM is a useful tool for the early detection of endotheliitis and for describing its evolution, improving patient care.

Long-term dynamic changes and influencing factors of corneal morphology after multiple intravitreal injections of anti-VEGF drugs.

To observe alterations in corneal morphology caused by repeated intravitreal injections of anti-vascular endothelial growth factor (VEGF). Prospective cohort study. Seventy-seven eyes were treated with intravitreal injection of anti-VEGF from June 2021 to March 2023. There were 25 eyes of neovascular age-related macular degeneration (nAMD), 24 eyes of diabetic macular edema (DME), and 28 eyes of retinal vein occlusion (RVO). Aflibercept was used in 37 eyes and Ranibizumab was used in 40 eyes. 3 + PRN was used. Corneal endothelium and corneal thickness were measured using a corneal endothelial microscope. The data related to central corneal thickness, corneal endothelial cell density (ECD), average cell size, coefficient of variation (CV), proportion of hexagonal cells (Hex%) was collected. A comparison was also made between baseline and the dynamic changes of all indexes 1 year following the last injection. It was observed that in comparison to baseline, ECD and Hex% decreased significantly after the 3rd injection of Aflibercept and Ranibizumab. However, ECD did not decrease further and remained at the same level as after the last injection. Hex% and average cell size increased to a certain extent in comparison to the last injection. All the changes were found to be statistically significant (P < .01). After 3 injections, ECD in DME group was markedly lower than that in nAMD and RVO group, but the CV in DME group was higher than that in nAMD as well as RVO groups, and all the differences were statistically significant (P < .05). Following intravitreal anti-VEGF therapy, DME is more likely than other disorders to result in a decrease in ECD. Repeated intravitreal injections of anti-VEGF drugs can reduce the Hex% and ECD to a certain extent. After the last injection, Hex% can progressively recover, and ECD can remain stable without further declining. After injections, ECD in DME group was found to be significantly lower than that in nAMD and RVO groups, but CV in DME group was significantly higher in comparison to the other 2 groups. In patients with macular edema, repeated intravitreal injections of anti-VEGF may have certain effects on corneal morphology. Patients with diabetes mellitus in particular should pay special attention to corneal safety following repeated intravitreal injections if they have significantly reduced ECD at baseline.

Long-Term Corneal Endothelial Parameters of COVID-19 Patients With Ocular Surface Symptoms.

This study aimed to investigate the long-term effects of COVID-19 on corneal endothelial cell morphology in patients with ocular symptoms to assess possible corneal involvement in patients who recovered. The COVID-19 group included patients diagnosed and treated at Istanbul University Cerrahpasa Medical Faculty with confirmed SARS-CoV-2 infection and ocular irritation symptoms. The control group was comprised of age- and sex-matched individuals. The controls had no ocular pathologies. Noncontact specular microscopy (Konan Cell Check SL, Hyogo, Japan) was performed using the center method after 156 ± 16 days of COVID-19 diagnosis. Parameters such as endothelial cell density (ECD), hexagonality (HEX), coefficient of variation, and central corneal thickness were analyzed. Specular microscopy results of 54 COVID-19 patients with ocular irritation symptoms and 72 controls were evaluated. Ocular symptoms in COVID-19 patients included conjunctival hyperemia, foreign body sensation, tearing, ocular secretion, and chemosis. Mean (±SD) ECD was 2770 ± 31 (cells/mm 2 ) in the COVID-19 group and 2897 ± 26 in the control group, and mean (±SD) HEX was 46.52 ± 6.38 in the COVID-19 group and 58.22 ± 13.94 in the control group. COVID-19 patients exhibited significantly lower endothelial ECD and HEX levels than controls ( P = 0.003 and P < 0.001, respectively). Coefficient of variation and central corneal thickness analyses did not reach statistical significance. COVID-19 can cause long-term alterations in the corneal endothelial cells, leading to decreased ECD and HEX. Future research should focus on the long-term implications of COVID-19 on the corneal health and visual outcomes.

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.

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.

The Effect of Tobacco Smoking on Corneal Endothelium and Central Corneal Thickness

We aimed to study the impact of tobacco smoking towards central corneal thickness, morphology, and corneal endothelial cell density (ECD) in healthy subjects. This cross-sectional study recruited consecutive patients who visited the Ophthalmology Clinic, Universiti Kebangsaan Malaysia Medical Centre, from April 2017 to August 2018 who were active smokers and non-smokers. Active smokers were further divided into heavy and light smokers according to the number of pack-years smoked. The nicotine dependency level was measured using the Fagerstrom test and divided into low, moderate, and severe dependency. Non-contact specular microscopy was performed. Parameters studied included the ECD, percentage of hexagonality (HEX), coefficient of variation of cell size (COV), and central corneal thickness (CCT). A total of 84 eyes from 84 subjects were included, with 42 in the smoker and 42 in the non-smoker groups. The mean age was 38.3 ± 6.7 and 39.2 ± 10.7 years in the smoker and non-smoker groups, respectively. The mean ECD, HEX, and COV were 2783 ± 316 vs. 2877 ± 333 cells/mm2, 55.0 ± 6.7% vs. 55.0 ± 7.7% and 32.7 ± 4.4% vs. 32.2 ± 4.1% in the smoker and non-smoker group, respectively. However, none were statistically significant (p&gt;0.05). The mean CCT was also not statistically different, with 532.6 ± 30.8 μm in the smoker group and 530.5 ± 30.8 μm in the non-smoker group. No statistically significant difference was found between light and heavy smokers and addiction levels. There was a statistically significant but weak negative correlation between ECD and duration of smoking (r = -.370, p = 0.016) and a weak positive correlation between COV and number of pack-years smoked (r = .344, p = 0.025). Smoking did not significantly affect corneal ECD, cellular morphology, or CCT.

Effect of Intravitreal Aflibercept on Corneal Endothelial Cells.

To determine the effect of repeated intravitreal injections of aflibercept on the corneal endothelium in patients with diabetic macular edema (DME) and macular edema due to retinal vein occlusion (RVO). In a prospective study conducted between January 2021 and November 2023, a total of 87 treatment-naive eyes with DME and RVO were evaluated. The exclusion criteria were surgery or laser intervention during the follow-up period, contact lens wear, cataract surgery in the last 6 months, dystrophy, or other corneal condition that may cause endothelial damage. In addition to routine examinations on the day of application, we also measured the corneal endothelium using specular microscopy on the 1st, 4th and 8th day of injection. We evaluated 4 parameters: endothelial cell density (CD), hexagonality (HEX), coefficient of variability (CV) and central corneal thickness (CCT). First of all, we evaluated the entire cohort of eyes, and then divided it according to 2 criteria; the diagnosis into DME/RVO and according to the lens status into phakic/pseudophakic eyes. A total of 87 eyes of 68 patients were evaluated. The average age of the patients at the time of diagnosis was 66.8 ±9.3 years. Within the cohort 51 (59%) eyes were phakic and 36 (41%) pseudophakic. A total of 61 (70%) eyes with a diagnosis of DME were treated, and 26 (30%) with RVO. During the follow-up, there were no significant changes in the average values of CD, HEX, CV, CCT due to aflibercept treatment, either in the whole group or in subgroups according to diagnosis or lens condition. The results of this study suggest that intravitreal administration of aflibercept in patients with DME and RVO did not have an impact on corneal endothelial parameters, including CCT, HEX, CD and CV. These parameters were measured using endothelial microscopy during an 8-injection observation period.

Phacoemulsification using an active fluidics system at physiologic vs high intraocular pressure: impact on anterior and posterior segment physiology.

Evaluate the impact of high vs low intraoperative intraocular pressure (IOP) during phacoemulsification on anterior and posterior physiology. Private practice in Des Moines, Iowa. Prospective, randomized, paired-eye clinical trial of patients anticipating bilateral cataract surgery. 27 participants randomized at the time of their first cataract surgery to either low IOP or high IOP group. The subsequent cataract surgery was performed under the alternate condition. During phacoemulsification and cortex removal, IOP was maintained either at low (≤28 mm Hg) or at high (≥55 to 60 mm Hg) levels. The primary outcome was fluid usage, with secondary outcomes of central corneal thickness, foveal avascular zone area, foveal and macular thickness, endothelial cell density (ECD), and postoperative inflammation. Surgery with low IOP settings used less fluid (40.0 mL vs 55.6 mL, P < .0001). Corneal thickness changes were smaller in low IOP eyes at 1 day and 1 week (3.0% vs 8.1%, P = .01; 3.1% vs 4.4%, P = .01) but were similar by 1 and 3 months. ECD dropped less in low IOP eyes at 1 and 3 months (-1.7% vs -12.3%, P = .001, 2.1% vs -8.9%, P = .0003.) IOP remained a significant predictor of ECD change when relationship was controlled for fluid use and phacoemulsification energy. Retinal parameters did not vary among all eyes or when compared by IOP setting. Visual acuity was similar at all timepoints. Low IOP settings resulted in less inflammation and less corneal trauma, as evidenced by a smaller drop in ECD and less postoperative corneal edema, when compared with high IOP settings. Retinal parameters did not change significantly. The different outcomes did not result in a difference in visual acuity.

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.

A Shape Memory Polymeric Shield for Protecting Corneal Endothelium During Phacoemulsification.

The purpose of this study was to explore the protective effect of a shape memory polymeric shield on corneal endothelium during phacoemulsification in rabbits. Poly-(glycerol dodecanedioate) (PGD) with a transition temperature of 24.416°C was prepared to make a shape memory shield with a thickness of 100µm, an arc length of 14 mm, and a radius of curvature of 8.8 mm. In the control group, a phaco-tip with bevel-down was used to simulate injury to the corneal endothelium by phacoemulsification in rabbits. In the experimental group, the pre-cooled and curled shape memory shield was injected into and removed from the anterior chamber before and after phaco-power release. Anterior segment optical coherence tomography (AS-OCT), confocal microscope, trypan blue/alizarin red staining, and scanning electron microscope were performed to measure endothelial damage after surgery. One day postoperatively, the lost cell ratio of the control group and the experimental group were 28.08 ± 5.21% and 3.50 ± 1.43%, respectively (P < 0.0001), the damaged cell ratios were 11.83 ± 2.30% and 2.55 ± 0.52%, respectively (P < 0.0001), and the central corneal thicknesses (CCT) were 406.75 ± 16.74µm and 340. 5 ±13.48µm, respectively (P < 0.0001). Seven days postoperatively, the endothelial cell density (ECD) of the control group and the experimental group were 1674 ± 285/mm2 and 2561 ± 554/mm2, respectively (P < 0.05). The above differences were all statistically significant. This PGD based shape memory shield has a protective effect on corneal endothelium during phacoemulsification. It reduces postoperative corneal edema and ECD decrease in the short term after surgery. The shape memory PGD "shield" in this study may have a use in certain human patients with vulnerable corneas of low endothelial cell count or shallow anterior chambers.

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.

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.