A New Technique For Transscleral Suture Fixation Of Posterior Chamber Intraocular Lens Without Triangular Scleral Flaps

Background:Implantation of intraocular lens (IOL) has become the standard of care in the aphakic eye. Ideally, the IOL is placed in the capsular bag, which affords stable fixation at a position closest to the nodal point of the eye. However, this is not always the case. Congenital weakness of the lens zonules in various conditions, trauma, and surgical complications of cataract surgery are just some examples. We reviewed and compared the methods that have been devised to allow IOL implantation in the absence of capsular or zonular support. These include anterior chamber angle and iris-fixated lens, posterior chamber iris- and transscleral-sutured lens. Usually we like to choose transscleral-sutured posterior chamber IOL (PCIOL). Being located in a position closest to the original lens, PCIOL possess the inherent advantages of having a position close to the nodal point of the eye and also of being close to the eye's rotational axis. Apart from the optical benefit of minimal aniseikonia when compared with the phakic eye, this position keeps IOL furthest from the corneal endothelium and avoids disturbance to the trabecular meshwork. This may also provide a mechanical barrier against vitreous movement or diffusion of vasoactive substances that could lead to retinal detachment or cystoid macular edema (CME). But we do not have useful method to avoid its peculiar complication of suture exposure through the conjunctiva. Most doctors in the world use a classic method of triangular scleral flaps. Making scleral flaps need more operational time and become more difficult in difficult cases. We tried to improve this method.Objective: The aim of this study was to describe a new technique for transscleral suturing of PCIOL without triangular scleral flaps, to investigate the clinical efficacy.Methods: Clinical case series. This retrospective review comprised the twenty-three cases of consecutive patients who had transscleral sutured PCIOL surgery performed in the Fourth Military Medical University XiJing Hospital from April 2005 to November 2009 by the same surgeon using a technique without triangular scleral flaps. The series included aphakia after trauma in 7 eyes, IOL dislocation after extracapsular cataract extraction (ECCE) in 5 eyes, and lens dislocation because of blunt trauma, Marfan's syndrome, pseudo exfoliation syndrome in 11 eyes. Indications of operation included aphakia without capsular support, lens or IOL dislocation, corrected visual acuity better than naked visual acuity, corneal endothelial cells counting>1000/ mm2. We chose 10-0 PMMA suture line with a bent needle and a straight needle in our operation. The straight needle was used to pierce the eye from 12 o'clock to 6 o'clock 3 mm behind the limbus, and the bent needle was used for lamellar-sclera suture of 2 mm needle bite 2mm next to the needle hole at 12 o'clock after IOL implantation, which formed a suture ring of 3-4mm length. After tying the ring and the end of suture, the suture ring was made lying flat by the end of suture rotating the loop 1-2 times. Three intra-scleral"Z"sutures of 3 mm needle pitch were made, and this kept the ends of suture line hiding. The anatomic and functional outcome of surgery was determined during a follow-up of 3 to 55 months.Results: PCIOLs were successful implanted in all of 23 eyes, the dislocation of IOLs did not cccur in 22 eyes. No one had erosion of suture knots through the conjunctiva. No patients felt foreign body sensation. The postoperative final BCVA improved in 15 eyes, not changed in 7 eyes, and dropped one line in 1 eye. The postoperative final BCVA was mainly associated with the preoperative condition of the eye, such as cornea scar, optic contusion and macular contusion. The PCIOL was slightly decentered in 1 eye which was 1 haptic placed, intraocular hypertension was present in 2 eyes for a short-term, intraocular low-tension was present in 3 eyes with choroid edema. Moreover, a little bit vitreous hemorrhage, hyphema and macular edema were present in one eye each. All the complications above were subsided spontaneously or by drug treatment. Retinal detachment occurred in 1 eye two months after operation, which was cured after surgery of vitrectomy and silicone oil tamponade.Conclusion: This technique for transscleral suturing of PCIOL without triangular scleral flaps is safe and effective, which mainly minimizes the risk of erosion of suture knots through the conjunctiva.