Microinterventional system for robot-assisted gonioscopic surgery- technical feasibility and preclinical evaluation in synthetic eye models.

BACKGROUND: Preclinical technical feasibility study of robot-assisted microinvasive glaucoma surgery using a novel ophthalmic robot-assisted surgery system. METHODS: Feasibility was assessed in synthetic eye models in two stages: Stage I, nonimplantable robot-assisted goniotomy; and Stage II, robot-assisted stent implantation using a trabecular bypass stent. Robot-assisted interventions were subsequently compared to the manual approach. RESULTS: Stage I: Two surgeons completed 10 trials each of ab-interno sectoral goniotomy with and without robotic assistance for at least 3 clock hours using a standard goniotomy knife and more than 10 clock hours of extended goniotomy using a flexible, guided goniotomy instrument. Stage II: Trabecular bypass stent deployment was successfully achieved in 100% of the attempts with and without robotic assistance. Surgical time was recorded and compared between the robotic-assisted and the manual approach. CONCLUSIONS: A system for robot-assisted microinvasive glaucoma surgery can successfully achieve implantable and nonimplantable interventions in the anterior segment. This is the first known demonstration of the feasibility of robot-assisted glaucoma surgery.

Advantages of robotic assistance over a manual approach in simulated subretinal injections and its relevance for gene therapy.

Subretinal injection is a method for gene delivery to treat genetic diseases of the photoreceptors and retinal pigment epithelium. A reflux-free subretinal injection is important to allow effective, safe, and cost-effective gene therapy to the retina. We report on a comparison between manual and robotic assistance in simulated subretinal injections using an artificial retina model. Nine surgeons carried out the procedure with and without the Preceyes Surgical System, using an OPMI Lumera 700 Zeiss surgical microscope equipped with intra-operative optical coherence tomography. Success in creating a bleb without reflux, injection duration, drift, tremor, and increase in the diameter of the puncture hole were analyzed. Robotic assistance improved drift (median 16 vs 212 µm), tremor (median 1 vs 18 µm), enlargement of the retinal hole, and allowed for prolonged injection times (median 52 vs 29 sec). Robotic assistance allowed higher rate of bleb formation (8/9 vs 4/9 attempts) with a moderate reduction in reflux (7/9 vs 8/9 attempts) in this artificial model. Robotic assistance can significantly contribute to subretinal injections and provide quantifiable parameters in assessing surgical and clinical success of novel retinal gene therapies.

Refractory post-surgical cystoid macular edema managed following suprachoroidal microcatheterization and delivery of triamcinolone.

BACKGROUND: Post-surgical macular edema (ME) is a common cause of prolonged visual impairment. Here we report on the feasibility and clinical outcomes from the use of a novel suprachoroidal microcatheter to treat post-surgical chronic ME by the posterior suprachoroidal placement of a triamcinolone acetonide (TA) suspension. METHODS: Two patients were catheterized with the Oxulumis suprachoroidal delivery system on two separate occasions starting 5 and 10 mm posterior to the limbus. The catheter only remains in the suprachoroidal space for the time of the drug administration. Visual acuity and spectral domain optical coherence tomography (SD-OCT) changes were followed over several weeks to months to determine the duration of ME resolution. RESULTS: Suprachoroidal microcatheterization for posterior delivery of triamcinolone was possible in all attempts using the illuminated Oxulumis catheter. No reflux, scleral or choroidal trauma was observed. There was no intraocular pressure rise during the follow-up period. The triamcinolone deposit was visible on infrared imaging and on SD-OCT a choroidal elevation was visible. Both progressively disappeared over time. A rapid resolution of ME associated with improved vision was observed following each injection for 3 to 7 months with a TA dose of 2.4 mg or 4 mg. CONCLUSIONS: In these patients with poorly responsive ME, posterior suprachoroidal TA led to a visible suprachoroidal drug deposit and prolonged visual improvement. The Oxulumis microcatheterization device performed as expected and was not associated with any complications.

Robotic Assistance for Intraocular Microsurgery: Challenges and Perspectives.

Intraocular surgery, one of the most challenging discipline of microsurgery, requires sensory and motor skills at the limits of human physiological capabilities combined with tremendously difficult requirements for accuracy and steadiness. Nowadays, robotics combined with advanced imaging has opened conspicuous and significant directions in advancing the field of intraocular microsurgery. Having patient treatment with greater safety and efficiency as the final goal, similar to other medical applications, robotics has a real potential to fundamentally change microsurgery by combining human strengths with computer and sensor-based technology in an information-driven environment. Still in its early stages, robotic assistance for intraocular microsurgery has been accepted with precaution in the operating room and successfully tested in a limited number of clinical trials. However, owing to its demonstrated capabilities including hand tremor reduction, haptic feedback, steadiness, enhanced dexterity, micrometer-scale accuracy, and others, microsurgery robotics has evolved as a very promising trend in advancing retinal surgery. This paper will analyze the advances in retinal robotic microsurgery, its current drawbacks and limitations, as well as the possible new directions to expand retinal microsurgery to techniques currently beyond human boundaries or infeasible without robotics.

Manifestations of intraocular inflammation over time in patients on brolucizumab for neovascular AMD.

PURPOSE: To describe the adverse events associated with brolucizumab, in particular the sequence of intraocular inflammation (IOI), retinal vasculitis (RV), and/or retinal vascular occlusion (RO). METHODS: This was an unmasked post hoc analysis of the randomized HAWK/HARRIER clinical trials. Patients with neovascular AMD in the brolucizumab arms of the trials were included. IOI-related adverse events reported by study investigators were analyzed to determine early signs and the time course of IOI-related adverse events, using a subgroup of patients with definite/probable IOI cases identified in an independent unmasked post hoc review by an external safety review committee. A limited literature review on IOI following anti-VEGF therapy was also conducted. RESULTS: Among 50 patients with definite/probable IOI cases identified by the safety review committee, 12 had RV or RO adverse events reported by the investigators. For 6 of 12, IOI (other than RV) was reported before RV or RO. The duration from the first IOI adverse event to the first RV or RO adverse event ranged from 16 to 171 days for 5 patients and was 553 days for 1 patient. Four of the 6 patients received ≥ 1 brolucizumab injection on or after the date of the first IOI adverse event and before the first RV or RO adverse event. CONCLUSIONS: IOI may precede RV or RO in some patients treated with brolucizumab.

Randomised controlled trial on robot-assisted versus manual surgery for pucker peeling.

BACKGROUND: The aim was to explore the feasibility and safety of performing common surgical steps in epiretinal membrane (ERM) peeling using the Preceyes Surgical System (PSS). METHODS: In a tertiary centre, 15 pseudophakic patients with an idiopathic ERM were randomised to robot-assistance or manual surgery in a 2:1 ratio. In the robot-assisted group, the following steps were performed using PSS: (1) staining the internal limiting membrane (ILM), (2) removal of the dye, (3) creating an ILM flap, (4) completing the peeling, (5) holding a light pipe and (6) fluid-air exchange. Primary outcome measures were feasibility and safety. Secondary outcome measures were duration, best-corrected visual acuity (BCVA) and central retinal thickness (CRT). Moreover, the distance travelled by the instrument during peeling was assessed using motion tracking software. RESULTS: All steps performed with PSS were feasible with no clinical adverse events or complications. The surgical time was longer in the robot-assisted group (mean 56 min, SD = 12 vs. 24 min, SD = 5). During the study, the duration of robot-assisted surgeries decreased from 72 to 46 min. The distance travelled by the forceps was shorter in the robot-assisted group (mean 403 mm, SD = 186 vs. 550 mm, SD = 134). BCVA and CRT improved equally in both groups. CONCLUSIONS: This is the world's first randomised controlled trial on robotic surgery for ERM. Although more time-consuming, we found that several surgical steps were feasible with assistance of the PSS.

The Role of Intravitreal Corticosteroids in the Treatment of DME: Predictive OCT Biomarkers.

This work aims to summarize predictive biomarkers to guide treatment choice in DME. Intravitreal anti-VEGF is considered the gold standard treatment for centers involving DME, while intravitreal steroid treatment has been established as a second-line treatment in DME. However, more than 1/3 of the patients do not adequately respond to anti-VEGF treatment despite up to 4-weekly injections. Not surprisingly, insufficient response to anti-VEGF therapy has been linked to low-normal VEGF levels in the serum and aqueous humor. These patients may well benefit from an early switch to intravitreal steroid treatment. In these patients, morphological biomarkers visible in OCT may predict treatment response and guide treatment decisions. Namely, the presence of a large amount of retinal and choroidal hyperreflective foci, disruption of the outer retinal layers and other signs of chronicity such as intraretinal cysts extending into the outer retina and a lower choroidal vascular index are all signs suggestive of a favorable treatment response of steroids compared to anti-VEGF. This paper summarizes predictive biomarkers in DME in order to assist individual treatment decisions in DME. These markers will help to identify DME patients who may benefit from primary dexamethasone treatment or an early switch.

Collaborative Ocular Tuberculosis Study Consensus Guidelines on the Management of Tubercular Uveitis-Report 2: Guidelines for Initiating Antitubercular Therapy in Anterior Uveitis, Intermediate Uveitis, Panuveitis, and Retinal Vasculitis.

TOPIC: The Collaborative Ocular Tuberculosis Study (COTS), supported by the International Ocular Inflammation Society, International Uveitis Study Group, and Foster Ocular Immunological Society, set up an international, expert-led consensus project to develop evidence- and experience-based guidelines for the management of tubercular uveitis (TBU). CLINICAL RELEVANCE: The absence of international agreement on the use of antitubercular therapy (ATT) in patients with TBU contributes to a significant heterogeneity in the approach to the management of this condition. METHODS: Consensus statements for the initiation of ATT in TBU were generated using a 2-step modified Delphi technique. In Delphi step 1, a smart web-based survey based on background evidence from published literature was prepared to collect the opinion of 81 international experts on the use of ATT in different clinical scenarios. The survey included 324 questions related to tubercular anterior uveitis (TAU), tubercular intermediate uveitis (TIU), tubercular panuveitis (TPU), and tubercular retinal vasculitis (TRV) administered by the experts, after which the COTS group met in November 2019 for a systematic and critical discussion of the statements in accordance with the second round of the modified Delphi process. RESULTS: Forty-four consensus statements on the initiation of ATT in TAU, TIU, TPU, and TRV were obtained, based on ocular phenotypes suggestive of TBU and corroborative evidence of tuberculosis, provided by several combinations of immunologic and radiologic test results. Experts agreed on initiating ATT in recurrent TAU, TIU, TPU, and active TRV depending on the TB endemicity. In the presence of positive results for any 1 of the immunologic tests along with radiologic features suggestive of past evidence of tuberculosis infection. In patients with a first episode of TAU, consensus to initiate ATT was reached only if both immunologic and radiologic test results were positive. DISCUSSION: The COTS consensus guidelines were generated based on the evidence from published literature, specialists' opinions, and logic construction to address the initiation of ATT in TBU. The guidelines also should inform public policy by adding specific types of TBU to the list of conditions that should be treated as tuberculosis.

A comparison of robotic and manual surgery for internal limiting membrane peeling.

PURPOSE: To compare the Preceyes Surgical Robotic System (Eindhoven, Netherlands) to manual internal limiting membrane (ILM) peeling using the Eyesi surgical simulator (VRmagic, Mannheim, Germany) as the operative platform. METHODS: A comparative study was carried out with surgeons initially performing ILM peeling manually and then with the robot. Twenty-three vitreoretinal surgeons agreed to participate and all consented to the use of their surgical data from the Eyesi surgical simulator. Surgeons were given a 5-min demonstration of the devices and were allowed to practice for 10 min before attempting the membrane peel. Initially, the peel was performed manually and afterwards, this was repeated using the robot-controlled forceps. Surgical simulator outcome measures were compared between approaches. RESULTS: The average time required for the procedure was 5 min for the manual approach and 9 min with the robot (paired t test, p = 0.002). Intraocular instrument movement was reduced by half with the robot. On average 344 mm was required to complete the ILM peeling with the robot compared with 600 mm using the manual approach (paired t test, p = 0.002). There were fewer macular retinal hemorrhages with the robot: 53 with manual surgery, 32 with the robot (Mann-Whitney U test, p = 0.035). Retinal injuries were eliminated with the robot. CONCLUSIONS: Intraocular robotic surgery is still in its infancy and validation work is needed to understand the potential benefits and limitations of emerging technologies. Safety enhancements over current techniques may be possible and could lead to the broader adoption of robotic intraocular surgery in the future.

Efficacy and Safety of Sarilumab for the Treatment of Posterior Segment Noninfectious Uveitis (SARIL-NIU):: The Phase 2 SATURN Study.

PURPOSE: To assess efficacy and safety of sarilumab, a human anti-interleukin-6 receptor antibody, for treatment of posterior segment noninfectious uveitis (NIU). DESIGN: Randomized, double-masked, placebo-controlled, phase 2 study. PARTICIPANTS: Fifty-eight patients (eyes) with noninfectious intermediate, posterior, or panuveitis. METHODS: Eyes received treatment every 2 weeks for 16 weeks with subcutaneous sarilumab 200 mg or placebo. MAIN OUTCOME MEASURES: The primary end point was the proportion of patients with ≥2-step reduction in vitreous haze (VH) on the Miami scale or with a reduction of systemic corticosteroids (prednisolone or equivalent) to a dose of <10 mg/day at week 16. Primary end point was based on VH evaluation by a central reading center. Investigator evaluation of VH was a prespecified, planned secondary analysis. RESULTS: At week 16, proportion of patients taking sarilumab or placebo with ≥2-step reduction in VH or corticosteroid dose <10 mg/day was 46.1% vs. 30.0% (P = 0.2354) based on central reading center assessment of VH and 64.0% vs. 35.0% (P = 0.0372) based on investigator assessment of VH, respectively. In the subgroup of eyes with VH grade ≥2 at baseline, the mean VH reduction from baseline to week 16 was significantly greater with sarilumab vs. placebo regardless of assessment by the central reading center (-2.1 [n = 11] vs. -1.7 [n = 3], respectively; P = 0.0255) or investigator (-2.5 [n = 19] vs. -1.2 [n = 11], respectively; P = 0.0170). The mean best-corrected visual acuity gain from baseline to week 16 was greater with sarilumab vs. placebo in the overall population (8.9 vs. 3.6 letters, respectively; P = 0.0333) and in the subgroup of eyes with central subfield thickness (CST) ≥300 µm at baseline (12.2 [n = 13] vs. 2.1 [n = 7] letters, respectively; P = 0.0517). Corresponding changes in CST were -46.8 vs. +2.6 µm (P = 0.0683) in the overall population and -112.5 [n = 13] vs. -1.8 [n = 6] µm (P = 0.1317) in the subgroup of eyes with CST ≥300 µm at baseline, respectively. The most common ocular adverse events were worsening of uveitis (0 [placebo] and 3 [sarilumab] patients) and retinal infiltrates (1 [placebo] and 2 [sarilumab] patients). CONCLUSIONS: Subcutaneous sarilumab may provide clinical benefits in the management of NIU of the posterior segment, especially in eyes with uveitic macular edema.