Sir,

We welcome the article by Nassiri et al.1 Their paper lends further evidence to the growing body in support of simultaneous bilateral cataract surgery (SBCS).

As Nassiri et al. suggest, the main cited objection to SBCS is the very rarely reported (four cases in the literature) risk of bilateral simultaneous infectious endophthalmitis. Conversely, the advantages of SBCS have been repeated numerous times. We hypothesise a further advantage.

If we assume that a patient undergoing SBCS would have a clinic appointment, a biometry and assessment appointment, surgery, and finally a post-operative visit, these patients would have had four appointments in total. Those undergoing conventional sequential surgery would have the same, followed by their second surgery and a final post-operative visit, totalling six visits. It has been suggested that the average round trip per hospital appointment is 56 miles.2 This would lead to a total of 224 miles per SBCS patient (or 112 000 000 miles for 500 000 patients) and 336 miles per non-SBCS patient (168 000 000 miles for 500 000 patients). It is also suggested that there are 1.48 road fatalities per 100 000 000 miles of road travelled.3 This would lead to a total of 1.66 deaths on the roads per 500 000 patients undergoing SBCS compared with 2.49 deaths for the same number of patients undergoing conventional monocular surgery. This would increase to 2.9 deaths if patients have a second assessment between surgery (thereby totalling seven trips). There is, therefore, potentially 1.5–2 times the risk from death in a road traffic accident by undergoing extra visits for unilateral sequential cataract surgery in those suitable for SBCS. The patients in Nassiri's cohort who cited ‘difficulty in travelling’ as a reason for choosing SBCS may well have been very astute indeed.

In conclusion, the advantages of SBCS are numerous and well documented. The risks and disadvantages are few and sparsely reported. We would recommend that SBCS be considered more frequently for those patients who are suitable.

We challenge your readership with the following question: Which is worse—one case of bilateral simultaneous endophthalmitis or a dead patient from the extra visits for sequential surgery?