Günter K. Krieglstein

Primary phacoemulsification and intraocular lens implantation for acute angle-closure Glaucoma

OBJECTIVE To evaluate the safety and efficacy of primary phacoemulsification and intraocular lens implantation (PPI) for acute angle-closure glaucoma (ACG). STUDY DESIGN Prospective, nonrandomized comparative trial. PARTICIPANTS AND INTERVENTION Forty-three eyes of 43 patients with acute ACG and uncontrolled intraocular pressure (IOP) were treated by PPI. Thirty-two eyes of 32 patients treated by conventional surgical iridectomy (CSI) constituted the control group. MAIN OUTCOME MEASURES Postoperative visual acuity, IOP, number of antiglaucoma medications, complications, and secondary surgical interventions, if any, required for IOP control. RESULTS Glaucoma control was achieved in 31 eyes (72%) in the PPI group and in 11 (35%) in the CSI group (P = 0.01). Mean preoperative IOP was 40.5 +/- 7.6 mmHg (standard deviation) and 39.7 +/- 7.8 mmHg, respectively (P = 0.46). Mean postoperative IOP was 17.8 +/- 3.4 mmHg (PPI group) and 20.1 +/- 4.2 mmHg (CSI group) after a mean follow-up of 10.2 +/- 3.4 months (P = 0.03). Postoperatively, the mean number of ocular hypotensive medications was 0.18 +/- 0.45 (PPI group) and 0.45 +/- 0.62 (CSI group) (P = 0.0001). Relative increase in postoperative best-corrected visual acuity (logarithm of the minimum angle of resolution) was 0.52 +/- 0.29 (PPI group) and 0.19 +/- 0.21 (CSI group), respectively (P = 0.0001). Additional surgery was necessary in 5 eyes (11.5%) in the PPI group and in 20 eyes (63%) in the CSI group (P = 0.01). Intraoperative and postoperative complications were few and manageable. CONCLUSIONS CSI in patients with acute ACG was effective in reducing IOP initially but was associated with multiple surgical reinterventions. Conversely, primary PPI turned out to be safe and effective in reducing IOP and improving visual acuity. These results affirm that lens extraction may be considered the better procedure in uncontrolled ACG when faced with options of CSI or PPI.

Primary viscocanalostomy versus trabeculectomy in white patients with open-angle glaucoma: A randomized clinical trial

PURPOSE To compare viscocanalostomy, a nonpenetrating procedure for glaucoma treatment, with trabeculectomy. DESIGN Randomized controlled trial. PARTICIPANTS Twenty white subjects (20 eyes) with open-angle glaucoma with no history of surgery were enrolled. METHODS Ten subjects were randomly assigned to viscocanalostomy according to Stegmanns technique and 10 subjects to a modified Cairns trabeculectomy. A complete ophthalmologic examination was performed the day before surgery and postoperatively. Further visits were scheduled monthly for 6 to 8 months after surgery. MAIN OUTCOME MEASURES Success was defined as intraocular pressure (IOP) between 7 and 20 mmHg, with no medication. RESULTS After a mean follow-up of 6 months (range, 6-8 months), success was obtained in 5 of 10 cases in the trabeculectomy group and in no case in the viscocanalostomy group. With Kaplan-Meiers method, subjects with viscocanalostomy showed shorter postoperative IOP-reduction periods than subjects undergoing trabeculectomy. CONCLUSIONS According to the results of this short-term study, trabeculectomy was more effective than viscocanalostomy in lowering IOP in glaucomatous eyes of white patients.

A prospective randomized trial of viscocanalostomy versus trabeculectomy in open-angle glaucoma: a 1-year follow-up study.

PurposeTo assess the intraocular pressure-lowering efficacy and the postoperative complication profile of viscocanalostomy versus trabeculectomy. Patients and MethodsSixty eyes of 60 patients with medically uncontrolled open-angle glaucoma were randomized either to the viscocanalostomy or to the trabeculectomy group of the trial. Viscocanalostomy was performed according to Stegmanns technique using high-molecular-weight sodium hyaluronate to fill the ostia of the Schlemm canal. For trabeculectomy, a modified Cairns-trabeculectomy was performed. Examinations were performed before surgery and postoperatively daily for 1 week. Follow-up visits were scheduled 1, 6, and 12 months after surgery. ResultsThe mean (SD) preoperative intraocular pressure was 27.1 (7.1) mm Hg for all patients enrolled. One day after surgery, mean (SD) intraocular pressure was 15.9 (5.2) for the trabeculectomy group (P <0.001) and 15.7 (3.6) for the viscocanalostomy group (P <0.001), respectively. The success rate, defined as an intraocular pressure lower than 22 mm Hg without medication, was 56.7% in the trabeculectomy group and 30% in the viscocanalostomy group at 12 months postoperatively (P = 0.041). The number of postoperative complications was lower in the viscocanalostomy group than in the trabeculectomy group. ConclusionsIn eyes with open-angle glaucoma, viscocanalostomy is less effective in reducing intraocular pressure than standard filtering surgery. However, postoperative complications are more frequent after filtering surgery.

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

PurposeIn 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 MethodsThirty-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. ResultsThe 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. ConclusionThis 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.

Development of a Completely Encapsulated Intraocular Pressure Sensor

A completely encapsulated intraocular pressure (IOP) sensor equipped with telemetric signal and energy transfer is introduced integrated into a silicone disc for implantation into the eye. After implantation into enucleated pig eyes and into rabbit eyes in vivo, the IOP was recorded and compared to established techniques of IOP measurement. Pressure chamber tests showed that the sensor functioned correctly after biocompatible encapsulation in polydimethylsiloxane. In vivo and in vitro tests in rabbit and pig eyes demonstrated that the implanted system worked with the same precision as established techniques for IOP determination. The correlation between the measurements with the implanted device and pneumotonometry in several experiments was between 0.9 and 0.99. This device serves as a functioning model for the realization of a telemetric IOP sensor for integration into an artificial intraocular lens. Such a device will open new perspectives, not only in the management of glaucoma, but also in basic research for mechanisms of glaucoma.

Direct costs of glaucoma management following initiation of medical therapy

Abstract ·Background: Economic evaluation of new treatments in the field of glaucoma represents a challenge. In the absence of a clear epidemiological link between intra-ocular pressure (IOP) and disease progression to blindness, the economic impact of treatments that lower IOP on long-term outcome cannot be estimated. As an alternative, effectiveness may be expressed as the ability to control IOP over time, making it possible to estimate the cost-effectiveness of therapies. The objective of this study was to investigate treatment strategies for patients newly diagnosed with primary open-angle glaucoma (POAG) or ocular hypertension (OH) in Germany and to estimate the impact of new topical therapies on the total cost of treatment. ·Methods: We performed a retrospective analysis of 200 randomly selected patient charts in 50 ophthalmology practices. Demographics, diagnoses, IOP and detailed resource utilization over 2 years were collected. Resources were valued independently from the quantitative data collection, and a standard charge from the perspective of the third party payer, as well as a cost from the societal viewpoint, was determined for each item. A Markov model was created to calculate total treatment costs with the new therapy. ·Result: During the 2 years, 54% of patients had their therapy changed at least once. Mean total charge and cost per patient were DM 815 and DM 1274, respectively. Mean IOP at baseline was 31.2 mm at baseline and 18.8 mm after 2 years. IOP at baseline was positively correlated with costs, while IOP reduction after treatment initiation was negatively correlated with costs. Simulations of the effect of new topical therapies on treatment costs to third party payers and to society indicate that a potential reduction or delay of surgical interventions may partly offset the extra cost of the new drugs. ·Conclusion: Observational data for glaucoma treatment indicate a high frequency of treatment changes that are associated with higher costs. New treatments that control IOP effectively over time may thus reduce the cost of patient management. Their cost-effectiveness for managing IOP will depend on both, their price and their effectiveness.

Prognosis of primary ab externo surgery for primary congenital glaucoma

BACKGROUND The strategy of pressure reducing surgery in primary congenital glaucoma has changed over the last decade. Ab externo filtering procedures—for example, trabeculectomy or trabeculotomy combined with trabeculectomy, have now been accepted even as primary intervention. METHODS The authors reviewed 61 eyes in 35 consecutive patients with primary congenital glaucoma, who underwent different types of initial ab externo surgery between 1988 and 1996 (median follow up 36 months) to determine the efficacy of different surgical techniques and the influence of various risk factors. RESULTS Trabeculotomy was performed in 17 eyes (27.9%), trabeculotomy with trabeculectomy in 15 eyes (24.6%), and trabeculectomy in 29 eyes (47.5%). Regarding age, preoperative intraocular pressure, corneal diameter, ocular axial length, and incidence of corneal haze the subgroups were comparable. Success rates of trabeculotomy, trabeculectomy, and a combined procedure did not significantly differ when assessed by life table analysis. Patient age under 3 months (p=0.014) and an ocular axial length of 24 mm or more (p=0.016) proved to be major risk factors for primary ab externo surgery failure. A second operation was necessary in 20 of 61 eyes (32.8%) during follow up. CONCLUSION Prognosis of primary ab externo glaucoma surgery in primary congenital glaucoma seems to be governed more by the individual course and severity of the disease than by modification of surgical techniques.

Bimanual trabecular aspiration in pseudoexfoliation glaucoma: An alternative in nonfiltering glaucoma surgery

OBJECTIVE The primary cause of intraocular pressure (IOP) elevation in pseudoexfoliation glaucoma is obstruction of the intertrabecular spaces by exfoliation material. Previously, the authors reported on a new concept of nonfiltering glaucoma surgery-trabecular aspiration-designed to increase trabecular outflow in pseudoexfoliation glaucoma. In the current study, a description of the modified instrument, its refined surgical technique, and long-term clinical results will be given to substantiate the efficacy of trabecular aspiration in the surgical management of pseudoexfoliation glaucoma. STUDY DESIGN The study design was a prospective and nonrandomized study. PARTICIPANTS A total of 68 eyes of 54 patients suffering from medically uncontrolled pseudoexfoliation glaucoma were treated by bimanual trabecular aspiration. Thirty-four eyes of 28 pseudoexfoliative patients treated by standard trabeculectomy constituted the control group. INTERVENTION Trabecular debris and pigment were cleared with a suction force of 100 to 200 mmHg under light tissue-instrument contact using a modified intraocular aspiration probe. The aspiration cannula is 400 microm in diameter and horizontally angulated at 45 degrees. Irrigation of the anterior chamber was performed via a separate irrigation cannula. MAIN OUTCOME MEASURES The IOP and number of medications before and after surgery were measured. RESULTS In 42 eyes of 36 patients, trabecular aspiration was performed in combination with cataract extraction and lens implantation. The IOP dropped from 32.4 +/- 7.2 mmHg (range, 23-52 mmHg) under maximal tolerated medical therapy before surgery to 18.7 +/- 1.7 mmHg (range, 16-23 mmHg) at 2 years after surgery, with 54% of patients being controlled without medication. In 22 eyes of 19 patients, trabecular aspiration was performed as primary surgical intervention. The IOP dropped from 31.3 +/- 7.1 mmHg (range, 23-42 mmHg) before surgery to 16.8 +/- 3.4 mmHg (range, 12-23 mmHg) at 18 months after surgery, with 45% of patients not taking medication. CONCLUSIONS Bimanual trabecular aspiration is safe and efficacious in decreasing IOP both with and without cataract extraction in pseudoexfoliation glaucoma. However, there seems to be a slight regression in effect over time attributed to undisturbed liberation of exfoliative debris. Argon-laser trabeculoplasty before trabecular aspiration reduces the IOP-lowering effect of this procedure. A prospective, randomized, multicenter study is warranted to finally assess the potential of trabecular aspiration in pseudoexfoliation glaucoma.

Goniocurettage for removing trabecular meshwork: clinical results of a new surgical technique in advanced chronic open-angle glaucoma

PURPOSE To elucidate the long-term outcome of goniocurettage as a new technique in trabecular microsurgery for advanced open-angle glaucoma. METHODS In a prospective, nonrandomized clinical trial, 25 eyes of 25 patients with a mean age +/- SD of 72.7+/-10.1 years (range, 50 to 89 years) with uncontrolled chronic open-angle glaucoma that had undergone failed filtering procedures were treated by goniocurettage. Trabecular tissue was scraped away from the chamber angle by means of an instrument similar to a microchalazion curette (diameter, 300 microm). RESULTS Before surgery, intraocular pressure ranged from 29 to 48 mm Hg (mean +/- SD, 34.7+/-7.1 mm Hg), and mean number of antiglaucoma medications was 2.2+/-0.56. Follow-up averaged (+/-SD) 32.6+/-8.1 months (range, 30 to 45 months). Overall success, defined as postoperative intraocular pressure of 19 mm Hg or less with one pressure-reducing agent, was attained in 15 eyes (60%), with five eyes (20%) being controlled without medication. Considering all successfully treated patients, the mean intraocular pressure was 17.7+/-3.1 mm Hg (range, 10 to 19 mm Hg) at the final visit. Mean intraocular pressure reduction was 17.1+/-7.1 mm Hg in these eyes, representing a net decrease from baseline of 49%. Number of antiglaucoma medications dropped to 0.63+/-0.29. Complications included localized Descemet membrane detachment in five eyes (20%) and moderate anterior chamber bleeding in four eyes (16%). CONCLUSIONS This new surgical technique can effectively control intraocular pressure for long periods of time in patients with open-angle glaucoma and a history of failed filtering procedures. Goniocurettage may be a suitable alternative to surgical treatment of glaucoma patients with excessive conjunctival scarification.

Extraocular application of mitomycin C in a rabbit model: cytotoxic effects on the ciliary body and epithelium

Since prolonged postoperative hypotony has been a frequent complication of glaucomatous filtration surgery in which mitomycin C (MMC) was used, it is important to determine the intraocular toxic effects of the drug. We placed MMC, in concentrations of 0.05, 0.2, and 1.0 mg/mL on the intact sclera of rabbits and obtained the eyes after 1, 7, and 28 days. Examination of the ciliary epithelium by transmission electron microscopy revealed an electron-dense material near the endoplasmic reticulum. Large intracellular vacuoles were present, and the mitochondria appeared swollen. These findings suggest a toxic effect of MMC on the ciliary epithelium in rabbits after extraocular application, possibly decreasing aqueous production.