EyeWorld India December 2017 Issue

continued on page 42 September 2017 Dec EWAP SECONDARY FEATURE 41 Corneal crosslinking: Fast and furious versus low and slow by Stefanie Petrou Binder, MD, EyeWorld Contributing Writer AT A GLANCE • CXL is the current paradigm used to stabilize the cornea in patients with keratoconus. • The global consensus on keratoconus and ectatic diseases achieved consensus on diagnosis, nonsurgical treatment, and surgical treatment of keratoconus. • Experts do not agree on the bene ts of accelerated CXL protocols compared to the standard Dresden protocol. • Shorter ophthalmic surgery times increase patient comfort during the procedure. Is using the standard low intensity protocol for corneal crosslinking still the best way to go? O verall, shorter ophthal- mic surgical techniques are preferable and can be far more comfort- able for patients, but do they forfeit safety and efficacy? When it comes to corneal crosslink- ing (CXL), some experts think it might pay to take your time. EyeWorld spoke with two special- ists to understand the status of CXL internationally and discuss current viewpoints. Corneal CXL combines the use of riboflavin (vitamin B2) drops and ultraviolet (UV) light to reshape and stiffen the cornea in patients with corneal ectasias, such as keratoconus, a degenera- tive non-inflammatory disease of the cornea in which the central or paracentral cornea undergoes progressive thinning and steep- ening, causing irregular astig- matism. The procedure has been performed in Europe for roughly 15 years, but has only been FDA approved since 2016. Current paradigm “Corneal crosslinking interna- tionally has been transformed into the current paradigm for sta- bilizing progressive keratoconus and ectasia,” 1 said John Kanel- lopoulos, MD , medical director, LaserVision.gr Institute, Athens, Greece, and clinical professor of ophthalmology, New York Uni- versity Medical School, New York. “In several parts of the world, the clinical consensus is that it should be used prophylactically in high risk patients, for instance, young patients less than 25 who show even the subtlest clinical signs of keratoconus, such as topographic, topometric, or epi- thelial mapping irregularities that are consistent with early kerato- conus. 2 With the FDA approval of corneal crosslinking last year, it is now a globally established proce- dure for this purpose.” 3 Before ophthalmologists can treat keratoconus and decide on surgical or nonsurgical measures, ectasia needs to be defined and physicians require guidelines. Dr. Kanellopoulos referred to the global consensus on keratoconus and ectatic diseases 4 that gives definitions and recommendations for the treatment of keratoconus to help physicians navigate their way through the various contro- versies in diagnosis and man- agement. The global consensus project involved the use of a mod- ified Delphi technique, followed by three questionnaire rounds, as well as face-to-face meetings with 36 expert ophthalmology pan- elists, to achieve consensus on definition/diagnosis, nonsurgical treatment, and surgical treatment of keratoconus, where a two- thirds majority was required for consensus. The consensus project defined ectasia progression as a consistent change over time in at least two parameters: steepening of the an- terior corneal surface, steepening of the posterior corneal surface, or thinning and/or an increase in the rate of corneal thickness change from the periphery to the thinnest point, which are above the normal variability (noise) of the measurement system. Although progression is often accompanied by a decrease in BSCVA, a change in both UCVA and BSCVA is not required to document progression. The panel agreed that specific quantitative technology and machine-specific data were lacking to further define progression. They recom- mended that examinations in younger patients be shorter and involve the use of the same meas- uring platform for consistency. According to the global con- sensus panelists, halting disease progression and visual rehabilita- tion were the two most important goals of nonsurgical therapy. To this end, they advised avoid- ing eye rubbing but supported the use of topical anti-allergic medications and lubricants. The panelists agreed that there was no direct relationship between keratoconus and dry eye and Slit lamp photograph of the same eye 2 weeks after epithelium-off CXL. There is mild diffuse post-CXL corneal haze. Vogt’s striae of keratoconus can be seen at the inferior pupil.