New suture probe canaloplasty combined with suprachoroidal collagen implantation.

PURPOSE: To present the modified surgery technique of new suture probe canaloplasty with a specially prepared monofilament 4.0 polypropylene suture combined with suprachoroidal drainage (ScD) and collagen sheet implantation for non-penetrating glaucoma surgery. METHODS: Prospective study with a twelve months follow-up. A standard 4/0 polypropylene suture (ProleneTM by Ethicon; thickness: approximately 250 m) is cut and shaped with an ophthalmic knife (MANI® Crescent Knife, Mani Inc 8-3 Kiyohara Industrial Park, Utsunomiya, Tochigi 321-3231, Japan) to create a blunt end without sharp or compressed edges. This improves suture probe canaloplasty by providing a more stable and smoother probing device. Schlemm's canal is prepared using the standard technique of canaloplasty with suprachoroidal drainage. Then, instead of using the canaloplasty microcatheter or the previously published 6/0 double-helix suture, Schlemm's canal is probed with the blunt ending of the 4/0 Prolene suture. After successful 360-degree probing, a doubled 10/0 polypropylene tension suture is threaded through the tip of the 4/0 suture. The 4/0 suture is then pulled back and the 10/0 tension sutures are tied at both ends to tension Schlemm's canal. A special collagen sheet (Ologen®) is placed in suprachoroidal space, and the scleral flap is firmly sewed. RESULTS: 115 eyes were included in this prospective study. In 113 cases the Schlemm's canal could completely be probed with the suture probe and canaloplasty with ScD and collagen sheet implantation succeeded. In two cases the intervention was transformed to 360-degree suture trabeculotomy due to an intraoperative cheese-wiring. Twelve months after successful new suture probe canaloplasty with ScD and Collagen Implantation the IOP had decreased by 37.1% (from 21.6 ± 6.0 mmHg with 3.3 different IOP lowering eye drops to 13.5 ± 3.5 mmHg with 1.0 eye drops). 16 Patients did not achieve sufficient IOP levels and underwent 360-degree suture trabeculotomy during the follow-up. One patient had to be treated with further glaucoma surgery to achieve a sufficient IOP level. Complications were hyphema, postoperative IOP elevation and transient hypotony. No serious or sight-threatening complications occurred. CONCLUSION: New suture probe canaloplasty with ScD and collagen sheet implantation yields the opportunity to conduct a cost-effective canaloplasty easier and less complicated than with the previously described method with the twisted 6/0 suture. The safety profile and IOP lowering effect is comparable. In cases where complete probing fails, there is still the opportunity to switch to suture trabeculotomy over the majorly probed part of Schlemm's canal. The pressure lowering effect of the deep sclerectomy with ScD and suprachoroidal collagen sheet implant seems to have an additional impact on the sufficient pressure lowering procedure.

Comparison of preloaded grafts for Descemet membrane endothelial keratoplasty (DMEK) in a novel preloaded transport cartridge compared to conventional precut grafts.

To determine the safety and graft quality of eye bank precut and preloaded grafts for Descemet membrane endothelial keratoplasty (DMEK) after storage and shipping in a novel preloaded transport cartridge compared to precut grafts in a conventional viewing chamber. In this laboratory proof-of-concept study, 29 human donor corneas that were unsuitable for transplantation with a mean endothelial cell density of 1948 ± 260 cells/mm2 were prepared using liquid bubble technique for producing precut lamellar grafts. The grafts were either preloaded into novel transport cartridge (n = 16) or transferred into conventional Krolman viewing chamber (control, n = 13). Grafts were stored for 24 or 48 h in dextran-containing medium at room temperature and subjected to a shipping simulation. Endothelial cell loss (ECL) and morphology were determined at different steps. Endothelial cell viability staining was performed with calcein dye. Mean ECL in the preloaded transport cartridge was 0.7% ± 1.2% after 24 h and 3.4% ± 1.2% (p = 0.006) after 48 h storage and injection. In the control group the ECL was mean 1.6% ± 2.7% after 24 h compared to 3.7% ± 0.9% (p = 0.042) after 48 h. The slightly higher endothelial cell loss in the viewing chamber group after 48 h was not statistically significant compared to the preloaded transport cartridge (p = 0.8). Calcein staining was comparably low in all groups and correlated with the low ECL in both groups. DMEK grafts can be preloaded into a novel transport cartridge using a "no touch" technique, stored and shipped for up to 2 days in dextran-containing medium without significant ECL.

Catheter-independent suture probe canaloplasty with suprachoroidal drainage.

PURPOSE: To introduce the novel technique of suture probe canaloplasty with suprachoroidal drainage (SCD) as a catheter-independent and cost-saving method to perform non-penetrating glaucoma surgery. METHODS: Prospective interventional study with a 12-month follow-up. A standard 6/0 polypropylene suture is twisted in a special manner to create a double helix with a small loop at its end. Then canaloplasty with SCD is performed, but instead of using the standard canaloplasty catheter, Schlemm's canal is probed with the twisted suture. After 360° probing, a 10/0 polypropylene suture is thread through the loop and the twisted 6/0 suture is pulled backwards through Schlemm's canal. The 10/0 suture in Schlemm's canal is tied firmly and hyaluronic acid is injected into the suprachoroidal space. RESULTS: In total, 74 eyes that underwent suture probe canaloplasty with SCD were included. In 57 cases, probing of Schlemm's canal with the twisted 6/0 suture succeeded. Seventeen eyes had adhesions in Schlemm's canal which made probing with the suture impossible so that the surgeon switched in 12 cases to microcatheter-guided canaloplasty with SCD. While this was successful in five further cases, the adhesions seemed surely not be overcome and SCD with collagen sheet implantation was directly performed. In four additional cases after successful probing, the suture cut through trabecular meshwork; hence a 360° suture trabeculotomy was performed. After successful suture probe canaloplasty with SCD, intraocular pressure (IOP) decreased by 39.2% (from 19.8 ± 4.3 mmHg with 3.4 ± 0.7 different IOP-lowering eye drops to 12.0 ± 1.9 mmHg with 0.6 ± 0.9 eye drops). Three patients did not achieve sufficient IOP levels and, therefore, underwent 360° suture trabeculotomy during follow-up. No serious or sight-threatening complications occurred. CONCLUSION: Suture probe canaloplasty + SCD yields the opportunity to conduct canaloplasty with SCD more cost-effectively with a safety profile and IOP-lowering effect comparable to conventional canaloplasty. In cases where probing with the suture fails. there still remains the option to use a conventional microcatheter or to switch to SCD with collagen sheet implantation.

NEGATIVE EFFECTS OF VITAL DYES AFTER UNEVENTFUL VITREOMACULAR SURGERY.

PURPOSE: Vital dyes have become a clinical standard during chromovitrectomy but toxicity remains an issue. We compared the clinical outcome of one supposedly toxic vital dye (AV 17 with 5% mannitol) with a standard vital dye (MBB Dual) and performed a power analysis for future comparative studies. METHODS: Retrospective analysis of 270 eyes after chromovitrectomy with internal limiting membrane peeling because of macular holes. Primary endpoint was loss in BCVA >2 lines and photoreceptor atrophy as seen on optical coherence tomography examination. RESULTS: In 173 eyes, staining of the epiretinal membrane and extracellular matrix was performed using MBB (Group A), and in 97 using AV 17-M (Group B). The mean BCVA was not significantly different after more than 3 months and also not in the early postoperative period after surgery between Group A and Group B. The number of patients suffering from a decline in BCVA of two lines and more was not significantly higher in patients of Group B. There was not a significantly higher percentage of patients with an inner segment/outer segment defect. CONCLUSION: Our rather homogeneous study showed no significant difference between both dyes. Thousand five hundred patients would need to be examined to find a significant difference in future studies.

One Year Results of the Preserflo MicroShunt Implantation for Refractory Glaucoma.

PRCIS: The Preserflo MicroShunt is an effective method to achieve a satisfying intraocular pressure (IOP) reduction in patients with complicated forms of glaucoma. PURPOSE: To evaluate the efficacy and safety of the Preserflo MicroShunt with mitomycin C in patients with complicated glaucoma. METHODS: This prospective interventional study included all patients that underwent Preserflo MicroShunt Implantation between April 2019 and January 2021 to treat severe and therapy refractory glaucoma. The patients either suffered from primary open angle glaucoma with already failed incisional glaucoma surgery or presented severe forms of secondary glaucoma (eg, after penetrating keratoplasty or globe penetrating injury). Primary endpoint was the IOP-lowering effect and the success rate after 12 months. Secondary endpoint was the occurrence of intraoperative or postoperative complications. Complete success was defined as reaching the target IOP (>6 mm Hg and <14 mm Hg) without additional IOP-lowering medication whereas qualified success was attained with the same IOP target regardless of the medication. RESULTS: A total of 40 eyes of 38 patients were enrolled. After 12 months 85.7% of the eyes achieved complete success with an average IOP of 10.5 ± 2.0 mm Hg, without the use of glaucoma eye drops. The average IOP reduction was 58.4% from baseline. In 5 cases (12.5%) failure occurred as revisional surgery was required. CONCLUSION: The Preserflo MicroShunt for refractory glaucoma cases achieved a high complete success rate without additional medication at 1 year. Revisional surgery was needed in some cases and long-term studies are needed.

First Simultaneous Explantation and Re-Implantation of an Argus II Retinal Prosthesis System.

A 59-year-old blind woman with retinitis pigmentosa had undergone implantation of an Argus II system without complications and took advantage of the system for 7 months. Due to a technical error of the system, the glasses of the prosthesis developed increased heat generation, making the use of the system unbearable. Because of the initial satisfaction and high motivation of the patient, it was decided to strive for an implant exchange. In a 4-hour surgery session, the implant was removed and a new system was implanted. Hereby, several critical surgery steps could be identified that are important to consider for future surgeries. Besides a strong fibrotic scarring of conjunctiva and tenon aggravating the extraction of the extraocular components, the preparation of the sclerotomy proved to be difficult for achieving water tightness. Furthermore, the extraction of the retinal tack and the repositioning of the new array were challenging steps. During the postoperative course, a severe hemorrhagic choroidal detachment occurred but resolved without surgical intervention. The implant was well-placed and showed good function. The exchange of an Argus II is feasible, however, with the challenge of hypotony and hemorrhage as well as possible fibrosis complicating the repositioning of the chip. [Ophthalmic Surg Lasers Imaging Retina. 2019;50:462-465.].

Precut DMEK Using Dextran-Containing Storage Medium Is Equivalent to Conventional DMEK: A Prospective Pilot Study.

PURPOSE: To compare the clinical outcome after Descemet membrane endothelial keratoplasty (DMEK) either as precut or conventional Descemet membrane graft preparation under standard European eye bank organ culture conditions. METHODS: This was a prospective pilot study of patients receiving either precut or conventional DMEK. Graft preparation was performed using the liquid bubble technique. Precut grafts (n = 22) were prepared 1 day before surgery in the eye bank and stored in dextran-containing organ culture medium within a transport viewing chamber. Conventional grafts (n = 29) were prepared directly before surgery. End point criteria included the endothelial cell count (ECC), central corneal thickness, graft rejection rate, rebubbling rate, and best-corrected visual acuity after 1, 3, and 6 months. RESULTS: A post hoc matched analysis revealed no statistically significant differences between the 2 groups. The ECC in the precut and conventional groups was comparable with an EC loss of 34% and 35%, respectively, after 6 months. The early graft failure rate, best-corrected visual acuity, and central corneal thickness were comparable between the 2 groups. CONCLUSIONS: This pilot study shows a comparable clinical outcome after DMEK surgery for precut Descemet membrane grafts versus conventionally prepared grafts, using the liquid bubble preparation technique and storage conditions with dextran-containing medium.

Impact of 10% SF6 Gas Compared to 100% Air Tamponade in Descemet's Membrane Endothelial Keratoplasty.

PURPOSE: To compare the clinical outcomes following Descemet's membrane endothelial keratoplasty (DMEK) with 100% air tamponade versus 10% sulfur hexafluoride (SF6) tamponade. METHODS: Retrospective analysis of 108 consecutive DMEK cases subdivided by anterior chamber tamponade with 54 eyes receiving 10% SF6 and 54 eyes receiving 100% air injection. A post-hoc matched analysis revealed no statistically significant differences between the groups. The main outcome measurements were the complication rate, including intra- and postoperative complications and graft detachment rate requiring re-bubbling. Clinical outcome included best-corrected visual acuity (BCVA), endothelial cell count (ECC), and central corneal thickness (CCT) measured 1, 3, and 6 months after DMEK surgery. RESULTS: The graft detachment rate with consecutive re-bubbling was 18.5% in the air group and 22.2% in the SF6 group (p = 0.2). Remaining small peripheral graft detachments with a clear cornea occurred more often in the 100% air group (air: 22.2%; 12/54, 6/12 inferior compared to SF6: 7.4%; 4/54, 2/4 inferior; p = 0.06). The primary graft failure rate was comparable between the two groups. No complete graft detachment occurred. Outcome results for BCVA, ECC, and CCT at all follow-up time points were comparable between the two groups. CONCLUSION: The clinical outcomes (including re-bubbling rate, primary graft failure rate, and endothelial cell loss) were comparable with 100% air versus 10% SF6 tamponade, whereas other studies suggest that a higher SF6 concentration (20%) may result in a lower re-bubbling rate.

Clinical Comparison of Two Methods of Graft Preparation in Descemet Membrane Endothelial Keratoplasty.

PURPOSE: Descemet membrane endothelial keratoplasty (DMEK) has been improved over the last decade. The aim of this study was to compare the clinical outcome of the recently introduced liquid bubble method compared to the standard manual preparation. METHODS: This retrospective study evaluated the outcome of 200 patients after DMEK surgery using two different graft preparation techniques. Ninety-six DMEK were prepared by manual dissection and 104 by the novel liquid bubble technique. The mean follow-up time was 13.7 months (SD ± 8, range 6-36 months). RESULTS: Best corrected mean visual acuity (BCVA) increased for all patients statistically significant from baseline 0.85 logMAR (SD ± 0.5) to 0.26 logMAR (SD ± 0.27) at the final follow-up (Wilcoxon, p = 0.001). Subgroup analyses of BCVA at the final follow-up between manual dissection and liquid bubble preparation showed no statistically significant difference (Mann-Whitney U Test, p = 0.64). The mean central corneal thickness was not statistically different (manual dissection: 539 µm, SD ± 68 µm and liquid bubble technique: 534 µm, SD ± 52 µm,) between the two groups (Mann-Whitney U Test, p = 0.64). At the final follow-up, mean endothelial cell count of donor grafts was statistically not significant different at the final follow-up with 1761 cells/mm2 (-30.7%, SD ± 352) for manual dissection compared to liquid bubble technique with 1749 cells/mm2 (-29.9%, SD ± 501) (Mann-Whitney U-Test, p = 0.73). The re-DMEK rate was comparable for manual dissection with 8 cases (8.3%) and 7 cases (6.7%) for liquid bubble dissection (p = 0.69, Chi-Square Test). CONCLUSION: Regarding the clinical outcome, we did not find a statistical significant difference between manual dissection and liquid bubble graft preparation. Both preparation techniques lead to an equivalent clinical outcome after DMEK surgery.