Sir,

I was interested to see Nair and Rimmer's report of ‘side-saddle’ positioning for phacoemulsification in patients who are unable to lie flat.1 I have been using a virtually identical technique for the last 2 to 3 years,2, and I suggest some refinements. Topical-intracameral anaesthesia allows the patient to fixate the operating light and therefore keep the eye still, in the desired position, with a good red-reflex. Surgery may be further facilitated by a face turn, and/or chin-up head positioning, if the patient is able to do this. With these adjustments, it is usually easy to make an on-axis incision, which may be inferior, temporal, or nasal, as required. Sometimes it is more comfortable for the surgeon to stand rather than to sit, facing the patient. The more upright the patient, the more the operating microscope must be turned towards the horizontal, and consequently the surgeon's arms will be more outstretched. With more extreme positioning, the outstretched arms can make surgery feel less controlled than normal: in these cases, I prefer to use a ‘divide and conquer’ technique with a straight second instrument, rather than risk iris trauma with an angled chopper. My personal practice is to use the ‘standing-temporal approach’3 for most patients who cannot lie flat, and to reserve ‘side-saddle’ positioning for those who cannot adopt the required ‘face to ceiling’ position, or who need an inferior incision for astigmatism.

To illustrate the usefulness of the technique, I presented two of my patients to the ‘difficult cases' discussion’ at the 2007 annual meeting of the British Ophthalmic Anaesthesia Society. Both patients had severe Meniere's disease. The first, aged 83, needed seven pillows to sleep, would vomit if laid flatter, and had a previous cardiac procedure performed in the sitting position because of this. She also had angina, diabetes, and a hiatus hernia. The second patient, aged 82, would vomit and also have diarrhoea if laid flat (this is a recognised feature of Meniere's disease). She slept upright and also suffered from back pain and anxiety. The assembled audience of around 70 ophthalmic anaesthetists and ophthalmologists was unable to suggest any other safe approach to cataract surgery in these patients. Both of these patients had uneventful ‘side-saddle’ phacosurgery using topical-intracameral anaesthesia: the first had an on-axis infero-temporal incision with the patient seated almost upright (80° above the horizontal), and the second with an on-axis inferior incision, with the chair-back at 50° above horizontal. Both patients remained comfortable with no vomiting or other problems.

I agree that this technique can be very useful for those patients for whom the conventional positioning is not possible. It is not always as easy as phacoemulsification with the patient in the standard position, so it should only be attempted by the experienced surgeons.