Antonis Koutsonas

Implantation of a Novel Telemetric Intraocular Pressure Sensor in Patients With Glaucoma (ARGOS Study): 1-Year Results

PURPOSE We investigated the safety of a telemetric IOP sensor and the accuracy of its IOP measurements in six patients with open-angle glaucoma and cataract. METHODS The study design was a prospective, single-center clinical trial. Here we present 1-year follow-up data. A ring-shaped telemetric IOP sensor was implanted in the ciliary sulcus after implantation of the intracapsular lens, during planned cataract surgery. The sensor is encapsulated in silicone rubber and consists of a miniature device with eight pressure-sensitive capacitors and a circular microcoil antenna. IOP measurements are performed with a reader unit held in front of the eye. IOP is calculated as the differences between the absolute pressure inside the eye (pressure sensor) and that outside the eye (reader unit). RESULTS The sensor was successfully implanted in all patients. Four patients developed sterile anterior chamber inflammation that resolved completely within 9 days after surgery with anti-inflammatory treatment. All patients showed mild to moderate pupillary distortion and pigment dispersion after surgery. Telemetric IOP measurement was performed in all patients at all visits, and the patients successfully performed self-tonometry at home after receiving instructions. Telemetric IOP values showed similar profiles compared to those of Goldmann applanation tonometry (GAT). Three patients showed a relevant IOP step during follow-up, and in one patient, negative values were obtained throughout the study. CONCLUSIONS Despite early postoperative anterior chamber inflammation, the IOP sensor was well tolerated by all patients. We describe the first prospective clinical study of a noncontact IOP sensor that potentially enables continuous IOP monitoring in patients with glaucoma. The sensor shape and size needs to be adapted to avoid pupillary distortion and to confirm that IOP measurements are accurately recorded in comparison to those of GAT. ( www.germanctr.de; number DRKS00003335.).

Management of Intraocular Hypertension During Hemodialysis by Intravenous Glucose Administration

A 64-year-old woman with end-stage renal disease and retinopathy secondary to type 2 diabetes mellitus presented with recurrent episodes of left ocular pain and acute loss of visual acuity during hemodialysis. During these episodes, markedly elevated intraocular pressures were measured. Several local and systemic antiglaucoma drugs were administered without improvement of intraocular pressure, resulting in the necessity of a glaucoma drainage device (Ahmed valve). Due to a local infection, it had to be removed, after which intraocular pressure elevations recurred during hemodialysis. Assuming that intraocular changes in osmolality during hemodialysis caused the intraocular pressure increases, intradialytic administration of a 20% glucose solution (100mL/h) was initiated. This completely abrogated the development of both intraocular pain and increases in intraocular pressure.

Three-Year Follow-Up of Trabeculectomy with 5-Fluorouracil

Purpose: To evaluate the long-term outcome of trabeculectomy with intra- and postoperative 5-fluorouracil (5-FU) application in glaucoma. Methods: Eighty-six patients with glaucoma planned for primary trabeculectomy with 5-FU and a minimum follow-up of 3 years were retrospectively analyzed. Success rates, postsurgical 5-FU injections, needling procedures, and complications were analyzed. Results: Mean intraocular pressure (IOP) decreased from 27.2 ± 6.7 to 13.2 ± 4.2 mm Hg at 1 year and 13.8 ± 3.7 mm Hg at the 3-year follow-up. The complete success rates (no IOP-lowering medication) were 83, 79, 73, and 45% at 1 year for IOP ≤21, ≤18, ≤16, and ≤12 mm Hg, respectively, and 64, 59, 56, and 20% for these criteria at 3 years. The average number of medications decreased from preoperatively 2.9 ± 1.4 to 0.2 ± 0.5 at 1 year and 0.7 ± 1.1 at 3 years. During the first 6 months, subconjunctival 5-FU injections were performed in 49 cases. Eleven patients underwent bleb needling during the first 6 months and 13 patients underwent the procedure between the 6th month and the 3rd year. Malignant glaucoma and bleb-related endophthalmitis occurred in 1 patient each. Conclusions: Trabeculectomy with 5-FU is an efficient surgical procedure for glaucoma treatment when combined with intensified postsurgical care.

Selbsttonometrie mit einem telemetrischen, intraokularen Drucksensor bei Patienten mit Glaukom

BACKGROUND Accurate acquisition of intraocular pressure (IOP) data, particularly short-term and long-term fluctuations, plays an important role in the medical care of glaucoma patients. Non-invasive self-tonometry with a telemetric IOP sensor can provide important data on the individual IOP profile. METHODS Within the framework of a prospective, single-centre pilot clinical trial, a ring-shaped telemetric IOP sensor was inserted into the ciliary sulcus after implantation of the intracapsular lens during planned cataract surgery. In accordance with the protocol, at the 5-month visit, all patients received a reading unit for one-month self-tonometry assessment. All patients were asked to measure the IOP at least once daily, and, if possible, at many different times. The first IOP measurement of each day was evaluated (covering one measurement daily per patient on 20 different days within the assessment interval). Furthermore, IOP data were analysed according to the time of day, divided into early phase (5 am to 11 am), midday (11 am to 4 pm) and late phase (4 am to 11 pm) (patients with at least 10 measurements and max. 20 measurements were included). Descriptive statistics of the original ARGOS system values were calculated, with evaluation of the percentiles and presentation in box plots. RESULTS All patients successfully performed self-tonometry at home after receiving brief instructions. The first IOP measurement of each day covered a very wide interindividual range (between 3.1 mmHg in patient 5 and 21.7 mmHg in patient 4). Analysis of IOP values by time of day showed that patient 1 had significantly higher IOP values in the late day phase. For patient 5, the highest values were at midday. Patients 3 and 4 showed no significant fluctuations during the day. CONCLUSIONS Self-tonometry encourages patients to be actively involved in the management of their own illness and allows non-invasive assessment of IOP at different times and during diverse activities. However, the analysis and interpretation of these new data require further study, especially in relation to Goldmann applanation tonometry.

A case of siderosis bulbi without a radiologically detectable foreign body.

C 1. Markowitz SN, Reyes VS. Microperimetry and clinical practice: an evidence based review. Can J Ophthalmol. Online 24 Oct 2012. DOI: 10.1016/j.jcjo.2012.03.004. 2. Markowitz SN. Principles of modern low vision rehabilitation. Can J Ophthalmology. 2006;41:289-312. 3. Stone EM, Newman NJ, Miller NR, et al. Visual recovery in patients with Leber’s hereditary optic neuropathy and the 11778 mutation. J Clin Neuroophthalmol. 1992;12:10-4. 4. Markowitz SN, Reyes SV, Li Sheng. The use of prisms for vision rehabilitation after macular function loss: an evidence based study. Acta Ophthalmologica. In press.

Long-term follow-up after implantation of a telemetric intraocular pressure sensor in patients with glaucoma: a safety report: Long-term ocular pressure sensor follow-up

To investigate the long‐term safety of a novel intraocular telemetric pressure sensor.

Effects of coagulation on the autofluorescence pattern of ARPE-19 cells: an in vitro study

Objective: Changes in fundus autofluorescence (AF) are observed in various retinal disorders. Lipofuscin accumulation within the retinal pigment epithelium (RPE) is a source of fundus AF (FAF); however, the causes of short-term increases in FAF observed in inflammatory conditions or after laser treatment are unknown. Here, we describe an RPE cell culture model that is useful for investigations of FAF. Methods: ARPE-19 cells were cultured in 2-well chamber slides. Cells were exposed to isolated rabbit photoreceptor outer segments (POS) to mimic in vivo phagocytic activity. The AF of RPE cells exposed to POS was measured before and after focal coagulation of the cultures. AF was measured over a period of 4 weeks. Cell lysates were examined by two-dimensional (2D) gel electrophoresis and mass spectrometry analysis. Results: The exposure of ARPE cells to POS did not lead to increased AF; however, after coagulation, cells exposed to POS showed a statistically significant increase in AF (p < 0.05). 2D electrophoresis of the cell lysates revealed changes in 3 proteins. One of these proteins, identified by mass spectrometry as ezrin-radixin-moesin-binding phosphoprotein 50, was reduced in the coagulated cell population. Conclusions: We have established an in vitro model of RPE cells in culture that can be used to evaluate the development of AF and changes in cellular proteins that accompany laser photocoagulation.