THE LONG-TERM RECOVERY OF VISION IN PSEUDOPHAKIC MACULA-OFF RHEGMATOGENOUS RETINAL DETACHMENTS.

PURPOSE: To assess the long-term visual recovery in uncomplicated macula-off pseudophakic rhegmatogenous retinal detachment treated with pars plana vitrectomy and gas tamponade in the absence of other visual comorbidities. METHODS: Single-center retrospective longitudinal study on eyes with macula-off pseudophakic rhegmatogenous retinal detachment successfully treated with pars plana vitrectomy between 2011 and 2020 and with at least 2 follow-ups (FU), first gas-free FU (first-FU) and a final-FU, were included. Patients with subsequent ocular surgery or comorbidities affecting best-corrected visual acuity were excluded. The duration between operation date and final-FU was calculated (total days FU) and split into total days quintiles-1: ≤57, 2: >57 and ≤77, 3: >77 and ≤152, 4: >152 and ≤508, and 5: >508 days. Multivariable regression was performed with logMAR gain between the first and the final-FU as the dependent variable. RESULTS: In 209 eyes, the authors report association with increase of logMAR gain between the first and the final-FU, with reducing clock hours of pseudophakic rhegmatogenous retinal detachment ( P = 0.041) and relative to the total days Quintile 1. Mean (SD) logMAR gain between the first and the final-FU was 0.02 (0.07) in the first quintile, increasing to 0.14 (0.13) ( P < 0.001) by the fifth quintile on multivariable regression. For patients not achieving 0.30 logMAR at the first-FU, this was attained at the final-FU with a sensitivity of 51.9% and specificity of 95.5% at a cut off ≤0.58 logMAR at the first-FU (area under the curve 0.756 [95% confidence interval 0.664-0.848], P < 0.001). CONCLUSION: The authors report a significant time-dependent visual improvement after uncomplicated pars plana vitrectomy with gas tamponade for macula-off pseudophakic rhegmatogenous retinal detachment without visual confounders and provide important quantitative data for counselling patients with macula-off repair.

SF 6 COMPARED WITH C 2 F 6 FOR INFERIOR RHEGMATOGENOUS RETINAL REPAIR : The Manchester Pseudophakic Retinal Detachment Study.

PURPOSE: To compare SF 6 relative with C 2 F 6 in the anatomical and functional outcomes following pars plana vitrectomy for uncomplicated primary pseudophakic rhegmatogenous retinal detachment with inferior causative breaks. METHODS: This is a retrospective, comparative study on eyes with pseudophakic rhegmatogenous retinal detachment with inferior causative breaks that had small-gauge pars plana vitrectomy repair using SF 6 and C 2 F 6 tamponade between 2011 and 2020 at a tertiary centre in the United Kingdom. Primary outcome was single surgery anatomical success, and the secondary outcome was best-corrected visual acuity. Propensity score matching, using preoperative findings as covariates to account for relevant confounders, was performed. RESULTS: From 162 pseudophakic rhegmatogenous retinal detachment eyes with inferior causative breaks, the median (interquartile range) follow-up was 82 (52-182) days. The single surgery anatomical success was 156 (96.3%) overall: 47 of 47 (100.0%) and 109 of 115 (94.8%) in the SF 6 and C 2 F 6 groups, respectively ( P = 0.182). Relative to the SF 6 group, the C 2 F 6 group had a higher mean number of tears (SF 6 : 3.1[2.0], C 2 F 6 : 4.5[2.7], P = 0.002) and greater retinal detachment extent (SF 6 : 5.3[2.9], C 2 F 6 : 6.2[2.6] clock hours, P = 0.025). Following propensity score matching analysis, 80 eyes were matched with 40 in each group to homogenize preoperative factors. No significant difference was found in single surgery anatomical success and best-corrected visual acuity between the groups following propensity score matching. CONCLUSION: Primary pars plana vitrectomy with gas tamponade leads to a high single surgery anatomical success rate in uncomplicated pseudophakic rhegmatogenous retinal detachment with inferior causative breaks with no additional benefit associated with long-acting tamponade when comparing C 2 F 6 with SF 6 .

Expansile gas concentration in primary pseudophakic retinal detachment repair, effect on intraocular pressure and outcomes; the Manchester Pseudophakic Retinal Detachment Study.

PURPOSE: To investigate the effect of isovolumetric and expansile gas tamponade concentrations on single surgery anatomical success (SSAS) and day 1 intraocular pressure (IOPD1) following pars plana vitrectomy (PPV) for mild-moderate complexity primary pseudophakic rhegmatogenous retinal detachment (PRD). METHODS: We conducted a single-centre retrospective continuous and comparative study on eyes that had undergone small-gauge PPV using isovolumetric versus expansile gas for PRD repair between 2011 and 2020 at a single tertiary vitreoretinal centre in UK. We performed propensity score matching (PSM) using preoperative findings as covariates to account for relevant confounders. Significant risk factors such as proliferative vitreoretinopathy C or giant retinal tears were excluded. RESULTS: From 456 eyes, PSM analysis matched 240 eyes with 120 in each group. The median (interquartile range) follow-up was 96 (59 to 218) days. The SSAS was 229/240 (95.8%) overall; 115/120 (95.8%) and 114/120 (95.0%) in isovolumetric and expansile groups, respectively (p = 1.000). Relative to the isovolumetric group, the expansile group had lower proportion of eyes with IOP ≤ 21 mmHg (odds ratio, 95% confidence interval, 0.40 [0.23-0.68], p < 0.001); but significantly higher number of eyes with IOP ≥ 22 mmHg (2.53 [1.48-4.34], p < 0.001), ≥ 25 mmHg (2.77 [1.43-5.33], p < 0.001), ≥ 30 mmHg (2.90 [1.28-6.58], p = 0.006) and ≥ 40 mmHg (p = 0.029, isovolumetric: 0 [0%] vs expansile group: 6 [5%]). There was only one case of hypotony (≤ 5 mmHg) 1/240 (0.4%) which occurred in the expansile group. CONCLUSIONS: Expansile gas concentration does not impact SSAS but is associated with significantly raised IOPD1 with no reduction in hypotony rates following PPV for primary PRD.

LASER PROPHYLAXIS IN STICKLER SYNDROME: The Manchester Protocol.

PURPOSE: Patients with Stickler syndrome are at high risk of giant retinal tears (GRTs) and detachments. Vitreoretinal interventions can reduce this risk, but there is presently no consensus about the optimal prophylactic approach. The aim of our study was to determine whether 360° laser prophylaxis is a safe and effective procedure to prevent GRT detachments in patients with Stickler syndrome. METHODS: Study subjects were recruited retrospectively through the databases of the vitreoretinal and ophthalmic genetic tertiary services in Manchester, United Kingdom. Clinical data were collected including on prophylactic intervention, the occurrence of retinal detachment, and the presence/type of retinal breaks. RESULTS: One hundred thirteen eyes from 63 patients with Stickler syndrome were studied; 72.6% (82/113) of these eyes received 360° laser prophylaxis. Of these, 9% had a retinal detachment, but no GRTs occurred. Among the 27.4% (31/113) of eyes that had no prophylactic treatment, 23% suffered a retinal detachment and 42.9% of these were associated with a GRT. CONCLUSION: Patients who underwent laser prophylaxis had fewer retinal detachments and no GRTs during an average of 6.1 years of follow-up (median 5 years), suggesting that this is a safe and effective approach for individuals with Stickler syndrome.

PREDICTION OF MACULAR HOLE SIZE PROGRESSION BASED ON BASELINE OPTICAL COHERENCE TOMOGRAPHY FINDINGS.

PURPOSE: To quantify the rate of idiopathic macular hole progression from presentation and identify factors that may influence stratification and urgency for surgical listing based on the initial optical coherence tomography scans. METHODS: The minimal linear diameter (MLD), base diameter (BD), and hole height on nasal and temporal sides of idiopathic macular hole were measured on spectral domain optical coherence tomographies, on initial presentation and just before surgery. Mean hole height, hole height asymmetry (absolute difference between nasal and temporal height), MLD/BD, and MLD change per day (MLD/day) were calculated for each patient. Multivariable linear regression analysis with MLD/day as the dependent variable was performed to identify significant risk factors for MLD progression. Minimal linear diameter was grouped to quintiles: 1: ≤290 µ m, 2: >290 µ m and ≤385 µ m, 3: >385 µ m and ≤490 µ m, 4: >490 µ m and ≤623 µ m, and 5: >623 µ m. RESULTS: In 161 eyes (157 patients), we report significant associations with MLD/day: 1) MLD/BD ( P = 0.039) (i.e., wide BD relative to MLD lead to faster progression of MLD), 2) hole height asymmetry ( P = 0.006) (larger absolute difference between nasal and temporal hole height lead to faster progression), and 3) days between scans ( P < 0.001) (longer duration between scans had reduced MLD/day, indicating more rapid increase initially then plateaux), and relative to MLD Quintile 1, MLD Quintile 3 ( P = 0.002) and MLD Quintile 4 ( P = 0,008), and MLD Quintile 5 ( P < 0.001) all lead to a reduced MLD/day rate on multivariable regression. CONCLUSION: In addition to finding that the previously reported initial smaller MLD is a risk factor for rapid MLD progression, we report two novel findings, large hole height asymmetry and a low MLD/BD (wide base relative to MLD), that represent significant risk factors. These factors should be taken into consideration on presentation to stratify timing of surgery.

STEP-WISE APPROACH TO THE MANAGEMENT OF SUBMACULAR HEMORRHAGE USING PNEUMATIC DISPLACEMENT AND VITRECTOMY: The Manchester Protocol.

PURPOSE: To evaluate a sequential approach of pneumatic displacement followed by vitrectomy (pars plana vitrectomy) in failed cases to deal with submacular hemorrhage (SMH) of various etiologies. METHODS: Retrospective, nonrandomized interventional case series of consecutive patients with SMH of up to 2 weeks' duration, who were treated with a stepwise approach. Step 1 involved intravitreal injection of 0.3 mL 100% C3F8 and recombinant tissue plasminogen activator 50 µg/0.1 mL. If unsuccessful, a prompt pars plana vitrectomy with subretinal recombinant tissue plasminogen activator 50 µg/0.1 mL and 20% SF6 gas tamponade was performed as a second attempt to displace the SMH. RESULTS: Thirty-one patients with SMH underwent pneumatic displacement; 24 (77.4%) had a successful outcome without further intervention. The mean presenting visual acuity of the "successful cohort" was 1.34 logMAR (20/440 Snellen), improving to 0.83 logMAR (20/135 Snellen) 1 month after treatment. Five of the seven patients with failed pneumatic displacement underwent pars plana vitrectomy with subretinal recombinant tissue plasminogen activator at an average of 5 days poststep 1, with successful SMH displacement in 3 patients, giving an overall success of 87.1% for this treatment protocol. CONCLUSION: A sequential approach of expansile gas injection followed by prompt pars plana vitrectomy, aided by recombinant tissue plasminogen activator at both steps, is a coherent, logical pathway to treat SMH with high anatomical and functional success.

MANCHESTER REVISIONAL MACULAR HOLE STUDY: Predictive Value of Optical Coherence Tomography Parameters on Outcomes of Repeat Vitrectomy, Extension of Internal Limiting Membrane Peel, and Gas Tamponade for Persistent Macular Holes.

PURPOSE: To evaluate the efficacy of repeat pars plana vitrectomy and gas tamponade for persistent macular holes (MHs), especially looking at a predictive value of optical coherence tomography parameters in revisional surgery. METHODS: Retrospective, nonrandomized interventional case series of consecutive patients with a persistent MH that underwent revisional pars plana vitrectomy and gas tamponade. The primary outcome measure was anatomical closure of the MH after revisional surgery. The secondary outcome measure was a functional outcome of the MH closure based on the best-corrected visual acuity. The changes of minimum linear diameter and MH index after the primary surgery were evaluated to see if they were prognostic markers of success for the revisional surgery. RESULTS: A total of 27 patients with a persistent MH after primary MH surgery were identified, all of whom underwent a second operation with pars plana vitrectomy and gas tamponade with an internal limiting membrane peel extension in 20 cases. The MH closure rate after revisional surgery was 89% (24/27). Twenty-two cases were included in the optical coherence tomography analysis, of which 14 MHs that showed both a reduction of the minimum linear diameter and an increase in the MH index after the primary repair closed after revisional surgery. The mean best-corrected visual acuity before revisional surgery was 0.86 logMAR (20/145 Snellen) but increased significantly postoperatively to 0.69 (±0.15) logMAR (20/98 Snellen) at 3 months and to 0.49 logMAR (20/62 Snellen) at 12 months. CONCLUSION: For a persistent idiopathic MH, simple repeat pars plana vitrectomy with gas tamponade has a good anatomical and functional success rate in selected cases. The minimum linear diameter and MH index can be useful optical coherence tomography markers for prognostic guidance.

Volumetric Biomarkers of Visual Outcome after Surgical Repair in Lamellar Macular Holes.

BACKGROUND: We investigate novel OCT parameters, based on the volumetric analysis of lamellar macular holes (LMHs), as prognostic indicators for visual outcomes after surgery. METHODS: LMHs were divided into degenerative LMHs (D-LMHs) and ERM-foveoschisis (ERM-FS). Pre-operative clinical, OCT linear and volumetric parameters were collected. Volumes were obtained using the OCT automatic segmentation, such as central retinal volume (CRV) and outer nuclear layer (ONL) volume, or using a novel method to calculate volumes of specific LMH entities like epiretinal proliferation (ERP), foveal cavity (FC) in D-LMH and schitic volume (SV) in ERM-FS. Univariate and multivariate linear regression analysis evaluated the factors predictive for post-operative best-corrected visual acuity (BCVA). RESULTS: We included 31 eyes of 31 patients (14 D-LMH,17 ERM-FS). A pre-operative BCVA ≤ 0.48 logMAR was a predictor for achieving ≤0.30 logMAR at final follow-up. A lower pre-operative BCVA (p = 0.008) and the presence of ERP (p = 0.002) were associated with worse visual outcomes post-surgery. Moreover, novel pre-operative OCT parameters significantly associated with worse post-operative BCVA, such as increased FC volume (p = 0.032) and lower CRV (p = 0.034) in the D-LMH subtype and lower CRV (p < 0.001) and ERP volume (p < 0.001), higher SV (p < 0.001) and foveal ONL volume (p < 0.001) in the ERM-FS subtype. CONCLUSIONS: Novel volumetric OCT parameters can be prognostic indicators of visual outcome following surgery in LMHs.

AUTOLOGOUS RETINAL TRANSPLANT FOR REFRACTORY SEROUS RETINAL DETACHMENT SECONDARY TO OPTIC DISK PIT: A NOVEL SURGICAL APPROACH.

PURPOSE: To present a new technique to treat refractory retinal detachment secondary to optic disk pit. METHODS: An interventional case report. RESULTS: A 25-year-old man with congenital optic disk pit had two failed vitrectomies involving laser around the optic disk, internal limiting membrane peel and flap to plug the disk pit, and gas tamponade to reattach the retina. With all options running out, a further vitrectomy with autologous retinal transplant and silicone oil tamponade was performed to treat the refractory serous retinal detachment; the silicone oil was removed at 6 weeks after the last procedure. The retina remained successfully attached at 6 months postsurgery with the patient maintaining his baseline visual acuity. CONCLUSION: The use of autologous retinal transplant is a new approach to treat refractory retinal detachment secondary to congenital optic disk anomalies, and adds to our options of dealing with this complex condition when first-line approaches have failed.

Unilateral retinal neovascularization associated with recurrent vitreous hemorrhage in a patient with gyrate atrophy.

BACKGROUND/PURPOSE: To describe the first case of unilateral peripheral retinal neovasularization associated with recurrent vitreous hemorrhage and localised tractional retinal detachment in a patient with gyrate atrophy (GA). METHODS: Interventional case report. RESULTS: A 23-year-old man with confirmed diagnosis of gyrate atrophy presented with vitreous hemorrhage and history of stable peripheral inferior tractional retinal detachment in the left eye. After three months, the vitreous hemorrhage partially reabsorbed and peripheral retinal vascular abnormalities with focal neovascularization were detected with associated tractional retinal detachment and confirmed on fluorescein angiography. Cryotherapy was performed to prevent any further bleeding. Twelve months later, the left eye remained stable and no further vitreous bleeding occurred. CONCLUSIONS: The combination of peripheral retinal neovascularization, localised tractional retinal detachment and recurrent vitreous hemorrhage can be a unilateral complication of gyrate atrophy. In similar cases, cryotherapy may represent a valuable therapeutic option to prevent recurrent bleeding.

Retinal gene therapy in RPE-65 gene mediated inherited retinal dystrophy.

BACKGROUND: Voretigene neparvovec (VN) is a gene therapeutic agent for treatment of retinal dystrophies caused by bi-allelic RPE65 mutations. We illustrate, both the benefits and pitfalls associated with ocular gene therapy in the same patient. METHODS: Two eyes of one patient with bi-allelic RPE65 mutations have been treated with VN. The clinical examinations included visual acuity (VA, in normal and low luminance), colour vision, contrast sensitivity, International Society for Clinical Electrophysiology of Vision (ISCEV) standard retinal electrophysiology and dark-adapted full-field stimulus threshold (FST), Goldmann VF analysis and imaging studies, including optical coherence tomography (OCT) and autofluorescence. These were performed at baseline, 2-weeks, 3 and 6-months, 1 and 2-years follow-up. RESULTS: The first eye showed improvement in rod photoreceptor function with increased peripheral and low luminance vision (baseline VA: 0.9 logMAR and 2-years post-operative VA: 0.7 logMAR). The second eye, whilst showing increased light sensitivity, suffered a drop in central vision (at 2-weeks) with loss of foveal photoreceptors as shown by the loss of ellipsoid zone on OCT scan (baseline VA: 0.6, 2-year post-operative VA: 1.2). FST improvements were maintained in both eyes indicating a sustained efficacy of VN with little waning of its effect. CONCLUSIONS: We present a previously unreported adverse complication of subretinal VN therapy in bi-allelic RPE65, indicating a probable immune response in treatment of the second eye, resulting in loss of foveal photoreceptors. This case-series highlights the potential and pitfalls of retinal gene therapy in the same patient. The immune responses of the body to a 'foreign vector', remains a challenge.

The use of fluorinated gases and quantification of carbon emission for common vitreoretinal procedures.

PURPOSE: To report the contribution to carbon dioxide equivalent mass [CO2EM] of various types of VR surgery performed across three tertiary referral centres, according to their indication and fluorinated gas used. We secondarily reported on the difference in tamponade choice, and CO2EM between the different centres. MATERIALS: Retrospective, continuous, comparative multicentre study of all procedures using fluorinated gases between 01/01/17-31/12/20 at the Manchester Royal Eye Hospital and Birmingham and Midland Eye Centre, and between 01/01/19-31/12/2020 at the University Hospitals Coventry and Warwickshire. RESULTS: Across 4877 procedures, the use of fluorinated gases produced 284.2 tonnes (71.2 tonnes annually) CO2EM; an annual consumption of 30,330 l of gasoline. Rhegmatogenous-retinal-detachment (RRD) and macular hole repair had the highest CO2EM by indication, accounting for 191.4 tonnes CO2EM (67.3%) and 28.6 tonnes CO2EM (10.1%); a mean 60.0 kg and 32.0 kg of CO2EM produced per surgery respectively. The use of fluorinated gases and their respective CO2EM contributions were significantly different across all three centres (p < 0.001) for all indications. SF6, despite being used in 1883 procedures (38.6%), contributed to 195.5 tonnes CO2EM (68.8%). Relative to C2F6, procedures using C3F8 and SF6 produced 1.9 and 4.4 times more CO2EM. CONCLUSION: We demonstrated that SF6 causes significantly higher carbon emissions relative to C2F6 and C3F8 with RRD and macular hole repair having the greatest environmental impact. We also reported large variations between different large VR centres in fluorinated gas use, and therefore in carbon emission contributions depending on indications for surgery. Evidence-based protocols might help in making VR surgery "greener".

The impact of 360-laser barricade on outcomes of vitrectomy for pseudophakic retinal detachment; The Manchester Pseudophakic Retinal Detachment Study.

PURPOSE: To investigate the anatomical and functional outcomes and specifically, the effect of 360-degree barrier-laser, in pars plana vitrectomy (PPV) for primary pseudophakic rhegmatogenous retinal detachment (PRD). METHODS: We conducted a single-centre retrospective, continuous and comparative study on eyes that had undergone PPV with focal-retinopexy (laser or cryotherapy) versus 360-laser for PRD repair between 2011-2020 at a single tertiary vitreoretinal centre in the UK. Primary outcomes were single surgery anatomical success (SSAS) rate and final postoperative visual acuity (VA). Multivariable regression covariates for primary re-detachment included age, gender, onset-of-detachment, pre-operative VA, ocular co-morbidities, macula-status, majority inferior (vs superior) PRD, number-of-tears and PRD extent (in clock-hours), 360-laser barricade, and perfluorocarbon liquid (PFCL) use. For VA gain, primary re-detachment was added as a covariate. RESULTS: We included 467 eyes with a mean follow-up of 388 (161) days. The SSAS was 444/467 (95.1%) overall, and 351/370 (94.9%) and 93/97 (95.9%) in focal-retinopexy and 360-laser groups, respectively (p = 0.798). Compared to the focal-retinopexy group, the 360-laser group had significantly worse post-operative VA but similar logMAR gain (p = 0.812). A multivariable binary logistic regression found that only PFCL use was linked with increased primary re-detachment (OR:5.32 [p = 0.048]) and 360-laser did not contribute to increased SSAS. A multivariable linear regression analysis showed that poor logMAR gain was significantly associated with better pre-operative logMAR, ocular co-morbidities, greater PRD extent, use of 360-laser and primary re-detachment. However, when excluding macula-off RD (n = 211), 360-laser was no longer significant (p = 0.088). CONCLUSIONS: Prophylactic 360-laser does not seem to impact on SSAS and functional outcomes following PPV for primary PRD.

Long-Term Safety and Efficacy of Pars Plana Vitrectomy for Uveitis: Experience of a Tertiary Referral Centre in the United Kingdom.

AIM: To evaluate the effectiveness of pars plana vitrectomy (PPV) without macular intervention on uveitis eyes with persistent vitreous inflammation/opacities in terms of visual acuity (VA), intraocular inflammation and macular profile. METHODS: We carried out a single-center retrospective study of patients with uveitic eyes that underwent PPV without intervention on the macula due to persistent vitreous inflammation/opacities. The primary outcome measures were best-corrected visual acuity (BCVA), intraocular inflammation and macular profile at 3, 12 and 24 months after surgery. RESULTS: Twenty-seven eyes of twenty-six patients were analyzed. Overall, 77.8% had an improvement of VA (55% by 0.3 LogMAR or more); 62.5% of patients had no intraocular inflammation, and the number of patients on systemic steroids and second-line immunosuppressives was reduced by 26% at 12 months; 87.5% of patients had resolution of macular oedema at 12 months. CONCLUSION: PPV for persistent vitreous inflammation/opacities is safe and effective, showing beneficial outcomes in terms of improvement of BCVA and the reduction in inflammation.

Early Pars Plana Vitrectomy in Acute Endophthalmitis: The Manchester Series.

BACKGROUND AND OBJECTIVE: Current literature lacks good-quality evidence regarding the outcomes of early pars plana vitrectomy (PPV) for acute exogenous endophthalmitis. The aim for this study was to analyze and discuss the outcomes of PPV for endophthalmitis in a UK tertiary hospital. PATIENTS AND METHODS: This study was a retrospective case series. The clinical records of consecutive patients who had PPV for acute exogenous endophthalmitis were reviewed. Demographic data, etiology, timing of onset, timing of PPV, intraand postoperative complications, baseline and final best-corrected visual acuity (BCVA), therapeutic regimens, and microbiology details were collected. Primary efficacy and safety outcome measures were BCVA improvement of two or more logMAR lines and intra- or postoperative complications, respectively. RESULTS: Forty-one patients with a median age of 76 (interquartile range, 64 to 82) years were studied. The most common etiology was intravitreal injection (41%), followed by phacoemulsification (34%). Median interval to PPV was 1.0 (interquartile range, 1.0 to 3.0) days. In a multivariate model controlling for age, baseline BCVA, microbiology positivity, and etiology (post-intravitreal injection), PPV after 24 hours was seven times more likely to achieve significant BCVA improvement (odds ratio, 7.47; 95% confidence interval, 1.12 to 49.66; P = .038). PPV within 24 hours of presentation was associated with more intraoperative complications. CONCLUSIONS: Favorable outcomes may be achieved with current antibiotic regimens and PPV for endophthalmitis. The series suggests that an early surgical intervention may be associated with poorer functional outcomes. Tap and inject at presentation, followed by a semi-urgent PPV as required, seems to be a sensible approach. [Ophthalmic Surg Lasers Imaging Retina. 2022;53:96-102.].

Environmental effect of air versus gas tamponade in the management of rhegmatogenous retinal detachment VR surgery: A multicentre study of 3,239 patients.

PURPOSE: To report the potential reduction of carbon emissions by utilising air-tamponade (AT), where possible, instead of fluorinated gases in the management of rhegmatogenous retinal detachment (RRD). We compared the carbon CO2 emissions produced at two large tertiary referral vitreoretinal (VR) centres where RRD are exclusively repaired using fluorinated gases to a tertiary VR mass of each gas used according to the Intergovernmental Panel on Climate Change. MATERIALS AND METHODS: Retrospective, continuous, comparative multicentre study of all procedures using fluorinated gases between 01/01/17-31/12/20 at the Manchester Royal Eye Hospital (MREH) and Birmingham and Midland Eye Centre (BMEC), and between 01/01/19-31/12/2020 at the University Hospitals Coventry and Warwickshire (UHCW). RESULTS: We report on 3,239 (SF6:1,415 [43.7%], C2F6:1,235 [38.1%], C3F8:541 [16.7%], Air:48 [1.5%]) procedures. UHCW and BMEC utilise single use 30ml and 75ml cannisters, respectively and MREH use multi-use gas cylinders. UHCW used AT in 48 (70%) of RRD repairs. Mean equivalent mass CO2/patient was MREH:115.9kg, BMEC:7.9kg and UHCW:1.9kg. If assuming all centres used 30ml cannisters, the mean equivalent mass CO2/patient was MREH:3.5 kg, BMEC:3.1kg and UHCW:1.9kg. AT enabled UHCW to greatly reduce the need for the most environmentally damaging SF6 gas, leading to lower CO2 emissions by 47.0% and 41.1% compared to MREH and BMEC, respectively. CONCLUSION: We demonstrate how AT vs. the fluorinated gases can reduce in carbon footprint in the management of RRD. Further studies are required to determine the most 'environment-friendly' intraocular tamponade without compromising patient outcomes centre that also routinely employs AT in selected RRD cases.

Environmental Effect of Fluorinated Gases in Vitreoretinal Surgery: A Multicenter Study of 4,877 Patients.

PURPOSE: To investigate the direct contribution to carbon emissions of fluorinated gases used in all vitreoretinal (VR) procedures utilizing gas tamponade and assess the respective carbon footprint of the three different gas delivery systems. DESIGN: A multicenter, retrospective, environmental impact study. METHODS: All VR procedures using fluorinated gases between 2017 to 2020 at the Manchester Royal Eye Hospital (MREH) and Birmingham and Midland Eye Centre (BMEC) (the second and third largest VR centers in the UK), and between 2019 to 2020 at the University Hospitals Coventry and Warwickshire (UHCW) were included. CO2 equivalent mass (CO2EM) was calculated from the mass of each gas used, according to the Intergovernmental Panel on Climate Change. RESULTS: A total of 4877 (1883 SF6 [38.6%], 2096 C2F6 [43.0%], and 897 C3F8 [18.4%]) procedures were analyzed. UHCW and BMEC utilized single-use 30 mL and 75 mL cannisters, respectively. MREH used four cylinders of each gas over 4 years (2 kg SF6, 1 kg C2F6, 1 kg C3F8). Mean CO2EM per patient was: MREH 111.8 kg, BMEC 7.5 kg, and UHCW 2.7 kg. For MREH and BMEC, the CO2EM was 73.4 metric tons annually (if all cases were performed with i) 30 mL: 3.7 tons and ii) cylinders: 148.0 tons, x 40-fold difference), equating to 599,400 (30,500-1.2 million) km travelled by a passenger car. The current use of SF6 in VR surgery accounts for 0.11% of total SF6 use; if 30 mL cylinders were exclusively used in the UK, this could be lowered to 0.01%. CONCLUSIONS: This study highlights the significant waste associated with large gas cylinders and demonstrated that 30 mL cannisters can lead to a marked reduction in carbon emissions, even after accounting for the increased carbon footprint involved in their manufacture and disposal.

Functional and Anatomical Outcomes of Pars Plana Vitrectomy for Epiretinal Membrane in Patients with Uveitis.

Purpose-To evaluate the anatomical and functional outcomes of vitrectomy and epiretinal membrane (ERM) peeling in patients with uveitis. Secondarily, we evaluated the effect of internal limiting membrane (ILM) peeling on surgical outcomes, and of surgery on uveitis activity and, thus, therapeutic regime. Methods-Bicentre, retrospective, interventional case series of 29 eyes of 29 consecutive patients affected by uveitis and ERM, that had undergone pars plana vitrectomy with ERM peel between 2012 and 2020, with a minimum postoperative follow-up (FU) of six-months. Demographic data, best-corrected visual-acuity (BCVA), clinical findings, intraoperative and postoperative complications, and macular optical-coherence-tomography scans were reviewed. Results-The mean (standard deviation) duration of follow-up was 32 (22) months. At six-month FU, mean central-retinal-thickness (CRT) significantly improved (from 456 (99) to 353 (86) microns; p < 0.001), and mean BCVA improved from 0.73 (0.3) to 0.49 (0.36) logMAR (p < 0.001), with only one (3%) patient experiencing worsening of vision. The rate of concomitant cystoid macular edema decreased from 19 (66%) eyes at presentation to eight (28%) eyes at final-FU (p = 0.003). Comparing eyes in which ILM peeling was performed in addition to ERM peeling only, BCVA or CRT reduction were comparable. Only a minority of six (21%) eyes had a worsening in uveitis activity requiring additional medications, whereas most patients resumed the same treatment (52%) or received less treatment (28%) (p = 0.673). Conclusions-Vitrectomy with ERM peeling led to favourable anatomical and functional outcomes in patients with uveitis regardless of whether the ILM is peeled or not. As in most patients, no activation of the uveitis requiring additional medications was noted, we do not recommend changes in anti-inflammatory/immunosuppressive therapy postoperatively.