Sven Dinslage

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.

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 ≥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.

Characteristics of Iris and Retinal Pigment Epithelial Cells Cultured on Collagen Type I Membranes

Purpose: Transplantation of pigment epithelial cells is a promising treatment modality to repair retinal damage in age-related macular degeneration. For this purpose, it is necessary to establish cell culture techniques that allow acquisition of proper functional and morphological characteristics by the cells to be transplanted. Methods: Primary retinal pigment epithelial (RPE) and iris pigment epithelial (IPE) cells grown to confluence on collagen membranes were examined for morphology, adhesion, proliferation, apoptosis, as well as viability after ex vivo transplantation. Results: Pigment epithelial cells adhere, proliferate, form monolayers, acquire differentiated properties, and remain viable during transplantation to the subretinal space. Conclusions: Pigment epithelial cells cultured on collagen membranes acquire differentiated characteristics and are amenable to be transplanted as cell monolayers.

A comparative bioavailability study of three conventional eye drops versus a single lyophilisate

Aim: To study the ocular bioavailability of a triple dose, single application of sodium fluorescein to the human anterior segment from a novel drug delivery device. Methods: In a randomised, open label study 22 healthy volunteers applied a single lyophilisate to one eye (+1 minute) and three conventional eye drops (+1, 16, 31 minutes) of fluorescein ophthalmic solution to the fellow eye. The fluorescein dose of the lyophilisate was 204 mg corresponding to three conventional, preservative-free eye drops of 40 ml fluorescein SE Thilo 0.17% (68 μg each) (Alcon). Fluorophotometry was performed (Fluorotron Master II Ocumetrics, USA) before and +15, 30, 45, 60, 120, 180, 240, 300, 360, 420 minutes after application. The fluorescein concentrations of the corneal stroma and mid-anterior chamber were analysed by paired t test. Results: Cornea and anterior chamber mean values (ng/ml) were significantly higher (p<0.018, paired t test) in the lyophilisate group up to 7 hours after application with the exception of +45 minutes. The mean fluorescein bioavailability from the lyophilisate was up to 11 times higher in the cornea and up to 8.7 times higher in the anterior chamber compared with the three preservative-free eye drops. Conclusion: A triple dose was delivered to the human eye with a single lyophilisate application for the first time. A significantly better bioavailability was achieved in the cornea and anterior chamber for up to 7 hours by means of drug application with lyophilisates. The application of medications by means of the lyophilisate will improve the treatment of, for example, glaucoma, bacterial, viral and fungal infections, as well as dry eye syndrome.

Accuracy of intraocular lens power calculation using partial coherence interferometry in patients with high myopia.

Citation information: Roessler GF, Dietlein TS, Plange N, Roepke A‐K, Dinslage S, Walter P, Mazinani BAE. Accuracy of intraocular lens power calculation using partial coherence interferometry in patients with high myopia. Ophthalmic Physiol Opt 2012, 32, 228–233. doi: 10.1111/j.1475‐1313.2012.00903.x

Signal quality of biometry in silicone oil–filled eyes using partial coherence laser interferometry

Purpose: To assess the practical feasibility and signal quality of axial length measurements by partial coherence laser interferometry in silicone oil–filled eyes with previous complicated vitreoretinal surgery. Settings: Department of Ophthalmology, University Cologne, Cologne, Germany. Methods: Using a Zeiss IOLMaster, axial length measurements and signal‐to‐noise ratios of optical biometry in silicone oil–filled eyes (n = 45) and contralateral eyes without tamponade (n = 41) were analyzed. Results: Axial length measurements with signal‐to‐noise ratio ≥2 were feasible in 41 of 45 silicone oil–filled eyes (91%) and 37 of 41 eyes without tamponade (90%). Cataract, central retinal detachment, vitreous hemorrhage, and emulsified oil droplets attached to the intraocular lens were reasons for failure of partial coherence laser interferometry. The signal‐to‐noise ratio of the first 2 measurements was significantly smaller (P = .04) in silicone‐filled eyes (4.4 ± 2.0) than in eyes without tamponade (5.5 ± 3.0). Axial lengths of the oil–filled eye and the contralateral eye showed a significant intraindividual correlation (P<.0001, Spearman r = 0.84). Conclusions: Partial coherence laser interferometry shows good clinical practicability in silicone oil–filled eyes with previous complicated vitreoretinal surgery. Further studies are needed to assess the reliability of these measurements with regard to postoperative refraction after combined oil removal and cataract surgery.

Central and paracentral corneal pachymetry in patients with normal tension glaucoma and ocular hypertension

PurposeThe difference in central corneal thickness among subgroups of glaucoma patients, as well as its influence on Goldmann applanation tonometry, has been well documented in several clinical trials. In the present study, possible similarities and differences between central corneal thickness and corneal thickness of paracentral quadrants in patients with normal tension glaucoma (NTG) and ocular hypertension (OHT) were investigated.MethodsCentral and paracentral corneal thickness was measured by optical slit scan pachymetry (Orbscan II). Fourteen patients (28 eyes) with NTG and 11 patients (22 eyes) with OHT were included in this study. t-Test was performed for statistical analysis. To evaluate overall corneal topography, the mean and SD values of the differences between the central corneal thickness and each peripheral quadrant were analysed.ResultsThe following data was obtained (μm): (central, upper, temporal, nasal, inferior paracentral quadrant): OHT group 617–695–663–687–660. NTG group 568–629–593–612–616. Corneal thickness of all four paracentral quadrants differed significantly between the OHT and NTG groups. There was a more heterogeneous intraindividual pattern of overall corneal topography in the OHT group, and a more heterogeneous pattern of corneal topography among the individuals of the NTG group (interindividual heterogeneity).ConclusionsA comparison of central corneal thickness and paracentral corneal thickness revealed clinically relevant differences between the OHT and NTG groups. The presented data underlines the importance of correlating the site of applanation with the corresponding corneal thickness, especially in OHT patients. It further substantiates the necessity to obtain individual pachymetric data for each NTG patient.

Biodegradable implant for tissue repair after glaucoma drainage device surgery.

Aim/BackgroundTo report a novel technique using biodegradable material to cover exposed glaucoma tube shunts. MethodsA case report of a single patient who underwent drainage tube shunt surgery with the Baerveldt drainage device for intractable glaucoma. Four months post operation the tube became exposed through necrosis of the overlying scleral flap and conjunctiva. The defect was repaired by fixation of the tube to the sclera, with a slice of an ologen implant as a patch, covered by the adjacent conjunctiva. The patient was followed over a period of 1 year after the surgery. ResultsSuccessful, lasting closure of the conjunctival defect was achieved without any side effects or complications. ConclusionsErosion of the drainage tube after shunt surgery is a potentially serious problem. It can be successfully managed using a biodegradable implant as a patch before closing the conjunctiva.

Effect of a capsular tension ring on refractive outcomes in eyes with high myopia

PURPOSE: To evaluate the effect of capsular tension ring (CTR) implantation on refractive outcomes in patients with high myopia. SETTING: University of Cologne, Department of Ophthalmology, Cologne, Germany. DESIGN: Comparative case series. METHODS: The refractive outcomes in myopic eyes were compared between phacoemulsification and IOL implantation with a CTR (CTR group) and without a CTR (control group). Optical biometry (IOLMaster) was obtained. The power of the IOL was used to calculate the predicted postoperative spherical equivalent using the Haigis and SRK/T formulas. The main outcome measures were the mean error and mean absolute error of the refractive prediction error. RESULTS: The mean axial length was 29.1 mm (range 26.5 to 34.1 mm) in the CTR group and 28.2 mm (range 25.6 to 31.1 mm) in the control group. There was no statistically significant difference in the mean absolute refractive prediction error between the CTR group and the control group with the Haigis formula (P = .921) or SRK/T formula (P = .693). However, there was lower variance in the absolute refractive prediction error in the CTR group with both formulas (P = .014 and P = .027, respectively). Intragroup differences between formulas were not statistically significant (CTR, P = .069; control P = .551). CONCLUSIONS: Implantation of a CTR had no consistent effect on refractive outcomes compared with routine phacoemulsification in highly myopic eyes. There was a tendency toward higher precision in outcomes with a CTR. Results indicate IOL power calculation does not have to be changed when a CTR is used. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned.