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 .

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.

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.

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".

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.

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.

Decreased effect of glucantime in cutaneous leishmaniasis complicated with secondary bacterial infection

Background:

Glucantime is regarded as the first-line treatment of cutaneous leishmaniasis (CL); however, failure to treatment is a problem in many cases.

Aim:

The aim was to evaluate the therapeutic effect of glucantime in CL complicated with secondary bacterial infection compared to uncomplicated lesions.

Methods:

This experimental study was performed in Skin Diseases and Leishmaniasis Research Center, Isfahan, Iran. A total of 161 patients enrolled in the study had CL confirmed by positive smear of lesions. All the patients were treated with systemic glucantime for 3 weeks and followed for 2 months. Response to treatment was defined as loss of infiltration, reepithelization, and negative smear. Depending on the results of bacterial cultures, the lesions were divided into two groups and the efficacy of glucantime was compared.

Results:

A total of 123 patients (76.4%) were negative, and 38 patients (23.6%) were positive for secondary bacterial infection. In groups with negative bacterial culture response to treatment was 65% (80 patients) and in the other positive group, it was 31.6% (12 patients), with a difference (χ² = 13.77, P < 0.01).

Conclusion:

Therapeutic effect of glucantime showed a decrease in CL lesions with secondary bacterial infection. Therefore, in the cases of unresponsiveness to treatment, the lesions should be evaluated for bacterial infection, before repeating the treatment.

Treatment of localized psoriasis with a topical formulation of zinc pyrithione

BACKGROUND

Psoriasis is a common chronic condition of the skin that is resistant to many therapies.

AIM

To test the efficacy of a topical formulation of zinc pyrithione in an emollient base compared with an emollient alone in the treatment of psoriasis.

METHODS

This was a randomized double-blind clinical trial. Patients with localized psoriasis involving less than 10% of body skin areas were enrolled in the study. They were randomly allocated to one of two treatment groups. Group A was treated with emollient cream containing 0.25% zinc pyrithione and group B was treated with emollient cream alone twice daily for 3 months. Response to treatment was assessed using PASI scores.

RESULTS

Of 60 participants, 30 patients in group A and 30 patients in group B completed the study. The mean PASI scores before and after treatment were 3.4±1.8 and 0.9±1.3 in group A (p<0.01), and 4.3±2 and 3.9±1.3 in group B (p>0.05), and there was a significant difference between the two groups' mean PASI scores at the end of the study (p<0.01). The differences in the mean PASI scores before and after treatment were 2.4±2 and 0.4±0.1 in groups A and B, respectively (p<0.01).

CONCLUSION

A topical formulation of zinc pyrithione can be used to treat localized psoriasis.

Seroprevalence of Toxoplasma gondii in cattle, sheep and goats slaughtered for food in Mazandaran province, Iran, during 2005

Serum samples from 290 cattle, 400 goats and 588 sheep slaughtered for food in various areas of the Mazandaran province, Iran were tested for antibodies to Toxoplasma gondii by the indirect immunofluorescence antibody test (IFAT), from December 2004 to April 2005. Antibodies to T. gondii were found in 30% (120/400) goats and 35% (206/588) sheep and 0% (0/290) cattle, at a dilution of 1:16 or more for goats and sheep and 1:128 or more for cattle. The highest titres observed in cattle, goats and sheep were 1:64 (0.7%), 1:128 (1%), 1:64 (2%), respectively. These results indicate that T. gondii antibodies are widespread in the animal populations and suggest that toxoplasmosis is a widely spread zoonotic infection in northern Iran.

Seroepidemiological study of toxoplasmosis in intellectual disability children in rehabilitation centers of northern Iran

Serological studies revealed that toxoplasmosis has world wide distribution. Although the infection by Toxoplasma gondii is widely prevalent in humans and animals, the disease is uncommon and most of the acquired infections are asymptomatic. The important aspect of this parasitic infection is the probable danger of congenital transmission and its severe effects on the fetus. There have been many reports about the prevalence of anti-T. gondii antibody among different groups of people in Iran; however the epidemiological data in intellectual disability (ID) persons are rare. This study was performed to evaluate the seroprevalence of toxoplasmosis among the inhabitants of rehabilitation centers of northern Iran. A total of 336 serum samples (161 males, 175 females) were examined for the IgG antibodies by indirect immunofluorescense technique. First of all, 1:50 titer dilution was tested, in the cases of positive result, further dilutions (1:100, 1:200, 1:400, 1:800, 1:1600, and 1:3200) were prepared and the last dilution was recorded. Among 336 sera, 77.4% showed seropositivity by IFAT. The positive rates of males and females were 77.6% (125/161) and 80% (140/175), respectively. However, there were no significant differences between sexes. Comparing the age groups, the highest seropositive rate showed in 19 or higher, and their rates had a tendency to increase with age. Prevalence of the infection in 10 rehabilitation centers was not significant either. Nevertheless, our data (77.4%) in rehabilitation centers in northern Iran suggest that infection is the same as in many other reports in normal population in this area, therefore toxoplasmosis is not a major problem in rehabilitation centers of this geographical area.

Toxocara catiinfections in stray cats in northern Iran

A cross-sectional survey was undertaken to study the prevalence and intensity of infection withToxocara catiin 100 stray cats, from April to October 2004 in urban areas of Sari, northern Iran. A total of 44 cats (44%) were found to be infected withT. cati. There was a significant difference in the prevalence of infection relative to host age and weight (P = 0.000). There was also a significant difference in the intensity of infection relative to body weight and urban sites (P < 0.05). No significant difference was found between the prevalence of infection relative to host gender, urban sites and season (P>0.05), nor in the intensity of infection between host gender, age and season (P>0.05). The intensity of infection ranged from 1 to 32 worms per cat, with a mean of 7.30 ± 6.82.

The prevalence, intensity and viability of hydatid cysts in slaughtered animals in the Ardabil province of Northwest Iran

In a cross-sectional study, a total of 5381 slaughtered animals, namely 928 cattle, 243 buffaloes, 3765 sheep and 445 goats were inspected macroscopically for hydatid cysts in northwest Iran, with prevalence values of 38.3%, 11.9%, 74.4% and 20%, respectively, being recorded. Prevalences were higher in females compared with males, but a significant difference (P < 0.001) was only found in sheep and cattle. Most cases which were condemned were seen in the lungs of sheep (13.4%) indicating that sheep are the most important intermediate hosts for Echinococcus granulosus in this area.