EyeWorld India March 2015 Issue

3 EWAP CONTENTS March 2015 Dear Friends W ith the increased rate of postoperative infection, attention needs to be paid to surgical asepsis, particularly in the incision management. It has been noted that paracentesis and corneal transplants are at decreased risk for infection and clear corneal cataract incisions are known to present with a greater risk for endophthalmitis. What could be the probable factors leading to this increase in risk for infection after clear corneal incision (CCIs)? One of the theories suggests that altered wound stability immediately after the surgery may lead to ocular hypotony. Due to the deformed corneal incisions and resulting pressure gradient there is further wound leak and hypotony. This provides a route for bacterial entry into the anterior chamber. An important issue regarding the prevention of postoperative endophthalmitis is the use of intracameral antibiotics. There have been several reports of a decreased incidence of endophthalmitis after using dilute antibiotic agents in the irrigating solution. In 2007, the ASCRS Cataract Clinical Committee did a survey regarding endophthalmitis antibiotic prophylaxis practice patterns. The results of the study had shown a five- fold reduction in the rate of endophthalmitis with the use of intracameral injection of cefuroxime at the completion of the cataract surgery. It has been noted that with the appropriate use of aseptic methods, careful chemoprophylaxis, and CCI design and sealing, risks for infection should be acceptably low. Hope you have great time reading this issue of our journal. The Tamil poet and sage Tiruvalluvar, who lived 2,000 years ago, has rightly said: If the mind is free from bias, The words uttered are bound to be fair. - Tirukkural 119 Warmest Regards, S. Natarajan, MD Regional Managing Editor EyeWorld Asia-Pacific Letters from the Editors Dear Friends T he occurrence of endophthalmitis after cataract surgery remains our deepest fear. In this issue we discuss the various options for prophylaxis and in particular examine the use of intracameral antibiotics. The landmark study performed by ESCRS several years ago clearly showed a benefit from the prophylactic use of intracameral antibiotics and their use is common practice in Europe and the Asia-Pacific. Recent surveys in the U.S. show an increasing trend to using intracameral antibiotics but the usage remains significantly less in other regions. This is partly related to the lack of commercially available preparations of cefuroxime and surgeons’ concern about the potential for TASS from improperly prepared formulations. Nevertheless direct injection of moxyfloxacin prepared from topical Vigamox (Alcon, Fort Worth/ Hünenberg, Switzerland) is used quite frequently in the U.S. as an alternative. Personally, I had been using antibiotics in the infusion, either vancomycin alone or combined with gentamycin, for many years prior to the recent popularity of intracameral cefuroxime, although there are theoretical reasons why direct injection may be preferred there are many surgeons who successfully use this strategy for prophylaxis and the broad spectrum is attractive. The numbers required for direct comparison of different modes of delivery of intracameral antibiotics as well as different formulations are enormous and it is unlikely that further study will be carried out. Individual surgeons therefore have to make their choice based not only on evidence but their experience in preventing this most serious complication. Although much rarer than endophthalmitis, unexpected refractive outcomes are far more frequent. The challenges of unusually short and long eyes have largely been addressed with modifications of axial length and newer formulae. Toric lenses are particularly challenging as one has to consider the magnitude and axis of the required cylinder correction in addition to the spherical equivalent power. The role of the posterior cornea has largely been ignored in calculations and this can be addressed by regression-based nomograms or direct measurements with devices capable of measuring the posterior cornea. An alternative is the calculator I have developed, which contains an integral calculation of the posterior cornea providing a greater predictability with toric intraocular lenses. The toric cam app and axis marker I have developed are a simple but effective solution to improving alignment of intraocular lenses on the correct axis and I hope our readers will find both the calculator and toric cam approach helpful in their practice. Warmest regards Graham Barrett Chief Medical Editor EyeWorld Asia-Pacific