The Effects of Glaucoma and Glaucoma Therapies on Corneal Endothelial Cell Density

Impact of preoperative intraocular pressure on corneal endothelial cell loss after phacoemulsification in acute primary angle-closure glaucoma with cataracts

Purpose

This study aimed to assess corneal endothelial cell loss (ECL) following phacoemulsification and intraocular lens implantation (Phaco+IOL) in eyes with acute primary angle-closure glaucoma (APACG) and cataracts under different preoperative intraocular pressure (IOP) levels.

Methods

This non-randomized controlled trial included 75 eyes from 75 patients with APACG and cataracts who underwent Phaco+IOL. All patients received pharmacotherapy and anterior chamber paracentesis before surgery and were grouped according to their preoperative IOP: the high-IOP group (IOP ≥ 25 mmHg) and the IOP-controlled group (IOP < 25 mmHg). IOP, visual outcome, endothelial cell density (ECD), hexagonality (HEX), coefficient of variation (CV), and central corneal thickness (CCT) were evaluated up to 3 months postoperatively. Baseline ECD, HEX, and CV parameters were measured in the contralateral eyes of all patients as a reference and compared with the postoperative results.

Results

The average IOP decreased from 43.2 ± 4.8 mmHg to 16.5 ± 5.8 mmHg (p < 0.001) in the high-IOP group and from 18.3 ± 4.3 mmHg to 14.3 ± 3.2 mmHg (p < 0.001) in the IOP-controlled group on the first postoperative day. The changes in IOP were more significant in the high-IOP group (p < 0.001). The ECD at 3 months was 1705.2 ± 503.8 cells/mm2 in the high-IOP group and 2091.8 ± 330.1 cells/mm2 in the IOP-controlled group (p < 0.001). The ECL rates at 3 months were 35.0% (high-IOP group) and 17.4% (IOP-controlled group) (p < 0.001). The postoperative changes in HEX and CV at 3 months were more significant in the high-IOP group (p < 0.001; p = 0.003). Both groups produced comparable improvements in visual acuity and IOP.

Conclusion

Uncontrolled high IOP (≥ 25 mmHg) before Phaco+IOL in patients with APACG and cataracts is associated with a higher rate of ECL. The rapid and substantial reduction of IOP during surgery may exacerbate corneal endothelial cell loss.

Clinical trial registration

ClinicalTrails.gov, identifier ChiCTR2100052096.

Examination of the Corneal Endothelium in Patients With Congenital Aniridia With a PAX6 Mutation Using In Vivo Confocal Laser Scanning Microscopy

PURPOSE

In PAX6 syndrome, it is still not clear, whether prenatally, parallel to the iris tissue developmental anomaly, there is neural ectodermal, neural crest, or mesodermal cell deposition at the corneal endothelium, affecting endothelial structure and function. In addition, because of the postnatal corneal inflammation and commonly appearing secondary glaucoma, progressive endothelial changes are expected. Our purpose was to study the corneal endothelium in subjects with PAX6 aniridia, using in vivo confocal laser scanning microscopy.

METHODS

Twenty-seven eyes of 16 subjects with congenital aniridia (age 28.25 ± 16.32 [11-59] years, 8 [50%] female) and 40 eyes of 26 healthy subjects (age 33.8 ± 15.2 [14-67] years, 17 [58.6%] females) were examined. Aniridia-associated keratopathy and iris malformation were graded, and means of endothelial cell density, cell area, cell diameter, spatial pattern of cell centroids (Clark-Evans index), polygonality, neighbor count, percentage of hexagonal cells, and endothelial deposit number were determined by in vivo confocal laser scanning microscopy.

RESULTS

Mean cell diameter and mean Clark-Evans index were significantly lower ( P = 0.049; P = 0.008) in congenital aniridia eyes than in controls. There were hyperreflective endothelial deposits in congenital aniridia eyes but not in controls ( P < 0.001). Only aniridia-associated keratopathy grade correlated positively with mean endothelial deposit number ( P = 0.017).

CONCLUSIONS

In congenital aniridia, the corneal endothelium might possess a slightly better quality and greater reserves than in healthy subjects. Corneal endothelial deposition seems to be independent from developmental abnormalities but may be related to up to date undescribed endothelial inflammatory or metabolic changes.

Intraoperative OCT to check the correct postimplant position of PreserfloTM

INTRODUCTION

This study was designed to examine the capacity of intraoperative optical coherence tomography (OCT) to predict the postimplant position of the glaucoma drainage device PreserfloTM.

METHODS

13 eyes (mean age 65.42 (14.89) years) underwent PreserfloTM (Santen, Osaka, Japan) placement. Before surgery, participants were subjected to a comprehensive ophthalmic examination (intraocular pressure (IOP), cup to disk ratio (C/D), visual field, OCT, endothelial cell count). Anterior segment OCT scans were obtained intraoperatively using a Rescan 700 OCT system (Carl Zeiss Meditec, Inc., Oberkochen, Germany). One day postsurgery, anterior segment OCT using the Spectralis OCT (Heidelberg Engineering GmbH) was performed in a sitting position to capture the same chamber cross-section as before. The main outcome variables were tube-endothelium distance (T-E) and tube length (TL) in the anterior chamber measured using both OCT systems. Correlation between intraoperative and office measurements was examined through Pearson correlation (r) and intraclass correlation coefficients (ICC).

RESULTS

Mean intraoperative and in-office T-E were 625.26 (SD 366.60) versus 561.16 (SD 364.62) µm respectively (p = 0.540). Intraoperative and in-office anterior chamber TL were 1386 (SD 701.82) and 1433.91 (SD 713.55) µm, respectively (p = 0.029). Excellent correlation was observed between both sets of T-E (r = 0.992; p = 0.008) and TL (r = 0.984; p = 0.016) values. Both OCT systems showed good agreement yielding ICCs of 0.992 (p < 0.001) for T-E and 0.995 (p = 0.001) for TL.

DISCUSSION

Excellent correlation was observed between our intraoperative and postoperative OCT measurements. These results support the usefulness of intraoperative OCT to confirm the correct position of an implanted PreserfloTM microshunt.

The Road Less Traveled: Ciliary Sulcus Implantation of the Preserflo MicroShunt

Introduction

Herein, we report on the option and clinical advantage of the Preserflo MicroShunt insertion into the posterior chamber ciliary sulcus in a patient with advanced pseudoexfoliation glaucoma at a high risk of corneal decompensation.

Case Presentation

We describe a 64-year-old advanced pseudoexfoliation glaucoma patient who despite maximal tolerated medical therapy and two failed glaucoma surgeries, still suffered from uncontrolled intraocular pressure (IOP) of 36 mm Hg in his left eye. The patient underwent the implantation of the Preserflo MicroShunt. The shunt was placed nasally into an area of unscarred conjunctiva, with the anterior part of the shunt inserted into the ciliary sulcus. Postoperatively, the patient's IOP dropped to 6 mm Hg on the first day and stabilized at 11 mm Hg at the 6-month mark. An elevated, posteriorly located bleb was observed, and the patient no longer required additional topical medications. Endothelial cell (EC) count remained stable with no signs of corneal edema. The patient did not experience any serious postoperative complications.

Conclusion

Implantation of the Preserflo MicroShunt into the ciliary sulcus appears to be a viable option for patients at high risk of corneal decompensation, hence, offering effective IOP control while minimizing EC loss. Further studies with larger patient groups are warranted to better evaluate the safety and efficacy of this technique.

Safety and Efficacy of STREAMLINE Canaloplasty with Phacoemulsification in Hispanic Adults with Open-Angle Glaucoma: 12-Month Outcomes

Purpose

To report the 12-month clinical outcomes in eyes with mild to moderate open-angle glaucoma (OAG) in Hispanic adults undergoing STREAMLINE Surgical System (STREAMLINE) canaloplasty combined with phacoemulsification.

Patients and Methods

This was a prospective, multi-center, interventional clinical trial involving 45 eyes of 45 Hispanic adult patients receiving topical medical therapy for mild to moderate OAG and undergoing phacoemulsification surgery for visually significant cataracts at three sites. All eyes underwent a Screening visit, followed by medication washout and a subsequent Baseline visit to determine eligibility for STREAMLINE canaloplasty. The primary outcome was the proportion of unmedicated eyes with intraocular pressure (IOP) reduction of ≥20% from Baseline at Month 12. Secondary outcomes included mean change in IOP from post-washout Baseline, mean change in IOP-lowering medications compared to pre-washout Screening, and adverse events (AEs).

Results

43 eyes met the eligibility criteria for analysis and 40 eyes completed the 12-month visit. The mean (standard deviation) age was 68.7 (8.6 years), 76.7% were female, and 72.1% of the eyes were classified as having mild OAG. The mean number of IOP-lowering medications at Screening was 1.95 (0.82). After washout, the Baseline mean IOP was 23.0 (1.8) mmHg. At Month 12, 28/40 eyes (70.0%) remained medication-free, of which 27 (96.4%) had an IOP reduction of ≥20% from Baseline. The mean IOP at Month 12 was 15.3 (2.8) mmHg, a reduction of 7.8 (3.0) mmHg from Baseline (p<0.001). The mean medication use at Month 12 was 0.63 (1.19) per eye, representing a mean reduction of 1.38 (1.03) medications from Screening (p<0.001). Device- or procedure-related ocular AEs were mostly mild in severity and self-limited.

Conclusion

STREAMLINE canaloplasty in combination with phacoemulsification provides clinically and statistically significant reduction in IOP and IOP-lowering medications in eyes with mild to moderate OAG in Hispanic adults.

Long-term efficacy and safety of ab externo canaloplasty in the Polish Caucasian population with open-angle glaucoma: A 3-year retrospective study

This study aimed to assess the effectiveness and safety of ab externo canaloplasty over a 3-year follow-up period in Polish Caucasian patients with glaucoma. This retrospective study of a cases series was conducted at the Department of Ophthalmology Medical University of Bialystok, Poland. Primary outcome measures were intraocular pressure and medication burden. Secondary outcome measures were best corrected visual acuity, retinal nerve fiber layer thickness, visual field test results, endothelial cell density, intraoperative and postoperative complications, and additional glaucoma surgery. The study group consisted of 160 eyes diagnosed with early to-moderate primary open-angle glaucoma and treated with ab externo canaloplasty from 2014 to 2020. The criteria for qualified and complete success were intraocular pressure < 18 mmHg or ≥ 20% reduction in intraocular pressure from baseline with or without antiglaucoma medications, respectively. After surgery, the mean intraocular pressure decreased from 19.23 ± 4.33 to 14.52 ± 3.79 mmHg, which constituted a 36.7 ± 7.8% reduction compared to the baseline value. The number of medications decreased by two at the end of the study period (from 2.69 ± 1.05 to 0.32 ± 0.75). Complete and qualified success were achieved in 58.7% and 68.7% of the patients, respectively, at the end of follow-up. An incomplete cannulation of Schlemm's canal was the most common intraoperative complication, occurring in 32 eyes (20%). The most frequent postoperative complications were hyphema, Descemet's membrane detachment, and a transient increase in intraocular pressure. Additional surgical procedure was required in seven cases (4.4%). In 16 patients (10%), medical treatment was re-administered. Overall, our findings suggest that ab externo canaloplasty is a good option for Polish Caucasian patients with primary open-angle glaucoma. It reduces intraocular pressure and has a low postoperative complication rate. Additional glaucoma surgery or re-administration of medications is required if the target intraocular pressure is unsatisfactory.

A Randomized Controlled Trial Comparing STREAMLINE Canaloplasty to Trabecular Micro-Bypass Stent Implantation in Primary Open-Angle Glaucoma

Purpose

To report interim results of the VENICE study, a multi-center, randomized, controlled trial (RCT) comparing STREAMLINE Surgical System (STREAMLINE) canaloplasty with iStent inject W (iStent W) implantation in patients with mild-to-moderate primary open-angle glaucoma (POAG) undergoing phacoemulsification.

Patients and Methods

Safety and efficacy analyses involving the first 72 randomized eyes are included in this report. Following pre- (Screening) and post-medication washout (Eligibility) visits, one eye per subject was randomized 1:1 to STREAMLINE or iStent W after undergoing uncomplicated phacoemulsification. Subjects were evaluated postoperatively at Day 1, Week 1, Month 1, 3, and 6. Intraocular pressure (IOP) measurements, number of IOP-lowering medications, and adverse events (AEs) were assessed at each follow-up visit.

Results

Seventy-two eyes were randomized; 35 underwent STREAMLINE canaloplasty and 37 were implanted with the iStent W. Seventy eyes completed their 6-month follow-up. Both the mean morning post-washout Baseline IOP between STREAMLINE 24.86±3.05 mmHg and iStent W 25.16±3.41 mmHg and the mean IOP at 6 months between STREAMLINE eyes 16.52±3.63 mmHg and iStent W eyes 16.08±3.19 mmHg were not statistically significantly different (p=0.691 and 0.596, respectively). At 6 months, more eyes were on zero glaucoma medications in the STREAMLINE group (81.8%) compared to the iStent W group (78.4%). In medication-free eyes, the mean IOP was reduced from 24.80±2.79 mmHg to 16.00±3.40 mmHg and 24.60±3.18 mmHg to 15.80±2.21 mmHg in the STREAMLINE and iStent W groups, respectively (p=0.752). Both groups showed reduction in IOP-lowering medications at every visit, compared to pre-washout (Screening), with STREAMLINE resulting in numerically fewer medications 0.20±0.48 compared to iStent W 0.40±0.79 at 6 months (P=0.384). AEs were mild and self-limited.

Conclusion

To our knowledge, the VENICE trial is the first RCT involving canaloplasty. These interim findings demonstrated comparable IOP and medication reduction between STREAMLINE canaloplasty and iStent W implantation, when combined with phacoemulsification.

Omidenepag Isopropyl 0.002% versus Latanoprost 0.005% in Open-Angle Glaucoma/Ocular Hypertension: The Randomized Phase III PEONY Trial

Purpose

To compare the efficacy and safety of omidenepag isopropyl (OMDI) 0.002% with latanoprost 0.005% once daily in Asian subjects with open-angle glaucoma (OAG)/ocular hypertension (OHT).

Methods

In this Phase III randomized, observer-masked, active-controlled, multinational trial (NCT02981446), subjects aged ≥18 years with OAG/OHT in both eyes and baseline intraocular pressure (IOP) ≥22 mmHg and ≤34 mmHg were randomized 1:1 to OMDI or latanoprost. IOP was measured at 9AM, 1PM, and 5PM at baseline, 1 week, 6 weeks, and 3 months. Adverse events (AEs) were recorded. Non-inferiority of OMDI to latanoprost was tested for primary and key secondary endpoints.

Results

Each group included 185 subjects. Mean diurnal IOP from baseline to month 3 was reduced 7.1 mmHg (28.8%) with OMDI and 7.8 mmHg (31.3%) with latanoprost, with the least-squares mean difference (OMDI minus latanoprost) being 0.6 mmHg (95% CI: 0.0, 1.2 mmHg; p = 0.0366), indicating non-inferiority. Mean IOP reductions at the nine timepoints were -5.8 to -7.3 mmHg (23.5-29.5%) for OMDI and -6.1 to -7.9 mmHg (24.3-31.7%) for latanoprost. Non-inferiority per FDA criteria was also met. Rates of all AEs, ocular AEs, and ocular AEs associated with treatment were 40.0%, 36.8%, and 23.2%, respectively, for OMDI and 29.7%, 21.1%, and 11.9%, respectively, for latanoprost. Conjunctival hyperemia rates were higher with OMDI than latanoprost (11.9% vs 5.4%). Most AEs were mild, with no serious ocular AEs.

Conclusion

OMDI safely and effectively reduces IOP in Asian subjects with OAG/OHT, with mean diurnal IOP at Month 3 and per-timepoint IOP reductions non-inferior to those of latanoprost.

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

BACKGROUND

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.

METHODS

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.

RESULTS

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).

CONCLUSION

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.

Analysis of cardiovascular risk factors for the viability of cornea donors: a case-control study

OBJECTIVE

The main objective of the study was to evaluate the influence of arterial hypertension, diabetes, dyslipidaemia, smoking, alcoholism and COPD (chronic obstructive pulmonary disease) on the viability of the extracted tissue as well as the donor.

DESIGN

Observational case-control study.

SETTING

Regional hospital in Northern Spain.

PARTICIPANTS

1517 corneas were registered.

INTERVENTIONS

Patients' medical history was reviewed after corneal donation and evaluation. Previous medical information (age, sex and cardiovascular risk factors (CVRFs)) and data related to the donor (type of donor), the corneal tissue and its evaluation, and the viability of the implant were collected.

RESULTS

A total of 1517 corneas were registered and 81.5% of the donors presented at least one CVRF. In relation to the viability of the donor, it was observed that having suffered from COPD reduced the viability of the donor (no COPD: 93.8% vs COPD: 88%; OR=0.49; 95% CI: 0.28 to 0.84) while alcohol consumption increased it (drinker or ex-drinker: 95.8% vs non-drinker: 92.5%; OR=1.84; 95% CI: 1.01 to 3.33). Regarding tissue viability, decreased viability was observed in the presence of COPD (no COPD: 72.5% vs COPD: 64; OR=0.67; 95% CI: 0.47 to 0.96) and diabetes mellitus (no diabetes: 72.9% vs diabetes: 67.2%; OR=0.76; 95% CI: 0.58 to 0.99). As regards the viability of the implant, a total of 1039 corneas (68.9%) were suitable, observing decreased viability when suffering from COPD (no COPD: 69.8% vs COPD: 60.7%; OR=0.67; 95% CI: 0.47 to 0.94) and increased when having an active smoking habit (no habit: 65.3% vs habit: 74.1%; OR=1.52; 95% CI: 1.21 to 1.91).

CONCLUSIONS

Through this study, it can be concluded that in the absence of absolute exclusion criteria for donors, the assessment of how CVRF, alcoholism and COPD may affect the donor provides details about the quality of the tissue to be obtained.

Preserflo MicroShunt: Efficacy and Endothelial Cell Density

PRCIS

A main safety concern associated with new glaucoma implants is corneal endothelial cell loss, which could even be observed in already established procedures.

PURPOSE

The purpose of this study was to evaluate the efficacy and corneal safety, especially corneal endothelial cell loss (ECL), after Preserflo MicroShunt implantation.

METHODS

A monocentric, prospective clinical observational study of patients with a follow-up of at least 12 months who underwent Preserflo MicroShunt implantation at the Department of Ophthalmology, University Hospital of Düsseldorf, Germany, between January 2020 and October 2021. Endothelial cell density (ECD), the distance between the tip of the implant and the corneal endothelium, and the success of the surgery were analyzed.

RESULTS

In total, 14 eyes of 12 patients were included. After a mean follow-up of 20±2.7 months intraocular pressure was significantly reduced by 8.2 mm Hg (P=0.0041); in 28.6% of patients, a revision surgery was necessary. Reduction of preoperative and follow-up ECD was not statistically significant (ECL of 45 cells/mm2, ECDpreoperative=2074±703.6 cells/mm2, ECDlast follow-up=2029±742.3 cells/mm2, P=0.42). A longer intracameral shunt tube length correlated significantly with a higher distance between the shunt tip and corneal endothelium (r=0.61, P=0.036).

CONCLUSIONS

Preserflo MicroShunt effectively lowered intraocular pressure without substantial ECL after a minimum follow-up period of 17 months.

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

PURPOSE

To analyze corneal biomechanics, specular microscopy, and optical coherence tomography-angiography findings in children with glaucoma.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Changes in corneal endothelial cell density after trabeculectomy

BACKGROUND

Glaucoma is a leading cause of blindness worldwide for which trabeculectomy is the most effective surgical intervention for advanced disease. However, trabeculectomy has been associated with alterations to corneal endothelium, including a decrease in corneal endothelial cell density (CECD). The purpose of this study was to investigate changes in CECD after trabeculectomy, and identify factors contributing to cell loss, such as pre-operative biometry and lens status.

METHODS

This retrospective study included 72 eyes of 60 patients who underwent trabeculectomy between January 2018 and June 2021 at two private hospitals. Demographic and clinical data were obtained at baseline. Corneal specular microscopy was performed pre-operatively and at 6 months after surgery. CECD was evaluated and compared between groups to quantify changes to corneal endothelium and identify significant factors affecting decreases in cell density.

RESULTS

Mean CECD was 2284.66 ± 375.59 pre-operatively and 2129.52 ± 401.96 after 6 months (p < 0.001). A greater decrease in CECD (p = 0.005) was observed in phakic eyes (235.45 ± 118.32) compared to pseudophakic eyes (137.82 ± 107.30). The amount of cell loss was negatively correlated with pre-operative central corneal thickness (p = 0.009) and anterior chamber (AC) depth (p = 0.033). There were no significant correlations between changes to CECD and patient age, gender, number of pre-operative glaucoma medications and number of post-operative antifibrotic agents.

CONCLUSIONS

Significant decreases in CECD occurred after trabeculectomy. Less corneal endothelial cell loss occurred in pseudophakic eyes. Hence, if patients need trabeculectomy and cataract surgery, it may be better to perform cataract surgery first. Longer term studies should derive more information.

Risk factors associated with corneal endothelial cell density in Posner-Schlossman syndrome

PURPOSE

To investigate the risk factors related to corneal endothelial cell density (ECD) in patients with Posner-Schlossman syndrome (PSS).

PATIENTS AND METHODS

It was an observational retrospective study. We reviewed the medical records of patients with PSS who attended the ophthalmology department at Wuhan University Zhongnan Hospital from January 2019 to December 2021. 42 eyes of 42 patients with PSS were included in the study. Demographic characteristics and clinical manifestations were recorded. The clinical characteristics of PSS patients with reduced ECD were compared with PSS patients with normal ECD. Simple and multiple linear regression analyses were carried out to identify the risk factors for ECD in PSS.

RESULTS

The ECD-lowered group had a longer disease duration (P = 0.000), higher rate of occurrence of corneal edema (P = 0.039), higher cytomegalovirus (CMV) deoxyribonucleic acid (DNA) copy number (P = 0.044), higher interleukin-10 (IL-10) level in the aqueous humor (P = 0.044), and thinner average retinal nerve fiber layer (RNFL) thickness (P = 0.016) than the control group. The results of multiple linear regression analysis indicated that disease duration (β =  - 0.287, P = 0.024) and level of IL-10 in the aqueous humor (β =  - 0.408, P = 0.001) were significantly negatively associated with ECD, while average RNFL thickness (β = 0.330, P =  0.007) was significantly positively related to ECD in PSS.

CONCLUSION

A longer disease duration, higher degree of glaucomatous damage and elevated level of IL-10 in the aqueous humor were associated with reduced ECD in PSS.

Corneal Endothelial Cell Loss in Patients After Minimally Invasive Glaucoma Surgery: Current Perspectives

Minimally invasive glaucoma surgery (MIGS) is a rapidly expanding category of surgical glaucoma treatment options that offer a superior safety profile compared with traditional approaches for reducing intraocular pressure. However, MIGS may cause corneal endothelial cell loss; therefore, it has been receiving increasing attention. This systematic review aimed to evaluate and compare the rate and degree of corneal endothelial loss after MIGS. First, this paper presents an overview of the theoretical effectiveness of MIGS, the fundamental aspects regarding the roles of endothelial cells, and the effect of cataract surgery on the quality and count of endothelial cells. Further, we detail the various surgical techniques involved in MIGS, the development of these techniques over the time, and clinical aspects to consider with respect to the endothelial cell count. We discuss in detail the COMPASS-XT study, which was based on data collected over 5 years, reported that withdrawal of the CyPass Micro-Stent (Alcon Laboratories) yielded increased corneal endothelial cell loss. Generally, MIGS procedures are considered safe, with the incidence of complications ranging from 1% to 20% depending on the surgery type; however, there is still need for studies with longer follow-up. Thus, an adequate count of endothelial cells in the central cornea portion is recommended as necessary for candidate patients for MIGS.

Interim Analysis of STREAMLINE® Surgical System Clinical Outcomes in Eyes with Glaucoma

Purpose

To characterize the clinical outcomes of a novel ab interno minimally invasive procedure with the STREAMLINE^® Surgical System for creation of incisional goniotomies and canal of Schlemm viscodilation in eyes with mild to severe primary open-angle glaucoma (POAG).

Methods

In a prospective, single-arm, first-in-human case series, 20 eyes of 20 subjects with mild to severe POAG underwent creation of incisional goniotomies and canal of Schlemm viscodilation following phacoemulsification cataract extraction after washout of all intraocular pressure (IOP)-lowering medications. The angle surgery portion was performed with a single-use handpiece tipped with a microcannula that creates precise goniotomies through the trabecular meshwork into the canal of Schlemm and delivers a small volume of ophthalmic viscosurgical device directly into the canal via precise catheterization. Outcomes in this interim analysis included mean reduction in IOP and medications through 6 months of follow-up, as well as the proportion of eyes achieving IOP reduction ≥20% from baseline.

Results

At month 6, mean IOP reduction of ≥20% from baseline was achieved in 89.5% of eyes (17/19). Mean (standard deviation) medicated IOP at screening was 16.3 (3.6) mmHg and unmedicated baseline IOP (after washout) was 23.5 (2.5) mmHg. Mean IOP was significantly reduced from baseline through 6 months of follow-up to 14.7 (2.4) mmHg (p<0.001), representing an IOP reduction of 8.8 mmHg (36.9%). Overall, 57.9% (11/19) of eyes decreased dependence on IOP-lowering medications by at least one medication, and 42.1% (8/19) were medication free. Mean medication use was reduced from 2.0 (0.8) at screening to 1.1 (1.1) at 6 months (p<0.001). Three eyes had transient IOP spikes treated with topical medications.

Conclusion

The creation of incisional goniotomies and canal of Schlemm viscodilation safely and effectively reduced IOP and the need for IOP-lowering medications by both clinically and statistically significant magnitudes in eyes with mild to severe POAG undergoing concomitant phacoemulsification cataract extraction through the first 6 months of follow-up.

Twenty-Four-Month Outcome of Gonioscopy-Assisted Transluminal Trabeculotomy (GATT) in Eyes With Prior Corneal Transplant Surgery

PURPOSE

Glaucoma is a well-known sequelae of corneal transplant surgery and is a leading cause of visual loss in this patient group. We evaluated the performance and safety of gonioscopy-assisted transluminal trabeculotomy (GATT) in this population.

DESIGN

Noncomparative retrospective case series.

PARTICIPANTS

Consecutive eyes of patients receiving the GATT procedure for uncontrolled intraocular pressure (IOP) following corneal transplant surgery from 2016 to 2019.

METHODS

Retrospective analysis of eyes with a history of prior corneal transplant undergoing GATT at Glaucoma Associates of Texas between 2016 and 2019 was performed. Data included IOP, patient demographics, preoperative and postoperative medications, preoperative and postoperative corneal procedures, complications, and need for reoperation for IOP control.

MAIN OUTCOME MEASURES

IOP reduction and medication use following the procedure.

RESULTS

Thirty-nine eyes of 32 patients with prior corneal transplant surgery underwent a GATT procedure. Prior corneal surgery included penetrating keratoplasty (59.0%), Descemet's stripping endothelial keratoplasty (35.9%), Descemet's membrane endothelial keratoplasty (2.6%), and deep anterior lamellar keratoplasty (2.6%). Patient age ranged from 24 to 94 years (mean 68.0 y) with 44% female and 81% Caucasian. The majority of patients had secondary open angle glaucoma (64.1%). There was a significant reduction in IOP and number of medications at all postoperative time points after censoring patients requiring reoperation to control IOP (P<0.001). At 24 months the pressure decreased from baseline of 30.9±11.5 to 13.9±4.7 mm Hg. Medications decreased from 4.2±1.0 medications at baseline to 0.6±1.0 at 24 months. Visual acuities decreased significantly over the first postsurgical month (all P<0.05), but these recovered at subsequent follow-up visits with 2-Snellen line improvements exceeding losses from month 3 to 36. Seven eyes required reoperation for uncontrolled glaucoma at a median of 8.5 months (range: 1.6 to 16.2 mo) after GATT. The cumulative proportion of eyes undergoing repeat cornea surgery was 2.6%, 2.6%, and 14.3% at 12, 24, and 36 months post-GATT, respectively.

CONCLUSIONS

This case series describes a group of glaucoma patients, with a history of prior corneal surgery, that were safely and successfully treated with GATT. While classically traditional glaucoma surgeries are considered the standard of care for eyes following corneal transplant surgery, GATT should be considered as a reasonable, safe and effective alternative for surgically lowering IOP.

Risk factors for fluctuations in corneal endothelial cell density (Review)

The cornea is a transparent, avascular and abundantly innervated tissue through which light rays are transmitted to the retina. The innermost layer of the cornea, also known as the endothelium, consists of a single layer of polygonal endothelial cells that serve an important role in preserving corneal transparency and hydration. The average corneal endothelial cell density (ECD) is the highest at birth (~3,000 cells/mm²), which then decrease to ~2,500 cells/mm² at adulthood. These endothelial cells have limited regenerative potential and the minimum (critical) ECD required to maintain the pumping function of the endothelium is 400-500 cells/mm². ECD < the critical value can result in decreased corneal transparency, development of corneal edema and reduced visual acuity. The condition of the corneal endothelium can be influenced by a number of factors, including systemic diseases, such as diabetes or atherosclerosis, eye diseases, such as uveitis or dry eye disease (DED) and therapeutic ophthalmological interventions. The aim of the present article is to review the impact of the most common systemic disorders (pseudoexfoliation syndrome, diabetes mellitus, cardiovascular disease), eye diseases (DED, uveitis, glaucoma, intraocular lens dislocation) and widely performed ophthalmic interventions (cataract surgery, intraocular pressure-lowering surgeries) on corneal ECD.

The effects of acute angle closure crisis on corneal endothelial cells in patients with type 2 diabetes mellitus

OBJECTIVE

This study investigated the effects of acute angle closure crisis (AACC) on the corneal endothelial cells in patients with type 2 diabetes mellitus (DM) to identify the factors that cause corneal endothelial cell injury.

METHODS

We examined 154 patients who visited Qingdao Eye Hospital for AACC in one eye (154 eyes; 28 men and 126 women; mean age of 68 ± 8 years). We divided the participants into non-DM, DM well-control, and DM poor-control groups, with the unaffected eyes used as controls. Each participant was evaluated at the hospital while under AACC. We measured the relevant index and corneal parameters of the participants for statistical analysis.

RESULTS

There were significant statistical differences in corneal parameters among the three groups. The decreased levels of central endothelial cell density (CD) and the percentage of hexagonal cells (6A) were statistically relevant among the groups (P<0.05). The AACC duration was correlated with CD loss rate among the groups (P<0.05). The DM duration was correlated with CD loss rate in the DM well-control group. Compared with the non-DM group, the level of 6A decreased more significantly in the DM group after AACC (P<0.05). The AACC duration in the DM well-control group was significantly shorter than in the non-DM and DM poor-control groups (P<0.001). The DM poor-control group showed significantly worse visual acuity when compared with the other groups (P<0.05).

CONCLUSIONS

DM may impact the functional status of corneal endothelial cells. AACC can worsen the corneal endothelium damage in patients with DM. Blood glucose levels and the duration of intraocular hypertension are closely related to the severity of corneal endothelial injury.

Corneal Endothelial Cell Loss After PRESERFLO™ MicroShunt Implantation in the Anterior Chamber: Anterior Segment OCT Tube Location as a Risk Factor

INTRODUCTION

To analyze the effects of PRESERFLO on corneal endothelial cell density (ECD).

METHODS

Forty-six eyes that underwent PRESERFLO implantation were followed up for 12 months. Specular microscopy was performed preoperatively and at 1, 3, 6, and 12 months postoperatively to measure central ECD and mean monthly reduction (MMR). Anterior segment optical coherence tomography (AS-OCT) was applied to measure the tube-endothelium (TE < 200 μm, 201-500 μm, > 500 μm) distance. The relationship between TE distance and ECD was analyzed with a linear mixed-effects model.

RESULTS

Central ECD decreased significantly at 1 year (7.4%, p = 0.04), with an MMR of -15 ± 25 cells/mm². Regarding TE distance groups, there was an 18% ECD reduction in the < 200 μm group vs. 1% in the > 500 μm group (p = 0.08). Endothelial cell loss was related to TE distance (mean 482.9 ± 238 μm), with a higher rate at 1 month in comparison to 12 months for the same tube position in the anterior chamber (-174.8 ± 65.2 cells/mm² at 1 month vs. 30.2 ± 11.3 cells/mm² at 12 months, p < 0.01). From month 6, tubes located > 600 μm from the endothelium showed EC loss close to zero.

CONCLUSIONS

The PRESERFLO implant is associated with a loss of EC from the immediate postoperative period that continues over time at lower rates. A shorter TE distance appears to cause more severe ECD loss.

Evaluation of the Effect of the First Generation iStent on Corneal Endothelial Cell Loss-A Match Case-Control Study

Glaucoma is the leading cause of irreversible blindness worldwide. The only proven factor in slowing the progression of glaucomatous neuropathy is lower intraocular pressure (IOP), which can be achieved with pharmacology, laser therapy, or surgery. However, these treatments are associated with various adverse effects, including corneal endothelial cell loss (CECL). In recent years, several novel surgeries for reducing the IOP, collectively referred to as minimally invasive glaucoma surgery (MIGS), have been developed, one of which is the iStent. However, the long-term effects of such surgeries remain unknown. We compared a group of patients with open-angle glaucoma and cataract who underwent phacoemulsification alone with a group of patients with similar demographic and clinical characteristics who underwent simultaneous phacoemulsification and iStent implantation. Overall, 26 eyes of 22 subjects who underwent a combined phacoemulsification-iStent procedure and 26 eyes of 24 subjects who underwent cataract surgery were included. Before surgery, endothelial cells accounted to 2228.65 ± 474.99 in iStent group and 2253.96 ± 404.76 in the control group (p = 0.836). After surgery, their number declined to 1389.77 ± 433.26 and 1475.31 ± 556.45, respectively (p = 0.509). There was no statistically significant difference in CECL between the two groups 18–24 months after surgery, despite increased manipulation in the anterior chamber and the presence of an implant in the trabecular meshwork in those with an iStent implant. Thus, iStent bypass implantation is a safe treatment in terms of CECL for mild-to-moderate open-angle glaucoma.