17 Glued Intraocular Lens Position: An Ocular Coherence Tomography Assessment
Fibrin glue, which has been used for various indications in ophthalmology, has been known to provide good surgical adhesion. 1 , 2 , 3 Glued intraocular lens (IOL) technique is one such indication in which tissue glue has been used primarily for IOL implantation. 4 An anatomical position similar to a natural lens gives it an additional advantage compared with the anterior-chamber intraocular lenses. Maggi and Maggi pioneered the initial sutureless IOL fixation in eyes with deficient posterior capsule in 1997. 5 In 2006, Gabor Scharioth introduced transscleral needle fixation of IOLs in eyes with deficient capsules. 6 In 2007, Agarwal et al introduced the glued IOL technique, which comprised glued intrascleral haptic fixation of a posterior chamber IOL. 4 In this chapter, we analyze the position of glued IOL with high-speed anterior-segment optical coherence tomography (OCT).
Localized peritomy at the site of exit of the IOL haptics is done with the patient under peribulbar anesthesia. Two partial-thickness limbal-based scleral flaps about 2.5 × 2.5 mm are created exactly 180 degrees diagonally (use scleral marker) apart. An infusion cannula or anterior-chamber maintainer is inserted. One can use a 20- or 23-gauge trocar cannula for infusion. Positioning of the infusion cannula should be in the pars plana, about 3 mm from the limbus. Anterior-segment surgeons can use an anterior-chamber maintainer. Two straight sclerotomies with a 20-gauge needle are made about 1 to 1.5 mm from the limbus under the existing scleral flaps, followed by vitrectomy via pars plana or anterior route to remove all vitreous traction. A corneoscleral tunnel incision is then prepared for introducing the IOL in case of a nonfoldable IOL or a corneal incision with a keratome in the case of an injectable three-piece foldable IOL.
The IOL cartridge is passed into the anterior chamber. The glued IOL forceps (MicroSurgical Technology [MST], Redmond, WA) is then passed through the sclerotomy, and the tip of the haptic is grasped (Fig. 17.1). The IOL is then gradually injected into the eye. Once the optic is unfolded, the glued IOL forceps is used to pull the haptic out and externalize it. The haptic is then held by an assistant or silicone ties. The surgeon now flexes the second haptic into the anterior chamber into the jaws of the glued IOL forceps introduced through the second sclerotomy using the handshake technique (Fig. 17.2). 7 This haptic is also thus externalized. A limbus parallel scleral tunnel is made with a 26-gauge bent needle on either side at the point of haptic externalization. The haptic tips are then tucked into the intralamellar scleral tunnel.
Air is then injected into the anterior chamber, and the fluid from the infusion cannula is turned off, which helps to prevent hypotony and also keeps the area of the glue application dry. The reconstituted fibrin glue (Tisseel, Baxter, CA) prepared is injected under the scleral flaps. Local pressure is given over the flaps for about 10 to 20 seconds. The corneoscleral wound is closed using 10–0 monofilament nylon in a nonfoldable three-piece IOL, and in case of foldable IOL, the corneal incision is sealed with fibrin glue. The conjunctiva is closed with the fibrin glue in all eyes irrespective of the type of IOL.
17.3 Anterior-Segment OCT
Cross-sectional imaging of the IOL was done using Visante anterior-segment OCT (Carl Zeiss Meditec, Dublin, CA). Corneal high-resolution quad mode was used. Images were taken in four axes: 180 to 0 degrees, 90 to 270 degrees, 225 to 45 degrees, and 315 to 135 degrees. The optics of the IOL were imaged and referred with the position of iris. The images were then analyzed using the caliper tools in the software of anterior-segment OCT for iris vault. D1 and D2 were measured as the distances in millimeters between the iris margin and the anterior surface of IOL optic (Fig. 17.3). The mean pupil size was kept at 6 to 7 mm in all the eyes by pharmacologic dilatation (0.5% tropicamide). For analysis purposes, OCT images in 180 to 0 degrees (horizontal) and 270 to 90 degrees (vertical) axes has been used. All patients underwent refraction (manifest and autorefractometer), retinoscopy, best-corrected spectacle vision (BCVA; Snellen distant vision acuity charts) and corneal topography (Orbscan, Bausch & Lomb, Rochester, NY). Slit-lamp examination (Topcon slit-lamp imaging system, 25× magnification) was performed, and the IOL position was clinically examined by an experienced ophthalmologist. Ocular residual astigmatism (ORA) using the Alpins method was determined and graphical correlation performed. 8
The inclusion criteria were the minimum 5-year follow-up and preoperative indications of surgical aphakia, posterior capsular rupture, and subluxated cataract; also, the patient’s cooperation for OCT examination is required. Patients of pediatric age group or uncooperative were excluded.