Manfred Tetz

Canaloplasty: Circumferential viscodilation and tensioning of Schlemm canal using a flexible microcatheter for the treatment of open-angle glaucoma in adults : Two-year interim clinical study results

PURPOSE: To evaluate the safety and efficacy of circumferential viscodilation and tensioning of the inner wall of Schlemms canal in a new surgical procedure for the treatment of open‐angle glaucoma (OAG). SETTING: Fourteen clinical sites in the United States and Germany. METHODS: In this international multicenter prospective study of adult patients with OAG having glaucoma surgery, patients with qualifying preoperative intraocular pressure (IOP) of at least 16 mm Hg or higher and open angles were eligible. Evaluation was performed at baseline and 1 day, 1 week, and 1, 3, 6, and 12 months preoperatively. After a nonpenetrating dissection technique to expose Schlemms canal was performed, a flexible microcatheter (iTrack 250A, iScience Interventional) was used to dilate the full circumference of the canal by injecting sodium hyaluronate 1.4% (Healon GV) during catheterization. A suture loop was placed in the canal to apply tension to the trabecular meshwork. High‐resolution ultrasound imaging was used to assess Schlemms canal and anterior segment angle morphology, including distension of the trabecular meshwork caused by the tensioning suture. Data analysis was performed in 2 groups: Group 1, in which patients met all inclusion criteria, and Group 2, made up of Group 1 patients who had successful suture placement. RESULTS: Group 1 comprised 94 patients and Group 2, 74 patients. The mean baseline IOP in Group 1 was 24.7 mm Hg ± 4.8 (SD) on a mean of 1.9 ± 1.0 medications per patient. In Group 2 (patients with sutures), the mean IOP was 16.1 ± 4.7 mm Hg 3 months postoperatively, 15.6 ± 4.0 mm Hg at 6 months, and 15.3 ± 3.8 mm Hg at 1 year. Medication use dropped to a mean of 0.6 ± 0.9 per patient at 12 months. Suture tensioning was an apparent contributing factor in achieving surgical success. Patients with measurable trabecular meshwork distension from suture tension had a mean IOP of 15.9 ± 5.2 mm Hg at 6 months and 14.5 ± 3.0 mm Hg at 12 months. Surgical and postsurgical adverse events were reported in 15 of 94 patients (16%) and included hyphema (3), elevated IOP greater than 30 mm Hg (3), Descemets tear (1), hypotony (1), choroidal effusion (1), and exposed closure suture with eyelid edema and erythema epiphora (1); 4 patients were subsequently converted to trabeculectomy. CONCLUSION: Circumferential viscodilation and tensioning of Schlemms canal was a safe and effective surgical procedure to reduce IOP in adult patients with OAG.

Anterior chamber lenses. Part I: Complications and pathology and a review of designs

ABSTRACT Clinicopathologic data to assist ophthalmologists in choosing a safe and efficacious anterior chamber intraocular lens (IOL) are rapidly becoming available. Two important factors that have led to an increased success rate with some anterior chamber IOL styles are (1) attention to lens design and (2) attention to modern manufacturing and lens finishing techniques. We now know much more about how to achieve appropriate lens flexibility, which decreases the need for perfect sizing. Increased attention has been given to the anteriorposterior vaulting characteristics of IOLs. This has reduced the incidence of various complications such as the intermittent touch syndrome and the uveal chafing syndrome. We recognize several design flaws in some lens styles. For example, there is now a considerable decrease in the number of small‐diameter, roundlooped anterior chamber IOLs being implanted, particularly those with a closed‐loop configuration. Several problems have been and continue to be caused by some poorly manufactured anterior chamber lenses with sharp optic and haptic edges. Technology to assure smooth lens finishing and polishing is available and readily accessible to all manufacturers. Defective lenses should soon be a thing of the past.

Decentration of Flexible Loop Posterior Chamber Intraocular Lenses in a Series of 222 Postmortem Eyes

Two hundred twenty-two postmortem eyes containing posterior chamber intraocular lenses (IOLs) were analyzed for optic decentration in relationship to lens style, implant duration, and loop fixation site. Decentration values were not affected significantly by either lens style or implant duration. In 33.3% of specimens, both loops were situated within the lens capsular sac, 18.0% had both loops fixated in the ciliary sulcus, and in 48.7% one loop was fixated in the lens capsular sac and the opposite loop in the ciliary sulcus or zonular region. There was a statistically significant difference in the amount of decentration in the three fixation groups studied. Capsular fixation provides the best and most consistent centration compared with fixation of both loops in the ciliary sulcus or asymmetrical fixation with only one loop in the capsular sac.

Posterior capsular opacification and intraocular lens decentration Part I: Comparison of various posterior chamber lens designs implanted in the rabbit model

ABSTRACT Experimental phacoemulsification procedures were performed in 54 Rex rabbits. In 96 eyes, posterior chamber intraocular lenses (IOLs) were implanted in the capsular sac, and 12 eyes served as controls with no lens implantation. The IOLs were divided into eight groups consisting of both one‐piece and three‐piece styles with various optic designs. Each lens was evaluated for the relative effect on posterior capsular opacification (PCO) and optic decentration, two of the most common complications of modern cataract surgery and IOL implantation. Optics with a convex‐anterior, plano‐posterior design (the type of IOL optic most frequently implanted today) had the highest incidence of PCO With capsular fixated IOLs, the features that have a statistically significant impact on reducing PCO include (1) one‐piece, all‐polymethylmethacrylate (PMMA) IOL styles, (2) a biconvex or posterior convex optic design, and (3) angulated loops. Lens decentration was not affected by the optic design, but statistical analysis showed that one‐piece, all‐PMMA IOL construction provided the most consistent centration.

Posterior capsular opacification and intraocular lens decentration Part II: Experimental findings on a prototype circular intraocular lens design

ABSTRACT In a prospective randomized study, 25 New Zealand white rabbit eyes were implanted with four intraocular lens (IOL) designs These included a one‐piece modified J‐loop IOL, a three‐piece modified J‐loop IOL, a rigid disc IOL, and an experimental compressible disc (CD) IOL. The CD IOL revealed the lowest mean posterior capsular opacification (PCO) of all IOLs tested (P <.01). With all lenses tested, a positive correlation between PCO and decentration was found (R = 0.55, P <.05). These results suggest that because of its design features (i.e., one‐piece construction, biconvex optic, posterior angulation of the fixation element), the CD lens produces a mechanical barrier against lens epithelial cell migration and reduces the incidence of PCO.

Canaloplasty: Circumferential viscodilation and tensioning of Schlemm canal using a flexible microcatheter for the treatment of open-angle glaucoma in adults

PURPOSE: To evaluate 2‐year postsurgical safety and efficacy of canaloplasty (circumferential viscodilation and tensioning of the inner wall of Schlemm canal) to treat open‐angle glaucoma (OAG). SETTING: Multicenter surgical sites. METHODS: This international prospective study comprised adult OAG patients having glaucoma surgery or combined glaucoma–cataract surgery. Qualifying preoperative intraocular pressure (IOP) was at least 16 mm Hg and historical IOP, at least 21 mm Hg. The full circumference of the canal was viscodilated and a trabecular tensioning suture placed with a microcatheter. Primary outcome measures included IOP and glaucoma medication use. RESULTS: At 24 months, all 127 eyes (127 patients) had a mean IOP of 16.0 mm Hg ± 4.2 (SD) and mean glaucoma medication use of 0.5 ± 0.8 (baseline values 23.6 ± 4.8 mm Hg and 1.9 ± 0.8 medications). Eyes with canaloplasty alone had a mean IOP of 16.3 ± 3.7 mm Hg and 0.6 ± 0.8 medications (baseline values 23.2 ± 4.0 mm Hg and 2.0 ± 0.8 medications). Eyes with combined glaucoma–cataract surgery had a mean IOP of 13.4 ± 4.0 mm Hg and 0.2 ± 0.4 medications (baseline values 23.1 ± 5.5 mm Hg and 1.7 ± 1.0 medications). The IOP and medication use results at all time points were statistically significant versus baseline (P <.001). The late postoperative follow‐up identified 3 patients with elevated IOP. No other serious ocular or nonocular complications were reported. CONCLUSION: Canaloplasty was safe and effective in reducing IOP in adult patients with OAG.

Canaloplasty: Three-year results of circumferential viscodilation and tensioning of Schlemm canal using a microcatheter to treat open-angle glaucoma

PURPOSE: To report 3‐year results of the safety and efficacy of canaloplasty, a procedure involving circumferential viscodilation and tensioning of the inner wall of Schlemm canal to treat open‐angle glaucoma. SETTING: Multicenter surgical sites. DESIGN: Nonrandomized multicenter clinical trial. METHODS: This study comprised adult open‐angle glaucoma patients having canaloplasty or combined cataract–canaloplasty surgery. Qualifying preoperative intraocular pressures (IOPs) were at least 16 mm Hg with historical IOPs of at least 21 mm Hg. A flexible microcatheter was used to viscodilate the full circumference of the canal and to place a trabecular tensioning suture. Primary outcome measures included IOP, glaucoma medication use, and adverse events. RESULTS: Three years postoperatively, all study eyes (n = 157) had a mean IOP of 15.2 mm Hg ± 3.5 (SD) and mean glaucoma medication use of 0.8 ± 0.9 compared with a baseline IOP of 23.8 ± 5.0 mm Hg on 1.8 ± 0.9 medications. Eyes with combined cataract–canaloplasty surgery had a mean IOP of 13.6 ± 3.6 mm Hg on 0.3 ± 0.5 medications compared with a baseline IOP of 23.5 ± 5.2 mm Hg on 1.5 ± 1.0 medications. Intraocular pressure and medication use results in all eyes were significantly decreased from baseline at every time point (P<.001). Late postoperative complications included cataract (12.7%), transient IOP elevation (6.4%), and partial suture extrusion through the trabecular meshwork (0.6%). CONCLUSION: Canaloplasty led to a significant and sustained IOP reduction in adult patients with open‐angle glaucoma and had an excellent short‐ and long‐term postoperative safety profile. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned. Additional disclosures are found in the footnotes.

Localized endophthalmitis: A newly described cause of the so-called toxic lens syndrome

ABSTRACT We report five cases of post‐extracapsular cataract extraction infection in which subsequent pathologic analyses identified the organisms and found the infection to be localized or confined to the lens capsular sac. The most common offending organisms were gram‐positive pleomorphic bacilli. In one case, we were able to identify the bacteria as Propionibacterium acnes. We designate this condition a localized endophthalmitis. It should be considered any time a persistent, smoldering, postoperative inflammation occurs, and in the differential diagnosis of phacoanaphylactic endophthalmitis. The condition itself is not new, but undoubtedly many such cases have gone unrecognized or have been misdiagnosed as the so‐called toxic lens syndrome. In localized endophthalmitis, a clinically visible inflammatory process may occur even when multiple diagnostic taps are negative, although when the cases first appeared, the surgeons were not aware of the entity and anaerobic cultures were not always obtained. A negative tap may be explained by the fact that metabolic products from the organisms are released from the bag into the anterior segment and vitreous. A synergistic reaction may occur between these organisms and retained lens cortical remnants that may cause or exacerbate a hypersensitivity reaction. The condition may be worsened by Nd:YAG capsulotomy. The pathogenesis of localized endophthalmitis has nothing to do with the type of intraocular lens fixation (lens capsular sac or ciliary sulcus); rather, the simple presence of a capsular sac after extracapsular cataract extraction is the prerequisite for the clinical condition.

Anterior chamber lenses. Part II: A laboratory study

ABSTRACT An analysis of 606 surgically removed anterior chamber intraocular lens (IOL) specimens revealed that 351 or 58% of these were smalldiameter, round loop, closed‐loop styles. Because of the extremely high percentage of IOLs with this design received in our laboratory and the correlation of clinical histories with our histopathologic findings, we have concluded that such IOLs do not provide the safety and efficacy achieved by other anterior chamber lens designs. The finely polished, one‐piece, all‐PMMA styles fared well in our study. Although these one‐piece styles comprise well over 50% of the American market share of anterior chamber IOLs, they comprise only 14% of all anterior chamber IOLs accessioned in our laboratory, compared to 58% for closed‐loop designs. We believe that implantation of anterior chamber lenses with small‐diameter, round, closed loops is no longer warranted. Patients in whom these IOLs have already been implanted should be carefully followed. It is our opinion that the FDA should recall or closely monitor all IOLs of this design and that implantation of closed‐loop lenses should be discontinued in the United States. Furthermore, we believe that an IOL deemed to be not medically sound or worthy of implantation in the United States should not be marketed or donated outside of this country.

Complications of Intraocular Lenses with Special Reference to an Analysis of 2500 Explanted Intraocular Lenses (IOLs)

Abstract The incidence and types of complications seen with the major intraocular lens (IOL) types in a series of 2500 explant cases is reported. We confirm that the rate of complications is higher with anterior chamber IOLs (AC-IOLs) and with iris-fixated IOLs (IF-IOLs) than with posterior chamber IOLs (PC-IOLs). However, the open-loop AC-IOL fared better than the closed-loop designs. Although tissue complications of PC-IOLs (inflammation, glaucoma, cystoid macular oedema and retinal detachment) have decreased markedly, this study shows that decentration/ malposition remains a significant problem. With increased use of smaller diameter or aspherical optic (5.5 mm × 5.5 mm or 5 mm × 6 mm), as well as increasing use of bifocal/multifocal IOLs, it is important that the problem of decentration be addressed.