Ultrastructural effects of silicone oil on the clear crystalline lens of the human eye

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.

Study on the efficacy and safety of foldable capsular vitreous body in the severe retinal detachment eyes

BACKGROUND

This study was to evaluate the efficacy and safety of the implantation of foldable capsular vitreous body (FCVB) in severe retinal detachment eyes.

METHODS

A retrospective study in retinal detachment eyes was performed at Shandong Provincial Hospital Affiliated to Shandong First Medical University. A standard three-port pars plana vitrectomy was performed, and the FCVB was triple folded and implanted into the vitreous cavity. The silicone oil (SO) was then injected into the capsule of the FCVB to support the retina and eye. During the follow-up period, The treated eyes were examined by ophthalmoscopy, fundus photography, and tonometry. B-scan ultrasonography, optical coherence tomography (OCT), and computed tomography (CT), were also performed.

RESULTS

From May 2020 to November 2021, 31 cases with severe retinal detachment were enrolled in the study. The postoperative follow-up time gradient ranged from 1 to 72 weeks, At various observation time points during the 72 weeks after surgery, The postoperative IOP was maintained at around 10 mmhg at various time points, with a slight decrease compared to the preoperative IOP (14.2 ± 4.6 mmHg n = 18), and was statistically significant. 9 of 31 patients had clear refractive media, both fundus and OCT showed retinal reattachment, OCT showed the 200 μm thick FCVB capsule support retina. The remaining 22 patients with unclear refractive media, B-scan showed arcuate hyperechoes in front of the retina. There was also no significant difference in visual acuity compared to preoperative. The FCVB was well positioned in the vitreous cavity, and no serious complications such as endophthalmitis, glaucoma, silicone oil emulsification, product exposure, or sympathetic uveitis were found.

CONCLUSIONS

FCVB has retinal support with certain ability to maintain IOP and eye morphology and avoid eye removal in patients with severe retinal detachment during the 72-week observation period.

An objective evaluation of lens transparency after vitrectomy surgery with different intravitreal tamponades

PURPOSE

To evaluate and compare the effects of different intraocular tamponade agents on lens density after vitrectomy.

METHODS

The participating patients were divided into four groups according to the tamponade agent used: a sulfur hexafluoride (SF₆) group, a perfluoropropane (C₃F₈) group, a silicone oil group, and a no tamponade group. Lens density measurements were performed preoperatively and two weeks, one month, and three months postoperatively using a Pentacam HR device with a Scheimpflug camera. The postoperative values were compared with the preoperative baseline values, also the values were compared between the four groups.

RESULTS

The study included 82 eyes (82 patients). In the SF₆ group, lens density significantly increased in all zones two weeks and one and three months postoperatively (all P < .05). In the C₃F₈ group, lens density significantly increased in all zones three months postoperatively (all P < .01). In the silicone oil group, the zone 1, zone 2, and average lens density (ALD) value significantly increased one and three months postoperatively (all P < .05). In the no tamponade group, the zone 1, zone 2, and ALD values significantly increased three months postoperatively (all P < .05). There were no significant differences between the four groups in any zone either preoperatively or postoperatively (all P > .05).

CONCLUSIONS

Although increases in lens density were observed earlier in the tamponade groups than in the no tamponade group, between the groups over the follow-up period were no differences. We need the development of new surgical methods and materials to prevent post-vitrectomy lens damage in the future.

"IRIS SHELF" TECHNIQUE FOR MANAGEMENT OF POSTERIOR SEGMENT INTRAOCULAR FOREIGN BODIES

PURPOSE

To describe "iris shelf" technique for removal of posterior segment intraocular foreign bodies (IOFBs) through a corneal incision combined with phacovitrectomy and to report its outcomes.

METHODS

Medical records of patients with posterior segment metallic IOFBs who had combined phacovitrectomy were collected and analyzed. In all patients, the IOFB was placed on the iris surface after forming the anterior chamber with viscoelastic to be extracted through a corneal phacoemulsification incision.

RESULTS

Thirty-three eyes of 33 male patients with a mean age of 31.6 ± 8.3 years were included in the study. The mechanism of injury was hammering in 24 eyes (72.7%) and gunshot in 9 eyes (27.3%). The mean interval between injury and IOFB removal was 14.76 ± 6 days. The mean IOFB volume was 8.5 ± 5.5 mm3, and its longest dimension was 3.45 mm (range, 1-8 mm). The mean preoperative corrected distance visual acuity changed from 20/1,500 (1.79 logarithm of the minimum angle of resolution) to 20/94 (0.67 logarithm of the minimum angle of resolution), postoperatively (P < 0.001). Postoperative complications included retinal detachment (two eyes), proliferative vitreoretinopathy (one eye), epiretinal membrane (one eye), and posterior synechiae (three eyes).

CONCLUSION

The "iris shelf" technique with phacovitrectomy is a safe and reproducible approach for posterior segment IOFB extraction through a corneal incision with favorable visual and anatomical outcomes.

Cataract Following Pars Plana Vitrectomy: A Review

Introduction: The indications for pars plana vitrectomy (PPV) have increased over the years. The vitreous is no longer considered an inert ocular structure and it is well known that its removal has anatomical and physiological consequences. The vitreous is no longer considered an inert ocular structure. The vitreous plays a key role as an intraocular physiologic oxygen regulator. In order to maintain its transparency, the crystalline lens needs protection from an excessive oxygen exposure. PPV leads to progression of nuclear sclerosis in most eyes.Methods: A systematic review of the literature was conducted using Embase and Medline databases. Articles studying the physiology, pathogenesis and surgical treatment of cataract after PPV were included in this review.Results: The pathogenesis of cataract formation after PPV remains unclear. Predisposing factors include advanced patient age, preexisting nuclear sclerosis, light toxicity, intraoperative oxidation of lens proteins, use of silicone oil or intravitreal gas, mechanical trauma and the duration of exposure to an irrigating solution.Conclusion: Cataract surgery in vitrectomized eyes presents with more technical difficulties, is more challenging and often has a higher risk of intraoperative and postoperative complications than in non vitrectomized eyes. There is no standardized technique or management in these cases; therefore, it requires more precautions during surgery.

Pathological Changes of the Anterior Lens Capsule

The anterior lens capsule (ALC), as the thickest basement membrane in the body, is an acellular, soft, smooth, transparent membrane secreted by lens epithelial cells. The ALC has its unique biomechanical properties to serve as a barrier and separate the lens from infectious viruses and bacteria together with the posterior capsule and pericapsular membrane. However, the biomechanical and ultrastructural properties of the ALC can be changed under certain conditions. Here, we provide a brief review of the pathological changes of the ALC in several eye disorders, including cataract, aniridia, climatic droplet keratopathy, exfoliation syndrome, true exfoliation syndrome, Alport syndrome, and silicone oil tamponade.