Anterior Chamber Maintainer Research Articles

Audit of small-incision cataract surgery using an anterior chamber maintainer.

To assess the results of small-incision cataract surgery with intraocular lens implantation using an anterior chamber maintainer (ACM) performed between March 1997 and December 1998. A retrospective audit was performed of all 300 consecutive patients who underwent extracapsular cataract extraction using a 6 mm scleral tunnel incision, anterior chamber maintainer and manual fragmentation of the nucleus. Ninety per cent of patients had a gain in visual acuity at the end of 3 months. The rate of posterior capsule opacification was comparable to the results of the National Cataract Surgery Survey (RCO 1993), i.e. 13%, but the rate of corneal endothelial decompensation and endophthalmitis was marginally higher. Appropriate selection of cases, meticulous wound closure and subconjunctival antibiotics at the end of surgery make this an acceptable alternative small-incision closed-system low-cost procedure where phacoemulsification is not available.

Ocular findings in Sturge-Weber syndrome.

We reviewed the rare ocular findings of Sturge-Weber syndrome (SWS) and the results of implantation of the Ahmed valve in cases associated with glaucoma. Seven patients (range 18 to 52 years) diagnosed as SWS were reviewed as clinical findings over two years. An anterior chamber maintainer was placed in patients with glaucoma to maintain stable intraocular pressure and minimize the risk of intraocular hemorrhage due to sudden pressure changes during surgery, when an Ahmed valve is implanted. Episcleral venous vessels were prominent in all cases. Diffuse choroidal hemangiomas were seen in three cases. Nevus of Ota was observed in only one case. Three cases had juvenile glaucoma. One also had buphthalmos. No intraocular hemorrhage or choroidal effusion was observed intraoperatively in valve-implant patients. The surgical treatment of the patients with glaucoma gave favorable outcomes. Rare ocular findings such as choroidal hemangioma and nevus of Ota are sometimes seen in SWS. Drainage valve implantation, with an anterior chamber maintainer, is a good choice for treatment when surgery is done in cases with glaucoma. This method may reduce the risk of intraoperative suprachoroidal effusion and expulsive hemorrhage by stabilizing intraocular pressure within normal limits during the surgery.

Suprachoroidal Hemorrhage During Silicone Oil Removal in Marfan Syndrome

A 30-year-old male with Marfan syndrome underwent pars plana lensectomy and vitrectomy combined with silicone oil injection for the treatment of retinal detachment with proliferative vitreoretinopathy (PVR). Four months after vitrectomy, the silicone oil was removed using an anterior chamber maintainer (AC) and a self-sealing clear corneal incision at the upper temporal quadrant. Suprachoroidal hemorrhage (SCH) developed at the end of the operation. It was limited to the nasal side of the retina. Suprachoroidal hemorrhage remained to be limited and did not show progression.

Results of small incision extracapsular cataract surgery using the anterior chamber maintainer without viscoelastic

AIMSTo assess the efficacy of extracapsular cataract surgery using the anterior chamber maintainer (ACM) without the use of viscoelastic. To compare the effects of this surgical technique on non-diabetic and...

Experimental studies on viscofluids for intraocular surgery

Purpose: To investigate the feasibility and efficacy of using diluted viscofluids during intraocular surgery.Setting: Laboratory for Intraocular Microsurgery and Implants, Goldschleger -Eye Research Institute, and the Sackler School of Medicine, Tel-Hashomer, Israel.Methods: Diluted hyaluronic acid (0.06 to 0.12%) in balanced salt solutions were irrigated through the phacoemulsification machine or a separate irrigation line (i.e., anterior chamber maintainer). Irrigation was facilitated by increasing the atmospheric pressure in the bottle using compressed air. Experimental surgery was done in rabbit eyes.Results: A viscous fluid could be irrigated at any practical rate by increasing the height of the bottle, increasing the atmospheric pressure within the bottle, or both. Experimental surgeries showed that viscofluids maintained intraocular pressure and anterior chamber volume, allowed safe intraocular manipulations, reduced turbulence in the anterior chamber, and probably provided tissue protection.Conclusion: Viscofluids irrigated using a high-pressure system combined the advantages of continuous irrigation of fluids and the protective qualities of viscoelastics in this rabbit eye study.

Preventing expulsive hemorrhage using an anterior chamber maintainer to eliminate hypotony

We describe a method in which constant infusion inflow through an anterior chamber maintainer (ACM) is used to maintain positive intraocular pressure (IOP) during cataract extraction through a self-sealing tunnel incision. A retrospective review of patient records showed that the difference in the incidence of intraoperative suprachoroidal hemorrhage was significantly greater in eyes in which IOP was not constant throughout surgery than in eyes in which IOP was maintained using the ACM system.

Cataract surgery in Fuchs' heterochromic iridocyclitis.

To assess the particularities of extracapsular cataract extraction and posterior chamber intraocular lens implantation in patients with Fuchs' heterochromic iridocyclitis. Retrospective analysis of 24 extracapsular cataract operations performed from September 1991 to June 1994. Our technique-a slight modification of Blumenthal's technique-included a triplanar watertight small scleral incision, an envelope capsulotomy, nucleus hydrodissection and hydroexpression, anterior chamber maintainer use, thorough residual cortex removal through a side-port corneal incision and "in the bag" posterior chamber intraocular lens implantation. Mydriasis was slightly larger than 5 mm in 79.16% of the total group. Posterior capsule rupture with vitreous loss occurred in one and without in two patients. A transient rise in intraocular pressure was seen in seven patients and a mild anterior chamber reaction in almost all patients. No bleeding occurred during anterior chamber opening, or postoperative I.O.L. decentration or glaucoma. Best corrected postoperative visual acuity ranged from 5-10/10 in 21 patients (87.50%). Extracapsular cataract extraction in patients with Fuchs' heterochromic iridocyclitis does not currently present any difficulties compared with normal senile cataract. No major complications occurred and the final visual acuity was satisfactory.

Diamond-tip versus blunt-tip caliper enlargement of clear corneal incisions

Purpose: To assess corneal trauma after clear corneal incision (CCI) enlargement with a diamond-tip versus a blunt-tip caliper.Setting: University of Vienna, Austria.Methods: Human bulbi obtained from the eye bank of the University of Vienna had a 3.0 mm single-plane CCI enlarged to 5.0 mm using either a diamond-tip or a blunt-tip adjustable caliper. During the process, eye pressure was kept between 22 and 25 mm Hg by infusing balanced salt solution using an anterior chamber maintainer. Light, scanning electron, and transmission electron microscopy were performed according to standard procedures.Results: Incisions enlarged with the diamond-tip caliper were well-defined and allowed good closure of the wound lips. In contrast, the blunt-tip caliper produced widened, drumstick-shaped recesses at the lateral ends of the incisions. Adjacent to these recesses, the collagen lamellae were severely dislocated and torn.Conclusion: Cutting the corneal tissue with diamond tips caused less tissue damage than expanding it with blunt tips. It was not possible to temporarily widen incisions using a blunt-tip caliper without significantly intensifying tissue damage.

Prevention and management of posterior capsule rupture.

To present the means and technique used in our Department for prevention and management of posterior capsule rupture during planned extracapsular cataract extraction. Prospective analysis of 550 extracapsular cataract operations from October 1993 to March 1994. Our technique (a slight modification of Blumenthal's technique) included a triplanar watertight small scleral incision, a relatively large continuous curvilinear capsulorhexis, or can-opener capsulotomy, nucleus hydrodissection and hydroexpression, use of an anterior chamber maintainer and residual cortex removal through a 10 o'clock side-port corneal incision. Best corrected postoperative visual acuity ranged from 7-10/10 in 93.45% of our cases. Posterior capsule rupture with or without vitreous loss occurred in 1.63% and 2.72% of the cases, respectively. These rates are much lower than those, observed, when we used the sclerocorneal incision and nucleus extraction with external pressure. The combination of a triplanar watertight small scleral incision. A relatively large continuous curvilinear capsulorhexis, an anterior chamber maintainer and residual cortex aspiration through the 10 o'clock side-port corneal incision greatly reduced the posterior capsule rupture rate.

Anterior Chamber Maintenance During Drainage of a Suprachoroidal Hemorrhage in Two Phakic Eyes

The authors describe a technique for hemorrhage drainage following glaucoma surgery that uses an anterior chamber maintainer to minimize risk to the anterior lens capsule. Two patients had suprachoroidal hemorrhages following filtration surgery. Because their eyes were phakic, an anterior chamber maintainer, as opposed to a 23-gauge butterfly needle, was used for aqueous replacement during hemorrhage drainage. The maintainer provided a stable anterior chamber environment during both drainage procedures. No damage to anterior chamber structures occurred, and the postoperative course was unremarkable in both patients. The use of a sharp-tipped infusion cannula may be contraindicated for the phakic patient who has a suprachoroidal hemorrhage. The anterior chamber maintainer is a useful alternative instrument in such cases.

Use of the anterior chamber maintainer in anterior segment surgery

Over a 12 month period, we used the anterior chamber maintainer (ACM) in cataract surgery in 258 patients; ages ranged from 15 to 95 years (mean 73 years). Surgery was performed using general or local anesthesia. The procedures were standard extracapsular cataract extraction (ECCE), mini-nuc ECCE, vectis extraction of the endonucleus, manual phacofragmentation, phacoemulsification, phacotrabeculectomy, repositioning the IOL, and anterior segment revision. We recorded our subjective assessment of the degree of anterior chamber (AC) maintenance and control of the position of the posterior capsule during surgery. We also kept clinical notes of the practical aspects of the procedures. The AC was well maintained in all patients throughout the surgery; posterior position of the posterior capsule was maintained during irrigation/aspiration. Five patients required the use of a viscoelastic agent at some stage. Our subjective assessment is that use of the ACM increased surgical control of the anterior chamber depth and position of the posterior capsule during surgery. Provided that it is used correctly, the ACM may offer increased safety during anterior segment surgery and require less use of viscoelastic agents.

Implantation of a Staar silicone intraocular lens with the anterior chamber maintainer

A method for performing phacoemulsification and implantation of a foldable lens (Staar AA 4203) with an anterior chamber maintainer is described. The procedure eliminates the need for viscoelastics, preventing postoperative pressure elevation and reducing costs. The incision is kept sealed during the implantation with the injector, and the anterior chamber remains deep. Making a small incision under positive intraocular pressure prevents the development of high astigmatism. I have implanted more than 500 lenses using this method, with very good results.

Manual ECCE, the present state of the art.

Manual ECCE has proved to be safe surgery compatible with small incision, no stitches, possible topical anesthesia, very cost effective and quick rehabilitation. The technique has a learning curve and needs experience. "Mini-nuc" stands for mini nucleus. This surgery can be achieved only if performed under positive intraocular pressure (IOP). A BSS bottle is connected to the eye by an anterior chamber maintainer (ACM). The height of the BSS bottle controls the IOP during the surgery. Controlled IOP is a principle suggested for all kinds of cataract surgery. It creates continuous flow which washes out of the eye cortex debris, blood, pigment, etc. The BSS contains antibiotics and adrenalin, it creates low turbulence due to the small amount of BSS used per case, 30-50 cc. A round capsulorhexis is essential. A special way of hydrodissection creates a very small hard core nucleus delivered to the anterior chamber and is extracted out through a sclero-corneal tunnel using a glide introduced under the nucleus to guide the nucleus out. Positive IOP during all stages of surgery creates the best operative conditions for controlled surgery throughout all manipulations. This technique is a very cost effective system and at the same time provides a high quality procedure.

Using an anterior chamber maintainer to control intraocular pressure during phacoemulsification

We describe a phacoemulsification technique that uses an anterior chamber maintainer (ACM) to control intraocular pressure. Continuous irrigation through the ACM maintains pressurized intraocular conditions throughout surgery and when the automated system is not activated. Intraocular pressure is stabilized at predetermined levels with minor fluctuations. Viscoelastics can be used in conjunction with the ACM.

Hydroexpression of Subluxated Lenses Using a Glide

During the past 8 years, 15 patients (20 eyes) underwent a variety of operations to remove a subluxated lens. In six of these eyes, a new technique, featuring an anterior chamber maintainer and a plastic glide, was used for intracapsular cataract extraction (ICCE). The results achieved in these eyes were compared with those in 8 eyes in which cryo extraction was used, in 1 in which pars plana lensectomy was used, in 4 in which aspiration of lens material and peeling of the capsule was used, and in 1 in which a viscoelastic material and spatula were used. Using the glide, the lens is extracted through a scleral tunnel incision or a limbal opening. The length of the opening is somewhat smaller than the diameter of the lens and is significantly smaller than that used in traditional ICCE. The visual outcomes achieved with these various techniques were essentially identical. The proposed technique is simple and relatively safe for these complicated cases.

Cataract extraction in eyes filled with silicone oil.

A surgical technique for cataract extraction in eyes filled with silicone oil was developed that has two major objectives: removal of the entire cataractous lens and complete preservation of the silicone oil volume. A regular extracapsular cataract extraction or phacoemulsification is performed, and the incision is closed with the final sutures. All steps are performed under continuous positive pressure achieved with an anterior chamber maintainer connected to a bottle of balanced saline solution. An inferior basal iridectomy is created with a vitrectomy probe, and the posterior capsule is then slowly pulled out through the limbal incision with intraocular forceps, again under positive pressure, in an eye that is actually a closed system, without any loss of silicone. This step results in transformation of the extracapsular cataract extraction condition into an intracapsular cataract extraction condition. The described technique was successfully performed in nine eyes. In the younger patients, the whole procedure was completed through two very small limbal openings.

Trabeculectomy with anterior vitrectomy in aphakic and pseudophakic glaucoma

In 15 eyes with uncontrolled aphakic/pseudophakic glaucoma, trabeculectomy with anterior vitrectomy was performed. Mean pre-operative intraocular pressure (IOP) was 38.2 +/- 6.7 mmHg and mean post operative IOP was 19.3 +/- 5.2 mmHg after follow-up of 11.2 2 months. The anterior chamber maintainer technique during vitrectomy has been employed. Success rate (IOP less than 21 mmHg with or without glaucoma medication) was 80%. Visual acuity remained unchanged in 4 eyes, improved in 5 eyes and worsened in 6 eyes. Postoperative complications included: two eyes with cystoid macular edema, two eyes with choroidal effusion and prolonged hypotony, one eye with self-absorbing vitreous hemorrhage and one eye with some opacification of the corneal graft. In aphakic/pseudophakic glaucoma where vitreous is filling the anterior chamber--a combined trabeculectomy with anterior vitrectomy is indicated for removal of vitreous from the sclerostomy site with better aqueous flow through the sclerostomy and adequate control of IOP.

Lens anatomical principles and their technical implications in cataract surgery Part I: The lens capsule

Optimal fixation and position of an intraocular lens (IOL) is achieved when it is located in the capsular bag. A peripheral tear from the central opening to the lens periphery is associated with a high incidence of dislocation of at least one loop from within the capsular bag and lens decentration. A central round continuous capsulectomy (capsulorhexis), within the zonule-free area, provides long-term and balanced IOL fixation. To perform a well-controlled capsulectomy, a deep and stable anterior chamber should be maintained throughout the surgery. This is achieved by using a continuous anterior chamber maintainer that regulates the pressure in the anterior chamber. This paper reviews the clinical anatomical guidelines of the lens capsule and the anterior chamber and presents the authors' preferred technique for optimal anterior capsulectomy.

Lens anatomical principles and their technical implications in cataract surgery Part II: The lens nucleus

Preservation of the intact (“true”) capsular bag, with no tears to the periphery, is essential to assure permanent in-the-bag fixation of the intraocular lens. Removal of a large nucleus using the open-system planned extracapsular cataract extraction (ECCE) technique is often associated with tearing of the capsulectomy or serious complications such as zonular rupture, vitreous loss, unintended intracapsular cataract extraction, or posterior lens prolapse. A closed-system planned ECCE technique which allows a safe removal of the lens while maintaining the integrity of the capsular bag is presented. Hydrodissection of the lens nucleus to an epinucleus and a central hard nucleus allows hydroextraction of the small hard core while pushing the posterior capsule backward. The positive pressure in the anterior chamber, provided by the anterior chamber maintainer, keeps the position of the lens steady in its natural location, and minimizes the stress on the zonular apparatus during nucleus delivery. The remaining epinucleus can be either hydroexpressed or aspirated. Fracturing the central core, when possible, enables removal of the lens material through a small limbal incision. Viscoelastic material can be combined with a low-flow, anterior chamber maintainer in a closed-system and provides a useful surgical tool.

The Round Capsulorhexis Capsulotomy and the Rationale for 11.0 mm Diameter IOL

It is generally accepted that the optimal location of the IOL is in the capsular bag. This location is advantageous only if the IOL remains permanently in the capsular bag. The anatomical factors directing guidelines for a 5.0–6.0 mm round capsulotomy are: anterior posterior position of the crystalline lens, zonular frontier and zonular pull. To express the nucleus without the danger of capsular tears, use of the closed system technique which permanently maintains the volume and the pressure by using an anterior chamber maintainer is recommended. Thus hydrodissection and hydroexpression of the nucleus through small limbal incision are facilitated, without tear at the capsulotomy margin. The dimension of the crystalline capsular bag changes from 9.6 mm to 10.7 mm after ECCE. Thus 11.0 mm loop-to-loop lenses are advocated. Uncertainty about secure ‘in the bag’ implantation is the reason for the use of 13.0–14.0 mm lenses at present. As more surgeons are mastering round capsulorhexis capsulotomy, a greater number will find it safe to use 11.0 mm new design lenses with asymmetrical loops. In fact, there would be no reason not to implant 11.0 mm lenses.