Bilateral intraocular surgery has long been a controversial subject of debate among ophthalmologists.1-7 The greatest risk of simultaneous bilateral cataract surgery (SBCS) is bilateral endophthalmitis. Other potential risks include bilateral suprachoroidal hemorrhage, bilateral incorrect IOL power calculation, and bilateral corneal endothelial decompensation. Despite potential complications, SBCS has significant medical, social, and economic benefits. This article discusses the various aspects of SBCS and reviews the antiseptic protocol required to minimize postoperative endophthalmitis.
With improvements in surgical technique, the incidence of postoperative endophthalmitis has significantly decreased, especially transitioning from intracapsular to extracapsular cataract extraction.8 Small-incision phacoemulsification, however, has not resulted in another significant reduction in endophthalmitis rates.9 Previous reported incidences of postoperative unilateral endophthalmitis after SBCS remains low (Table 1). These reported incidences are similar to those reported from unilateral cataract surgery, with incidence of endophthalmitis ranging from 0.05% to 0.3%.10-15 In a literature search, there was only one reported case of bilateral endophthalmitis after SBCS with phacoemulsification.16 The investigators conceded that the surgery was not treated as separate surgeries, because the same fluids were used in flash sterilization of the instruments.
REDUCED HEMORRHAGE RISK
Traditionally, suprachoroidal hemorrhage is a risk associated with regular cataract surgery, although the widespread small-incision phacoemulsification technique has significantly reduced this risk.17
Another argument against SBCS is that dense cataracts may lead to inaccurate biometry when predicting IOL power. Thus, by allowing a delay between the first and second surgery—even in normal cataracts—an adjusted refraction target for the second eye is based on the first. This avoids the potential for refractive surprise in both eyes after bilateral surgery. According to Jabbour et al, there was no improvement in predicting IOL power accuracy in the second eye, after adjusting for the over- or undercorrection in the first.18 Moreover, accuracy to within ±1.00 D or ±2.00 D in postoperative refraction was found to be more than 70% and 95%, respectively.5,19 Refraction difference between two eyes, either less than 0.50 D or 1.00 D, was reported to be 50% and 80%, respectively.19 With the use of (1) accurate biometry (eg, IOLMaster [Carl Zeiss Meditec AG, Stuttgart, Germany]); water immersion, (2) new-generation calculation formulas (eg, Holladay 2 or Haigis), (3) consistent small-incision technique, (4) familiar IOL, and (5) surgeon-adjusted A-constant, one can be accurate, and refraction difference is no longer a concern in SBCS.
MEDICAL ADVANTAGES OF SBCS
Despite the possible risk of bilateral endophthalmitis, performing SBCS has potential advantages. Simultaneous cataract surgery in both eyes allows significantly better visual function compared with separate cataract surgery.20 With better binocular visual acuity, elderly patients also benefit from improved stereopsis, contrast sensitivity, and less glare.5 Patients who underwent cataract surgery in one eye had more difficulty in performing daily activities.6 Generally, it is accepted that SBCS patients required fewer follow-ups and no waiting period for the second eye surgery. This is especially beneficial to patients who are wheelchair-bound or bedridden. There is also better efficiency in operating room usage and fewer outpatient consultations.5,21
Patients achieve faster resumption of daily activities with SBCS versus unilateral cataract surgery. In fact, postoperative visual acuity after bilateral surgery is not significantly different from monocular surgery.7 There is also no significant difference in postoperative refraction between two eyes after simultaneous surgery.5 In one questionnaire on postoperative visual function, 96% of respondents had a positive experience after SBCS, and 91% were willing to recommend bilateral surgery to friends or family.5
To avoid irreparable bilateral corneal damage, surgeons should perform bilateral endothelial cell count preoperatively and use a surgical technique that minimizes endothelial damage (eg, ophthalmic viscosurgical devices [OVD], more chopping, and less ultrasound).
• Postoperative endophthalmitis should be minimized, and a set of standard surgical protocol should be used.2,3,5,6,22-24
• Both eyes must be treated as separate eye surgery. The surgeon and nurse should rescrub and regown for the second eye.
• Second eye surgery must be postponed if complications occurred in the first.
• The second eye must be rescrubbed, and the phaco sets must be from a different sterilization machine. Separate irrigation fluid and instruments must be used.
• The OVD, infusion solution, and IOL should be from different companies and manufacturer to prevent factory contamination.5,24
• Postoperative intracameral antibiotic injection is advocated, although some reservation about its use has been suggested, as certain antibiotics have a toxic effect on the corneal endothelium.
Among the available intracameral antibiotics, gentamicin has been associated with corneal endothelial and retinal damage.25 The recent European Society of Cataract and Refractive Surgeons study indicated that intracameral cefuroxime, administered at the time of cataract surgery, resulted in a fivefold reduction in endophthalmitis.26 Cefuroxime is nontoxic to the corneal endothelium.27 The study group determined that it would be unethical to perform SBSC without the use of intracameral antibiotic. Cefuroxime, however, has been associated with increased bilateral resistance.
Personally, I prefer to use moxifloxacin (Vigamox; Alcon Laboratories, Inc., Fort Worth, Texas) 100 µg in 0.2 mL or 0.3 mL, injected at the conclusion of surgery under the anterior capsule. Have the moxifloxacin 0.5% eyedrop bottle readily available, draw 2 mL of the sterile eyedrop, and dilute it with 8 mL of balanced salt solution, using 0.3 mL for each eye. This antibiotic has the simplest dilution method and avoids potential endothelial toxicity when the wrong concentration is used.
Finally, when considering SBCS, the surgeon must weigh the potential risks against the potential benefits for each individual patient. Bilateral cataract surgery should be performed only if it is in the best interest of the patient, and the risks and benefits must be presented to the patient before surgery.
John Chang, MD, is the Director of the GHC Refractive Surgery Centre at the Hong Kong Sanatorium & Hospital, in Hong Kong. Dr. Chang states that he does not have any financial interest in the products or companies mentioned. He may be reached at johnchang@hksh.com.
Up Front | Mar 2007
Management of Bilateral Cataracts
The benefits associated with a bilateral procedure likely outweigh the risks.
John Chang, MD
