[Transcorneal electrical stimulation in primary open angle glaucoma]. / Transkorneale Elektrostimulation bei primärem Offenwinkelglaukom.

Recently, reports have been published on the effectiveness of electrical stimulation in patients and experimental animal models with neurodegenerative ocular diseases. Our study included 14 patients with primary open angle glaucoma (POAG), who were randomized into one of three groups with 0% (sham, n = 5), 66% (n = 5) or 150% (n = 4) of their individual electrical phosphene thresholds. Patients were treated with transcorneal electrical stimulation (TES) for 30 min once a week for 6 consecutive weeks. Outcome measures of our study were the detection of possible adverse events and efficacy of TES using DTL electrodes in subjective and objective parameters of visual function under treatment. TES was tolerated well and no serious adverse events were registered relating to the treatment. One single adverse event was registered as appearance of an optic disc hemorrhage of a sham-stimulated eye. In summary, one significant increase of intra-ocular pressure in the 66% group was observed in comparison to the sham group (p = 0.04), without significant differences compared to the 150% group (both sham vs. 150% group and 66% vs. 150% group). This difference (mean difference compared to baseline of -2.33 mm Hg for the sham group and +0.97 mm Hg for the 66% group; REML) was not clinical meaningful. All other findings, including results of the visual field, were not statistically significant different between groups. It was shown that TES using DTL electrodes did not trigger adverse or serious adverse events in the stimulated groups in patients with POAG. Patients with POAG should currently receive TES only under study conditions.

[Ocular electrical stimulation: Therapeutic application and active retinal implants for hereditary retinal degenerations]. / Okuläre elektrische Stimulation : Therapeutische Anwendung und aktive retinale Implantate bei hereditären Netzhautdegenerationen.

BACKGROUND: Electrical stimulation has a long history in ophthalmology. Subthreshold electrical stimulation can have beneficial therapeutic effects on hereditary degenerative retinal diseases. Suprathreshold stimulation is able to elicit visual perceptions and, if multielectrode fields are arranged as an array, usable pictures can be perceived by blind patients. OBJECTIVES: This is a review article on the current situation and studies on therapeutic transcorneal electrical stimulation. Moreover, the challenges, surgical concepts and visual results of active retinal implants are discussed. MATERIAL AND METHODS: This article gives an overview on transcorneal electrical stimulation and active retinal implants based on published results, with special emphasis on the clinical application. RESULTS: The results of initial controlled studies on therapeutic transcorneal electrical stimulation in hereditary retinal diseases were very promising. The largest controlled study so far in patients with retinitis pigmentosa (RP) has yielded many positive trends and some significant improvements in electrophysiological data. Currently, two retinal implants have regulatory approval, the Argus II retinal prosthesis system® (SecondSight®) and the Alpha-IMS© (Retina Implant AG). Both systems can be used to improve visual perception and under test conditions can achieve visual acuities of 0.02 and 0.04, respectively. CONCLUSION: In-depth analyses and follow-up studies in larger patient groups are currently planned to definitively clarify the potential of therapeutic transcorneal electrical stimulation in RP patients. The challenges of currently available active retinal implants are the technical biostability and the limited spatial resolution.

[Development and first results of fast and cost-effective examination methods for an ophthalmological screening within the National Cohort]. / Entwicklung und erste Anwendungserfahrungen einer schnellen und kostengünstigen ophthalmologischen Untersuchung für die Nationale Kohorte.

BACKGROUND: For an implemented ophthalmological screening within a German long-term cohort study (National Cohort) simple and effective methods for an examination of visual acuity and for non-mydriatic retina photografies should be evaluated. Furthermore standard operating-procedures (SOP) should be developed. METHODS: In the years 2011 and 2012 pinhole visual acuity measurements and automated retina photographies (DRS, CenterVue S. p. a., Padua, Italy) were made at three different epidemiological study centers within Germany. Furthermore, anterior segment images were taken by the camera. Standard operating procedures (SOP) regarding the ophthalmological screening were developed and evaluated within the study. The main question was whether it is possible to implement the screening methods within the National Cohort. Further main outcomes were quality and interpretability of the taken images. RESULTS: 457 subjects (914 eyes) were examined within the investigation. Median VA was 0.8 for right and left eyes (p > 0.42). Image quality of the photographies was good in 491 cases (54 %), fair in 239 cases (26 %) and bad in 179 cases (20 %). The usability of the images was without limitations in 686 cases (75 %), limited in 152 cases (17 %) and not given in 71 cases (8 %). Increasing age of the subjects was slightly correlated with decreasing image quality (r = 0.26) and decreasing image usability (r = 0.2). Anterior segment photographies were usable in 176 eyes (56 %). CONCLUSION: The developed screening method fulfilled the specifications of the National Cohort. The used pinhole visual acuity examination was fast and cheap. Image quality and usability of the retina photographies could be improved with prolonged pupil recovery times. The quality of the anterior segment images could not fulfill the expectations and were taken out of the further examinations of the ophthalmological screening. The written SOP showed good acceptance within the investigators' daily routine. The ophthalmological screening within the National Cohort generates information (e. g., pathologies of the vessels or of the retina) which are useful not only from an ophthalmological point of view.

[Effects of transcorneal electrical stimulation in patients with Stargardt's disease]. / Transkorneale Elektrostimulation bei Patienten mit Morbus Stargardt.

Stargardt's disease is an autosomal recessive inherited juvenile macular degeneration and at present no acknowledged science-based therapy is available for these patients. Recently, reports have been published on the effectiveness of electrical stimulation in experimental animal models and in patients with neurodegenerative ocular disease, particularly retinitis pigmentosa. This study included 12 patients with Stargardt's disease who were randomized into one of three groups (n = 4) with 0% (sham), 66% or 150% of the individual electrically stimulated phosphene threshold. Outcome measures of the study were safety and efficacy of transcorneal electrical stimulation (TES) with DTL electrodes in subjective and objective parameters of visual function under therapy. In general TES was well tolerated and no adverse or serious events were noted. Neither Ganzfeld, multifocal ERG, OCT nor visual field testing showed statistically significant changes in any group.

["Do you have a remedy for macular degeneration?" A field study about the advice given on dietary supplementation in 60 German pharmacies]. / "Haben Sie ein Mittel gegen Makuladegeneration?" Eine Feldstudie in 60 deutschen Apotheken über die Beratung zu Nahrungsergänzungsmitteln.

PURPOSE: Since completion of the AREDS study, evidence has accumulated to suggest that some form of dietary supplementation may be of value in special individuals who are at risk of progressive age-related macular degeneration (ARMD). We wanted to find out which of the many supplements available are recommended in practice and which instructions, promises, and purchasing arguments are used by German pharmacies. METHODS: A blinded consultation following a standardized protocol was carried out in 60 pharmacies. RESULTS: In 36 pharmacies specific products for dietary supplementation were recommended, but the dosage never complied with the AREDS study, and in 24 pharmacies, the necessity for a medical examination or consultation with an ophthalmologist was not mentioned. Possible interactions with other drugs or side effects were generally excluded. CONCLUSIONS: Potential risks of supplement intake were underestimated. Medical knowledge of the most frequent cause of blindness in the Western world was insufficient. A clear policy of recommendations according to evidence-based criteria is needed.

Histopathological analysis in experimental macular surgery with trypan blue.

AIM: To analyse the effect of trypan blue on the retina in an experimental setting of macular surgery. METHODS: Porcine eyes were used within 3 hours after death. The eyes were hemisected and the vitreous removed. Trypan blue (0.15%) was applied over the trephined posterior pole, whereas the rest of the eye cup was filled with a balanced salt solution (BSS). The dye and the BSS were removed after 1 minute and the complete eye cup irrigated and filled with fresh BSS. Both the treated and untreated retinas were illuminated with a standard surgical light pipe and source at maximum power for 10 minutes. Both the trypan blue exposed retina and the non-treated surrounding retina were processed for histology. RESULTS: Exposure of the retina to trypan blue for 1 minute, followed by illumination caused no histologically detectable damage compared to the controls. No microarchitectural disorganisation, cellular disruption, or affection of the vitreoretinal interface was detected. CONCLUSIONS: These findings indicate that a 1 minute exposure of trypan blue followed by illumination does not cause an acute morphologically detectable toxic effect on the porcine retina.

Adjunctive hyperbaric oxygenation in macular edema of vascular origin.

Macular edema (ME) is a primary reason for permanent decreases of visual acuity (VA) in diabetic retinopathy and retinal vein occlusions. The standard treatment (photocoagulation, rheological treatment) provide only a limited success. We have therefore studied the additional use of hyperbaric oxygenation (HBO2) in patients with persistent ME. Five patients (1 female, 4 male; 7 eyes) were treated by adjunctive HBO2. The average age of the patients was 60.6 (38.9-76.8) yr. The VA was measured with Early Treatment Diabetic Retinopathy Study charts before and after HBO2 with a monthly follow up. Fluorescein angiography was performed before and after HBO2 with a follow up every 3 mo. Each patient received 10-30 HBO2 treatments (median 15). The follow-up period was 15 mo. for every patient. The mean increase in VA was 3.5 (2-4) lines after HBO2. Retinal photocoagulation was performed in six eyes. Diabetic macular edemas showed no morphologic change, while ME originating from retinal vein occlusions (CME) regressed. The VA in our patients with ME of vascular origin seemed to improve with HBO2. Photocoagulation was necessary in most cases. Visual function correlated with the angiographic presentation only for CME.

Primary use of silicone oil tamponade in the management of perforating globe injury secondary to inadvertent local anaesthesia injection for ophthalmic surgery.

Perforating and penetrating globe injuries secondary to peribulbar and retrobulbar anaesthesia are often complicated by vitreous haemorrhage and retinal detachment. We describe the effectiveness of primary silicone oil tamponade in the repair of three perforated globes secondary to local anaesthesia for ophthalmic surgery. Three patients with axial myopia had peribulbar and retrobulbar anaesthesia for extracapsular cataract extraction (two patients) and cryotherapy (one patient). All eyes sustained a vitreous haemorrhage obscuring the view to the fundus. Retinal detachments were detected by B-scan ultrasound. In all eyes, scleral buckling, pars plana vitrectomy and silicone oil tamponade were performed as a primary surgical procedure. All the patients had complete anatomic reposition. In two patients, after two years follow-up, visual acuity was between 6/12 to 6/36 with the retina attached and no proliferative vitreoretinopathy (PVR). The third patient had blind painful eye and enucleation was performed. Primary use of silicone oil tamponade, in the management of perforated globe with retinal detachment due to local anaesthesia injection, is recommended.