INTRAOPERATIVE BLEB BEHAVIOR IN SUBRETINAL GENE AUGMENTATION THERAPY FOR INHERITED RETINAL DISEASES.

Inherited retinal diseases (IRDs) are a group of diseases whose common landmark is progressive photoreceptor loss. The development of gene‐specific therapies for IRDs is hampered by their wide genetic heterogeneity. Mitochondrial dysfunction is proving to constitute one of the key pathogenic events in IRDs; hence, approaches that enhance mitochondrial activities have a promising therapeutic potential for these conditions. We previously reported that miR‐181a/b downregulation boosts mitochondrial turnover in models of primary retinal mitochondrial diseases. Here, we show that miR‐181a/b silencing has a beneficial effect also in IRDs. In particular, the injection in the subretinal space of an adeno‐associated viral vector (AAV) that harbors a miR‐181a/b inhibitor (sponge) sequence (AAV2/8‐GFP‐Sponge‐miR‐181a/b) improves retinal morphology and visual function both in models of autosomal dominant (RHO‐P347S) and of autosomal recessive (rd10) retinitis pigmentosa. Moreover, we demonstrate that miR‐181a/b downregulation modulates the level of the mitochondrial fission‐related protein Drp1 and rescues the mitochondrial fragmentation in RHO‐P347S photoreceptors. Overall, these data support the potential use of miR‐181a/b downregulation as an innovative mutation‐independent therapeutic strategy for IRDs, which can be effective both to delay disease progression and to aid gene‐specific therapeutic approaches.

Retinal damage has been associated with increased injection pressure during subretinal gene therapy delivery in various animal models, yet there are no human clinical data regarding the pressures required to initiate and propagate subretinal blebs. This study characterized the intraoperative pressure levels for subretinal gene therapy delivery across eight retinal conditions. A total of 116 patients with retinal degenerative diseases have been treated with subretinal gene therapy at OHSU-Casey Eye Institute as of June 2020; seventy patients (60.3%) were treated using a pneumatic-assisted subretinal delivery system. All retinal blebs were performed using a 41-gauge injection cannula, and use of a balanced salt solution (BSS) "pre-bleb" prior to gene therapy delivery was performed at the discretion of the surgeon. Patient age and intraoperative data for BSS and vector injections were analyzed in a masked fashion for all patients who received pneumatic-assisted subretinal gene therapy. The median age of the patients was 35 years (range 4-70). No significant differences in injection pressures were found across the eight retinal conditions. In this study, patient age was shown to affect maximum injection pressures required for bleb propagation, and the relationship between age and pressure varied based on retinal condition. These data have important implications in optimizing surgical protocols for subretinal injections.

To estimate in humans, in vivo, drug retention in the subretinal space following either 1- or 2-step subretinal injection (SRI). A single-masked, randomized, controlled trial. Patients presenting with submacular hemorrhage secondary to age-related macular degeneration were randomly allocated to receive subretinal tissue plasminogen activator (50 µg in 0.1 mL) with sodium fluorescein (10 µg in 0.1 mL) as an optical label either as a 1-step (n = 6) procedure, in which the drug defines the subretinal space, or as a 2-step (n = 6) procedure, in which balanced salt solution is first used to define the subretinal space, following pars plana vitrectomy. All patients underwent air-for-fluid exchange at the completion of surgery with subsequent 20% sulfahexafluoride gas and bevacizumab injection. Reflux of subretinally injected drug was calculated by performing fluorophotometry on the fluid collected at the end of air-for-fluid exchange. Patients received intravitreal anti-VEGF at 4-weekly intervals to the final follow-up at 12 weeks. The primary outcome measure was the proportion of drug reflux. Secondary outcomes included duration of surgery, change in visual acuity (VA), final VA, final foveal thickness, and change in foveal thickness. To determine our fluorophotometric technique's applicability to gene and cell therapy, real-time quantitative polymerase chain reaction was employed to determine adeno-associated viral (AAV) yields following exposure to 0.1 mg/mL sodium fluorescein and its effects on retinal progenitor cells (RPCs) was assessed using a cell viability assay. Mean reflux was 4.8% ± 3.1% (mean ± SEM, range 0.4%-19.5%) for 1-step SRI and 3.9% ± 0.9% (range 1.7%-5.3%) for 2-step SRI (no significant difference in means; P = .0155 for the difference in variance). There was no significant difference in the duration of surgery (26.8 ± 1.2 minutes vs 30 ± 2.7 minutes), final VA (1.1 ± 0.26 [Snellen 20/252] vs 1.1 ± 0.32 [Snellen 20/252] logMAR), change in BCVA (-0.45 ± 0.27 vs -0.27 ± 0.23 logMAR) or foveal thickness (139.2 ± 33.2 µm vs 129.8 ± 21.1 µm). Quantitative polymerase chain reaction confirmed that AAV titers are not affected by 0.1 mg/mL sodium fluorescein in vitro, and viability assays suggest that it does not adversely affect RPC viability. This study demonstrates that drug loss following SRI ranged from 0.4% to 19.8% (mean 4.3%). There is no significant difference between 1-step and 2-step SRI in the mean proportion of drug reflux, duration of surgery, change in neural retinal thickness, or change in BCVA. However, there is a significantly greater variability in reflux for 1-step injection compared to 2-step injection. AAV yields are not affected by 0.1 mg/mL sodium fluorescein, nor is RPC viability. These data suggest that sodium fluorescein may be an appropriate means of tracking subretinal AAV gene therapy and retinal cell therapy quantitatively and that the 2-step SRI approach is preferable to 1-step SRI to ensure consistency in drug delivery.

To evaluate retinal thickness using spectral-domain optical coherence tomography (SD-OCT) with reduced speckle noise in eyes with polypoidal choroidal vasculopathy (PCV) compared to those with normal eyes and those with central serous chorioretinopathy (CSC). We retrospectively reviewed cases of foveal serous retinal detachment in 36 eyes of 36 patients with active CSC and 23 eyes of 23 patients with active PCV, and 44 eyes of 44 normal subjects. Patients were examined using SD-OCT with reduced speckle noise, and the thickness of the outer nuclear layer (ONL), photoreceptor inner segment (IS), and photoreceptor outer segment (OS) were measured. The ONL and IS were thicker in normal eyes than in eyes with CSC or PCV (P < 0.001). The OS was significantly less thick in eyes with PCV than in normal eyes (P < 0.001), whereas there was no significant difference between eyes with CSC and normal eyes. The thickness of IS and OS in eyes with PCV was related to fibrin or hemorrhage being present in the subretinal space. In eyes with PCV, best-corrected visual acuity at baseline correlated with IS thickness (P = 0.023). Thinning of each photoreceptor layer was observed in the eyes of PCV patients as compared to that observed in the case of normal individuals. The differentiating factors between PCV and CSC, observed using SD-OCT, include the thinning of the OS in eyes with PCV, which makes SD-OCT helpful in differentiating PCV from CSC. More severe photoreceptor alterations were seen in PCV, because fibrin and hemorrhage were present in the subretinal space, which correlated with poorer vision.

PurposeTo evaluate the safety and efficacy of subretinal gene therapy using AGTC-501 (rAAV2tYF-GRK1-RPGR) in male participants with X-linked retinitis pigmentosa (XLRP). DesignPhase 1/2, open-label, dose-escalation study. MethodsSetting: Four centers in the United States. Patient or Study Population: Twenty-nine males with XLRP and confirmed pathogenic RPGR variants. Mean age was 31.6 years (range 15-55). Intervention: Subretinal injection of AGTC-501 at doses ranging from 2.48 × 1010 to 1.99 × 1012 vg/eye administered in one eye per participant. Subretinal injection sites initially targeted the peripheral retina and then transitioned to the macula with successive cohorts. Main Outcome Measures: Treatment-emergent adverse events (TEAEs), serious adverse events (SAEs), laboratory parameters, and immunological responses. Efficacy was evaluated by mesopic microperimetry mean sensitivity. ResultsAll 29 participants experienced ≥1 TEAE. Eleven (38%) experienced ≥1 grade 3 TEAE. Six (21%) experienced ≥1 ocular SAE related to AGTC-501, including retinal detachment (n=4), subcapsular cataract (n=1), and glaucoma (n=1). Two (6.9%) experienced non-ocular treatment-emergent SAEs. Immunological findings did not indicate safety concerns. Three of 4 participants at the highest dose exhibited concerning retinal pigment epithelial changes. Half the participants at the highest tolerated dose (6.8 × 1011vg/eye) maintained ≥7 dB improvement in ≥5 loci at 24 months. ConclusionsSubretinal AGTC-501 was generally well-tolerated. Despite all participants experiencing at least one TEAE, most of these events were mild in nature, exhibited complete resolution, and were associated with the subretinal injection procedure itself rather than the study agent. The highest dose exhibited an unfavorable risk-benefit profile due to the development of RPE changes. Although this group had the highest improvement in retinal sensitivity, our team has decided not to continue this dose in future clinical trials. Preliminary efficacy was observed at the maximum tolerated dose. Further studies are warranted to assess long-term safety and efficacy of AGTC-501 for XLRP treatment.

PurposeThe purpose of this study was to evaluate whether clinical grade recombinant adeno-associated virus serotype 8 (rAAV8) leads to increased appearance of hyper-reflective foci (HRF) in the retina of non-human primates (NHPs) following subretinal gene therapy injection.MethodsDifferent doses of rAAV8 vector (rAAV8. human phosphodiesterase 6A subunit (hPDE6A) at low dose: 1 × 1011 vector genomes (vg), medium dose: 5 × 1011 vg, or high dose: 1 × 1012 vg) were injected subretinally into the left eyes of NHPs in a formal toxicology study in preparation of a clinical trial. Right eyes received sham-injection. After 3 months of in vivo, follow-up retinal sections were obtained and analyzed. The number of HRF on spectral domain-optical coherence tomography (SD-OCT) volume scans were counted from both eyes at 30 and 90 days.ResultsAnimals from the high-dose group showed more HRF than in the low (P = 0.03) and medium (P = 0.01) dose groups at 90 days. There was a significant increase in the mean number of HRF in rAAV8-treated eyes compared with sham-treated eyes at 90 days (P = 0.02). Sham-treated eyes demonstrated a nonsignificant reduction of HRF numbers over time. In contrast, a significant increase over time was observed in the rAAV8-treated eyes of the high dose group (P = 0.001). The presence of infiltrating B- and T-cells and microglia activation were detected in rAAV8-treated eyes.ConclusionsSome HRF in the retina appear to be related to the surgical trauma of subretinal injection. Although HRF in sham-treated retina tends to become less frequent over time, they accumulate in the high-dose rAAV8-treated eyes. This may suggest a sustained immunogenicity when subretinal injections of higher doses of rAAV8 vectors are applied, but it has lower impact when using more clinically relevant doses (low and medium groups).Translational RelevanceAn increase or persistence of HRFs following retinal gene therapy may indicate the need for immunomodulatory treatment.

Is Tissue Interposition Always Necessary in Transvaginal Repair of Benign, Recurrent Vesicovaginal Fistulae?

Local resection of choroidal melanomas is not widely performed so that the indications for this operation have not previously been defined statistically. Univariate and multivariate Cox regression analyses were used to identify the factors influencing visual acuity after 163 completed local resections for choroidal melanoma in patients with a preoperative visual acuity of counting fingers or better. The variables included in the analyses were patient age and sex; eye laterality and preoperative visual acuity; location of anterior and posterior tumour margins; tumour location (coronal and sagittal); tumour diameter, thickness, and cell type; ocular decompression by vitrectomy; and adequacy of surgical clearance. The surgical resections were performed using a lamellar scleral flap for eye closure, hypotensive anaesthesia for haemostasis, and, in the later years, ocular decompression by pars plana vitrectomy to improve access. The patients (94 men, 69 women) had a mean age of 50 years. The tumours had a mean diameter of 13.3 mm and a mean thickness of 7.4 mm, with 38 tumours extending to within 1 disc diameter (DD) of the optic disc, fovea or both (that is, 'posterior tumour extension'). Cox multivariate analysis showed that the most significant preoperative factors for predicting retention of good vision (6/12 or better) were nasal tumour location (p = 0.002) and distance of more than 1 DD between the tumour and the optic disc or fovea (p = 0.010). The most significant predictive risk factor for severe visual loss (hand movements or worse) was posterior tumour extension to within 1 DD of the optic disc and/or fovea (p = 0.009). One year post-operatively, all 28 patients with nasal tumours not extending to within 1 DD of the optic disc or fovea retained the eye with 57% having vision of 6/12 or better and 93% having vision of counting fingers or better. In 68 patients with temporal tumours, 90% retained the eye at 1 year with preservation of vision of counting fingers or better in 82% of 56 eyes without posterior tumours extension and in 50% of 12 eyes with posterior tumour extension. In patients with choroidal melanoma, conservation of the eye and vision can be achieved by local resection, especially if the tumour is located nasally and does not extend close to the disc or fovea.

INTRODUCTION: Numerous tissue grafts are available for posterior fossa dural augmentation after Chiari decompression surgery. The outcomes for preventing postoperative pseudomeningocele and csf leak formation vary, but no consensus exists for the graft material with lowest complication rates. Use of Alloderm has been shown to have superior outcomes with a 2.2% rate of causing pseudomeniogcele requiring reoperation. METHODS: A retrospective single institution cohort included 106 patients who underwent Chiari decompression surgery by a single surgeon from 2014 through 2021. Age, sex, BMI, tonsillar descent, syrinx formation, type of dural graft used, and follow up data were analyzed with univariate statistical tests and Chi-squared test. RESULTS: A retrospective single institution cohort included 106 patients who underwent Chiari decompression surgery by a single surgeon from 2014 through 2021. Age, sex, BMI, tonsillar descent, syrinx formation, type of dural graft used, and follow up data were analyzed with univariate statistical tests and Chi-squared test. CONCLUSION: The use of the AlloDerm dural graft with Durgen underlay for duraplasty in Chiari decompressions resulted in similar pseudomeningocele formation rate when compared with the use of Alloderm alone. However, the use of Alloderrm with Duragen underlay results in a significantly lower rate for need for reoperation. There was no association between patient age, sex, BMI, on the need for reoperation.

Research Type: Level 3 - Retrospective cohort study, Case-control study, Meta-analysis of Level 3 studies Introduction/Purpose: Transfibular total ankle arthroplasty requires a fibular osteotomy, reflection of the fibula during arthroplasty, and then fibular reduction and fixation after arthroplasty component implantation. While this approach offers advantages such as the ability to adjust fibular length and alignment in cases with coronal, sagittal and rotational deformity, some surgeons have concerns about the potential complication of fibular nonunion. The reported incidence of delayed fibular union or nonunion is highly variable, ranging from 0-18%. The purpose of this study is to examine this potential complication further by reporting our observed incidence of fibular nonunion from a single surgeon ankle arthroplasty database. Methods: We queried a total ankle replacement database from a single surgeon, examining 686 consecutive cases performed between 2012 – 2022. 406 cases had at least two year clinical follow up and had consented to study inclusion. Fibular osteotomy fixation was performed with a lateral locking plate and screw construct. Standard 3 view weightbearing ankle radiographs were analyzed at 3,6,12, and 24 months postoperatively by a fellowship trained foot and ankle orthopedic surgeon. Fibular osteotomy healing (healed vs. not completely healed) was documented at each time point based upon the appearance of mature bridging bone across the osteotomy. Rates of fibular healing at 3 and 6 months were secondarily analyzed based upon age ( &lt; 55 yo vs. &gt;=55 yo), history of diabetes, and smoking history (active or former smokers vs. nonsmokers). Secondary comparisons were made using chi-square tests (p &lt; 0.05). Results: 406 patients (208 male, 198 female) with a mean age 60 years (range 23 – 85) were included in this analysis. At 3 months, 16.3% of patients had incomplete healing at their fibular osteotomy. The rate of incomplete osteotomy healing decreased sequentially over time (5.9 % at 6 months, 1.5% at 12 months), but was stable between at 12 and 24 months (1.5%). Rates of incomplete osteotomy healing at 3 and 6 months were not statistically different based upon patient age, history of diabetes, or smoking status (p&gt;0.05). Four fibular nonunions were observed in total. Two nonunions occurred in former smokers, and one in a patient with diabetes mellitus. One nonunion was symptomatic, underwent revision fixation with bone grafting, and healed. Conclusion: In this large clinical series of consecutive transfibular total ankle arthroplasty cases, most patients had radiographic healing of the fibular osteotomy by 3 months. A small group of patients did not have complete healing for 6 to 12 months postoperatively. There was no association between osteotomy healing and patient age, smoking status, or history of diabetes at 3 and 6 months postoperatively. This secondary analysis was limited by the low overall number of fibular nonunions observed (4/406). Our results should be reassuring to surgeons with concerns about this infrequent complication (&lt; 2%) when considering lateral approach total ankle arthroplasty.

In 2012, the James Lind Alliance, together with the Craniofacial Society of Great Britain and Ireland and the Cleft Lip and Palate Association, set priorities for unanswered questions in cleft management. One of these priorities included postoperative fluid management. The authors' postoperative regimen does not include intravenous fluids unless the child fails to achieve adequate oral intake by the first evening postoperatively. This audit evaluated whether this is appropriate and safe practice. All patients undergoing cleft-related surgery by a single surgeon in a single center during August 2011 to August 2012 were included. Patient age, weight, and surgery type were recorded together with fluid requirement, length of stay, and any returns to theater or readmissions. Of the 79 patients included, none required readmission or return to theater, and the mean length of stay was 1.72 days. Nineteen patients (24%) required intravenous fluids, but these tended to be the older children in the group (P value .034). In the youngest patients undergoing primary lip repair, only 1 of 20 required intravenous fluids. This study demonstrates that, especially in the younger patients, omitting intravenous fluids as a postoperative routine is associated with a shorter length of stay without an increased complication rate. The authors advocate early postoperative feeding and the return to physiological fluid balance.

Category: Sports; Ankle; Hindfoot; Other Introduction/Purpose: Osteochondral lesions of the talus (OLT) are common injuries that are often found in patients with chronic disabling pain after ankle sprains. While OLT is becoming increasingly prevalent in the younger active population, there is disagreement and a lack of strong evidence about the impact of age on outcomes. The purpose of this study is to perform an Age- Based multivariate analysis to evaluate the clinical outcomes of Autologous Osteochondral Transplantation (AOT) for the treatment of OLT. The goals of this study are to examine trends in patient characteristics and clinical outcomes that occur with age as a statistical variable when performing AOT for the treatment of OLT. Methods: All study protocols were approved by the Institutional Review Board at the senior author's institution. A retrospective cohort study using chart review for AOT procedures on approximately 80 patients from 2006 to 2019 performed by a single surgeon. Clinical outcomes of patients were evaluated via FAOS scores for Symptoms, Pain, Activities of Daily Living, Sports and Quality of Life. A multivariable linear regression was used to assess the independent factors predictive of the first post-operative FAOS after AOT. The independent variables included in the model were pre-operative FAOS, age, defect size, whether the lesion was a shoulder lesion, cystic lesion, or a result of a traumatic injury, and whether the patient had a prior microfracture surgery. A p-value &lt;.05 was considered significant and 95% confidence limits (95% CL) for regression coefficient estimates (est.) were calculated. Results: 78 patients were included in the analysis with an average age of 35.5 +- 13.6. The average follow-up was 54.4 months +- 18.9 months, average pre-operative FAOS was 54.3 +- 19.4 and the average post-operative FAOS was 83.4 +- 13.6. The average defect size was 109.3 mm2 (std. dev. = 62.4 mm). 56 patients had a shoulder lesion, 24 had a prior microfracture surgery, 42 had a cystic lesion, and 27 had a prior traumatic injury. The multivariable linear regression showed that the pre-operative FAOS was associated with a higher post-operative FAOS (est., 95% CL: 0.16, 0.012 - 0.307; p=0.034). Defect size (est., 95% CL: -0.05, -0.097 - -0.003; p=0.0358), having a shoulder lesion (est., 95% CL: -9.068, -15.448 - -2.688; p=0.006), or having a prior microfracture surgery (est., 95% CL: -7.07, -13.118 - -1.021; p=0.0226) were associated with a lower post-operative FAOS. Conclusion: The main finding of this study is patient age was not an independent risk factor for inferior clinical outcomes after AOT for OLT. Additionally, having a cystic lesion, or having a lesion because of a traumatic injury were not significantly associated with post-operative FAOS. Having a shoulder lesion had the largest marginal effect on post-operative FAOS. These findings provide important information for providers when counseling and selecting patients for AOT procedure for treatment of OLT.

To determine overall 2- and 5-year corneal graft survival rates and to identify risk factors for corneal graft failure in our patient population. A retrospective chart review of 696 patients undergoing corneal transplantation performed by a single surgeon at The Toronto Western Hospital over a 7.5-year period. A total of 468 eyes met the inclusion criteria for this study. Overall, the 2- and 5-year graft survival rates were 78.8% and 64.5%, respectively. In a univariate analysis, patient age, gender, history of glaucoma, preoperative diagnosis, type of operative procedure, and postoperative factors all were shown to be significantly associated with graft survival. In a multivariate analysis, six independent predictors of graft failure were identified: preoperative diagnosis, neovascularization of the graft, the presence of peripheral anterior synechiae, gender, occurrence of one or more rejection episodes, and age of the recipient at the time of corneal transplantation. Risk of graft failure can vary substantially within a population of patients receiving a corneal transplant. The outcomes of this study concur with the risk factors for corneal graft failure in the literature and can be used as prognostic guidelines for both surgeons and patients.

Revascularization alone (without mitral valve repair) suffices in patients with advanced ischemic cardiomyopathy and mild-to-moderate mitral regurgitation

Reprint of: Relationship between cataract severity and socioeconomic status