Matthias C. Grieshaber

Canaloplasty for primary open-angle glaucoma: long-term outcome

Background/Aims To study the safety and effectiveness of 360° viscodilation and tensioning of Schlemm canal (canaloplasty) in black African patients with primary open-angle glaucoma (POAG). Methods Sixty randomly selected eyes of 60 consecutive patients with POAG were included in this prospective study. Canaloplasty comprised 360° catheterisation of Schlemms canal by means of a flexible microcatheter with distension of the canal by a tensioning 10-0 polypropylene suture. Results The mean preoperative intraocular pressure pressure (IOP) was 45.0±12.1 mm Hg. The mean follow-up time was 30.6±8.4 months. The mean IOP at 12 months was 15.4±5.2 mm Hg (n=54), at 24 months 16.3±4.2 mm Hg (n=51) and at 36 months 13.3±1.7 mm Hg (n=49). For IOP ≤21 mm Hg, complete success rate was 77.5% and qualified success rate was 81.6% at 36 months. Cox regression analysis showed that preoperative IOP (HR=1.003, 95% CI=0.927 to 1.085; p=0.94), age (HR=1.000, CI=0.938 to 1.067; p=0.98) and sex (HR=3.005, CI=0.329 to 27.448; p=0.33) were all not significant predictors of IOP reduction to ≤21 mm Hg. Complication rate was low (Descemets detachment n=2, elevated IOP n=1, false passage of the catheter n=2). Conclusion Canaloplasty produced a sustained long-term reduction of IOP in black Africans with POAG independent of preoperative IOP. As a bleb-independent procedure, canaloplasty may be a true alternative to classic filtering surgery, in particular in patients with enhanced wound healing and scar formation.

The potential value of natural antioxidative treatment in glaucoma

Glaucomatous optic neuropathy implies loss of retinal ganglion cells, including their axons, and a major tissue remodeling, especially in the optic nerve head. Although increased intraocular pressure is a major risk factor for glaucomatous optic neuropathy, there is little doubt that other factors such as ocular blood flow play a role as well. Mechanisms leading to glaucomatous optic neuropathy are not yet clearly understood. There is, however, increasing evidence that both an activation of glial cells and an oxidative stress in the axons play an important role. Glial cells may be activated by mechanical stress via activation of the epidermal growth-factor-receptor, or by ischemic stress via an increase in endothelin. Several factors can systemically or locally increase oxidative stress. In glaucoma, an unstable ocular blood flow leading to repeated mild reperfusion seems to be most relevant in inducing oxidative stress. The simultaneous production of nitric oxide in the astrocytes and of superoxide in the mitochondria of the axons leads to the production of the damaging peroxynitrite. Therapeutically, we need to reduce intraocular pressure, stabilize ocular blood flow, and reduce oxidative stress. Various natural compounds possess potential antioxidative value. Reduction of oxidative stress at the level of mitochondria can be achieved by gingko biloba. Polyphenolic compounds, such as tea, red wine, dark chocolate, or coffee have antioxidative properties. Coffee contains 3-methyl-1,2-cyclopentanedione (MCP), capable of scavenging peroxynitirite. Red wine-polyphenols (e.g., resveratrol), exert vasoprotective effects by inhibiting the synthesis of endothelin-1. Dark chocolate decreases blood pressure and improves endothelium-dependant vasorelaxation. Anthocyanosides (bilberries) owe their antioxidant effects to their particular chemical structure. Other antioxidants include ubiquinone and melatonin.

Circumferential viscocanalostomy and suture canal distension (canaloplasty) for whites with open-angle glaucoma.

PurposeTo assess the safety and efficacy of canaloplasty (360-degree viscodilation and tensioning of the Schlemm canal) in Whites with open-angle glaucoma (OAG). MethodsIn a prospective study, 32 consecutive patients with medically uncontrolled OAG underwent primary canaloplasty with a follow-up time of more than 1 year. Laser goniopuncture was performed if postoperative intraocular pressure (IOP) was above 16 mmHg. IOP, number of antiglaucomatous medications, best-corrected visual acuity, and intraoperative and postoperative complications were recorded. Complete success was defined as an IOP ⩽21, 18, and 16 mm Hg without medications, and qualified success with or without medications, respectively. ResultsThe mean IOP dropped from 27.3±5.6 mm Hg preoperatively to 12.8±1.5 mm Hg at 12 months and 13.1±1.2 mm Hg at 18 months (P<0.001). The complete success rate of an IOP ⩽21, 18, and 16 mm Hg was 93.8% [95% confidence interval (CI) 0.86-1.0], 84.4% (95% CI 0.73-0.98), and 74.9% (95% CI 0.61-0.92), respectively, at 12 months. Laser goniopuncture was performed on 6 eyes (18.1%) 3.3±2.1 months postoperatively. The mean IOP was 20.6±4.2 mm Hg before and 14.2±2.2 mm Hg after goniopuncture. The number of medications dropped from 2.7±0.5 before surgery to 0.1±0.3 after surgery (P<0.001). The postoperative best-corrected visual acuity at last visit (0.38±0.45; range: 0 to 1.8) was comparable with that of preoperative values (0.36±SD 0.37; range: 0 to 1.6) (P=0.42). In all but 1 eye, canaloplasty was completed. Minor intraoperative or postoperative complications like Descemet membrane detachment in 2 eyes, elevated IOP in 1 eye, and suprachoroidal passage of the catheter in 4 eyes were encountered. In 1 eye, circumferential cannulation of the Schlemm canal was impossible. ConclusionsCanaloplasty seems to be a promising and effective surgical procedure in Whites with OAG. Postoperative IOP levels are in the low-to-mid-teens. The procedure can be regarded as safe, but has its own profile of complications.

Relationship between retinal glial cell activation in glaucoma and vascular dysregulation.

PurposeTo investigate the possible relationship between presumed activated retinal astrocytes and Müller cells (ARAM) and primary vascular dysregulation (PVD) in patients with primary open-angle glaucoma (POAG). Patients and MethodsOne hundred eighty-six eyes of 93 patients with POAG were included in the study. Presumed ARAM was defined as patchy, discrete glittering but transparent changes of the retina. The diagnosis of PVD was based on both the patients history and an abnormal circulatory behavior. Frequency tables were used to describe categorical variables, and differences were compared by means of χ2 test. A generalized linear mixed model was applied to determine the influence of vascular dysregulation, mean visual defect, and age on ARAM. ResultsARAM was found to be bilateral in 26.8% of patients (50 eyes), and unilateral in 11.8% (11 eyes). Patients mean age was 68.6 (SD±8.1) years in the group with ARAM and 65.6 (SD±13.6) years in the group without (P=0.56). In the generalized linear mixed model, ARAM was significantly associated with vascular dysregulation [odds ratios (OR): 4.4, confidence intervals (CI): 1.7-11.3, P=0.002] but not with greater age (OR: 1.1 per decade of years, 0.7-1.6, P=0.48) and eye side (OR: 1.1, CI: 0.8-1.6, P=0.52). An increase of mean visual defect of 5.5 dB doubled the risk for ARAM (OR: 2.0; CI: 1.5-2.7, P<0.001). ConclusionsPresumed retinal glial cell activation in POAG is clearly related to vascular dysregulation and to some extent to the stage of glaucomatous damage.

Novel device for expanding Schlemm's canal: a morphological study: Implantation of the Stegmann Canal Expander following viscodilation of Schlemm's canal resulted in permanent expansion of the canal lumen and distension of the trabecular meshwork without complications

This study was performed to assess any changes in Schlemms canal (SC) in human autopsy eyes possibly resulting from the injection of a viscoelastic substance and implantation of a new device (the Stegmann Canal Expander, SCE) into SC. After the surgical procedure, eyes were fixed, dissected into quartered segments and examined using light and scanning electron microscopy. Tissue sections displayed a marked dilation of SC and of the collector channels compared with untreated control sections. The SC walls were disrupted in some areas due to viscodilation, but not due to SCE implantation. In all eyes, the entire 9-mm length of the SCE was positioned inside the canal, keeping the canal wide open. The SCE diameter of 240 μm remained unchanged after implantation. Injection of a viscoelastic substance into SC leads to marked dilation of SC and collector channels. Implanting the SCE into SC allowed persistent expansion of SC and stretching of the trabecular meshwork. This may increase the permeability of the trabecular meshwork, reduce its resistance to aqueous humour and maintain circumferential flow within SC. Experimental and clinical studies should determine the impact of this new canal expander in terms of lowering intraocular pressure in glaucoma surgery.

Novel device for expanding Schlemm9s canal: a morphological study

This study was performed to assess any changes in Schlemms canal (SC) in human autopsy eyes possibly resulting from the injection of a viscoelastic substance and implantation of a new device (the Stegmann Canal Expander, SCE) into SC. After the surgical procedure, eyes were fixed, dissected into quartered segments and examined using light and scanning electron microscopy. Tissue sections displayed a marked dilation of SC and of the collector channels compared with untreated control sections. The SC walls were disrupted in some areas due to viscodilation, but not due to SCE implantation. In all eyes, the entire 9-mm length of the SCE was positioned inside the canal, keeping the canal wide open. The SCE diameter of 240 μm remained unchanged after implantation. Injection of a viscoelastic substance into SC leads to marked dilation of SC and collector channels. Implanting the SCE into SC allowed persistent expansion of SC and stretching of the trabecular meshwork. This may increase the permeability of the trabecular meshwork, reduce its resistance to aqueous humour and maintain circumferential flow within SC. Experimental and clinical studies should determine the impact of this new canal expander in terms of lowering intraocular pressure in glaucoma surgery.

Canaloplasty with Stegmann Canal Expander for primary open-angle glaucoma: two-year clinical results

To examine longer‐term postsurgical safety and efficacy of a new expander for Schlemms canal.

A New Expander for Schlemm Canal Surgery in Primary Open-angle Glaucoma-Interim Clinical Results.

Purpose:To evaluate a new canal expander in circumferential viscocanalostomy (canaloplasty) for whites with primary open-angle glaucoma (POAG). Design:Prospective, single-center, noncomparative study. Participants:Twenty-two eyes of 22 consecutive patients with medically uncontrolled POAG underwent primary viscocanalostomy and implantation of the Stegmann Canal Expander into Schlemm canal with a follow-up time of at least 1 year. Materials and Methods:Schlemm canal was unroofed ab externo, and dilated with viscoelastic material and microcatheter. The Stegmann Canal Expander is a flexible, fenestrated hollow implant of 9 mm in length. One expander was implanted into either side of the surgically created of ostium to keep the Schlemm canal permanently open. The superficial scleral flap was closed watertight. Laser goniopuncture of the trabeculo-Descemet membrane window was performed if postoperative intraocular pressure (IOP) exceeded 16 mm Hg. Main Outcome Measures:Complete successes were defined as a confirmed IOP⩽21, ⩽18, and ⩽16 mm Hg without medications, respectively, combined with a 30% IOP reduction. Number of antiglaucomatous medications, best-corrected visual acuity, and intraoperative and postoperative complications were recorded. Results:The mean IOP dropped from 27.1±5.3 mm Hg preoperatively to 13.6±1.6 mm Hg at 6 months, 13.0±1.5 mm Hg at 9 months, and 13.1±2.2 mm Hg at 12 months (P<0.001). The complete success rates for an IOP⩽21, ⩽18, and ⩽16 mm Hg combined with a 30% IOP reduction were 91% [95% confidence interval (CI), 0.80-1.0], 91% (95% CI, 0.80-1.0), and 91.0% (95% CI, 0.80-1.0) at 6 months, and 86% (95% CI, 0.73-1.0), 82% (95% CI, 0.67-1.0), and 82.0% (95% CI, 0.67-1.0) at 12 months. The success rate of an IOP⩽16 mm Hg without medications did not depend on age [hazard ratios (HR) 1.02; 95% CI, 0.85-1.12; P=0.74], preoperative IOP (HR 0.97; 95% CI, 0.83-1.23; P=0.89), and mean visual defect (HR 1.05; 95% CI, 0.72-1.27; P=0.76). Laser goniopuncture was performed on 2 eyes (9%) 4.1 months postoperatively; the mean IOP was 19.5 mm Hg before and 13.6 mm Hg after goniopuncture. The number of medications dropped from 2.9±0.6 before surgery to 0.05±0.2 after surgery (P<0.001). The postoperative best-corrected visual acuity at last visit (0.12±0.09; range, 0 to 0.39) was comparable to preoperative values (mean±SD, 0.16±0.10; range, 0 to 0.39) (P=0.35). Minor intraoperative or postoperative complications included microhyphema (8 eyes) and transient elevated IOP (steroid responder; 2 eyes). Conclusions:Implantation of the Stegmann Canal Expander in canaloplasty lowered IOP significantly in POAG without complications related to the device in this 1-year observation period.

Ciliary Body Clefting Accompanied by Rupture of the Trabecular Meshwork in Congenital Glaucoma

1. Sadun AA, Carelli V, Salomao SR, et al. Extensive investigation of a large Brazilian pedigree of 11778/haplogroup J Leber hereditary optic neuropathy. Am J Ophthalmol. 2003;136(2):231-238. 2. Seo JH, Hwang JM, Park SS. Comparison of retinal nerve fibre layers between 11778 and 14484 mutations in Leber’s hereditary optic neuropathy. Eye (Lond). 2010;24(1):107-111. 3. Newman NJ, Biousse V, Newman SA, et al. Progression of visual field defects in Leber hereditary optic neuropathy: experience of the LHON Treatment Trial. Am J Ophthalmol. 2006;141(6):1061-1067.

A journey through selected aspects of glaucoma: Glaucoma Meeting Basel, 2006

The Glaucoma Meeting Basel is held on an annual basis and creates a unique occasion to introduce and discuss various fundamental aspects in glaucoma. This year, the meeting was held on October 12–13 and was organized primarily by Matthias Grieshaber, a senior physician at the University Eye Clinic, Basel, Switzerland. More than 300 participants from all over Europe, North America and Asia attended the meeting and were all welcomed by Josef Flammer, head of the University Eye Clinic, Basel, Switzerland. All speakers were introduced briefly, prior to their presentation, by either Selim Orgül, head of the diagnostics department at the University Eye Clinic, Basel, or by Matthias Grieshaber. The meeting provided an overview of fundamental aspects in glaucoma and was divided into seven different topicoriented sessions; namely, intraocular pressure, optic nerve head changes in glaucoma, clinical imaging of the eye, visual function in glaucoma, ocular blood flow, systemic factors in glaucoma and reperfusion damage and therapy. This is a short review of selected aspects introduced at this meeting.