Two-way adjustable double-knots intrascleral fixation and single sclerotomy looping technique: a novel minimal invasive adjustable intraocular lens fixation technique

Abstract

Background: IOL fixation without capsular support presents challenges for surgeons. Although innovative techniques were developed to address subluxated IOLs, adjustable IOL fixation methods are seldom reported. We introduce a novel two-way adjustable double-knots intrascleral fixation combined with single sclerotomy looping technique for fixing intraocular lenses (IOL) or IOL-capsular bags.

Methods: A bent 30-gauge needle threaded with 8 - 0 polypropylene was introduced into the eye. A gripping forceps assisted the haptic looping. Two overhand knots were made with 8 - 0 polypropylene thread. The knots were incarcerated into a scleral tunnel made by a 30-gauge needle, with two ends of the thread left at each side of the tunnel. The IOL was adjusted to the premium position with adequate tension by pulling either end of the threads. The study included 19 eyes with aphakia, subluxated IOL-capsular bags, or subluxated crystalline lenses. The mean followed up period was 18.9 ± 7.1 months with evaluations of uncorrected visual acuity (UCVA), intraocular pressure, slit-lamp examination, and swept-source optical coherence tomography of the anterior segment.

Results: UCVA increased from 1.28 ± 0.74 at baseline to 0.44 ± 0.51 (logMAR) at final visit (P < 0.001). All IOLs were fixed well-centered. The mean IOL tilt was 3.5°±1.1°. Postoperative complications included transient IOP elevation (15.8%), hypotony (10.5%), and cystoid edema (5.3%) which resolved within 4 weeks.

Conclusions: We presented a novel adjustable technique for IOL fixation, which stabilize IOLs by using an intrascleral double-knots structure. This technique minimized surgical manipulations by using a single sclerotomy looping technique without large conjunctival dissection and scleral flap creation. The technique offers a reliable and optimal IOL positioning and improved visual outcomes in patients undergoing scleral fixed IOL implantation.

Keywords: Adjustable; Intraocular lens; Surgical technique; Transscleral fixation.

Fig. 1

Schematic figure demonstrating surgical steps of two-way adjustable double-knots (TADK) intrascleral fixation with single sclerotomy looping (SSL) technique for IOL fixation. SSL(A-C). A, The 30-gauge needle with the leading end of 8 − 0 polypropylene thread was introduced into the eye 2.5 mm from the limbus at the fixation site. The tip of the 30-gauge needle passed through the closed loop of the haptic from back to front. B, The 23-gauge gripping forceps grasped the thread out of the 30-gauge needle from the front of the haptic. The 30-gauge needle was drawn back a little bit. C, The 30-gauge needle was forwarded to the front of the haptic. The 23-gauge gripping forceps delivered the leading end of the thread back to the tip of the 30-gauge needle. D, The 30-gauge needle was withdrawn from the eye and the leading end of the polypropylene thread was externalized from the same sclerotomy at the fixation site. TADK (e-f) E, Two 3-1-1 overhand knots with an interval of 1.5 mm were made with both ends of the thread 3.0 mm from the sclerotomy. F, The leading end of the thread was pulled to lead both knots entering the scleral tunnel and the other end of the thread was left at the beginning of the tunnel

Fig. 2

IOL tilt measured on SS-OCT image. The reference line was determined as the line passing through the iris-cornea angles on either side of the image. The angle between the line passing through the horizontal axis of IOL and the reference line was measured. The IOL tilt was measured in both the vertical and horizontal plans

Fig. 3

Postoperative slit-lamp photography of the left eye of a patient. The scleral tunnels were on the superior temporal and inferior nasal sclera. A, Slit-lamp image showing no conjunctival scarring and inflammation of the inferior nasal sclera. The arrow indicated the scleral tunnel. B, Slit-lamp image showing no conjunctival scarring and inflammation of the superior temporal sclera. The arrow indicated the scleral tunnel

Fig. 4

Postoperative evaluation of IOL position. A, Slit-lamp image showing a well centered IOL. B, Swept-source OCT of the anterior segment showing no tilt of the IOL