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.

STRICT POSTURING WITH OR WITHOUT BILATERAL PATCHING FOR POSTERIOR VITREOUS DETACHMENT-RELATED VITREOUS HEMORRHAGE.

PURPOSE: To determine whether bilateral patching with posturing is superior to posturing alone in visualizing the superior retina in suspected posterior vitreous detachment (PVD)-related vitreous hemorrhage (VH). METHODS: Prospective randomized controlled trial: 80 patients with fundus-obscuring VH due to suspected retinal tear were randomized to strict posturing and bilateral patching overnight (Treatment A, 40 patients) or posturing (Treatment B, 40 patients). PRIMARY OUTCOME: Visualization of ≥4 clock hours superior retina. SECONDARY OUTCOME MEASURES: laser treatment, vitrectomy rate, and retinal detachment within 12 months. RESULTS: Intention-to-treat analysis: In 38/40 (95%) with Treatment A and 32/40 (80%) with Treatment B, the confirmed diagnosis was PVD-related VH. Visibility of the superior retina for all patients: 29/40 (73%) after Treatment A and 21/40 (53%) after Treatment B (P = 0.07). Subgroup analysis for confirmed PVD-related VH; visibility of the superior retina: 29/38 (76%) after Treatment A and 15/32 (47%) after Treatment B (P = 0.01). In subgroup analysis, vitrectomy rate within 12 months was 61% (Treatment A) and 53% (Treatment B) (P = 0.63). Retinal detachment: eight patients after each treatment. CONCLUSION: In patients with suspected PVD-related VH, overnight bilateral patching was not superior to posturing alone in superior retina visualization, but in a post-hoc analysis of patients with confirmed PVD-related VH, bilateral patching was superior.

Robotic-assisted surgery in ophthalmology.

PURPOSE OF REVIEW: Provide an overview of the current landscape of robotics in ophthalmology, including the pros and cons of system designs, the clinical development path, and the likely future direction of the field. RECENT FINDINGS: Robots designed for eye surgery should meet certain basic requirements. Three designs are currently being developed: smart surgical tools such as the steady hand, comanipulation devices and telemanipulators using either a fixed or virtual remote center of motion. Successful human intraocular surgery is being performed using the Preceyes surgical system. Another telemanipulation robot, the da Vinci Surgical System, has been used to perform a pterygium repair in humans and was successful in ex-vivo corneal surgery despite its nonophthalmic design. Apart from Preceyes' BV research platform, none of the currently eye-specific systems has reached a commercial stage. Systems are likely to evolve from robotic assistance during specific procedural steps to semiautonomous surgery, as smart sensors are introduced to enhance the basic functionalities of robotic systems. SUMMARY: Robotics is still in its infancy in ophthalmology but is rapidly reaching a stage wherein it will be introduced into everyday ophthalmic practice. It will most likely be introduced first for demanding vitreo-retinal procedures, followed by anterior segment applications.

INTRAVITREAL VERSUS SUBRETINAL ADMINISTRATION OF RECOMBINANT TISSUE PLASMINOGEN ACTIVATOR COMBINED WITH GAS FOR ACUTE SUBMACULAR HEMORRHAGES DUE TO AGE-RELATED MACULAR DEGENERATION: An Exploratory Prospective Study.

PURPOSE: Current management of submacular hemorrhage (SMH) favors vitrectomy and gas with subretinal administration of recombinant tissue plasminogen activator (rtPA) over mere intravitreal rtPA injections and gas. In this study, we aimed to compare the effectiveness of both treatment modalities to displace submacular blood. METHODS: Twenty-four patients with SMH secondary to age-related macular degeneration were included. The SMH had to exist ≤14 days at time of surgery and SMH thickness had to be between 250 µm and 1,250 µm. Patients were randomized to either intravitreal injections of rtPA, perfluoropropane (C3F8) gas, and bevacizumab (n = 12) or vitrectomy with subretinal rtPA administration, intravitreal C3F8 gas, and bevacizumab (n = 12). The SMH volume change was measured on spectral domain optical coherence tomography postoperatively within a 2.5-mm cylinder centered at the fovea. RESULTS: Median relative volume reduction of subretinal blood at 6 weeks postoperatively was 97% (95% confidence interval: 91-99%) in the intravitreal rtPA group and 100% (95-100%) in the subretinal rtPA group and did not differ significantly between groups (P = 0.56). CONCLUSION: Both treatment modalities effectively displaced SMH in this exploratory clinical trial. To more definitely study the noninferiority of intravitreal rtPA with gas to subretinal rtPA, vitrectomy with gas, a larger clinical trial would be necessary.

Clinical Evaluation of an Instrument-Integrated OCT-Based Distance Sensor for Robotic Vitreoretinal Surgery.

Purpose: To assess the efficacy of an instrument-integrated OCT (iiOCT)-based distance sensor during robotic vitreoretinal surgery using the Preceyes Surgical System (PSS; Preceyes B.V.). Design: Single-center interventional study. Participants: Patients requiring vitreoretinal surgery. Methods: Five patients were enrolled. Standard preoperative OCT images were obtained. After vitrectomy, a predefined set of actions was performed using the iiOCT-based sensor. Images then were processed to assess the signal-to-noise ratio (SNR) at various angles to the retina and at different distances between the instrument tip and the retinal surface. Preoperative and intraoperative OCT images were compared qualitatively and quantitatively. Main Outcomes Measures: The feasibility in performing surgical tasks using the iiOCT-based sensor during vitreoretinal surgery, the SNR when imaging the retina, differences among intraoperative and preoperative OCT images, and characteristics of intraoperative retinal movements detected with the iiOCT-based probe. Results: Surgeons were able to perform all the tasks but one. The PSS was able to maintain a fixed distance. The SNR of the iiOCT-based sensor signal was adequate to determine the distance to the retina and to control the PSS. Analysis of iiOCT-based sensor A-scans identified 3 clearly distinguishable retinal layers, including the inner retinal boundary and the interface at the retinal pigment epithelium-Bruch's membrane. Thickness values differed by less than 5% from that measured by preoperative OCT, indicating its accuracy. The Fourier analysis of iiOCT-based sensor recordings identified anteroposterior retinal movements attributed to heartbeat and respiration. Conclusions: This iiOCT-based sensor was tested successfully and promises reliable use during robot-assisted surgery. An iiOCT-based sensor is a promising step toward OCT-guided robotic retinal surgery.

Human/robotic interaction: vision limits performance in simulated vitreoretinal surgery.

PURPOSE: Compare accuracy and precision in XYZ of stationary and dynamic tasks performed by surgeons with and without the use of a tele-operated robotic micromanipulator in a simulated vitreoretinal environment. The tasks were performed using a surgical microscope or while observing a video monitor. METHOD: Two experienced and two novice surgeons performed tracking and static tasks at a fixed depth with hand-held instruments on a Preceyes Surgical System R0.4. Visualization was through a standard microscope or a video display. The distances between the instrument tip and the targets (in µm) determined tracking errors in accuracy and precision. RESULTS: Using a microscope, dynamic or static accuracy and precision in XY (planar) movements were similar among test subjects. In Z (depth) movements, experience lead to more precision in both dynamic and static tasks (dynamic 35 ± 14 versus 60 ± 37 µm; static 27 ± 8 versus 36 ± 10 µm), and more accuracy in dynamic tasks (58 ± 35 versus 109 ± 79 µm). Robotic assistance improved both precision and accuracy in Z (1-3 ± 1 µm) in both groups. Using a video screen in combination with robotic assistance improved all performance measurements and reduced any differences due to experience. CONCLUSIONS: Robotics increases precision and accuracy, with greater benefit observed in less experienced surgeons. However, human control was a limiting factor in the achieved improvement. A major limitation was visualization of the target surface, in particular in depth. To maximize the benefit of robotic assistance, visualization must be optimized.

A prospective multicentre randomized placebo-controlled superiority trial in patients with suspected bacterial endophthalmitis after cataract surgery on the adjuvant use of intravitreal dexamethasone to intravitreal antibiotics.

PURPOSE: We aimed to determine whether intravitreal dexamethasone as an adjuvant to intravitreal antibiotics is beneficial in the treatment of suspected bacterial endophthalmitis after cataract surgery. METHODS: Randomized, placebo-controlled superiority trial in three tertiary referral centres in the Netherlands. Patients with suspected bacterial endophthalmitis within 6 weeks after cataract surgery were eligible. A diagnostic vitreous biopsy was taken for culture, and patients received intravitreal injections of 400 µg dexamethasone (without preservatives) or placebo, in addition to 0.2 mg vancomycin and 0.05 mg gentamicin. The vancomycin and dexamethasone or placebo injections were repeated once at day 3 or 4. Primary outcome measure was best-corrected visual acuity (BCVA) at 1 year. RESULTS: Between 1 November 2004 and 1 March 2014 (excluding two interruptions totalling 20 months), 324 eligible patients presented. A total of 167 patients (81 dexamethasone, 86 placebo) were available for the intention-to-treat analysis. Biopsies of 114 patients (68%) were culture-positive. Final BCVA did not differ between the dexamethasone and the placebo group (logMAR 0.31 ± 0.58 versus 0.27 ± 0.50; p = 0.90), nor did the number of patients with final vision of no light perception (LP, 7 versus 13). Pain, corneal oedema, the absence of a red fundus reflex on presentation, LP on presentation and culture of virulent pathogens from biopsy were statistically significantly associated with an unfavourable visual outcome. CONCLUSION: Intravitreal dexamethasone without preservatives as an adjuvant to intravitreal antibiotics does not improve visual acuity (VA) in patients treated for suspected bacterial endophthalmitis after cataract surgery.

No evidence for an association of ocular adnexal lymphoma with Chlamydia psittaci in a cohort of patients from the Netherlands.

Extra-nodal marginal zone B cell lymphomas (MZBCLs) of the mucosa-associated lymphoid tissues (MALT) arise at sites of chronic antigenic stimulation due to organ-specific autoimmunity or infections, like Helicobacter pylori-associated chronic gastritis and Borrelia burgdorferi dermatitis. Recently, conflicting data have been published regarding a possible association between Chlamydia psittaci and ocular adnexal MZBCL. In the present study, we analyzed a cohort of ocular adnexal MZBLs from the Netherlands for the presence of C. psittaci DNA. We found no evidence for the presence of C. psittaci DNA in any of the tumor samples studied. Our data do not support a role for C. psittaci in the pathogenesis of ocular adnexal lymphomas in patients from the Netherlands.

Intravitreal ganciclovir in the management of non-AIDS-related human cytomegalovirus retinitis.

OBJECTIVE: To report and evaluate intravitreal ganciclovir injections in non-AIDS patients with human cytomegalovirus (HCMV) retinitis. DESIGN: Retrospective chart review. PARTICIPANTS: Two SLE patients and one patient post chemotherapy for a non Hodgkin's lymphoma presented with myelosuppression and persistent cytomegalovirus retinitis despite systemic ganciclovir therapy. METHODS: Patients were treated with 100 microL of intravitreal ganciclovir (4 mg/dL), initially given weekly. Systemic anti-CMV medication was stopped, and following quiescence, intravitreal injections were tapered and ultimately stopped based on therapeutic response. Patients were followed periodically for signs of recurrence. RESULTS: Intravitreal ganciclovir was well tolerated and led to remission of the retinitis in 2 patients. One patient had persistent smouldering disease and reached quiescence using an intravitreal ganciclovir implant. Fluorescence-activated cell sorting analysis in one patient showed the presence of low CD4 and CD8 while treated with systemic ganciclovir, which improved with intravitreal treatment. In another, the low ratio was maintained against cytomegalovirus-specific antigens. CONCLUSIONS: Intravitreal ganciclovir injections should be considered as a treatment option in selected iatrogenically immunocompromised patients with HCMV retinitis. Responses may vary and will require an adjusted approach to treatment.