Surgical Management of Full-Thickness Macular Holes in Macular Telangiectasia Type 2: A Global Multicenter Study.

PURPOSE: To report on macular hole repair in macular telangiectasia type 2 (MacTel2). DESIGN: Global, multicenter, retrospective case series. PARTICIPANTS: Patients undergoing surgery for MacTel2-associated full-thickness macular hole (MTMH). METHODS: Standardized data collection sheet distributed to all surgeons. MAIN OUTCOME MEASURES: Anatomic closure and visual outcomes of MTMH. RESULTS: Sixty-three surgeries in 47 patients with MTMH were included from 30 surgeons. Mean age was 68.1 years, with 62% female, 72% White, 21% East or South Asian, 2% African American, and 2% Hispanic or Latino. Procedures included 34 internal limiting membrane (ILM) peeling alone, 22 ILM flaps, 5 autologous retinal transplantations (ARTs), 1 retinotomy, and 1 subretinal bleb. For ILM peeling, preoperative visual acuity (VA) was 0.667 ± 0.423 logarithm of the minimum angle of resolution (logMAR). Minimum hole diameter (MHD) was 305.5 ± 159.4 µm (range, 34-573 µm). Sixteen of 34 ILM peels (47%) resulted in MTMH closure. At postoperative month 6, VA was stable at 0.602 ± 0.516 logMAR (P = 0.65). VA improved by at least 2 lines in 43% and at least 4 lines in 24%. For ILM flaps, preoperative VA was 0.878 ± 0.552 logMAR. MHD was 440.8 ± 175.5 µm (range, 97-697 µm), which was significantly larger than for ILM peels (P < 0.01). Twenty of 22 ILM flaps (90%) resulted in MTMH closure, which was significantly higher than for ILM peels (P < 0.01). At postoperative month 6, VA improved to 0.555 ± 0.405 logMAR (P < 0.05). VA improved by at least 2 lines in 56% and at least 4 lines in 28%. For ARTs, preoperative VA was 1.460 ± 0.391 logMAR. MHD was 390.2 ± 203.7 µm (range, 132-687 µm). All 5 ARTs (100%) resulted in MTMH closure. At postoperative month 6, VA was stable at 1.000 ± 0.246 logMAR (P = 0.08). Visual acuity improved at least 2 lines in 25%. CONCLUSIONS: Surgical closure of macular holes improved VA in 57% of MTMHs. Internal limiting membrane flaps achieved better anatomic and functional outcomes than ILM peeling alone. Autologous retinal transplantation may be an option for refractory MTMHs. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Feasibility and Potential for Real-Time 3D Vitreoretinal Surgery Telementoring.

PURPOSE: To demonstrate the potential for real-time, three-dimensional (3D) surgical telementoring to enhance vitreoretinal surgical education. METHODS: The 3D video feed from a high dynamic range surgical camera (NGENUITY) was run through a 4K video capture device (Magewell USB 4K) and set as the video input for a video conferencing application (Zoom). Remote surgical viewing was then performed in two-dimensions (2D) on a computer or in 3D with a virtual reality headset (Oculus Quest 2). RESULTS: Ten surgical cases were successfully live streamed in real time to two separate surgeons in the United States. Specific details of the case were visualized with low latency and interaction with the operating surgeon was possible without affecting the surgical display quality. Excluding the NGENUITY system and personal computers, ancillary equipment costs (video capture card and virtual reality headset) were kept to below $1,000. CONCLUSION: Our study demonstrates that 3D surgical video streaming can be achieved in real time with minimal latency through the use of low-cost video capture equipment and video conferencing/streaming software. The use of this technology gives educators the ability to mentor trainees without the traditional geographic and physical constraints of in-person surgical viewing.

FLUIDIC PERFORMANCE OF A DUAL-ACTION VITRECTOMY PROBE COMPARED WITH A SINGLE-ACTION PROBE.

PURPOSE: To assess flow rates, nearfield effects, and traction of a dual-cutting 20,000 cpm vitrectomy probe (HYPERVIT, Alcon) versus a single-cutting 10,000 cpm probe (Advanced ULTRAVIT, Alcon). METHODS: Flow rates were evaluated for 25+ and 27+ gauge probes using balanced salt solution or porcine cadaver vitreous (biased open, 50/50, and biased closed duty cycles). Probes were suspended in an open beaker, and flow rates were calculated using a precision balance. Nearfield effects and flow pulsatility were assessed using a validated simulation model based on experimental microparticle image velocimetry. Traction was assessed by attaching vitreous to a cantilever beam and measuring the deflection of the beam. RESULTS: For HYPERVIT probes, aqueous flow rates were similar across all cutting rates. Vitreous flow rates increased with increasing cutting rates. At maximum cutting rates, aqueous flow was 62%-67% greater (25+) and 63% greater (27+) with HYPERVIT versus Advanced ULTRAVIT ( P < 0.05); vitreous flow was 44%-47% greater (25+) and 26%-32% greater (27+) with HYPERVIT versus Advanced ULTRAVIT ( P < 0.05). Nearfield effects were reduced, and peak traction forces were significantly lower for HYPERVIT versus Advanced ULTRAVIT ( P < 0.05). CONCLUSION: Significantly greater aspiration flow, reduced nearfield effects, and reduced traction were observed with dual-action versus single-action probes.

Autologous Retinal Transplantation for Primary and Refractory Macular Holes and Macular Hole Retinal Detachments: The Global Consortium.

PURPOSE: To report the anatomic and functional outcomes of autologous retinal transplantation (ART). DESIGN: Multicenter, retrospective, interventional, consecutive case series. PARTICIPANTS: One hundred thirty eyes of 130 patients undergoing ART for the repair of primary and refractory macular holes (MHs), as well as combined MH-rhegmatogenous retinal detachment (MH-RRD), between January 2017 and December 2019. METHODS: All patients underwent pars plana vitrectomy and ART, with surgeon modification of intraoperative variables. A large array of preoperative, intraoperative, and postoperative data was collected. Two masked reviewers graded OCT images. Multivariate statistical analysis and subgroup analysis were performed. MAIN OUTCOME MEASURES: Macular hole closure rate, visual acuity (VA), external limiting membrane and ellipsoid zone (EZ) band integrity, and alignment of neurosensory layers (ANL) on OCT. RESULTS: One hundred thirty ART surgeries were performed by 33 vitreoretinal surgeons worldwide. Patient demographics were: mean age of 63 ± 6.3 years, 58% female, 41% White, 23% Black, 19% Asian, and 17% Latino. Preoperative VA was 1.37 ± 0.12 logarithm of the minimum angle of resolution (logMAR; Snellen equivalent, approximately 20/500), which improved significantly to 1.05 ± 0.09 logMAR (Snellen equivalent, approximately 20/225; P < 0.001) after surgery (mean follow-up, 8.6 ± 0.8 months). Autologous retinal transplantation was performed for primary MH repair in 27% of patients (n = 35), for refractory MH in 58% of patients (n = 76; mean number of previous surgeries, 1.6 ± 0.2), and for MH-RRD in 15% of patients (n = 19). Mean maximum MH diameter was 1470 ± 160 µm, mean minimum diameter was 840 ± 94 µm, and mean axial length was 24.6 ± 3.2 mm. Overall, 89% of MHs closed (78.5% complete; 10% small eccentric defect), with a 95% closure rate in MH-RRD (68.4% complete; 26.3% small eccentric defect). Visual acuity improved by at least 3 lines in 43% of eyes and by at least 5 lines in 29% of eyes. Reconstitution of the EZ (P = 0.02) and ANL (P = 0.01) on OCT were associated with better final VA. Five cases of ART graft dislocation (3.8%), 5 cases of postoperative retinal detachment (3.8%), and 1 case of endophthalmitis (0.77%) occurred. CONCLUSIONS: In this global experience, patients undergoing ART for large primary and refractory MHs and MH-RRDs achieved good anatomic and functional outcomes, with low complication rates despite complex surgical pathologic features.

Clinical comparison of 27-gauge and 23-gauge instruments on the outcomes of pars plana vitrectomy surgery for the treatment of vitreoretinal diseases.

PURPOSE OF REVIEW: To compare outcomes of 27-gauge and 23-gauge pars plana vitrectomy (PPV) for treatment of vitreoretinal diseases. RECENT FINDINGS: Sixty-eight patients undergoing microincisional PPV for treatment of vitreoretinal diseases were randomized 1 : 1 to 27-gauge or 23-gauge surgery with a 7500 cuts-per-minute vitrectomy probe. The most common reasons for vitrectomy were epiretinal membrane (49%) and vitreous hemorrhage (24%). Mean ±â€Šstandard deviation (SD) changes from immediate preoperative to immediate postoperative intraocular pressure were -0.40 ±â€Š6.60 mmHg in the 27-gauge and -3.05 ±â€Š7.64 mmHg in the 23-gauge group (adjusted mean difference 2.42 mmHg, 95% lower confidence limit 0.64, P = 0.013), but these changes were not associated with primary reason for vitrectomy (P = 0.065). Mean ±â€ŠSD conjunctival edema grades in the 27-gauge and 23-gauge groups 1 week after surgery were 0.02 ±â€Š0.124 and 0.10 ±â€Š0.246, respectively (least squares mean difference -0.09, 95% upper confidence limit -0.03, P = 0.004), and were 0.01 ±â€Š0.122 and 0.12 ±â€Š0.338, respectively, at the probe incision site. Conjunctival edema grades were similar in both groups at 1 and 3 months. Mean ±â€ŠSD pain ratings on postoperative day 1 - an indicator of patient comfort - were similar in the two groups. SUMMARY: Smaller diameter vitrectomy instruments are associated with smaller reductions in immediate postoperative intraocular pressure.

Autologous Retinal Transplant for Refractory Macular Holes: Multicenter International Collaborative Study Group.

PURPOSE: To report the structural and functional outcomes of autologous neurosensory retinal transplant for closure of refractory large macular holes (MHs). DESIGN: Multicenter, retrospective, consecutive case series. PARTICIPANTS: A total of 41 eyes of 41 patients with a full-thickness MH refractory to prior vitrectomy with internal limiting membrane (ILM) peel and tamponade. METHODS: All patients underwent pars plana vitrectomy, autologous neurosensory retinal transplant with gas, silicone oil tamponade, or short-term perfluoro-n-octane heavy-liquid tamponade. All patients had at least 6 months' follow-up. MAIN OUTCOME MEASURES: Anatomic closure of MH, change in ellipsoid zone (EZ) and external limiting membrane (ELM) defect on OCT, visual acuity (VA) recovery, and surgical complications were analyzed. RESULTS: Mean number of prior surgeries was 1.5±0.94 (range, 1-3), and patients were followed for a mean of 11.1±7.7 months (range, 6-36 months). Complete anatomic closure of MH by OCT was achieved in 36 of 41 eyes (87.8%). Mean corrected VA (logarithm of the minimum angle of resolution [logMAR]) improved (P = 0.03) from 1.11±0.66 (range, 0.48-3) to 1.03±0.51 (range, 0.1-2) at the last postoperative visit. The VA improved (≥0.3 logMAR units) in 15 eyes (36.6%), was stable in 17 eyes (41.5%), and worsened in 9 eyes (21.9%). Among eyes with anatomic closure, VA improved in 52.3% and worsened in 13.8%, whereas in those without closure, VA worsened in 40% and improved in none. Mean preoperative largest basal diameter was 1468.1±656.4 µm (range, 621-2600 µm), and mean inner-opening diameter was 825±422.5 µm (range, 336-1649 µm). Mean preoperative EZ defect was 1777.3±513.8 µm (range, 963-2808 µm), which decreased to 1370±556.9 µm (range, 288-2000 µm) at final follow-up (P = 0.007). Mean preoperative ELM was 1681.5±429 µm (range, 1172-2606 µm), which decreased to 1408.5±571.2 µm (range, 200-2000 µm) at final follow-up (P = 0.017). Major postoperative complications were retinal detachment (n = 1) and vitreous hemorrhage (n = 1). There were no cases of proliferative vitreoretinopathy, endophthalmitis, suprachoroidal hemorrhage, or choroidal neovascularization. CONCLUSIONS: The autologous retinal transplant technique offers a high degree of anatomic success and proved safe in this initial experience for closure of refractory MHs.

Vancomycin-Associated Hemorrhagic Occlusive Retinal Vasculitis: Clinical Characteristics of 36 Eyes.

PURPOSE: To expand understanding of presentation, diagnosis, and outcomes of hemorrhagic occlusive retinal vasculitis (HORV). DESIGN: Retrospective case series. PARTICIPANTS: Thirty-six eyes of 23 patients. METHODS: The American Society of Cataract and Refractive Surgery (ASCRS) and the American Society of Retina Specialists (ASRS) formed a joint task force to define clinical characteristics of HORV and to study its prevalence, cause, treatment, and outcomes. An online registry was established on both societies' web sites. Surveys were e-mailed to members of both societies soliciting cases of suspected HORV. A literature search was performed to uncover additional cases. MAIN OUTCOME MEASURES: Historical data including intraoperative characteristics, images, treatment regimens, and visual and anatomic outcomes. RESULTS: Characteristic findings of HORV included unremarkable postoperative day 1 undilated examination, delayed-onset painless vision loss, mild anterior chamber and vitreous inflammation, sectoral retinal hemorrhages in areas of ischemia, and predilection for venules and peripheral involvement. Based on predetermined diagnostic criteria, 36 eyes of 23 patients were diagnosed with HORV. All eyes received intraocular vancomycin via intracameral bolus (33/36), via intravitreal injection (1/36), or through the irrigation bottle (2/36). Patients sought treatment with HORV 1 to 21 days after surgery or intravitreal injection. Visual results usually were poor: 22 of 36 eyes (61%) had 20/200 or worse visual acuity and 8 of 36 eyes (22%) had no light perception (NLP). Neovascular glaucoma developed in 20 of 36 eyes (56%). Seven eyes received additional intravitreal vancomycin after surgery; 5 of these 7 eyes had NLP visual acuity at the most recent examination. Three eyes received intravitreal corticosteroids and had final visual acuities of 20/40, 20/70, and hand movements. CONCLUSIONS: Hemorrhagic occlusive retinal vasculitis is a rare, potentially devastating condition that can develop after cataract surgery or intraocular injection. All cases in this series were associated with intraocular vancomycin. Disease course and findings suggest that HORV is caused by a delayed hypersensitivity reaction to vancomycin. Early treatment with corticosteroids likely is beneficial. Subsequently, anti-vascular endothelial growth factor injections and panretinal photocoagulation are important to prevent neovascular glaucoma, a common complication. Avoidance of additional intravitreal vancomycin is recommended if HORV is suspected.

25-gauge pars plana vitrectomy with medium-term postoperative perfluoro-n-octane for the repair of giant retinal tears.

PURPOSE: The purpose of this study was to describe the treatment of giant retinal tears (GRTs) with 25-gauge pars plana vitrectomy (PPV) and medium-term postoperative perfluoro-n-octane (MT-PFO). METHODS: The study was a retrospective interventional case series of consecutive patients with GRTs treated with 25-gauge PPV and postoperative MT-PFO for a period of 2-3 weeks. A second, staged procedure was performed in all patients for PFO removal. RESULTS: Twenty-three eyes of 22 patients were studied, with a mean follow-up of 33.04 ± 19.74 months. Successful reattachment was achieved in 91.3 % of eyes (21/23) after MT-PFO. Retinal re-detachment occurred in five eyes, which was caused by proliferative vitreoretinopathy. Additional complications included cataract progression (n = 10), foreign body response (30.4 %, 7/23), and transient intraocular pressure (IOP) elevation (8/23, 34.8 %). Transient IOP elevation was associated with worse visual outcome (p = 0.01). CONCLUSIONS: MT-PFO was found to be an effective and safe technique for operative management of GRTs. In the majority of patients, retinas remained attached without further surgical intervention. Cataract progression, intraocular inflammation, and associated increased intraocular pressure are potential complications of MT-PFO.

Foreign body response within postoperative perfluoro-N-octane for retinal detachment repair: clinical features, grading system, and histopathology.

PURPOSE: To describe the clinical and histopathologic characteristics of inflammatory deposits occurring within intermediate duration postoperative perfluoro-n-octane (PFO) for inferior retinal detachment repair. METHODS: Prospective interventional case series of consecutive patients with inferior retinal detachment treated with intermediate duration postoperative vitreous cavity PFO endotamponade were analyzed by ophthalmoscopy for the presence of inflammation and white deposits. Ten consecutive samples developing white deposits were analyzed microscopically. Clinical variables were analyzed. RESULTS: One hundred and eighty-one eyes of 181 patients were included (mean age = 52.4 ± 14 years; mean follow-up = 29.7 ± 14 months). Fifty of 181 patients (28%) developed a characteristic foreign body response with abundant white deposits within indwelling PFO. Ten consecutive samples analyzed histologically contained abundant macrophages, the absence of additional inflammatory cells, and intracytoplasmic optically lucent inclusions. Foreign body response was associated with longer duration of PFO (P = 0.003). Perfluoro-n-octane foreign body response was not associated with age (P = 0.136), ethnicity (P = 0.101), visual outcome (P = 0.157), or persistent intraocular pressure elevation (P = 0.381). CONCLUSION: A stereotypical foreign body response occurs in ∼ 30% of patients with postoperative vitreous cavity PFO and becomes clinically apparent at 7 days to 10 days after initial placement for rhegmatogenous retinal detachment repair. The response consists almost exclusively of macrophages and does not seem to be related to either long-term intraocular pressure elevation or visual outcome. The response may be related to the duration of indwelling PFO and may limit visualization of the retina during PFO removal.

Anatomical and visual outcomes after two-port pars plana vitrectomy reoperation under silicone oil for epimacular membrane or recurrent retinal detachment.

PURPOSE: To describe the anatomical and visual outcomes in a series of patients undergoing two-port pars plana vitrectomy reoperation under silicone oil for recurrent retinal detachment (RD) due to proliferative vitreoretinopathy or epimacular membrane (EMM) after RD repair. METHODS: This study is a prospective, consecutive, interventional case series of patients presenting with recurrent RD or EMM under silicone oil. Two-port 25-gauge pars plana vitrectomy reoperation without an infusion port was performed in all cases. RESULTS: Thirty-nine patients were included. Reoperation pathology included recurrent RD with proliferative vitreoretinopathy (n = 33) and EMM alone (n = 6). The mean number of previous retinal surgeries was 2.4 ± 1.1 (range, 1-5). The mean overall follow-up was 24 ± 3.7 months. The mean visual acuity change from baseline at final follow-up was an improvement of 0.74 ± 0.63. Macular reattachment was achieved in 29 of 33 patients with RD, and EMMs were successfully removed in all patients. CONCLUSION: Two-port pars plana vitrectomy reoperation is an efficacious method for repair of consecutive RD due to proliferative vitreoretinopathy or EMM in patients with previous RD repair with silicone oil. Significant visual improvement with a low complication rate may be achieved in patients with advanced proliferative vitreoretinopathy or EMM under silicone oil.

Delayed onset inner nuclear layer cystic changes following internal limiting membrane removal for epimacular membrane.

PURPOSE: To report the rare occurrence of new inner nuclear layer cystic spaces occurring in eyes treated with pars plana vitrectomy (PPV) and internal limiting membrane (ILM) removal for idiopathic epimacular membrane (EMM). MATERIALS AND METHODS: Consecutive patients with EMM without preoperative retinal cystic changes undergoing PPV with ILM peeling were retrospectively evaluated. Patients developing a characteristic inner nuclear layer cystic change were analyzed. RESULTS: Inner nuclear layer cystic changes appeared in eight of 768 (1.04 %) eyes at a mean postoperative time period of 3.2 ± 0.89 months. No leakage or pooling was demonstrated on postoperative fluorescein angiography. Morphologic characteristics included vertically elongated hyporeflectant spaces within the inner nuclear layer on spectral domain optical coherence tomography (SD-OCT). CONCLUSIONS: A minority of patients undergoing PPV with ILM peeling develop new, delayed onset, postoperative inner nuclear layer cystic spaces with a characteristic SD-OCT appearance and no evidence of angiographic leakage.

Comparison of observation, intravitreal bevacizumab, or pars plana vitrectomy for non-proliferative type 2 idiopathic macular telangiectasia.

PURPOSE: To compare visual and anatomic outcomes in eyes with type 2 idiopathic macular telangiectasia (Mactel) treated with either intravitreal bevacizumab (IVB), observation, or pars plana vitrectomy (PPV) with internal limiting membrane removal. METHODS: Retrospective, consecutive, interventional case series of phakic patients with Mactel. Best-corrected Snellen visual acuity (BCVA) and complete ophthalmic exam was obtained prior to treatment and at subsequent 3-month intervals for a minimum of 6 months. Fluorescein angiographic and spectral-domain optical coherence tomography features were examined, and compared to BCVA at treatment initiation and follow-up. RESULTS: Fifty-six eyes of 28 patients were evaluated. Mean age was 65 ± 12 years, and mean follow-up was 24 ± 13 months. Patients were treated with either observation (n = 33), IVB (n = 15), or PPV (n = 8). Mean number of treatments for the IVB group was 2.5 ± 3.5 intravitreal injections. No significant differences in BCVA change were observed between treatment groups via one-way ANOVA (p = 0.49). Presence of inner retinal cysts was not correlated to BCVA (p > 0.05). Discontinuous outer nuclear layer was significantly related to worse initial and final vision, but not to BCVA change. CONCLUSION: IVB and PPV with ILM removal appear ineffective in improving visual outcome in eyes with non-proliferative Mactel. SD-OCT evidence of disrupted foveal outer nuclear layer is related to decreased BCVA, but not related to BCVA change following treatment.

Pars plana vitrectomy with medium-term postoperative perfluoro-N-octane for recurrent inferior retinal detachment complicated by advanced proliferative vitreoretinopathy.

PURPOSE: To describe a series of patients with recurrent inferior retinal detachment complicated by proliferative vitreoretinopathy (PVR) treated with pars plana vitrectomy and postoperative perfluoro-n-octane (PFO). METHODS: Consecutive patients with recurrent inferior retinal detachment and Grade C PVR were prospectively treated with 25-gauge pars plana vitrectomy and postoperative "medium-term" PFO for 2- to 3-week duration. All patients had subsequent PFO removal in a planned staged procedure. RESULTS: Forty-four eyes of 44 patients were included. Mean follow-up time was 30.71 ± 12.92 months. Successful reattachment was achieved in 86% of eyes (38/44). Reattachment rates were statistically equivalent between eyes with and without previous scleral buckle. Reasons for redetachment were recurrent inferior PVR (four of six) and new superior break without PVR (two of six). Additional complications observed were cataract progression requiring surgery (42%), persistent intraocular pressure elevation (36%), and transient inflammation (32%). Macula-off status (P = 0.02) and persistent intraocular pressure elevation (P = 0.02) were factors associated with worse visual outcome. CONCLUSION: Medium-term PFO was found to be an efficacious technique for operative management of recurrent inferior retinal detachments complicated by Grade C PVR. The method of primary repair (scleral buckle vs. pars plana vitrectomy) did not affect reattachment rates. Transient inflammation and intraocular pressure elevation are potential complications associated with this technique. Persistent intraocular pressure elevation was associated with worse visual outcome.

Vitrectomy fluidics.

The goal of all vitreous surgery is to perform the desired intraoperative intervention with minimum collateral damage in the most efficient way possible. An understanding of the principles of fluidics is of importance to all vitreoretinal surgeons to achieve these aims. Advances in technology mean that surgeons are being given increasing choice in the settings they are able to select for surgery. Manufacturers are marketing systems with aspiration driven by peristaltic, Venturi and hybrid pumps. Increasingly fast cut rates are offered with optimised, and in some cases surgeon-controlled, duty cycles. Function-specific cutters are becoming available and narrow-gauge instrumentation is evolving to meet surgeon demands with higher achievable flow rates. In parallel with the developments in outflow technology, infusion systems are advancing with lowering flow resistance and intraocular pressure control to improve fluidic stability during surgery. This review discusses the important aspects of fluidic technology so that surgeons can select the optimum machine parameters to carry out safe and effective surgery.

Barriers and facilitators to walking and physical activity among American Indian elders.

INTRODUCTION: Physical inactivity is common among older American Indians. Several barriers impede the establishment and maintenance of routine exercise. We examined personal and built-environment barriers and facilitators to walking and physical activity and their relationship with health-related quality of life in American Indian elders. METHODS: We used descriptive statistics to report barriers and facilitators to walking and physical activity among a sample of 75 American Indians aged 50 to 74 years. Pearson correlation coefficients were used to examine the relationship between health-related quality of life and barriers to walking and physical activity after adjusting for caloric expenditure and total frequency of all exercise activities. RESULTS: Lack of willpower was the most commonly reported barrier. Elders were more likely to report personal as opposed to built-environment reasons for physical inactivity. Better health and being closer to interesting places were common walking facilitators. Health-related quality of life was inversely related to physical activity barriers, and poor mental health quality of life was more strongly associated with total barriers than poor physical health. CONCLUSION: We identified a variety of barriers and facilitators that may influence walking and physical activity among American Indian elders. More research is needed to determine if interventions to reduce barriers and promote facilitators can lead to objective, functional health outcomes.

Chemical standards in ion mobility spectrometry.

In ion mobility spectrometry (IMS), reduced mobility values (K(0)) are used as a qualitative measure of gas phase ions, and are reported in the literature as absolute values. Unfortunately, these values do not always match with those collected in the field. One reason for this discrepancy is that the buffer gas may be contaminated with moisture or other volatile compounds. In this study, the effect of moisture and organic contaminants in the buffer gas on the mobility of IMS standards and analytes was investigated for the first time using IMS directly coupled to mass spectrometry. 2,4-Dimethylpyridine, 2,6-di-tert-butylpyridine (DTBP), and tetrabutylammonium, tetrapropylammonium, tetraethylammonium, and tetramethylammonium chlorides were used as chemical standards. In general, the mobility of IMS standard product ions was not affected by small amounts of contamination while the mobilities of many analytes were affected. In the presence of contaminants in the buffer gas, the mobility of analyte ions is often decreased by forming ion-molecule clusters with the contaminant. To ensure the measurement of accurate reduced mobility values, two IMS standards are required: an instrument and a mobility standard. An instrument standard is not affected by contaminants in the buffer gas, and provides an accurate measurement of the instrumental parameters, such as voltage, drift length, pressure, and temperature. The mobility standard behaves like an analyte ion in that the compound's mobility is affected by low levels of contamination in the buffer gas. Prudent use of both of these standards can lead to improved measurement of accurate reduced mobility values.

Clinical-grade stem cell-derived retinal pigment epithelium patch rescues retinal degeneration in rodents and pigs.

Considerable progress has been made in testing stem cell-derived retinal pigment epithelium (RPE) as a potential therapy for age-related macular degeneration (AMD). However, the recent reports of oncogenic mutations in induced pluripotent stem cells (iPSCs) underlie the need for robust manufacturing and functional validation of clinical-grade iPSC-derived RPE before transplantation. Here, we developed oncogenic mutation-free clinical-grade iPSCs from three AMD patients and differentiated them into clinical-grade iPSC-RPE patches on biodegradable scaffolds. Functional validation of clinical-grade iPSC-RPE patches revealed specific features that distinguished transplantable from nontransplantable patches. Compared to RPE cells in suspension, our biodegradable scaffold approach improved integration and functionality of RPE patches in rats and in a porcine laser-induced RPE injury model that mimics AMD-like eye conditions. Our results suggest that the in vitro and in vivo preclinical functional validation of iPSC-RPE patches developed here might ultimately be useful for evaluation and optimization of autologous iPSC-based therapies.

Efficacy and Safety of Intravitreal Conbercept, Ranibizumab, and Triamcinolone on 23-Gauge Vitrectomy for Patients with Proliferative Diabetic Retinopathy.

INTRODUCTION: To compare the effect and safety of intravitreal conbercept (IVC), intravitreal ranibizumab (IVR), or intravitreal triamcinolone acetonide (IVTA) injection on 23-gauge (23-G) pars plana vitrectomy (PPV) for proliferative diabetic retinopathy (PDR). METHODS: Fifty patients (60 eyes) of varying degrees of PDR were randomly grouped into 3 groups (1 : 1 : 1) (n = 20 in each group). The 23-G PPV was performed with intravitreal conbercept or ranibizumab injection 3-7 days before surgery or intravitreal TA injection during surgery. The experiment was randomized controlled, with a noninferiority limit of five letters. Main outcome measures included BCVA, operation time, incidence of iatrogenic retinal breaks, endodiathermy rate, and silicone oil tamponade. RESULTS: At 6 months after surgery, there were no significant differences of BCVA improvements, operation time, incidence of iatrogenic retinal breaks, endodiathermy rate, silicone oil tamponade, vitreous clear-up time, and the incidence of intraoperative bleeding between the IVC and IVR groups (all P values ≥ 0.05), but they were significantly different from the IVTA group (all P values < 0.05). IOP increases did not show significant differences between the IVC and IVR groups, but both were significantly different with the IVTA group. More patients had higher postoperative IOP in the IVTA group. CONCLUSIONS: The intravitreal injection of conbercept, ranibizumab, or TA for PDR had a significant different effect on outcomes of 23-G PPV surgery. Conbercept and ranibizumab can reduce difficulty of the operation, improve the success rate of PPV surgery, and decrease the incidence of postoperative complications.