Comprehending IOL signs and the significance in glued IOL surgery.

Glued intrascleral fi xation is a technique aimed at restoring pseudophakia in patients with posterior capsular dehiscence and represents the theme of fi xing the haptics into the scleral pockets to allow long-term stability with no decentration and tilt.1,2 The technique has evolved from the use of polymethylmethacrylate nonfoldable intraocular lenses (IOLs) to the application of modern three-piece foldable IOLs3 extending all of the advantages of small incision surgery and as a part of combined surgeries.4 In this technique, the unfolding of an IOL with an appreciation of a “Lucky 7” sign (term coined by Thomas Oetting) for the leading haptic and a “C” sign for the trailing haptic is of utmost importance. As the IOL is loaded, the surgeon ensures that the leading haptic extrudes from the cartridge in the form of the “Lucky 7” (Figure 1A). The initial short portion of the “7” should be protruding to facilitate grasping by the glued IOL forceps, ensuring safe IOL unfolding and nullifying the chances of an IOL drop. The IOL is unfolded and the injector is withdrawn at the end so that the trailing haptic lies at the corneal incision. The trailing haptic showcases an “Upright C” sign at this stage (Figure 1B) (Video 1, available in the online version of this article). The surgeon should be alert for the inability to decipher the “Lucky 7” sign or any variation such as folding the haptic in the cartridge for the leading haptic because any sudden, jerky, uncontrolled unfolding can lead to an IOL drop and the IOL injection should be withheld if possible. If folded in the cartridge, the haptic can be straightened out with an IOL dialer (Figure 1C) and a “Lucky 7” sign can be appreciated. If the IOL has already unfolded in a reverse fashion (Figure 1D), the surgeon can fl ip the IOL upside down in the eye and proceed with the surgery. Appreciation of an “Upright C” sign for the trailing haptic in the anterior chamber instead of at the corneal incision is a matter of concern and should be taken as a warning sign because slippage of the leading haptic at this juncture can lead to an IOL drop. The importance of “Z” and “S” signs has been highlighted for IOL unfolding because the angulation and geometry of the IOL have different optical results and undesirable effective lens position in the eye if inserted upside down. In glued IOL surgery, the horizon of error for IOL unfolding is negligible due to absence of posterior capsule. It is imperative for the surgeon to identify this problem at the beginning of an IOL injection. At this juncture, the appreciation of the “Lucky 7” sign comes into play because it is still possible to abort the IOL insertion, withdraw the injector, and load the IOL again. By comprehending these signs, the surgeon can overcome the hurdles, taking another small step in our pursuit of safe, less invasive glued IOL surgery.