EyeWorld India March 2014 Issue

3 EWAP March 2014 Letters from the Editors Dear Friends 1 t times the areas of concern of our retinal colleagues are worlds apart. Occasionally, however, the orbits of our planets coincide in areas of common interest. This issue of EyeWorld Asia-Pacific considers patients who present with both cataract and significant epiretinal membrane. We have sought a wide range of opinions both from vitreoretinal and anterior segment surgeons. A combined procedure is certainly attractive from a patient’s perspective in that only one operation is required. Scheduling surgery for two surgeons however is complex and there are few surgeons who are highly skilled in both procedures. It is common practice therefore to perform a staged approach with either the cataract or vitrectomy performed as the initial procedure. In circumstances where the cataract is dense enough to preclude adequate visualization or if the epiretinal membrane is of doubtful significance, it makes sense to proceed with cataract surgery as the initial procedure. On the other hand, if the lenticular changes are minor or nonexistent, then vitrectomy and removal of the epiretinal membrane is typically the primary procedure. The anterior segment surgeon is then faced with performing cataract surgery in a post-vitrectomy eye. This poses surgical challenges which are covered in some detail. In my opinion, it is preferable not to delay the cataract surgery unnecessarily as a very brunescent cataract can be difficult in a post-vitrectomy eye. Typically, the chamber can be quite deep and the iris relatively floppy due to lack of support by the vitreous. Paying attention to well balanced fluidics is essential in managing these cases as well as being prepared for the unexpected as there may be zonular or even capsular defects associated with the earlier procedure. If capsular tear occurs during cataract surgery with presentation of vitreous, one can approach vitrectomy either from a limbal or pars plana approach. Certainly, the pars plana approach has advantages and with smaller-gauge vitrectomy and better trochars is a procedure that can be within the domain of anterior segment surgeons. Courses and wetlabs on pars plana vitrectomy for the anterior segment surgeon are increasingly popular. Personally, I still believe that the limbal approach can be equally effective. Separating the infusion and vitrectomy probe is critical in performing a vitrectomy. Using 25-gauge vitrectomy probes allows the surgeon to perform the vitrectomy below the plane of the iris, thus avoiding pulling vitreous anteriorly similar to a pars plana approach. A 25-gauge instrument that can be inserted through a sideport incision is more maneuverable and less disruptive if vitrectomy is required during anterior segment surgery. The ability to perform a limited anterior vitrectomy by the pars planar approach does not encourage anterior segment surgeons to consider more complex posterior segment procedures such as dealing with a dropped nucleus which should remain the domain of the expert vitreoretinal surgeon. Finally, if vitrectomy is required, one of the difficult areas in the past has been determining whether all remaining strands have been removed. There is no doubt that intracameral triamcinolone is of great benefit in this situation and the articles in this issue contain valuable advice on the correct use and preparation of triamcinolone in these circumstances. Although the anterior vitreous is not a region where the anterior segment surgeon typically chooses to venture, occasionally it is necessary, particularly with the management of trauma and anterior segment reconstruction. I hope this issue is helpful when these difficult cases are encountered. Warmest regards Graham Barrett Chief Medical Editor EyeWorld Asia-Pacific Dear Friends D here is no doubt that cataract surgery is evolving from an ultrasound-based surgery to a laser- based one, but the femtosecond laser may not be the clear winner here. A nano laser has emerged to add another laser option to the cataract surgery armamentarium. It appears that combining femtosecond laser with intraoperative aberrometry results in a much higher percentage of eyes within 0.5 D of emmetropia than manual procedures, and can virtually eliminate the need for ultrasound in all cataracts. Femtosecond laser-assisted cataract surgery (FLACS) is a recent advancement in cataract surgery that offers an attractive new option for performing accurate and reproducible anterior capsulotomies, lens fragmentation, refractive keratotomies, and clear corneal incisions. Although prior studies have reported the potential advantage of this technique over traditional phacoemulsification cataract surgery, few have reported on the safety of this new technology. As novel techniques are developed, it has been postulated that FLACS will allow for safer removal of nuclear fragments with less manipulation in the eye and less phacoemulsification energy. It is conceivable that this technology has the potential to increase the safety of cataract surgery in patients with weakened zonular fibers, trauma, or abnormal anterior chamber anatomy due to less manipulation of nuclear fragments. New ways of measuring posterior corneal astigmatism have been demonstrated to have a role in residual astigmatism after toric IOL implantation. Patients who have with-the-rule astigmatism are often overcorrected, while patients who have against- the-rule astigmatism are often undercorrected when posterior corneal astigmatism is not accounted for. Improvements in toric calculators could be an important future innovation in the topic. IOL power calculators would most likely measure total corneal power, taking the front and back surfaces into account. Technology has made our lives simpler and taken accuracy in vision care to staggering heights. My customary closure is with a couplet from the sage poet, Tiruvalluvar, who lived 2,000 years ago: Wisdom is to live in tune with the mode of the changing world. A man of true knowledge understands how the world moves, and moves acoordingly. - Tirukkural 426 Warmest Regards, S. Natarajan, MD Regional Managing Editor EyeWorld Asia-Pacific