Retinal artery occlusion after ophthalmic surgery under regional anaesthesia: A narrative review.

Two recent cases of central retinal artery occlusion under otherwise uncomplicated sub-Tenon's block that resulted in significant visual loss after cataract surgery prompted us to undertake a literature review of such cases. We identified 97 cases of retinal artery occlusion after ophthalmic surgery under regional anaesthesia that had no immediate signs of block-related complications. These occurred after various intraocular (87%) and extraocular (13%) operations, across a wide range of ages (19-89 years) on patients with (59%) or without (39%) known risk factors. The anaesthetic techniques included 40 retrobulbar blocks, 36 peribulbar blocks, 19 sub-Tenon's blocks, one topical anaesthetic and one unspecified local anaesthetic. Different strengths of lidocaine, bupivacaine, mepivacaine and ropivacaine, either alone or in various combinations, were used. The details of the anaesthetic techniques were often incomplete in the reports, which made comparison and analysis difficult. Only nine cases had their cause (optic nerve sheath injury) identified, while the mechanism of injury was unclear in the remaining patients. Various mechanisms were postulated; however, the cause was likely to be multifactorial due to patient, surgical and anaesthetic risk factors, especially in those with compromised retinal circulation. As there were no definite risk factors identified, no specific recommendations could be made to avoid this devastating outcome. We have provided rationales for some general considerations, which may reduce this risk, and propose anaesthetic options for ophthalmic surgery on the fellow eye if required, based both on our literature review and our personal experience.

Custom designed and 3D-printed titanium pelvic implants for acetabular reconstruction after tumour resection.

BACKGROUND: Reconstructive procedure following resection of large pelvic tumours around the hip joint remains a complex challenge. METHODS: This study presents a retrospective case series of patients presenting with benign or malignant pelvic tumour for which an internal hemipelvectomy including the hip joint and subsequent reconstruction with a custom designed 3-dimensional printed titanium pelvic implant (3DPPI) has been performed between August 2013 and January 2018. RESULTS: 15 consecutive patients with a median age of 33.9 years (IQR 26.4-72.2) and a median BMI of 20.7 kg/m2 (IQR 19.0-33.3) were reviewed after median follow-up of 33.8 months (IQR 24.0-78.1). The majority of patients presented with a malignant tumour as their principal diagnosis (n = 13, 86.7%). The median surgical time was 5.5 hours (IQR 4.5-8.5) and median peri-operative blood loss was 5000 ml (IQR 2000-10000). The median MSTS score at follow-up was 63.3% (IQR 51.7-86.7%). The median NRS in rest was 0.0 (IQR 0.0-5.0), the median NRS during activity was 2.0 (IQR 0.5-7.0) and the median HOOS-PS was 76.6% (IQR 67.9-91.0). 4 patients had implant-specific complications (n = 4, 26.6%); 1 hip dislocation (Henderson type 1a), 3 structural complications (type 3a), 1 deep infection (type 4a) and 1 local tumour recurrence (type 5b). At follow-up, 4 out of 15 implants were classified as a failure, resulting in an implant survival rate of 73.3%. CONCLUSIONS: Acceptable peri-operative outcomes, functional results, complication rates and short-term implant survival can be achieved in a cohort of complex patients undergoing 3DPPI reconstruction after hemipelvectomy including the acetabulum.

Comparison of Primary Duet Lens Procedures: In-The-Bag Monofocal with Sulcus Multifocal, and Standard Single Multifocal Lens for Cataract Surgery.

Purpose: To assess the safety and efficacy of primary duet intraocular lens (IOL) procedure using an in-The-bag monofocal IOL and a sulcus-based multifocal reversible platform for cataract surgery. The visual outcomes were compared with a single in-The-bag multifocal IOL. Patients and Methods: Retrospective cohort study. Consecutive patients who underwent primary duet IOL procedures were compared with consecutive patients who underwent single multifocal IOL surgery. Primary outcomes were uncorrected distance and near visual acuities (UDVA and UNVA), refraction and spherical equivalent data. Secondary outcomes included surgical complications. Results: The study group consisted of 32 eyes (22 toric IOLs) whilst the control group had 57 eyes (29 toric IOLs). There were no statistically significant differences between the two groups on post-operative 1-month and 1-year UDVA (p=0.1522 and 0.4926, respectively) and UNVA (p=0.1248 and 0.2738, respectively). There were no statistically significant differences in the postoperative 1-month spherical equivalent within ± 0.5 diopter (p=0.1891). Postoperative intraocular pressure spikes were observed on day-1 in both groups, with most returned to their baseline at 1-month and all were normal at 1-year post surgery. There were no statistically significant differences in intraocular pressure between the two groups on day-1, 1-month and 1-year after surgery (p=0.6421). There were no statistically significant differences in the IOL axis deviation from the intended axis in the toric subgroup analysis (p=0.5843). Conclusion: Primary duet IOL procedure is equally effective and safe in correcting distance and near vision when compared with single multifocal IOL in the capsular bag.

Anaesthetic considerations for the surgical management of ocular hypotony in adults.

Ocular hypotony can occur from many causes, including eye trauma, ophthalmic surgery and ophthalmic regional anaesthesia-related complications. Some of these patients require surgical intervention(s) necessitating repeat anaesthesia. While surgical management of these patients is well described in the literature, the anaesthetic management is seldom discussed. The hypotonous eye may also have altered globe anatomy, meaning that the usual ocular proprioceptive feedbacks during regional ophthalmic block may be altered or lost, leading to higher risk of inadvertent globe injury. In an 'open globe' there is a risk of sight-threatening expulsive choroidal haemorrhage as a consequence of ophthalmic block or general anaesthesia. This narrative review describes the physiology of aqueous humour, the risk factors associated with ophthalmic regional anaesthesia-related ocular hypotony, the surgical management, and a special emphasis on anaesthetic management. Traumatic hypotony usually requires urgent surgical repair, whereas iatrogenic hypotony may be less urgent, with many cases scheduled as elective procedures. There is no universal best anaesthetic technique. Topical anaesthesia and regional ophthalmic block, with some technique modifications, are suitable in many mild-to-moderate cases, whilst general anaesthesia may be required for complex and longer procedures, and severely distorted globes.

Practical Considerations for Dexmedetomidine Sedation in Adult Cataract Surgery Under Local/Regional Anesthesia: A Narrative Review.

Cataract surgery is predominantly performed under local/regional anesthesia, with or without sedation. The practice pattern of sedation is unknown and seems to vary significantly among institutions and countries, routinely administered in some parts of the world to the other extreme of none at all. The selection of sedative agents and techniques varies widely. Currently, there is no ideal sedative agent. Dexmedetomidine has gained recent attention for sedation in ophthalmic local/regional anesthesia due to its alleged advantages of effective sedation with minimal respiratory depression, decreased intraocular pressure, and reduced pain during the local anesthetic injection; however, they are subject to differing interpretations. Published literature also suggests that although dexmedetomidine sedation for cataract surgery under local/regional anesthesia is potentially useful, its role may be limited due to logistical difficulties in administering the recommended dose.

Sub-Tenon's anaesthesia for modern eye surgery-clinicians' perspective, 30 years after re-introduction.

Sub-Tenon's block (STB) is a good technique of local anaesthesia for many types of eye surgery. It has a relatively good risk profile, in that sight- and life-threatening complications appear to be extremely rare. STB has gained popularity in the last three decades, with refinements including different types of blunt metal cannula, plastic cannulae and 'incisionless' approaches. Usage of STB varies significantly across the globe. This narrative review documents the historical evolution of STB techniques, anatomical and physiological considerations, its utility and suitability, complications, explores the current practice and possible future applications.

Anesthesia Considerations for Cataract Surgery in Patients with Schizophrenia: A Narrative Review.

Schizophrenia is ranked among the top 10 global burdens of disease. About 1% of people meet the diagnostic criteria for this disorder over their lifetime. Schizophrenic patients can develop cataract, particularly related to age and medications, requiring surgery and anesthesia. Many concerning factors, including cognitive function, anxiety, behavioral issues, poor cooperation and paroxysmal movements, may lead to general anesthesia as the default method. Antipsychotic agents should be continued during the perioperative period if possible. Topical/regional anesthesia is suitable in most schizophrenic patients undergoing cataract surgery. It reduces potential drug interactions and many postoperative complications; however, appropriate patient selection is paramount to its success. General anesthesia remains the primary technique for patients who are considered unsuitable for the topical/regional technique. Early involvement of a psychiatrist in the perioperative period, especially for patients requiring general anesthesia, is beneficial but often under-utilized. This narrative review summarizes the anesthetic considerations for cataract surgery in patients with schizophrenia.

Anaesthesia for ophthalmic procedures in patients with thyroid eye disease.

Thyroid eye disease is an autoimmune inflammatory disorder of the orbit in adults. It causes inflammation, expansion and fibrosis of orbital fat, muscles and the lacrimal gland, leading to facial disfigurement, functional disability and, in severe cases, blindness. Overall, approximately 20% of affected patients need some form of surgical intervention requiring anaesthesia. This narrative review explores the background of thyroid eye disease, surgical procedures performed and their implications for anaesthesia. General anaesthesia is used for orbital decompression procedures, strabismus correction surgery and complex oculoplastic procedures. Local anaesthetic infiltration or regional anaesthesia under monitored anaesthesia care are the techniques most commonly employed for eyelid retraction surgery. It is important to limit the volume of local anaesthetic agent used during infiltration and continuously monitor the orbital volume and ocular pressure with a ballottement technique. In addition, the contralateral eye should be checked and, if necessary, protected against corneal exposure. Retrobulbar, peribulbar and sub-Tenon's blocks are best avoided. Topical anaesthesia has been used for some strabismus correction surgery but its use is limited to motivated and cooperative patients only.

Anaesthetic considerations for strabismus surgery in children and adults.

Strabismus correction surgery is the most common eye operation in children. Adults have approximately a 4% lifetime risk of developing strabismus. Current treatment options include pharmacological injection of botulinum toxin or bupivacaine, conventional corrective surgery, adjustable suture surgery and minimally invasive surgery. Repeated surgery is common as each operation has a 60%-80% chance of successful correction. The benefits of early surgical correction in large-angle strabismus in children outweigh the risks of anaesthesia. General anaesthesia is suitable for patients of all age groups, for complicated or repeated surgery, and bilateral eye procedures. Regional ophthalmic block reduces the incidence of oculocardiac reflex and emergence agitation, and provides postoperative analgesia, but requires a cooperative patient as many experience discomfort. Topical anaesthesia has been used in pharmacological injection, minimally invasive surgery, uncomplicated conventional strabismus surgery and some adjustable suture strabismus surgery. Its use, however, is only limited to cooperative adult patients. Prophylactic antiemesis with both ondansetron and dexamethasone is recommended, especially for children. A multimodal analgesia approach, including paracetamol, intravenous non-steroidal anti-inflammatory drugs, topical local anaesthetic and minimal opioid usage, is recommended for postoperative analgesia, while a supplementary regional ophthalmic block is at the discretion of the team.