Central serous chorioretinopathy: A review.

Central serous chorioretinopathy (CSC) is the fourth most common non-surgical retinopathy associated with fluid leakage. The pathogenesis is not yet completely understood, but changes in the choroid, sclera and RPE have been described associated with venous congestion of choroidal outflow. CSC can be categorised into acute, chronic, and recurrent subtypes with recent classifications of simple and complex based on the area of RPE change seen on fundus autofluorescence. A multimodal imaging approach is helpful in the diagnosis and management of CSC and secondary complications such as type 1 neovascularisation. Although spontaneous resolution with relatively good visual outcomes is common, treatment should be considered in patients with persistent or recurrent SRF. Treatment options include laser, systemic medications, intravitreal therapy, and surgery. Of these, argon laser for focal extramacular fluid leaks and photodynamic therapy of leakage identified by indocyanine-green angiography currently have the greatest supportive evidence.

Nasal turbinate mucosal graft for management of contracted anophthalmic socket.

A 67-year-old Caucasian male presented with severe contraction of socket lining 8 years after enucleation, dermis fat graft and successful ocular prosthesis fitting. Following two failed attempts at using amniotic membrane grafts to reform the socket lining, a total socket reconstruction was attempted using a novel nasal turbinate mucosal graft technique. This was performed in a staged fashion with lower fornix reconstruction followed by upper fornix reconstruction 3 months later. The patient was stable at 12 months review, with a satisfactory cosmetic outcome. Nasal turbinate mucosa was used as it was surgically accessible, provided natural socket lubrication due to its mucosal surface, and avoided oral mucosa and its associated morbidity. This case report suggests that nasal turbinate mucosa is a suitable autologous grafting material for total socket reconstruction in contracted anophthalmic sockets.

Glomerella cingulata endophthalmitis.

Purpose: To report a case of an exogenous endophthalmitis caused by the fungal species Glomerella cingulata. Observations: A 71-year-old male presented with an infectious keratitis that evolved into endophthalmitis. Combined cataract extraction and pars plana vitrectomy was performed and the vitreous specimen cultured Glomerella cingulata, a variant of the Colletotrichum gloeosporioides fungal species. Despite early treatment with topical, systemic and intravitreal doses of both voriconazole and amphotericin B, the patient had a poor visual and anatomical outcome. Conclusions and Importance: Glomerella cingulata may rarely cause endophthalmitis with devastating visual outcomes.

Mechanical and Geometric Analysis of Fenestration Design for Polymethylmethacrylate-Augmented Pedicle Screw Fixation.

BACKGROUND: The practice of cement augmentation in pedicle screw fixation is well established. However, there is a lack of consensus regarding the optimal screw design or cement type. This remains a clinically important question given the incidence of cement augmentation-associated complications. While fenestrated screws have become widely used in clinical practice, the relationship between fenestration placement along the screw axis and cement plume geometry and pullout strength have yet to be clarified. This study was designed to evaluate the mechanical and geometric properties of different fenestrated screw designs and cement viscosities in pedicle screw fixation. METHODS: Three different screw fenestration configurations and 2 different cement viscosities were examined in this study. Axial pullout tests were conducted in both foam blocks and cadaveric vertebrae. All vertebral specimens underwent tests of bone mineral density. In the foam blocks, 6 tests were conducted for each augmentation combination and also for nonaugmented controls. In the cadaveric testing, 36 lumbar vertebrae were instrumented with a cemented and uncemented control screw to compare features of fixation. Computed tomography (CT) images were taken to assess the geometric profile of the cement plumes in both the foam blocks and the cadaveric vertebrae. RESULTS: In both foam blocks and vertebral specimens, cementation was shown to confer a significant increase in pullout strength. Significant correlations existed between the anterior-posterior and lateral cement plume diameters and pullout strength in cadaveric vertebra and foam blocks, respectively. Within instrumented vertebra, variables such as the width of the vertebral body and screw insertion were found to significantly correlate with enhanced fixation. CT analysis of the instrumented vertebra demonstrated that a centrally distributed pattern of fenestrations was found to result in a cement plume with consistently predictable distribution within the vertebral body, without evidence of leak. CONCLUSION: Cementation of fenestrated pedicle screws increases overall pullout forces; however, there is an unclear relationship between the geometric properties of the cement plume and the overall strength of the screw-bone interface. This study demonstrates that the plume diameter, vertebral body width, and angle of screw insertion are correlated with enhanced pullout strength. Furthermore, varying the fenestration design of injectable screws resulted in a set of predictable plume patterns, which may be associated with fewer complications. Further investigation is required to clarify the optimal geometric and biomechanical properties of injectable pedicle screws and their role in establishing the cement-bone interface. CLINICAL RELEVANCE: This study is relevant to currently practicing spinal surgeons and biomechanical engineers.

Needs assessment for health service design for people with back pain in a hospital setting: A qualitative study.

BACKGROUND: There is a need for effective health service solutions to provide greater structure and support for implementing evidence-based practice in back pain care. Patient involvement in developing these solutions is crucial to increase relevance, acceptability and uptake. OBJECTIVES: To determine patients' perceived needs and barriers to best-practice back pain care, and potential solutions to better address care needs. The study is the third in a series of needs assessment studies feeding into the 'idea generation' for service design in a large teaching hospital in a culturally and linguistically diverse community in metropolitan Sydney, Australia. DESIGN: We conducted a combination of focus groups and in-depth interviews using an interpretive description approach. We used inductive thematic analysis to identify the main themes. SETTING AND PARTICIPANTS: We purposively sampled patients with diverse characteristics from the neurosurgery and physiotherapy outpatient clinics, in particular those whose primary language was English, Arabic, Persian or Mandarin. Non-English audio recordings were translated and transcribed by bilingual researchers. RESULTS: There were 24 participants (focus groups = 9; individual interviews = 15) when data saturation was reached. The analysis identified three key themes with several subthemes around what service designers needed to understand in helping people with back pain in this setting: (1) This is who I am; (2) It's not working for me; and (3) What I think I need. DISCUSSION AND CONCLUSION: This study highlights that perceived unmet needs of patients are underpinned by unhelpful beliefs about the causes of and solutions for back pain, misaligned care expectations, unclear expectations of the hospital role and fragmentations in the health system. To design and implement a service that can deliver better back pain care, several solutions need to be integrated around: developing new resources that challenge unhelpful beliefs and set realistic expectations; improving access to education and self-management resources; focusing on individualized care; using a collaborative multidisciplinary approach within the hospital; and better connecting with and directing primary health care services. PATIENT OR PUBLIC CONTRIBUTION: A consumer representative of the Western Sydney Local Health District provided input during study conceptualisation and is duly recognized in the Acknowledgements section.

A tale of two robots: Operating times and learning curves in robot-assisted lumbar fusion.

Robotic assistance technologies are being incorporated into minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) to minimize radiation exposure to the patient and operating staff. However, they introduce new issues including increased operating time and difficult incorporation into surgical workflow. This study, conducted with 42 patients under the care of one neurosurgeon in Sydney, Australia, investigates the operating time increase with three different robotic modalities, and the learning curves they pose to the surgeon. Between the comparable modalities of freehand MIS-TLIF and Mazor Renaissance® CT to Fluoro, there was a significant increase in time from patient draping to insertion of the final K-wire (p = 0.0019), and a non-significant increase in time per K-wire (p = 0.55) using Mazor Renaissance®. Comparing the ROSA® and Mazor Renaissance® Scan and Plan, there were significant increases in drape to final K-wire time and time per K-wire using ROSA® assistance (p = 0.000068 and p = 0.011). ROSA® also had a steeper learning curve compared to both Mazor Renaissance® modalities, which were similar. Our study shows that Mazor Renaissance® modalities are superior to ROSA® in minimizing extra operating time, and also have easier learning curves; however, both modalities increase operating time compared with freehand MIS-TLIF. This study, to our knowledge, is the first to compare multiple robotic techniques in MIS-TLIF. Though these results highlight important differences between robotic modalities that are crucial for spinal surgeons to understand, the low sample size and variability in data reveal the need for larger, multi-centre studies in this field.

Short research paper: Personal protective equipment for the care of suspected and confirmed COVID-19 patients - Modelling requirements and burn rate.

BACKGROUND: The COVID-19 pandemic has caused unprecedented global demand for personal protective equipment (PPE). A paucity of data on PPE burn rate (PPE consumption over time) in pandemic situations exacerbated these issues as there was little historic research to indicate volumes of PPE required to care for surges in infective patients and thus plan procurement requirements. METHODS: To better understand PPE requirements for care of suspected or confirmed COVID-19 patients in our Australian quaternary referral hospital, the number of staff-to-patient interactions in a 24-h period for three patient groups (ward-based COVID suspect, ward-based COVID confirmed, intensive care COVID confirmed) was audited prospectively from 1st to 30th April 2020. RESULTS: The average number of staff-to-patient interactions in a 24-h period was: 13.1 ± 5.0 (mean ± SD) for stable ward-managed COVID-19 suspect patients; 11.9 ± 3.8 for stable ward-managed confirmed COVID-19 patients; and 30.0 ± 5.3 for stable, mechanically ventilated, ICU-managed COVID-19 patients. This data can be used in PPE demand simulation modelling for COVID-19 and potentially other respiratory illnesses. CONCLUSION: Data on the average number of staff-to-patient interactions needed for the care of COVID-19 patients is presented. This data can be used for PPE demand simulation modelling.

Reduction in Ophthalmic Presentations to Australian Emergency Departments During the COVID-19 Period: Are We Seeing the Full Picture?

PURPOSE: To examine changing patterns of ophthalmic presentations to emergency departments (EDs) during the lockdowns associated with the first wave of the COVID-19 pandemic in Australia and the two months immediately following lockdown relaxation. PATIENTS AND METHODS: This was a retrospective audit of triage coding and ICD-10-AM coding for all patient presentations to four Australian EDs from March 29 to May 31 in 2019 and 2020 (the COVID-19 lockdown period and the corresponding period in 2019), and from June 1 to July 31 in 2019 and 2020 (the post-lockdown period and the corresponding period in 2019). Number of ophthalmic presentations triaged per day and number of seven common and/or time-sensitive, vision threatening ophthalmic diagnoses were examined. Differences in mean daily presentation numbers were assessed with non-paired Student's t-test with Bonferroni correction. RESULTS: Total ophthalmic presentations per day during COVID-19 lockdowns fell by 16% compared to the corresponding period in 2019 (13.0 ± 4.0 in 2019 vs 10.8 ± 3.3 in 2020, mean ± standard deviation; p=0.01). There was also a significant decrease in presentations of atraumatic retinal detachment, conjunctivitis, and eye pain. In the two months following easing of lockdown restrictions, total ophthalmic presentations per day returned to the same level as that of the corresponding period in 2019 (12.2 ± 4.3 in 2019 vs 12.3 ± 4.1 in 2020, p=0.97). CONCLUSION: Total ophthalmic presentations and presentations of atraumatic retinal detachment, conjunctivitis and, eye pain to EDs fell during the lockdowns associated with the first wave of COVID-19 in Australia. These may represent delays in patients seeking appropriate medical attention and may have implications on patient morbidity long after the COVID-19 pandemic.

Using Lean Six Sigma techniques to improve efficiency in outpatient ophthalmology clinics.

BACKGROUND: Increasing patient numbers, complexity of patient management, and healthcare resource limitations have resulted in prolonged patient wait times, decreased quality of service, and decreased patient satisfaction in many outpatient services worldwide. This study investigated the impact of Lean Six Sigma, a service improvement methodology originally from manufacturing, in reducing patient wait times and increasing service capacity in a publicly-funded, tertiary referral outpatient ophthalmology clinic. METHODS: This quality improvement study compared results from two five-months audits of operational data pre- and post-implementation of Lean Six Sigma. A baseline audit was conducted to determine duration and variability of patient in-clinic time and number of patients seen per clinic session. Staff interviews and a time-in-motion study were conducted to identify issues reducing clinic service efficiency. Solutions were developed to address these root causes including: clinic schedule amendments, creation of dedicated postoperative clinics, and clear documentation templates. A post-implementation audit was conducted, and the results compared with baseline audit data. Significant differences in patient in-clinic time pre- and post-solution implementation were assessed using Mann-Whitney test. Differences in variability of patient in-clinic times were assessed using Brown-Forsythe test. Differences in numbers of patients seen per clinic session were assessed using Student's t-test. RESULTS: During the baseline audit period, 19.4 patients were seen per 240-minute clinic session. Median patient in-clinic time was 131 minutes with an interquartile range of 133 minutes (84-217 minutes, quartile 1- quartile 3). Targeted low/negligible cost solutions were implemented to reduce in-clinic times. During the post-implementation audit period, the number of patients seen per session increased 9% to 21.1 (p = 0.016). There was significant reduction in duration (p < 0.001) and variability (p < 0.001) of patient in-clinic time (median 107 minutes, interquartile range 91 minutes [71-162 minutes]). CONCLUSIONS: Lean Six Sigma techniques may be used to reduce duration and variability of patient in-clinic time and increase service capacity in outpatient ophthalmology clinics without additional resource input.

Pullout force of minimally invasive surgical and open pedicle screws-a biomechanical cadaveric study.

BACKGROUND: To assess whether lumbar pedicle screw placement with a minimally invasive surgical (MIS) vs. open technique imparts different biomechanical parameters and thus may affect failure rates. METHODS: Human cadaveric disarticulated lumbar vertebrae 1-5 were stabilised in cement. Pedicle screws were inserted either via the 'MIS' or 'open' technique, based on previously described anatomical landmarks. Each vertebra had one 'MIS' and one 'open' technique screw. Specimens were tested with an Instron mechanical testing machine, positioned to allow for testing of direct coaxial force. Load was applied until failure occurred, and load-displacement curves generated for each screw. RESULTS: Average failure load was found to be 685±399 N for MIS, versus 661±323 N for open technique (P=0.75). The average ultimate failure load was 748±421 N for MIS, versus 772±326 N for open (P=0.74). Average displacement until failure was 0.95±0.49 mm for MIS as compared to 0.95±0.62 mm for open (P=0.996). Axial stiffness was 936±217 N/mm for MIS and 1,016±263 N/mm for open (P=0.19). Average work required to result in failure was 0.84±1.09 J for MIS and 0.82±1.05 J for open (P=0.94). CONCLUSIONS: There was no significant difference in the biomechanical properties of the MIS as compared with open lumbar pedicle screws, when tested until failure under direct coaxial force. The clinical implication may be that there is no significant advantage in the biomechanical properties of MIS versus open lumbar pedicle screw insertion techniques.

Intracranial Arterial Compression of the Anterior Visual Pathway.

Compression of anterior visual pathway (AVP) structures by intracranial arteries is observed not infrequently on neuroimaging. Whether or not such compression results in damage to these structures, however, remains unclear. This information is important to define as AVP compression by intracranial arteries may be a causative factor in patients with otherwise unexplained visual dysfunction. In a single centre, 37 patients with evidence of intracranial artery AVP compression demonstrated on magnetic resonance imaging were identified by retrospective review of case records over the period 2011-2017. Variables were collected, including patient demographics, visual acuity, visual fields, pupillary reactions and optic disc appearance for patients in the case series. Visual field deficits correlated with compression sites in the 37 patients examined. Internal carotid artery-optic nerve compression was the most frequent (unilateral compression n = 9, bilateral compression n = 14), followed by chiasmal compression by the anterior cerebral artery (n = 8) and a combination of optic nerve and chiasmal compression (n = 5). Visual acuity and visual fields were stable on follow-up (mean 4 years) in 24 of 26 cases (93%). We conclude that AVP compression by intracranial arteries may be a causative factor in unexplained visual dysfunction. The visual defects are largely non-progressive.

Primary Choroidal Lymphoma Diagnosed with 27-Gauge Pars Plana Vitrectomy Choroidal Biopsy.

BACKGROUND: Currently, transvitreal fine-needle aspiration biopsy is the most widely used tissue biopsy technique in cases of suspected intraocular lymphoma due to its relative simplicity and low trauma. The small sample produced, however, may be inadequate for diagnostic and prognostic analyses due to mechanical artefacts, insufficient material, or sampling errors. Small case series have demonstrated choroidal biopsy via vitrectomy to be safe and effective. With smaller-gauge vitrectomy instruments, visual recovery is rapid, and post-operative inflammation and conjunctival scarring is minimised. Furthermore, smaller-gauge instrumentation does not appear to affect the diagnostic yield of biopsies for intraocular lymphoma in vitro. We report a case of primary choroidal lymphoma successfully diagnosed with 27-gauge pars plana vitrectomy choroidal biopsy. CASE PRESENTATION: A 72-year-old female presented with a 6-month history of painless blurred vision in her right eye. Fundus examination revealed a large pale choroidal mass centred on the posterior pole with overlying exudative retinal detachment. Enhanced depth imaging optical coherence tomography revealed a markedly thickened choroid with an undulating appearance. B-scan ultrasonography demonstrated diffuse, smooth thickening of the choroid, and retrobulbar extrascleral hypoechoic nodules. A 27-gauge pars plana vitrectomy was performed and choroidal biopsy taken. Histopathologic, immunohistochemical, and flow cytometry studies confirmed a diagnosis of extranodal marginal zone B-cell lymphoma. Systemic workup found no evidence of systemic lymphoma. As such, the patient was diagnosed with primary choroidal lymphoma. She underwent intensity-modulated external beam radiotherapy with subsequent resolution of disease. CONCLUSIONS: Primary choroidal lymphoma can be safely and effectively diagnosed via 27-gauge vitrectomy choroidal biopsy.

Lattice anchoring stabilizes solution-processed semiconductors.

The stability of solution-processed semiconductors remains an important area for improvement on their path to wider deployment. Inorganic caesium lead halide perovskites have a bandgap well suited to tandem solar cells1 but suffer from an undesired phase transition near room temperature2. Colloidal quantum dots (CQDs) are structurally robust materials prized for their size-tunable bandgap3; however, they also require further advances in stability because they are prone to aggregation and surface oxidization at high temperatures as a consequence of incomplete surface passivation4,5. Here we report 'lattice-anchored' hybrid materials that combine caesium lead halide perovskites with lead chalcogenide CQDs, in which lattice matching between the two materials contributes to a stability exceeding that of the constituents. We find that CQDs keep the perovskite in its desired cubic phase, suppressing the transition to the undesired lattice-mismatched phases. The stability of the CQD-anchored perovskite in air is enhanced by an order of magnitude compared with pristine perovskite, and the material remains stable for more than six months at ambient conditions (25 degrees Celsius and about 30 per cent humidity) and more than five hours at 200 degrees Celsius. The perovskite prevents oxidation of the CQD surfaces and reduces the agglomeration of the nanoparticles at 100 degrees Celsius by a factor of five compared with CQD controls. The matrix-protected CQDs show a photoluminescence quantum efficiency of 30 per cent for a CQD solid emitting at infrared wavelengths. The lattice-anchored CQD:perovskite solid exhibits a doubling in charge carrier mobility as a result of a reduced energy barrier for carrier hopping compared with the pure CQD solid. These benefits have potential uses in solution-processed optoelectronic devices.

Radiological outcomes following hyperlordotic cage insertion in anterior cervical discectomy and fusion.

BACKGROUND: Cervical alignment is associated with myelopathy and quality of life. Anterior cervical discectomy and fusion (ACDF) aims to decompress neural structures and optimise cervical alignment. This study examines the quantitative impact of the hyperlordotic 15° ACDF cage on cervical alignment, and compares it to that of the standard lordosis cage. METHODS: A retrospective analysis of radiographical parameters of cervical alignment was conducted in 80 consecutive ACDF patients from two institutions between 2013 and 2017. Forty received 15° cages, 40 received standard cages. Pre- and post-operative Cobb angles and sagittal vertical axes (SVA) were generated from radiographical imaging utilising the SurgimapTM program. Changes in lordosis and SVA were compared within and between groups, and the significance of the change evaluated using the Student t-test. RESULTS: In both groups, post-operative device level, segmental, and global Cobb angles were superior to preoperative values (P<0.05), especially among patients with preoperative kyphosis (P<0.05). Trends suggested greater changes in lordosis in the 15° group, but they did not reach statistical significance (P=0.06-0.23). However, subgroup analyses indicated greater device level Cobb angle change in patients less than 65 yo (P=0.049), and those with preoperative lordosis (P=0.003). Neither standard nor hyperlordotic cages significantly improved SVA in this study. CONCLUSIONS: Hyperlordotic and standard cages both improve cervical lordosis segmentally and globally. Hyperlordotic cages were not shown to be statistically superior to standard cages in this study. Prospective studies featuring consistent imaging modalities are necessary to further delineate their utility.

Rapid "epiretinal membrane" development following intravitreal bevacizumab for Coats' disease.

PURPOSE: To report a case of rapid "epiretinal membrane" ("ERM") development following intravitreal bevacizumab for juvenile Coats' disease. OBSERVATIONS: A 7-year old boy was followed for four years with asymptomatic stage 2 Coats' disease in his left eye. At age 11, he developed symptomatic cystoid macular edema. Argon laser photocoagulation to the leaking aneurysms failed to improve his vision, which had symptomatically declined to 20/30. Four-months after laser, a single injection of intravitreal bevacizumab was given. Rapid development of an "ERM" was noticed on his first post-injection follow-up at 4 weeks. By 8-weeks post-injection the visual acuity had deteriorated to 20/400. 25 + gauge pars plana vitrectomy with "ERM" peeling was performed, with recovery of vision to 20/30 at the 4 months post-operative visit. CONCLUSIONS AND IMPORTANCE: Intravitreal bevacizumab may induce rapidly progressive "ERM" in patients with juvenile Coats' disease.

Preventing brachial plexus injury during shoulder surgery: a real-time cadaveric study.

BACKGROUND: Brachial plexopathy is not uncommon after shoulder surgery. Although thought to be due to stretch neuropathy, its etiology is poorly understood. This study aimed to identify arm positions and maneuvers that may risk causing brachial plexopathy during shoulder arthroplasty. METHODS: Tensions in the cords of the brachial plexuses of 6 human cadaveric upper limbs were measured using load cells while each limb was placed in different arm positions and while they underwent shoulder hemiarthroplasty and revision reverse arthroplasty. Arthroplasty procedures in 4 specimens were performed with standard limb positioning (unsupported), and 2 specimens were supported from under the elbow (supported). Each cord then underwent biomechanical testing to identify tension corresponding to 10% strain (the stretch neuropathy threshold in animal models). RESULTS: Tensions exceeding 15 N, 11 N, and 9 N in the lateral, medial, and posterior cords, respectively, produced 10% strain. Shoulder abduction >70° and combined external rotation >60° with extension >50° increased medial cord tension above the 10% strain threshold. Medial cord tensions (mean ± standard error of the mean) in unsupported specimens increased over baseline during hemiarthroplasty (sounder insertion [4.7 ± 0.6 N, P = .04], prosthesis impaction [6.1 ± 0.8 N, P = .04], and arthroplasty reduction [5.0 ± 0.7 N, P = .04]) and revision reverse arthroplasty (retractor positioning [7.2 ± 0.8 N, P = .02]). Supported specimens experienced lower tensions than unsupported specimens. CONCLUSIONS: Shoulder abduction >70°, combined external rotation >60° with extension >50°, and downward forces on the humeral shaft may risk causing brachial plexopathy. Retractor placement, sounder insertion, humeral prosthesis impaction, and arthroplasty reduction increase medial cord tensions during shoulder arthroplasty. Supporting the arm from under the elbow protected the brachial plexus in this cadaveric model.