Pre-operative assessment for ophthalmic surgery

• A general assessment of a patient's physical and functional health is required as with any pre-assessment, although there are some specific factors which may impact the conduct of anaesthesia

• Patients will be required to lie flat (supra- and infra-orbital ridges in the same plane), or slightly reclined with neck extended, for the duration of their surgery
• Some patients may struggle or be unable to do this:
• Those with significant COPD or cardiac failure
• Those with back pain, spinal or other musculoskeletal deformities
• Those who are obese

• Of course lying supine is only half the story; it's imperative patients can lie still during their procedure lest the diamond-tipped blade (I'm reliably informed they're rather sharp...) or LASER go astray
• Some patients will be unable to stay still for the duration of the surgery e.g.:
• Those with tremors, chronic coughs or movement disorders e.g. Parkinson's disease
• Poorly controlled epilepsy
• Those with significant anxiety or claustrophobia


• Patients with communication issues, confusion or dementia may struggle to comply with instructions, which may also preclude a local/regional technique

• Patients with poorly controlled IHD (or MI within last 3 months) are at increased risk of cardiac ischaemia even under LA
• Poorly controlled HTN (>180/100mmHg) increases complications following ophthalmic surgery, and should trigger consideration of postponing surgery
• Diabetes mellitus is common in this patient population, as it predisposes to cataracts and retinopathy
• Acute blood sugar abnormality (e.g. >17mmol/L or <4mmol/L) should prompt postponement of surgery
• Perioperative hyperglycaemia can lead to sight-threatening complications e.g. choroidal haemorrhage, endophthalmitis and cystoid macular oedema

• Patients with bleeding disorders or thrombocytopaenia may not be suitable for some forms of regional technique
• Clopidogrel or warfarin use:
• Is associated with an increase in minor complications of sharp needle and sub-Tenon's cannula LA infiltration
• Is not associated with an increase in sight-threatening LA complications or operative haemorrhagic complications

• Some ocular factors make regional techniques difficult (enophthalmos, fixed squint) or relatively contra-indicated (axial length >26mm for sharp needle blocks)

• One study of ambulatory surgery found no increase in perioperative events as a result of no pre-operative testing, implying that one could skip this section entirely
• Indeed NICE (2016) recommend against routine testing of ASA 1 & 2 elective patients undergoing elective surgery
• The evidence from a Cochrane review (2018) suggests preoperative testing for cataracts adds expense without any real clinical benefit


• Patients should have, at minimum, a set of standard observations as one would prior to any surgery
• Ensure there is an axial length measured, especially if you are planning to perform a peribulbar or retrobulbar block
• A 12-lead ECG is usually only necessary if the patient is ASA3+ and not had one in the past year, or if there is a heart rate/rhythm or significant blood pressure abnormality
• An INR or APTTr for patients on warfarin or heparin
• A blood sugar for diabetic patients; intra-operative hyperglycaemia should be avoided

• The curriculum mandates we understand "a relatively large proportion of patients requiring ophthalmic surgery are elderly"
• The physiological effects of ageing reduce the functional reserve of all body systems, and anaesthetic considerations in the elderly are described elsewhere
• There are altered pharmacokinetics in elderly patients, who are more sensitive to drugs with sedative effects and dosing should be adjusted accordingly

• There are higher rates of hearing impairment, other communication difficulties, acute confusion and cognitive issues
• These should be elicited to allow informed consent and tailoring of peri-operative plan

• Unfortunately patients with cognitive impairment can end up between a rock and a hard place:
• Loco-regional techniques are probably better, to avoid the neurocognitive decline associated with GA and minimise normal daily rhythm
• Yet these patients may tolerate either the technique or ensuing surgery poorly, meaning a GA may be required to get them through their operation

• The joint RCoA and RCO guidelines suggest agents should be continued for patients undergoing cataract operations as day cases
• Normal therapeutic targets (if applicable) should be maintained
• The risk of significant thrombotic events outweighs the risk of bleeding
• Use of topical anaesthesia ± intracameral injection minimises risk if high therapeutic INR target


• There is a lack of evidence to guide perioperative management for more complex surgery e.g. vitreoretinal surgery, glaucoma surgery, oculopastics
• An MDT approach should be adopted, especially if haemorrhage will compromise surgical outcomes
• For patients on DAPT following cardiac intervention, the normal rules regarding delaying elective surgery apply