Age-related cataracts usually affect both eyes. In most cases, the clouded endogenic lens is replaced surgically with an artificial intraocular lens (IOL), with a few weeks between eye surgeries. However, the cataract surgery can alternatively be performed on both eyes on the same day, with potential advantages and disadvantages.
A recent Cochrane review concluded that, overall, there are unlikely to be any large, clinically important differences between the results of both approaches. However, the quality of evidence of the study results summarized in the systematic review was assessed as moderate to very low. German professional societies still do not recommend the simultaneous bilateral cataract operation.
Advantages and Disadvantages
The potential advantages of simultaneous or immediate sequential bilateral cataract surgery (ISBCS) vs delayed sequential bilateral cataract surgery (DSBCS) include the following points:
In contrast, a possible disadvantage of ISBCS is the risk of both eyes developing postoperative complications simultaneously. In addition, the simultaneous method renders it impossible to use the visual acuity from the first operation for the second operation.
Against this background, the objective of the Cochrane review was to discover whether ISBCS was just as safe, effective, and cost-effective as DSBCS. To do this, they scrutinized 14 studies from nine countries (Canada, United States, United Kingdom, Finland, Sweden, Spain, Czech Republic, Iran, and South Korea) that juxtaposed the results from both methods. The authors of the review compared the studies and assessed the informative value or evidence of the individual studies’ results.
Approximately 276,000 people were included in all the studies, with ISBCS performed on 7400 of them, and DSBCS used on almost 269,000 of them (the vast majority).
Few Differences, Little Evidence
The authors of the Cochrane review reported the most important outcomes, although almost always with the caveat that the evidence was rated as moderate, poor, or very poor. The type of procedure (ISBCS or DSBCS) appeared to make little or no difference to the emergence of endophthalmitis (a rather rare but very feared complication of cataract surgery) within 6 weeks of surgery on one eye. None of the studies reported bilateral endophthalmitis.
Even for other complications that occurred up to 3 months postoperatively, barely any differences were discerned between the two methods, although the quality of evidence was assessed as very poor both for randomized and nonrandomized studies.
Similar results were found (again, with reduced or limited evidence) for the postoperative refraction results and the optimally corrected visual acuity.
With regard to the costs of the procedures, ISBCS was reported to be cheaper, compared with DSBCS, although only one study also found better cost efficiency for ISBCS.
The review authors explained that most of the study results were limited by a small number of endophthalmitis cases overall, variability in assessments of outcomes such as postoperative complications and optimally corrected visual acuity, and a lack of certain data in which the reviewers were interested, among other considerations.
Little Discussed in Germany
“In Germany, there is only very little data on ISBCS because it is barely a topic here,” Thomas Kohnen, MD, PhD, of the University Clinic Frankfurt told Medscape Medical News. Kohnen is chair of the German Commission for Refractive Surgery (KRC), set up by the German Society of Ophthalmology (DOG) and the Professional Association of German Ophthalmologists (BVA).
In Germany, there is little need for ISBCS for multiple reasons. “We have very good medical infrastructure with widespread and prompt ophthalmological care, such that even people living in the countryside do not have to travel great distances or experience long waiting times for a first or second cataract surgery, which is different from many places abroad.”
The cataract surgery in the second eye (in the standard version with implantation of monofocal artificial lenses) is just as well funded by the insurance companies in Germany as the first one, Kohnen said.
Monitor for Complications
Kohnen believes that there are also legal aspects at play in the German ophthalmologists’ reluctance to endorse ISBCS. “The procedure with bilateral operations on the same day is not recommended in the guidelines from our professional societies, [because] any complications that occur postoperatively could potentially entail lengthy legal liability procedures for the surgeons.”
Indeed, serious complications such as endophthalmitis with a risk for blindness are very rare, but also not excluded. “It is of course particularly dramatic if such an event occurs in both eyes at the same time.” Other postoperative visual impairments could develop through cystoid macular edema or through corneal endothelial decompensation, for example.
But possible complications are not the only reason that Kohnen is advocating that specialists first wait calmly for the results of the first cataract operation before commencing the surgery on the second eye. This approach is also particularly relevant for patients who have chosen to have a multifocal or other premium lens implanted. “Patient satisfaction with the new lens is an important topic that may influence their decision for the future lens of the other eye still to be operated on.”
Sequential bilateral cataract surgery with two, mostly outpatient, operations spaced several days to weeks apart is the standard in Germany. Nevertheless, there are exceptions to this procedure in which medical, social, or personal reasons require both eyes to be operated on in a small time window, under general anesthesia in one sitting, or with a gap of one or two nights. These reasons could include, for example, surgery on patients with a disability (such as trisomy 21), congenital childhood cataracts, or in patients under extreme time pressure for the procedure.
The COVID-19 pandemic is also not an argument in favor of ISBCS, said Kohnen. “By implementing a hygiene concept specially designed for COVID-19, at our clinic we were able to treat patients despite the pandemic and continue to ensure the highest level of patient safety and staff protection. In this way, the pandemic didn’t change anything for us since DSBCS continued to be the clear preference over the simultaneous variant of the surgery.”
This article was translated from the Medscape German edition.