EyeWorld Asia-Pacific September 2014 Issue

12 September 2014 EWAP FEAturE continued on page 14 Experts - from page 11 Views from Asia-Pacific CHAN Wing Kwong, MD Visiting Consultant, Singapore National Eye Centre 11 Third Hospital Avenue, Singapore 168751 Eye & Retina Surgeons #13-03 Camden Medical Centre, 1 Orchard Boulevard, Singapore 248649 Tel. no. +65-6738-2000 Fax no. +65-6738-2111 wkchan@me.com S urgeons today promise spectacle freedom after cataract surgery withmultifocal, accommodating, and toric IOLs. And patients expect it. Unfortunately, even with the best methods and formulae used in IOL biometry, there are still about 10% of eyes that are more than 1 D from the predicted refractive error. This occurs more frequently in patients with abnormally long and short axial lengths, intumescent or dense cataracts, and in those after previous corneal refractive surgery. Recognizing these patients and setting the stage with an appropriate expectation is the first step to avoiding a refractive disappointment after cataract surgery. If the patient is satisfied with the result, whatever the refractive error, you won’t have to do more. Remember to “treat the patient, not the refraction”. Spectacles and contact lenses are the obvious first choice to correct the refractive error. If these are rejected or inappropriate for the patient, laser vision correction is an accurate, safe, and predictable means to achieve the intended refractive result. PRK and LASIK are both effective procedures to correct the typically low refractive errors encountered in such patients. I do not think that there needs to be a discussion on whether PRK or LASIK is the better procedure to undertake for a cataract surgeon who is a novice in refractive surgery. I doubt if a cataract surgeon wants to deal with potential delayed corneal epithelial healing and corneal haze after PRK or flap striae, flap displacement or epithelial ingrowth after LASIK in an already unhappy patient. If the cataract surgeon is inexperienced in refractive surgery, he will serve his patients and himself best by referring these dissatisfied patients to a refractive surgeon. Editors’ note: Dr. Chan has no financial interests related to his comments. John S. M. CHANG, MD Director, Guy Hugh Chan Refractive Surgery Centre Hong Kong Sanatorium and Hospital 8/F Li Shu Pui Block, Phase II 2 Village Road, Happy Valley, Hong Kong Tel. no. +852-2835-8885 Fax no. +852-2835-8887 johnchang@hksh.com T here is no doubt PRK is significantly safer for the occasional user because there are fewer flap problems to be concerned with or deal with; however, LASIK is the preferred procedure because of faster recovery and much easier and more convenient further enhancements (if necessary) because even though small amounts of refraction are being corrected, the surgery is not always absolutely accurate. If LASIK is chosen by the infrequent user, one must use the IntraLase because the microkeratome requires a lot of surgical experience. Although surface ablation is much easier to perform, it runs a higher risk of infection; however, this only applies for the first few days. Once the epithelium has healed, the eventual vision and recovery is the same. There is also a lower risk of ectasia in borderline cases. It is advisable to routinely perform videokeratography on these patients before cataract surgery in case there are any cornea problems, e.g. forme fruste or frank keratoconus that prohibits further LASIK or PRK touch up. When taking a course for certification, it is extremely important for the surgeon to know what can and cannot be done. As for the cataract surgery, it is preferable to err on the myopic side because myopic astigmatism correction is more accurate than hyperopic astigmatism1. Also, patients with some residual myopia at least can see intermediate distance and near. Reference 1. Ivarsen A, Næser K, Hjortdal J. Laser in situ keratomileusis for high astigmatism in myopic and hyperopic eyes. J Cataract Refract Surg. 2013 Jan;39(1):74-80. Editors’ note: Dr. Chang is a consultant for Abbott Medical Optics and receives travel support from Technolas Perfect Vision. much shorter for LASIK than PRK, and these are already dissatisfied patients. Intentionally adding a longer healing time may not make sense in every case and LASIK may be a better choice, he said. Conversely, a general ophthalmologist or cataract surgeon without refractive training or a great deal of refractive surgical experience might be better served by performing PRK, said Uday Devgan, MD , in private practice in Los Angeles, Calif., U.S., and chief of ophthalmology, Olive View-UCLA Medical Center, Los Angeles, Calif., U.S. “PRK is very accurate, very safe, and has a minimal learning curve,” he said. “The results are excellent, particularly since these post-cataract surgery patients typically have very small residual refractions to treat, somewhere around 1 to 1.5 D—unlike doing primary PRK or LASIK in young non-cataract patients where you may be treating –6 D or –8 D.” Both PRK and LASIK have short learning curves, Dr. Hoffman said, but agreed that LASIK may be more intimidating for the novice. “There are nuances to lifting the flap, and the potential complications of epithelial ingrowth, diffuse lamellar keratitis, or folds can be daunting,” he said. “PRK eliminates those potentials.” Identifying the risk/ safety profile Regardless of refractive surgical experience, Dr. Hoffman cautions surgeons to be wary when correcting residual refractive errors, and added that some physicians advocate only a 6- to 8-week waiting period before performing LASIK. “For me, the ease of the PRK procedure makes this my go-to technique 90% of the time,” he