【In Press】 Endoscopy-assisted vitrectomy in the anterior vitreous

Endoscopy-assisted ocular surgery is a relatively old technique that is increasingly being recognized for its application in cases of vitreoretinal disease. This technique is especially useful when both the vitreous and retina are difficult to access because of media opacity, a small pupil, or a microcornea. In this context, the anterior vitreous is often difficult to dissect because of its complex pathological changes. This article reviews the common anatomical features and pathologies that are observed in the anterior vitreous, as well as the applications and indications of endoscopy-assisted vitrectomy in the anterior vitreous.     

Surgically induced detachment of the anterior hyaloid membrane from the posterior lens capsule

Vitreous hemorrhage adhering to the posterior lens capsule prevents adequate visualization of the vitreous cavity and fundus during vitreous surgery and during the dissection of fibrovascular membranes. This type of hemorrhage is difficult to remove by aspiration or resection using a vitreous cutter. We have developed a new technique designed to detach surgically the anterior vitreous for the removal of hemorrhage in patients with proliferative diabetic retinopathy. In this hydrodissection technique, the anterior vitreous is detached from the posterior lens capsule by a forced injection of infusion fluid into the anterior chamber. This technique separates the vitreous hemorrhage adhering to the posterior lens capsule and allows its removal.     

Management of vitreous loss and dropped nucleus during cataract surgery

The intraoperative management of complication during cataract surgery of vitreous loss and dropped nucleus strongly influences the outcome, and a well-rehearsed plan for both staff and surgeons is needed. Preventative measures, early recognition, damage control, and resolution are discussed in this article. Maintenance of appropriate pressure relationships and tissue planes limits vitreous prolapse and the surgeon's primary goal is to avoid vitreous traction resulting in retinal tears and detachment. A pars plana approach to anterior vitrectomy with staining of the prolapsed vitreous is the most effective technique. Although residual lens material should be removed from the anterior and posterior chambers, once a fragment is lost to the posterior segment, the authors advocate referral for a standard three-port posterior vitrectomy with fragmenter as needed because the goal of the cataract surgeon is to offer the patient a clean, pseudophakic anterior segment and the best chance for an optimal visual recovery.     

Videoendoscope-guided fluorescein-assisted vitrectomy for phakic malignant glaucoma

Malignant glaucoma is a rare secondary glaucoma classically occurring after intraocular surgery in eyes with primary angle closure. Pars plana vitrectomy is reserved for the treatment of malignant glaucoma when medical and laser treatment fail. The primary aim of surgery is the removal of the anterior vitreous to reduce resistance to aqueous flow into the anterior chamber. In phakic eyes, conventional pars plana vitrectomy without lens extraction is frequently unsuccessful because of difficulty visualizing the normally transparent anterior vitreous, combined with the technical challenge of removing the anterior vitreous without damaging the crystalline lens. We describe a technique of intraocular, videoendoscope-guided, fluorescein-assisted pars plana vitrectomy that enables direct visualization and thorough removal of the anterior vitreous without the need for lens extraction in prepresbyopic patients without cataract.     

Sutureless single-port transconjunctival pars plana limited vitrectomy combined with phacoemulsification for management of phacomorphic glaucoma

We describe a technique that uses a small-gauge, single-port, sutureless transconjunctival limited pars plana vitrectomy to facilitate phacoemulsification in eyes with a shallow anterior chamber and high intraocular pressure (phacomorphic glaucoma). These eyes have positive vitreous pressure, and anterior chamber formation with an ophthalmic viscosurgical device may not be possible. Surgery is difficult and prone to various intraoperative complications.     

Visualizing the vitreous body in the anterior chamber using 11-deoxycortisol after posterior capsule rupture in an animal model

OBJECTIVE: To develop a new technique to visualize vitreous body prolapsed in the anterior chamber using 11-deoxycortisol. STUDY DESIGN: Experimental study. METHODS: An animal model of posterior capsule rupture was developed to investigate the usefulness of 11-deoxycortisol, a precursor of cortisol without steroid activity. After the intentional creation of posterior capsule rupture, the suspension of 11-deoxycortisol was injected into the anterior chamber of rabbit eyes. After gentle irrigation and aspiration, the vitreous body that had prolapsed into the anterior chamber was removed using an anterior vitrectomy cutter. To investigate the safety of 11-deoxycortisol, the biomicroscopic appearance, intraocular pressure (IOP), corneal endothelial count, and microstructure of the corneal endothelium were examined in the rabbits that received injections of 11-deoxycortisol in the anterior chamber. RESULTS: In our posterior capsule rupture model, the vitreous in the anterior chamber became clearly visible, with 11-deoxycortisol showing white particles entrapped on its surface. The injection of 11-deoxycortisol facilitated the complete removal of the vitreous body from the anterior chamber. In intact rabbit eyes, most of the injected 11-deoxycortisol had disappeared from the anterior chamber by 12 hours after injection. The injection of 11-deoxycortisol had no effect on IOP, corneal endothelial density, or the microstructure of the corneal endothelium. CONCLUSIONS: The injection of 11-deoxycortisol in the anterior chamber is useful in visualizing the vitreous body and has no significant side effects. This technique might reduce the intraoperative and postoperative complications of anterior vitrectomy after posterior capsule rupture.     

Anterior chamber abnormalities and cataract

Material occurring in the anterior chamber as a result of trauma may be of little or major significance. The most common finding requiring treatment is hyphema. Close observation and (often surgical) treatment is especially important in patients at high risk: those with sickle cell disease, rebleeding, and elevated intraocular pressure. Cataract is a common complication in eyes sustaining serious trauma, although its presence may be difficult to confirm during the initial repair. The diagnosis is especially crucial because of the significantly increased risk of endophthalmitis. If the surgeon is able to determine that cataract is indeed present and hinders visualization of the posterior segment, or may lead to rapid elevation of the intraocular pressure, primary lens removal should be considered because vitreoretinal injuries are expected in approximately one-half of eyes, and an early retinal examination is mandatory in all eyes with lens trauma. Because one out of two eyes have posterior capsule injury, vitrectomy methods of lens removal are commonly required. Preservation of the posterior capsule is less important than avoiding traction on the anterior vitreous, because alternative methods of intraocular lens placement offer similar functional results.     

Vitreous Cinematography in the Study of Vitreoretinal Diseases

A new technique of vitreous cinematography involves scanning of the vitreous cavity using optical sections to provide objective, reproducible information on the dynamics of the posterior vitreous and vitreoretinal relationships. Using a newly developed preset lens (El Bayadi-Kajiura lens), this technique makes it possible to document an entire optical section of the posterior vitreous. This is done by mechanically displacing the vitreous so that maximum reflectivity can be obtained from the vitreous gel. This article describes the technique and presents clinical examples documenting complete and incomplete vitreous detachment in normal eyes, Cloquet's canal associated with an optic disc pit, vitreous traction associated with a lamellar hole in an area of preretinal macular fibrosis, and vitreous traction at the anterior flap of a retinal break.     

Posterior chamber intraocular lens supported by an intact vitreous face

We describe a technique of posterior chamber intraocular lens (IOL) implantation in eyes with inadequate capsule support caused by inadvertent or planned intracapsular cataract extraction (ICCE) or in eyes having secondary IOL implantation after previous ICCE. The procedure is only performed in eyes with an intact anterior vitreous face, no vitreous prolapse into the anterior chamber, and no vitreous loss. The anterior vitreous is pushed back by viscoelastic material or air. The viscoelastic material is injected under the iris to create a free space between the iris and anterior vitreous. A single-piece, C-loop, poly(methyl methacrylate) IOL is slid onto the iris to rest on the anterior vitreous face; care is taken not to disturb the anterior vitreous. The technique was used in 15 eyes with a follow-up from 19 months to 5 years. All eyes had a stable IOL at each follow-up, and the visual acuity was 6/12 or better at the last follow-up.