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16 EW SHOW DAILY Tuesday, April 23, 2013 ASCRS Symposia Angle closure A to Z by Chiles Aedam R. Samaniego EyeWorld AP Senior Staff Writer W Reay H. Brown, MD, recommends performing cataract surgery early to manage IOP in glaucoma. hen you don't perform gonioscopy, said Douglas J. Rhee, MD, Boston, you potentially miss catching not just narrow or closed angles, but plateau iris and peripheral anterior synechiae (PAS). It seems like an obvious point to make, until you consider the strange statistics Dr. Rhee presented: 45% of patients did not receive gonioscopy within either 12 months prior to or six months following an initial diag- nosis of primary open-angle glaucoma. He suggested establishing a protocol in which gonioscopy was performed in the clinic after IOP measurement and before the patient's pupils are dilated. Speaker after speaker at the rapid-fire "Angle Closure Glaucoma from A to Z" symposium would return to gonioscopy like a beacon, if only because the procedure is so clearly useful in managing patients. continued on page 18 Femtosecond lasers provide promising enhancement to astigmatism management by Enette Ngoei EyeWorld Contributing Writer F emtosecond laser-assisted arcuate incisions are a novel technique that provides the precision of image-guided laser technology, said Eric D. Donnenfeld, MD, Long Island, N.Y., at a scientific paper session on astigmatism management in intraocular surgery. Dr. Donnenfeld was discussing a paper on the management of astigmatism during cataract surgery with low energy adjustable femtosecond laser arcuate incisions and an intraoperative wavefront aberrometer. He said that limbal relaxing incisions may be a science, but the response remains unpredictable. The variability in responses is due to age, corneal diameter or curvature, pachymetry, corneal biomechanics, and intraocular pressure. On the other hand, femtosecond laser arc incisions are adjustable. The full effect of the incision is not achieved until the incision is manually opened intraoperatively or postop. Surgeons can also titrate the response to the laser by adjusting line spot separation, energy, and the angulation of incision. Dr. Donnenfeld's paper looked at 31 patients who had a 9 mm optical zone arcuate incision at 85% corneal depth. All incisions were created with the LenSx Laser (Alcon, Fort Worth, Texas with 2.2 microjoules/spot and a layer separation of 5 microns. Following IOL placement, WaveTec ORA intraoperative aberrometry (WaveTec Vision, Aliso Viejo, Calif.) was used to selectively open the laser incisions to refine the astigmatism magnitude, Dr. Donnenfeld said. The results showed a 35% reduction in cylinder with making the incisions prior to opening, he said, and 23 of the patients required opening of the second incision. One patient had a flipped axis of 0.5 D, he said, and there was a high correlation between intraoperative aberrometry at the conclusion of surgery and the postop results at one month. Dr. Donnenfeld said that the use of a femtosecond laser system allows for customizable, adjustable, and fully repeatable astigmatic incisions and that intraoperative aberrometry (WaveTec ORA) may be used to titrate and improve results in the operating room. Discussing astigmatic correction with intrastromal and anterior penetrating arcuate incisions using the femtosecond laser, William W. Culbertson, MD, Miami, said that one of the advantages of femtosecond intrastromal astigmatic keratotomy (AK) is that it is minimally invasive. It also does not result in discomfort or epithelial ingrowth and there is less risk of infection, minimal loss of corneal sensation, resulting in a happier patient, he said. The potential disadvantages of using the technology, however, are that it is less powerful (limited to 1.25 D), nomograms are not established, and enhancement (titration) is less straightforward, he said. Dr. Culbertson's paper reviewed results in two different scenarios, one using the IntraLase (Abbott Medical Optics, Santa Ana, Calif.) over a three-year period and one using the Catalys (OptiMedica, Sunnyvale, Calif.) more recently. The IntraLase cases were for post-cataract extraction astigmatism and the Catalys cases were for naturally occurring astigmatism. Dr. Culbertson said the review showed intrastromal femtosecond laser keratotomy is a safe and predictable technique for reducing (debulking) low amounts of corneal astigmatism to refractively negligible levels. Presenting a paper on the reduction of femtosecond astigmatic keratotomy regression with combined simultaneous high-fluence crosslinking (hfCXL), A. John Kanellopoulos, MD, New York, said, "This novel combination of hfCXL may significantly enhance femtosecond AK efficacy allowing for a smaller arc treatment." Dr. Kanellopoulos and colleagues sought to evaluate the safety, efficacy, and clinical parameters in the novel procedure. Fifteen eyes of 13 consecutive patients were evaluated pre- and up to six months postop for: age, UCVA, BSCVA, refraction, cylinder, topographic cylinder change, endothelium and possible complications, Dr. Kanellopoulos said. Two 300 arcuate OCT-guided femtosecond AK incisions were performed with the LenSx Laser at the 7 mm optical zone, 85% depth and following manual incision separation with a Sinskey hook, one drop of 0.1% riboflavin sodium phosphate was administered in one of the incisions and left to soak for 60 seconds. Dr. Kanellopoulos said the CXL incisions showed statistical significance in the meridional astigmatic change to the non-CXL incisions. The study concluded that the technique could result in potentially higher stability and lesser ocular surface symptoms. This novel combination of hfCXL may significantly enhance steep axis flattening in clear cornea cataract surgery, he said. EW Editors' note: Dr. Culbertson has financial interests with OptiMedica. Dr. Donnenfeld has financial interests with Bausch + Lomb (Rochester, N.Y.), Alcon, and Abbott Medical Optics. Dr. Kanellopoulos has financial interests with Alcon and Avedro (Waltham, Mass.).