EyeWorld India June 2019 Issue

EWAP JUNE 2019 3 EDITORIAL T he theme of our June issue of EyeWorld ƂÃ>*>VwV is the Refractive Cataract. As expected, the issue discusses in depth the many different options available to address and improve refractive outcomes after cataract surgery and intraocular lens implantation, including addressing the presbyopic needs of patients. Options for the latter range from modest monovision to trifocals and the different types of implants are covered in detail. One of the more challenging issues that we deal with in relation to the “Refractive Cataract” is the increasing number of patients who have had previous refractive surgery and now require cataract surgery. These patients have been accustomed to good unaided vision and therefore are particularly sensitive to the issue of requiring spectacle correction following cataract surgery. Historically, the refractive outcome in patients undergoing cataract surgery after PRK, LASIK or RK has been relatively unpredictable. Attempts to improve prediction are focused on improved formulae, new technology for more precise biometry, and the ability to measure additional parameters altered by the refractive procedure. One of the formulae available for this purpose is the “True K Formula” which is available on the APACRS website (www.apacrs.org) . This formula can be used for patients who have had previous myopic, hyperopic LASIK/PRK or RK and contains an integrated algorithm to address the double K issue. More recently, ÃÜi«ÌÃÕÀVi " / `iÛViÃ >` -Vi«yÕ} Ì}À>«iÀÃ >Ài >Li Ì i>ÃÕÀi the posterior cornea. The altered ratio of the posterior cornea to the anterior cornea is one of the fundamental reasons for unexpected outcomes after previous refractive surgery. If this measurement is taken into account, then the prediction accuracy of formulae could potentially improve in this context. In May this year, I updated the online version of the True K toric calculator to version 2.0. This version allows the use of the actual measured posterior cornea to be utilized as an alternative to the predicted posterior cornea in calculating the required lens for patients who have undergone previous refractive surgery. In a retrospective analysis using swept-source OCT (IOLMaster 700), the predicted outcome using the True K formula with the measured posterior cornea proved to be more accurate than the outcome using standard Ks. The data was presented at the ASCRS meeting in San Diego and personally I now always take into consideration the predicted outcome using the measured posterior cornea as well as the predicted posterior cornea, with and without the history of the change in refraction associated with the refractive procedure. In addition, the “True K toric Calculator” has also been updated to version 2.0. A standard calculator is not appropriate for predicting the required toric IOL after previous refractive surgery and I developed the True K toric calculator Ã«iVwV>Þ vÀ ÌÃ «ÕÀ«Ãi° With version 2.0, the True K toric calculator can also utilize the measured posterior cornea and once again this does appear to provide improved accuracy for toric IOL prediction, prediction after cataract surgery. Version 2.0 of the True K toric calculator also includes the K calculator to provide an integrated K from multiple devices. /Ã ÃÌÀi>iÃ Ìi ÜÀyÜ `iÌiÀ} LÌÃ«iÀV> >` ÌÀV ÕÌViÃ in patients who have had previous refractive surgery. «i Ài>`iÀÃ Ü w` Ìi Õ«`>Ìi Ì Ìi /ÀÕi >` /ÀÕi ÌÀV V>VÕ>ÌÀ helpful in determining the correct IOL for their patients who have undergone previous refractive surgery and of interest in this issue of the “Refractive Cataract.” EWAP The Refractive Cataract Graham Barrett Chief Medical Editor EyeWorld ƂÃ>*>VwV T he new issue v ÃViÌwV>Þ enriched EyeWorld Asia- 2CEKƂE is out for the month of June 2019 with fascinating articles. Our cover features deal with innovative methods of refractive corrections. New FDA- approved parameters have taken SMILE to the next level. Now refractive surgeons can make room for the toric ICL in their toolbox. There is an interesting article on premium IOLs, IOLs that continue to gain popularity. There is also an informative article about considerations for patients with prior corneal refractive surgery. Surgeons identify the key to earlier diagnosis of keratoconus patients with advanced imaging. In the complicated glaucoma cases section, read our >ÀÌVi Ì Ü >LÕÌ L>>V} Ìi ÀÃÃ >` LiiwÌÃ of continuing anticoagulant therapy perioperatively in glaucoma surgeries. Surgeons will familiarize you with the different ways of managing the corneal endothelium during glaucoma surgery. In the cataract section, “Up to the challenge” will help you to deal with rock-hard cataracts. Experts discuss extended depth of focus IOLs in-depth and challenge their use in non-routine cases. The article on FLACS addresses its international perspective in premium practice. In our refractive surgery section, we revisit monovision by IOLs with the trend of less anisometropia for better outcomes. There is an in-depth discussion about advantages of a split bifocal IOL. Read an exciting article about a surgeon’s experience with small aperture implants. In our glaucoma section, an expert discusses his early experience with the XEN implant. The potential v > VÌ>VÌ iÃ ÃiÃÀ >ÃÃiÃÃ} Ìi ivwV>VÞ v IOP-lowering interventions is an interesting take. One surgeon describes how trabeculectomy holds its ground for providing reliable IOP reductions in glaucoma patients. In our device focus, trifocal IOLs providing near, intermediate, and distance vision are addressed. It is exhilarating to imagine the future of IOP-monitoring devices with our article. The pharmaceutical focus highlights the use of NSAIDs for cataract surgery. Finally, we conclude this issue with new insight on how blue light may damage eyes. As always, I end with insight from the Tirukkural : Whatever whoever may say, listen to it, And Wisdom is to comprehend the true meaning of it. ( Tirukkural, Chapter 43, Quote 423) S. Natarajan, MD Regional Managing Director EyeWorld ƂÃ>*>VwV