Detecting Apoptotic Human Lens Epithelial Cells With Transmission Electron Microscopy.

Introduction Cataract formation is a prevalent issue worldwide, and understanding the cellular processes involved is crucial to advancing treatment options. The scope of the study was to explore the presence of apoptotic cells in the lens epithelium of Greek patients with senile cataracts using transmission electron microscopy (TEM). Methods Twenty-one patients with senile cataracts were included in this cross-sectional study, and their anterior lens capsules were thoroughly examined. The presence of apoptosis was ultrastructurally investigated, and its association with age, gender, biomicroscopic type of cataract, the coexistence of exfoliation syndrome (XFS), diabetes mellitus, and glaucoma was statistically correlated. Results We detected apoptotic cells in nine of the 21 patients. Morphological features indicative of apoptosis in the nuclei included degradation, nuclear membrane irregularity, reduction of nuclear volume, condensation, and margination of chromatin. The cytoplasm either appeared denser or contained vacuoles. Budding with membrane blebbing and pinopode-like projections were frequently observed. Apoptotic cells appeared smaller, exhibiting loose connections with neighboring cells and the basement membrane (BM). Interestingly, apoptotic bodies were also detected. Conclusions None of the examined risk factors showed a connection to apoptosis, whereas neighboring lens epithelial cells (LECs) phagocytose apoptotic bodies, seemingly assumed the role of macrophages. Comparing apoptosis rates between populations with different sun exposure levels could help reveal the relationship between ultraviolet B radiation exposure, apoptosis, and cataract formation.

An Uncommon Aflibercept Side Effect: Full Thickness Macular Hole Formation After Intravitreal Injections in Patients With Pre-existing Vitreomacular Traction.

Aflibercept is an intravitreally injected anti-vascular endothelial growth factor, commonly used in patients with several retinal pathologies, including neovascular age-related macular degeneration. We report a case series of three patients under treatment with an aflibercept regime for neovascular age-related macular degeneration, who were referred to vitreoretinal service between 2015-2016. In all cases, pre-existing vitreomacular traction was detected with an optical coherence tomography scan. All of them developed full-thickness macular hole after aflibercept intravitreal injections. The combined cataract and macular hole surgery was successful, with improvement in visual acuity. We suggest that dynamic alterations of the size of the pigment epithelium detachment resulting from intravitreal injections might intensify the pre-existing pathological adhesion of the vitreous-retinal interface and subsequently cause the formation of a full-thickness macular hole. Therefore, all practitioners treating patients with aflibercept intravitreal injections and pre-existing vitreomacular traction should be aware of the possible macular hole formation.

Lens Epithelial Surface Disorders in Exfoliation Syndrome: A Scanning and Transmission Electron Microscopy Study.

BACKGROUND: Hydrodissection was recently reported to occur more easily in patients with exfoliation syndrome (XFS). Transmission electron microscopy (TEM) studies have already revealed alterations of the lens epithelial cells (LECs) and their apical membrane towards the lens fibers. OBJECTIVE: The aim of this work was to examine the three-dimensional appearance of the lens epithelium in patients with XFS. METHODS: Fourteen patients with senile cataract, 7 of whom had XFS, were included. Anterior lens capsules (aLCs) were obtained with continuous curvilinear capsulorrhexis (CCC) during phacoemulsification and were examined with scanning electron microscopy (SEM) and TEM. RESULTS: Exfoliation samples exhibited an overall more irregular apical surface of the lens epithelium compared to control aLCs. The height of LECs varied extensively. On the apical surface of LECs, amorphous, crystalline-like, or microgranular extracellular material and membranous, oval-shaped structures were documented with SEM. All findings were connected to corresponding observations with TEM and were not correlated to the type of cataract. CONCLUSIONS: In XFS patients, the lens epithelial surface exhibited a highly irregular margin, with extracellular material covering the apical membrane of LECs. We suggest that XFS probably causes both epithelial and lens fiber degeneration which, during CCC and mechanical extraction of the aLC from the lens cortex, result in diverse alterations.

Ease of Hydrodissection during Phacoemulsification: A Comparison between Patients with and Those without Exfoliation Syndrome.

BACKGROUND: Exfoliation syndrome (XFS), which is associated with increased surgical complications during phacoemulsification, has a relatively high incidence in Greece. Multiannual surgical experience in XFS patients has led to the clinical observation that hydrodissection occurs more easily in XFS patients. OBJECTIVE: To compare the ease of hydrodissection between cataract patients with and those without XFS. METHODS: One hundred and fifteen patients with senile cataract were included in the study. Forty-two of them had XFS. All patients underwent uneventful phacoemulsification by the same surgeon. For hydrodissection, three 1-mL insulin syringes were filled with 0.5 mL balanced salt solution (BSS). Sequentially, each one was quickly and continuously injected underneath the 3, 6, and 9 o'clock positions of the anterior lens capsule. If lens mobilization was achieved with this procedure, hydrodissection was characterized as "easy." RESULTS: The two groups were matched for age, gender, the biomicroscopic type of cataract, and the presence of diabetes mellitus. Glaucoma occurred more often among the XFS patients (p = 0.002). In 39 of the 42 exfoliation patients (92.8%), "easy" hydrodissection was recorded. In the control group, the corresponding number was 47 out of 73 (64.3%). The two groups differed significantly (p = 0.001). CONCLUSIONS: Hydrodissection was more easily performed on the XFS patients than on the controls. This finding could be related to the extensive ultrastructural subepithelial alterations of the anterior lens capsule in XFS, as recently described in electron microscopy studies. We suggest that less BSS can be used for hydrodissection in XFS patients during phacoemulsification.

The role of neuronal apoptosis in Valproic Acid brain-related teratogenesis: a histochemical and immunohistochemical study in BALB/c mice.

OBJECTIVES: The purpose of this study was to examine the teratogenic effects of Valproic Acid (VPA) and to investigate the role of apoptosis in neural tissue development. Although an apoptotic activity due to VPA has been reported, a direct connection of VPA-induced apoptosis with embryonic brain and∕or spine malformations and teratogenesis has not yet been established. MATERIALS AND METHODS: VPA was administered to BALB∕c mice, from the 7th to the 10th gestational days. Macroscopical congenital anomalies were registered under a stereomicroscope and were further histologically studied. Immunohistochemistry was performed with terminal deoxynucleotidyl transferase (TdT)-mediated deoxyuridine triphosphate (dUTP) nick-end labeling (TUNEL) staining. RESULTS: Birth defects were described and an increase of the apoptotic activity in the brain was immunohistochemically identified. CONCLUSIONS: Considering the increased and very intense TUNEL expression of the neural cells of treated animals' fetuses, it is suggested that VPA triggers a pathological increase of apoptosis resulting in an imbalance between cell proliferation and cell death, the final result of which is malformation.

Spontaneous Lens Rupture in Congenital Cataract, Presented as Lens Fragment Within the Anterior Chamber.

We report the case of a 60-year-old woman with a congenital anterior polar cataract who presented with a lens fragment within the anterior chamber of her left eye, without a medical history of surgery or trauma. Uneventful phacoemulsification with simultaneous removal of the lens fragment followed. Postoperatively, the patient's visual acuity improved from a perception of light to 20/100. Histological examination of the lens fragment revealed persistent fetal vasculature, as well as fibrous metaplasia and extensive collagenesis. To our knowledge, this is the first report of spontaneous rupture of both the anterior capsule and the lens.

Severe Abnormalities of Lens Epithelial Cells in Exfoliation Syndrome: A Transmission Electron Microscopy Study of Patients with Age-Related Cataract.

Background and objectives: The aim of this study was to examine via electron microscopy the lens epithelial cells in age-related cataracts and compare the findings between patients with and without exfoliation syndrome, in the Greek population. Materials and Methods: Twenty-one patients with age-related cataracts, older than 60 years, were included in the study. Eleven of them also suffered from exfoliation syndrome. Anterior lens capsules, obtained during phacoemulsification, were examined with a transmission electron microscope. Results: In all cases, ultrastructural features of diffuse intracellular and extracellular oedema were noticed to a varying degree and transparent vacuoles were detected. Often, there was more than one layer of cells, giving the impression that healthier cells tried to cover neighboring cells presenting extensive damage. Commonly, cells lost their regular shape and appeared with expanded nuclei carrying dense granules. Apoptotic cells were also detected. The epithelial cells frequently were completely destroyed or absent, exhibiting loose connections amongst them or with the basement membrane. In exfoliation syndrome (XFS) patients the alterations were more severe. Additionally, the lens epithelial cells (LECs) apical cell membrane appeared with varying distances from the basement membrane, due to different cell "heights", creating an irregular margin of the epithelium (p<0.05). Conclusion: Transmission electron microscope (TEM) examination revealed ultrastructural abnormalities in all patients' lens epithelia, more extended and more frequently observed in XFS group. In all cases, the lesions were comparable to those described in severe pathologies, all of which were excluded from the study. Environmental factors such as increased ultraviolet B (UVB) radiation exposure in Mediterranean countries, genetic factors, epigenetic factors, or all of them, could contribute to these alterations. Further epidemiological and molecular biology research is needed, so as to justify these results.

Exfoliation Fibrils within the Basement Membrane of Anterior Lens Capsule: A Transmission Electron Microscopy Study.

Purpose: The aim of the present study was to demonstrate novel findings recognized within the basement membrane of the anterior lens capsules (ALCs) in exfoliation syndrome, in a transmission electron microscopy (TEM) study. Materials and methods: Twenty-one patients with age-related cataract were included in the study. Eleven out of them suffered from exfoliation syndrome (XFS). Anterior lens capsules were obtained from patients during phacoemulsification, applying continuous curvilinear capsulorhexis and then were examined by transmission electron microscope. Results: Six out of 11 examined basement membranes with XFS had a granular appearance with dotted deposits of electron-dense material. Fibrils were clearly detected, longitudinally, within the basement membrane, usually located in the outer quarter of the basement membrane, towards the anterior chamber. Conclusion: New data about the exfoliation material and its location within the basement membrane of the anterior lens capsules of XFS patients are presented. These findings constitute new evidence for XFS's histopathogenesis and might help clarify the lenticular exfoliation material's (XFM) mechanisms of origin.

Transmission electron microscopy study of undescribed material at the anterior lens capsule in exfoliation syndrome.

PURPOSE: In the present study, we aimed to examine the anterior lens capsule using transmission electron microscopy (TEM) and compare the findings in patients with and without exfoliation syndrome (XFS). METHODS: Eighteen patients with senile cataract, including 10 with XFS, were included. Anterior capsule specimens were obtained from patients during phacoemulsification through continuous curvilinear capsulorrhexis, and were examined via TEM. RESULTS: In the XFS group, in addition to the typical fibrillar material above the basement membrane of the lens capsule, another unknown, microgranular, electron-dense, unbound material was observed beneath the lens epithelium. Larger formations appeared to detach from the surface of the epithelial cells, and oval or crescent-shaped structures of an electron-denser material were less commonly observed on the apical side of the epithelium. Membranous structures were occasionally attached to epithelial cells that often exhibited thicker or ruptured cell membranes on their apical-free side, along with deposits of electron-dense material. Degenerative lesions of various severities were observed at the epithelium in both groups. CONCLUSION: The anterior lens capsule epithelium in patients with XFS exhibits a highly irregular and rough margin on its free side, with unbound material over its membrane, which probably contributes to loose contact with the underlying lens and leads to different clinical behaviors in XFS eyes during cataract surgery.