【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.     

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.     

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.     

Pseudo anterior capsule barrier for the management of posterior capsule rupture

A technique that uses an implanted intraocular lens (IOL) to create a barrier for the management of posterior capsule rupture is described. When a rupture occurs, surgery is halted and a dispersive ophthalmic viscosurgical device (OVD) injected into the anterior chamber to prevent vitreous prolapse. The remaining nucleus is maneuvered into the anterior chamber away from the pupillary space. The posterior capsule tear is converted into a continuous curvilinear capsulorhexis where possible. Dissociated anterior vitrectomy is performed as indicated, keeping the large nuclear fragments trapped in the OVD-filled anterior chamber. An IOL is implanted in the capsular bag or sulcus with optic capture through the anterior capsulorhexis. Using reduced parameters, phacoemulsification of the remaining fragments is completed over the IOL, which functions as a barrier to seal off the vitreous cavity. Residual nuclear fragments and vitreous are cleared from beneath the optic by placing the vitreous cutter under the optic, recapturing the optic before the instruments are removed from the eye. FINANCIAL DISCLOSURE: The author has no financial or proprietary interest in any material or method mentioned.     

Aurolab aqueous drainage implant in the vitreous cavity: Our modifications over the conventional technique of glaucoma implant surgery

Glaucoma drainage devices (GDDs) are used for managing refractory glaucoma due to failed trabeculectomy, neovascular glaucoma, traumatic glaucoma, and secondary glaucoma post keratoplasty. Aurolab aqueous drainage implant (AADI) is a nonvalved drainage implant conventionally implanted with the tube placed in the anterior chamber. Studies about the outcome of the various aqueous drainage devices implanted in the anterior chamber have reported complications such as tube extrusion, migration, blockage, erosion, and corneal decompensation. We propose modifying the conventional GDD implantation technique by placing the tube in the vitreous cavity, thereby negating the risk of anterior segment complications in patients with refractory glaucoma whose anterior segment is already compromised. Another novel approach implemented in this technique was making a scleral tunnel instead of using a scleral or corneal patch graft to cover the tube to prevent its migration. This article describes the surgical steps of this technique and its advantages, along with a surgical video.     

Ultrasound biomicroscopic analysis of posterior chamber intraocular lenses with transscleral sulcus suture

OBJECTIVE: To investigate the postoperative problems of intraocular lenses (IOLs) with transscleral sulcus suture. DESIGN: Retrospective observational case series. PARTICIPANTS: Forty-one subjects (43 eyes) were included. INTERVENTION: All eyes had undergone transscleral sulcus suture of IOLs. Surgeries were all performed by surgeons in our clinic using the same technique. MAIN OUTCOME MEASURES: Ultrasound biomicroscopy of the suture sites, their surrounding structures, and central anterior chamber depth. Other parameters studied included visual acuity, aqueous flare, and routine ophthalmic examinations. RESULTS: Thirty-two of 86 haptics were sutured at the ciliary sulcus (CS) region and 29 at the ciliary process region, which was the space between CS and pars plicata, and 25 posterior to pars plicata. We designated the cases with at least one haptic located in the CS region as the anterior group, and the other cases as the posterior group. In the anterior group, anterior chamber depth was significantly more shallow than in the fellow eye in which IOLs were fixed in the bag (P = 0.049). There was a statistically greater incidence of IOL iris contact in the anterior group than in the posterior group (P = 0.00057). Pigment dispersion was seen in seven cases, all of which were classified as anterior group. Eyes in the posterior group had more aqueous flare than their fellow eyes (P = 0.014). Two cases, in which more than two lines of postoperative best-corrected visual acuity was lost because of macular degeneration after cystoid macular edema, showed marked elevation of aqueous flare in the sutured eyes compared with their fellow eyes. Forty-one of 86 haptics had vitreous incarceration. CONCLUSIONS: This technique has many limitations: the difficulty of suturing precisely at the ciliary sulcus, IOL iris contact, pigment dispersion, high aqueous flare, and vitreous incarceration. These induce two major postoperative complications: chronic inflammation and influence on the adjacent vitreous such as vitreous incarceration. The suturing technique and instruments need to be improved to diminish such complications.     

Clinical application of 11-deoxycortisol in visualizing prolapsed vitreous body after posterior capsule rupture in cataract surgery

PURPOSE: To evaluate the clinical usefulness of 11-deoxycortisol, a precursor of cortisol in steroid metabolism, in visualizing the vitreous body in the anterior chamber after posterior capsule rupture during cataract surgery. SETTING: Department of Ophthalmology, Tsukuba University Hospital, Ibaraki, Japan. METHODS: Eight eyes had anterior vitrectomy during cataract surgery using this new technique. A suspension of 11-deoxycortisol was prepared by dilution in balanced salt solution without preservatives or emulsifying agents. After a posterior capsule rupture, the suspension was injected into the anterior chamber. The visual and anatomical outcomes of surgery were evaluated during a follow-up of 7 to 9 months. RESULTS: After the 11-deoxycortisol injection, the vitreous body that had prolapsed through the torn posterior capsule, with white particles entrapped on its surface, became clearly visible. Complete removal of the prolapsed vitreous body was achieved easily and safely using an anterior vitrectomy system. No postoperative complications related to the use of 11-deoxycortisol were observed. CONCLUSION: Injection of 11-deoxycortisol helped visualize the vitreous body in the anterior chamber after posterior capsule rupture. The technique minimized intraoperative and postoperative complications related to posterior capsule rupture and vitreous loss during cataract surgery [corrected]     

Use of perfluorocarbon solutions in the surgical treatment of posterior luxation of the lens]

Posterior lens dislocations represent 20 to 40% of all lens dislocations. It can occur after trauma. Visual prognosis can be good, but most often there are complications such as glaucoma, retinal detachment and uveitis. A few years ago, surgery was difficult, and surgery was delayed until the development of specific complications. A new technique, using perfluorocarbon liquids (PFCL), should be recommended because it is simple, and constantly effective. After vitrectomy, perfluorodecalin is injected into the vitreous cavity. As PFCL have a density twice the density of water, it allows the lens to float on the surface of the PFCL, behind the iris. Lens extraction can be associated with trabeculectomy, and anterior chamber lens implantation. We present a prospective study of 6 cases operated according to this technique. Postoperative results were good: visual acuity was preserved and ocular tension was controlled in cases of preoperative hypertonia. We believe this technique can be recommended after posterior lens dislocation, to prevent complications and to preserve visual acuity.     

Eye trauma in childhood and youth

Childhood trauma of the eye and its adnexa represents approx. 4 - 20 % of all eye injuries. Due to ambiguous patient history and limited cooperation a comprehensive diagnosis of pediatric eye trauma is often difficult. The weakness of the infantile cornea, the thin and elastic anterior lens capsule, and the firm vitreous with its strong adherence to the retina bear particular intra- or postoperative problems. Moreover, the quick development of secondary cataract and the high risk of PVR may complicate the posttraumatic and postoperative course. Small infants represent a special subgroup in various regards mainly because of the risk of amblyopia which often causes functional loss in spite of a good anatomical reconstruction. The relative frequency of certain injuries differs between children and adults. The ocular manifestation of child abuse as well as bite and fireworks injuries are characteristic for childhood and will be discussed more in detail.     

Therapeutic lamellar keratoplasty with an automated microkeratome

Penetrating keratoplasty (PKP) is the predominant form of corneal transplantation because both manual and automated lamellar keratoplasty are technically difficult and lead to complications such as irregularities and scarring. A microkeratome for laser in situ keratomileusis can be used to overcome these disadvantages. We describe a technique of lamellar keratoplasty performed with an automated microkeratome to treat corneal opacities in the anterior third of the cornea. This easy, accurate technique leads to good visual results and represents a good alternative to PKP in treating anterior corneal opacities.     

Gas-mediated vitreous compression: an experimental alternative to mechanized vitrectomy

We have developed a simple technique in rabbit and baboon eyes that utilizes intravitreally injected perfluoropropane gas, which expands slowly to efficiently compress and displace nearly completely the vitreous body. There is cataract formation after extended contact of the gas bubble with the lens. However, it is rapidly reversible by reducing the duration of lens contact (gas-fluid exchange) and by using young animals. No long-term alterations in intraocular pressure or retinal function were observed, as determined by electroretinography, during the 4-month test period.Gross examination and scanning electron microscopy revealed that the vitreous cavity, shortly after full expansion of the gas bubble, was practically free of collagen. The vitreous body had been detached from most of the retina and compressed into a collagenous strand between the optic nerve head and lens in the rabbit eyes, and there was also a dense collagen accummulation on the inferior retinal surface and anterior vitreous base in the rabbits and the baboon. Large areas of the retina and medullary wings were stripped of overlying collagen. By the end of 4 months, the compressed vitreous body had expanded to become an irregular structure that remained separated from the retina in areas of previous detachment.Mechanized vitrectomy is a difficult procedure often needed in experimental work. We believe that the vitreous compression and gas-fluid exchange technique is a valid alterative to a mechanical approach. We also believe that we have a model that simulates the human situation of posterior vitreous detachment and vitreous syneresis.This study was supported by a grant to M.E. from the Retina Research Foundation, Houston, Texas, by Grant EY02903 and the Helena Rubinstein Foundation, New York from the National Eye Institute to R.M., and by a grant to M.E. from Research to Prevent Blindness, Inc., New York, New YorkPresented at Association for Research in Vision and Ophthalmology, Sarasota Fla, May 2–5, 1983     

Device drug delivery to the eye. Collagen shields, iontophoresis, and pumps

External devices have been used to enhance drug delivery. This article reviews the role of collagen shields, iontophoresis, and pumps used to deliver ophthalmic medications. Collagen shields have been used to deliver drugs and promote corneal epithelial healing. Presoaked collagen shields deliver many drugs to the eye as well as or better than traditional methods such as frequent topical therapy or subconjunctival injection. The efficacy of drug delivery by collagen shields was demonstrated in animal models of graft rejection and bacterial keratitis. Iontophoresis uses an electrical current to carry an ionized drug across tissue. Transcorneal iontophoresis delivers high concentrations of a drug to the anterior segment of the eye. Transscleral iontophoresis bypasses the lens-iris diaphragm and produces adequate vitreous levels. Pumps deliver fluid to the eye for extended periods of time via a tube with its distal opening in the conjunctival sac, corneal stroma, anterior chamber, or vitreous cavity. Clinical acceptance of the collagen shield for drug delivery to the anterior segment is better than iontophoresis or pumps, probably because the collagen shield is simpler and more convenient to use.     

Management of vitreous loss during cataract surgery under topical anesthesia with transconjunctival vitrectomy system

PURPOSE: A new technique to manage posterior capsular rupture with vitreous prolapse into the anterior chamber during phacoemulsification under topical anesthesia using the sutureless self-sealing 25-gauge transconjuctival vitrectomy system. METHOD: In the event of vitreous prolapse into the anterior chamber, the corneal wound is sutured and cleared of vitreous. A trans conjunctival 25-gauge sclerotomy through the pars plana is made. The high speed 25-guage trans-conjunctival vitrectomy system (TVS-25) under topical anesthesia is introduced and vitrectomy is performed to clear the anterior chamber of vitreous. An anterior vitrectomy is also done. A foldable intraocular lens is subsequently inserted. RESULTS: The vitrectomy is performed in a closed chamber maintaining normal intraocular pressure. The high-speed cutter exerts minimal traction on the vitreous. The accessibility to vitreous improves through the pars plana route ensuring more complete removal of the vitreous and restoration of normal anatomy. Topical anesthesia avoids the risks of globe perforation, retrobulbar hemorrhage, and prolonged postoperative akinesia of the eye. CONCLUSIONS: The 25-gauge pars plana incision is small and self-sealing. This makes the procedure fast, effective, painless and safe.