EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.
Issue link: https://digital.eyeworld.org/i/387844
11 EW NEWS & OPINION October 2014 In the journal . . . OCT-derived corneal irregularity study Anastasios John Kanellopoulos, MD, Marianthi Chiridou, OD, George Asimellis, PhD In this prospective case series, investigators honed in on a pool of healthy patients to determine how 3-D corneal pachymetry characteristics varied. Included here were 561 eyes. With the aid of spectral domain anterior segment optical coherence tomography, investigators found that the mean central corneal thickness was 537 microns and the mean minimum corneal thickness was 529 microns. They also determined that the focal thinning indices had a mean of –20.7 microns. For the superonasal inferotemporal area, investigators found there was a mean of 26.32 microns, while in the superior inferior region the mean was 25.34 microns. When age was considered, there were some sig- nificant differences found. In younger patients, the superonasal inferotemporal reading was a mean of 22.19 microns compared with 30.44 microns for older patients. Likewise, for younger patients the mean of the superior inferior corneal measurements was 21.47 versus 29.76 for older patients. Investigators concluded that there's an increased corneal asymmetry found in healthy, older eyes. In future studies, this can possibly serve as a benchmark, they concluded. Topical diquafosol and intraoperative corneal wetting Goichiro Miyake, MD, Ichiro Ota, MD, Kensaku Miyake, MD, Masahiro Zako, MD, PhD, Masayoshi Iwaki, MD, PhD Can pretreating the eye of a cataract patient with diquafosol 3.0% have an effect on the time between corneal irrigation with balanced salt solution and when the image seen first begins to blu , known as corneal wetting? Investigators set out to see how cataract patients would fare in cases where they were pretreated with diquafosol compared with instances where they were not. Prior to surgery, 51 patients were randomly assigned to either take artificial tears 6 times per day for 4 weeks or 1 drop of diquafosol 3.0% ophthalmic solution. Investigators found that for those in the diquafosol group the corneal wetting time when the image began to blur was 50.1 seconds versus 45.3 for those receiving artificial tears, which was statistically significant. They concluded that in cataract patients, pretreatment with diquafosol 3% for 4 weeks improved corneal surface wetting during surgery, which they think likely improves intraoperative optical clarity. Laboratory science: biomechanical corneal changes after iontophoresis transepithelial crosslinking Marco Lombardo, MD, PhD, Sebastiano Serrao, MD, PhD, Marianna Rosati, BS, Pietro Ducoli, MD, Giuseppe Lombardo, MEng, PhD Investigators set out to determine how eyes that had undergone ultraviolet-A transepithelial corneal crosslinking using iontophoresis fared with variable in- traocular pressure. In the experimental study, 4 globes treated with the transep- ithelial crosslinking approach using iontophoresis were compared to another 4 globes on which standard crosslinking had been performed. They then consid- ered how the cornea responded to stress, with changes in corneal shape analyzed as a function of IOP. Just prior to crosslinking, corneal thickness was determined to have increased by 5% after hypotonic riboflavin 5-phosphate sodium 0.1% was used during iontophoresis. Investigators also found that corneal thickness was decreased by 13% after instillation of dextran riboflavin 0.1% solution. Meanwhile at the 5-minute post-treatment mark, there was a 2% reduction in corneal thickness for globes that underwent either procedure. However, anterior corneal stiffness increased by a mean of 1.8 times for iontophoresis and 1.9 times for standard crosslinking. Posterior corneal stiffness increased by 1.7 times with iontophoresis compared with 3.1 times for the standard approach. Investigators concluded that during inflation testing in donor globes, biomechanical strength of the cornea was increased by transepithelial crosslinking using iontophoresis, with stiffness determined to be nearly comparable to the standard approach. EW October 2014 O ver the past 60 years, ASCRS Hall of Fame in- ductee Robert M. Sinskey, MD, faced challenges in garnering widespread ac- ceptance of his nystagmus treatment procedure. Today, following the successful treatment of horizontal nystagmus in a 7-year-old patient (by pediatric ophthalmologist Robert W. Lingua, MD), the Uni- versity of California Irvine Gavin Herbert Eye Institute receives hun- dreds of requests for the procedure. Nystagmus is a condition punctu- ated by rapid, uncontrollable eye movements that can cause function- al blindness in children and adults. It was in 1960 that Dr. Sinskey first explored nystagmus treatments with monkeys. Previous treatments for the condition involved drugs or the rearrangement of eye muscles, which kept shaking muscles intact. The former ASCRS president's horizontal nystagmus treatment procedure involves the removal of the medial and lateral rectus muscles, as far back as possible, using an enucleation snare. Dr. Sinskey first successfully performed the procedure on 2 children in 1962. His work with nystagmus treatments was put on hold when his primary focus shifted to cataract surgery. In addition to creating the modified J-loop IOL, D . Sinskey invented several surgical instru- ments. He also popularized the use of phacoemulsification, low-power IOLs, and IOLs in pediatric cataract patients. It was not until a chance in- troduction with a patient suffering from nystagmus that Dr. Sinskey's focus returned to the procedure. At the time, the patient compensated for his shaky vision by nodding his head, the aesthetics of which made it difficult to secure a job. Fortunat - ly, Dr. Sinskey's procedure was a success, and the patient's clear vision helped him to develop a career in psychiatry. After another achievement in treating nystagmus, Dr. Sinskey reached out to the wider oph- thalmic community. As with the introduction of phaco, Dr. Sinskey's colleagues did not quickly seek to adopt his out-of-the box nystagmus treatment procedure. Many were Nystagmus treatment procedure was decades in the making by Abbie B. Elliott ASCRS•ASOA Communications Manager Dr. and Mrs. Sinskey Source: Robert Sinskey, MD ASCRS update continued on page 13