A New Technique of Pars Plana Vitrectomy with Microinterventional Nucleus Disassembly to Reduce the Energy of Fragmatome Lensectomy for Posteriorly Dislocated Crystalline Lens Removal
Purpose is to review the pathogenic mechanism for ocular hypertension and glaucoma development after pars plana vitrectomy. Both acute and chronic causes are considered, and special attention is paid to the theories and clinical evidence on the risk of developing Open Angle Glaucoma (OAG) after Pars Plana Vitrectomy (PPV). Most existing scientific literature on the issue agree on the role of ascorbate as an oxygen scavenger within the vitreous chamber. Oxygen tension in the vitreous and anterior chamber is maximum inn proximity of the retinal surface and endothelium, respectively and steeply decreases toward the lens, on both sides, and trabecular meshwork. Vitreous removal and, to a lesser extent, liquefaction, greatly reduces oxygen tension gradient in vitreous chamber while cataract extraction has similar effects on anterior chamber oxygen gradients. Oxygen derivatives originated from the cornea and retina are actively reduced by the vitreous gel and/or the crystalline lens. Vitreous removal and cataract extraction reduce drastically this function. Most reported clinical series confirm this hypothesis although protocol difference and follow-up length greatly impact the reliability of results.
Purpose: To report the clinical course of ophthalmia nodosa with a retained lenticular seta misdiagnosed and treated as non-infectious posterior uveitis for 7 consecutive years. Methods: Meticulous clinical examination led to discovery of the caterpillar seta embedded in the crystalline lens and the intravitreal setae. Results: Lens-sparing pars plana vitrectomy and removal of free-floating vitreal seta resulted in complete resolution of vitritis and uveitis. Conclusion: Embedded seta within a clear lens may remain sequestered, and may be left untouched under close observation, precluding a clear lens extraction in such patients.
Pars plana vitrectomy (PPV) is currently used as an effective method in many posterior segment pathologies. Although the most common indication is retina and vitreous pathologies, PPV is also preferred in some cases associated with lens and glaucoma. In case the crystalline lens or artificial intraocular lens, which is a product of industrial development, falls into the vitreous, it is essential to remove it mostly with the PPV approach. In some types of secondary glaucoma, especially malignant glaucoma, successful results are obtained in terms of visual prognosis and complications with vitreoretinal surgery techniques.
Fluctuating anterior chamber depth and reverse pupillary block are the most common problems encountered during phacoemulsification following pars plana vitrectomy in cases of cataracts. The sudden deepening of the anterior chamber makes the surgical procedure more cumbersome and increases the risk of intraoperative complications. To solve this problem, we describe a method of balancing the pressure of the anterior and posterior chamber by using a syringe with a flushing needle to inject balanced salt solution into the posterior chamber via the gap between the iris and the anterior capsule of the lens. This technique is especially suitable for complicated cataracts following previous pars plana vitrectomy and high myopia-complicated cataracts. This technique yielded promising results in reducing the difficulties that occur during surgical procedures, reduced the risk of intraoperative complications and simplified the intraocular lens implantation.
Blunt ocular trauma is the one of the commonest cause of anterior dislocation of the crystalline lens. We present a case who presented with anterior dislocation of the crystalline lens, vitreous prolapse, and acute painful vision loss in left eye following blunt trauma. The patient was managed with antiglaucoma medications, automated anterior vitrectomy, and surgical extraction of dislocated lens with a delayed pars plana vitrectomy and transcleral fixation of crystalline lens.
We describe the case of a 65-year-old Indian male with a subretinal crystalline lens; an unusual complication of blunt trauma. The patient underwent a three port pars plana vitrectomy during which the subretinal location of the crystalline lens under the inferior giant retinal tear was confirmed. The lens was maneuvered into the vitreous cavity and appropriately managed.
AbstractWe describe a new technique for non-contact in vivo corneal and lenticular microscopy. It is based on fundus retro-reflection and back-illumination of the crystalline lens and cornea. To enhance phase-gradient contrast, we apply asymmetric illumination by illuminating one side of the fundus. The technique produces micron-scale lateral resolution across a 1-mm diagonal field of view. We show representative images of the epithelium, the subbasal nerve plexus, large stromal nerves, dendritic immune cells, endothelial nuclei, and the anterior crystalline lens, demonstrating the potential of this instrument for clinical applications.
A New Technique of Pars Plana Vitrectomy with Microinterventional Nucleus Disassembly to Reduce the Energy of Fragmatome Lensectomy for Posteriorly Dislocated Crystalline Lens Removal
