[Spontaneous rupture of the anterior lens capsule in Alport syndrome (case study)]. / Samoproizvol'noe vskrytie perednei kapsuly khrustalika pri sindrome Al'porta (klinicheskoe nablyudenie).

Alport syndrome is a hereditary disease characterized by glomerulopathy, manifested by hematuria and/or proteinuria, progressive decline in renal function, often combined with hearing and vision pathology. This article presents a clinical case of spontaneous opening of the anterior lens capsule in a patient with Alport syndrome, accompanied by uveitis and ophthalmic hypertension, and describes the features of the surgical aid and the postoperative period.

Measurement of tear resistance after manual capsulorhexis and femtosecond laser-assisted capsulotomy of crystalline lenses.

BACKGROUND: In this study, the tear resistance of porcine lens capsules after continuous curvilinear capsulorhexis (CCC) and femtosecond (fs)-laser-assisted capsulotomy for cataract surgery (FLC) with different laser parameters is measured with a custom-made testing setup. METHODS: Forty-five fresh porcine lenses were randomly chosen for CCC (n = 15) or FLC 1 (n = 15) and FLC 2 (n = 15). The FLC 1-group was treated with smaller spot distances than the FLC 2-group. The force necessary to break the opening of the anterior capsule and the maximum displacement were measured. RESULTS: The mean tear resistance of the CCC-group (150 ± 70 mN) was higher than that of the FLC 1-group (60 ± 20 mN) and the FLC 2-group (30 ± 20 mN). CONCLUSION: It could be shown that CCC leads to a significantly higher tear resistance of the opening than FLC in porcine lenses. The femtosecond laser group demonstrated that smaller spot distances lead to a higher tear resistance.

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.

Long noncoding RNA glutathione peroxidase 3-antisense inhibits lens epithelial cell apoptosis by upregulating glutathione peroxidase 3 expression in age-related cataract.

Purpose: Age-related cataract (ARC) is the leading cause of visual impairment and blindness worldwide. The apoptosis of lens epithelial cells (LECs) induced by oxidative damage is a major contributing factor to ARC. Long noncoding RNAs (lncRNAs) play important roles in various biologic processes. We aimed to explore the role of glutathione peroxidase 3 (GPX3)-antisense (AS) in ARCs. Methods: We extracted total RNAs from transparent and age-matched cataractous human lenses and detected lncRNA expression profiles using high-throughput RNA sequencing. The expression of GPX3-AS and GPX3 was detected by quantitative real-time PCR (qRT-PCR). Apoptotic proteins were detected by western blot and immunofluorescence. We treated SRA01/04 cells with H2O2 to mimic oxidative stress and induce cell apoptosis, which was analyzed by flow cytometry and TdT-mediated dUTP Nick-End Labeling (TUNEL) assay. The cell counting kit-8 (CCK-8) assay was used to detect the viability of SRA01/04 cells. The location of GPX3-AS was determined by fluorescence in situ hybridization (FISH) and cell nuclear and cytoplasmic RNA separation. Results: The lncRNA GPX3-AS, which is located in the nuclei of LECs, was downregulated in cataractous human lenses compared with control lenses, and proapoptotic proteins were expressed at high levels in the anterior lens capsules of ARC tissues. An in vitro study suggested that GPX3-AS inhibited H2O2-induced SRA01/04 cell apoptosis. As GPX3-AS is transcribed from the AS strand of the GPX3 gene locus, we further revealed its regulatory role in GPX3 expression. GPX3-AS was positively correlated with GPX3 expression. In addition, GPX3-AS inhibited H2O2-induced SRA01/04 cell apoptosis by upregulating GPX3 expression. Conclusions: In summary, our study revealed that GPX3-AS downregulated the apoptosis of LECs via promoting GPX3 expression, implying a novel therapeutic target for ARCs.

Advances in capsulorhexis.

PURPOSE OF REVIEW: Continuous curvilinear manual capsulorhexis is currently the standard of cataract surgery. In the past several years, new technologies have been developed to improve the consistency and safety of capsulorhexis creation. This article reviews the most recent technologies in capsulotomy formation and their advantages and disadvantages. RECENT FINDINGS: Guidance devices, femtosecond laser capsulotomy and precision pulse capsulotomy improve the centration, circularity and precision of anterior capsulorhexis and capsulotomy. These developments show particular promise for complex cataract surgeries, though clinical data on the refractive outcomes and complication rates of these technologies are currently limited and warrant additional investigation. SUMMARY: New technological advances in capsulorhexis help surgeons achieve a more ideal capsulotomy geometry. Whether this translates into more predictable refractive outcomes and safer surgeries remains an area of future study.

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.

Relationship between SIRT1 gene expression level and disease in age-related cataract cases

Background/aim: Age-related cataract is the most important visual impairment all over the world. Epigenetic modifications, especially overexpression of histone deacetylases, have become the focus of interest for cataract development in recent years. Sirtuin 1 (SIRT1), a class II histone deacetylase and a member of the sirtuin family, is one of the best-characterized histone deacetylases and has a pivotal role in age-related diseases. However, the association of SIRT1 with age-related cataracts has not yet been fully elucidated. Therefore, we aimed to determine the expression of SIRT1 in age-related cataract patients. Materials and methods: Expressions of SIRT1 were evaluated by quantitative polymerase chain reaction (qPCR) in patients and healthy controls. RNA samples were collected from the anterior capsule and peripheral blood samples of age-related cataract patients. Human lens epithelial cell line B3 and peripheral blood samples of healthy subjects were used as controls. Results: We determined that the expression of SIRT1 in blood and anterior capsule samples increased significantly compared to the control group (P < 0.05). Conclusion: The expression level of SIRT1 plays a vital role in the development of age-related cataract and it can be used as a biomarker. Thus, SIRT1 inhibitors can be used in the treatment of age-related cataract disease.

[Biomechanical properties of the anterior lens capsule after manual and femtolaser capsulotomy]. / Biomekhanicheskie pokazateli perednei kapsuly khrustalika posle manual'noi i femtolazernoi kapsulotomii.

PURPOSE: To comparatively evaluate the mechanical stability of the edge of central fragment of anterior lens capsule after manual and femtolaser capsulotomy. MATERIAL AND METHODS: The mechanical tests were performed on the central fragments of the anterior lens capsules obtained intraoperatively after manual and femtolaser capsulotomy (15 and 13 samples, respectively). The conditions of the developed method of mechanical testing are as close to in vivo as possible. The method allows evaluation of the mechanical response mainly from the edge of the sample, reception of the averaged response from the four edges of the capsule, and almost eliminates the effect of additional edge notches in samples obtained by manual capsulotomy. RESULTS: After manual capsulotomy, the maximum force and elongation of the anterior capsule sample at maximum tensile strength were significantly higher than similar characteristics of the samples after femtolaser capsulotomy. CONCLUSION: The obtained results correspond with the morphological studies of capsule edge structure after manual and femtolaser capsulotomy. The edge of the anterior capsule after femtolaser capsulotomy has form, in rough approximation, close to one of a postage stamp perforation, which is the consequence of micro-irregularities (microfractures) in the areas irradiated by pulsed laser, and wider area of deepithelization compared to the manual technique.

Ultrastructural Integrity of Human Capsulotomies Created by a Thermal Device.

PURPOSE: To investigate the ultrastructural features of anterior capsulotomy performed with a thermal device, the precision pulse capsulotomy (PPC). DESIGN: Prospective, multicenter case series. PARTICIPANTS: Consecutive patients undergoing capsulotomy with the PPC device. METHODS: Prospective study of patients undergoing capsulotomy with the PPC by 2 surgeons, followed up by routine phacoemulsification cataract surgery, was undertaken. All capsulotomy specimens were collected for scanning electron microscopy (SEM). Observations were made regarding uniformity of the capsular edge and the presence of irregularities that may compromise integrity. Comparisons were made with manual continuous curvilinear capsulorrhexis. MAIN OUTCOME MEASURES: Ultrastructural features of PPC and presence of irregularities. RESULTS: Frayed appearance of the anterior capsule edge was noted in postoperative visits under slit-lamp examination. Scanning electron microscopy sampling showed a generally uniform rolled capsular edge, but interspersed with areas of irregularity with frayed appearance at the capsule margin. CONCLUSIONS: The PPC device is capable of creating reproducible, central, and precise circular capsulotomy. The ultrastructural features in ex vivo human capsulotomy specimens generally show eversion of the capsulotomy edge, but in some cases, this was accompanied by areas of irregular capsule margin with frayed edges, likely caused by dissipated thermal energy. The postoperative appearance and SEM features warrant further assessment of the PPC integrity and clinical correlation.

Anterior lens capsule strains during simulated accommodation in porcine eyes.

Experimental protocols have been developed to measure the spatial variation of the mechanical strains induced in the lens capsule during ex vivo lens stretching. The paper describes the application of these protocols to porcine lenses. The deformations and mechanical strains developed in the anterior capsule during each experiment were determined using full field digital image correlation techniques, by means of a speckle pattern applied to the lens surface. Several speckling techniques and illumination methods were assessed before a suitable combination was found. Additional data on the cross section shape of the anterior lens surface were obtained by Scheimpflug photography, to provide a means of correcting for lens curvature effects in the determination of the strains developed in the plane of the capsule. The capsule strains in porcine lenses exhibit non-linear behaviour, and hysteresis during loading and unloading. Peripheral regions experience higher magnitude strains than regions near the lens pole. The paper demonstrates the successful application of a procedure to make direct measurements of capsule strains simultaneously with ex vivo radial lens stretching. This experimental technique is applicable to future investigations on the mechanical characteristics of human lenses.

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.

[Complex morphological assessment of anterior capsule of the lens in patients with capsular contraction syndrome (a clinical case study)]. / Kompleksnaia morfologicheskaia otsenka perednei kapsuly khrustalika pri kapsuliarnom kontraktsionnom sindrome (klinicheskoe nabliudenie).

The anterior capsular contraction syndrome (ACCS) in pseudophakic patients is known to be accompanied by postoperative opacity of anterior lens capsule (ALC) and partial or full closure of anterior capsulotomy opening. PURPOSE: To perform complex morphological assessment of ALC in patients with ACCS. MATERIAL AND METHODS: The study involved complex analysis of ALC that was removed due to ACCS in the pseudophakic eye in the setting of diabetes mellitus and past vitreoretinal surgery. The following examination methods were used: light-optical microscopy of ALC samples in the form of polychrome-colored semifine sections using optical microscope Leica DM-2500 (Germany), scanning microscopy of ALC surface with EVO LS10 (Carl Zeiss, Germany) microscope, analysis of chemical element composition and its variation of the ALC sample with energy-dispersive spectrometer Oxford X-Max50 (Oxford, UK). RESULTS: Light-optical microscopy showed altered state and plication of ALC induced by proliferation from inner surface of the fibrocellular tissue, which gradually thickens (up to 360 µm) towards center and causes reduction of anterior capsulotomy opening. Scanning electron microscopy revealed presence of tissue with uneven micro-relief and a porous three-dimensional structure uncharacteristic for capsule on the surface of ALC. Thickness of the fibrous deposition significantly exceeded the thickness of ALC. Evaluation of elemental composition of the fibrocellular tissue showed elevated concentration of sulfur and phosphorus, which indicates high activity of the regenerative process. In the observed case, the regenerative process was of substitute nature because an attempt to restore the lens was accompanied by formation of connective tissue structurally different from original. CONCLUSION: Complex assessment of an isolated ALC sample allowed revelation of the chain of pathological processes accompanying the development of ACCS.

Intraoperative management of anterior capsular tear.

PURPOSE OF REVIEW: The article reviews the current literature on intraoperative techniques to properly manage anterior capsular tears during cataract surgery. RECENT FINDINGS: Femtosecond laser-assisted cataract surgery creates a more consistent capsulorhexis than traditional capsulotomies, but can also present with new challenges. Irregularities, like microadhesions and tags, can lead to anterior tears if not properly treated. New technology, like the Zepto (Mynosys, Fremont, CA, USA) pulse precision capsulotomy, may produce a smoother edge and reduce the incidence of capsular tears. However, there are novel rescue techniques in the case that a tear-out does occur. SUMMARY: Anterior capsular tears can occur at any stage of cataract surgery. The proper management of these tears will prevent them from extending into the posterior capsule and compromising the structural integrity of the capsular bag. This is essential for endocapsular placement of artificial lenses and for optimal visual outcomes for the patient.

Anterior lens capsule and epithelium thickness measurements using spectral-domain optical coherence tomography.

BACKGROUND: To investigate the anterior lens capsule and epithelium thickness (defined as anterior lens capsular complex: ALCC) in normal Chinese subjects using spectral-domian optical coherence tomography (SD-OCT) and examine the factors that may influence the ALCC, such as age, gender, pupil diameter (PD) and signal strength index (SSI). METHODS: A prospective observational case series. One-hundred-thirty-four normal subjects (134 eyes) were included. The ALCCs were determined manually via SD-OCT. Using the pupil center as a reference position, the central ALCC (CALCC), nasal 1-mm ALCC (NALCC), temporal 1-mm ALCC (TALCC) and PD were measured manually. RESULTS: The mean CALCC, NALCC and TALCC were 33 ± 6 µm, 36 ± 7 µm and 34 ± 6 µm, respectively. The NALCC was significantly thicker than the CALCC (P < .001) and TALCC (P < .001). Moreover, CALCC was significantly thinner than TALCC (P = 0.013). Age was positively correlated with the CALCC (r = 0.292, P < .001), NALCC (r = 0.400, P < .001) and TALCC (r = 0.521, P < .001). PD, gender and SSI were not significantly correlated with the three ALCC parameters. CONCLUSIONS: The SD-OCT can be used to demonstrate the ALCC thickness, and age is positively correlated with the ALCC in the central, nasal and temporal sides.

Femtosecond laser-assisted cataract surgery in patients with phakic intraocular lenses and low endothelial cell counts: a case report.

BACKGROUND: Phakic intraocular lens (PIOL) implantation has been used to correct myopia and myopic astigmatism, although corneal decompensation can occur after implantation. Femtosecond laser-assisted cataract surgery (FLACS) has gained in popularity due to its lower postoperative astigmatism and endothelial loss. Herein, we report the use of FLACS in patients who previously received PIOL implantation and have a low corneal endothelial cell count. CASE PRESENTATION: Two patients with a previous iris-claw PIOL implantation were enrolled. The preoperative corrected distance visual acuity (CDVA) and diopter sphere (DS) were 20/32 and -0.25 D in patient 1 and 20/32 and -3.00 D in patient 2. Specular microscope examination revealed an endothelial cell density (ECD) of 1532/mm2 in patient 1 and 1620/mm2 in patient 2. Capsulotomy was performed smoothly using a femtosecond laser. Postoperative CDVA improved in both eyes, with a difference of DS less than 1 D from the preoperative estimation. Specular microscope examination revealed a decreased endothelial cell density (ECD) in patient 2, but no signs of corneal decompensation were detected. CONCLUSIONS: The influence of using PIOL on capsulotomies performed via FLACS, in combination with preoperative refraction calculation, is minimal. A mild decrease in ECD may occur, but there is a low probability of severe corneal decompensation, even in patients with a low endothelial cell count.

[Capsule contraction syndrome in pseudophakia]. / Kontraktsionnyi kapsuliarnyi sindrom pri artifakii.

This is a review of the literature on capsule contraction syndrome (CCS) in pseudophakic patients that involves severe fibrosis along the margin of the anterior capsule's opening and progressive contraction of the capsular bag. Possible causes of CCS and principles of its prevention and treatment have been analyzed.

[Morphological and clinical aspects of anterior capsulotomy in femtosecond laser-assisted cataract surgery]. / Morfologicheskie i klinicheskie aspekty perednei kapsulotomii v fakokhirurgii c primeneniem femtosekundnogo lazera.

The review covers morphological and clinical aspects of femtosecond laser-assisted anterior capsulotomy in cataract surgery. Literature data suggests that femtosecond laser-assisted capsulotomy is more accurate in size, shape, and centration than manual. Femtosecond laser-assisted anterior capsulotomy improves the accuracy of IOL positioning within the capsular bag.

[n.s.i.n.i.V. Biomechanical aspects of anterior capsulotomy in cataract surgery]. / Biomekhanicheskie aspekty perednei kapsulotomii v fakokhirurgii.

This paper reviews studies on biomechanical properties of the anterior lens capsule. Early experiments in this field were more fundamental. Later studies were aimed mainly at assessing the mechanical stability of the capsule edge after manual or femtosecond laser capsulorhexis (capsulotomy) - an important step in modern minimally invasive phaco surgery. For biomechanical tests, ex vivo samples of human and animal anterior capsules were used. The results of the studies presented here are quite heterogeneous, which suggests the necessity of gaining further insight into the issue.

[Combined YAG-laser capsulotomy in pseudophakic patients with anterior capsular contraction syndrome]. / Tekhnologiia kombinirovannoi lazernoi kapsulotomii pri perednekapsuliarnom kontraktsionnom sindrome v artifakichnykh glazakh.

Progressive metaplastic fibrosis of the anterior capsulorhexis opening is a frequent complication of the postoperative period. There is a widely practiced method of anterior capsular contraction syndrome (ACCS) correction through radial anterior laser capsulotomy. Despite many advantages, it can be complicated by unpredictable anterior capsule tearing and intraocular lens (IOL) dislocation into the vitreous Body, which justifies the search for new technical solutions. AIM: to develop a safe technique of combined laser anterior capsulotomy (LAC) in patients with ACCS. MATERIAL AND METHODS: The study included 19 patients (20 eyes) with ACCS. The suggested LAC technique involved two differently directed YAG-laser cuts that could be regarded as a combination of radial anterior capsulotomy and anterior peripheral linear capsulotomy. With the cuts located perpendicularly to each other, the distal end of each radial cut was connected to the middle of each longitudinal cut. RESULTS: The suggested technique allows an increase in the anterior capsulorhexis diameter up to more than twice the pre-laser size. The difference between the average pre- and post-laser capsulorhexis diameters was statistically significant (р<0.0001). Neither case developed an unpredictable anterior capsule tear. CONCLUSION: The safety of the new technique is ensured by preliminary longitudinal cuts that create a barrier against unpredictable radial tears in the capsular bag during radial capsulotomy.

Comparison of Manual, Femtosecond Laser, and Precision Pulse Capsulotomy Edge Tear Strength in Paired Human Cadaver Eyes.

PURPOSE: To compare the anterior lens capsulotomy edge tear strength created by manual continuous curvilinear capsulorhexis (CCC), femtosecond laser capsulotomy (FSLC), and a new automated precision pulse capsulotomy (PPC) device. DESIGN: A 3-arm study in paired human cadaver eyes. PARTICIPANTS: A total of 44 eye specimens from 22 donors in the United States. METHODS: Capsulotomy was performed in all eye specimens using manual CCC, a femtosecond laser (LenSx, Alcon, Fort Worth, TX), or an automated PPC device (Zepto, Mynosys Inc., Fremont, CA). The first study arm consisted of 8 pairs of eyes in which 1 eye received PPC and the fellow eye received FSLC. The second study arm consisted of 8 pairs of eyes, with 1 eye receiving PPC and the fellow eye receiving manual CCC. The third study arm consisted of 6 pairs of eyes, with 1 eye receiving a manual CCC and the fellow eye receiving FSLC. After phacoemulsification, 2 capsulotomy edge retractors attached to force transducers were used to stretch the capsulotomy edge of each eye and to measure the resisting force until the capsulotomy edge was torn. MAIN OUTCOME MEASURES: Capsulotomy edge tear strength in millinewtons. RESULTS: The PPC edge tear strength was greater than that of FSLC for all 8 pairs of eyes by an average factor of 3.1-fold (PPC mean 73.3±24.9 mN vs. femtosecond laser mean 26.1±6.8 mN; P = 0.012, Wilcoxon matched-pairs, signed-ranks test). The PPC tear strength was greater than that of manual CCC for all 8 pairs of eyes by an average factor of 4.1-fold (PPC mean 95±35.2 mN vs. manual CCC mean 29.1±23.1 mN; P = 0.012, Wilcoxon matched-pairs signed-ranks test). There was no significant difference in the tear strength of capsulotomies produced by manual CCC (mean 21.3±4.9 mN) and FSLC (mean 24.5±11.4 mN) (P = 0.75, Wilcoxon matched-pairs signed-ranks test). CONCLUSIONS: The strength of the PPC capsulotomy edge was significantly stronger than that produced by femtosecond laser or manual CCC.