Safety evaluation of "retina implant alpha IMS"--a prospective clinical trial.

BACKGROUND: To restore vision in patients with retinitis pigmentosa, several types of electronic devices have been developed to stimulate neurons at different levels along the visual pathway. Subretinal stimulation of the retina with the Retina Implant Alpha IMS (Retina Implant AG, Reutlingen, Germany) has been demonstrated to provide useful vision in daily life. Here we evaluated the safety of this device. METHODS: An interventional, prospective, multi-center, single-arm study was conducted in patients with retinitis pigmentosa with the Retina Implant Alpha IMS. The results from the first nine patients of a single center regarding safety of the device are reported. Any untoward medical occurrence related or unrelated to the tested device was documented and evaluated. RESULTS: Nine adult subjects were included in the study at the Tübingen site. Seventy-five adverse events occurred in total, and 53 affected the eye and its adnexa. Thirty-one ocular adverse events had a relationship to the implant that was classified as "certain" while 19 had a probable or possible relationship; three had no relationship to the implant. Thirty-nine ocular adverse events resolved without sequelae, two resolved with sequelae, 11 remained unresolved, and in one the status was unknown. The intensity of ocular adverse events was mild in the majority of cases (n = 45), while six were of moderate and two of severe intensity. There was no non-ocular adverse event with certain relationship to the device. One subject lost light perception (without light localization) in her study eye. CONCLUSIONS: In conclusion, this prospective study, "Safety and Efficacy of Subretinal Implants for Partial Restoration of Vision in Blind Patients," shows that the Retina Implant Alpha IMS is an option for restoring vision using a subretinal stimulation device with a clinically acceptable safety profile.

Visualisation of active subretinal implants with external connections by high-resolution CT.

Two patients carrying an active subretinal implant with extra-ocular parts were examined by high-resolution CT. Cranial scans were acquired in the primary position and in eight additional directions of gaze with eyes open and closed to demonstrate the mobility of the eyeball and the implant within the orbital cavity. Three-dimensional images were constructed to visualise the path of the implant from the retro-auricular space around the lateral orbital rim through the orbit and within the subretinal space up to the device's final para-foveal position. Images were obtainable in high quality, resulting in three-dimensional models illustrating all parts of the implant including the micro-photodiode array at the tip in the subretinal space. The implant followed eye movements in all directions of gaze; eye movements were only minimally restricted as described in previous publications. Since all, except intra-ocular, parts of the implant evade direct examination, CT can be useful to assess the technical integrity and the biocompatibility and biostability of retinal implants.

Dose, timing and frequency of subconjunctival 5-fluorouracil injections after glaucoma filtering surgery.

BACKGROUND: Although adjunctive postoperative 5-fluorouracil (5-FU) injections are known to improve the success rate of glaucoma surgery, it is still unknown what dose, timing and frequency of application will give the best results with respect to the inhibition of postoperative scarring and intraocular pressure regulation. We therefore designed the following retrospective investigation. METHODS: We studied 172 eyes from 172 patients who had undergone trabeculectomy with adjuvant 5-FU-therapy. Variations of dosage, timing and frequency were analysed retrospectively. Surgery was defined as a complete success when the patient reached an intraocular pressure under 21 mmHg and a reduction of 20% 12 months after the operation. A relative success was achieved with these criteria under additional local medication. Not reaching these postoperative criteria for a complete success was classified as failure. RESULTS: On average, adjunctive 5-FU-treatment was started 4.6+/-5.85 days postoperatively. The injections contained between 2 mg and 5 mg FU, and the mean total dose was 26.6+/-13.2 mg (range 5-65 mg). Surgery on 94 patients (54.65%) was classified as "complete success", that on 25 patients (14.53%) was classified as "relative success" and that on 53 eyes (30.81%) was classified as "failure" 12 months (+/-3 months) postoperatively. The best results were obtained when the treatment started on or before the first postoperative day (68.0-71.4% complete success; P<0.05). In contrast, an increase in 5-FU dosage did not result in an increased success rate of trabeculectomy. None of the 172 patients suffered from vision-threatening complications such as endophthalmitis or hypotony maculopathy. CONCLUSION: Early treatment with 5-FU significantly increases the success rates of filtering surgery.