Yokrat Ton

Capsule anchor to manage subluxated lenses: Initial clinical experience

PURPOSE: To evaluate the use of a capsule anchor to reposition and fixate the capsular bag to the scleral wall in eyes with subluxation of the crystalline lens. SETTING: Department of Ophthalmology, Meir Medical Center, Kfar‐Saba, Israel. METHODS: This study evaluated a 1‐plane poly(methyl methacrylate) intraocular implant (Capsular Anchor) that is clipped to the anterior capsule to support it. The device is composed of a central rod located in front of the anterior capsule and 2 lateral arms positioned behind the anterior capsule. The anchor is secured to the sclera with a single 9‐0 or 10‐0 polypropylene suture. A capsular tension ring (CTR) can be implanted in conjunction with the anchor. The anchor was implanted in eyes with subluxated cataractous lenses. After surgery, intraocular lens (IOL) centration and corrected distance visual acuity (CDVA) were monitored for 12 months. RESULTS: The anchor was successfully implanted in 2 patients with traumatic subluxated lenses and 2 patients with Marfan syndrome. In 1 eye, 2 anchors were used because of zonular dehiscence that extended during surgery. In 3 eyes, an IOL was implanted in the bag and in 1 eye, in the sulcus. A CTR was additionally implanted in 3 eyes. During the 12‐month follow‐up, the IOLs remained well centered and stable. The CDVA improved to 20/20 to 20/25 in all cases. CONCLUSION: The capsule anchor was effective in fixating the lens capsule to the scleral wall in cases of significant zonular dehiscence.

CO2 laser-assisted sclerectomy surgery, part II: multicenter clinical preliminary study.

PurposeTo evaluate the efficacy of CO2 laser-assisted sclerectomy surgery (CLASS) in primary and pseudoexfoliative open-angle glaucoma. Materials and MethodsPatients for primary filtration surgery underwent CLASS with a CO2 laser system (OT-134-IOPtiMate, IOPtima Ltd., Ramat Gan, Israel). This self-controlled system gradually ablates and removes scleral layers until percolating fluid absorbs the energy, attenuating further tissue ablation. Intraocular pressure (IOP) was measured at baseline, 1, 2, 4, and 6 weeks, and 3, 6, and 12 months, respectively. Complete success was defined as 5⩽IOP⩽18 mm Hg and 20% IOP reduction with no medication at a 12-month endpoint visit, and qualified success as the same IOP range with or without medication. ResultsThirty of 37 patients completed 12 months of follow-up. Mitomycin C was used in 25 procedures (83.3%). The mean baseline IOP of 26.3±7.8 mm Hg (mean±SD) dropped to 14.4±3.4 and 14.3±3.1 mm Hg at 6 and 12 months, respectively, with 42.4% and 40.7% IOP reduction at 6 and 12 months, respectively (P<0.001). Complete success was achieved by 76.7% and 60% of the patients at 6 and 12 months, respectively, whereas qualified success was achieved by 83.3% and 86.6% of the patients at 6 and 12 months, respectively. Complications were mild and transitory with no sequela. ConclusionsShort-term and intermediate results suggest that CLASS may become a simple, safe, and effective means of choice for the treatment of open-angle glaucoma.

Prognostic factors for visual acuity improvement after intravitreal triamcinolone injection

PurposeIn some patients with macular oedema, intravitreal triamcinolone acetonide injection (IVTA) fails to improve visual acuity, although oedema shows clinical and angiographic improvement. Side effects can include increased intraocular pressure, cataract development, and (rarely) endophthalmitis. Our purpose was to identify prognostic factors for visual acuity improvement after IVTA.MethodsData on patients treated by IVTA for macular oedema were retrospectively reviewed. Three months postinjection, visual acuity was rated as ‘improved’ (two or more Snellen lines gained) or ‘nonimproved’ (unchanged or worsened). Comparative demographic data and pre- and post-IVTA clinical and fluorescein angiographic findings were analysed with SPSS software.ResultsOf 57 eyes (57 patients), 27 (47%) improved after IVTA. Initial visual acuity (‘good’, ‘moderate’, or ‘poor’) and aetiology of macular oedema (diabetic, venous occlusion, or pseudophakic) did not differ between the two groups. Improvement occurred in significantly more eyes with clinical or angiographic evidence of cystoid macular oedema (CME) than in those with diffuse retinal thickening (P=0.04) or diffuse leakage on fluorescein angiography (P=0.02), respectively, and in significantly more pseudophakic than phakic eyes (P=0.046).ConclusionsPseudophakia and clinical or angiographic CME, but not aetiology or initial visual acuity, were prognostic of visual acuity improvement after IVTA for macular oedema.

CO2 laser-assisted sclerectomy surgery part I: concept and experimental models.

PurposeTo evaluate the safety and performance of a second-generation device for CO2 laser-assisted sclerectomy surgery system in experimental models. Materials and MethodsLaser-assisted deep sclerectomy using a modified CO2 laser system (OT-134—“IOPtiMate”; IOPtima Ltd, Israel) was performed in 3 experimental models: enucleated pig eyes, human cadaver eyes, and live rabbit eyes. A half-thickness scleral flap was created, and a CO2 laser with a beam-manipulating system was used to achieve deep scleral ablation over the Schlemm canal zone. Aqueous percolation and scleral perforation rates were recorded. Intraocular pressure was monitored in live rabbits up to 21 days postoperatively. The shape and location of the scleral ablation zone, thermal damage, and the healing process were examined by histopathological analysis. ResultsDeep scleral ablation and aqueous percolation were repeatedly achieved in all the models. Micro-perforations occurred in 4/18 human eyes (22.2%), in 4/23 rabbit eyes (17.4%), and in none of the 38 porcine eyes. Mean intraocular pressure in the rabbits was significantly decreased (by 6.3±3.6 mm Hg) on the first postoperative day (P<0.0001) and gradually returned to normal. In all but one of the cadaver eyes, effective fluid percolation was achieved. Histology in each case disclosed deep scleral craters with a thin intact sclero-corneal tissue layer at the ablation area. Mild thermal damage, limited to the ablated scleral walls was detected and resolved after 10 days. ConclusionsThe results in these experimental studies indicated that CO2 laser-assisted sclerectomy surgery using the OT-134 system is a safe and efficacious procedure for achieving effective fluid percolation.

Repositioning and scleral fixation of the subluxated lens capsule using an intraocular anchoring device in experimental models

PURPOSE: To describe a new device for repositioning and scleral fixation of the capsular bag of subluxated lenses in experimental models. SETTING: Laboratory for Experimental Microsurgery, Meir Medical Center, Kfar‐Saba, Israel. METHODS: The capsular anchoring device is a poly(methyl methacrylate) 1‐plane implant consisting of 2 handles that grasp the edges of the capsulorhexis and a base for scleral fixation with a single 10‐0 or 9‐0 polypropylene suture. A temporary safety suture can be used to facilitate manipulations and prevent loss of the device through the zonular defect until it is secured to the scleral wall. The device was implanted in porcine eyes and living rabbit eyes. An animal model of lens subluxation was achieved by tearing about one third of the zonules. Capsule centration, implant stability, and inflammatory reaction were evaluated 2 to 4 weeks after implantation in the living model. RESULTS: The device was implanted in 7 porcine eyes and 9 living rabbit eyes. A lens subluxation model was created in 4 porcine eyes and 2 rabbit eyes. The device effectively pulled the capsular bag to the center and remained stable up to 4 weeks thereafter. Very large zonular dialysis (>5 hours) was managed using 2 devices. Successful intraocular lens implantation was done repeatedly in the presence of the device. The implant was well tolerated in all rabbit eyes. Histopathological examination of the enucleated eyes revealed no inflammatory reaction or adhesions. The margin of the anterior capsulorhexis remained intact in all cases. CONCLUSIONS: Experimental studies of a capsular anchoring device for subluxated lenses confirmed the safety and efficacy of the new device. A capsular tension ring can also be inserted separately to further stabilize the capsular bag.

Management of subluxated capsular bag–fixated intraocular lenses using a capsular anchor

&NA; We describe the use of the capsular anchor (AssiAnchor) to manage a subluxated intraocular lens (IOL) in the capsular bag. The anchor comprises 2 prongs that hold the anterior lens capsule and a central rod that is sutured to the scleral wall, enabling centration of the IOL–capsular bag complex. Six pseudophakic patients presenting with subluxated posterior chamber IOLs in the capsular bag were operated on using the device. The anchor was used successfully in all cases, although in 2 cases only 1 prong was placed under the capsulorhexis edge. In 1 eye, 2 anchors were used 1 month apart following repeated traumatic zonular injury. The capsular bag holding the IOL remained centered and stable throughout the follow‐up period. The anchoring device, which was originally designed to preserve the lens capsule and stabilize subluxated crystalline lenses, can also be used to treat subluxation of a capsular bag–fixated IOL. Financial Disclosure Dr. Assia is the inventor of the AssiAnchor, has a licensed patent of the anchor, and is consultant to Hanita Lenses. Dr. Lapid‐Gortzak is a consultant to and speaker for Alcon Surgical, Inc., Hanita Lenses, Orca Surgical, and Sanoculis Ltd.; a speaker for Santen; and a consultant to Icon. Drs. Ton and Naftali have no financial or proprietary interest in any material or method mentioned.

Sutured Scleral-Fixated Intraocular Lens in Posterior Capsular Rent

Intraocular lens (IOL) implantation in cases lacking sufficient capsular support is challenging to the anterior segment surgeon. If the anterior capsule is intact and with no tears at the capsulorhexis margin, then a sulcus fixation is preferred by most surgeons; however, square-edged one-piece hydrophobic lenses should be avoided. If there is no capsular support to ascertain stable fixation, then other alternatives are used, such as scleral fixation of a three-piece IOL, either by suturing or by placing the haptics in a scleral tunnel, iris fixation using sutures or iris claw lenses, and anterior chamber angle supported IOLs.

Performing accurate CO2 laser-assisted sclerectomy surgery

Most glaucoma surgeries achieve intraocular pressure (IOP) reduction by penetrating the sclerotrabecular wall. Deep sclerectomy surgery aims to enhance aqueous drainage without penetrating the globe and also aims to avoid some of the severe complications associated with violating ocular integrity; however, this procedure is difficult to perform manually in a safe and effective way. CO2 laser has been suggested as a tool to facilitate deep, effective ablation over the ocular drainage system to reduce IOP without penetrating the eyeball in a procedure called CO2 laser-assisted sclerectomy surgery. In this study, the authors report the rationale of choosing this type of laser, the development of the laser delivery and control systems (IOPtiMate; IOPtima, Tel Aviv, Israel) and the experimental and clinical experience to date.

CO 2 Laser-assisted Sclerectomy Surgery for Open-angle Glaucoma

Purpose: To evaluate the safety and performance of CO2 laser-assisted sclerectomy surgery (CLASS). Materials and Methods: CLASS using the IOPtiMate™ system was performed in experimental models and in patients with primary and pseudoexfoliative open-angle glaucoma. CO2 laser was used to achieve deep scleral ablation. Percolation and perforation rates were recorded. Histopathological analysis was performed on laboratory models, complications were recorded and postoperative intraocular pressure (IOP) was measured. Results: Deep scleral ablation and aqueous percolation were repeatedly achieved. Histology disclosed deep scleral craters with a thin intact sclero-corneal tissue at the ablation area with mild, transient and limited thermal damage. Thirty of 37 patients with glaucoma completed 12 months of follow-up. The baseline IOP of 26.3 ± 7.8 mmHg (mean ± SD) dropped to 14.4 ± 3.4 mmHg and 14.3 ± 3.1 mmHg at six and 12 months, respectively (p<0.001). Complications were mild and transitory with no sequelae. Conclusions: CLASS using the IOPtiMate system is a safe and efficacious procedure for achieving effective fluid percolation.