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.

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.

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.