We agree with many of the comments of the International Society of Bilateral Cataract Surgeons (iSBCS) and welcome the debate regarding what is best practice for patients and society.1 However, many of the arguments made in this response have already been made in the ‘Bilateral same-day cataract surgery should routinely be offered to patients – Yes’ article,2 accompanying our No argument.3

First, the common ground. We agree that there may be circumstances where immediate sequential bilateral cataract surgery (ISBCS) is in the best interests of the patient. We also agree that surgeons should not be financially penalised for ISBCS. When we state that interest in ISBCS is fuelled by potential economic benefits, it is the economic benefits for the social system as a whole to which we refer.

We also agree that the publications we reference show some medical benefit of ISBCS, however our argument is that the medical benefits are primarily transient if second eye surgery is performed. For example, attainment of normal stereopsis and binocular summation of visual acuity may be achieved more quickly with ISBCS but will also be achieved with an interval between surgeries. We are not aware of any publications discussing ISBCS that do not also discuss convenience and economy, and these issues are rightly discussed in our article.

We do not agree that other bilateral ocular procedures should be used as a model for ISBCS. It is perhaps misleading to liken ISBCS to bilateral ptosis or squint surgery, and even to bilateral retinal surgery, where the risk benefit ratios may be quite different to cataract surgery.

We agree that the evidence regarding potential risk factors for endophthalmitis is limited. However we prefer to err on the side of caution and treat patients’ blepharitis prior to cataract surgery. Furthermore, the question of risk factors for endophthalmitis affects the suitability of an individual patient for ISBCS more than the wider debate, as to whether ISBCS is appropriate in the first place.

The authors refer to the waiting time for cataract surgery, which varies from region to region. A long wait between first and second eye cataract surgery is not ideal. However, if ISBCS were to be widely adopted, it is conceivable that the waiting time for first eye cataract surgery may actually increase due to the additional time required for the bilateral surgical procedure.

Mention is also made of the low incidence of endophthalmitis following ISBCS, however, much of this evidence is retrospective. A previous paper based on a survey of ISBCS surgeons stated that as ‘each case represented a memorable event for the surgeon and it is unlikely that omissions were made in data collection’.4 When introducing a new procedure into practice a more robust prospective evaluation would be better.

The precautions recommended by the iSBCS to reduce the risk of endophthalmitis should be commended, however, as they state, most cases of endophthalmitis emanate from the patient’s own flora. Therefore measures such as re-gloving, re-gowning, and using devices from different manufactures or batches may not prevent infection. By operating on both eyes at the same sitting it is logical that there is a potential increase in risk, particularly from sources such as airborne exposure in the operating theater.

We recognize that endophthalmitis does not equate to blindness, but it is a frequently devastating and best-avoided condition. Also, the argument against ISBCS is not one purely based on endophthalmitis, for example, deferring second eye surgery allows one to know the refractive results of the first eye and adjust IOL selection for the second.

We agree that ISBCS should be offered to appropriate patients, however, we disagree on the definition of appropriate. We recommend that ISBCS be offered to patients with a definite indication for ISBCS and not purely for those without a contraindication.