Evaluation of the endothelial cell density and the central corneal thickness in pseudoexfoliation syndrome and pseudoexfoliation glaucoma

The Short-Term Effect of 1% Tropicamide Drop on Pupillary Diameter and Intraocular Pressure Change in Patients With Pseudoexfoliation Material

PRCIS

In this study, in patients with pseudoexfoliation syndrome (PXS) or glaucoma, changes in intraocular pressure (IOP) and pupil size after 1% tropicamide used for pupil dilation, compared with healthy patients were quantitatively demonstrated up to 4 hours after dilation.

PURPOSE

The purpose of this study was to evaluate pharmacological dilatation with one drop of 1% tropicamide on pupillary diameter and IOP changes in patients with PXS and glaucoma (PXG).

MATERIALS AND METHODS

Eighty-two patients with PXS, 78 Patients with PXG, and 35 healthy subjects were included in the study. PXG and PXS were diagnosed based on IOP assessment, corneal pachymetry, optic disc examination, visual field testing, and peripapillary retinal nerve fiber analysis. IOP and the diameter of pupil size were measured before dilatation and at postdilatation first, second, and fourth hours.

RESULTS

The mean pupillary diameter values at postdilatation second and fourth hours were statistically significantly different between the patients with PXS and PXG ( P <0.001, for each). Also, there were significant differences between the PXS group and the control group in terms of the mean pupillary diameter values at predilatation and postdilatation at the first hour and postdilatation second hour ( P =0.007, <0.001, respectively). The mean pupillary diameter at all times was statistically significantly different between PXG and control groups ( P <0.001 for each). Significant IOP increases were observed in all groups after dilatation. The mean IOP at predilatation and postdilatation fourth hour was statistically significantly different between PXG and PXS groups ( P =0.042, <0.001, respectively). Whereas the mean IOP at predilatation, postdilatation first hour, postdilatation second hour, and postdilatation fourth hour were statistically significantly different between PXG and control group ( P <0.001 for each).

CONCLUSIONS

Significant IOP increases have been observed in our study with 1% tropicamide in the PXG and PXS groups, with the peak effect at the second hour in the postdilatation period. Furthermore, the mean pupil diameter was found to be significantly lower in PXG patients compared with the control group.

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

PURPOSE

This study aimed to investigate anterior segment parameters in patients with exfoliation syndrome (XFS) and exfoliation glaucoma (XFG).

METHODS

The study adopted a retrospective case series design, involving a total of 56 patients (112 eyes) with unrelated XFS/XFG (XFS: 26 patients/60 eyes; XFG: 30 patients/44 eyes) and 100 age-related cataract cases as the control group (200 eyes). The participants were evaluated at the ophthalmology department of the First Affiliated Hospital of Xinjiang Medical University. Clinical data, including eye axial length, anterior chamber depth, white-to-white distance, central corneal thickness, and corneal endothelial cell density (ECD), were collected for statistical analysis.

RESULTS

ECD exhibited a significant difference between the XFS/XFG and age-related cataract groups (P < 0.001), while the remaining indexes did not show statistical differences (P > 0.05). Ocular parameters in patients with XFS and XFG were distinct from those in age-related cataract cases, with consistent results. Notably, there were no statistically significant differences between XFS and XFG patients.

CONCLUSIONS

ECD is reduced in XFS/XFG patients compared with age-related cataract subjects. It is crucial to remain vigilant to enhance surgical safety in XFS/XFG patients and prevent complications proactively.

Comparison of corneal, endothelial, and anterior segment parameters in eyes with and without pigment dispersion

BACKGROUND

To evaluate the differences of central corneal thickness (CCT), corneal endothelial cell morphology, and biometric parameters of the anterior chamber and iridocorneal angle in pigment dispersion syndrome (PDS), pigmentary glaucoma (PG), primary open-angle glaucoma (POAG), and healthy group.

METHODS

Twenty- three eyes in the PDS group, 39 eyes in the PG group, 33 eyes in the POAG group, and 45 eyes in the healthy control group were included in this cross-sectional retrospective study. Corneal endothelial cell density, the coefficient of variation in the cell area, hexagonality, and central corneal thickness (CCT) were obtained by specular microscopy (CEM 530, NIDEK, Japan). Anterior chamber depth (ACD), iridocorneal angle parameters and CCT were measured by anterior segment optical coherence tomography (AS-OCT) (Visante OCT, Carl Zeiss AG, Germany).

RESULTS

The mean CCT via specular microscopy (SM-CCT) was measured at the thinnest value in the PG group (531.20 ± 34.91 µm) and the thickest in the control group (569.13 ± 37.52 µm). CV value was higher in PG (34.65 ± 6.84) and POAG group (34.27 ± 9.93) and lower in control group (28.82 ± 5.18) (p = 0,005). The mean AS-OCT-CCT was the thinnest in the PG group (513.61 ± 39.94 µm), and the thickest in the control group (547.04 ± 36.72 µm) (p = 0.001). All parameters of the iridocorneal angle were larger in the PDS and PG groups (p < 0.001). In the correlation analysis of the glaucomatous eyes, a negative correlation between the C/D ratio and SM-CCT and AS-OCT-CCT (p = 0.037, p = 0.017, respectively) and a positive correlation between the pRNFL thickness and AS-OCT- CCT (p = 0.002).

CONCLUSION

CCT values obtained with both SM and AS-OCT were found to be significantly thinner in PG cases. CV, which is the measure of polymegatism, was found to be significantly higher in PG cases.

Exploring association between pseudoexfoliation syndrome and ocular aging

PURPOSE

Within a population-based follow-up study, to examine the 10-year incidence of pseudoexfoliation syndrome (PEX), possible risk factors for PEX and its association with ocular aging of the cornea, lens and retina.

METHODS

The baseline examination was conducted in 2006 on a random sample of 1,033 adult participants from Kaunas city (Lithuania) population of whom 631 had ophthalmic examination data at attendance of the 10-year follow-up in 2016. Detailed examination of the anterior and posterior segment of the eye was carried out. After diagnostic mydriasis PEX was diagnosed by the presence of typical grayish-white exfoliation material on the anterior capsule surface of the lens. The participants were divided to PEX and non-PEX groups.

RESULTS

PEX prevalence increased from 9.8 to 34.2% from baseline to 10-year follow-up. Nuclear cataract was common both in the PEX group (66.7%) and in those without PEX (72.2%), but this difference did not reach statistically significantly increased risk of developing cataract in those with PEX (OR 1.2; p = 0.61). Central corneal thickness (CCT) was thinner in the PEX group (529 ± 34 μm) and in the oldest group (525 ± 36 μm) (p < 0.001). Compared to baseline, corneal curvature (CC) became flatter in both groups (7.6 ± 0.27 vs 7.7 ± 0.26 mm; p < 0.001) during the follow-up, but the difference did not reach significance between groups. Corneal astigmatism was most commonly with-the-rule in both groups (37 (50.0%) vs 148 (68.5%); p > 0.05). Age, sex and PEX had no influence on age-related macular degeneration distribution.

CONCLUSION

The prevalence of PEX increased significantly with age in our population, with those with PEX having thinner and flatter corneae, but no difference in cataract and age-related macular degeneration characteristics.

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.

Corneal Endothelial Cell Loss in Glaucoma and Glaucoma Surgery and the Utility of Management with Descemet Membrane Endothelial Keratoplasty (DMEK)

The corneal endothelium has a crucial role in maintaining a clear and healthy cornea. Corneal endothelial cell loss occurs naturally with age; however, a diagnosis of glaucoma and surgical intervention for glaucoma can exacerbate a decline in cell number and impairment in morphology. In glaucoma, the mechanisms for this are not well understood and this accelerated cell loss can result in corneal decompensation. Given the high prevalence of glaucoma worldwide, this review aims to explore the abnormalities observed in the corneal endothelium in differing glaucoma phenotypes and glaucoma therapies (medical or surgical including with new generation microinvasive glaucoma surgeries). Descemet membrane endothelial keratoplasty (DMEK) is increasingly being used to manage corneal endothelial failure for glaucoma patients and we aim to review the recent literature evaluating the use of this technique in this clinical scenario.

Swept Source Optical Coherence Tomography Analysis of a Selected Eye's Anterior Segment Parameters in Patients with Pseudoexfoliation Syndrome

Background: Pseudoexfoliation syndrome (PEX) is a systemic, age-related disorder characterized by the production and accumulation of pseudoexfoliation material. To date, detailed characteristics have not been published regarding the iridocorneal angle and cornea in patients with pseudoexfoliation syndrome determined through swept source optical coherence tomography (SS-OCT). Methods: A total of 150 eyes of patients with pseudoexfoliation syndrome (ages 69–86 years) and 166 eyes in a control group (ages 54–79 years) were analyzed. Results: The central corneal thickness in the PEX group was 549.56 μm and was slightly (insignificantly) higher than that of the control group (540.56 µm). The anterior chamber of the eye was visibly shallower in patients with PEX syndrome than in those of the control group (2.49 mm vs. 3.07 mm; p < 0.001). The Fourier analysis parameters of the cornea showed multiple differences between the PEX and control groups. With respect to iris area, the parameters showed statistically significant differences between the PEX and control groups in all four quadrants of the eye. No statistical significance was found in the PEX group for the iridocorneal angle parameters, or corneal and lens parameters depending on gender and age. Conclusions: PEX syndrome is characterized by a significant impact on the anterior eye segment, including higher anterior and posterior keratometric values, lower anterior chamber depth, higher iris thickness, and narrower angle parameters. The characteristic anterior eye segment features of PEX syndrome can be detected using SS-OCT, which could potentially assist clinicians in properly managing the disease.

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.

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.

Endothelial Cell Density After XEN Implant Surgery: Short-term Data From the Italian XEN Glaucoma Treatment Registry (XEN-GTR)

PRECIS

XEN implant was associated with low endothelial cell density (ECD) reduction. In fact, when combined with phacoemulsification, the reduction in ECD was similar to that expected after phacoemulsification alone.

PURPOSE

The purpose of this study was to assess the impact of XEN implant, either alone or in combination with phacoemulsification, on ECD.

METHODS

Multicenter, prospective, observational study conducted on consecutive open-angle glaucoma patients, who were enrolled in the Italian XEN Glaucoma Treatment Registry and have complete endothelial cell count data at baseline and at 6 months after implantation. The primary endpoint was the mean percentage change in ECD between baseline and month 6.

RESULTS

The study included 108 open-angle glaucoma eyes (68 in the XEN-solo and 40 eyes in the XEN+phaco groups) and 60 control eyes (phaco-solo group). As compared with baseline, mean (95% confidence interval, CI) ECD reduction was -5.6% (-7.0% to -4.9%), -11.3% (-13.8% to -10.9%), and -13.0% (14.8% to -11.8%) in the XEN-solo, XEN+phaco, and phaco-solo groups, respectively (P=0.0004, <0.0001, and <0.0001, respectively). As compared with the XEN-solo group, the ECD reduction was significantly greater in the XEN+phaco group (mean difference=5.7%; 95% CI: 4.1%-7.3%, P<0.0001) and in the phaco-solo group (mean difference=7.4%; 95% CI: 5.7%-9.1%, P<0.0001). ECD reduction was similar in XEN+phaco and phaco-solo groups (P=0.9). In absolute terms, ECD reduction was significantly greater in the XEN+phaco (mean difference=169±306, P=0.021) and in the phaco-solo (mean difference=192±302, P=0.0022) groups than in the XEN-solo group.

CONCLUSIONS

The mean ECD reduction 6 months after XEN implantation was low. The ECD reduction in the XEN+phaco group was larger than in the XEN-solo group but was similar to that observed in the phaco-solo group.

Surgical Management of Pseudoexfoliative Glaucoma: A Review of Current Clinical Considerations and Surgical Outcomes

INTRODUCTION

Pseudoexfoliative glaucoma (PEXG) is the most common cause of secondary open-angle glaucoma worldwide. It is more aggressive and often more resistant to conventional treatments than primary open-angle glaucoma, yet there is currently no clear consensus on best management practices. This review explores current literature on PEXG to assess the safety and efficacy of currently available surgical techniques, and discusses clinical considerations on the diagnosis and management of the disease.

METHODS

A PubMed and Google Scholar search identified 2271 articles. These were reviewed to exclude irrelevant or duplicate data. A total of 47 studies reporting specifically on PEXG were retained and analyzed.

REVIEW

One of the most significant ophthalmic consequences of pseudoexfoliative (PEX) syndrome is the compromising of the blood-aqueous barrier resulting in the leakage of inflammatory cytokines and extracellular matrix material into the anterior chamber. Considering the high risk of developing PEXG and the aggressive nature of this type of glaucoma, accurate and timely diagnosis of PEX is critical. Therefore, systematic attentive examination for PEX deposits is crucial. Patients diagnosed with PEX need frequent glaucoma assessments. Patient information is key to improving compliance. Gonioscopy and diurnal tension curves or 24-hour intraocular pressure (IOP) monitoring are integral part of the diagnostic work-up and risk-assessment of PEXG. Because of the lability of IOP in PEX, clinical decisions on the basis of single IOP measurements should be avoided. Cataract extraction was shown to provide persistent IOP-lowering effect in the order of 10% in PEXG. A number of other surgical options may offer wider IOP reduction, and both XEN 45 gel stents and angle-based glaucoma procedures were suggested to achieve better outcomes in PEXG than in primary open-angle glaucoma. Yet, more significant IOP reductions may be achieved with filtering surgery or glaucoma drainage device. Same day postoperative IOP monitoring is recommended to treat the frequent IOP spikes following surgery, and more aggressive anti-inflammatory therapy may reduce the rates of postoperative adverse events in PEXG.

CONCLUSION

Specific studies of the surgical management of PEXG remain scarce in the medical literature, and more long-term and comparative studies are warranted to define more robust recommendations.

Corneal endothelial status in different grades of late spontaneous in-the-bag IOL dislocation

PURPOSE

 To evaluate corneal endothelial cell density (ECD) in the eyes with different grades of late spontaneous in-the-bag intraocular lens (IOL) dislocation.

METHODS

 A prospective study included seventy-eight patients who applied for IOL dislocation. Overall 80 eyes were divided into four grades based on the in-the-bag IOL dislocation classification. All eyes underwent a complete ophthalmological examination. ECD was evaluated using in vivo corneal confocal microscopy.

RESULTS

 Median corneal ECD was 1929 (1022-2958) cells/mm2 of all the patients. The lowest number of ECD was in grade 2 (grade 1 median ECD 1990.33 (1182-2425.33) cells/mm2, grade 2-1577.0 (1022-2958) cells/mm2, grade 3-2205.84 (1259-2807.67) cells/mm2 and grade 4-2072.17 (1045-2581.0) cells/mm2). A statistically significant difference was observed between the median of ECD of grade 2nd and 3rd (p = 0.023). By grouping cases into those with and without glaucoma, we found that corneal ECD was significantly lower in eyes with glaucoma compared with eyes without glaucoma in grades 3 and 4 (p < 0.05), while in other grades, the difference did not reach the significance level. We divided the corneal ECD of all eyes into two categories ≤ 1500 cells/mm2 and  > 1500 cells/mm2. Logistic regression demonstrated that the odds of having corneal ECD less than 1500 cells/mm2 increased by 3.5-fold if patients with IOL dislocation had been diagnosed with glaucoma previously.

CONCLUSION

 Late spontaneous in-the-bag IOL dislocation reduced corneal ECD. Previously diagnosed glaucoma was the most common comorbidity. This condition has a significant impact on corneal ECD for patients with IOL dislocation.

Matrix metalloproteinases and their inhibitors in Fuchs endothelial corneal dystrophy

Fuchs endothelial corneal dystrophy (FECD) is characterized by a progressive loss of corneal endothelial cells (CECs) and an abnormal accumulation of extracellular matrix in Descemet's membrane leading to increased thickness and formation of excrescences called guttae. Extracellular matrix homeostasis is modulated by an equilibrium between matrix metalloproteinases (MMPs) and their endogenous tissue inhibitors (TIMPs). This study aimed to investigate MMPs and TIMPs profile in FECD, taking into account cell morphology. Populations of FECD and healthy CECs were cultured and their conditioned media collected for analysis. The presence of proteases in the conditioned media was studied using a semi-quantitative proteome profiler array, and MMPs levels were assessed using quantitative assays (ELISA and quantitative antibody array). MMP activity was determined by zymography and fluorometry. The expression pattern of the membrane type 1-MMP (MT1-MMP, also known as MMP-14) was examined by immunofluorescence on ex vivo FECD and healthy explants of CECs attached to Descemet's membrane. Finally, MMPs and TIMPs protein expression was compared to gene expression obtained from previously collected data. FECD and healthy CEC populations generated cultures of endothelial, intermediate, and fibroblastic-like morphology. Various MMPs (MMP-1, -2, -3, -7, -8, -9, -10, and -12) and TIMPs (TIMP-1 to -4) were detected in both FECD and healthy CECs culture supernatants. Quantitative assays revealed a decrease in MMP-2 and MMP-10 among FECD samples. Both these MMPs can degrade the main extracellular matrix components forming guttae (fibronectin, laminin, collagen IV). Moreover, MMPs/TIMPs ratio was also decreased among FECD cell populations. Activity assays showed greater MMPs/Pro-MMPs proportions for MMP-2 and MMP-10 in FECD cell populations, although overall activities were similar. Moreover, the analysis according to cell morphology revealed among healthy CECs, both increased (MMP-3 and -13) and decreased (MMP-1, -9, -10, and -12) MMPs proteins along with increased MMPs activity (MMP-2, -3, -9, and -10) in the fibroblastic-like subgroup when compared to the endothelial subgroup. However, FECD CECs did not show similar behaviors between the different morphology subgroups. Immunostaining of MT1-MMP on ex vivo FECD and healthy explants revealed a redistribution of MT1-MMP around guttae in FECD explants. At the transcriptional level, no statistically significant differences were detected, but cultured FECD cells had a 12.2-fold increase in MMP1 and a 4.7-fold increase in TIMP3. These results collectively indicate different, and perhaps pathological, MMPs and TIMPs profile in FECD CECs compared to healthy CECs. This is an important finding suggesting the implication of MMPs and TIMPs in FECD pathophysiology.

Corneal endothelial cell loss following cataract surgery in patients with pseudoexfoliation syndrome: a 2-year prospective comparative study

PURPOSE

To compare the corneal endothelial cell density (ECD) before and after cataract surgery in patients with and without pseudoexfoliation syndrome (PEX).

METHODS

In this prospective study, we compared the ECD in 62 PEX patients with 62 patients without PEX (controls). The mean age was 78.3 ± 6.2 years and 77.2 ± 5.9 years, respectively. Patients were examined before and at 6 months, 1 year and 2 years after cataract surgery. The corneal endothelium was examined with confocal microscopy, and the ECD was counted both automatically and semi-manually. Nine patients in the PEX group (15%) and 11 patients in the control group (18%) were lost to follow-up in the 2-year period. Within the PEX and the control groups, we also compared the ECD between patients with and without glaucoma.

RESULTS

Before surgery, the ECD (semi-manual counting) was 2258 ± 342 cells/mm² in the PEX group and 2322 ± 321 cells/mm² in the control group (p = 0.29). There were no significant differences in postoperative ECD between these groups at any visit. After 2 years, the ECD had changed by -679 ± 337 cells/mm² and -704 ± 484 cells/mm² , respectively (p = 0.78). The preoperative ECD was lower in eyes with glaucoma compared to eyes without glaucoma, both within the PEX group (p = 0.05) and the control group (p = 0.03). After surgery, there were no differences between eyes with or without glaucoma.

CONCLUSION

The ECD was not significantly different in PEX eyes compared with control eyes, neither before nor after cataract surgery. However, there seemed to be a lower ECD in eyes with glaucoma before surgery.

Monitoring and management of the patient with pseudoexfoliation syndrome: current perspectives

Pseudoexfoliation syndrome (PES) is a complex and age-related systemic disorder characterized by the progressive accumulation and granular deposition of pseudoexfoliative material in various intraocular and extraocular tissues. The diagnosis of PES is so important because it is a major risk factor for complications during cataract surgery and the most frequent cause of secondary glaucoma. In addition to ocular complications, PES is related with numerous systemic abnormalities, for which the list is growing steadily. Therefore, management and monitoring of patients with PES are crucial. The aim of this paper was to review current perspectives on monitoring patients with PES and addressing management of ocular and systemic associations of this clinically important and biologically fascinating disease.

Morphological features of the corneal endothelium in patients with pseudoexfoliative glaucoma

Purpose. To study the main morphological features of the corneal endothelium in patients with pseudoexfoliative glaucoma (PEG). Methods. We included 193 subjects aged from 55 to 75 years. The main study group (PEG) included 96 patients (192 eyes), the primary open angle glaucoma (POAG) group included 36 patients (72 eyes) with POAG, the PEX group included 31 patients (62 eyes) with pseudoexfoliation syndrome without glaucoma. The control group consisted of 30 healthy subjects (60 eyes). Main corneal endothelium parameters were evaluated using a non-contact endothelial microscope EM-935 (Haag Streit, Switzerland). Data were analyzed by STATISTICA 9 software for Windows. Results. The patients with PEG had lower endothelial cell density (ECD) in comparison to the control group (p < 0.01), and PEX group (p < 0.05). The polymegatism level in patients with PEG and POAG was higher than in the control group (p < 0.001, and p < 0.01, correspondingly). In patients with moderate and advanced PEG, the ECD was significantly lower (p < 0.01), and the polymegatism level was significantly higher (p < 0.01) than the same parameters in patients with early PEG. The lowest ECD and the highest polymegatism percentage were observed in PEG patients with more pronounced PEX manifestations, p < 0.05. No effect of IOP-lowering eye drops on the corneal endothelium parameters was revealed, p < 0.05. Conclusions. Significant morphological changes of the corneal endothelium (decreased endothelial cell density, increased polymegatism percentage) were revealed in patients with PEG. It was established that the severity of these changes is associated with the PEG and PEX severity. No effect of IOP-lowering eye drops on the corneal endothelium parameters was detected.

Prospective cohort study of corneal endothelial cell loss after Baerveldt glaucoma implantation

Purpose

To evaluate corneal endothelial cell loss after Baerveldt glaucoma implantation.

Methods

We prospectively evaluated changes in endothelial cell density (ECD) in the cornea of 59 patients (59 eyes) who underwent Baerveldt glaucoma implantation. Tubes were inserted into the anterior chamber in 45 eyes and pars plana in 14 eyes. The primary outcome measure was the change in corneal ECD after Baerveldt glaucoma implantation. Secondary outcome measures included relationships between corneal ECD and optical coherence tomography images of tube parameters (tube–cornea distance and tube–cornea angle) and prognostic factors for corneal ECD loss.

Results

Corneal ECD decreased significantly by 9.2% at 12 months after surgery (P = 0.001). In the anterior chamber Baerveldt glaucoma implantation group, corneal ECD at the tube insertion quadrant decreased significantly by 9.6% at 3 months (P = <0.001), 10.7% at 6 months (P = <0.001), and 13.1% at 12 months (P = <0.001). Corneal ECD at the center decreased significantly at 6 months after surgery (7.2% loss; P = 0.012) and at 12 months after surgery (12.1% loss; P = 0.001). Corneal ECD at the contralateral quadrant decreased significantly at 12 months after surgery only (10.3% loss; P = 0.004). In the pars plana Baerveldt glaucoma implantation group, no significant loss of corneal ECD was found in any corneal areas at any post-surgery follow-up visits. Tube-cornea angle was negatively correlated with the rate of corneal ECD loss at the tube insertion quadrant; r = −0.55 (P = 0.0013). In multivariable analyses, exfoliation glaucoma and narrower tube–cornea angle were significant prognostic factors for severe corneal ECD loss (P = 0.0068 and P = 0.046, respectively).

Conclusions

Anterior chamber Baerveldt glaucoma implantation causes corneal endothelial cell loss. Corneal endothelial cell loss starts at the tube insertion quadrant. Exfoliation glaucoma and narrower tube-corneal angle are associated with severe loss of corneal endothelial cells.

The protective effect of simvastatin against ultraviolet B-induced corneal endothelial cell death

Purpose:

Excessive ultraviolet B (UVB) exposure causing corneal endothelium injury, including apoptosis, is a serious condition. Therefore, drugs that can inhibit apoptosis in corneal endothelial cells represent an effective strategy. Simvastatin is widely used as a specific inhibitor of 3-hydroxy-3-methyl-glutaryl-CoA reductase, can reduce levels of low density lipoprotein (LDL) cholesterol, and exerts anti-inflammatory effects. However, the protective effect of simvastatin on corneal endothelial cells remains unclear. Therefore, the aim of this study was to elucidate whether UVB promotes the initiation of apoptosis in corneal endothelial cells and injury reversible by simvastatin treatment.

Methods:

We detected the cell viability, subG1 population, and caspase-3 activity.

Results:

Results showed that simvastatin alleviates UVB-induced cell death, cell apoptosis, and caspase-3 activity.

Conclusion:

Our findings indicated that simvastatin alleviated UVB-induced corneal endothelial cell apoptosis via caspase-3 activity.

Pseudoexfoliative glaucoma and molecular genetic characteristics of vitamin D metabolism

Purpose. To study the possible association of 25-hydroxyvitamin D level, and vitamin D receptor (VDR) gene polymorphisms (BsmI, ApaI, TaqI, FokI) with pseudoexfoliative glaucoma (PEG) clinical manifestations. Methods. We examined 160 subjects (72 males (45%), and 88 females (55%)) aged from 55 to 75 years, residents of St. Petersburg and Leningrad region. 122 patients with PEG were enrolled in the main study group, the control group comprised 38 subjects without PEG, primary open angle glaucoma (POUG) and pseudoexfoliation syndrome (PES). 25(OH)D serum levels were assessed by chemiluminescent immunoassay (CLIA) method. Detection of VDR gene allele polymorphisms (ApaI, BsmI, FokI, and TaqI) was carried out using polymerase chain reaction – restriction fragment length polymorphism (PCR-RFLP) technique. Results. Patients with PEG had lower 25(OH)D serum levels compared to patients in the control group (39.3 ± 1.2 and 52.7 ± 2.1 nMol/l, respectively, p < 0.01). The prevalence of vitamin D deficiency was found to be higher among PEG patients than among healthy subjects (86.4% and 59.5%, respectively, p < 0.01). The prevalence of b allele (p < 0.001) and bb genotype (p < 0.001) (BsmI polymorphism), as well as of f allele and ff genotype (p < 0.05) (FokI polymorphism) in PEG patients were higher compared to healthy subjects. We found that the Fallele carriers (FokI polymorphism) had greater corneal thickness than the ff genotype carriers (547.3 ± 4.1 μm and 502.1 ± 25.8 μm, respectively, p < 0.01). It was revealed, that bb genotype, Bb genotype (BsmI polymorphism), and ff genotype (FokI polymorphism) were associated with the increased risk of PEG (OR = 8.2, CI 95%: 3.4-19.9; OR = 3.9, CI 95%: 1.7-9.0; OR = 2.3, CI 95%: 1.2-4.5, respectively). Conclusions. Results of this study for the first time ever showed the association between BsmI and FokI VDR gene polymorphisms and pseudoexfoliative glaucoma.

Pseudoexfoliation signs in the anterior segment assessed by optical coherence tomography and Scheimpflug device

OBJECTIVE

To evaluate different anterior segment parameters in eyes with pseudoexfoliation (PSX), fellow eyes, and controls using optical coherence tomography and a Scheimpflug imaging system.

METHODS

Three groups were studied: 44 eyes of 44 patients with PSX, 30 clinically unaffected fellow eyes, and 148 eyes of 148 healthy controls. The anterior chamber depth and volume, corneal volume and thickness, pupil diameter and corneal densitometry were measured using a Scheimpflug imaging system (Pentacam, Oculus Inc.; Wetzlar, Germany). The angle width, the length and area of the trabecular meshwork, and the iris thickness were measured using an optical coherence tomography RTVue 100 device (Optovue, Fremont, CA, USA). The presence of PSX deposits was also assessed by OCT.

RESULTS

There were no differences in the anterior chamber volume or depth in the corneal volume or central thickness (P≥.228). The corneal densitometry was similar between PSX and fellow eyes; however it was greater than in the control group (P<.001). As regards the parameters measured by OCT, there were no differences in the angle width or in the trabecular meshwork size between the 3 groups; however, the iris was thinner in controls (P=.005). In all patients the PSX deposits were correctly visualised by OCT after the identification by biomicroscopy.

CONCLUSIONS

There were no differences in the anterior segment biometric measurements between patients with PSX and controls, although the corneal densitometry and iris thickness were greater in the PSX and fellow eyes groups.

Central corneal thickness and corneal volume changes in eyes with and without pseudoexfoliation after uneventful phacoemulsification

AIM

To investigate the effects of uneventful phacoemulsification on central corneal thickness (CCT) and corneal volume (CV) in pseudoexfoliative eyes during a 3 months postoperative period and compare these changes to eyes without pseudoexfoliation (PEX) syndrome. Another purpose of this study was to compare the CCT measurements done by ultrasound pachymetry (UP) with those done by the Oculus Pentacam.

MATERIAL AND METHOD

A total of 42 eyes of 42 consecutive patients with cataracts and PEX syndrome that underwent uneventful phacoemulsification were enrolled in this prospective study. A control group of 42 eyes of 42 patients with cataracts/without PEX was employed for comparison. CV and CCT measurements were obtained preoperatively and at 1 and 3 months postoperatively with the Pentacam. CCT values were also measured with UP. T test and Wilcoxon sign test were used to compare the variables.

RESULTS

The mean age of the patients was 72.1 ± 8.3 and 66.6 ± 9.6 years in PEX and non-PEX group, respectively. In both groups, there were no significant differences between preoperative and postoperative CV (Fig. 1), CCT by the Pentacam (Fig. 2) and CCT by UP (Fig. 3) values (p > 0.05). CCT measurements obtained by two devices were also similar, and there were no statistically significant differences (p > 0.05). Changes in CV and CCT remained stabile at 3 months postoperatively.

CONCLUSION

Eyes with and without PEX syndrome exhibit similar corneal features before and after phacoemulsification. A surgery in early stages of cataracts in PEX syndrome, not only provides a non-complicated surgery, but also leads to a less damaged cornea similar to eyes without PEX.

Ocular Pseudoexfoliation Syndrome Linkage to Cardiovascular Disease

PURPOSE OF REVIEW

Pseudoexfoliation syndrome (PEX) is a common cause of open-angle glaucoma that is characterized by stress-induced elastic microfibrillopathy related to an accumulation of matrix metalloproteinases. The accumulation of matrix metalloproteinases increases deposition of protein substance within ocular structures and other organs including the heart. Many studies have associated the presence of cardiovascular disease with pseudoexfoliation syndrome, but much debate exists between studies in terms of significant relationships. The following meta-analysis aims to relate pseudoexfoliation syndrome with certain cardiovascular events and disorders. A thorough literature review was performed to acquire information concerning PEX patients with certain cardiovascular disorders. Diseases considered included myocardial infarction, ischemic heart disease, angina, congestive heart failure, cardiomyopathy, aortic aneurysm, hypertension, and homocystinuria. Patients without evidence of pseudoexfoliation disease were the controls of our study. Multiple forest plots were created to compile and analyze collected data for statistical comparison.

RECENT FINDINGS

From a literature review, 18 studies were selected for our analysis. Cardiovascular disorders that had a statistically significant association (within a 95 % confidence interval) with PEX included ischemic heart disease, aortic aneurysms, and homocystinuria. The association between ischemic heart disease and PEX was statistically significant (p = 0.045). Myocardial infarction, chronic ischemic heart disease, angina, and hypertension did not show a correlation of relationship with the presence of pseudoexfoliation. Patients with PEX are prone to present with ischemic heart disease in addition to abdominal aortic aneurysms and homocystinuria. Patients that present with PEX should be screened for these detrimental cardiovascular disorders.

Measurements of Corneal Thickness in Eyes with Pseudoexfoliation Syndrome: Comparative Study of Different Image Processing Protocols

Purpose

Comparative analysis of central and peripheral corneal thickness in PEX patients using three different imaging systems: Pentacam-Scheimpflug device, time-domain optical coherence tomography (OCT) Visante, and swept-source OCT Casia.

Materials and Methods

128 eyes of 80 patients with diagnosed PEX were examined and compared with 112 normal, non-PEX eyes of 72 cataract patients. The study parameters included 5 measured zones: central and 4 peripheral (superior, inferior, nasal, and temporal).

Results

The mean CCT in eyes with PEX syndrome measured with all three instruments was thicker than that in normal eyes. Corneal thickness measurements in the PEX group were statistically significantly different between Pentacam and OCT Casia: central corneal thickness (p = 0.04), inferior corneal zone (p = 0.01), and nasal and temporal corneal zones (p < 0.01). Between Pentacam and OCT Visante inferior, nasal and temporal corneal zones were statistically significantly different (p < 0.01). Between OCT Casia and OCT Visante, there were no statistically significant differences in measured parameters values.

Conclusion

The central corneal thickness in eyes with PEX syndrome measured with three different independent methods is higher than that in the non-PEX group, and despite variable peripheral corneal thickness, this one parameter is still crucial in intraocular pressure measurements.

Prevalence of pseudoexfoliation syndrome and its association with ocular and systemic diseases in Eskisehir, Turkey

AIM

To investigate the prevalence of pseudoexfoliation syndrome (PEX) and its associations with ocular and systemic diseases in a population sample aged over 40y.

METHODS

A total of 2356 subjects were randomly chosen for the sample population based on the database of the Turkish Statistical Agency in Eskisehir. Of the invited 2356 subjects, 2017 subjects participated, out of which 2009 were eligible for the study. Systemic diseases, drug use, smoking and body mass index were assessed using questionnaires. Measurements of central corneal thickness (CCT), anterior chamber depth (ACD) and intraocular pressure (IOP) were performed during June to December, 2015. After pupillary dilation, the anterior segment and lenses were evaluated using a slit lamp.

RESULTS

Prevalence of PEX in this sample was 5.0% (n=100). Of patients with PEX, 26% also had glaucoma. Incidence of cataracts, and using drugs for hypertension, cardiac and psychiatric conditions was higher in patients with PEX compared to normal cases (P<0.05). Hearing loss was more common in PEX cases (34.0% vs 5.4%; P<0.001). The mean CCT, ACD and IOP were not significantly different between PEX and non-PEX cases.

CONCLUSION

This study is the first population-based, randomized trial in Turkey. Prevalence of PEX in patients over 40 years old was found to be 5.0%. Besides glaucoma and cataract, hypertension, hearing loss, using drugs for cardiac and psychiatric diseases were associated with PEX.

Corneal Alterations Associated with Pseudoexfoliation Syndrome and Glaucoma: A Literature Review

A systematic literature review was performed evaluating articles examining the effects of pseudoexfoliation syndrome (PEX) and glaucoma (PEXG) on the cornea with a focus on the corneal endothelium. We searched for articles relevant to pseudoexfoliation syndrome, pseudoexfoliation glaucoma and corneal endothelial cell counts using Pubmed, Google Scholar Database, Web of Science and Cochrane Library databases published prior to September of 2016. We then screened the references of these retrieved papers and performed a Web of Science cited reference search. Corneal characteristics analyzed included central corneal thickness (CCT), corneal nerve density, endothelial cell density (ECD), polymegathism, and pleomorphism. These parameters were compared in the following populations: control, PEX, PEXG, and primary open angle glaucoma (POAG). Over 30 observational studies were reviewed. Most studies showed a statistically significant lower ECD in PEX and PEXG populations compared to controls. Overall, PEX eyes had a non-statistically significant trend of lower ECDs compared to PEXG eyes. No consistent trends were found when analyzing differences in CCT amongst control, PEX and PEXG groups. For the few studies that looked at corneal nerve characteristics, the control groups were found to have statistically significantly greater nerve densities than PEX eyes, which had significantly greater densities than PEXG eyes. ECD and corneal nerve densities may be potential metrics for risk-stratifying patients with PEX and PEXG. Our literature review provided further evidence of the significant negative influence PEX has on the cornea, worsening as patients convert to PEXG.