Prevention of Ocular Tenon Adhesion to Sclera by a PDMAA Polymer to Improve Results after Glaucoma Surgery.

The authors describe a process that may eventually reduce the risk of scar formation after glaucoma surgery. For this, a thin hydrogel coating is photochemically generated and linked to the sclera surface at the surgical site. This coating is generated from a photoreactive prepolymer containing anthraquinone groups, which is administered as a thin pad to the sclera surface. Short UV irradiation leads to a reaction of the photogroups with neighboring chains via C-H insertion crosslinking, thus transforming the precursor polymer into a hydrogel. Simultaneously, a reaction between the photogroups and the underlying sclera tissue occurs, so that the hydrogel patch becomes covalently linked to the tissue. The authors show that the resulting thin coating is strongly cell repellent and hinders tenon fibroblasts to form tenon tissue at the site of the coating and is suitable for inclusion into a surgical procedure.

Long-term follow-up of intraocular pressure and pressure-lowering medication in patients after ab-interno trabeculectomy with the Trabectome.

BACKGROUND: The minimally invasive ab-interno trabeculectomy (AIT) via electro-ablation with the Trabectome has been on the European market since 2009. Many studies have proven the safety and efficacy of the procedure. Up until now, studies investigating the long-term effect of AIT have been sparse. In this study, we present long-term results of AIT in patients with primary and secondary open-angle glaucoma. METHODS: In a retrospective monocentric study, the data of all the patients having undergone the procedure in 2010 at our institution were recorded. Data was collected during routine examinations at our institution. In total, 81 eyes of 74 patients (46 patients with primary open-angle glaucoma (POAG), 28 patients with pseudoexfoliative glaucoma (PEXG)) were included. At every examination, the intraocular pressure (IOP) was measured using Goldmann applanation tonometry and the number of IOP-lowering medication was registered. Statistical analysis was done using the Kaplan-Meier analysis or Dunnett's t test, respectively. RESULTS: For both groups (POAG and PEXG), we found a significant lowering of the IOP (28% for POAG and 26% for PEXG) and a significant reduction of the number of IOP-lowering medication (32% for POAG and 29% for PEXG) after a median follow-up period of 3.5 years. CONCLUSION: In patients with open-angle glaucoma and especially pseudoexfoliative glaucoma, ab-interno trabeculectomy is an effective surgical procedure to significantly lower the intraocular pressure on a long-term basis.

Intraoperative optical coherence tomography and ab interno trabecular meshwork surgery with the Trabectome.

IMPORTANCE: This study is the first description of the use of the intraoperative optical coherence tomography (iOCT) for trabecular meshwork surgery with the Trabectome in a regular clinical setting. BACKGROUND: The aim of this study is to evaluate intraoperatively the immediate success of ab interno trabeculotomy with the Trabectome defined as a removal of the trabecular meshwork. DESIGN: This is a retrospective clinical study performed in the University Eye Hospital, Medical School Hannover. PARTICIPANTS: A total of nine consecutive Caucasian patients suffering from primary open angle glaucoma, pigment dispersion glaucoma, or pseudoexfoliation glaucoma took part in the study. METHODS: All patients underwent ab interno trabeculotomy surgery with the Trabectome using a commercially available iOCT to visualize the anterior chamber angle (ACA) before and after the procedure. The visualization was done using a modified Swan-Jacobs lens (all nine patients) or without lens (view from above, five patients). MAIN OUTCOME MEASURES: The main outcome of this study is the success of visualization of the ACA on iOCT, especially the postprocedural visualization of the wound gap after removal of the trabecular meshwork. RESULTS: Using the view from above, the ACA could be visualized before and after the procedure in only two of the five cases. Using the modified Swan-Jacobs lens, the ACA could be visualized before the procedure and the trabecular meshwork opening after the procedure in all nine patients. CONCLUSION: The iOCT can be used to objectify the immediate success of the surgical procedure, ie, the removal of the trabecular meshwork, of ab interno trabeculotomy with the Trabectome. The procedure itself cannot be captured sufficiently via iOCT.

Trabeculotomy opening size and IOP reduction after Trabectome® surgery.

BACKGROUND: Trabeculotomy with the Trabectome® is an effective surgical procedure to lower intraocular pressure (IOP). However, in some patients it does not lead to a significant IOP reduction despite a gonioscopically well visible opening of Schlemm's canal. This study investigated whether the size of the trabeculotomy opening and other parameters, including anterior chamber depth (ACD) are related to IOP reduction. METHODS: Retrospective observational case series with 93 eyes of 93 patients who underwent Trabectome surgery. Trabeculotomy opening and ACD were measured with an anterior segment swept source OCT. IOP was taken pre-operatively and at a single follow-up visit [follow-up time 125 ± 66 days (mean ± SD)]. The relationship between IOP reduction and OCT parameters and possible confounding factors was analyzed in a multiple linear regression model. RESULTS: The trabeculotomy opening size did not correlate with IOP reduction (slope of regression line = 0.0016; 95% confidence interval of slope: -0.025 to 0.028). The same applied for all other parameters tested, including ACD, which showed a tendency towards better IOP reduction with a deeper AC (slope = -1.9; 95% confidence interval: -5.54 to 1.73). Comparison between the 1st and 4th quartile of the trabeculotomy opening showed a significantly higher ACD in the largest trabeculotomy opening quartile (3.32 ± 0.05 mm vs. 3.16 ± 0.04 mm; p = 0.031). CONCLUSIONS: The fact that the trabeculotomy opening size did not correlate with IOP reduction points to the poorly understood role of the intrascleral aqueous outflow pathway in glaucomatous IOP elevation. A deeper AC might be a factor promoting a larger trabeculotomy opening.

Ab Interno Trabeculectomy With the Trabectome as a Valuable Therapeutic Option for Failed Filtering Blebs.

PURPOSE: Uncontrolled intraocular pressure (IOP) after glaucoma filtration surgery is a challenging problem in the management of glaucoma patients. The Trabectome is a device for selective electroablation of the trabecular meshwork through a clear cornea incision without affecting the conjunctiva. Minimally invasive glaucoma surgery using the Trabectome is safe and effective as primary glaucoma surgery. Here we investigate the results of ab interno trabeculectomy with the Trabectome for IOP control in patients with a failed filtering bleb. METHODS: A total of 60 eyes of 60 consecutive patients with primary open-angle glaucoma (POAG) or pseudoexfoliative glaucoma (PXG) were enrolled in this single center observational study. Trabectome surgery was performed alone or in combination with phacoemulsification by 2 experienced surgeons. IOP readings and number of IOP lowering medication as primary outcome parameters were taken by an independent examiner. Intraoperative and postoperative medication were recorded systematically. RESULTS: Mean IOP before surgery was 24.5±3.5 mm Hg and decreased to 15.7±3.4 (-36%) after mean follow-up of 415 days. The number of necessary IOP lowering medication dropped from 2.1±1.3 to 1.8±1.2 (14% reduction from baseline). A total of 25% (n=15) of cases reported here needed additional surgery after 517 days (range: 6 to 1563 d). No major complications were observed. After mean follow-up, we found a qualified success rate for PXG of 87% and 50% for POAG as revealed by the Kaplan-Meier analysis according to the definitions for success in advanced glaucoma cases according to the World Glaucoma Association (40% reduction from baseline IOP and maximum IOP of 15 mm Hg). DISCUSSION: Trabectome surgery for uncontrolled IOP after trabeculectomy is safe and effective especially in PXG patients. Given the demanding subgroup of patients studied here, it is not surprising that success rates are lower compared with previous studies investigating the Trabectome for primary glaucoma surgery. The number of necessary IOP lowering medication drops at first, but seems to reach preoperative values after 20 months of follow-up. Trabectome surgery should be considered as a valuable escape procedure for patients with failed filtering blebs and uncontrolled IOP.

Trabeculectomy ab interno with the Trabectome® as a therapeutic option for uveitic secondary glaucoma.

PURPOSE: Treatment of secondary glaucoma in uveitis patients is challenging. Owing to the young age of these patients, sufficient lowering of the intraocular pressure (IOP) is essential to prevent progression of visual field loss. However, because of the chronic inflammatory stimulus, filtration surgery has an increased risk of failure, especially in patients who have previously undergone surgery. Therefore, minimally invasive glaucoma surgery is a valuable alternative. METHODS: The clinical records of 24 consecutive patients with uveitic secondary glaucoma who underwent trabeculectomy ab interno with the Trabectome® at the Eye Center of the Albert-Ludwigs University of Freiburg between June 2009 and June 2014 (registered in the Freiburg trabectome database) were retrospectively analyzed. The general baseline information for each patient included age, gender, glaucoma type, ocular medication and current IOP. The postoperative IOP and number of antiglaucomatous medications were recorded at each visit. Statistical analyses were performed using the Kaplan-Meier estimator and Dunnett's t-test. RESULTS: The mean IOP before surgery was 31 ± 6.7 mmHg (median 32 mmHg). Both the IOP and the number of medications significantly decreased over the various follow-up intervals after trabeculectomy ab interno with the Trabectome®. Patients with follow-ups continuing past one year showed an IOP-reduction of approximately 40 % and a medication number reduction from 2 to 0.67. The failure rate (necessitating further glaucoma surgery) was N = 3 (12.5 %) patients. CONCLUSIONS: Trabeculectomy ab interno with the Trabectome® is a minimally invasive and effective method for controlling IOP in uveitic secondary glaucoma.

A new surgical triple procedure in pseudoexfoliation glaucoma using cataract surgery, Trabectome, and trabecular aspiration.

BACKGROUND: To evaluate the potential of lowering intraocular pressure in pseudoexfoliation glaucoma with combined phacoemulsification, Trabectome, and trabecular aspiration (triple procedure) compared to phacoemulsification and trabecular aspiration alone. METHODS: Using a case-matched retrospective study design, 30 patients were included into each group. The main outcome measures were the reduction of intraocular pressure and medication score at the end of follow-up. Clinical data were collected from the patients' medical records. RESULTS: Mean follow-up was 15 months in both groups. Intraocular pressure decreased from 25.3 ± 6.3 mmHg to 14.4 ± 3.7 mmHg (p < 0.0001) in the triple procedure group and from 25.3 ± 4.2 mmHg to 18.1 ± 4.2 mmHg (p < 0.0001) in the control group. The medication score was lowered from 3.4 ± 1.7 to 2.1 ± 1.2 (p = 0.0017) in the triple procedure group and from 3.8 ± 1.8 to 2.3 ± 1.5 (p < 0.008) in the control group. The reduction of intraocular pressure was higher (p < 0.004) in the triple procedure group (38.4 ± 17.3 %) compared to the control group (26.8 ± 19.6 %) The reduction of the medication score did not differ significantly. CONCLUSIONS: The triple procedure is more effective in lowering intraocular pressure compared to phacoemulsification and trabecular aspiration alone in pseudoexfoliation glaucoma.

The trabectome as treatment option in secondary glaucoma due to intraocular lymphoma.

Primary intraocular lymphoma can cause an elevation of intraocular pressure (IOP), resulting from infiltration of the trabecular meshwork with neoplastic lymphocytes. More rarely, therapeutic procedures can induce a highly synchronised death of tumor cells, leading to congestion of the trabecular meshwork with cell debris. We report on a case of severe IOP elevation after intraocular therapy with methotrexate and rituximab. As medical glaucoma therapy failed, a trabeculotomy with the trabectome was performed, leading to an immediate and sustained decrease in IOP. This novel approach is discussed considering pathogenic aspects of lymphoma-associated glaucoma and alternative surgical techniques.

Trabectome surgery for primary and secondary open angle glaucomas.

PURPOSE: In most forms of open angle glaucoma, the trabecular meshwork is the main barrier for aqueous humor outflow, causing elevated intraocular pressure (IOP). The Trabectome is a minimal invasive device for the surgical treatment of open angle glaucoma, particularly eliminating the juxtacanalicular meshwork. This study was conducted to compare the effectiveness and complication profile among different glaucoma subgroups. METHODS: Single center prospective observational study. There were 557 consecutive eyes of 487 patients included in this study. Trabectome surgery was performed either alone or in combination with cataract surgery. Intraoperative and postoperative complications were documented systematically. Main outcome measures were IOP reduction over time and the preoperative and postoperative number of IOP-lowering medications. Due to subgroup sizes, only data from eyes with primary open angle glaucoma and pseudoexfoliation glaucoma were processed for statistical analysis. RESULTS: For the 261 eyes classified as primary open angle glaucoma, preoperative IOP was 24 ± 5.5 mmHg (mean ± SD) under 2.1 ± 1.3 IOP-lowering medications. After a mean follow-up of 204 ± 238 days, IOP was reduced to 18 ± 6.1 mmHg, and medication was reduced to 1.2 ± 1.1. For the 173 eyes classified as pseudoexfoliation glaucoma, after a mean follow-up of 200 ± 278 days, IOP was reduced from 25 ± 5.9 mmHg to 18 ± 8.2 mmHg, and medication was reduced from 2.0 ± 1.2 to 1.1 ± 1.1. A Cox proportional hazards model hinted forward superiority of the combined surgery cases (Trabectome + Phaco + intraocular lens) in comparison to Trabectome surgery only in phakic or pseudophakic eyes. No serious complications were observed. CONCLUSIONS: Minimal invasive glaucoma surgery with the Trabectome seems to be safe and effective. The subgroup analysis of different kinds of open angle glaucomas presented in this study may help in first-line patient selection. The lack of ocular surface alterations makes it a valuable addition to glaucoma surgery.

Retrospective analysis of the success and safety of Gold Micro Shunt Implantation in glaucoma.

BACKGROUND: To evaluate the success rate and adverse effects of Gold Micro Shunt Plus (GMS+) implantation into the supraciliary space. METHODS: This retrospective study included 31 eyes of 31 patients diagnosed with severe glaucoma and uncontrolled intraocular pressure (IOP) with implantation of a GMS+ by means of a full-thickness scleral flap. The main outcome measures were surgical failure or success, based on the intraocular pressure and adverse effects. Clinical examination data are reported up to 4 years postoperatively. RESULTS: Thirty eyes (97%) met one of our criteria for failure. Within a mean of 7.3 ± 7.7 months another surgery was performed because of elevated IOP in 24 of 31 eyes (77%) and because of adverse effects in 2 (6%). The remaining 4 eyes, that met one of our criteria for failure, had an IOP reduction of less than 20% with comparable medication. Six GMS+'s were explanted; because of IOP elevation, 2; rubeosis iridis, 2; and low grade inflammation, 2. CONCLUSIONS: GMS+ implantation is not an effective method to control IOP in patients with glaucoma, when using our surgical technique. The reason for the found signs of chronic low grade inflammation or rubeosis iridis in 4 eyes (13%) remains unknown and has to be further investigated.

Comparative measurement of intraocular pressure by Icare tonometry and Airpuff tonometry in healthy subjects and patients wearing therapeutic soft contact lenses.

BACKGROUND: The aim of the present study was to compare the measurement of intraocular pressure (IOP) through a therapeutic soft contact lens with the "native" measurement. We additionally investigate whether a rebound tonometer (RT) or non-contact tonometer (NCT) is more suitable to measure IOP through a bandage contact lens. METHODS: The IOP was determined using each of the two methods, three times successively with (lens measurement) and without (native measurement) a soft contact lens. The Icare tonometer (Icare® TA01i, Icare Finland Oy, 23 subjects) and the Airpuff tonometer (Nidek NT 53OP, Nidek CO., LTD, Hiroishi Gamagori, Aichi, Japan, 16 subjects) were used. We compared the mean values (validity parameter) and standard deviation (precision parameter) of the three individual measurements in each case using the paired t-test. In addition, we conducted a power analysis to estimate the maximum error in the measurement caused by the contact lens (power level set to 0.8). RESULTS: With the Airpuff tonometer we detected no statistically significant between the lens and the native measurement (15.6 ± 2.6 vs. 15.3 ± 2.6 mmHg; p = 0.42). The power analysis revealed that the maximum error caused by the contact lens was 1.2 mmHg. The Icare tonometry, however, trended toward higher values in the contact lens measurements (17.5 ± 4.3 vs. 16.4 ± 3.5 mmHg in the native measurements; p = 0.05). Interestingly, this difference exhibited a statistically significant correlation with the corneal thickness (0.03 mmHg per µm corneal thickness; p = 0.04). CONCLUSION: The use of NCT and RT for IOP measurement over a soft contact lens is feasible. The accuracy appears to be sufficient for the most common clinical applications.

Quantification of retrograde axonal transport in the rat optic nerve by fluorogold spectrometry.

PURPOSE: Disturbed axonal transport is an important pathogenic factor in many neurodegenerative diseases, such as glaucoma, an eye disease characterised by progressive atrophy of the optic nerve. Quantification of retrograde axonal transport in the optic nerve usually requires labour intensive histochemical techniques or expensive equipment for in vivo imaging. Here, we report on a robust alternative method using Fluorogold (FG) as tracer, which is spectrometrically quantified in retinal tissue lysate. METHODS: To determine parameters reflecting the relative FG content of a sample FG was dissolved in retinal lysates at different concentrations and spectra were obtained. For validation in vivo FG was injected uni- or bilaterally into the superior colliculus (SC) of Sprague Dawley rats. The retinal lysate was analysed after 3, 5 and 7 days to determine the time course of FG accumulation in the retina (n = 15). In subsequent experiments axona transport was impaired by optic nerve crush (n = 3), laser-induced ocular hypertension (n = 5) or colchicine treatment to the SC (n = 10). RESULTS: Spectrometry at 370 nm excitation revealed two emission peaks at 430 and 610 nm. We devised a formula to calculate the relative FG content (c(FG)), from the emission spectrum. c(FG) is proportional to the real FG concentration as it corrects for variations of retinal protein concentration in the lysate. After SC injection, c(FG) monotonously increases with time (p = 0.002). Optic nerve axonal damage caused a significant decrease of c(FG) (crush p = 0.029; hypertension p = 0.025; colchicine p = 0.006). Lysates are amenable to subsequent protein analysis. CONCLUSIONS: Spectrometrical FG detection in retinal lysates allows for quantitative assessment of retrograde axonal transport using standard laboratory equipment. It is faster than histochemical techniques and may also complement morphological in vivo analyses.

Light scattering and wavefront aberrations in in vivo imaging of the rat eye: a comparison study.

PURPOSE: In vivo imaging of the retina is becoming an increasingly important research method. General anesthesia rapidly compromises the corneal surface, which increases scattering. In addition, wavefront aberrations limit the maximum imaging resolution. Three common methods of stabilizing the air-cornea interface and reducing scattering are the use of a contact lens, a microscopy slide coverslip, or mineral oil. These methods have not yet been analyzed regarding their impact on scattering and wavefront aberrations. METHODS: Nineteen eyes of 19 rats were analyzed with a custom-made Hartmann-Shack (HS) wavefront sensor. The amount of scattering was determined by analysis of the HS spot width, and the wavefront was reconstructed for the naked eye and each scattering-reducing method. Their effect on optical quality was determined by calculating the modulation transfer function (MTF). RESULTS: The three methods applied significantly reduced scattering but were differentially effective, with the coverslip performing the best and the mineral oil the worst. The root mean square (RMS) of the wavefront aberration, as well as the intereye variability of the RMS, was significantly smaller with the contact lens than with the coverslip. The MTF was best for the contact lens and worst for the coverslip, which was also illustrated by image simulations. CONCLUSIONS: The coverslip, contact lens, and mineral oil, when applied to the cornea, all reduced scattering. The best-performing method, the coverslip, increased wavefront aberrations. Overall, the contact lens had the best influence on image quality, and it appears to be the method of choice for high-resolution retinal imaging in rats.

The medical and surgical treatment of glaucoma.

BACKGROUND: Ongoing demographic changes in Europe are heightening the importance of adequate treatment for glaucoma, a disorder that is markedly more common in the elderly. METHOD: A selective search for relevant literature, including Cochrane Reviews and the guidelines of the European Glaucoma Society, regarding the topical and surgical treatment of glaucoma. RESULTS: It is recommended that the intraocular pressure (IOP) should be lowered by 20% to 50% from its baseline value, depending on the extent of already existing damage, the rate of progression, the baseline IOP, and the age of the patient. Topical monotherapy can lower the IOP by 15% to 30%. The success rate of filtration surgery has risen because of the intraoperative application of topical antimetabolites and currently ranges from 50% to 90%, depending on the study. CONCLUSIONS: The goal of glaucoma treatment is to protect the patient from blindness and visual impairment while keeping the treatment-related decline in quality of life to a minimum. Any type of glaucoma treatment, be it medical or surgical, must further this aim in consideration of the situation of the individual patient.

Self-application of single-use eyedrop containers in an elderly population: comparisons with standard eyedrop bottle and with younger patients.

PURPOSE: To test whether patients aged >or=80 years can safely and successfully apply eyedrops from a single-use eyedrop container without support, and to compare the results with those of younger patients using single-use containers and older patients using standard eyedrop bottles. METHODS: Patients aged >or=80 years who had no physical or mental conditions hindering self-application of eyedrops and actually did so because of glaucoma or dry eyes were included consecutively in the study group (n = 44) in order to perform self-application of eyedrops from single-use eyedrop containers. Patients were observed meticulously by two investigators, who documented practical problems during the procedure in a checklist. In control group A (n = 22), glaucoma or sicca patients aged between 50 and 65 years applied drops from single-use eyedrop containers; in control group B (n = 28), glaucoma or sicca patients aged >or=80 years used a traditional eyedrop bottle. RESULTS: Successful application of the drops into the conjunctival sac was achieved by 57% in the study group (95% and 89% in control groups A and B, respectively). Scratching of the eyedrop container along the conjunctiva or cornea was observed in 68% of the study group (41% and 61% in control groups A and B, respectively). Frequency of problems during opening and self-application of single-use eyedrop containers in the study group showed an inverse correlation to visual acuity in the better eye and previous experience with this kind of eyedrop container. CONCLUSION: Older patients have massive problems in self-administering eyedrops from single-use containers. Factors influencing the success of self-application may include the patient's previous experience with this kind of eyedrop container and the patient's visual acuity.

Cyclodialysis ab interno as a surgical approach to intractable glaucoma.

PURPOSE: In glaucoma filtration surgery, the problem of subconjunctival scarring has still not been satisfactorily solved. Suprachoroidal drainage of aqueous humour offers a promising, alternative option for intractable glaucoma. We here present a clinical study on the surgical approach of gonioscopic cyclodialysis ab interno. PATIENTS AND METHODS: Twenty-eight eyes of 20 patients with intractable glaucoma were included in this prospective, consecutive, case-control study. The eyes had had a mean of 4.4 +/- 2.4 previous antiglaucomatous interventions. Baseline intraocular pressure (IOP) was 34.3 +/- 10.5 mmHg despite maximum therapy. Under gonioscopic control, cyclodialysis ab interno was performed over two clock times to gain access to the suprachoroidal space. No additional trabecular meshwork surgery was performed. Success was defined as a lowering of IOP to below 21 mmHg without the need for further medication or intervention. RESULTS: Mean postoperative IOP was 14.6 +/- 12.4 mmHg. Mean follow-up (FU) for all eyes was 121.8 days. After a mean of 60 days, 21 eyes (75%) needed further surgical intervention. Qualified success was seen in four eyes (14.3%), with a mean FU of 383.6 days. Three eyes (10.7%) showed absolute success after a mean FU period of 202.7 days. In our series, we obtained the best results for phakic eyes, followed by pseudophakic and aphakic eyes. CONCLUSION: The results of this study do not provide convincing evidence of the functional efficacy of cyclodialysis ab interno. Nevertheless, the technique is easy to perform and offers safe and atraumatic access to the resorptive capability of the choroid. Conjunctival manipulation is avoided. Contrary to reports in the current literature, in our series, the best results were obtained for phakic eyes, though the small number of eyes included does not allow reliable statistics. Further studies will need to focus on the use of different space-retaining substances or a widening of the cyclodialysis cleft to improve surgical outcome.

A novel approach to suprachoroidal drainage for the surgical treatment of intractable glaucoma.

PURPOSE: In glaucoma surgery, scarring of the artificial fistula is the limiting factor for long-term control of intraocular pressure (IOP). Several devices and surgical techniques have been developed for artificial aqueous humor drainage in intractable glaucoma. The authors describe a novel surgical technique that uses a silicone tube as a shunt for aqueous flow from the anterior chamber to the suprachoroidal space. PATIENTS AND METHODS: Thirty-one eyes of 31 patients with uncontrollable refractory glaucoma were included in this prospective consecutive case-control study. Each eye had undergone an average of 3.5+/-1.9 previous interventions for glaucoma. The baseline IOP was 44.25+/-8.7 mm Hg despite maximum therapy. As in trabeculectomy, a limbus-based scleral flap was prepared. The suprachoroidal space was accessed via a deep posterior scleral flap. The silicone tube was inserted as an intrascleral connection from the anterior chamber to the suprachoroidal space. Cyclodialysis was avoided by this surgical approach. Success was defined as a lowering of IOP to below 21 mm Hg without the need for further medication or intervention. RESULTS: The mean functional shunt survival was 55.9+/-45.6 weeks. IOP was reduced to 12.9+/-5.2 mm Hg in 70% of all eyes after 30 weeks postoperatively. After 52 weeks, 60% of the eyes could be classified as representing success, and 76 weeks after surgery, 40% of the eyes still showed controlled IOP. In none of the eyes were severe postoperative hypotony or suprachoroidal bleeding observed. No localized or general inflammation or infection was seen in connection with the silicon tube. Two patients needed anterior chamber lavage because of bleeding. In 2 patients the tube had to be removed because of corneal endothelial contact. Shunt failure of the tube was caused in some cases by connective tissue formation at the posterior lumen of the tube. CONCLUSION: This novel surgical approach and the placement of the silicone tube described here have several advantages. Its intrascleral course minimizes the risk of conjunctival erosion and associated infections. No cyclodialysis is performed. Connection to the suprachoroidal space exploits the resorptive capability of the choroid. It guarantees drainage but also provides a natural counterpressure, avoiding severe postoperative hypotony. The suprachoroidal shunt presented here achieves good follow-up results in terms of IOP control. No serious complications have been observed. This new method promises to be an effective surgical technique and presents a new therapeutic option in intractable glaucoma. Fibroblast reaction obstructing the posterior lumen, seemed to be the only factor limiting drainage. Further studies and experiments will be needed to elucidate the exact physiologic mechanisms underlying the draining, the capacity and duration of the draining effect, and the histologic background of suprachoroidal scarring.