Corneal Relaxing Incision Technique

Corneal (or Limbal) Relaxing Incisions are an effective method to manage pre-existing corneal astigmatism. In this video I demonstrate my technique of relaxing incisions. Pre-operative keratometry assessment with automated (IOLMaster or Lenstar), manual (Juval), topographic (Humphrey Atlas) methods is mandatory, and I often like to correlate these devices with the patient's glasses prescription and/or refraction. Topographic analysis is imperative to avoid operating on non-orthogonal or irregular astigmatism. The Nichamin NAPA nomogram is used (available at lricalculator.com) and the steep incision is selected for relaxation. The main wound is placed either on the steep or flat meridian as I find this avoids any unusual healing processes. Finally, the patient's limbus is marked pre-operatively at a slit lamp using a Sinskey hook to impress the epithelium at 3, 6 and 9 o'clock. These marks are aligned with a modified Mendez ring and the desired meridian for relaxation as well as the main incision are marked. The length of the incisions are then denoted. All intra-operative marks are made using methylene blue dye (Hurricane Medical) on either a Sinskey hook or Bores two-ray marker. The zero setting of the blade is checked and then the barrel is rotated up to the desired depth; if the desired mark is passed by error, rotate the barrel below the desired depth and re-rotate up to the desired depth as this avoids inadvertent over-penetration which can result from play in the blade mechanism. The blade is plunged into the corneal tissue and drawn towards the surgeon. The globe is fixated with a ring or if preferred a toothed forcep. Techniques to avoid epithelial stripping and create a more arcuate cut are demonstrated. Examples of placing the main wound 90 degrees from the relaxing incisions as well as coincident with the steep meridian are included. Video by Jason Jones, MD.